High cardiorespiratory fitness (CRF) in generally healthy men was associated with a reduced risk for cardiovascular disease (CVD) irrespective of age and coronary artery calcium (CAC) levels, according to findings published in Circulation.
A total of 8425 men free of CVD who received preventive health care from a single center between 1998 and 2007 were included in the analysis. Preventive health care consisted of anthropometric measurements, fasting laboratory studies, a standardized medical examination, and an objective measurement of CAC and CRF using electron beam computed tomography scanning and a maximal treadmill exercise test, respectively.
During the mean follow-up of 8.4 years, 383 CVD events were observed. Increasing CAC correlated with increasing CVD events, whereas increasing CRF tended to correlate with decreasing CVD events. Only 1.3 CVD incidence rates per 1000 person years were observed in patients with no CAC vs 18.9 CVD events per 1000 person years in patients with CAC ≥400 (P <.001).
In addition, significantly higher hard CVD events (CVD death, nonfatal myocardial infarction, nonfatal atherosclerotic stroke) occurred in patients with CAC ≥400 vs no CAC (5.9 per 1000 person years vs 0.9 per 1000 person years, respectively; P <.001). Each additional metabolic equivalent of fitness correlated with an 11% lower total CVD event risk (hazard ratio, 0.89; 95% CI, 0.84-0.94; P <.001). Investigators assessed CRF and CAC together and found that across all the CAC groups a consistent association existed between continuous CRF and CVD incidence rates.
This study has limited generalizability as it included only men, most of whom were white and well-educated. In addition, the study may have been underpowered to assess for hard coronary heart disease and stroke events as only 383 total CVD events occurred during follow-up.
Using preventive measures “that reduce the risk [for] adverse CVD outcomes at any given level of CAC burden could have a substantial impact on improving public health” as well as minimize future healthcare cost burdens associated with CVD treatment.
Radford NB, DeFina LF, Leonard D, et al. Cardiorespiratory fitness, coronary artery calcium and cardiovascular disease events in a cohort of generally healthy, middle aged men: results from the Cooper Center Longitudinal Study [published online January 17, 2018]. Circulation. doi:10.1161/CIRCULATIONAHA.117.032708