جستجوی مقالات مرتبط با کلیدواژه "substrate oxidation" در نشریات گروه "پزشکی"

 

Firefighters have the highest risk of on duty death due to cardiovascular disease which may be caused by excessive oxidative stress (OS). Animal studies have shown that ketone bodies may reduce OS; however, human trials are needed.

To examine the effects of a supplement containing ketone salts (KS) on blood OS and cardiorespiratory responses in firefighters exercising in personal protective equipment.

Nine firefighters supplemented with KS or a calorie- and flavor-matched placebo (PLA) twice per day for 7 days in a randomized, crossover design. On the eighth day, firefighters arrived for testing after ≥ 8 hour fast and ingested the assigned supplement 35 minutes before performing the exercise task (35 minutes at 60% VO2peak intensity) wearing personal protective equipment (i.e., turnout gear, self-contained breathing apparatus, air tank, gloves). Blood was sampled pre- and post-exercise (post periods: immediately, 30 minutes and 24 hours) and analyzed for markers of OS including red blood cell (RBC) levels of glutathione (GSH), oxidized glutathione, superoxide dismutase (SOD), as well as plasma levels of SOD, catalase, total antioxidant capacity, malondialdehyde, and glucose.

There was no treatment effect or treatment × time interaction (P > 0.05) for any of the markers of OS. However, the exercise protocol resulted in significant increases in RBC levels of SOD from pre- to immediately post-exercise and decreased RBC levels of GSH from pre- to 30 minutes post-exercise. Ingestion of KS resulted in a significant increase in ketone levels and reduction in heart rate during the exercise test.

These findings suggest that 7 days of supplementation with a KS supplement does not impact markers of OS but reduces heart rate.

Type 2 diabetes and obesity are related to other metabolic disorders such as insulin resistance, high blood pressure, visceral obesity increase and metabolic syndrome with high danger of cardiovascular disease expansion.. This study aimed to determine whether in patients with type 2 diabetes, substrate oxidation and energy expenditure were affected by the type of intensity of acute aerobic exercise they were provided.. Nine men with type 2 diabetes (Mean ± SD; age 52.6 ± 0.36 years, Body Mass Index (BMI) = 30.3 ± 2.4) and 9 obese control group (Mean ± SD; age 49.1 ± 1.4 years, BMI = 31.3 ± 1.8) were participated in this study. In the first session, anthropometric measurements, body composition and maximum oxygen uptake (VO2 peak) were measured in all subjects. In the next sessions, subjects completed two acute aerobic exercises on separate days in a crossover design. The two exercise trials performed at intensity of 60% and 80% VO2 peak after fasting for at least 10 hours. Means of volume of oxygen (VO2) and Volume of Carbon dioxide (VCO2) were calculated during 30 minutes for measuring the rates of fat oxidation, carbohydrate oxidation and energy expenditure at each intensity.. The results showed that substrate oxidation and energy expenditure were lower in the diabetic group (P < 0.05) compared to the control one. Also, the results revealed that carbohydrate oxidation and energy expenditure were statistically increased by providing high intensity rather than moderate intensity; however, fat oxidation was statistically increased by providing moderate intensity rather than high intensity (P < 0.05).. According to the results of the present study, aerobic exercise at moderate intensity and proper time can be considered as a special treatment to prevent diabetes complications and related disorders, particularly obesity..