The study participants were chosen through a population-based recruitment and where a random sample of 1000 men (55-65 years old) living in Oulu, Finland was drawn from the Finnish Population Register. The subjects were screened by telephone interviews for eligibility for the study. Eligible attendees measured their blood pressure at home for a week according to the recommendations of the European Society of Hypertension. Based on these measurements they were classified either to hypertensive (systolic blood pressure ≥135 and/or diastolic blood pressure ≥85 mmHg) or normotensive (blood pressure <135/85mmHg).(16) The exclusion criteria was the presence of coronary heart or respiratory diseases, use of antihypertensive drugs for any indication, an average home BP ≥175/105 mm Hg, and failed home BP measurements. We aimed at recruiting a 2:1 ratio of hypertensive and normotensive subjects. The final study group consisted of 56 hypertensive and 35 normotensive middle-aged men.