Cardiorespiratory Fitness as a Feature of Metabolic Syndrome in Older Men and Women

OBJECTIVE—We studied the associations of cardiorespiratory fitness with metabolic syndrome in older men and women, because such data are limited in representative population samples. RESEARCH DESIGN AND METHODS—We studied a population sample of 671 men and 676 women aged 57–79 years at baseline of a randomized controlled intervention study. We assessed maximal oxygen uptake (Vo2max) by respiratory gas analysis during a maximal bicycle exercise test. RESULTS—Vo2max had a strong, inverse, and graded association with the risk of having metabolic syndrome as defined by the National Cholesterol Education Program criteria. Men and women in the lowest third of Vo2max had 10.2- and 10.8-fold higher risks and those in the middle third had 2.9- and 4.7-fold higher risks (P < 0.001 all) of metabolic syndrome than those with the highest Vo2max after multivariable adjustments. Factor analysis generated a principal factor that was strongly loaded by the main components of metabolic syndrome and Vo2max (−0.68 in men and −0.70 in women). CONCLUSIONS—Low cardiorespiratory fitness is associated with metabolic syndrome in older men and women. Our findings suggest that low cardiorespiratory fitness could be considered a feature of metabolic syndrome.