Introduction: There are no published data regarding the joint association of cardiorespiratory fitness (CRF) and LDL cholesterol concentration with subsequent CHD mortality in men.
Methods: A total of 40,718 healthy men received a comprehensive baseline clinical examination between 1971 and 2006. CRF was determined from a maximal treadmill exercise test. Participants were divided into categories of low (quintile 1), moderate (quintiles 2–3), and high (quintiles 4–5) CRF by age group, as well as by Adult Treatment Panel III–defined LDL categories. HRs for CHD mortality were computed with Cox regression analysis.
Results: A total of 557 deaths due to CHD occurred during 16.7 ± 9.0 yr (681,731 man-years) of follow-up. After adjustment for age, examination year, smoking status, family history, and body mass index, a significant positive trend in CHD mortality was shown across decreasing categories of CRF. HRs with 95% confidence interval were 1.0 (referent), 1.18 (0.94–1.47), and 2.10 (1.65–2.67) for high, moderate, and low fit groups, P trend <0.0001. Adjusted HRs were significantly higher across increasing LDL categories: 1.0 (referent), 1.30 (0.87–1.95), 1.54 (1.04–2.28), 2.16 (1.45–3.21), and 2.02 (1.31–3.13), P trend <0.0001. When grouped by CRF category as well as by LDL category, there was a significant positive trend (P < 0.02) in adjusted mortality across decreasing categories of CRF within each LDL category.
Conclusions: CRF is strongly and inversely associated with CHD mortality in men. Compared with men with low CRF, at a moderate to high level of CRF, the risk of mortality within each LDL category is significantly attenuated. This study suggests that measurement of CRF should be considered for routine cardiovascular risk assessment and risk management.
1The Cooper Institute, Dallas TX; and 2Center for Human Nutrition, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX
Address for correspondence: Stephen W. Farrell, Ph.D., The Cooper Institute, 12330 Preston Road, Dallas, TX 75230; E-mail: firstname.lastname@example.org.
Submitted for publication April 2012.
Accepted for publication June 2012.