Mean arterial pressure is better at predicting future metabolic syndrome in the normotensive elderly: a prospective cohort study in Taiwan

Objective: To compare four different blood pressure (BP) measurements-systolic BP (SBP), diastolic BP (DBP), mean arterial pressure (MAP), and pulse pressure (PP)-in predicting future metabolic syndrome (MetS) among the normotensive elderly population, and to estimate the optimal cutoff value of the best single measurement for clinical practice.

Methods: A total of 2782 non-medicated participants aged ≥ 60 years were enrolled in a standard health examination program in Taiwan from January 2004 to December 2013. Two thirds of the participants were randomly designated as the training group (n=1855) and the other one third as the validation group (n=927). The mean follow-up time was 3.60 years for both the training and validation groups. MAP and PP were calculated from SBP and DBP.

Results: SBP, DBP, and MAP were associated with future MetS, whereas PP was not. MAP had the largest hazard ratio in Cox regression (men 1.342 [95% CI 1.158-1.555] and women 1.348 [95% CI 1.185-1.534] in the training group; men 1.640 [95% CI 1.317-2.041] and women 1.485 [95% CI 1.230-1.794] in the validation group) and the largest area under the receiver operating characteristic curve (men 0.598 ± 0.021 and women 0.602 ± 0.021 in the training group). Multivariable Cox regression further indicated that a higher MAP level was independently associated with the future occurrence of MetS. Participants with MAP above the cutoff value (84.0mm Hg for men, 83.3mm Hg for women) had a higher cumulative incidence of MetS than did their counterparts after four years' follow-up in both the training and validation groups. The results derived from the training data could be replicated in the validation data, indicating that the results were generalizable across distinct samples.

Conclusions: MAP is more accurate than SBP, DBP, and PP in predicting future MetS among the normotensive geriatric population. Calculation of MAP is recommended when dealing with normotensive patients aged ≥ 60 years in clinical practice.