Dataset Information

HbA(1c) levels in schoolchildren with type 1 diabetes are seasonally variable and dependent on weather conditions.

ABSTRACT:

Aims/hypothesis

We evaluated seasonal HbA(1c) changes in children with type 1 diabetes and its relation with measures of weather conditions.

Methods

HbA(1c) changes over more than 3 years were evaluated in type 1 diabetic patients who were younger than 18 years and had diabetes duration of more than 12 months, and correlated with measures of weather conditions (ambient temperature, hours of sunshine and solar irradiance). After comparison of autocorrelation patterns, patterns of metabolic control and meteorological data were evaluated using Spearman rank correlation.

Results

A total of 3,935 HbA(1c) measurements in 589 school (? 7 years) and 88 preschool (<7 years) children were analysed. Mean (± SD) HbA(1c) level for the whole study period was 7.65 ± 1.12%. The lowest HbA(1c) levels were observed in late summer and the highest in winter months, with differences consistently exceeding 0.44%. Autocorrelation analysis of HbA(1c) levels in schoolchildren showed a sine-wave pattern with a cycle length of roughly 12 months, which mirrored changes in ambient temperature. Strong negative correlations of HbA(1c) with ambient temperature (R =?-0.56; p = 0.0002), hours of sunshine (R=?-0.52; p = 0.0007) and solar irradiance (R =?-0.52; p = 0.0006) were present in schoolchildren, but not in preschoolers (p ? 0.29 for each correlation).

Conclusions/interpretation

Seasonal changes of HbA(1c) levels in schoolchildren with type 1 diabetes are a significant phenomenon and should be considered in patient education and diabetes management. They may potentially affect the results of clinical trials using HbA(1c) levels as their primary outcome, as well as HbA(1c)-based diagnosis of diabetes.

SUBMITTER: Mianowska B

PROVIDER: S-EPMC3052478 | biostudies-literature | 2011 Apr

REPOSITORIES: biostudies-literature

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Publications

HbA(1c) levels in schoolchildren with type 1 diabetes are seasonally variable and dependent on weather conditions.

Mianowska B B Fendler W W Szadkowska A A Baranowska A A Grzelak-Agaciak E E Sadon J J Keenan H H Mlynarski W W

Diabetologia 20101225 4

<h4>Aims/hypothesis</h4>We evaluated seasonal HbA(1c) changes in children with type 1 diabetes and its relation with measures of weather conditions.<h4>Methods</h4>HbA(1c) changes over more than 3 years were evaluated in type 1 diabetic patients who were younger than 18 years and had diabetes duration of more than 12 months, and correlated with measures of weather conditions (ambient temperature, hours of sunshine and solar irradiance). After comparison of autocorrelation patterns, patterns of m ...[more]

PMID: 21188352

Similar Datasets

Project description:Aims/hypothesisThe aim of the study was to evaluate longitudinal associations between HbA1c levels, diabetes status and subsequent cognitive decline over a 10 year follow-up period.MethodsData from wave 2 (2004-2005) to wave 7 (2014-2015) of the English Longitudinal Study of Ageing (ELSA) were analysed. Cognitive function was assessed at baseline (wave 2) and reassessed every 2 years at waves 3-7. Linear mixed models were used to evaluate longitudinal associations.ResultsThe study comprised 5189 participants (55.1% women, mean age 65.6 ± 9.4 years) with baseline HbA1c levels ranging from 15.9 to 126.3 mmol/mol (3.6-13.7%). The mean follow-up duration was 8.1 ± 2.8 years and the mean number of cognitive assessments was 4.9 ± 1.5. A 1 mmol/mol increment in HbA1c was significantly associated with an increased rate of decline in global cognitive z scores (-0.0009 SD/year, 95% CI -0.0014, -0.0003), memory z scores (-0.0005 SD/year, 95% CI -0.0009, -0.0001) and executive function z scores (-0.0008 SD/year, 95% CI -0.0013, -0.0004) after adjustment for baseline age, sex, total cholesterol, HDL-cholesterol, triacylglycerol, high-sensitivity C-reactive protein, BMI, education, marital status, depressive symptoms, current smoking, alcohol consumption, hypertension, CHD, stroke, chronic lung disease and cancer. Compared with participants with normoglycaemia, the multivariable-adjusted rate of global cognitive decline associated with prediabetes and diabetes was increased by -0.012 SD/year (95% CI -0.022, -0.002) and -0.031 SD/year (95% CI -0.046, -0.015), respectively (p for trend <0.001). Similarly, memory, executive function and orientation z scores showed an increased rate of cognitive decline with diabetes.Conclusions/interpretationSignificant longitudinal associations between HbA1c levels, diabetes status and long-term cognitive decline were observed in this study. Future studies are required to determine the effects of maintaining optimal glucose control on the rate of cognitive decline in people with diabetes.

Dataset Information

HbA(1c) levels in schoolchildren with type 1 diabetes are seasonally variable and dependent on weather conditions.

Aims/hypothesis

Methods

Results

Conclusions/interpretation

Publications

HbA(1c) levels in schoolchildren with type 1 diabetes are seasonally variable and dependent on weather conditions.

Similar Datasets

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