Cardiorespiratory capacity is associated with favourable cardiovascular risk profile in patients with Type 2 diabetes☆
Received 7 August 2007; received in revised form 14 December 2007; accepted 27 December 2007. published online 14 March 2008.
Abstract
Objective
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).
Research Design/Methods
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/m2), with poor glycemic control (hemoglobin A1c >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 V̇o2 peak value, participants were placed into low fitness (LF, n=46) or moderate fitness group (MF, n=46).
Results
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).
Conclusions
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.