Objective: The purpose of this study was to examine independent and joint associations of cardiorespiratory fitness (CRF) and different adiposity measures with mortality risk in individuals with prediabetes (or impaired fasting glucose).
Research design and methods: We examined associations of CRF and fatness with cardiovascular disease (CVD) and all-cause mortality in a cohort of 17,044 participants (89% men) with prediabetes (defined as 100 mg/dL ≤ fasting plasma glucose < 126 mg/dL), who did not have a history of diabetes, CVD, or cancer.
Results: We identified 832 deaths (246 from CVD) during 13.9 ± 7.0 years (mean ± SD) follow-up. Normal-weight individuals who were unfit (lowest one-third) had a higher risk of all-cause (hazard ratio 1.70 [95% CI 1.32-2.18]) and CVD (1.88 [1.13-3.10]) mortality compared with the normal-weight and fit (upper two-thirds) reference group in a model adjusted for age, sex, examination year, and multiple risk factors. The mortality risk for fit individuals who were overweight or obese did not differ significantly from the reference group. Similar patterns were observed for sex-specific thirds of waist circumference and % body fat.
Conclusions: CRF markedly modifies the relationship between adiposity and mortality in persons with prediabetes. Unfit individuals have a higher and fit individuals have a lower mortality risk irrespective of adiposity level in this high-risk group.