Dataset Information

Association of type 1 diabetes with month of birth among U.S. youth: The SEARCH for Diabetes in Youth Study.

ABSTRACT:

Objective

Seasonal environment at birth may influence diabetes incidence in later life. We sought evidence for this effect in a large sample of diabetic youth residing in the U.S.

Research design and methods

We compared the distribution of birth months within the SEARCH for Diabetes in Youth Study (SEARCH study) with the monthly distributions in U.S. births tabulated by race for years 1982-2005. SEARCH study participants (9,737 youth with type 1 diabetes and 1,749 with type 2 diabetes) were identified by six collaborating U.S. centers.

Results

Among type 1 diabetic youth, the percentage of observed to expected births differed across the months (P = 0.0092; decreased in October-February and increased in March-July). Their smoothed birth-month estimates demonstrated a deficit in November-February births and an excess in April-July births (smoothed May versus January relative risk [RR] = 1.06 [95% CI 1.02-1.11]). Stratifications by sex or by three racial groups showed similar patterns relating type 1 diabetes to month of birth. Stratification by geographic regions showed a peak-to-nadir RR of 1.10 [1.04-1.16] in study regions from the northern latitudes (Colorado, western Washington State, and southern Ohio) but no birth-month effect (P > 0.9) in study regions from more southern locations. Among type 2 diabetic youth, associations with birth month were inconclusive.

Conclusions

Spring births were associated with increased likelihood of type 1 diabetes but possibly not in all U.S. regions. Causal mechanisms may involve factors dependent on geographic latitude such as solar irradiance, but it is unknown whether they influence prenatal or early postnatal development.

SUBMITTER: Kahn HS

PROVIDER: S-EPMC2768213 | biostudies-literature | 2009 Nov

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Association of type 1 diabetes with month of birth among U.S. youth: The SEARCH for Diabetes in Youth Study.

Kahn Henry S HS Morgan Timothy M TM Case L Douglas LD Dabelea Dana D Mayer-Davis Elizabeth J EJ Lawrence Jean M JM Marcovina Santica M SM Imperatore Giuseppina G

Diabetes care 20090812 11

<h4>Objective</h4>Seasonal environment at birth may influence diabetes incidence in later life. We sought evidence for this effect in a large sample of diabetic youth residing in the U.S.<h4>Research design and methods</h4>We compared the distribution of birth months within the SEARCH for Diabetes in Youth Study (SEARCH study) with the monthly distributions in U.S. births tabulated by race for years 1982-2005. SEARCH study participants (9,737 youth with type 1 diabetes and 1,749 with type 2 diab ...[more]

PMID: 19675199

Similar Datasets

Project description:ObjectiveLittle is known about arsenic and diabetes in youth. We examined the association of arsenic with type 1 and type 2 diabetes in the SEARCH for Diabetes in Youth Case-Control (SEARCH-CC) study. Because one-carbon metabolism can influence arsenic metabolism, we also evaluated the potential interaction of folate and vitamin B12 with arsenic metabolism on the odds of diabetes.Research design and methodsSix hundred eighty-eight participants <22 years of age (429 with type 1 diabetes, 85 with type 2 diabetes, and 174 control participants) were evaluated. Arsenic species (inorganic arsenic [iAs], monomethylated arsenic [MMA], dimethylated arsenic [DMA]), and one-carbon metabolism biomarkers (folate and vitamin B12) were measured in plasma. We used the sum of iAs, MMA, and DMA (∑As) and the individual species as biomarkers of arsenic concentrations and the relative proportions of the species over their sum (iAs%, MMA%, DMA%) as biomarkers of arsenic metabolism.ResultsMedian ∑As, iAs%, MMA%, and DMA% were 83.1 ng/L, 63.4%, 10.3%, and 25.2%, respectively. ∑As was not associated with either type of diabetes. The fully adjusted odds ratios (95% CI), rescaled to compare a difference in levels corresponding to the interquartile range of iAs%, MMA%, and DMA%, were 0.68 (0.50-0.91), 1.33 (1.02-1.74), and 1.28 (1.01-1.63), respectively, for type 1 diabetes and 0.82 (0.48-1.39), 1.09 (0.65-1.82), and 1.17 (0.77-1.77), respectively, for type 2 diabetes. In interaction analysis, the odds ratio of type 1 diabetes by MMA% was 1.80 (1.25-2.58) and 0.98 (0.70-1.38) for participants with plasma folate levels above and below the median (P for interaction = 0.02), respectively.ConclusionsLow iAs% versus high MMA% and DMA% was associated with a higher odds of type 1 diabetes, with a potential interaction by folate levels. These data support further research on the role of arsenic metabolism in type 1 diabetes, including the interplay with one-carbon metabolism biomarkers.

Dataset Information

Association of type 1 diabetes with month of birth among U.S. youth: The SEARCH for Diabetes in Youth Study.

Objective

Research design and methods

Results

Conclusions

Publications

Association of type 1 diabetes with month of birth among U.S. youth: The SEARCH for Diabetes in Youth Study.

Similar Datasets

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