Cardio-respiratory fitness is independently associated with cardio-metabolic risk markers in severely obese women

INTRODUCTION: Many studies have shown an inverse relationship between cardio-respiratory fitness and cardio-metabolic risk markers in normal-weight to moderately obese subjects. However, whether such a relationship exists in severely obese subjects is not known.

MATERIALS AND METHODS: Cardio-respiratory fitness was measured by bicycle spiroergometry in 308 severely obese women (all BMI>35 kg/m(2)). The following cardio-metabolic risk markers were assessed: Glycolized hemoglobin levels (HbA1c), fasting glucose, insulin, calculated HOMA index, triglycerides (TG), total, low-, high-density cholesterol (Chol, LDL; HDL), Chol/HDL-Ratio, and uric acid. Computed multiple stepwise linear regression models generally included age, weight and height as independent variables.

RESULTS: Multiple stepwise linear regression models indicated that peak but not aerobic threshold related cardio-respiratory fitness indices were independently of age, weight and height associated with several cardio-metabolic risk markers. Specifically, maximally achieved load (Watt-peak) explained 1.4% of the variance in glucose levels (beta= -0.13; p=0.04) and 2.8% of the variance in HbA1c levels (beta= -0.18; p=0.01), while maximally achieved O2-uptake explained 3.9% of the variance in TG levels (beta= -0.20, p=0.001).

CONCLUSION: Our data for the first time indicate that cardio-respiratory fitness is independently associated with cardio-metabolic risk markers in severely obese women.