BIRTH SIZE AND RISK OF INSULIN-DEPENDENT DIABETES-MELLITUS (IDDM)

A case-control study was conducted to test the hypotheses that birth s ize is increased in infants who develop IDDM in childhood and that bir th size differs by diagnosis age. Cases were non-Hispanic white (NHW) children randomly selected from the Colorado IDDM Registry (n = 221). Controls (n = 197) were NHW children frequency-matched to cases by age -group and gender. Self-administered questionnaires collected birth si ze and demographic data. There were no significant univariate differen ces in birth weight (cases 3303.0 g; controls, 3346.1 g; P = 0.40), bi rth length (cases, 50.8 cm; controls, 51.2 cm; P = 0.28), or ponderal index (cases, 2.52; controls, 2.49;P = 0.92). The case/control odds ra tio (OR) controlling for gender, maternal education, and birth place w as 1.0 (95% confidence interval (CI) 0.4, 2.5) for the highest categor y of birth weight compared to the lowest. There were no statistically significant case/control differences in ponderal index (highest to low est category OR = 1.1; 95% CI 0.6, 2.0) or birth length (1 cm increase OR, 1.0; 95% CI 0.9, 1.2). Similarly, analysis by age-at-diagnosis gr oups revealed no significant differences, suggesting that birth size d oes not reveal prenatal diabetogenic influences.