Low, No Levels of Exercise Can Increase Mortality Risk More Than Smoking, Diabetes

Physical activity may help improve life expectancy, according to a study from JAMA Network Open, which found that not exercising or getting very little exercise heightens the risk of mortality as much as, or more than, traditional risk factors, including high blood pressure and heart disease.

The study of more than 120,000 patients undergoing exercise treadmill testing at a tertiary care academic medical center contradicts recent observational studies that have indicated an association between regular vigorous exercise and adverse cardiovascular outcomes. In fact, the present study found that extremely high aerobic fitness is associated with the greatest survival benefit, especially among those aged 70 and older and with hypertension.

“Even after adjustment for baseline clinical characteristics, the magnitude of benefit of increased aerobic fitness remains particularly striking,” wrote the researchers. “When compared with the lowest performers, elite performance was associated with an 80% reduction in mortality risk.”

Between January 1, 1991 and December 31, 2014, the researchers enrolled 122,007 patients in the study, and performed a median follow-up of 8.4 years. Patients were stratified by age and performance groups: low (<25th percentile), below average (25th-49th percentile), above average (50th-74th percentile), high (75th-97.6th percentile), and elite (>97.7th percentile).

During the follow-up period and 1.1 million person-years of observation, there were 13,637 deaths from any cause. Elite performers had increased survival compared with all other groups, including high performers.

Not only did the researchers observe an inverse association between increased performance status and long-term mortality, they also found that reduced performance was comparable to, if not significantly greater than, other clinical risk factors, including coronary artery disease (adjusted hazard ratio [HR], 1.29; 95% CI, 1.24-1.35; P<.001), smoking (adjusted HR, 1.41; 95% CI, 1.36-1-1.46; P<.001), and diabetes (adjusted HR, 1.29; 95% CI, 1.34-1.46; P<.001).

Increasing performance was associated with a significant decrease of comorbidities, with the exception of hyperlipidemia, which was present in 31.6% of elite performers and only 25.1% of low performers.

“Importantly, there was no upper limit of benefit of increased aerobic exercise,” noted the researchers. They added, “These findings emphasize the importance of aerobic fitness in overall health, including the magnitude of benefit of increased cardiorespiratory fitness in relation to traditional clinical risk factors and the incremental survival advantage of extremely high fitness.”

For those aged 70 or older, there was a significant reduction in mortality between elite and high performers (adjusted HR, 0.71; 95% CI, 0.52-0.98; P<.001). Similar findings were seen in those with hypertension.

Based on the findings, the researchers advise that healthcare professionals encourage patients to achieve and maintain high levels of fitness.

However, while it is recommended that people get at least 150 minutes of moderate-intensity or 75 minutes of vigorous-intensity physical activity per week, there has been little progress in improving levels of physical activity worldwide, with more than one-fourth of the world’s adult population insufficiently active in 2016.

Reference:

Mandsager K, Harb S, Cremer P, et al. Association of cardiorespiratory fitness with long-term mortality among adults undergoing exercise treadmill testing [published online October 19, 2018]. JAMA Netw Open. doi:10.1001/jamanetworkopen.2018.3605.