Systolic Blood Pressure and Vascular Disease in Men Aged 65 Years and over the HIMS (Health in Men Study)

Abstract

There is uncertainty about the relation between blood pressure and vascular disease at older age. We assessed the association of systolic blood pressure (SBP) and major vascular events in a prospective cohort study of 7564 men aged 65 to 94 years, recruited in 1996-1999 from the general population in Perth, Western Australia. SBP was measured at baseline and again at resurvey in 2001-2004. Participants were monitored for fatal and nonfatal vascular events. To limit the effect of reverse causality, analyses were restricted to men without previous vascular disease at baseline. Hazard ratios were estimated by Cox regression, with adjustment for age and education (further adjustment did not materially change the associations). During a mean follow-up of 11 years, there were 1557 major vascular events. Continuous log-linear associations were found between usual SBP and risk of major vascular events throughout the SBP range examined (145-170 mm Hg). Overall, 10 mm Hg higher usual SBP was associated with ≈20% higher risk of major vascular events (hazard ratio, 19%; 95% confidence interval, 13%-26%; mean age at event 80 years). There was evidence of positive associations with both ischemic heart disease and stroke and effect modification by age, with shallower associations at older ages. Even at 85 to 94 years, however, there was evidence of a positive association: 10 mm Hg higher usual SBP was associated with 14% (95% confidence interval, 1%-30%) higher risk of major vascular events.