Perinatal and neonatal determinants of childhood type 1 diabetes - A case-control study in Yorkshire, UK

OBJECTIVE - To identify environmental factors that exert their effect in th e perinatal and neonatal period and influence the subsequent onset of insul in dependent (type 1) diabetes during childhood. RESEARCH DESIGN AND METHODS - A population-based case-control study of data abstracted from the hospital obstetric and neonatal records of 196 childre n with type 1 diabetes and 325 age- and sex-matched control subjects. Analy sis of matched sets by conditional logistic regression was conducted for a range of perinatal and neonatal factors. RESULTS - A significantly raised risk was observed for illnesses in the neo natal period (OR 1.61, 95% CI 1.06-2.44), the majority of which were infect ions and respiratory difficulties. Exclusive breast feeding as the initial feeding method was significantly protective (OR 0.65, 95% CI 0.45-0.94). Th ere were no significant associations with high- or low-birth weight, being firstborn or small-for-dates. All factors significant (5% level) for the en tire dataset, that is, maternal age, type 1 diabetes in mothers, preeclamps ia, delivery by cesarean section, neonatal illnesses, and initial breast fe eding were modeled and the OR remained significant for all variables other than cesarean section. CONCLUSIONS - The findings are based on medical record data that cannot be subject to biased recall of mothers. Neonatal illnesses increased and initi al breast feeding decreased the risk of childhood type 1 diabetes. Further determinants of risk are mothers with type 1 diabetes, older mothers, and p reeclampsia during pregnancy.