Higher daily step counts tied to lower risk of dementia: JAMA

UK: Higher-intensity exercise and accumulating more steps each day may be linked to a lower risk of dementia onset, just beneath the widely accepted threshold of 10,000 steps per day, states a study published in JAMA Neurology.

A common method of giving the general public physical activity goals is through step counts. It has been claimed that an ideal dose of 6000–8000 steps can lower the risk of mortality from all causes. Guidelines for dementia prevention may be best served by step-based advice. Nevertheless, it is unclear whether step count and intensity correlate with the prevalence of dementia.

The authors aimed to investigate the dose-response relationship between regular step count and the severity and frequency of dementia from all causes among individuals in UK.

For this purpose, during the period of February 2013 to December 2015, a UK Biobank prospective population-based cohort research was carried out and data analysis was completed in May 2022. All 103 684 eligible adults between the ages of 40 and 79 who had accurate wrist accelerometer data were included, making up 78 430 people in all. Through October 2021, registry-based dementia was determined. They employed cadence-based stepping metrics that captured pace and intensity in unrestricted circumstances, including incidental steps (measured as fewer than 40 steps per minute) and purposeful steps (described as 40 or more steps per minute) during exercise, as well as peak 30-minute cadence. The primary outcomes included incident dementia (fatal and nonfatal), which was discovered through linking with inpatient hospitalization or primary care records, or listed as the primary or contributing cause of death in death registers. To evaluate dose-response relationships, Spline Cox regressions were employed.

Key results of the study:

• Dementia affected 866 out of 78 430 adults (mean age, 68.3 years of which 55.4% were men and 54.6% were women. Also among them were 0.6% Asians, 0.7% Blacks, 0.4% mixed race, 97.6% White, and 0.7% other.
• The risk reduction was detected at the optimal dose, or exposure value, of 9826 steps (hazard ratio [HR], 0.49), and at the lowest dose, or exposure value, of 3826 steps (HR, 0.75), which was 50% of the observed maximum risk reduction.
• The optimal 30-minute cadence was 112 steps per minute (HR, 0.38), with the incidental cadence optimal dose being 3677 steps (HR, 0.58; 95% CI, 0.44-0.72), the purposeful cadence optimal dose being 6315 steps (HR, 0.43).

"By avoiding the least active end of the step-count distributions, dementia prevention for the entire population may be enhanced. Our findings emphasize the significance of stepping intensity for preventing dementia, in contrast to earlier studies looking at mortality outcomes", the researchers wrote.

The authors concluded that the incidence of incident all-cause dementia was shown to be reduced in people who walked more frequently each day. The ideal dose was determined to be 9800 steps per day, which is just short of the usual goal of 10,000 steps. Stronger associations were produced by more vigorous walking.

REFERENCE

del Pozo Cruz B, Ahmadi M, Naismith SL, Stamatakis E. Association of Daily Step Count and Intensity With Incident Dementia in 78 430 Adults Living in the UK. JAMA Neurol. Published online September 06, 2022. doi:10.1001/jamaneurol.2022.2672