Physical inactivity measured by activity quotient score is associated with low cardiac volumes and mass and clinical events in middle-aged subjects from the general population
B T Risberg, A Vittersto, J Nauman, T Berge, A H Ottesen, K Steine, T Omland, A Tveit, M N Lyngbakken, H RosjoAbstract
Background
Physical inactivity is associated with adverse cardiac remodelling and increased risk of major adverse cardiovascular events (MACE). Left atrial and ventricular structure and function are established predictors of cardiovascular morbidity and mortality. The Activity quotient (AQ) is a heart rate-based weekly score that quantifies the health impact of endurance-type physical activity, providing an objective measure of habitual activity, with low scores reflecting physical inactivity. We aimed to investigate whether lower AQ score are associated with unfavourable left atrial and ventricular structure and function, and with higher incidence of MACE in middle-aged adults from the general population.
Methods
We included 3610 participants from the general population, all born in 1950, and examined between 2012 and 2015. Weekly AQ scores were calculated from self-reported physical activity and categorized into four categories: AQ = 0, AQ ≤50, AQ 51–99, and AQ ≥100. Participants with AQ = 0 were classified as physically inactive and served as the reference group. Follow-up continued until 31 December 2022 (median 8.3 years), and MACE was defined as first occurrence of non-fatal myocardial infarction, non-fatal ischemic stroke, non-fatal heart failure, myocardial revascularization (coronary artery bypass grafting or percutaneous revascularization), or cardiovascular death. We used multivariable linear regression models to examine associations between AQ and echocardiographic measures of cardiac structure and function, and Cox proportional hazard models to assess associations between AQ categories and incident MACE. All models were adjusted for age, sex, site, current smoking, cardiovascular disease, hypertension, diabetes, C-reactive protein and atrial fibrillation. Association between physical activity and MACE was presented by Kaplan-Meier plot and we used log-rank test to assess differences between the groups.
Results
Participants had a mean age of 63.9 years (range 62.1–65.7) and 51.2% were male. Inactive participants had significantly smaller left atrial and left ventricular volumes and lower left ventricular mass compared to active participants (Table). Lower AQ scores were significantly associated with higher incidence of MACE during follow-up (log-rank p = 0.001), and physical inactivity (AQ = 0) remained independently associated with MACE after multivariable adjustment (hazard ratio 1.38, CI 1.03-1.84), p=0.03.
Conclusion
In this cohort of middle-aged adults from the general population, physical inactivity as reflected by AQ score of 0, was associated with smaller left atrial and ventricular volumes and lower left ventricular mass compared with higher AQ levels. Inactive individuals also experienced more MACE during follow-up, and this association remained significant after adjustment for established cardiovascular risk factors, highlighting the importance of regular physical activity in midlife.Kaplan Meier Survival CurveTable