Association between Cardiorespiratory Fitness and Glycemic Control in Individuals with Type 2 Diabetes Mellitus

The aim of this study was to investigate the independent associations of cardiorespiratory fitness (CRF) with glycemic control parameters in individuals with type 2 diabetes mellitus (T2DM). A total of 44 individuals with T2DM (age: 52.20 ± 9.02 years; T2DM duration: 5.39 ± 4.65 years; baseline glycated hemoglobin (HbA1C): 7.05 ± 0.78%) participated in this study. Following blood analysis, anthropometric assessments, and resting blood pressure measurements, participants performed the Six-Minute Walk Test (6MWT) to estimate peak oxygen uptake (VO₂peak). The main findings indicated that relative VO₂peak was significantly and inversely associated with HbA1C in the unadjusted model (B = -0.12, p = 0.03), explaining 10.7% of the variance. However, this association was attenuated and became non-significant after adjusting for age, T2DM duration, and body mass index (BMI). Neither relative nor absolute VO₂peak was significantly associated with fasting blood glucose (B = -0.41, p = 0.42 and B = -0.13, p = 0.20, respectively). Age emerged as the only independent predictor of FBG (B = 0.07, p = 0.04). These results suggest that the association between CRF and long-term glucose regulation in this population is complex and heavily influenced by demographic and anthropometric factors, highlighting the need for a multifactorial approach in clinical assessments.