Abstract
Background Even subjects with severe obesity show a wide range of
metabolic health states, with some showing marked alterations in glucose and
lipid metabolism whereas others do not. In severely obese women, we could
recently show that the degree of cardiorespiratory fitness is, independently of
body mass and age, associated with several markers of glucose and lipid
metabolism.
Aims In our retrospective study on a clinical data set, we questioned
whether such an association also exists in severely obese men.
Methods Cardiorespiratory fitness, i. e. workload
(Wpeak) and oxygen uptake (V̇O2,peak) at peak
exercise, was assessed by a bicycle spiroergometry in 133 severely obese men
(all BMI>35 kg m−2). The following metabolic
blood markers were also measured: Fasting serum glucose, insulin, triglycerides
(TG), total, low-, high-density cholesterol (Chol, LDL, HDL), uric acid, and
whole blood glycated hemoglobin (HbA1c). The Chol/HDL ratio and
Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) were also
calculated.
Results Multiple stepwise linear regression models including age, body
mass, and smoking status as independent variables revealed that Wpeak
and V̇O2,peak, explained 4.5 to 10.7% of variance in
HbA1c and TG (all beta<− 0.22; all p<0.02).
Including fat free mass instead of body mass in respective models revealed that
both Wpeak and V̇O2,peak were predictors of HbA1c
and TG (all beta<− 0.265; all p<0.013),
respectively, while Wpeak also accounted for variance in glucose and
Chol (both beta<− 0.259; both p<0.023).
Conclusions Similar to previous observations in women, our data indicate
that cardiorespiratory fitness assessed by bicycle ergospirometry test is
associated with glucose and lipid metabolism in severely obese men. The strength
of the found associations suggest a mild to moderate influence of
cardiorespiratory fitness on metabolic health in severe obesity.
Key words
physical fitness - obesity - glucose metabolism - lipids - spiroergometry
