Physical activity is reduced in UK Biobank participants that develop postural hypotension

Introduction

Up to 30% of adults over 65 experience postural hypotension (PH) – a significant drop in blood pressure (BP) upon standing. PH is associated with increased risk of falls, frailty, and mortality. Using derived accelerometer data and linked healthcare records, we assessed the relationship between PH and physical activity (PA) in UK Biobank participants.

Methods

We used UK Biobank derived accelerometery data detailing the average time participants spent sleeping (SlA), sedentary (SeA), doing light activity (LA), or moderate & vigorous activity (MVPA). We ascertained participants with a PH diagnosis prior to the accelerometer wear period, those with a diagnosis after this period. We assessed the associations between PH and PA using generalised linear models, compared to controls without PH or recorded hypotension at any timepoint.

Results

96623 participants had sufficient accelerometer data quality. Compared to controls, those with prevalent PH, SlA was 16 minutes lower, (p<0.001), LA was 19 minutes lower (p<0.001) and MVPA 7 minutes lower (p<0.001). SeA was not significantly different. In comparison, those who went on to develop PH had 7 more minutes sleeping (p = 0.012), 22 more sedentary minutes (p<0.001), 24 fewer minutes of LA (p<0.001) and 6 minutes fewer of MVPA (p<0.001) than controls. The mean length of sedentary bouts were 30 seconds longer in those who developed PH (p=0.01) and 55 seconds longer in those with prevalent PH, while active bouts were 26 seconds shorter (p<0.001) and 18 seconds shorter respectively (p<0.001).

Conclusions

These results suggest that changes in physical activity often precipitate clinical diagnoses of PH which highlights the importance of exercise and how changes can be clinically relevant. Further research is needed to understand whether reduced activity is a cause of PH, or a symptom of its development.