Greater cardiorespiratory fitness could reduce risk for dementia by 40%

Key takeaways:

• The onset of all dementia was delayed by 1.48 years in people with high cardiorespiratory fitness (CRF).
• CRF could serve as a routine health monitoring tool or an indicator of health conditions.

High cardiorespiratory fitness corresponded with better cognitive function and a decreased risk for dementia, according to findings published in the British Journal of Sports Medicine.

This risk reduction was seen even in those with a high genetic likelihood for Alzheimer’s disease, the researchers wrote.

Cardiorespiratory fitness (CRF) declines as people age, decreasing from 3% to 6% per decade when aged 20 to 39 years and by 20% per decade when aged 70 years and older, according to Shuqi Wang, from Tianjin Medical University in China, and colleagues.

Most recent studies assessing the relationship between CRF and dementia “have been characterized by relatively small sample sizes, limited populations and inconsistent finding,” the researchers wrote.

In the current analysis, Wang and colleagues examined a cohort of 61,214 participants aged 39 to 70 years and free of dementia from the UK Biobank, who were followed up for up to 12 years.

Researchers used result from a 6-minute submaximal exercise test on a stationary bike at baseline to estimate CRF levels — categorized as low, medium or high — among participants while measuring cognitive function through neuropsychological tests.

The researchers also determined genetic predisposition for dementia through the polygenic risk score for Alzheimer’s disease.

During the follow-up period, 553 people developed dementia.

High CRF corresponded with better global cognitive function vs. low CRF (beta = 0.05; 95% CI, 0.04-0.07).

Wang and colleagues found that the risks for all dementia and Alzheimer’s disease decreased by 40% (incidence rate ratio [IRR] = 0.6; 95% CI, 0.48-0.76) and 38% (IRR = 0.62; 95% CI, 0.43-0.89), respectively, for people with high CRF compared with those with low CRF.

Meanwhile, the onset of all dementia among those with high CRF was delayed by 1.48 years (95% CI, 0.58-2.39) vs. those with low CRF.

In people with a moderate to high polygenic risk score, high CRF reduced the risk for all dementia by 35% (IRR = 0.65; 95% CI, 0.52-0.83).

The researchers highlighted some possible mechanisms behind the findings.

“CRF represents the function of the cardiovascular system, respiratory system, and skeletal muscle metabolism, and is an objective reflection of the overall health status,” they wrote. “Previous studies have related cardiovascular disease, low pulmonary function, and sarcopenia to dementia risk. Therefore, CRF could serve as an indicator of dementia risk.”

There were also a couple of limitations. Wang and colleagues noted that UK Biobank participants are typically healthier and more socioeconomically advantaged compared with the general population, whereas some participants with health conditions were excluded from the analysis, potentially leading to a lower incidence of dementia and an underestimation of the associations.

Still, “as the measurement of CRF in clinical settings becomes both important and feasible, CRF may be used as a routine health monitoring tool or an indicator of health conditions,” they concluded.

References:

• High cardiorespiratory fitness linked to lower risk of dementia. Available at: https://www.eurekalert.org/news-releases/1065056. Published Nov. 19, 2024. Accessed Nov. 19, 2024.
• Wang S, et al. Br J Sports Med. 2024;doi:10.1136/bjsports-2023-108048.