Associations between cardiorespiratory fitness and the metabolic syndrome in British men

Background: Age and body mass index (BMI) are positively associated with the develop-ment of the metabolic syndrome (MetS). Cardiorespiratory fitness (CRF) can attenuate BMI-related increases in prevalence of MetS, but the nature of this association across different age strata has not been fully investigated. Aim: To identify the association between CRF and MetS prevalence across age-strata (20– 69 years) and determine whether associations are independent of BMI. Methods: CRF was estimated from incremental treadmill exercise in British men attending preventative health screening. Participants were placed in four age strata (20-39, 40-49, 50-59 and 60-69 years) and classified as Fit or Unfit using age-related cut-offs. Presence of MetS was defined using the National Cholesterol Education Program Adult Treatment Panel III criteria. Results: 9 666 asymptomatic men (48.7±8.4 years) were enrolled. The prevalence of MetS was 25.5% in all men, and ranged from 17.1% in 20-39 year olds to 30.6% in 60-69 year olds. Fit men’s likelihood of meeting the criteria for MetS was half (OR=0.51, 95%CI:0.46-0.57) that of unfit men. The likelihood of MetS was 32-53% lower across age strata in Fit, com-pared with Unfit men. Adjustment for BMI attenuated the association, though it remained significant in men aged 20-49 years. Conclusion: The cardio-metabolic benefits of CRF are independent of BMI particularly in men <50 years. Public health messages should emphasise the important role of CRF along-side weight management for enhancing cardio-metabolic health.

http://dx.doi.org/10.1136/heartjnl-2016-310142