Cardiorespiratory capacity is associated with favourable cardiovascular risk profile in patients with Type 2 diabetes

The aim of this study was to examine the interaction between cardiorespiratory capacity and cardiovascular risk factors in patients with Type 2 diabetes mellitus (T2DM).

A total of 92 patients with T2DM (40 men, 52 women) performed a symptom-limited exercise test on ergocycle, with continuous gas exchange measurement. All patients were overweight or obese (body mass index >25 kg/m(2)), with poor glycemic control (hemoglobin A(1c) >7%), but free from overt diabetic vascular complications. Anthropometric parameters, blood pressure (BP), cardiorespiratory fitness, glycemic and lipid profile, fibrinogen, plasminogen activator inhibitor-1, high-sensitivity C-reactive protein (hsCRP), insulin resistance, and 24-h urinary albumin excretion (UAE) were measured. Based on the median Vo(2) peak value, participants were placed into low fitness (LF, n=46) or moderate fitness group (MF, n=46).

In univariate analysis, exercise capacity correlated with systolic (r=-0.349) and diastolic BP (r=-0.441), waist circumference (r=-0.345), total cholesterol (r=-0.348), high-density lipoprotein (HDL) (r=0.362), UAE (r=-0.486), homeostasis model assessment (HOMA-IR) (r=-0.467), uric acid (r=-0.316), and hsCRP (r=-0.217, only in women subgroup) (P<.05). With the exception of the latter three variables, the above associations remained significant after controlling for age and sex in multiple regression analysis (P<.05). Compared to LF group, patients in MF group showed significantly higher levels of HDL and lower levels of BP, waist circumference, hsCRP, and HOMA-IR (P<.05). In addition to this, UAE tended to be lower in fit patients (P=.054).

Low cardiorespiratory fitness seems to be independently associated with most traditional and emerging cardiovascular risk factors in patients with T2DM. Even a moderate increase of cardiorespiratory fitness exerts beneficial effects on cardiovascular risk profile.