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

Abstract

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 (VO 2max ) by respiratory gas analysis during a maximal bicycle exercise test. RESULTS-VO 2max 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 VO 2max 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 Ͻ 0.001 all) of metabolic syndrome than those with the highest VO 2max after multivariable adjustments. Factor analysis generated a principal factor that was strongly loaded by the main components of metabolic syndrome and VO 2max (Ϫ0.68 in men and Ϫ0.70 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. Diabetes Care 31:1242-1247, 2008T he epidemic of metabolic syndrome is due in part to sedentary lifestyle, poor cardiorespiratory fitness, unhealthy diet, and increased overweight and obesity (1). Metabolic syndrome is associated with an increased risk of type 2 diabetes, cardiovascular disease (CVD), and premature mortality (2,3). Higher levels of physical activity and cardiorespiratory fitness have been associated with a decreased risk of developing metabolic syndrome (4 -7) and its consequences of type 2 diabetes, CVD, and premature mortality (8 -11).Only a few population-based studies have been published on the association of cardiorespiratory fitness with metabolic syndrome (4,5,7,12,13). Most have included only young and middle-aged individuals or men and have used indirect measurements of maximal oxygen uptake (VO 2max ). We have previously found strong association of a low VO 2max with an increased risk of having or developing metabolic syndrome in middle-aged men (4,12). Based on factor analysis, we have suggested that poor cardiorespiratory fitness could be considered a feature of metabolic syndrome (12).We assessed the association of directly measured VO 2max with metabolic syndrome and impaired glucose metabolism in a large population sample of older men and women. Because metabolic syndrome consists of highly correlated features, factor analysis was used as a complementary statistical approach. The present study extends our knowledge on the association of cardiorespiratory fitness with metabolic syndrome in middleaged men (12) to older men and women, the fastest growing segment of the population. RESEARCH DESIGN AND METHODS -We used the baseline data of the Dose-Responses to ExerciseTraining Study (DR's EXTRA), which is an ongoing 4-year randomized controlled trial o...

Food consumption, nutrient intake and the risk of having metabolic syndrome: the DR's EXTRA Study

“…A participant was classified as having MetS if he/she had X3 of the following criteria: waist circumference 4102 cm in men and 488 cm in women; serum triglycerides X1.7 mmol/l; serum high-density lipoprotein cholesterol o1.03 mmol/l in men and o1.29 mmol/l in women; systolic blood pressure X130 mm Hg or diastolic blood pressure X85 mm Hg or use of antihypertensive medication; fasting plasma glucose X6.1 mmol/l. These measurements have been described in detail previously (Hassinen et al, 2008).…”

“…The present cross-sectional data are based on baseline examinations of an ongoing population-based randomised controlled trial, the Dose Responses to Exercise Training (DR's EXTRA) Study, described in detail previously (Hassinen et al, 2008). The target population was a sample of 3000 individuals who were randomly selected from the national population register in 2002.…”

“…Cardiorespiratory fitness was assessed by defining maximal oxygen uptake (VO 2max ) from respiratory gas analysis during a maximal symptom-limited exercise stress test on a bicycle ergometer (Ergoline, Bitz, Germany) as described previously (Hassinen et al, 2008). Physical activity was assessed by the DR's EXTRA Physical Activity Interview, which is modified from the questionnaire of Jackson et al (1990) and has been described in detail previously (Hakola et al, 2010).…”

Association between Muscular Strength and Metabolic Risk in Japanese Women, but Not in Men

“…However, because low fitness and excess body fat often occur in combination, it is important to distinguish the separate effects on metabolic risk factors related to MeS. A few recent studies have examined the relative contribution of abdominal adiposity and CRF to metabolic risk, demonstrating that higher CRF and lower abdominal adiposity are each independently associated with a substantial reduction in metabolic risk related to MeS (Hassinen et al, 2008;Lee et al, 2005). However, few studies have investigated the independent contribution of muscular strength and abdominal fat to individual and clustered metabolic risk factors.…”

“…Both low fitness (cardiorespiratory fitness (CRF) and muscular strength) and increased adiposity have increasingly been recognized as important risk factors associated with MeS in adults (Hassinen et al, 2008;LaMonte et al, 2005;Sayer et al, 2007). However, because low fitness and excess body fat often occur in combination, it is important to distinguish the separate effects on metabolic risk factors related to MeS.…”