Impact of Body Weight on Blood Pressure With a Focus on Sex Differences

Abstract

INCREASED BLOOD pressure and hypertension are related to increased mortality and cardiovascular morbidity.^1-6 Blood pressure is well known to increase with age,^7-9 and age has been thought to be an independent cause of the increase.¹⁰ Several studies, however, show that this hypothesis is only valid in populations with a high intake of salt and fatty acids or a large increase in body weight by age.^11-15 A number of reports have elucidated the association between different characteristics (age, leisure habits, levels of physical activity, serum cholesterol levels, etc) and blood pressure change.^16-22 The majority of these reports conclude that attained weight and weight change are the strongest predictors of absolute blood pressure level and blood pressure change. This causal association is supported by studies showing that weight reduction decreases blood pressure and consequences of hypertension such as left ventricle hypertrophy.^23-26 Furthermore, blood pressure change is reported to be associated with serum lipid levels, fatty acid levels, salt intake, and alcohol consumption.^12,16,27 Although most studies on cardiovascular risk factors have focused on men, sex differences have been shown in the effects of changes in weight and blood pressure on cardiovascular mortality.²⁸ Differences between the sexes are present for other cardiovascular disease risk factors as well.^2,29,30 However, to our knowledge, no study has focused on sex differences in the effects of initial body weight and weight change on blood pressure change. Nor has there been a focus on the interacting effects of initial body weight and weight change on blood pressure change. Does the effect of weight change vary by initial body weight? As health problems due to obesity increase, investigations on effects of obesity and weight change should be a high priority for cardiovascular research in the coming years.