We recently reported that female patients with hypopituitarism receiving controlled thyroid and steroid hormone substitution, but without GH replacement, had a more than 2-fold increase in cardiovascular mortality compared to the general population. In the present study we investigated the incidence of cardiovascular disease as well as the prevalence of cardiovascular risk factors in 33 females with hypopituitarism for 6-46 yr (median, 18) compared to those in 33 control subjects recruited from the general population in the same geographical area and matched for sex, age, smoking habits, educational level, and residence location. The patients were with a very high probability GH deficient, as 29 had subnormal serum insulin-like growth factor I levels, and the other 4 were GH deficient, as assessed by an insulin tolerance test. The incidence of cardiovascular disease was significantly higher among the hypopituitary patients (incidence ratio, 3.7; 95% confidence interval, 1.2-11.3), and the consumption of cardioactive drugs was also significantly higher (P = 0.002). Hypopituitary patients had a lower degree of physical exercise during their spare time (P = 0.02), a higher waist/hip ratio (P = 0.01), lower high density lipoprotein cholesterol (P = 0.002), and higher low density/high density lipoprotein ratio (P = 0.009). Furthermore, the patients had a significantly increased left atrium size (P = 0.05), but no difference was observed for other cardiac measures. In the patients, serum insulin-like growth factor I levels significantly correlated with left ventricular mass index (r = 0.48; P = 0.006), suggesting that GH has a strong impact on cardiac size. More episodes of bradycardia (P = 0.05), but no increased occurrence of extrasystolies, were encountered in the patients during 24-h continuous electrocardiogram monitoring. Carotid artery intima-media thickness and plaque numbers did not differ between patients and controls. In conclusion, hypopituitary females exhibit an increased incidence of cardiovascular disease, higher cardioactive drug consumption, and an increased prevalence of cardiovascular risk factors. The increased cardiovascular morbidity could not be ascribed to inadequate estrogen or thyroid hormone treatment, and unsubstituted GH deficiency is probably an important contributing factor.