秋三 熊谷

Contribution of the oxygen uptake at the double product-break point to metabolic syndrome in male patients with newly diagnosed type 2 diabetes mellitus. : Endurance fitness and metabolic syndrome

The maximal oxygen uptake (VO2max), a maximal-endurance fitness (EF) measure is associated with the metabolic syndrome (MS) in patients with impaired glucose tolerance and type 2 diabetes mellitus (type 2 DM). The contribution of submaximal EF to MS is still not known. This report describes the contribution of submaximal EF, which is characterized by the oxygen uptake corresponding to the double product-break point (VO2 at the DPBP) on the prevalence of MS in newly diagnosed type 2 DM. The subjects of this cross-sectional study were 90 Japanese male patients with newly diagnosed type 2 DM (aged 53.0 ± 11.7 years) who had not been under any intervention (pharmaco-, diet-, and exercise therapy). VO2 at the DPBP was measured by ramp exercise test. MS was defined by the NCEP-ATP III criteria modified by Japanese-specific waist circumference. The patients were classified into two groups based on their VO2 at the DPBP (Low and High). Logistic regression models were applied with the high fitness group as a reference. The results showed a correlation between VO2 at the DPBP and VO2max (r=0.28; p=0.01). The age-adjusted VO2 at the DPBP was related to MS with an odds ratio (OR) of 2.58 and 95% confidence interval (CI) of 1.07-6.25 in the Low group. The OR became non-significant after further adjustment for the visceral fat area (VFA; OR=2.03, 95% CI, 0.74-5.62 in the Low group). Similar results were observed between VO2max and the prevalence of MS. This cross-sectional analysis demonstrated that VO2 at the DPBP and VO2max contributed to the prevalence of MS, but VFA cancelled out both associations. Intervention or prospective study is needed to elucidate the relative contribution of EF or VFA to MS.