Multicenter cross-sectional analysis of values of glycated haemoglobin (HbA1c) in Polish children and adolescents with long-term type 1 diabetes in Poland: PolPeDiab study group

Abstract

Introduction:
Glycated haemoglobin is currently a golden standard of evaluation of metabolic control of diabetes. According to the Evidence based Medicine data, better metabolic control of diabetes decreases the prevalence of chronic complications.

Aim of the study:
to analyse HbA1c in children with a longer duration of type 1 diabetes mellitus (t1DM).

Material and methods:
We analysed an epidemiological database (2006-2009) of 7783 HbA1c values of 996 children (465 girls) with t1DM treated at three academic centres (Gdańsk, Łódź, Katowice) in Poland. the mean age was 13.04±3.43 years and the mean duration of diabetes was 6.93±2.33 years.

Results:
the overall mean HbA1c was 7.6±1.5% (by age groups: 7.0±0.8%, 2-5 yrs; 7.1±1.0%, 6-10 yrs; 7.8±1.7%, 11-19 yrs) without gender-related differences. HbA1c increased significantly with increasing age and t1DM duration. HbA1c values differed significantly between the centres. A group of 455 (55.7%) children reached a stable course of diabetes with HbA1c <7.5%, and 110 (13.5%) had HbA1c levels >9%. The mean HbA1c ?6.5% was found in 150 children (18.4%).

Conclusions:
In more than 50% of Polish children with longer t1DM duration, the international target of glycaemic control (HbA1c) is achieved; however, only 18% of them reached Polish national target. Age, t1DM duration and centre-specific factors influence the HbA1c values.

Full text

Pediatric Endocrinology, Diabetes and Metabolism
2012, 18, 4, 125-129
ISSN 2081-237X
125
PRACE ORYGINALNE / Original articles
Multicenter cross-sectional analysis of values of glycated haemoglobin
(HbA1c) in Polish children and adolescents with long-term type 1diabetes
in Poland: PolPeDiab study group
Wieloośrodkowa analiza wartości hemoglobiny glikowanej (HbA1c) wpopulacji dzieci polskich zdługim okresem trwania
cukrzycy typu 1: badanie grupy PolPeDiab
Przemysława Jarosz-Chobot1, Joanna Polańska2, Małgorzata Myśliwiec3, Agnieszka Szadkowska4,
WojciechFendler4,Halla Kamińska5, Miron Chumiecki5, Beata Mianowska4, Ilona Techmańska3, Beata Sztangierska3,
WojciechMłynarski4 on behalf PolPeDiab study group
1 Department of Paediatrics, Endocrinology and Diabetes, Medical University of Silesia, Poland
2 System Engineering Group, Faculty of Automatic Control, Electronics, and Computer Science, Silesian University of Technology, Gliwice, Poland
3 Department of Paediatrics, Haematology, Oncology and Endocrinology, Medical University of Gdańsk, Poland
4 Department of Paediatrics, Oncology, Haematology and Diabetology, Medical University of Łódź, Poland
5 Department of Paediatrics, Endocrinology and Diabetes, Upper Silesia Centre for Child Health, Poland
ABSTRACT
Introduction: Glycated haemoglobin is currently agolden standard of evaluation of metabolic control of diabetes.
According to the Evidence Based Medicine data, better metabolic control of diabetes decreases the prevalence of
chronic complications.
Aim of the study: To analyse HbA1c in children with alonger duration of type 1diabetes mellitus (T1DM).
Material and methods: We analysed an epidemiological database (2006-2009) of 7783HbA1c values of 996chil-
dren (465 girls) with T1DM treated at three academic centres (Gdańsk, Łódź, Katowice) in Poland. The mean age
was 13.04±3.43 years and the mean duration of diabetes was 6.93±2.33 years.
Results: The overall mean HbA1c was 7.6±1.5% (by age groups: 7.0±0.8%, 2-5 yrs; 7.1±1.0%, 6-10 yrs; 7.8±1.7%, 11-19
yrs) without gender-related differences. HbA1c increased significantly with increasing age and T1DM duration.
HbA1c values differed significantly between the centres. Agroup of 455(55.7%) children reached astable course
of dia betes with HbA1c <7.5%, and 110(13.5%) had HbA1c levels >9%. The mean HbA1c ≤6.5% was found in 150chil-
dren (18.4%).
Conclusions: In mo re th an 50 % of P olish chil dren with lon ger T1DM dur atio n, the inter nati onal targe t of g lyca emic
control (HbA1c) is achieved; however, only 18% of them reached Polish national target. Age, T1DM duration and
centre-specific factors influence the HbA1c values.
KEY WORDS:
HbA1c, diabetes type 1, children, metabolic control
STRESZCZENIE
Wprowadzenie: Oznaczenie wartości HbA1c wsurowicy krwi jest złotym standardem oceny stopnia wyrównania
metabolicznego cukrzycy. Zgodnie z wiarygodnymi dowodami naukowymi (Evidence Based Medicine)
prawidłowa kontrola metaboliczna cukrzycy zmniejsza częstość występowania przewlekłych powikłań.
Cel pracy: Ocena HbA1c udzieci zdługo trwającą cukrzycą typu 1(T1DM).
Materiał imetody: Analizą objęto dane pochodzące zlat 2006-2009. Oceniono 7783oznaczeń HbA1c u996 dzie-
ci (w tym 465dziewcząt) zT1DM, leczonych w3 ośrodkach wPolsce (Gdańsk, Łódź, Katowice). Średni wiek pacjen-
tów wynosił 13,04±3,43 roku. Średni czas trwania cukrzycy wynosił 6,93±2,33 roku.
Wyniki: Całkowite średnie stężenie HbA1c wynosiło 7,6±1,5% (w grupie 2-5 lat: 7,0±0,8%, 6-10 lat: 7,1±1,0%, 11-19
lat: 7,8±1,7% ), bez istotnych statystycznie różnic wodniesieniu do płci. Stężenie HbA1c znacząco wzrastało wraz
zwiekiem iczasem trwania T1DM. Wartości HbA1c różniły się między ośrodkami. 455(55,7%) dzieci uzyskało sta-
bilny stopień wyrównania cukrzycy, ze stężeniem HbA1c <7,5%. 110(13,5%) dzieci uzyskało stężenia HbA1c >9%.
Średnią wartość HbA1c ≤6,5% uzyskano u150 dzieci (18,4%).
Wnioski: Uwięcej niż 50% dzieci wPolsce zdługo trwającą cukrzycą typu 1osiągnięto międzynarodowe wartości
docelowe wyrównania glikemii; jednak krajowe wartości docelowe glikemii osiąga jedynie 18% znich. Wiek, czas
trwania cukrzycy typu 1oraz regionalne różnice wleczeniu cukrzycy znacząco wpływają na wartości HbA1c.
SŁOWA KLUCZOWE:
HbA1c, cukrzyca typu 1, dzieci, kontrola metaboliczna

126
Pediatric Endocrinology, Diabetes and Metabolism 2012, 18, 4
Jarosz-Chobot P., Polańska J., Myśliwiec M. i wsp.
Wieloośrodkowa analiza wartości hemoglobiny glikowanej (HbA1c)...
Introduction
Glycated haemoglobin is currently an undisputed golden
(although imperfect) standard of evaluation of metabolic con-
trol of diabetes. According to the Evidence Based Medicine
data, better metabolic control of diabetes decreases the preva-
lence of chronic complications [1-3]. The annually updated and
published recommendations for the target levels of glycated
haemoglobin developed by eminent scientific societies confirm
its validity in diabetology [4-6]. In the Caucasian population,
type 1diabetes is most common in children and adolescents
(Poland ~ 98%). In the recent years, owing to the generally rec-
ognised results of the DDCT test and technological progress,
treatment of type 1diabetes was significantly intensified along
with an increase in its safety [7-9]. The organisation of the Pol-
ish specialist diabetes care for children and adolescents has its
individual particularities. It is centralised (usually 1large centre
in the region) with wide access to new technologies (more than
70% of patients treated with CSII). Visits are held on average
every 8-12 weeks. The visits and blood glucose tests are not
limited. Moreover, national recommendations for diabetes
treatment in children and adolescents are published annually
by Diabetes Poland, with the recommendation of the target
glycated haemoglobin below or equal to 6.5 for children of all
age groups [6]. The above facts prompted the study authors
to analyse glycated haemoglobin values of 3largest regional
paediatric university diabetes centres representative for Poland,
within the Polish Paediatric Diabetes Study Group (PolPeDiab).
Additionally, asimilar composition of the Diabetes Manage-
ment Teams including paediatricians and diabetes specialists
and good cooperation among the aforementioned academic
centres allowed to conduct avaluable analysis of data collected
prospectively.
Aim of the study
To evaluate glycated haemoglobin levels with long-term
type 1diabetes in Poland
Material and methods
Within the healthcare system in Poland, each child with
diabetes up to 18years of age is covered by specialist diabetes
care. Academic paediatric diabetes centres (representing the
PolPeDiab group) in the regions: Łódzkie (Łódź), Pomorskie
(Gdańsk) and Śląskie (Katowice) cover more than 25% of the
Polish population. All patients with type 1diabetes are treated
by functional intensive insulin therapy: with the use of aper-
sonal insulin pump (in younger age groups: 90-100%) or pens,
usually with the use of rapid-acting insulin analogues. In 2006-
2009, 7783results of HbA1c measurements in 996children (465
girls) aged 2.23-19.74 years, mean 13.04±3.43 years, mean dis-
ease duration of 6.93±2.33 years (range 3.00÷12.75) and the
mean number of measurements per patient 7.95±3.20 (tab. I)
were collected at the 3aforementioned regional paediatric dia-
betes centres. The following age groups were adopted: 2-5; 6-10
and 11-19 years. Only HbA1c values in children and adolescents
aged 2-19 years having type 1diabetes for at least 2years but
not longer than 10years were eligible for the analysis. Addi-
tionally, in each patient at least 4HbA1c measurements within
the follow-up period with an interval not lower than 1month
were required. Measurements performed at intervals short-
er than 1month were averaged. The number of children and
adolescents with type 1diabetes and HbA1c measurements
in the individual regions were as follows: Gdańsk 175chil-
dren (90 girls), 1012measurements; Łódź 372children (164
girls), 2896measurements; Katowice 449children (211 girls),
3875measurements. Measurements of glycated haemoglobin
were performed by HPLC (Bio-Rad VARIANT TM) in regional lab-
oratories in Gdańsk, Katowice and Łódź. The specified values
correspond to the DDCT normal range (4.0-6.0%).
Statistics
For each of the analysed continuous measurement varia-
bles, basic descriptive statistics were calculated for the sample:
the arithmetic mean and the standard deviation, and 95% con-
fidence intervals were estimated on their basis for the mean
value in the population. Detection of outliers was performed
with the use of the Grubb’s test criterion. The hypothesis about
the consistency of the distributions of the analysed variables
with normal distribution was verified with the use of the Lil-
liefors test. In the case of separate analysis in age groups, the
HbA1c measurement was attributed to the age group to which
the child’s age belonged at the time when the measurement
was performed. A comparative analysis of the mean values
of continuous variables depending on the selected grouping
Table I: Overal comparison of clinical parameters and HbA1c values by gender, overall
Tabela I: Porównanie parametrów klinicznych iwartości HbA1c, wzależności od płci
Clinical parameter
Parametry kliniczne Boys
Chłopcy
N=531
Girls
Dziewczęta
N=465
ANOVA
p-value
wartość p
Age at disease onset [years] / Wiek zachorowania (lata) 8.07±3.52 7.96±3.47 0.616133
Current duration of disease [years] / Czas trwania choroby (w latach) 6.94±2.35 6.93±2.32 0.962743
Constant component HbA1c [%] / Stała wartość HbA1c7.60±1.24 7.74±1.48 0.118062
Number of HbA1c measurements in the follow-up period (n) / Liczba oznaczeń HbA1c wokresie obserwacji 8.03±3.17 7.85±3.24 0.369600
Follow-up time [years] / Okres obserwacji (lata) 2.47±0.89 2.41±0.89 0.338106
Mean number of HbA1c measurements per year of follow-up (n)
Średnia liczba oznaczeń HbA1c na rok okresu obserwacji 3.46±1.16 3.44±1.13 0.730626
Percent of disease duration subject to follow-up [%] / Procent obserwacji zczasu trwania choroby 37.53±14.04 36.72±13.87 0.359455
Coefficient of variation CV [%] / Współczynnik zmienności 8.49±5.29 9.07±5.52 0.088853

127
Jarosz-Chobot P., Polańska J., Myśliwiec M. et al.
Multicenter cross-sectional analysis of values of glycated haemoglobin (HbA1c)...
factors (gender, region, age group, year of follow-up) was per-
formed with the use of the multi-way ANOVA algorithm, taking
into account both main effects and mutual interactions among
the factors. Pairwise comparisons allowed to conduct adetailed
analysis of the effects of the individual factors. To assess propor-
tions, Wilson’s estimator and 95% confidence limits obtained
with the use of the Woolf’s method were used. Acomparative
analysis of proportions was performed with the use of the
Gstatistics and the likelihood ratio test. Statistically significant
results were deemed to be those with p<0.05.
Results
HbA1c value –overall
For all the patients, the mean HbA1c value was 7.62±1.54%.
No statistically significant differences were observed between
the girls and boys (girls 7.67±1.62%, n=3583 vs. boys
7.57±1.45%, n=4200; p=0.0871), regardless of the age group
(tab. II). The mean HbA1c value did not differ statistically in the
subsequent years of observations and was found to change as
follows: year 2006: 7.68±1.50% (n=1544), year 2007: 7.56±1.52%
(n=2115), year 2008: 7.64±1.51% (n=2235) and year 2009:
7.61±1.61% (n=1889). In amulti-factorial analysis of variance
taking into account the year of follow-up (Year), the age group
(Age), the region (Region), the patient’s gender (Gender) and
pairwise interactions, statistically significant differences of the
HbA1c values were observed for the age groups and regions (p
<0.000001). The patients aged 11-19 years (7.83±1.66%, N=5583)
have asignificantly higher mean HbA1C in comparison with the
patients aged 2-5 years (7.05±0.83%, n=258; p<0.000001) and
those aged 6-10 years (7.09±0.99%, n=1915; p<0.000001) (tab.
III). The duration of diabetes positively correlated with the HbA1c
value, and on average this increase was maintained at asmall
level of 0.1023/year (±95%CI 0.0855÷0.1191, p <0.000001).
Moreover, astatistically significant correlation was observed
between the HbA1c value and the child’s age at the moment
of testing –with every year, amean increase in the HbA1c level
by 0.1103 was noted (±95%CI 0.1009÷0.1198, p<0.000001).
Furthermore, asignificant increase in measurement dispersion
along with the child’s age is visible (p<0.000001).
HbA1c value below 7.5 and above 9% For the HbA1c value
below 7.5, the number of children and adolescents with astable
HbA1c level was 455(55.69%) vs. 362(44.31%) –4330 meas-
urements (55.63%) vs. 3453(44.37%), and for the HbA1c value
above 9%, these numbers were 110(13.46%) vs. 707(86.54%)
–1056 measurements (13.57%) vs. 6727(86.43%) respectively.
On the other hand, HbA1c values lower than or equal to 6.5%
were observed in agroup of 150children (18.36%).
HbA1c –in regions: Gdańsk, Łodź, Katowice
Individually for the Gdańsk, Łodź, and Katowice regions,
mean HbA1c values were: 8.27±1.77%, 7.78±1.47%, 7.33±1.45%
respectively, and differed significantly (p<0.000001) (tab. IV).
Asignificantly higher mean HbA1c value was noted among
the girls in comparison to boys (girls 8.45±1.92%, n=507; boys
8.09±1.59%, n=505; p=0.0013) in Gdańsk-G region only. Statis-
tically significant changes of HbA1C values in time (p=0.0002)
were observed in Łódź region only; the HbA1c value in 2006was
slightly higher than in the following years. As demonstrated
by the multi-factorial analysis conducted separately for each
Table II: Average HbA1c and its standard deviation within regions and age groups
Tabela II: Średnie stężenia HbA1c iodchylenie standardowe wzależności od regionu igrup wiekowych
Age group [years]
Grupa wiekowa [lata] Gdańsk Łódź Katowice All patients / Wszyscy pacjenci
HbA1c % n HbA1c % n HbA1c % n HbA1c % n
2-5 7.15±0.67 33 7.05±0.76 94 7.02±0.92 131 7.05±0.83 258
6-10 7.54±1.05 243 7.31±0.99 713 6.82±0.89 959 7.09±0.99 1915
11-19 8.56±1.90 736 7.97±1.58 2089 7.52±1.58 2785 7.82±1.66 5610
All patients / Wszyscy pacjenci 8.27±1.77 1012 7.78±1.47 2896 7.33±1.45 3875 7.62±1.54 7783
Table III: ANOVA table for multi-way analysis of variance with interactions
Tabela III. Wielokierunkowa analiza zuwzględnieniem korelacji ze zmiennymi (ANOVA)
Source / Źródło Sum of Squares / Średnia kwadratów d.f. Mean Squares / Średnia kwadratów F Prob>F
Age / Wiek 703.7 2 351.867 164.51 <0.0001
Gender / Płeć 6.3 1 6.261 2.93 0.0871
Region / Region 94.0 2 46.994 21.97 <0.0001
Year / Rok 5.9 3 1.966 0.92 0.4305
Age:gender / Wiek:płeć 0.4 2 0.187 0.09 0.9165
Age:region / Wiek:region 35.3 4 8.814 4.12 0.0025
Age:year / Wiek:rok 2.9 6 0.486 0.23 0.9681
Gender:region / Płeć:region 12.4 2 6.181 2.89 0.0557
Gender:year / Płeć:rok 0.8 3 0.278 0.13 0.9423
Region:year / Region:rok 30.2 6 5.034 2.35 0.0284

128
Pediatric Endocrinology, Diabetes and Metabolism 2012, 18, 4
Jarosz-Chobot P., Polańska J., Myśliwiec M. i wsp.
Wieloośrodkowa analiza wartości hemoglobiny glikowanej (HbA1c)...
significantly deteriorates metabolic control [4, 5, 19]. Dynamic
hormonal, emotional and social changes in the maturing body
are responsible for this well-known fact. The main causes are
the developing strong independence of the teenager, the teen-
ager’s rebellion against everyday rituals, experimenting with
risky behaviours or the lack of acceptance of the disease [19].
More than ahalf of all the patients in this study reached the tar-
get HbA1c values recommended by ISPAD (HbA1c <7.5%), while
only ca. 18% of the patients reached the values recommended
by Diabetes Poland (HbA1c ≤ 6.5%) [6]. In about 13.5% of the
children, HbA1c stayed above 9%. Proper metabolic control of
diabetes in accordance with the ISPAD guidelines was obtained
above all in the groups of the youngest and younger children
groups (HbA1c 7.05±0.5; 7.09±0.99%), i.e. those children who
still were under the control of their guardians [5]. These results
indicate the lowest percentage of patients with insufficient
diabetes control and the highest percentage of patients with
good diabetes control in comparison with the data from other
publications [8, 12, 17]. The above observations are aproof of
optimistic and effective changes in diabetes care in diabet-
ic children in Poland, similarly as in other countries. Further
multiannual, population observational studies will probably
answer the question to what extent this new policy will allow
to reduce the incidence of delayed diabetes complications and
prolong the survival of the currently treated children and ado-
lescents with diabetes [20]. Amultidirectional explanation of
the presented results is possible. On one hand, state-of-the art
technologies were introduced in Poland and became generally
accessible in 2002(purchases of personal insulin pumps by the
Foundation of the Great Orchestra of Christmas Charity, current-
ly by the National Health Fund). The progressively increasing
experience with and safety of insulin therapy intensification
translate into improved metabolic control. On the other hand,
it is worth noting that the target HbA1c value recommended by
Diabetes Poland (≤6.5%) for children of all age groups is signif-
icantly lower than the ISPAD or ADA guidelines [4-6]. Research-
region, age plays an important role in each of them (tab. III),
while the mean HbA1c value below 7.5 characterised the chil-
dren in two younger age groups in Katowice and Łódź regions,
and only the youngest children in Gdańsk region.
Discussion
Despite amarked improvement in the recent years, the
published results of multicentre analyses of metabolic control,
reflected in the HbA1c value for children and adolescents with
diabetes, in comparison with the recommended target values
of glycated haemoglobin are still unsatisfactory [8, 10-15]. Our
Polish example from 3university paediatric diabetes centres,
of arepresentative PolPeDiab group, is more optimistic and
indicates relatively good metabolic control in children and
adolescents (HbA1c 7.62±1.54%) with long-term type 1diabe-
tes (6.93±2.33 years) in comparison with data of other authors
of the last decade (for example, Rosenbauer 8.1%, de Beaufort
8.0, Gerstl 7.8%; Hanberger 8.3%, Vanelli 8.87%, Swift 8.2%) [8,
10, 12-14, 16]. Additionally, in contrast to this study, in the multi-
centre trials referred to above, also initial HbA1c values, and thus
often the values of the period of the patients’ remission, were
analysed. As aconsequence, these data are underestimated.
Only Gerst et al., the group of Hvidoere and Tonell et al. distin-
guish patients at one year or two years from the disease onset,
respectively [12, 16, 17]. In the first and second of the reports
described, the HbA1c value is 7.9% and 8.2%, respectively (2005)
[12, 16]. On the other hand, asimilar investigation of the HbA1c
value (7.6%) conducted by Tonell et al. is unfortunately, restrict-
ed only to asingle centre, conducted in arelatively small group
of children (152) and involves only aone-year follow-up period
(2007-2008) [17]. Similarly as in other analyses, the parameters
which significantly (strongly) contribute to achange of HbA1c
values are children’s age (puberty period), duration of diabetes
and the treatment centre [6, 12, 13, 17,18]. As confirmed by
numerous publications, in clinical practice, arriving at puberty
Table IV: Comparison of clinical parameters and HbA1c values in di erent regions
Tabela IV: Porównanie parametrów klinicznych stężeń HbA1c wróżnych regionach
Clinical parameter
Parametry kliniczne Katowice
Kregion / region K
(N=449)
Łódź
Lregion / region L
(N=372)
Gdańsk
Gregion / region G
(N=175)
ANOVA
p-value
wartość p
Age at disease onset [years]
Wiek zachorowania [lata] 8.37±3.57 7.78±3.46 7.64±3.32 0.014504
(K region differs from the other regions)
(region Króżni się odpozostałych regionów)
Current duration of disease [years]
Czas trwania choroby [w latach] 6.78±2.35 7.08±2.44 7.04±2.04 0.156391
Constant component HbA1c [%]
Stała wartość HbA1c7.34±1.25 7.76±1.24 8.28±1.60 <0.000001
(all regions differ pairwise)
(wszystkie regiony różnią się parami)
Number of HbA1c measurements in the follow-up period (n)
Liczba oznaczeń HbA1c wokresie obserwacji 8.73±3.56 7.98±2.80 5.86±1.80 <0.000001
(all regions differ pairwise)
(wszystkie regiony różnią się parami)
Follow-up time [years]
Okres obserwacji [lata] 2.42±0.95 2.32±0.86 2.75±0.74 <0.000001
(G region differs from the other regions)
(region Gróżni się od pozostałych regionów)
Percent of disease duration subject to follow-up [%]
Procent obserwacji zczasu trwania choroby 36.93±14.47 36.27±14.01 39.58±11.01 0.091374
Coefficient of variation CV [%]
Współczynnik zmienności 8.99±6.12 8.53±4.67 8.66±4.87 0.472780

129
Jarosz-Chobot P., Polańska J., Myśliwiec M. et al.
Multicenter cross-sectional analysis of values of glycated haemoglobin (HbA1c)...
ers of the Hvidoere group emphasise this factor as particularly
important for the attainment of the recommended targets
[16]. Aconfirmation of this concept is the relatively low (18%)
percent of Polish children attaining the values in the Diabetes
Poland guidelines, and at the same time consistent with that in
similar studies taking into account higher recommendations, i.e.
those of ADA or ISPAD. Another favourable factor indicated by
the authors is the care at large university centres conducted by
specialised diabetes management teams headed by apaedia-
trician specialised in diabetes care [21]. Moreover, in the Polish
educational system, there is an individual specialisation in dia-
betes care, covering all issues in this area, open for all qualified
paediatricians. In our analysis, the HbA1c values in girls and
boys did not differ, although regionally they were higher in girls
(Gdańsk-region). Many authors indicate atendency to higher
HbA1c values in girls [8, 10, 13], although there are also reports
stating its absence [15, 17, 21]. This may result from ahigher
overall HbA1c value in the populations discussed. An important
and repeatedly emphasised factor influencing the attainment
of target values of metabolic control are differences among
centres, also clearly visible in this analysis [10, 12, 13, 16, 21]. It
is difficult to define what these differences are based on, espe-
cially in the context of the above-discussed similar administra-
tive and organisational structure of diabetes care (including the
number and mean age of educational team members) within
PolPeDiab. Only personal experience and individual behaviours
of the educational diabetes team seem to play amajor role.
It may also be considered how many persons of the diabetes
team personnel still adopt the conservative approach and use
the previous target values of HbA1c, or whether there are dif-
ferences in education, evaluation and management strategy of
hypoglycaemia or in nutritional recommendations. Limitations
of this analysis include HbA1c measurements in 3different lab-
oratories, albeit with the use of the same methodology, with
similar normal ranges, and the lower number of children (HbA1c
measurements) at the Gdańsk-region, resulting from the adopt-
ed study criteria. On the other hand, the strength of this analysis
is the unique approach to evaluating HbA1c changes in chil-
dren with long-term type 1diabetes already after the remission
period (at 2years after the onset) at 3similar but independent
paediatric diabetes centres in one country.
Conclusions
In more than 50% of Polish children with longer T1DM
duration, the international target of glycaemic control (HbA1c)
is achieved; however, only 18% of them reached Polish national
target. Age, T1DM duration and centre-specific factors influence
the HbA1c values.
The study partially supported by NCN grant NN519579938 and
KNW-1-045/P/1/0.
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Received: 2012-11-20. Accepted: 2012-12-14.
Conflict of interests: none declared
Address for correspondence:
Przemysława Jarosz-Chobot MD, PhD
Śląski Uniwersytet Medyczny wKatowicach
Klinika Pediatrii, Endokrynologii iDiabetologii Dziecięcej
ul. Medyków 18, 40-752 Katowice, Poland
phone: (48 32) 20716 54; e-mail: pjarosz-chobot@sum.edu.pl