ASSOCIATION OF LOW RENIN ACTIVITY WITH UNCONTROLLED NIGHT-TIME AND MORNING BLOOD PRESSURE AS RESIDUAL RISK IN GOOD BLOOD PRESSURE CONTROLLED ELDERLY SUBJECTS

Abstract

Objective: To achieve optimal nighttime blood pressure (BP) and morning BP is often challenging especially in elderly subjects. Although low renin revels are seen especially in the elderly, data are sparse about the association between renin-angiotensin-aldosterone (RAA) system and uncontrolled nighttime and morning BP. Design and method: Ambulatory BP (ABP) was assessed in 315 Minamisanriku Study participants with aldosterone and plasma renin activity (PRA). Multivariable linear and logistic regression analyses were used to analyze the association of aldosterone and PRA with awake and asleep ABP and hypertension defined by ABP, adjusting for important confounders included the use of RAA inhibitors. We divided them into non-elderly (<80 years, n = 164) and elderly group (>80 years, n = 151). Results: In total participants, 95% was treated hypertension and average 24-hour BP was 114.2±8.9/67.5±5.9 mmHg. The prevalence of uncontrolled 24-hour (>130 mmHg), daytime (>135 mmHg), nighttime (>120 mmHg) and morning systolic BP (SBP) (>135 mmHg) was 5.6%, 7.4%, 8.6%, 26.8%, respectively. In elderly group, Lower log-PRA was associated with higher 24-hour, daytime, nighttime, and SBP (all P<0.01) after adjusted confounders. These associations were also observed in non-elderly group except for nighttime and morning SBP. Lower log-aldosterone was associated with higher 24-hour and daytime SBP only in elderly group (both P<0.01). A 1-unit higher log-PRA was associated with lower odds of uncontrolled nighttime SBP (odds ratio [OD] 0.19 [95%CI, 0.06-0.64) and uncontrolled morning SBP (OR, 0.43 [95%CI, 0.21-0.91]) but not in uncontrolled 24-hour and daytime SBP in elderly group, while these findings were not seen in non-elderly group. Similar results were observed in log-aldosterone. There was no association between aldosterone/PAC ratio and the presence of uncontrolled ABP. Conclusions: Suppressed renin activity and aldosterone were associated with uncontrolled nighttime and morning SBP in treated and good 24-hour BP controlled elderly population. Even in good 24-hour BP, low renin activity may be associated with residual ABP risk in elderly population.