Vigorous physical activity may prevent disabling dementia in men: JAMA

Japan: In a new study conducted by Hikaru Ihira and the team, it was found that a high level of moderate to vigorous physical activity (MVPA) during leisure time is related to a lower risk of debilitating dementia in males. The findings of this study were published in the Journal of American Medical Association.

The relationships between daily total physical activity and total moderate to vigorous physical exercise and dementia remain unknown. As a result, this study was designed to look at the relationship between daily total physical activity and the risk of developing disabling dementia in an extended large-scale follow-up prospective study.

This prospective cohort research used data from the Japan Public Health Center-based Prospective Disabling Dementia Study questionnaires gathered between 2000 and 2003 from 8 locations. Adults aged 50 to 79 years old with available follow-up data on debilitating dementia were eligible to participate. The data was analyzed between February 1, 2019, and July 31, 2021. Daily total physical activity, total MVPA, and leisure-time MVPA were all requested of participants. The key result was the incidence of debilitating dementia between 2006 and 2016, as determined by the national long-term care insurance system. The risks of dementia were determined using multivariable-adjusted hazard ratios in relation to total MVPA, daily total physical activity, and leisure time MVPA.

The findings of this study were as follows:

1. During the dementia ascertainment period, 5010 patients were newly diagnosed with debilitating dementia over a mean (SD) of 9.5 years.

2. Men had a decreased risk of dementia in the greatest daily total physical activity group compared to the lowest activity group.

3. Men and women both had inverse relationships with overall MVPA and leisure-time MVPA.

4. These inverse relationships vanished when people diagnosed with debilitating dementia within 7 years of the beginning point in males and within 8 years in women were omitted.

5. After eliminating people diagnosed within the first 9 years, the link remained significant among males in the highest vs lowest category of leisure-time MVPA.

In conclusion, a possible reverse causation bias in the relationship between daily total physical activity and total MVPA with the risk of disabling dementia in men and women was discovered in this large prospective cohort research. Leisure-time MVPA, on the other hand, may have a protective effect against debilitating dementia in males.

Reference:

Ihira H, Sawada N, Inoue M, et al. Association Between Physical Activity and Risk of Disabling Dementia in Japan. JAMA Netw Open. 2022;5(3):e224590. doi:10.1001/jamanetworkopen.2022.4590

Keywords: Physical activity, exercise, disabling dementia, physiotherapy, memory, leisure-time, workout, cognition, neuroprotection, JAMA