It is well known that physical activity (PA) is one of the cornerstones of prevention of cardiovascular diseases and all-cause mortality. There is a hypothesis that leisure time PA is associated with reduced adverse cardiovascular events, while occupational PA, on the contrary, may lead to increased risk. On April 9, 2021, the European Heart Journal published the results of the analysis of this hypothesis based on data from a large-scale population study of Copenhagen residents (Copenhagen General Population Study).
In total, the analysis included 104,046 men and women aged 20 to 100 years, whose baseline measurements were in 2003-2014, with median follow-up duration of 10 years. The authors investigated the risk of major adverse cardiovascular events (MACE, defined as fatal and non-fatal myocardial infarction, fatal and non-fatal stroke, or other coronary deaths), as well as overall mortality depending on the level of leisure time and occupational PA. Individuals with pre-existing MACE were excluded from the statisticalanalyses to avoid reverse causality. During 10 years of follow-up, 7913 (7.6%) MACE and 9846 (9.5%) deaths from all causes were observed. Compared to low leisure time PA, multivariable adjusted (for lifestyle, health, living conditions, and socioeconomic factors) hazard ratios for MACE were 0.86 (0.78–0.96) for moderate, 0.77 (0.69–0.86) for high, and 0.85 (0.73–0.98) for very high activity; corresponding values for higher occupational PA were 1.04 (0.95–1.14), 1.15 (1.04–1.28), and 1.35 (1.14–1.59), respectively. The results for all-cause mortality were similar. These effects of leisure time and occupational PA were independent of each other.
Due to the study sample based only on Danish population, these results might not be generalizable to all other countries in Europe and elsewhere. Therefore, it is very important to perform studies on the physical activity paradox in other countries and populations, particularly in low-income and less-privileged ones.
The physical activity paradox is suggested to be explained by the different characteristics of physical activity during work and leisure time, where leisure time physical activity primarily comprises dynamic activities of higher intensity and shorter durations, while occupational physical activity is composed of more static and constrained activities of lower intensity and long durations.
European Heart Journal April 14, 2021
DOI: 10.1093/eurheartj/ehab087
https://academic.oup.com/eurheartj/article/42/15/1499/6213772
