Measuring Muscle Post-Exercise Oxygen Consumption in Individuals with a Family History of Diabetes.

Background

Post-exercise oxygen consumption (EPOC) contributes to the health benefits of exercise, and changes in EPOC may play a role in the development of diabetes. Near-infrared spectroscopy (NIRS) is a tool used to evaluate muscle metabolism. This study used a novel NIRS-based method of measuring EPOC in the forearm muscles of young adults with and without a family history of diabetes.

Methods

Fourteen female adults with and without an immediate family history of diabetes were tested. A two-group, one-day design was used with three protocols: ischemic reperfusion, EPOC, and mitochondrial capacity. Muscle oxygen levels were measured with NIRS in the forearm. Blood flow was assessed as the initial reperfusion rate following 5 min of ischemia. EPOC was measured after 60 s of rapid wrist curls with a 2.3 kg weight, followed by measurements every minute for 10 min. Muscle mitochondrial capacity (mVO2max) was determined from the recovery rate of muscle metabolism after 30 s of electrical stimulation. EPOC was calculated as the area under the curve of oxygen consumption over 10 min after exercise, subtracting the phosphocreatine contribution calculated from mVO2max. Group comparisons were made using t-tests with significance at p < 0.05.

Results

mVO2max was not different between those with a positive (1.60 ± 0.15 min-1) and those with a negative family history (1.45 ± 0.17 min-1), p = 0.11. Net EPOC was not different between those with a positive (20.0 ± 7.2 O2·s) and those with a negative (19.6 ± 11.3 O2·s) family history, p = 0.94.

Conclusions

Muscle EPOC minus PCr was calculated after a short, intense bout of exercise. No differences were found in the mitochondrial capacity or EPOC between young healthy individuals with and without a family history of diabetes. This study presents the use of EPOC to evaluate muscle metabolism in populations at risk for diabetes and other related disorders.