Behavior, heredity, and diabetes in college alumnae.

Objective: Diabetes has been increasing in incidence and prevalence in the United States. Physical activity and exercise have been shown to lower the risk of noninsulin-dependent diabetes (NIDD), and family history and genetic factors are associated with both insulin-dependent diabetes (IDD) (type 1) and NIDD. The objective of this paper is to examine risk factors for diabetes in female college graduates as part of a study designed to determine the long-term health of former college athletes compared with nonathletes. The study was first conducted in 1981-1982, and a follow-up study was conducted in 1996-1997.

Methods: The subjects for this paper are 3940 college alumnae (1945 former athletes and 1995 nonathletes), who participated in the follow-up study by responding to a self-administered questionnaire on medical history, health, family history, and behavioral practices.

Results: About 1.3% of the women reported physician-diagnosed diabetes, 0.9% of the former athletes, and 1.7% of the nonathletes. Former athletes had a significantly lower risk of NIDD, with an age-adjusted odds ratio (OR) of 0.41, 95% confidence level (CL) 0.2, 0.9. IDD was associated with a history of paternal diabetes (OR = 4.7, 95% CL 1.5, 14.9) and also with a history of diabetes in siblings (OR = 6.7, 95% CL 1.5, 30.1). NIDD was associated with a history of maternal diabetes (OR = 8.0, 95% CL 3.6, 17.8). Behavioral factors showed no association with IDD but were inversely associated with NIDD. The OR for being an athlete was 0.4, 95% CL 0.2, 0.9; for current regular exercise, OR = 0.4, 95% CL 0.2, 0.9; low body mass index (BMI) compared to high BMI, OR = 0.2, 95% CL 0.05, 0.60.

Conclusions: The findings that IDD is associated with paternal diabetes and that NIDD may be maternally transmitted are not widely known, although the mode of transmission of diabetes is receiving increasing attention in the medical and genetic literature. This study confirms that modifiable behavioral practices, such as physical activity and weight control (i.e., optimal BMI), reduce the risk of NIDD.