Cardiorespiratory fitness is decreased and not correlated with C-Reactive Protein levels in adults with Diabetes Mellitus
C. Francisco, A. Catai, S. Moura, S. Lopes, A. Del Vale & A. Leal
Diabetes Mellitus (DM) has been associated with lung dysfunction and impairment of cardiorespiratory fitness and increasing evidences have suggested that comorbidities and systemic inflammation may be involved in these derangements. However, the results regarding cardiopulmonary dysfunction and its underlying mechanisms in DM are still controversial. In this study, we evaluated the relationship between metabolic variables and inflammation marker, including hemoglobin A1C (HbA1C), lipid profile and C-reactive protein (CRP) levels, and cardiorespiratory fitness in adult patients with DM. Nineteen men with diabetes (aged 51±6 years; mean ± SD) and nineteen age and sex-matched control subjects (aged 49±7 years) were studied. The average duration of diabetes was 11 years (range, 225 years) and the HbA1C mean levels were 8.4% (range, 612.9%). All individuals were subjected to incremental cardiopulmonary exercise test and spirometry. Blood pressure, triglycerides, HDL, LDL, total cholesterol and CRP were not different in control subjects and individuals with DM. Body mass index (28.7±1 vs 25.6±0.4 kg/m2, mean ± SD, P<0.01) and resting heart rate (78.3±2.2 vs 71.3±2.1 beats/min, mean ± SD, P=0.03) were significantly higher in individuals with DM than in control subjects, respectively. No significant difference was noted in spirometric variables, including forced vital capacity (FVC), forced expiratory volume in 1s (FEV1), forced expiratory flow midexpiratory phase (FEV2575%) and peak expiratory flow (PEF). In the exercise test, maximal overload (W), peak heart rate (HRpeak), peak oxygen consumption (VO2peak) at anaerobic threshold (VO2AT) and respiratory exchange ratio (RER) were significantly lower in patients with diabetes than in control subjects. No correlations were observed between HbA1C and CRP plasma levels and cardiorespiratory variables. These data indicate that cardiorespiratory fitness is reduced and spirometric values are preserved in patients with diabetes. However, decreased cardiorespiratory fitness is not correlated with CRP levels or HbA1C.
Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.
Funding: This work was supported, however funding details unavailable.