Patients with adult onset growth hormone deficiency have a decreased life expectancy owing to an increased mortality from cardiovascular disease. In the present study, 104 subjects (66 men and 38 women, aged 22-74 years) with growth hormone deficiency and with adequate replacement therapy with glucocorticoids, thyroid hormones and gonadal steroids were studied with respect to known risk factors for cardiovascular disease. For comparison, data from a population study, "the MONICA study", were obtained. The patients had a significantly higher body mass index compared to controls (p < 0.001). Serum triglyceride concentration was higher (p < 0.001) but there was no difference in serum total cholesterol concentration. Serum high-density lipoprotein cholesterol concentration was lower (p < 0.001) in the patients. There was no difference in the prevalence of diabetes mellitus. The prevalence of treated hypertension was higher (p < 0.05) in the patients but the prevalence of smoking was lower (p < 0.001). Even after taking the increased body mass index into consideration, the changes in the prevalence of treated hypertension (p < 0.05) and in the serum concentrations of triglycerides (p < 0.05) and high-density lipoprotein concentrations (p < 0.001) remained. These results indicate that growth hormone deficiency alters lipoprotein metabolism and increases the risk for development of hypertension, which in turn might contribute to the increased risk for cardiovascular disease.