The Cross-sectional And Longitudinal Associations Of Adiposity Measures And Cardiorespiratory Fitness Among Adult Men And Women.

Alongside engaging in physical activity, previous Cooper Center Longitudinal Study (CCLS) research found that unhealthy weight status augments age-related declines in cardiorespiratory fitness (CRF). While body mass index (BMI) has been used as a measure of weight status, it has limitations; therefore, other measures of adiposity should be examined as determinants of CRF. PURPOSE: To examine the cross-sectional and longitudinal associations between adiposity measures (body fat percentage, waist circumference, BMI) and CRF over time among adults. METHODS: A total of 2,706 apparently healthy men and women aged ~47 years (on average) who presented at the Cooper Clinic (Dallas, TX) for preventive health at least 4 times participated in this study. The associations between the adiposity variables and CRF were estimated using mixed effects linear regression while adjusting for covariates. RESULTS: Multivariable analysis revealed that cross-sectionally a 1 kg/m2 higher BMI was related to a 0.28 MET (95%CI 0.26, 0.30; p < 0.001) lower CRF in a between-person comparison. Longitudinally, a 1 kg/m2 increase in BMI was associated with a 0.33 MET (95% CI 0.31, 0.34; p < 0.001) decrease in CRF during follow-up (median 9.1 years). In addition, 1 cm higher waist circumference was associated with a 0.10 MET (95%CI 0.09, 0.11; p < 0.001) lower CRF between individuals. Longitudinally, a 1 cm increase in waist circumference was related to a 0.07 (95%CI 0.06, 0.07; p < 0.001) decrease in METs within individuals during follow-up. With regard to body fat percentage, a 1 percentage point increase in body fat percentage was associated with a 0.21 (95%CI 0.20, 0.22; p < 0.001) lower MET level cross-sectionally. Similarly, a 1 percentage point increase in body fat percentage was associated with a 0.12 (95%CI 0.12, 0.13; p < 0.001) MET decrease in CRF longitudinally. When examining the variance explained in longitudinal models by adiposity measures, body fat percentage explained 21.8% of the within-person variance, followed by waist circumference (16.9%), and BMI (15.5%) compared to a model without body fat percentage, waist circumference, or BMI. CONCLUSION: Increases in adiposity measures were all related to decreases in CRF at baseline and over time. Additionally, body fat percentage appears as a strong explanatory measure of CRF.