Birthweight and the risk of childhood-onset type 1 diabetes: a meta-analysis of observational studies using individual patient data

• Published in: Diabetologia Vol. 53; no. 4; pp. 641 - 651
• Main Authors: Cardwell, C. R., Stene, L. C., Joner, G., Davis, E. A., Cinek, O., Rosenbauer, J., Ludvigsson, J., Castell, C., Svensson, J., Goldacre, M. J., Waldhoer, T., Polanska, J., Gimeno, S. G. A., Chuang, L.-M., Parslow, R. C., Wadsworth, E. J. K., Chetwynd, A., Pozzilli, P., Brigis, G., Urbonaitė, B., Šipetić, S., Schober, E., Ionescu-Tirgoviste, C., de Beaufort, C. E., Stoyanov, D., Buschard, K., Patterson, C. C.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01-04-2010; Springer; Springer Nature B.V
• Subjects: Adolescent; Age of Onset; Biological and medical sciences; Birth Order; Birth Weight; Birthweight; Child; Child, Preschool; Childrens health; Diabetes; Diabetes Mellitus, Type 1 - epidemiology; Diabetes. Impaired glucose tolerance; Endocrine pancreas. Apud cells (diseases); Endocrinopathies; Epidemiology; Etiopathogenesis. Screening. Investigations. Target tissue resistance; Female; Gestational Age; Hospitals; Human Physiology; Humans; Infant; Infant, Newborn; Internal Medicine; Maternal Age; Medical research; Medical sciences; MEDICIN; MEDICINE; Medicine & Public Health; Meta-analysis; Metabolic Diseases; Observational studies; Pediatrics; Pregnancy; Public health; Risk Factors; Type 1 diabetes mellitus; Denmark; Austria; United Kingdom > UK; Norway; Luxembourg; Epidemiology; Risk factors; Birthweight; Meta-analysis; Type 1 diabetes mellitus; Endocrinopathy; Human; Immunopathology; Type 1 diabetes; Risk factor; Autoimmune disease; Birth weight
• ISSN: 0012-186X; 1432-0428
• DOI: 10.1007/s00125-009-1648-5

Aims/hypothesis
We investigated whether children who are heavier at birth have an increased risk of type 1 diabetes.
Methods
Relevant studies published before February 2009 were identified from literature searches using MEDLINE, Web of Science and EMBASE. Authors of all studies containing relevant data were contacted and asked to provide individual patient data or conduct pre-specified analyses. Risk estimates of type 1 diabetes by category of birthweight were calculated for each study, before and after adjustment for potential confounders. Meta-analysis techniques were then used to derive combined ORs and investigate heterogeneity between studies.
Results
Data were available for 29 predominantly European studies (five cohort, 24 case–control studies), including 12,807 cases of type 1 diabetes. Overall, studies consistently demonstrated that children with birthweight from 3.5 to 4 kg had an increased risk of diabetes of 6% (OR 1.06 [95% CI 1.01–1.11];
p
 = 0.02) and children with birthweight over 4 kg had an increased risk of 10% (OR 1.10 [95% CI 1.04–1.19];
p
 = 0.003), compared with children weighing 3.0 to 3.5 kg at birth. This corresponded to a linear increase in diabetes risk of 3% per 500 g increase in birthweight (OR 1.03 [95% CI 1.00–1.06];
p
 = 0.03). Adjustments for potential confounders such as gestational age, maternal age, birth order, Caesarean section, breastfeeding and maternal diabetes had little effect on these findings.
Conclusions/interpretation
Children who are heavier at birth have a significant and consistent, but relatively small increase in risk of type 1 diabetes.