Physical Activity Correlates with Reduced Mortality Even in Patients with Multimorbidity
Older patients exhibiting multimorbidity, meaning the presence of two or more diagnosed age-related conditions, are typically in relatively poor shape. Researchers here note that, in this population specifically, greater levels of exercise still correlate with reduced mortality over time. While human data can only show correlation and not causation, extensive animal studies of physical activity give us good reason to think that exercise does in fact act to improve health and that this isn't just a case of less healthy individuals being less able to exercise.
Our study represents one of the pioneering multinational efforts to investigate the longitudinal relationship between physical activity (PA) levels and mortality in individuals with multimorbidity. We found that higher levels of physical activity could significantly reduce mortality risk over an average 12-year follow-up period, even among those dealing with multiple chronic conditions. Our results show that, after adjusting for several potential confounding factors, individuals with multimorbidity who reported moderately low, moderately high and high levels of PA had a 36%, 47%, and 51% reduced mortality risk, respectively, compared to those with low levels of PA.
PA may reduce mortality through several mechanisms. First, engaging in regular PA boosts mitochondrial function, enhancing energy production and decreasing oxidative stress, thereby protecting cells from damage. PA also increases the expression of antioxidant enzymes, which help neutralize harmful free radicals. Second, PA regulates inflammation by lowering pro-inflammatory cytokine levels and raising anti-inflammatory interleukins. It also stimulates autophagy, the process by which cells remove damaged proteins and organelles, ensuring cellular health. Thirdly, PA enhances insulin sensitivity, aiding in blood glucose regulation and potentially slowing the accumulation of molecular damage. Together, these hormonal and molecular changes reduce the risk of chronic diseases and decrease overall mortality.