Prevalence and clinical correlates of hypotensive episodes among older hypertensive adults undergoing 24-h ambulatory blood pressure monitoring

Objective: Older adults have increased susceptibility to hypotension. Hypotensive episodes have a negative prognostic impact at old age, being associated with adverse events such as syncope, falls and injuries, which impair quality of life and functional autonomy. 24-hour ambulatory blood pressure monitoring (ABPM) is a useful diagnostic tool to detect hypotension, although it is rarely used for this purpose. The present study aimed at assessing the prevalence and the clinical variables associated with hypotensive episodes on ABPM among older hypertensive adults. Design and method: prospective observational study involving hypertensive patients aged 75 or older evaluated at two outpatient clinics of Careggi Hospital, Florence, Italy. All participants underwent a comprehensive geriatric assessment, office blood pressure measurement and ABPM. Hypotensive episodes were defined as single daytime systolic blood pressure (SBP) measures <90 mmHg. Clinical variables associated with hypotensive episodes were investigated using multivariable logistic regression. Results: Among 123 participants (mean age 81 years, 59% female), the 16% showed hypotensive episodes on ABPM. Patients with hypotensive episodes were older (84±5 vs 81±4 years, p = 0.002), had a higher prevalence of dementia (50% vs 26%, p = 0.034) and received a higher number of daily medications (8[6-10] vs 6 [5-9], p = 0.036). Moreover, they showed lower 24h-SBP (139±15 vs 149±15, p = 0.008), daytime SBP (141±15 vs 151±15, p = 0.005) and night-time SBP (129±18 vs 140±20, p = 0.005) and a higher prevalence of white coat effect (30% vs 12%, p = 0.034). At multivariable analysis, hypotensive episodes were associated with use of angiotensin-receptor blockers (ARBs, OR 24.325, p = 0.002), independently of age, sex, dementia, 24h-SBP and number of medications. By contrast, use of ACE-inhibitors (OR 0.719, p = 0.013) and thiazide diuretics (OR 0.978, p = 0.048) were inversely associated with hypotension on ABPM. Conclusions: Hypotensive episodes are a common finding in older adults undergoing ABPM. Hypotensive episodes more frequently occur in patients with lower SBP and white coat effect and are independently associated with ARBs use. ACE-inhibitors and thiazides are inversely associated with hypotensive episodes on ABPM.