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Journal of Back and Musculoskeletal Rehabilitation 28 (2015) 433–441 433
DOI 10.3233/BMR-140537
IOS Press
Sleep quality in patients with chronic low
back pain: A cross-sectional study assesing its
relations with pain, functional status and
quality of life
Melek Sezgina,∗, Ebru Zeliha Hasanefendio˘
glub, Mehmet Ali Sungurc, Nurgül Arıncı Incela,
Özlem Bölgen Çimena,ArzuKanık
dand Gün¸sah ¸Sahina
aDepartment of Physical Medicine and Rehabilitation, Medical Faculty, Mersin University, Mersin, Turkey
bDepartment of Physical Medicine and Rehabilitation, Mus State Hospital, Mu¸s, Turkey
cDepartment of Biostatistics and Medical Informatics, Medical Faculty, Düzce University, Düzce, Turkey
dDepartment of Biostatistics and Medical Informatics, Medical Faculty, Mersin University, Mersin, Turkey
Abstract.
OBJECTIVE: The aim of this study was to investigate sleep quality in patients with chronic low back pain (CLBP) and its
relationship with pain, functional status, and health-related quality of life (HRQOL).
METHODS: Two hundred patients with CLBP aged 20–78 years (mean: 50.2 years) and 200 sex- and age-matched pain-free
healthy controls (HCs) aged 21–73 years (mean: 49.7 years) were included in this study. After lumbar region examination, in
patients, pain was evaluated with the Short Form-McGill Pain Questionnaire (SF-MPQ), functional capacity with the Functional
Rating Index (FRI), and health-related quality of life with the Short Form-36 (SF-36). The Pittsburgh Sleep Quality Index (PSQI)
was used to evaluate sleep quality of both groups.
The sleep quality was compared between the patients and HCs. In patients with CLBP, its relations with pain, functional status
and HRQOL were also investigated.
RESULTS: The patients had significantly higher total scores (8.1 ±4.3, 4.6 ±3.4, P<0.001, respectively) and subscale scores
(P<0.001) for PSQI compared to HCs. The groups were only similar in use of sleeping medication (P>0.05) Among the
patients, sleep quality was worse in women, in the patients with complaints more than 11 years, in the patients with low back and
two leg pain (P<0.05). Mean scores of the FRI, SF-MPQ, and visual analog scale in the patients were 8.5 ±3.0, 16.7 ±8.0,
6.9 ±1.2, respectively. The PSQI total scores of patients were positively related with both SF-MPQ and FRI scores (P<0.001).
Also, there were negative relationships between the physical component summary score of the SF-36 and all subscale scores of
the PSQI, without sleep duration of PSQI (P<0.001).
CONCLUSION: The sleep quality of patients with CLBP was worse compared to HCs, and there were positive relations between
the sleep quality with pain and functional status. Also, the poor sleep quality had negative effect on the physical component of
quality of life.
Keywords: Chronic low back pain, functional status, health-related quality of life, sleep quality
∗Corresponding author: Melek Sezgin, Department of Physical
Medicine and Rehabilitation, Medical Faculty, Mersin University,
Mersin, Turkey. Tel.: +90 324 2410000/2558, +90 542 5287800;
E-mail: mksezgin@gmail.com.
1. Introduction
Low back pain (LBP) is a major health and socioe-
conomic problem in industrialized countries. It is usu-
ally defined as pain localized below the line of the 12th
rib and above the inferior gluteal folds, with or with-
out leg pain. It is estimated that 70 to 85 percent of
ISSN 1053-8127/15/$35.00 c
2015 – IOS Press and the authors. All rights reserved
434 M. Sezgin et al. / Sleep quality in patients with CLBP
all people have back pain at some time in life. The
annual prevalence of back pain ranges from 15 to 45
percent [1,2]. Overall, 60 to 70 percent of patients re-
cover quickly and without residual functional loss by
six weeks, but approximately 10 percent go on to de-
velop chronic persistent or reccurrent pain [2].
Chronic pain and sleep disturbances have a recip-
rocal relation and are frequently encountered together.
Sleeping less than eight hours each night may lead to
sleep deprivation ,which may cause impairment in long
term sleep patterns [3–5]. Sleep deprivation and poor
sleep quality may decrease pain threshold in healthy
subjects and the mental capacity to manage pain. De-
crease in slow wave sleep may account for this situa-
tion [6,7]. In addition, chronic pain may lead to dete-
rioration of sleep. Sleep disorder is a common prob-
lem in 50 to 70 percent of patients with chronic non
malignant pain [8–12]. Although difficulties in initiat-
ing and maintaining sleep are common within the gen-
eral population, difficulty falling asleep and remain-
ing asleep, early awakening, and interrupted sleep in-
cluding sleep disturbances have been documented in
chronic pain situations [3,13]. Sleep disorders, which
emerge due to chronic pain, may lead the subject to ex-
perience some problems such as a weakening memory,
difficulties carrying out simple tasks, and stress in daily
life. It is obvious that all of them will exert negative
impact on quality of life [14,15].
The Pittsburgh Sleep Quality Index (PSQI) is the
most commonly used standardized questionnaire for
the comprehensive assessment of sleep quality. It al-
lows for the determination of patterns of sleep dysfunc-
tion over the prior month through the assessment of
qualitative and quantitative data. Its validity was cor-
roborated by discrimination from controls and through
positive correlations with polysomnography [16,17].
Chronic low back pain is one of the most com-
mon chronic pain states. Understanding the severity
and nature of sleep disturbance in these patients will
constitute an integral part of treatment. The first aim
of the present study was to investigate sleep quality
in patients with CLBP. The secondary objective was
to investigate the relations between sleep quality and
pain, functional status and health-related quality of life
(HRQOL).
2. Material and method
2.1. Patient selection
The required minimum sample size with power anal-
ysis calculation (Type II error 0.01 and Type I error
0.05) was determined as 187 subjects in each group.
Two hundred patients (100 male and 100 female) who
were admitted to outpatient clinic of the Mersin Uni-
versity Medical Faculty of Physical Therapy and Re-
habilitation Department and diagnosed with CLBP
were included in this study. In addition, sex and age-
matched, 200 (100 male and 100 female) pain-free
healthy controls (HCs) were included. HCs group was
composed of hospital staff, friends, and family circles.
Inclusion criteria to the patient group were presence
of mechanical LBP for longer than three months, age
18 years or older, intact cognitive functions, and liter-
acy.Criteria of inclusion to control group were absence
of LBP at least three months prior to the initiation of
the study, absence of acute or chronic pain complaint
(musculoskeletal system, headache), age 18 or older,
intact cognitive functions, and literacy.
Exclusion criteria were the presence of inflamma-
tory LBP (such as spondyloarthropathy), fibromyal-
gia, postoperative LBP, compression fractures (such
as osteoporosis), infections (discitis, spondylodisci-
tis, sacroileitis), LBP due to malignity (primary or
metastatic tumors), primary insomnia, characterized
depressive state and use of medications for depres-
sion (because reporting of sleep difficulties may be ob-
scured if study population are taking antidepressants
and sedative/hypnotics), pregnant women and nursing
mothers and concomitant disease apart from hyperten-
sion, hypercholesterolemia, and noninsulin-dependent
diabetes.
A cross-sectional study was planned in accordance
with the Helsinki declaration and ethical approval for
the study was obtained from Ethics Committee of
Mersin University. All subjects were informed about
the study and informed consent was obtained from
the individuals who agreed to participate. The patients
and HCs were evaluated with regard to age, sex, body
weight, height, body mass index (BMI), education sta-
tus, and occupation. In addition, patients were evalu-
ated for complaints and the duration of pain. In the pa-
tient group, to evaluate pain the Short Form McGill
Pain Questionnaire (SF-MPQ), to evaluate functional
status the Functional Rating Index (FRI), and to assess
quality of life the Short Form-36 (SF-36) was used.
The sleep quality of both the patients with CLBP and
HCs was evaluated with the Pittsburgh Sleep Quality
Index (PSQI). All of two hundred patients and 200
HCs, completed the study. There was no missing data
in files of all subjects.
M. Sezgin et al. / Sleep quality in patients with CLBP 435
2.2. Pittsburgh Sleep Quality Index
The reliability and validity study of Turkish ver-
sion of the index which was developed by Buysse et
al. [16] was conducted by Agargün et al. [18]. The
PSQI is a self-reported index that assesses sleep qual-
ity during the previous month. It has 19 items, each of
which is scored equally between 0 and 3. The index
contains seven subscales evaluating subjective sleep
quality, sleep latency, sleep duration, habitual sleep ef-
ficiency, sleep disturbances, use of sleeping medica-
tions, and daytime dysfunction. The seven component
scores are then summed to yield a global PSQI score,
which has a range of 0 to 21; higher scores indicate
worse sleep quality.
2.3. Short Form McGill Pain Questionnary
It was developed in 1987 by Melzack. The reliabil-
ity and validity of Turkish version has been shown and
it is used commonly in the measurement of pain. This
questionnaire provides information on the sensory, af-
fective, and intensity component of the pain sensa-
tion. The SF-MPQ consists of 15 descriptive adjectives
for the pain sensation (11 sensory and four affective),
which are self-evaluated by the patient according to
their intensity level on a point rating scale (0 =none,
1=mild, 2 =moderate, 3 =severe). The sensory and
affective scores are calculated by adding the sensory
and affective intensity values.The total score is the sum
of the intensity values. In addition, this questionnaire
includes pain intensity measures shown by visual ana-
log scale (VAS) and the evaluative total pain intensity
(ETPI) index with Likert’s scale (1 =none, 2 =mild,
3=moderate, 4 =severe, 5 =quite severe) [19,20].
2.4. Functional Rating Index
The index includes 10 items quantitatively measur-
ing the function and pain of the spinal musculoskeletal
system. The reliability and validity of the Turkish ver-
sion was proven by Bayar et al. Of these, eight refer
to activities of daily living that might be adversely af-
fected by a spinal condition, and two refer to two dif-
ferent attributes of pain. For each item, scale with five
choices is used to determine the amount of pain and the
perceived ability to carry out functions at the present
time (0 =no pain or full ability to function; 4 =worst
possible pain and/or unable to perform this function at
all). Scoring varies between 0 and 40 and functional
status deteriorates as scores increase [21,22].
2.5. Short Form-36
The SF-36 is a 36-item self-administered question-
naire used to measure health-related quality of life of
the subjects. The reliability and validity of the Turkish
version has been proven. It consists of eight subscales
including physical functioning, role limitations physi-
cal, bodily pain, general health perceptions, vitality, so-
cial functioning, role limitations emotional, and men-
tal health. Scores vary between 0 and 100, 100 indicat-
ing best possible health status and 0 worst health sta-
tus. In order to make the comparison of the index with
many findings, a special calculation method is used
with the data of the normal population.With the scores
of first four subscales, the physical component sum-
mary score and with the scores of last four subscales,
the mental component summary score was calculated.
Hence, physical and mental quality of life scores were
obtained [23,24].
2.6. Statistical analysis
Whether the findings were distributed normally was
examined by the Shapiro-Wilkes test. If the data were
distributed normally, parametric methods were used,
and in the analysis of the data that are not distributed
normally, non-parametric methods were used. In the
comparison of two groups, the independent sample
t-test or Mann-Whitney U test was used depending
on whether the data were distributed normally or not.
When there were more than two groups, one way
variance analysis or the Kruskal-Wallis test was used,
again depending upon whether the data were dis-
tributed normally or not. In the examination of the re-
lationship between continous variables, Pearson corre-
lation or Spearman rank correlation coefficients were
calculated. The analysis of categorical variables was
carried out with the chi-square test. In order to evalu-
ate the effect of more than one variable on the PSQI,
multiple regression analysis was used.
Statistical analysis was made with SPSS v.11.5 and
MedCalc v.11.0 programs. In statistical analysis, P<
0.05 was considered significant. Descriptive statistics
for continuous variables were expressed as mean and
standard deviation and descriptive statistics for cate-
gorical variables were outlined as frequency and per-
centage in the tables.
3. Results
The mean ages of patients and HCs were 50.2 ±
14.2 years (range: 20 to 78) and 49.7 ±13.6 years
436 M. Sezgin et al. / Sleep quality in patients with CLBP
Fig. 1. Education level in patient and control groups. (Colours are visible in the online version of the article; http://dx.doi.org/10.3233/BMR-
140537)
Fig. 2. Occupational distribution of patient and control groups. (Colours are visible in the online version of the article; http://dx.doi.org/10.3233/
BMR-140537)
Table 1
The demographic characteristics of patients and controls
Variables Patients Controls P
Mean ±SD Mean ±SD
Age 50.2 ±14.2 49.7 ±13.6 0.07
Height 166.9 ±8.5 168.4 ±9.1 0.09
Weight 76.6 ±12.0 72.5 ±10.5 <0.001
BMI 27.5 ±4.3 25.5 ±3.1 <0.001
(range 21 to 73, respectively). The groups were sim-
ilar in terms of age, sex, and height (P>0.05), but
the weight and BMI of patients with CLBP were sig-
nificantly higher than the HCs (P<0.001, Table 1).
Also, there were significant differences between the
groups in terms of education and occupation (p<
0.001, Figs 1–2). There was only low back pain in 92
patients (46%), low back and one back pain in 26 pa-
tients (13%), and low back and two leg pain in 82 pa-
tients (41%). The pain durations were in 22 patients
(11%) <1year,in96patients(48%)1to5years,in52
patients (26%) 6 to 10 years and in 30 patients (15%)
>11 years.
3.1. Pittsburgh Sleep Quality Index
The mean total scores of PSQI were 8.1 ±4.3
(range: 1 to 18) in the patients group and 4.6 ±3.4
(range: 1 to 16) in the HCs group, with a statistical dif-
ference (P<0.001). Similarly, there were significant
differences between the groups for subscores (P<
0.001), without the use of sleep medications (P>
M. Sezgin et al. / Sleep quality in patients with CLBP 437
Table 2
The PSQI scores of patient and control groups
PSQI Patients Controls P
Mean ±SD Mean ±SD
PSQI total 8.1 ±4.3 4.6 ±3.4 <0.001
Subjective sleep quality 1.3 ±0.7 0.7 ±0.8 <0.001
Sleep latency 1.6 ±0.9 0.8 ±0.9 <0.001
Sleep duration 1.2 ±1.0 0.7 ±0.8 <0.001
Habitual sleep efficiency 0.8 ±0.8 0.4 ±0.5 <0.001
Sleep disturbance 1.6 ±0.6 1.1 ±0.3 <0.001
Use of sleeping medications 0.3 ±0.8 0.2 ±0.6 0.06
Daytime dysfunction. 0.9 ±0.9 0.4 ±0.7 <0.001
Table 3
Comparison of the sleep quality of patients and controls according to BMI
BMI Patients Controls P P
PSQI total <25 7.9 ±4.1 4.4 ±3.6 <0.001 0.905
25 8.3 ±4.5 4.7 ±3.4 <0.001
Subjective sleep quality <25 1.4 ±0.7 0.7 ±0.8 <0.001 0.147
25 1.3 ±0.7 0.9 ±0.8 <0.001
Sleep latency <25 1.7 ±0.9 0.8 ±0.9 <0.001 0.623
25 1.7 ±0.9 0.9 ±0.9 <0.001
Sleep duration <25 1.2 ±1.0 0.9 ±0.9 0.067 0.088
25 1.3 ±1.0 0.6 ±0.7 <0.001
Habitual sleep efficiency <25 0.9 ±0.8 0.4 ±0.5 <0.001 0.248
25 0.8 ±0.8 0.4 ±0.5 <0.001
Sleep disturbance <25 1.6 ±0.6 1.0 ±0.3 <0.001 0.995
25 1.7 ±0.6 1.2 ±0.4 <0.001
Use of sleeping medications <25 0.2 ±0.7 0.2 ±0.6 0.841 0.331
25 0.4 ±1.0 0.3 ±0.7 0.067
Daytime dysfunction <25 0.8 ±0.9 0.4 ±0.7 <0.001 0.628
25 1.0 ±0.9 0.5 ±0.7 <0. 001
BMI: Body Mass Index.
Table 4
The PSQI scores of female and male patients
PSQI Female patients Male patients P
Mean ±SD Mean ±SD
PSQI total 8.7 ±4.5 7.5 ±4.1 0.047∗
Subjective sleep quality 1.4 ±0.7 1.2 ±0.7 0.121
Sleep latency 1.8 ±0.9 1.5 ±0.9 0.034∗
Sleep duration 1.1 ±1.0 1.3 ±0.9 0.405
Habitual sleep efficiency 0.7 ±0.7 0.9 ±0.8 0.151
Sleep disturbance 1.8 ±0.6 1.5 ±0.5 0.001∗
Use of sleeping medications 0.6 ±1.0 0.1 ±0.5 0.001∗
Daytime dysfunction. 1.1 ±0.8 0.8 ±0.9 0.021∗
Significant P values.
0.05, Table 2). While the PSQI total score was over 5,
at 65.5% (n=131) of the patients, this rate was 29.5%
(n=59) at the HCs group. Sleep latency, sleep distur-
bance, subjective sleep quality, and sleep duration were
the most deteriorating sleep parameters in the CLBP.
When we compared the sleep quality of patients
and controls according to BMI, there was no differ-
ence between subjects with >25 BMI and subjects
with <25 BMI (Table 3). But, when we examined
the relation between BMI and sleep quality in patients
with CLBP, we determined that sleep disturbance (r=
0.250, P<0.001) and daytime dysfunction (r=
0.175, p=0.013) subscales had weakly positive rela-
tion with BMI.
There was a statistically significant difference at the
PSQI total score between women and men patients (8.7
438 M. Sezgin et al. / Sleep quality in patients with CLBP
Table 5
SF-MPQ, FRI, and SF-36 scores of the patients
All Patients All Patients Male Patients Female Patients P values
Mean ±SD Min-Max Mean ±SD Mean ±SD
SF-MPQ total 16.7 ±8.0 3–39 16.8 ±8.3 16.5 ±7.8 0.774
SF-MPQ affective 3.9 ±2.3 0–11 4.9 ±2.3 3.5 ±2.3 0.01∗
SF-MPQ sensory 12.7 ±6.2 3–32 12.4 ±6.4 12.9 ±6.40 0.565
SF-MPQ VAS 6.9 ±1.2 4–9 6.9 ±1.2 6.9 ±1.3 0.934
SF-MPQ ETPI 2.8 ±0.7 1–5 2.8 ±0.8 2.8 ±0.7 0.651
SF-36 PCS 39.1 ±4.5 28.7–49.3 40.1 ±4.3 38.1 ±4.4 0.002∗
SF-36 MCS 41.7 ±4.5 28.1–54.0 40.5 ±4.6 42.9 ±4.1 0.001∗
FRI 8.5 ±3.0 2.0–15.6 8.4 ±3.1 8.6 ±2.9 0.598
VAS: Visual analog scale, ETPI: The evaluative total pain intensity, PCS: Physical component summary, MCS: Mental component summary,
FRI: Functional Rating Index. ∗Significant P values.
Table 6
The corelations between PSQI and SF-36 in the patients
PSQI SF-36 PCS SF-36 MCS
rp r p
PSQI total −0.384 <0.001∗0.081 >0.05
Subjective sleep quality −0.406 <0.001∗0.076 >0.05
Sleep latency −0.349 <0.001∗0.130 >0.05
Sleep duration −0.132 >0.05 −0.031 >0.05
Habitual sleep efficiency −0.186 0.008∗−0.050 >0.05
Sleep disturbances −0.392 <0.001∗0.159 <0.02∗
Use of sleeping medications −0.234 0.001∗0.068 >0.05
Daytime dysfunction −0.352 <0.001∗0.097 >0.05
PCS: Physical component summary, MCS: Mental component summary. ∗Significant P values.
±4.5 and 7.5 ±4.1, P=0.04, respectively). In ad-
dition, sleep latency, sleep disturbance, use of sleep
medications, and daytime dysfunction subscores were
significantly worse in the women patients with CLBP
(P<0.05, Table 4).
When we examined the relation between age and
sleep quality in patients with CLBP, only there was a
weak positive relationship between sleep disturbance
subscale of the PSQI and age (r=0.290, P<0.001).
Similarly, we found significant relationships between
the PSQI total scores and complaint types (P=0.006).
Sleep quality was especially worse in those with low
backandtwolegpainthanthosewithonlylowback
pain or low back and one leg pain (9.2 ±4.2, 7.6 ±
4.5, and 6.5 ±3.3, respectively, P=0.006). In addi-
tion, in patients with pain complaints >11 years, the
daytime dysfunction subscore was significantly worse
(1.3 ±0.8, P=0.02). Any statistically significant dif-
ference was not found between occupation, education
and PSQI total score (P>0.05).
3.2. Short Form McGill Pain Questionnaire,
Functional Rating Index, and Short Form-36
The SF-MPQ, FRI, and SF-36 scores of patient
group are outlined in Table 5. The SF-MPQ sensory,
affective, total, VAS, and ETPI scores had positive re-
lations with the PSQI total score (r=0.47, r=0.35,
r=0.47, r=0.34, r=0.35, respectively, P<
0.001). Likewise, there was a positive correlation be-
tween FRI score and PSQI total scores (r=0.57,
P<0.001). While there were negative correlations
between the PSQI scores and the physical component
summary scores of SF-36, there was not relation be-
tween the PSQI scores and the mental component sum-
mary scores of the SF-36, without sleep disturbance
(Table 6).
4. Discussion
In this cross-sectional study, we showed that the
sleep quality evaluated by PSQI was significantly im-
paired in the patients with CLBP. Excluding use of
sleep medications, the six components of PSQI in
CLBP; sleep latency, sleep duration, subjective sleep
quality, habitual sleep efficiency, sleep disturbances,
and daytime dysfunction were worse than the HCs. The
highest impairmentwas seen at sleep latency, sleep dis-
turbance, subjective sleep quality, and sleep duration.
Previous studies had shown that sleep quality of the
individual, when the PSQI total score was more than 5,
M. Sezgin et al. / Sleep quality in patients with CLBP 439
was insufficient with a sensitivity of 89.6% and speci-
ficity of 86.5%. This refers to severe disturbance at
least in two components or moderate disturbance in
three components [16–18]. In this present study, the
mean PSQI score of patients and controls were 8.1 and
4.6 respectively. Also, the PSQI total score of 131 pa-
tients with CLBP was over 5. Based on this results
of our study group, we suggest that sleep disturbances
is present in approximately 65% of the patients with
CLBP. Recently, Alsaadi et al. [25] have shown that
the prevalence of sleep disturbance was 58.9% in pa-
tients with low back pain and this finding was similar to
those of previous studies reporting sleep disturbances
in more than 50% (43–70%) of patients with chronic
nonmalignant pain [8–12].
Atkinson et al. [8] reported that the PSQI total score
was 11 in the patients with CLBP and at least 50%
of the patients had a sleep disorder. A cross-sectional
study determined that the mean PSQI score was 10.4
in 268 patients with CLBP [26]. Disadvantages of the
above studies were the absence of a control group and
the fact that subscores were not evaluated separately.
Later, Marty et al. [27] compared sleep quality in 101
CLBP patients and 97 sex- and aged-matched healthy
controls. The patients had significantly higher scores
in all items of the PSQI than the controls. The mean
PSQI scores were 4.7 for the controls and 10.9 for the
patients. The 49.5 % of patients said that their sleep
quality was poor or very poor [27].
The mean PSQI score of our patients with CLBP
was 8.1, a little better than other studies, which may be
explained by the exclusion of depressive patients from
our study. In previous studies, a negative mood (e.g.
anxiety ad depression) was shown to be strongly asso-
ciated with sleep disturbance and pain in this popula-
tion and might have influenced the perception of sleep
disturbances [28,29]. Additionally, there is a well-
established history of sleep disturbance in patients suf-
fering from depression. Depressed patients experience
frequent awakenings, longer sleep latencies, and REM
abnormalities [29]. For example, Harman et al. [30]
evaluated sleep quality of depressed and nondepressed
patients with CLBP and controls, and observed that to-
tal PSQI scores were the highest in depressed CLBP
patients (13.7, 10.8 and 2.11 respectively).
Further, few studies exclude individuals with major
depressive disorders. Therefore, authors have advised
not to take any sleep medication during the sleep mea-
surement period [28,29]. Based on this information, we
excluded those with a history of drug use for primary
insomnia or depression from this study. Hence, in our
study,there was no difference between patient and con-
trol groups in terms of the use of sleep medications.
In two more recent studies, sleep quality of CLBP
patients was evaluated both subjectively and objec-
tively. Authors concluded that sleep was significantly
disturbed both subjectively and objectively in this pop-
ulation [31,32]. Because there was no actigraphy or
polysomnography records in our study population, we
could not evaluate our patients in this respect, which
may be a disadvantage of our study.
In the present study, the sleep of women patients
with CLBP was poorer than that of men. Especially,
sleep latency, sleep disturbance, use of sleep medica-
tions, and daytime dysfunction components were sig-
nificantly worse in women. Unlike our findings, one
study reported that the sleep of men with chronic pain
was more fragmented than women [3]. The differ-
ences in the sleep of men and women with CLBP have
not been reported previously. However, pain scores
(SF-MPQ) without affective component and disabilty
scores (FRI) were similar in both female and male pa-
tients. But, women with CLBP had higher BMI and
lower physical component summary score of the SF-
36. Further studies with a larger sample are needed to
explore gender differences in sleep.
In the present study study, we also established that
high BMI, older age, longer complaint duration and
complaint type had adverse effects on the sleep qual-
ity in CLBP. As far as we know, there is no previous
study examining the relationship between the clinical
status and sleep quality in patients with CLBP. Con-
trary to our results, there was one study reporting the
age-related results. In 167 patients with degenerative
spinal disease or postlaminectomy syndrome, Menefee
et al. [13] had shown that sleep latency and daytime
sleepiness were correlated with younger age. Unlike
this study, we did not include patients with CLBP who
underwent surgery in our study.
Marin et al. [26] evaluated sleep quality (PSQI)
and pain (SF-MPQ) of CLBP patients. They showed
significant correlation between sleep and pain [26].
Similarly, we also established that the sleep quality
(PSQI) was associated with pain (SF-MPQ) in the
CLBP. Sleeplessness or disturbance of sleep quality
may decrease the pain threshold through neurobiolog-
ical modifications which may be mediated by the re-
duction of the sensitivity of μand δopioid receptors or
of endorphine secretions [6,26]. It was previously sug-
gested that in patients with chronic pain, as pain sever-
ity increased, sleep was disturbed more, sleep interrup-
tions increased, and falling into sleep was more diffi-
440 M. Sezgin et al. / Sleep quality in patients with CLBP
cult [3,29,31]. It was demonstrated that sleep was less
refreshing in patients with chronic pain compared to
healthy peoples, and they had more alpha EEG sleep.
Abnormality in alpha wave EEG (the frequency of al-
pha waves may be related to the increase in subjective
pain and decrease in energy) may be due to the distur-
bance related to pain during sleep [6].
Also, sleep disorders may give rise to stress in daily
life and difficulties in carrying out even simple tasks
and to the weakening of memory [15]. In the present
study, we showed that impaired sleep quality have neg-
ative impact on quality of life (SF-36), particularly its
physical component. Likewise, Menefee et al. [13],
Ancoli-Israel [15] and Marty et al. [27] reported that
both quality and quantity of sleep may exerted adverse
effects on quality of life in this patients.
In addition, we determined a correlation between
functional status (disability) and sleep quality of pa-
tients with CLBP. This relationship was stronger than
that with pain intensity. As a patient’s functional sta-
tus deteriorated, the sleep quality also worsened. In re-
cent studies, it was revealed that objective sleep mea-
surements were related with pain, while they were not
related with quality of life and disability scores. How-
ever, they found that PSQI global score, which they
used as a subjective measurement, was associated with
pain, disability, and physical component scores of the
SF-36. Authors suggested that subjective sleep mea-
surements were more consistent with pain, quality of
life, and disability measurements than objective sleep
measurements [31,32]. Also, the validity of objective
sleep measures should be further investigated in the
CLBP.
One of the most important weaknesses of our study
was that we did not have polysomnographic or acti-
graphic records, as it would bring extra cost to the
study budget. Other weakness was the fact that the ef-
fect of depression on sleep was not investigated since
we did not include patients who use antidepressant
drugs into the study. Furthermore, these findings may
not be generalized to the CLBP pain population be-
cause the study was carried out in patients who applied
to tertiary a physical therapy and rehabilitation center,
which is cross-sectional. The selection of friends, hos-
pital staff and relatives for the control group may cre-
ate a bias. This selection may be another weakness of
this study.
In conclusion, we established that the patients with
CLBP had poorer sleep quality. This condition was
closely related to functional status and pain of the pa-
tients. Ultimately, the deterioration of sleep quality ad-
versely affected the quality of life. It is our suggestion
that when examining and planning the management
of such patients, sleep disorder and associated factors
should also be taken into account. Further studies are
required to investigate the influences of pharmacolog-
ical and nonpharmacological treatments on the sleep
quality of patients with CLBP.
References
[1] Woolf AD, Pfleger B: Burden of major musculoskeletal con-
ditions. Bull World Health Organ 8: 646–656, 2003.
[2] Andersson GB: Epidemiological features of chronic low-back
pain. Lancet 354: 581-585, 1999.
[3] Call-Schmidt TA, Richardson SJ: Prevalence of sleep distur-
bance and its relationship to pain in adults with chronic pain.
Pain Manag Nurs 4: 124-133, 2003.
[4] Cole JC, Dubois D, Kosinski M: Use of patient-reported sleep
measures in clinical trials of pain treatment: A literature re-
view and synthesis of current sleep measures and a concep-
tual model of sleep disturbance in pain. Clin Ther 29 (Suppl):
2580-2588, 2007.
[5] Naughton F, Ashworth P, Skevington SM: Does sleep quality
predict pain-related disability in chronic pain patients? The
mediating roles of depression and pain severity. Pain 127:
243-252, 2007.
[6] Moldofsky, H: Sleep and pain. Sleep Med Rev 5: 385-396,
2001.
[7] Kundermann B, Krieg JC, Schreiber W, Lautenbacher S: The
effect of sleep deprivation on pain. Pain Res Manag 9(1): 25-
32, 2004.
[8] Atkinson JH, Ancoli-Israel S, Slater MA, Garfin, SR, Gıllin
JC: Subjective sleep disturbance in chronic back pain. Clin J
Pain 4: 225–232, 1988.
[9] Jamieson AH, Alford CA, Bird HA, Hindmarch I, Wrigth
V: The effect of sleep and nocturnal movements on stiffness,
pain, and psychomotor performance in ankylosing spondyli-
tis. Clin Exp Rheumatol 13: 73–78, 1995.
[10] Leigh TJ, Hindmarch I, Bird HA, Wrıght V: Comparison
of sleep in osteoarthritic patients and age and sex matched
healthy controls. Ann Rheum Dis 47: 40-42, 1988.
[11] Lobbezoo F, Visscher CM, Naeije M: Impaired health status,
sleep disorders, and pain in the craniomandibular and cervical
spinal regions. Eur J Pain 8: 23-30, 2004.
[12] Pilowsky I, Crettenden I, Townley M: Sleep disturbance in
pain clinic patients. Pain 23: 27-33, 1985.
[13] Menefee LA, Frank ED, Doghramji K, Picarello K, Park JJ,
Jalali S, Perez-Schwartz L: Self-reported sleep quality and
quality of life for individuals with chronic pain conditions.
Clin J Pain 16: 290-297, 2000.
[14] Rabini A, Aprile I, Padua L, Piazzini DB, Maggi L, Ferrara
PE, Amabile E, Bertolini C: Assessment and correlation be-
tween clinical patterns, disability and health-related quality of
life in patients with low back pain. Eura Medicophys 43: 49-
54, 2007.
[15] Ancoli-Israel S: The impact and prevalence of chronic insom-
nia and other sleep disturbances associated with chronic ill-
ness. Am J Manag Care 12: 221-229, 2006.
[16] Buysse DJ, Reynolds CF, Monk TH, Berman SR, Kupfer DJ:
The Pittsburgh Sleep Quality Index: A new instrument for
M. Sezgin et al. / Sleep quality in patients with CLBP 441
psychiatric practice and research. Psychiatry Res 28: 193-213,
1989.
[17] Carpenter JS, Andrykowski MA: Psychometric evaluation of
the Pittsburgh Sleep Quality Index. J Psychosom Res 45: 5-
13, 1998.
[18] A˘
gargün MY, Kara H, Anlar O: Pittsburgh Uyku Kalitesi
˙
Indeksi’nin Geçerli˘
gi ve Güvenirli ˘
gi. Türk Psikiyatri Derg 7:
107-115, 1996.
[19] Melzack R: The short-form McGill Pain Questionnaire, Pain
30: 191-197, 1987.
[20] Yakut Y, Yakut E, Bayar K, Uygur F: Reliability and valid-
ity of the Turkish version short-form McGill pain question-
naire in patients with rheumatoid arthritis. Clin Rheumatol 26:
1083-1087, 2007.
[21] Feise RJ, Michael Menke J: Functional rating index: A new
valid and reliable instrument to measure the magnitude of
clinical change in spinal conditions. Spine 26: 78-87, 2001.
[22] Bayar B, Bayar K, Yakut E, Yakut Y: Reliability and validity
of the Functional Rating Index in older people with low back
pain: preliminary report. Aging Clin Exp Res 16: 49-52, 2004.
[23] Kocyigit H, Aydemir O, Fisek G, Olmez N, Memis A: Va-
lidity and reliability of Turkish version of Short form 36: A
study of a patients with romatoid disorder. Journal of Drug
and Therapy (in Turkish) 12: 102-106, 1999.
[24] Ware JE Jr, Gandek B: Overview of the SF-36 Health Survey
and the International Quality of Life Assessment (IQOLA)
Project. J Clin Epidemiol 51: 903-912, 1998.
[25] Alsaadi SM, McAuley JH, Hush JM, Maher CG: Prevalence
of sleep disturbance in patients with low back pain. Eur Spine
J 20: 737-743, 2011.
[26] Marin R, Cyhan T, Miklos W: Sleep disturbance in patients
with chronic low back pain. Am J Phys Med Rehabil 85: 430-
435, 2006.
[27] Marty M, Rozenberg S, Duplan B, Thomas P, Duquesnoy B,
Allaert F: Quality of sleep in patients with chronic low back
pain: A case-control study. Eur Spine J 17: 839-844, 2008.
[28] Morin CM, Gibson D, Wade J: Self-reported sleep and mood
disturbance in chronic pain patients. Clin J Pain 14: 311-314,
1998.
[29] Menefee LA, Cohen MJ, Anderson WR, Doghramji K, Frank
ED, Lee H: Sleep disturbance and nonmalignant chronic pain:
A comprehensive review of the literature. Pain Med 1: 156-
172, 2000.
[30] Harman K, Pivik RT, D’Eon JL, Wilson KG, Swenson JR,
Matsunaga L: Sleep in depressed and nondepressed partic-
ipants with chronic low back pain: electroencephalographic
and behaviour findings. Sleep 25: 775-783, 2002.
[31] O’Donoghue GM, Fox N, Heneghan C, Hurley DA: Objec-
tive and subjective assessment of sleep in chronic low back
pain patients compared with healthy age and gender matched
controls: A pilot study. BMC Musculoskelet Disord 10: 122,
2009.
[32] van de Water AT, Eadie J, Hurley DA: Investigation of sleep
disturbance in chronic low back pain: An age- and gender-
matched case-control study over a 7-night period. Man Ther
16: 550-556, 2011.
