Ejm. Feskens et al., DIET AND PHYSICAL-ACTIVITY AS DETERMINANTS OF HYPERINSULINEMIA - THE ZUTPHEN ELDERLY STUDY, American journal of epidemiology, 140(4), 1994, pp. 350-360
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.