Lower aerobic capacity was associated with abnormal intramuscular energetics in patients with metabolic syndrome

Abstract

Lower aerobic capacity is a strong and independent predictor of cardiovascular morbidity and mortality in patients with metabolic syndrome (MetS). However, the mechanisms are not fully elucidated. We tested the hypothesis that skeletal muscle dysfunction could contribute to the lower aerobic capacity in MetS patients. The incremental exercise tests with cycle ergometer were performed in 12 male patients with MetS with no habitual exercise and 11 age-, sex-and activity-matched control subjects to assess the aerobic capacity. We performed 31 phosphorus-magnetic resonance spectroscopy (MRS) to assess the high-energy phosphate metabolism in skeletal muscle during aerobic exercise. Proton-MRS was also performed to measure intramyocellular lipid (IMCL) content. Peak oxygen uptake (peak VO 2 ; 34.1±6.2 vs. 41.4±8.4 ml kg À1 min À1 , Po0.05) and anaerobic threshold (AT; 18.0±2.4 vs. 23.1±3.7 ml kg À1 min À1 , Po0.01) adjusted by lean body mass were lower in MetS patients than control subjects. Phosphocreatine (PCr) loss during exercise was 1.5-fold greater in MetS, suggesting reduced intramuscular oxidative capacity. PCr loss was inversely correlated with peak VO 2 (r¼À0.64) and AT (r¼À0.60), respectively. IMCL content was threefold higher in MetS and was inversely correlated with peak VO 2 (r¼À0.47) and AT (r¼À0.52), respectively. Moreover, there was a positive correlation between IMCL content and PCr loss (r¼0.64). These results suggested that lean-body aerobic capacity in MetS patients was lower compared with activity-matched healthy subjects, which might be due to the reduced intramuscular fatty acid oxidative metabolism.

Effects of Different Exercise Modes on the Urinary Metabolic Fingerprint of Men with and without Metabolic Syndrome

“…In fact, lean body aerobic capacity was significantly lower in sedentary men with MetS, compared to controls with matched levels of physical activity [30]. A delimitation of our study, then, was that participants exercised at the same relative, rather than absolute, intensity, which we deemed a “fairer” comparison.…”

The effects of exercise training and caloric restriction on the cardiac oxytocin natriuretic peptide system in the diabetic mouse

“…Epidemiological studies unequivocally indicate that exercise training (ET) is an effective method in improving blood glucose regulation, insulin resistance, blood lipids, and blood pressure 5–7. The limited exercise capacity and impaired energy metabolism can also be improved, delaying the onset and progression of cardiovascular disease in patients with type 2 diabetes 8,9. In addition to exercise, a great body of evidence has shown that limiting food intake is an effective frontline strategy to reduce cardiometabolic risk and disorders 10,11.…”

Effect of Pole-Assisted Walking on Intramuscular Lipids in Elderly Nursing Home Residents

“…Spectra were line broadened and phase and baseline corrected, and the resonances of interest were line fit at a mixed Lorentzian/Gaussian function. After correction for T1 and T2 relaxations, quantification of IMCL and EMCL content was carried out to compare intensity of (CH2) n (methylene) at 1.3 ppm and 1.5 ppm resonance to the water resonance intensity at 4.7 ppm (Figure 1) [15][16][17][18]. The IMCL and EMCL values were corrected for multiple CH 2 groups by using the methods described by Szczepaniak et al [4].…”