Genetic Factors Linked to Increased Muscle Strength May Reduce Cardiovascular Mortality Risk

A recent study conducted by researchers at the Faculty of Sport and Health Sciences at the University of Jyväskylä in Finland highlights a significant correlation between genetic predisposition to greater muscle strength and a decreased risk of cardiovascular mortality in men. This association remains influential regardless of the individual's level of physical activity during leisure time or other lifestyle factors.

The findings, published in the Journal of the American Heart Association, underscore the health risks associated with low muscle strength, particularly handgrip strength, which has been linked to a heightened risk of premature death. While physical activity can mitigate muscle strength decline, higher muscle strength may encourage individuals to engage more actively in physical pursuits. The study aimed to discern whether genetic predisposition to enhanced muscle strength correlates with lower mortality rates, particularly in relation to cardiovascular health, while also exploring the impact of leisure-time physical activity.

The results indicated that men with a genetic inclination towards higher muscle strength exhibited a modest reduction in cardiovascular mortality risk. Importantly, this correlation persisted even after controlling for various lifestyle factors such as smoking habits, alcohol consumption, and body mass index. Contrary to previous assumptions, the relationship between inherited muscle strength and mortality risk was not contingent upon the level of physical activity.

Researcher Päivi Herranen emphasized that the connection between genetic muscle strength and reduced mortality risk was consistent, irrespective of an individual's activity level. Interestingly, the study also revealed that a genetic predisposition to greater muscle strength does not inherently increase a person's overall physical activity levels.

In contrast, the study did not find a similar association between inherited muscle strength and mortality risk in women. This discrepancy may be attributed to biological and environmental factors that differently influence cardiovascular health across genders. Herranen noted that genetic and physiological traits that boost muscle strength in women could concurrently heighten their vulnerability to cardiovascular diseases, especially as age increases. Further research involving larger sample sizes is necessary to examine this potential connection more closely.

The research utilized a polygenic score that aggregated the effects of numerous genetic variants linked to handgrip strength. This scoring system allows for comparative analysis between individuals with significantly high or low genetic predispositions, thereby providing valuable insights into the relationship between muscle strength and health risks.

Although the polygenic score for muscle strength has limited predictive capacity on its own, it offers comparable predictive power to several lifestyle factors. Future investigations will be necessary to determine how this score can be integrated into personalized health risk assessments.

Moreover, the polygenic score may assist in understanding how genetic predisposition influences an individual's response to exercise and their potential for improvement through training. The study analyzed genetic and lifestyle data from approximately 9,000 participants in the older Finnish Twin Cohort. Comprehensive information regarding participants' education, body mass index, smoking habits, alcohol use, and physical activity was collected via questionnaires administered at three different intervals.

This research was recognized with the second prize in the Best Research Paper in Sports Medicine Competition at the Helsinki Sports Medicine Days in 2024 and represents the third publication in Herranen's doctoral dissertation, which explores the interplay between genetics and environmental factors in biological aging, focusing on the decline of muscle strength and functional capacity with age.