Alerting reaction of blood pressure and risk of mortality in an elderly Chinese population.

Hypertension guidelines recommend multiple blood pressure measurements to minimize the potential initial alerting reactions. This study investigated the prognostic significance of this reaction in elderly individuals. The study subjects (aged ≥60 years) were recruited from the suburban Shanghai. Blood pressure was measured three times consecutively with a 60 s interval in the sitting position using an oscillometric device. An alerting reaction was defined as that the first blood pressure reading exceeded the average of the subsequent two readings. In the total of 4512 participants (44.7% men, average age 66.8 years), those with an alerting reaction (n = 2633) were younger than those without (n = 1879; 65.8 vs. 68.0 years, P < 0.0001). During 5.9 years median follow-up (24,576 person-years), 430 and 221 total and cardiovascular deaths occurred, respectively. Adjusted Cox regression analyses showed that individuals with an alerting reaction had an 18% lower risk of total mortality (HR, 0.82; 95% CI, 0.67-0.99; P = 0.04) and 36% lower risk of cardiovascular mortality (HR, 0.64; 95% CI, 0.48-0.89; P = 0.002) than those without alerting reaction. Further categorical analyses on the greater differences showed that the hazard ratio for an alerting reaction of >5 mmHg (n = 1448) versus ≤-5 mmHg (n = 832) was 0.75 (95% CI,0.57-0.99; P = 0.04) and 0.57 (95% CI, 0.38-0.85; P = 0.006) for total and cardiovascular mortality, respectively. In conclusion, this study first identified that the alerting reaction of blood pressure was associated with a notably lower mortality risk in an elderly population. The underlying mechanism should be investigated in future studies.