Cardiorespiratory fitness and cardiovascular disease risk factors in postmenopausal women. Med. Sci. Sports Exerc., Vol. 30, No. 6, pp. 893-898, 1998.
Purpose: The purpose of the present study was to determine if individuals with high levels of cardiorespiratory fitness have better levels of the cardiovascular disease (CVD) risk factors of total cholesterol (TC), HDL cholesterol (HDL), total cholesterol/HDL cholesterol ratio (TC/HDL), triglycerides (TG), and fibrinogen (FIB) when compared with those with low fitness, in 283 nonsmoking, postmenopausal women. Second, we examined the relation between fitness and CVD risk after controlling for use of hormones and other possible confounding factors.
Methods: These analyses were done on a subset of nonsmoking, postmenopausal women in the Aerobics Center Longitudinal Study (ACLS). Records of postmenopausal women who completed a preventive medicine physical examination between 1987 and 1995 were examined. Cardiorespiratory fitness level was determined by total treadmill time to exhaustion on a graded exercise test; CVD risk factors were assessed via blood analysis.
Results: On cross-sectional regression analysis, fitness was significantly associated (P ≤ 0.005) with TC (r2 = 0.08), TC/HDL (r2 = 0.12), TG (r2 = 0.09), and FIB (r2 = 0.06), and an increase in HDL (r2 = 0.04). After controlling for hormone status, age, year of testing, and blood glucose, each outcome variable remained significantly associated with cardiorespiratory fitness (P < 0.05). TC/HDL and TG continued to be significantly related to cardiorespiratory fitness after adjusting for body mass index (BMI) as a control variable (P < 0.01). The lack of significance between TC, HDL, and FIB with cardiorespiratory fitness after adjusting for BMI is likely due to the biological relationship between cardiorespiratory fitness and BMI (r2 = 0.19).
Conclusions: We conclude that cardiorespiratory fitness is an important independent determinant of blood lipid and FIB levels in nonsmoking postmenopausal women, with or without HRT.
Loma Linda University, Loma Linda, CA 92350; The Cooper Institute for Aerobics Research, Dallas, TX 75230
Submitted for publication August 1997.
Accepted for publication December 1997.
The authors thank the physicians and patients of the Cooper Clinic for their participation in this study, Dr. Kenneth H. Cooper for initiating this study, and Carolyn E. Barlow for data management. Ongoing funding of the ACLS data base is provided by Grant NIH AG06945.
Address for correspondence: Bryan L. Haddock, Loma Linda University, Nichol Hall 1511, Loma Linda, CA 92350. E-mail: bHaddock@ccmail.llu.edu.