Within-visit variability of blood pressure and all-cause and cardiovascular mortality among US adults

Abstract

The association between within-visit variability of systolic blood pressure (SBP) and diastolic blood pressure (DBP) and all-cause and cardiovascular (CVD) mortality was examined using the Third National Health and Nutrition Survey (n=15,317). Three SBP and DBP readings were taken by physicians during a single medical evaluation. Within-visit variability for each participant was defined using the standard deviation of SBP and DBP across these measurements. Mortality was assessed over 14 years (n=3848 and n=1684 deaths from all causes and CVD, respectively). After age, sex, and race-ethnicity adjustment, the hazard ratios (95% confidence intervals) for all-cause mortality associated with the 4 highest quintiles of within-visit standard deviation of SBP (2.00-2.99 mm Hg, 3.00-3.99 mm Hg, 4.00-5.29 mm Hg, and ≥5.30 mm Hg) compared with participants in the lowest quintile of within-visit standard deviation of SBP (<2.0 mm Hg) were 1.04 (0.87-1.26), 1.09 (0.92-1.29), 1.06 (0.88-1.28), and 1.13 (0.95-1.33), respectively (P=.136). The analogous hazard ratios for CVD mortality were 0.95 (0.69-1.32), 0.96 (0.67-1.36), 0.95 (0.74-1.23), and 1.04 (0.80-1.35), respectively (P=.566). No association with mortality was present after further adjustment and when modeling within-visit standard deviation of SBP as a continuous variable. Standard deviation of DBP was not associated with mortality.

Figure FIGURE

Multivariable‐adjusted association between within‐visit variability (standard deviation [SD]) of systolic blood pressure from the Third Report of the National Health and Nutrition Examination Survey (NHANES III) mobile examination center visit and all‐cause (top panel) and cardiovascular mortality (bottom panel). Fully adjusted includes age, sex, race‐ethnicity, physical inactivity, current smoking, body mass index, total cholesterol, diabetes mellitus, estimate glomerular filtration rate <60 mL/min/1.73 m², albuminuria ≥30 mg/g, C‐reactive protein ≥3 mg/L, history of myocardial infarction, history of stroke, mean systolic blood pressure (SBP), pulse pressure, and use of angiotensin‐converting enzyme inhibitors, β‐blockers, calcium channel blockers, or thiazide‐type diuretics.