 2. Is the risk of developing diabetes among siblings of early-onset type 2 or mixed cases equivalent to that for siblings of type 1 patients? Which characteristics are most predictive of risk? Hypothesis 2. Changes in the epidemiologic parameters of childhood diabetes over the past 2 decades are directly related to changes in the prevalence of risk factors for both type 1 and type 2 diabetes, including obesity, physical inactivity, and perinatal exposures. 