Insulin resistance or compensatory hyperinsulinemia has been associated with hypertension and dyslipidemia in cross-sectional studies. In contrast, evidence from prospective population-based studies, which could establish the time order of the relationship, is sparse and inconsistent. Therefore, we investigated the associations of hyperinsulinemia with the incidence of hypertension and dyslipidemia in the Kuopio Ischemic Heart Disease Risk Factor Study, a population-based 4-year follow-up study of middle-aged men from eastern Finland. Out of 975 men who had no diabetes, 543 had resting systolic blood pressure (sBP) of or =1.0 mmol/l at baseline. In logistic regression models adjusted for age, baseline resting blood pressure, baseline lipids, obesity, weight change, and other risk factors, men with hyperinsulinemia (fasting insulin in the highest quintile, > or =12.0 mU/l) at baseline had a 2.0-fold (95% CI 1.1-3.5, P = 0.025) incidence of hypertension (sBP of > or =165 or dBP of > or =95 mmHg), a 2.1-fold (95% CI 1.3-3.4, P = 0.002) incidence of dyslipidemia (serum HDL cholesterol of or =2.3 mmol/l), and a 2.6-fold (95% CI 1.1-6.3, P = 0.028) incidence of the combination of these disorders in 4 years, compared with normoinsulinemic men. These findings demonstrate the role of hyperinsulinemia in incident hypertension and dyslipidemia and suggest that both hypertension and dyslipidemia are associated with insulin metabolism disturbance, independently of obesity and body weight.