Visit-to-visit blood pressure variability and future functional decline in old age

OBJECTIVE: Higher blood pressure variability (BPV), independent of mean blood pressure (BP), has been associated with adverse health outcomes. We investigated the association between visit-to-visit BPV and functional decline in older adults at high cardiovascular risk.METHODS: In PROspective Study of Pravastatin in the Elderly at Risk, 4745 participants with mean age of 75.2 years and high cardiovascular risk were followed for a mean of 3.2 years. BP was measured in every 3 months during the first 18 months. BPV was defined as the intraindividual SD of measurements across these visits. Functional status in basic and instrumental activities of daily living was measured using the Barthel (ADL) and Lawton (IADL) scales, first at 18 months and then during follow-up until 48 months. Functional decline was calculated over this period.RESULTS: BPV was not cross-sectionally associated with functional status at 18 months. Higher SBPV was associated with steeper functional decline, whereas DBPV was not. Each 10 mmHg higher SBPV was associated with a 0.064 (95% confidence interval 0.016-0.112, P = 0.009) annual decline in ADL score and with a 0.078 decline (95% confidence interval 0.020-0.136, P = 0.008) in IADL score. These associations were not modified by sex, hypertension or antihypertensives. These findings were independent of mean BP, cardiovascular risk factors and morbidities and cognition.CONCLUSION: Higher visit-to-visit SBPV but not DBPV was associated with steeper functional decline in older adults at high cardiovascular risk. Higher SBPV is a novel risk factor for functional decline.