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CLINICAL RESEARCH ARTICLE
Risk factors for lower extremity amputation in patients
with diabetic foot ulcers: a hospital-based case
control
study
Tjokorda Gde Dalem Pemayun, MD, PhD
1
*, Ridho M. Naibaho, MD
2
,
Diana Novitasari, MD
2
, Nurmilawati Amin, MD
2
and Tania Tedjo
Minuljo, MD
2
1
Subdivision of Endocrinology, Metabolism and Diabetes, Department of Medicine, Medical Faculty of
Diponegoro University, Dr. Kariadi General Hospital, Semarang, Indonesia;
2
Resident of Endocrinology,
Metabolism and Diabetes, Department of Medicine, Medical Faculty of Diponegoro University, Dr. Kariadi
General Hospital, Semarang, Indonesia
Background: Diabetic foot ulcers (DFU) may cause significant morbidity and lower extremity amputation
(LEA) due to diabetic foot problems can occur more often compared to the general population. The purpose
of the present study was to use an epidemiological design to determine and to quantify the risk factors of
subsequent amputation in hospitalized DFU patients.
Methods: We performed a hospital-based, casecontrol study of 47 DFU patients with LEA and 47 control
DFU patients without LEA. The control subjects were matched to cases in respect to age (95 years), sex, and
nutritional status, with ratio of 1:1. This study was conducted in Dr. Kariadi General Hospital Semarang
between January 2012 and December 2014. Patients’ demographical data and all risk factors-related
information were collected from clinical records using a short structural chart. Using LEA as the outcome
variable, we calculated odds ratios (ORs) and 95% confidence intervals (CIs) by logistic regression. Univariate
and stepwise logistic regression analyses were used to assess the independent effect of selected risk factors
associated with LEA. The data were analyzed in SPSS version 21.
Results: There were 47 casecontrol pairs, all of which were diagnosed with type 2 diabetes mellitus. Seven
potential independent variables show a promise of influence, the latter being defined as p50.15 upon
univariate analysis. Multivariable logistic regression identified levels of HbA1c ]8% (OR 20.47, 95% CI
3.12134.31; p0.002), presence of peripheral arterial disease (PAD) (OR 12.97, 95% CI 3.4448.88;
pB0.001), hypertriglyceridemia (OR 5.58, 95% CI 1.7417.91; p0.004), and hypertension (OR 3.67, 95%
CI 1.1411.79; p0.028) as the independent risk factors associated with subsequent LEA in DFU.
Conclusions: Several risk factors for LEA were identified. We found that HbA1c ]8%, PAD, hypertriglyceri-
demia, and hypertension have been recognized as the predictors of LEA in this study. Good glycemic control,
active investigation against PAD, and management of comorbidities such as hypertriglyceridemia and
hypertension are considered important to reduce amputation risk.
Keywords: diabetic foot ulcers; hospitalized patients; risk factors; amputation
*Correspondence to: Tjokorda Gde Dalem Pemayun, Consultant of Endocrinology, Metabolism and
Diabetes, Department of Medicine, Medical Faculty of Diponegoro University, Dr. Kariadi General
Hospital, Dr. Soetomo Street, No. 16, Semarang 50244, Indonesia, Email: tjokdalem_smg@yahoo.com
Received: 4 September 2015; Revised: 1 November 2015; Accepted: 1 November 2015; Published: 7 December 2015
D
iabetes mellitus is the most common endocrine
disorder known for its multifaceted complica-
tions, including diabetic foot ulcers (DFU)
which often result in amputation as one of the worst out-
comes (1). Among persons with diabetes, the prevalence
of foot ulcers ranges from 4 to 10% and its lifetime
incidence may be as high as 25% (2). Foot ulceration
poses a distinct barrier to conservative therapies attrib-
uted to difficulty in properly offloading the wounds, in-
ability to provide daily foot hygiene, and compromised
distal vascular flow in diabetes. DFU are difficult to
treat, frequently get infected, and become a leading cause
of diabetes-related hospital admission (1, 3). Compared to
healthy persons, diabetes mellitus holds a 15- to 20-fold
increased risk of lower extremity amputations (LEA) and
the majority of diabetes amputation are reported to be
DIABETIC
FOOT & ANKLE
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1
Citation: Diabetic Foot & Ankle 2015, 6: 29629 - http://dx.doi.org/10.3402/dfa.v6.29629
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preceded (up to 85%) by a poor healing ulcer (4). In the
future, diabetes-related LEA will remain a source of sig-
nificant morbidity and also mortality, considering the
rapidly growing diabetes population worldwide and the
high incidence of DFU (5).
According to the Global Lower Extremity Study
Group, LEA can be defined as a complete loss of any
part of the lower extremity irrespective of the causes (6).
Approximately 82% of LEAs are performed on patients
with diabetes, most of which follows foot ulceration (7).
The pathway to ulceration and finally LEA may include
essential contribution from underlying diabetes-related
pathophysiology (neuropathy, peripheral arterial disease
(PAD), foot deformity and limited joint mobility), initiat-
ing environments (trauma), subsequent infection, and
healing complications (8). LEA is performed for various
indications including severe soft-tissue infection, osteo-
myelitis, peripheral arterial occlusion, and gangrene.
Following a LEA surgery, the impact of this procedure
on an individual patient is very enormous so that ampu-
tation is always considered as the last resort of any
unsalvageable limb (9). Apart from its causes, all attempts
should be made to avoid amputation once DFU has
developed or presents itself in the hospital (1, 4, 5).
The diabetic foot follows a common pathway that
begins with a small ulcer or surgical wound. The majority
of DFU (6080%) will heal, whereas 1015% of them
will remain active, and up to 24% of them will finally lead
to LEA (1, 4, 8). The question is why some patients
with DFU be necessary for LEA while others were not.
Previous studies have revealed that duration of diabetes
mellitus (10, 11), previous amputation or foot ulceration
(10, 1214), poor glycemic control (10, 12, 13, 1518),
hypertension (15, 19), dyslipidemia (11, 15, 19), presence
of PAD (11, 12, 14, 18, 20), peripheral neuropathy (13, 14,
20), osteomyelitis (19, 21), and wound severity (22, 23) are
independent predictors for LEA. Additional factors
include older age (18, 22), smoking history (22, 23),
anemia (18), leukocytosis (18, 19, 22), hypoalbuminemia
(20, 22), as well as presence of other microvascular (10, 11,
1315, 17, 19, 21) and macrovascular comorbidities (13,
15, 22). However, different studies show different results
and the published data that identify such risk factors for
diabetes-related LEA in Indonesia are scanty. The risk
factors have not been clarified in our center so that the
scope for understanding the reasons for an LEA risk
reduction is limited.
We performed a casecontrol study to assess the
magnitude and common determinants of LEA in hospi-
talized patients with DFU from Dr. Kariadi General
Hospital Semarang. The hypothesis underlying this ana-
lytical investigation was that there may be several differ-
ences in the risk factors pattern among DFU that warrant
amputation surgery. The inclusion criteria were designed
to allow the enrollment of a representative group of DFU
similar to ‘real world’ situations in developing countries
where most patients were ambulatory, self-medicated at
home, have a considerable delay before hospital admis-
sion, may have their diabetes poorly controlled, and have
several sociocultural practices such as walking barefoot,
use of herbal healer, and so on (5). Identification of vari-
ables and to suggest modifiable factors is the first step in
the pathway for the creation of preventive and/or ther-
apeutic programs to reduce LEA rates at institutional
levels with local resources.
Material and methods
Study area and background
This study used an observational design and was con-
ducted in Dr. Kariadi General Hospital, Semarang Dis-
trict, Central java Province, Indonesia. Dr. Kariadi
General Hospital is a tertiary care hospital, which is the
central referral and main teaching hospital of the Medical
Faculty of Diponegoro University. The incidence of LEA
was determined by reviewing the medical records. For this
study, the complete list of DFU and LEA population was
identified from hospital databases (operating theater and
medical record). Ulcer and gangrene due to reasons other
than diabetes mellitus, and signs of acute peripheral
arterial thrombosis were not included in this study.
Traumatic amputations and those unrelated to diabetes
mellitus were also excluded. The study was designed as a
matched casecontrol study (24). Assuming the propor-
tion of DFU with amputation to be 39.5% (25), a sample
size of at least 23 in each group was needed to detect an
odds ratio (OR) of 2.0 at 95% level of confidence interval
(CI) with a power of 90% (two tails) (26). Ethical approval
for this study was given by the Commitee of the Medical
Faculty of Diponegoro University and Dr. Kariadi Gen-
eral Hospital.
Subjects
In the present study, we have identified 232 hospitaliza-
tions involving 186 patients at our institutions who had
foot ulcerations (International Classification of Disease,
10th Revision [ICD-10] codes E11.6 and E14.6) with
diabetes. Diabetes was defined as at least one record of
ICD-10 code E10 (type 1 diabetes) or E11 (type 2 diabetes).
We designed the study to have 1:1 matching, with one
subject control for each case (24, 27). The confounding
factors such as age, sex, and nutritional status were
considered in the casecontrol matching. The presence of
the following factors was evaluated to determine if they
predicted either amputation or not: demographic char-
acteristics (duration of ulcer, duration of diabetes since
diagnosed, sort of diabetes treatment), clinical features
(presence and assessment of diabetic peripheral poly-
neuropathy, retinopathy, nephropathy, PAD, and type of
diabetic foot), level of glycemic control, and several
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Citation: Diabetic Foot & Ankle 2015, 6: 29629 - http://dx.doi.org/10.3402/dfa.v6.29629
laboratory data. These possible risk factors were chosen
because they were common risk factors for LEA cited from
the previous studies (1023). The study period was January
2012 to December 2014 and medical records that contain
missing data on any of the stratified information were
excluded from analysis.
Treatment settings
We utilized a standard protocol for the management of
patients hospitalized because of DFU which included off-
loading, assessment of vascular status, assessment of
neuropathy, treatment of PAD, and regular wound de-
bridement. In general, DFU patients with signs of
significant infection, such as extensive cellulitis, necrotiz-
ing fasciitis, deep abscess or osteomyelitis, septic foot, or
presence of gangrenous tissue were hospitalized for inten-
sive surgical management. All patients were placed on bed
rest for pressure relief and appropriate antibiotic therapy
was administered when infection was present. DFU
subsequently were managed according to the severity of
lesions; debridement, incision/drainage, and amputation
were done as necessary. All of these patients were under
the care of a multidisciplinary team of endocrinologist,
infectious disease specialist, cardiologist, vascular sur-
geon, orthopedic surgeon, plastic surgeon, nutritionist,
internal medicine residents, and nursing personnel.
Measurements of potential risk factors
We abstracted the medical records for each hospitalization
and the operative reports were read to evaluate the exact
surgical procedure performed. By using a pre-preformed
customized chart, we collected the information regarding
the patient’s age, sex, body mass index (BMI), admission
dates, duration of diabetes mellitus, therapeutic regimen,
characterization of ulcer, ulcer duration, hemoglobin level,
leukocytes count, creatinine serum, admission plasma
glucose, fasting plasma glucose (FPG), HbA1c, and lipid
profile (total cholesterol, fasting triglycerides, low-density
lipoprotein (LDL)-cholesterol, and high-density lipopro-
tein (HDL)-cholesterol). Regarding lipid profile, the cut-
off points for high total cholesterol (200 mg/dL), high
triglycerides (150 mg/dL), high LDL-cholesterol (100
mg/dL), and low HDL-cholesterol ( B40mg/dL) were
based on The National Cholesterol Education Program
(28). The cut-off points for high plasma glucose (]200
mg/dL), high FPG ( ]126 mg/dL), and high HbA1c
(]8%) were based on the Indonesian Diabetes Associa-
tion definition for poor glycemic control (29). BMI is
defined as ratio of weight (in kg) to height (in meters
squared). Diabetes micro- and macrovascular complica-
tions (retinopathy, nephropathy, neuropathy, cerebrovas-
cular, cardiovascular, and PAD) were classified in
accordance with the Diabetes Complications Severity
Index created by Young et al. (30).
The diagnosis of diabetes mellitus was measured at the
initial admission. We further classified participants with
diagnosed diabetes mellitus into the following treatment
categories: 1) no pharmacological treatment, 2) oral
hypoglycemic medication, and 3) use of insulin treatment
(insulin alone or in combination with oral agents). Hyper-
tension was considered to be present if patients were
taking antihypertensive medicine or had elevated blood
pressure measurement over systolic 140 and/or diastolic 90
mmHg. Retinopathy was defined as the presence of retinal
hemorrhage exudate or microaneurysms on funduscopic
examination by an ophthalmologist. The presence of
diabetic nephropathy was defined by plasma creatinine
1.5 mg/dL or persistent proteinuria. Presence of coro-
nary artery disease (CAD) was defined by its evidence on
electrocardiography, echocardiography, or coronary an-
giography (30). The data regarding particular diseases
such as myocardial infarction, congestive heart failure,
cerebrovascular disease, and chronic renal disease also
were collected from the patient’s case sheets.
The presence of PAD (PAD; ICD-10 codes E11.5, E14.5
or unspecific PAD; ICD-10 code I73.9) was recorded by a
history of intermittent claudication, non-palpable or
weakly palpable pedal pulses, ankle-brachial index less
than 0.9, or angiography showing significant stenosis in
low extremity arteries. Vascular intervention at any time
was also recorded as positive for PAD. Decrease or loss in
sensation (vibration, light touch, pain, awareness of
temperature differences) in a glove and stocking distribu-
tion, or loss of deep tendon reflex and absence of per-
ception of the Semmes-Weinstein monofilament (10-g) at
2 of 10 standard plantar sites of either foot indicated
peripheral neuropathy. The ICD-10 codes E11.4 and E14.4
(diabetes with neurological complications) were used for
diabetic polyneuropathy. According to the presence of
neuropathy and/or PAD, ulcers were divided into neuro-
pathic, ischemic, and neuroischemic origin (1, 31).
Definition of wound grading and indications for LEA
The DFU were graded according to Wagner classification
(grade 0: high-risk foot, grade 1: superficial ulcer, grade 2:
deep ulcer penetrating to tendon, bone, or joint, grade 3:
deep ulcer with abscess or osteomyelitis, grade 4: localized
gangrene, and grade 5: extensive gangrene) (32). In this
study, a foot ulcer was defined as a full-thickness skin
break occurring distal to the malleolus at least to Wagner
grade 1, applying definition from previous study (33).
Depth of ulcer was categorized as: grade 1 (ulceration
extending to subcutaneous tissue), grade 2 (ulceration in-
volving the joint capsule or tendon), and grade 3 (ulcera-
tion extending into bone or within a joint) (34). The
diagnosis of diabetic foot infection was made on clinical
grounds and stratified using PEDIS system developed by
the International Working Group on the Diabetic Foot
(IWGDF). PEDIS itself stands for perfusion, extent (size),
depth (tissue loss), infection, and sensation (neuropathy)
(31, 34).
Risk factors for amputation in patients with diabetic foot ulcer
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The primary outcome of interest in this study was an
incident of LEA following DFU admission. Almost all
LEAs were conducted in hospital settings so they could be
properly registered in hospital discharge data. The indica-
tion for LEA included severe soft tissue infection,
osteomyelitis, or gangrene (1, 9). This decision was made
by internist-endocrinologist and surgeon conference; then
the vascular or orthopedic staff executed the amputation
surgery. Minor amputations were included if they were
within one of the following categories: partial toe amputa-
tion, complete toe disarticulation at the metatarsophalan-
geal joint, ray (toe and metatarsal) amputation, or
proximal foot amputation (transmetatarsal, Lisfranc’s,
Chopart’s, and Syme’s). Transtibial and transfemoral am-
putation were considered as major amputations (9). In our
series, most major LEAs were performed in extensive
gangrenous foot (Wagner grade 5) that associated with
acute thrombosis occlusion. We excluded DFU in accor-
dance to Wagner grade 5 in patient selection for statistical
reasons.
Casecontrol classification
Cases
Case subjects included DFU patients admitted to Dr.
Kariadi General Hospital with at least one subsequent
lower extremity amputation (ICD-10 codes Z89.4, Z89.5,
Z89.6, Z89.7, and Z89.9) during the study period. A
manual review of operation theater database was con-
ducted to identify LEAs performed between January 2012
and December 2014. In total 96 amputation surgeries were
initially identified. Forty-nine patients were subsequently
excluded for the following reasons: DFUs included in
Wagner grade 5 lesion, 17; unable to retrieve a complete
medical record, 21; unable to find a control suitable for
matching, 11. This left 47 patients with LEA in confirmed
diabetic patients available for the study. Of these, 37
patients (78.7%) had minor amputation and the remainder
10 patients (21.3%) had major amputation.
Controls
Control subjects were patients with DFU who had never
undergone LEA during the time of hospitalization.
Matching was done by pairing patients with sex and birth
date within 5 years in the chronological order in which
they were admitted to the study. The case and control
subjects were also matched for nutritional status based on
their BMI and classified as undernourished, normal
weight, overweight, or obese. An attempt was made to
individually match at least one control per case. In this
process, 43 potential control subjects were excluded
because the necessary data was incomplete or there was
no corresponding match with the case subjects. The final
47 control subjects were verified after all studied patients
had been evaluated and determined that a patient had not
been paired with two matched controls; one control
subject for each case with LEA.
Statistical analysis
Descriptive statistics were obtained to describe the char-
acteristics of the studied population. The initial data
analysis showed the distribution of key variables in all
patients. Continuous variables were presented as the
mean9standard deviation (SD) or geometrical mean
and categorical variables were given as proportions. ORs
and 95% CIs were calculated for various variables that
have been previously reported to be independent LEA risk
factors (1023). The variables of interest were selected and
these potential risk factors were compared on matched
pairs of case and control subjects. ORs greater than
1 indicate an increased LEA risk for the corresponding
variable using a conditional logistic regression. Accord-
ingly, we created a dummy variable for each of the selected
risk factors and examined their effects (adjusted to age,
sex, and nutritional status) on LEA risk. Second, all
potential predictors (variables selected through univariate
analysis with p50.15) were entered simultaneously in a
multivariable logistic regression model that was reduced
using a backward selection method. In the multivariable
logistic regression, the analysis was performed in a full
model. The HosmerLemeshow X
2
goodness-of-fit test
was used for model building (35). After the model
creation, a multivariable score was computed using b
coefficient values and the actual values for covariates for
each variable. The ability of the score to discriminate
between patients who did and did not develop an LEA was
assessed using the Area under the Receiver Operating
Characteristic Curve (ROC) with 95% CI. All tests were
two sided with pB0.05 considered statistically significant
in both univariate and multivariate analysis. The Statis-
tical Package for Social Science (IBM version 21.0; SPSS
Inc., Chicago, USA) was used for all data analysis.
Results
Baseline characteristic and laboratory data
There were 47 cases with LEA at Dr. Kariadi General
Hospital during the study period. In total 94 subjects were
assessed as respondent to 1:1 matching according to sex,
age, and nutritional state. Descriptive information that con-
tains baseline characteristics and laboratory results are
listed in Tables 1 and 2, respectively. All patients had type 2
diabetes mellitus and females were predominant (59.6%).
Almost all of the patients included into the study were
Javanese. The mean age of the patients and their matched
control subjects was 52.697.0 years and the median value
of diabetes duration was 5 years. As for management of
diabetes mellitus, the majority of patients (63.8%) were on
oral hypoglycemic agents. Twenty patients (21.3%) were
just diagnosed with diabetes mellitus at hospital admission.
Glycemic control was poor in the majority of subjects at
the time of admission to the hospital as indicated by their
admission plasma glucose (median value: 325.5 mg/dL),
Tjokorda Gde Dalem Pemayun et al.
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Citation: Diabetic Foot & Ankle 2015, 6: 29629 - http://dx.doi.org/10.3402/dfa.v6.29629
mean FPG (220.6973.5 mg/dL), and mean HbA1c
(11.392.8%). Mixed dyslipidemia characterized by hyper-
triglyceridemia and low level of HDL-cholesterol could be
observed in our patient population. The most common
comorbidities were hypertension (53.2%) and chronic
renal failure (43.6%, on dialysis in 4.2% patients). With
respect to specific diabetes-related vascular complication,
retinopathy can be observed in 92.6% of patients, 68.1%
had peripheral neuropathy, 54.3% had nephropathy, and
40.4% had PAD. As for clinical outcomes, the median
value of length of hospitalization was 15.5 days. The
mortality rate was 5.3% involving total of five patients in
both case and control subjects.
Type of diabetic foot
In our sampled population, DFU had developed within
the median time of 2 weeks (ranged 1 to 72 weeks) before
hospital admission. Thirty-two patients had a previous
history of diabetic foot disease whereas most of them
(66.0%) had never reported any previous ulcer. Fourteen
patients (14.8%) had prior history of LEA due to diabetic
foot. Of the total number of 94 patients with DFU, 40
(42.6%) were classified as neuropathic, 24 (25.5%) were
neuroischemic, 14 (14.9%) were ischemic ulcers, and 16
(17.0%) had no identified underlying factors in respect to
either neuropathy or PAD. Most DFU (48.6%) had already
penetrated into muscle or tendon, 43.6% of them pene-
trated into bone, and 7.4% of ulcers were categorized as
superficial ulcers. When evaluated according to Wagner
classification, the majority of patients (75.5%) were in
grade 3 and grade 4 lesions, respectively 39.4 and 36.2% of
patients. DFU corresponding to Wagner grade 5 were
excluded from the population selection. Additionally,
98.8% of ulcers showed clinical evidence of infection at
presentation. Deep abscess and osteomyelitis were found
in 68 patients (72.3%) whereas in the most severe form,
septicemia occurred in 12 (12.7%) of sampled patients.
Table 1. Baseline characteristics and laboratory data in the
studied population
a
Variables Overall (n94)
Sex
Males 38 (40.4%)
Females 56 (59.6%)
Age (years) 52.697.0
Hospital stay (days) 15.5 (569)
BMI (kg/m
2
) 21.9 (17.532.0)
Systolic blood pressure (mmHg) 134.4923.9
Diastolic blood pressure (mmHg) 80.9912.2
Laboratory data
Hemoglobin (gr %) 9.891.7
Leukocyte 10
3
/mL 17.0 (4.939.5)
Albumin (g/dL) 2.490.6
Creatinine (mg/dL) 1.1 (0.28.8)
Total cholesterol (mg/dL) 159.7940.6
Triglycerides (mg/dL) 153.0 (89383)
LDL-cholesterol (mg/dL) 109.0926.6
HDL-cholesterol (mg/dL) 26.0 (1058)
Discharge status
Recovered (alive) 89 (94.7%)
Deceased (dead) 5 (5.3%)
Data are expressed as number (%), mean9SD, or geometric
mean (95% confidence interval). BMI, body mass index; LDL, low
density lipoprotein; HDL, high density lipoprotein.
a
Case and
control were adjusted for patient’s age, sex, and nutritional status.
Table 2. Characteristics of diabetic foot ulcer and diabetes
complications in the studied population
a
Variables Overall (n94)
Duration of ulcer (week) 2 (172)
Previous DFU 32 (34.0%)
Previous LEA 14 (14.8%)
Type of diabetic foot
Neuropathic 40 (42.6%)
Ischemic 14 (14.9%)
Neuroischemic 24 (25.5%)
Wagner grade ]3 71 (75.5%)
Diabetic foot infection 93 (98.9%)
Diabetes medication before admission
Oral hypoglycemic agent 60 (63.8%)
Insulin 10 (10.6%)
Combination therapy 4 (4.2%)
Start at hospital 20 (21.3%)
Diabetes and its complications
b
Duration of diabetes (years) 5 (021)
Admission plasma glucose (mg/dL) 325.5 (113740)
FPG (mg/dL) 220.6973.5
HbA1c (%) 11.392.8
Hypertension status 50 (53.2%)
Retinopathy
c
87 (92.6%)
Nephropathy
c
51 (54.3%)
Peripheral neuropathy
c
64 (68.1%)
Presence of PAD
c
38 (40.4%)
Presence or history of CAD
c
21 (22.3%)
Congestive heart failure
c
3 (3.2%)
Cerebrovascular disease
c
6 (6.4%)
Chronic renal failure
c
41 (43.6%)
Dialysis
c
4 (4.2%)
Data are expressed as number (%), mean9SD, or geometric mean
(95% confidence interval). DFU, diabetic foot ulcer; LEA, lower
extremity amputation; FPG, fasting plasma glucose; HbA1c,
glycated hemoglobin; PAD, peripheral arterial disease; CAD,
coronary arterial disease.
a
Case and control were adjusted for
patient’s age, sex, and nutritional status;
b
either known or
diagnosed during the course of hospitalization;
c
using the Young
et al. (30) proposed diabetic complications’ classification.
Risk factors for amputation in patients with diabetic foot ulcer
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Univariate analysis of LEA risk factors
To identify the significant risk factors for amputation, a
conditional logistic regression was performed. Studied
variables included older age, duration of diabetes, hyper-
tension status, retinopathy, neuropathic foot, presence of
PAD, wound depth, gangrene, deep abscess, osteomy-
elitis, sepsis, admission plasma glucose, FPG, HbA1c,
and lipid profile. Table 3 shows a comparison between the
cases and control group to indicate the corresponding ORs
for outcome. Significant risk factors were hypertension
Table 3. Univariate analysis of risk factors associated with lower extremity amputation
a
Non-amputation n (%) Amputation n (%) OR 95% CI p
Age ]60 years 6 (6.4%) 12 (12.7%) 2.34 0.796.89 0.122
Duration of diabetes 5 years 20 (21.3%) 26 (27.6%) 1.67 0.733.77 0.217
Prior diabetes therapy, n (%)
Not on previous treatment (reference) 11 (11.7%) 9 (9.6%) 1.00
Oral hypoglycemic agents 31 (32.9%) 29 (30.8%) 1.14 0.413.15 0.796
Insulin use (insulin alone or in combination therapy) 5 (5.3%) 9 (9.6%) 2.20 0.548.95 0.271
Admission plasma glucose ]200 mg/dL 39 (41.4%) 44 (46.8%) 3.00 0.7412.14 0.122
FPG ]126 mg/dL (mg/dL) 39 (41.4%) 46 (48.9%) 9.43 1.1378.78 0.038*
HbA1c ]8% 33 (35.1%) 45 (47.8%) 9.54 2.0344.89 0.004*
Hemoglobin 510 gr% 29 (30.8%) 27 (28.7%) 1.19 0.522.72 0.674
Leukocyte count ]1510
3
/mL 26 (27.6%) 27 (28.7%) 1.09 0.422.46 0.835
Albumin 52.5 g/dL 24 (25.5%) 28 (29.8%) 1.41 0.623.19 0.407
Serum creatinine ]1.5 g/dL 15 (15.9%) 13 (13.8%) 1.22 0.502.97 0.692
Total cholesterol ]200 mg/dL 6 (6.4%) 9 (9.5%) 1.07 0.691.67 0.736
Triglycerides ]150 mg/dL 17 (18.1%) 33 (35.1%) 2.14 1.134.04 0.019*
LDL-cholesterol ]100 mg/dL 23 (24.4%) 30 (31.9%) 1.42 0.762.62 0.277
HDL-cholesterol 540 mg/dL 39 (41.4%) 44 (46.8%) 2.67 0.7010.05 0.147
Hypertension status 19 (20.2%) 31 (32.9%) 2.85 1.236.60 0.014*
Presence of CAD
b
13 (13.8%) 8 (8.5%) 1.14 0.721.81 0.559
Diabetic retinopathy
b
42 (44.7%) 45 (47.8%) 2.50 0.4812.88 0.273
Diabetic nephropathy
b
25 (26.6%) 26 (27.6%) 1.04 0.571.90 0.879
Diabetic neuropathy
b
30 (31.9%) 34 (36.2%) 1.30 0.632.69 0.467
Diabetes with PAD
b
9 (9.6%) 29 (30.8%) 2.11 1.203.69 0.009*
Type of DFU
Pure neuropathic (reference) 25 (26.6%) 5 (5.3%) 1.00
Ischemic/neuroischemic 9 (9.6%) 29 (30.8%) 3.22 1.526.80 0.002*
Wound depth
Full thicknessdeep to fascia or tendon (reference) 31 (32.9%) 22 (23.4%) 1.00
Penetration to joint or bone 16 (17.0%) 25 (26.6%) 1.56 0.832.92 0.163
Osteomyelitis 18 (19.1%) 27 (28.7%) 2.17 0.954.96 0.065
PEDIS grade and IDSA infection severity score
PEDIS grade 12 (reference) 10 (10.6%) 4 (4.3%) 1.00
PEDIS grade 3 33 (35.1%) 35 (37.2%) 1.06 0.651.70 0.808
PEDIS grade 4 4 (4.3%) 8 (8.5%) 2.00 0.606.64 0.258
Wagner grade
c
Grade 12 (reference) 21 (22.3%) 2 (2.1%) 1.00
Grade 3 23 (24.4%) 15 (15.9%) 1.53 0.802.93 0.198
Grade 4 3 (3.2%) 30 (31.9%) 10.00 3.0532.76 B0.001*
Presence of foot necrosis or gangrene 3 (3.2%) 30 (31.9%) 25.88 6.9796.13 B0.001*
Data are expressed as number (%). LEA, lower extremity amputation; FPG, fasting plasma glucose; HbA1c, glycated hemoglobin; LDL,
low density lipoprotein; HDL, high density lipoprotein; CAD, coronary arterial disease; PAD, peripheral arterial disease; DFU, diabetic foot
ulcer; PEDIS, acronym of perfusion, extent, depth, infection and sensation.
a
Logistic regression analysis was applied, data are adjusted
for age, sex, and nutritional status;
b
using the Young et al. (30) proposed diabetic complications’ classification;
c
DFU with Wagner
classification grade 5 were excluded (see text); *denotes statistical significance (pB0.05) compared to non-amputation group.
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status (OR 2.85, 95% CI 1.236.60; p0.014), presence
of PAD (OR 6.80, 95% CI 2.6717.32; pB0.001), foot
necrosis or gangrene (OR 25.88, 95% CI 6.9796.13;
pB0.001), FPG ]126 mg/dL (OR 9.43, 95% CI 1.13
78.78; p 0.038, HbA1c ]8% (OR 9.54, 95% CI 2.03
44.89; p 0.004) and triglycerides ]150 mg/dL (OR
4.16, 95% CI 1.759.86; p 0.001). Other variables inclu-
ded in the logistic regression model were found not
significant in determining the risk of amputation.
Multivariate logistic regression model
Univariate analysis of the amputation risk versus explora-
tory variables showed that, out of 27 variables, only seven
showed a promise of influence, the latter being defined
as p 50.15 (see Table 3). The potential independent
variables included hypertension status, diabetes with
PAD, gangrene (Wagner grade 4), wound depth to bone
and joint, osteomyelitis, FPG ]126 mg/dL, HbA1c ]8%
and triglycerides ]150 mg/dL as independent variables.
Gangrenous tissue implies extensive necrosis and poor
circulation in the local tissue (36). In order to better
elucidate the risk of LEA, we decided to exclude the
variable of gangrene from further analysis.
Finally, in a stepwise manner, logistic regression analy-
sis was performed of the amputation risk vs. the remaining
seven variables simultaneously (not included gangrene),
starting with a full model and removing non-significant
variables one by one. The final result was a model with
adjusted significant predictors of undergoing an LEA.
Table 4 displays the adjusted multivariable logistic regres-
sion and, among others, the independent risk factors of
LEA are hypertension status (OR 3.67, 95% CI 1.14
11.79; p0.028), triglyceride ]150 mg/dL (OR 5.58,
95% CI 1.7417.91; p0.004), diabetes with PAD (OR
12.97, 95% CI 3.4448.88; pB0.001), and HbA1c ]8%
(OR 20.47, 95% CI 3.12134.31; p0.002). The Hosmer
Lemeshow goodness-of-fit test statistic (X
2
4.085 with 8
degree of freedom, p0.849) indicates that the model
created was appropriately fitted for the data (35). The
multivariate analysis produced a score with an AUC value
of 0.89 (95% CI 0.830.95; p B0.001) for the discrimina-
tion between those who did or did not experience an
incident LEA.
Discussion
DFU is the most frequent cause of hospitalization among
diabetic patients and LEA is the most feared consequence
of foot ulceration (2, 3, 7). The present study examined
whether or not certain baseline characteristics and labora-
tory measures can predict the risk of LEA. In Indonesia,
studies of the incidence or determination of particular risk
factors of LEA in the diabetic population are few. This
study reports the results of an extensive subset analysis of
the data collected during a period of hospitalization in the
treatment of DFU. Our references at most will examine
age, sex, and/or BMI as predictors of interest, however we
considered such variables to be included in study matching
criteria thus providing a difference from the previous
research. The samples were limited to 94 patients treated
by a diabetic foot team in a tertiary hospital in Semarang,
Indonesia and the studied populations represented a
diabetic population that constituted the highest risk of
poor outcome.
To describe the severity of DFU, we used two of the
diabetic foot classification systems: 1) Wagner grade (32),
and 2) PEDIS system as classified following IDSA-
IWGDF recommendation (34). In a Turkish cohort, Yesil
et al. (22) reported that Wagner grade (Wagner grade 4
and 5) was a strong predictor for LEAwith OR 23.95 (95%
CI 14.0440.87; p B0.001). A study from Pakistan also
reported that the frequency of amputation increased with
the higher grade (Wagner grade ]3) of ulcers (37).
According to Wagner classification, our study revealed
that 95.7% of the cases were classified as high grade lesion
(]grade 3) whereas in the control group, the number of
Table 4. Final logistic model for multivariate (adjusted) risk factors of lower extremity amputation
a
Amputation (n47)
b-coefficient Adjusted OR 95% CI p
Hypertension status 1.30 3.67 1.1411.79 0.028*
Triglycerides ]150 mg/dL 1.72 5.58 1.7417.91 0.004*
FPG ]126 mg/dL 2.16 8.67 0.74101.11 0.085
Diabetes with PAD 2.56 12.97 3.4448.88 B0.001*
HbA1c ]8% 3.01 20.47 3.12134.31 0.002*
Area under the ROC curve0.89; HosmerLemeshow goodness-of-fit test: X
2
4.085, p0.849. In the multivariate model, the following
variables were added as potential independent variables: patient’s age ]60 years, hypertension status, neuropathic foot, diabetes with
PAD, admission plasma glucose ]200 mg/dL, FPG ]126 mg/dL, HbA1c ]8%, triglycerides ]150 mg/dL, wound depth and
osteomyelitis. OR, odds ratio; CI, confidence interval; FPG, fasting plasma glucose; HbA1c, glycated hemoglobin; PAD, peripheral arterial
disease.
a
Backward stepwise conditional logistic regression model was applied; *denotes statistical significance (pB0.05) compared to
non-amputation group.
Risk factors for amputation in patients with diabetic foot ulcer
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patients with high Wagner grade was 51.1%. By condi-
tional logistic regression, we obtained a 10-fold increased
risk of amputation when DFU severity at admission was at
least Wagner grade 4 when compared to grade 1 and grade 2.
We also found that DFU that penetrated to bone was
not merely a risk factor but the presence of gangrene
became a very strong reason for an LEA (OR 25.88, 95%
CI 6.9796.13; pB0.001). The prevalence of overall pa-
tients with foot necrosis or gangrene was 35.1% (we
excluded Wagner grade 5, see Methods section). Our
hospital was considered as the main referral medical
center in Central Java District, thus hospitalized patients
contained complexities and more advanced DFU with
an increased risk of extensive surgical management. This
fact becomes a relatively common scenario in developing
countries while there was a sequential timeline of patients
before referred to the hospital and brings consider-
able delay for optimal management when an amputation
surgery was inevitable (35).
After accounting for differences in the stage of presenta-
tion, we addressed the role of PAD on this matter regarding
LEA risk in patients with DFU. PAD was identified by
different studies as an independent risk factor for LEA; it is
a point of almost universal agreement among studies (11,
12, 14, 18, 20).The Eurodiale study (38) has confirmedwhen
stratifying patients according to the presence or absence of
PAD, significantly fewer ulcers with PAD were healed than
those without PAD (69 vs. 84%, respectively). In our study,
the prevalence of PAD is about 40.4% of all studied
population. There was also a significantly higher preva-
lence of PAD in the case subjects. As many as 61.7% of
patients from the LEA group had various degrees of PAD
compared to 9.6% on the control group (p0.009). PAD
was associated with LEA because of impairment in wound
healing due to inadequate circulation and its presence
(PAD that did not present the possibility of revasculariza-
tion) led to a significantly higher rate of LEA (OR 6.80;
95% CI 2.6717.32; pB0.001). The subsets of patientswith
most likelihood to present with LEA were those with
neuroischemic ulcer (OR 3.22, 95% CI 1.526.80; p
0.002) compared to only neuropathic ulcer, showing that
combined risk factors put patients at a significantly higher
risk. Because we did not differentiate the minor from major
LEA, an interesting report by Calle-Pasqual et al. (39)
shows that 100% of the major amputations, whereas a
lower percentage (62%) of minor amputations in their
population-based series were associated with PAD. Reiber
et al. (20) also reported that the presence of PAD as
indicated by Doppler vascular studies (OR 4.3 for mild to
moderate PAD and OR 55.8 for severe PAD) was the most
powerful predictor of amputation in diabetic subjects.
Another finding in our sampled population was the
high prevalence (68.1%) of peripheral diabetic neuropathy.
This finding was common in the countries of develop-
ing economics, where ischemic disease accounts for only
2030% of cases (18, 40). In contrast, the nations of Western
Europe and the USA have higher prevalence of PAD
(usually around 50% or more) and reporting a lesser
prevalence of peripheral neuropathy (38, 39). Ethnic
differences in PAD and diabetes-related microangiopathy
rates have been observed (41, 42). The vast majority of our
patients were Javanese and that might be able to partly
explain the relative difference between PAD and neuro-
pathy prevalence in this study compared to other scientific
literature. Our results signify an important pathway of foot
ulceration through peripheral neuropathy. But contrary to
the expectation, our study revealed that diabetic peripheral
neuropathy was found to have no independent effect on the
final outcome as determined by statistical analysis. As
shown in Table 3, patients with peripheral neuropathy and
PAD (i.e. neuroischemic ulcer-type) were more likely to
undergo LEA but neuropathy alone was not indepen-
dently associated with LEA. It has been suggested that
neuropathy may precipitate an ulcer through decreased
foot protective sensation, however it was the PAD that
inhibited the ulcer from healing (1, 38, 43). In our study
population, diagnosis of diabetic retinopathy and nephro-
pathy did not prove to be significant and independent risk
factors for LEA. The high prevalence of diabetes-related
microangiopathy may indicate that the patients in both
case and control subjects have already experienced an
advanced diabetes stage altogether with their DFU
occurrence in the hospital.
The most important finding in our study was that poor
glycemic control had a major role in the development of
LEA. In the results of our study, baseline glycemic control
(median plasma glucose 325.5 mg/dL (range 113740),
mean FPG 220.6973.5 mg/dL, and mean HbA1c
11.392.8%, see Table 2) show that the diabetics in our
studied population was poorly controlled. HbA1c above
8% was a significant risk factor for LEA (OR 20.47, 95%
CI 3.44134.31; p0.002) whereas admission blood
glucose was not included in the final model, and FPG
did not meet statistical significance in the final multi-
variate analysis. The role of chronic hyperglycemia as
indicated by high HbA1c level as a marker of LEA incident
is similar to several other studies, notably those reported
by Moss et al. (10), Miyajima et al. from Japan (17), and
Imran et al. (37). In contrast to admission plasma glucose,
FPG, or post-prandial blood glucose; the level of HbA1c is
directly related to the average glucose concentration over
the life span of the hemoglobin (44). The strong associa-
tion of HbA1c with LEA could reflect a greater pathogenic
role of chronic hyperglycemia probably via neuropathy,
autonomic dysfunction, PAD, and susceptibility to infec-
tion (44, 45). The United Kingdom Prospective Diabetes
Study (46) reported that the hazard ratio of death from
amputation declines 43% when HbA1c declines by 1%.
The Steno-2 study (47) has shown that an intensified
multifactorial intervention including tight glucose control
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reduces the risk of vascular complication by half, and
significantly lowers the amputation rate compared to
standard treatment for patients with type 2 diabetes. The
meta-analysis adds to the accumulating data on hypergly-
cemia as an independent risk factor for LEAs (45).
Because metabolic control in diabetic patients tends to
deteriorate linearly with time after the diagnosis, the
exposure to the harmful effects of hyperglycemia will
increase with the longer duration of diabetes (11, 46). In a
study from Finland by Lehto et al. (11), the duration of
diabetes was related to the risk of LEA independently of
the degree of hyperglycemia. However, from Table 3 of our
study, we can conclude that as many as 27.6% of cases
compared to 21.3% of control had diabetes for more than
5 years (p0.217) and the clinical duration of diabetes was
not related to the risk of amputation. Our finding was
similar to many other studies that claimed the duration of
diabetes is not a baseline factor that predicts amputation
(17, 19, 22). Reiber et al. (20) and Adler et al. (45) also
reported the non-differences in the risk of LEA by the
duration of diabetes but the risk can be explained better by
the level of glycemia. However, the clinical duration of
diabetes may contain an error because the initial diagnosis
does not always coincide with the onset of the metabolic
disease. Arguably, the diabetes duration calculated in this
way is shorter than the real duration of diabetes (4).
Hypertension also contributes to the development and
progression of chronic diabetes complications and it is
considered as an established risk factor for atherosclerosis
(30). The data concerning the importance of blood
pressure as a predictor of LEA are somehow conflicting.
In American Indians, systolic blood pressure was found to
be an important predictor of LEA (16). Other previous
cross-sectional and prospective studies also have shown an
association between amputation with higher blood pres-
sure parameter (15, 19). On the contrary, a population
study conducted by Lehto et al. (11) reported that
hypertension was not found to be a significant predictor
for LEA incident. In our study, there were significantly
more recorded diagnoses of hypertension in case subjects
compared to control group (32.9 vs. 20.2%, p0.013) and
we found that hypertension status was a major risk factor
for LEA (OR 3.43; 95% CI 1.0710.94, p0.037). Our
finding was in accordance with Wisconsin Epidemiologic
Study of Diabetic Retinopathy which shows that blood
pressure and HbA1c were related to amputation risk but
that nephropathy and retinopathy were at most only
weakly correlated (10). Direct comparison of the role of
hypertension as a risk factor for LEA between the studies is
difficult because of diverse methods of defining hyperten-
sion, different demographics, and sample population.
Several lipoprotein abnormalities have been reported to
be more prevalent among diabetic than non-diabetic
persons (2830). Only a few studies have been published
regarding the effect of abnormalities in lipids and lipo-
proteins on the risk of amputation in DFU. The recent
study by Zubair et al. (19) reported that the levels of fasting
triglyceride (150 mg/dL), cholesterol (150 mg/dL),
LDL-cholesterol (100 mg/dL), and HDL-cholesterol
(B40 mg/dL) were associated with the risk of amputation.
Our observation regarding plasma lipoproteins have
demonstrated that of all the elements considered, only
hypertriglyceridemia predicts LEA (OR 5.87, 95% CI
1.8418.97; p 0.003) whereas the other fractions do not
seem to be associated with amputation. Another study by
Lacle et al. (13) from Costa Rica and Chaturvedi et al. (41)
from The WHO Multinational Study also failed to
demonstrate that serum cholesterol, LDL-cholesterol,
and HDL-cholesterol are significant risk factors for
LEA. Hypertriglyceridemia has shown to be an indepen-
dent stepwise risk factor in a cohort of 28,700 diabetic
patients from Distance study (48). Increased plasma
triglycerides were also reported by Lee et al. to be signi-
ficant risk factors for LEA in American Indian women
(15). However, there was no clear explanation about what
extent and if there was a causative relationship or if
triglycerides just merely serve as a risk marker (15, 48).
Clearly, further studies are needed to ascertain the role of
hypertriglyceridemia in these diabetic sequelae.
Benotmane et al. (40) reported that length of stay was
increased in patients with high grade of Wagner classifi-
cation. The length of hospitalization was 15.5 days in our
study. In other studies, the length ranged from 20 to 40
days (40, 49). Currie et al. (50) studied the patients with
PAD, infection, neuropathy, and ulceration and reported
that diabetics had twice longer length of stay as
compared with non-diabetic patients. History of previous
ulceration and amputation in either foot can also predict
amputation in previous reports (10, 1214, 33). Such
previous history (previous ulceration or amputation) was
not an independent risk factor according to our analysis.
The less obvious risk factors such as sex, older age, and
lower BMI were not prominent because of the study
matching criteria. The other risk factors that were not
addressed in this study were smoking history and ulcer
size. Although it was included in the study protocol, it
was not feasible because such information was not found
in most of our charts.
Diabetic foot problems develop on the basis of micro- or
macroangiopathy and can present with infection (1, 31).
Diabetic foot infections can threaten a limb when there is
osteomyelitis and/or sepsis (34). In our study, infectious
events occurred in nearly all lesions (98.8%). If compared
to other studies, the prevalence of infection in our study
was higher which may be related to uncontrolled hyper-
glycemia, presence of PAD, and cultural differences in foot
care. More severe infection (PEDIS grade 3 and 4) is
associated with higher rates of LEA than milder one (45.7
vs. 39.3%, p0.138). If compared to mild infection
(PEDIS grade 1 and grade 2) as reference categories,
Risk factors for amputation in patients with diabetic foot ulcer
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obviously the more severe infection only shows a step-up
increase of OR which was not statistically significant.
Previous studies agree that foot infection is a risk factor for
diabetic foot amputation (10, 21, 51), however our data did
not reveal a strong association. This substantiates that a
septic foot does not inevitably lead to LEA and may
explain the role of severe infection as dependent rather
than independent of risk factors. In support of this
observation was a previous study by Bamberger et al. in
1987 (52). Their group reported the success in eradicating
osteomyelitis in 27 out of 52 patients (53%) by conservative
approach and suggested a good outcome without the need
for an ablative surgical procedure in the absence of
extensive necrosis or gangrene. A more recent cohort
study (n58) by Yadlapalli et al. (53) also support in
attempting a treatment based on local care and potent
antibiotic regimens.
Overall, DFU and amputation could be considered as
the marker of advanced stage of diabetes. Some authors
hypothesized that DFU could be per se an independent
predictive variable of LEA as well as mortality (14). Many
factors influence the decision of whether or not an LEA
should be performed on a patient with DFU, besides the
ulcer severity as determined by high Wagner grade. The
predictive estimate of our model was 0.89 (95% CI 0.83
0.95; p B0.001); it was similar to that of a model suggested
by Martins-Mendes et al., 0.81 (95% CI 0.740.87; p
0.001) from Portugal (14) and a study by Lipsky et al., 0.72
(95% CI 0.670.77; pB0.001) in diabetic foot infection
(54). Martins-Mendes et al. (14) suggested the following
risk factors for LEA: previous DFU, PAD complication
history, neuropathy, and nephropathy. Lipsky et al. (54)
reported that LEAs were higher for patients with surgical
site infection, vasculopathy, amputation history, and high
leukocyte count. We added a few more variables to this
suggested model and identified a typology of risk for LEA
in DFU patients with an average HbA1c ]8%, along with
the presence of PAD, hypertriglyceridemia, and hyperten-
sion. Accordingly, diabetic patients with foot ulcers with
the above-mentioned profile should be considered to be at
high risk of LEA and signal the need for close monitoring
by health care professions. The variations in the extent and
ranking of risk factors for the development of diabetic
foot LEA between the present results and other research
are probably due to differences in study settings and
population selection.
Study limitations
This study has several limitations. First, missing data were
inevitable because our analysis was a retrospective study.
Hospital discharge database as a source of our information
was administrative in nature and not primarily intended
for research purposes, consequently, many variables that
affected the outcomes were not recorded or considered.
This included type of off-loading and description of foot
deformities. The degree of blood pressure control, lipid
control, and previous foot care procedures prior to
hospitalization was also difficult to estimate. Second, the
specific type and duration of antibiotics for patients with
infection were not well documented. Third, we did not
address the severity of PAD in distinct gradation and this
might have affected the final outcome. Fourth, the data
used in this study was generated from one hospital,
limiting its generalizability to other hospitals. Our studied
population was mainly Javanese, therefore all our results
may not apply directly to other racial or ethnic groups. This
analysis, despite having limitations for a developing
country with limited data on economics and a lack of
continuous longitudinal data on LEA, could be justified by
the fact that the studied risk factors can easily be assessed
and are potentially modifiable during clinical practices.
The present study, to our knowledge, is the first study
sharing the experience of a DFU management in Sema-
rang for the evaluation of risk factors for LEA.
Conclusions
In the results of our analysis, poor glycemic control, the
presence of PAD, hypertriglyceridemia, and hypertension
status were independent risk factors for LEA. Short of
prevention of DFU itself, this study indirectly implies that
early intervention before critical DFU has developed
might help to prevent diabetes-related LEA. However,
we believe that not all of these DFU can be prevented and
still, clinicians will face patients in the hospital with DFU
in advanced stages as ours. Diabetic patients with inade-
quately controlled blood glucose levels are at highest
significant risk for serious complications affecting their
lower limbs. Strict control of diabetes, which is the primary
disease, is first of all required for the risk reduction. For
the PAD, active investigation of each patient is necessary
to assess the possibility of revascularization and the
probability of wound healing. At the same time, this study
indicates that triglyceride and hypertension control should
not preclude the pursuit of limb conserving treatment
options and both may be an important additional primary
prevention effort. We suggest that prospective studies and
multicenter designs involving more detailed vascular risk
factors should be undertaken in the future for further
conclusions.
Conflict of interest and funding
The authors have no conflict of interest to declare in
relation to the content of this article.
References
1. Djokomoeljanto R. Tinjauan umum tentang kaki diabetes.
In: Djokomoeljanto R, Darmono, Suhartono T, eds. Kaki
diabetik: Patogenesis dan penatalaksanaan. Semarang: Dipo-
negoro University; 1997, pp. 110.
Tjokorda Gde Dalem Pemayun et al.
10
(page number not for citation purpose)
Citation: Diabetic Foot & Ankle 2015, 6: 29629 - http://dx.doi.org/10.3402/dfa.v6.29629
2. Reiber GE. The epidemiology of diabetic foot problems.
Diabetic Med 1996; 13: 611.
3. Thewjitcharoen Y, Krittiyawong S, Porramatikul S, Parksook
W, Chatapat L, Watchareejirachot O, et al. Outcomes of
hospitalized diabetic foot patients in a multi-disciplinary team
setting: Thailand’s experience. J Clin Transl Endocrinol 2014; 1:
18791.
4. van Houtum WH. Diabetes related lower extremity ampu-
tations. Master dissertation, Vrije University, Amsterdam
The Netherland, 1998.
5. Abbas ZG. Reducing diabetic limb amputations in developing
countries. Expert Rev Endocrinol Metab 2015; 10: 42534.
6. Unwin N, Mackintosh J, LaPorte R, Chang YF, Renzie R, on
behalf of The Global Lower Extremity Study Group. Epide-
miology of lower extremity amputation in centres in Europe,
North America and East Asia. Br J Surg 2000; 87: 32837.
7. Dillingham TR, Pezzin LE, MacKenzie EJ. Limb amputation
and limb deficiency: epidemiology and recent trends in the
United States. South Med J 2002; 95: 87583.
8. Pecoraro RE, Reiber GE, Burgess EM. Pathways to diabetic
limb amputation: basis for prevention. Diabetes Care 1990; 13:
51321.
9. Bowker JH. Minor and major lower limb amputations and
disarticulations in patients with diabetes mellitus. In: Bowker
JH, Pfeifer MA, eds. Levin and O’Neal’s: the diabetic foot.
Philadelphia, PA: Mosby Elsevier; 2008, pp. 40328.
10. Moss SE, Klein R, Klein BEK. The prevalence and incidence of
lower extremity amputation in a diabetic population. Arch
Intern Med 1992; 152: 61016.
11. Lehto S, Ronnemaa T, Pyorala K, Laakso M. Risk factors pre-
dicting lower extremity amputation in patients with NIDDM.
Diabetes Care 1996; 19: 60712.
12. Shojaiefard A, Khorgami Z, Larijani B. Independent risk
factors for amputation in diabetic foot. Int J Diabetes Dev
Ctries 2008; 28: 327.
13. Lacle A, Valero-Juan LF. Diabetes-related lower-extremity
amputation incidence and risk factors: a prospective seven-year
study in Costa Rica. Rev Panam Salud Publica 2012; 32: 1928.
14. Martins-Mendes D, Monteiro-Soares M, Boyko EJ, Ribeiro M,
Barata P, Lima J, et al. The independent contribution of diabetic
foot ulcer on lower extremity amputation and mortality risk.
J Diabetes Complications 2014; 28: 6328.
15. Lee JS, Lu ML, Lee VS, Russel D, Bahr C, Lee ET. Lower-
extremity amputation: incidence, risk factors and mortality
in the Oklahoma Indian Diabetes Study. Diabetes 1993; 42:
87682.
16. Resnick HE, Carter EA, Sosenko JM, Henly SJ, Fabsitz RR,
Ness FK, et al. Incidence of lower-extremity amputation in
American Indians: the Strong Heart Study. Diabetes Care 2004;
27: 188591.
17. Miyajima S, Shirai A, Yamamoto S, Okada N, Matsushita T.
Risk factors for major limb amputations in diabetic foot
gangrene patients. Diabetes Res Clin Pract 2006; 71: 2729.
18. Aziz Z, Lin WK, Nather A, Huak CY. Predictive factors for
lower extremity amputations in diabetic foot infections. Diabetic
Foot Ankle 2011; 2. doi: http://dx.doi.org/10.3402/dfa.v2i0.7463
19. Zubair M, Malik A, Ahmad J. Incidence, risk factors for
amputation among patients with diabetic foot ulcer in a North
Indian tertiary care hospital. Foot 2012; 22: 2430.
20. Reiber GE, Pecoraro RE, Koepsell TD. Risk factors for
amputation in patients with diabetes mellitus: a case-control
study. Ann Intern Med 1992; 117: 97105.
21. Carlson T, Reed JF. A case-control study of the risk factors for
toe amputation in a diabetic population. Int J Lower Ext
Wounds 2003; 2: 1921.
22. Yesil S, Akinci B, Yener S, Bayraktar F, Karabay O, Havitcioglu
H, et al. Predictors of amputation in diabetics with foot ulcer:
single center experienced in a large Turkish cohort. Hormones
2009; 8: 28695.
23. van Battum P, Schaper N, Pompers L, Apeqvist J, Jude E,
Piaggesi A, et al. Differences in minor amputation rate in
diabetic foot disease throughout Europe are in part explained by
differences in disease severity at presentation. Diabet Med 2011;
28: 199205.
24. Breslow NE. Case-control studies. In: Ahrens W, Pigeot I, eds.
Handbook of epidemiology. Berlin: Springer; 2005, pp. 287
319.
25. Decroli E, Karimi J, Manaf A, Syahbuddin S. Profil ulkus
diabetik pada penderita rawat inap di bagian penyakit dalam
RSUP Dr. M. Djamil Padang. Maj Kedokt Indon 2008; 58: 37.
26. Madiyono B, Moeslichan S, Sastroasmoro S, Budiman I,
Purwanto SH. Perkiraan besar sampel. In: Sastroasmoro S,
Ismael S, eds. Dasar-dasar metodologi penelitian klinis.
3rd ed. Jakarta: Sagung Seto; 2007, pp. 30231.
27. Wacholder S, Silverman DT, McLaughlin JK, Mandel JS.
Selection of controls in case-control studies. III. Design options.
Am J Epidemiol 1992; 135: 104250.
28. National Cholesterol Education Program. ATP III guidelines at-a-
glance quick desk reference. Available from: http://www.nhlbi.nih.
gov/files/docs/guidelines/atglance.pdf [cited 27 April 2015].
29. Pengurus Besar Perkumpulan Endokrinologi Indonesia.
Konsensus pengelolaan dan pencegahan diabetes mellitus tipe
2 di Indonesia. Jakarta: Pengurus Besar Perkumpulan Endok-
rinologi Indonesia; 2006.
30. Young BA, Lin E, Von Korff M, Simon G, Ciechanowski P,
Ludman EJ, et al. Diabetes complication severity index and risk
of mortality, hospitalization and healthcare utilization. Am J
Manage Care 2008; 14: 1524.
31. Dalem Pemayun TG. Patofisiologi kaki diabetika. Annual
Endocrinology Scientific Meeting XII Joglosemar 2011. Inte-
grating basic science and clinical practice in endocrinology for
better quality care, Jogjakarta, 78 May 2011, pp. 18892.
32. Wagner FW Jr. The diabetic foot. Orthopedics 1987; 10: 16372.
33. Abbott CA, Carrington AL, Ashe H, Bath S, Every LC,
Griffiths J, et al. The North-West Diabetes Foot Care Study:
incidence of, and risk factors for, new diabetic foot ulceration
in a community-based patients cohort. Diabet Med 2002; 19:
37784.
34. Schaper NC. Diabetic foot ulcer classification system for
research purposes: a progress report on criteria for including
patients in research studies. Diabetes Metab Res Rev 2004; 20:
S905.
35. Hosmer DW, Lemeshow S. Applied logistic regression, 2nd ed.
Hoboken, NJ: Wiley; 2000.
36. Edmonds ME, Foster AVM, Sanders LJ. Stage 5: The necrotic
foot. In: Edmonds ME, Foster AVM, Sanders LJ, eds. Prac-
tical manual of diabetic foot care. 2nd ed. Oxford: Blackwell;
2008, pp. 181214.
37. Imran S, Ali R, Mahboob G. Frequency of lower extremity
amputation in diabetics with reference to glycemic control and
Wagner’s grade. J Coll Phys Surg Pak 2006; 16: 1247.
38. Pompers L, Schaper N, Apelqvist J, Edmonds M, Jude E,
Mauricio D, et al. Prediction of outcome in individuals with
diabetic foot ulcers: focus on the differences between individuals
with and without peripheral arterial disease. The EURODIALE
Study. Diabetologia 2008; 51: 74755.
39. Calle-Pasqual AL, Garcia-Torre N, Moraga I, Diaz JA, Duran
A, Monux G, et al. Epidemiology of nontraumatic lower-
extremity amputation in area 7, Madrid, between 1989 and
1999: a population-based study. Diabetes Care 2001; 24:
16869.
Risk factors for amputation in patients with diabetic foot ulcer
Citation: Diabetic Foot & Ankle 2015, 6: 29629 - http://dx.doi.org/10.3402/dfa.v6.29629 11
(page number not for citation purpose)
40. Benotmane A, Mohammedi F, Ayad F, Kadi K, Medjbeur S,
Azzouz A. Management of diabetic foot lesions in hospital:
costs and benefit. Diabetes Metab 2001; 27: 68894.
41. Chaturvedi N, Stevens LK, Fuller JH, Lee ET, Lu M. Risk
factors, ethnic differences and mortality associated with lower-
extremity gangrene and amputation in diabetes. The WHO
multinational study of vascular disease in diabetes. Diabetologia
2001; 44: S6571.
42. Chaturvedi N, Abbott CA, Whalley A, Widdows P, Leggetter SY,
Boulton AJ. A review of ethnic differences in risk factors for
diabetic foot ulcers. Podiatry Today 2002, p. 15. Available from:
http://www.podiatrytoday.com/article/257 [cited 21 October 2015].
43. Widiastuti MI. Peran neuropati pada patogenesis kaki diabetika.
In: Suhartono T, Dalem Pemayun TG, Nugroho KH, eds. Kursus
manajemen holistik ‘‘Kaki Diabetika’’. Semarang: Diponegoro
University Press; 2007, pp. 1934.
44. Marcovecchio ML, Lucantoni M, Chiarelli F. Role of chronic
and acute hyperglycemia in the development of diabetes
complications. Diabetes Technol Ther 2011; 13: 38994.
45. Adler AI, Erqou S, Lima TA, Robinson AH. Association
between glycated hemoglobin and the risk of lower extremity
amputation in patients with diabetes mellitus review and
meta-analysis. Diabetologia 2010; 53: 8409.
46. Stratton IM, Adler AI, Neil HA, Matthews DR, Manley SE,
Cull CA, et al. Association of glycemia with macrovascular and
microvascular complications of type 2 diabetes (UKPDS 35):
prospective observational study. BMJ 2000; 321: 40512.
47. Gaede P, Lund-Andersen H, Parving HH, Pedersen O. Effect of
a multifactorial intervention on mortality in type 2 diabetes. N
Engl J Med 2008; 358: 58091.
48. Callaghan BC, Feldman E, Liu J, Kerber K, Pop-Busui R,
Moffet H, et al. Triglycerides and amputation risk in patients
with diabetes: ten-year follow-up in the DISTANCE study.
Diabetes Care 2011; 34: 63540.
49. Lawrence SM, Wraight PR, Campbell DA, Colman PG.
Assessment and management of inpatients with acute diabetes-
related foot complications: room for improvement. Intern Med
J 2004; 34: 22933.
50. Currie CJ, Morgan CL, Peters JR. The epidemiology and cost
of inpatient are for peripheral vascular disease, infection, neuro-
pathy and ulceration in diabetes. Diabetes Care 1998; 21: 428.
51. Treece KA, MacFarlane RM, Pound N, Game FL, Jeffcoate
WJ. Validation of a system of foot ulcer classification in diabetes
mellitus. Diabet Med 2004; 21: 98791.
52. Bamberger DM, Daus GP, Gerding DN. Osteomyelitis in the
feet of diabetic patients: long-term results, prognostic factors,
and the role of antimictrobial and surgical therapy. Am J Med
1987; 83: 65360.
53. Yadlapalli NG, Vaishnav A, Sheehan P. Conservative manage-
ment of diabetic foot ulcers complicated by osteomyelitis.
Wounds 2002; 14: 315.
54. Lipsky BA, Weigelt JA, Sun X, Johannes RS, Derby KG, Tabak
YP. Developing and validating a risk score for lower-extremity
amputation in patients hospitalized for a diabetic foot infection.
Diabetes Care 2011; 34: 1695700.
Tjokorda Gde Dalem Pemayun et al.
12
(page number not for citation purpose)
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