DIET AND PHYSICAL-ACTIVITY AS DETERMINANTS OF HYPERINSULINEMIA - THE ZUTPHEN ELDERLY STUDY

The relation of dietary factors and physical activity to hyperinsuline mia was examined in 389 men aged 70-89 years who participated in the Z utphen Elderly Study in 1990. Information about the usual diet was obt ained using a cross-check dietary history, and habitual physical activ ity was assessed using a validated questionnaire. Known and newly diag nosed diabetic patients were excluded from this study, since serum ins ulin and C-peptide levels are indicators of insulin resistance and hyp erinsulinemia in nondiabetics only. Insulin levels during the oral glu cose tolerance test were lowest in men with the highest physical activ ity. This inverse association was independent of age, body mass index, the ratio of subscapular to triceps skinfold thickness, cigarette smo king, and energy intake (p < 0.001). In addition, insulin levels were inversely associated with the intake of dietary fiber and polyunsatura ted fatty acids, which could not be accounted for by variables such as energy intake, body mass index, physical activity, prescribed diets, or the presence of coronary heart disease. In contrast, insulin levels increased with the increasing intake of saturated fatty acids and alc ohol. The fasting C-peptide level was independently associated with th e intake of total fat, saturated and monounsaturated fatty acids, and alcohol, whereas an inverse relation with the intake of total carbohyd rates and dietary fiber was seen. Besides overweight, physical activit y and dietary factors such as the intake of fatty acids, fiber, carboh ydrates, and alcohol, were independently associated with hyperinsuline mia and insulin resistance. Therefore, these behavioral factors may pa rtly determine the occurrence of non-insulin-dependent diabetes mellit us and coronary heart disease and play a role in the prevention of the se disorders.