Impact of age on the association between 24-h ambulatory blood pressure measurements and target organ damage

OBJECTIVE: The aim of this study was to evaluate the impact of age on the associations between hemodynamic components derived from 24-h ambulatory blood pressure (24-h ABPM) and target organ damage, in apparently healthy, nonmedicated individuals. METHODS: Twenty-four-hour ABPM and target organ damage (left ventricular mass index, pulse wave velocity, urine albumin : creatinine ratio and carotid atherosclerotic plaques) were evaluated in 1408 individuals. Associations were examined in regression models, stratified for age [middle-aged (41 or 51 years) or elderly (61 or 71 years)], and adjusted for sex, smoking status, and total-cholesterol. RESULTS: In middle-aged individuals, an increase of 10 mmHg in 24-h SBP was independently associated with an increase of 3.8 (2.7-4.8) g/m in LVMI. The effect was nearly doubled in the elderly subgroup, where the same increase resulted in an increase in LVMI of 6.3 (5.0-7.6) g/m (P for interaction 0.26). CONCLUSION: Age enhances the associations between hemodynamic components obtained from 24-h ABPM and measures of arterial stiffness, microvascular damage, and cardiac structure, but not atherosclerosis.