RESUMEN
Pure systolic hypertension (PSH) is mainly observed in subjects over 60 years of age, and it is always due to a loss of compliance of the greater arteries. Blood pressure itself is partly responsible for loss of compliance, but other factors have been suggested. We have investigated this matter in a study of 3,388 subjects aged from 20 to 69 years. In a first stage, PSH patients (systolic BP greater than or equal to 160; diastolic BP less than 95 mmHg), aged from 50 to 59 years, were compared with normotensive subjects (systolic BP less than 140; diastolic BP less than 95 mmHg) and with other types of hypertensive patients with regard to cigarette smoking, alcohol consumption, obesity and plasma cholesterol, triglycerides, gamma-GT, glucose and uric acid levels. Several of these variables were significantly higher in all hypertensive patients than in normotensive subjects, but cigarette smoking and gamma-GT levels were predominantly or exclusively higher in PSH patients. In a second stage, correlations between differential BP and the variables listed above were studied in subjects with two levels of diastolic BP: 70-79 and 80-89 mmHg, thus taking into account all degrees between normal BP and PSH proper. Weakly positive correlations were found with alcohol consumption, plasma gamma-GT and glucose levels, and with percentages of smokers or ex-smokers. It is therefore conceivable that in addition to BP itself other factors, such as alcohol consumption, cigarette smoking and hyperglycaemia, contribute to the loss of arterial compliance progressively leading to pure systolic hypertension.