Carbon Monoxide and Exercise Prevents Diet-Induced Obesity and Metabolic Dysregulation Without Affecting Bone.
- 作者列表："Gasier HG","Yu T","Swift JM","Metzger CE","McNerny EM","Swallow EA","Piantadosi CA","Allen MR
OBJECTIVE:Carbon monoxide (CO) may counteract obesity and metabolic dysfunction in rodents consuming high-fat diets, but the skeletal effects are not understood. This study investigated whether low-dose inhaled CO (250 ppm) with or without moderate intensity aerobic exercise (3 h/wk) would limit diet-induced obesity and metabolic dysregulation and preserve bone health. METHODS:Obesity-resistant (OR) rats served as controls, and obesity-prone (OP) rats were randomized to sedentary, sedentary plus CO, exercise, or CO plus exercise. For 10 weeks, OP rats consumed a high-fat, high-sucrose diet, whereas OR rats consumed a low-fat control diet. Measurements included indicators of obesity and metabolism, bone turnover markers, femoral geometry and microarchitecture, bone mechanical properties, and tibial morphometry. RESULTS:A high-fat, high-sucrose diet led to obesity, hyperinsulinemia, and hyperleptinemia, without impacting bone. CO alone led only to a modest reduction in weight gain. Exercise attenuated weight gain and improved the metabolic profile; however, bone fragility increased. Combined CO and exercise led to body mass reduction and a metabolic state similar to control OR rats and prevented the exercise-induced increase in bone fragility. CONCLUSIONS:CO and aerobic exercise training prevent obesity and metabolic sequelae of nutrient excess while stabilizing bone physiology.
目的: 一氧化碳 (CO) 可以对抗高脂饮食啮齿类动物的肥胖和代谢功能障碍，但其对骨骼的影响尚不清楚。本研究调查了低剂量吸入 CO (250 ppm) 伴或不伴中等强度有氧运动 (3 h/wk) 是否会限制饮食诱导的肥胖和代谢失调，并保持骨骼健康。 方法: 肥胖抵抗 (OR) 大鼠作为对照，肥胖倾向 (OP) 大鼠随机分为久坐、久坐加 CO 、运动或 CO 加运动。10 周，OP 大鼠摄入高脂肪、高蔗糖饮食，而 OR 大鼠摄入低脂对照饮食。测量包括肥胖和代谢指标、骨转换标志物、股骨几何形状和微结构、骨力学性能和胫骨形态计量学。 结果: 高脂肪、高蔗糖饮食导致肥胖、高胰岛素血症和高瘦素血症，而不影响骨。CO 单独仅导致体重增加适度减少。运动可减少体重增加，改善代谢状况; 然而，骨脆性增加。联合 CO 和运动导致体质量减少和类似对照或大鼠的代谢状态，并防止运动引起的骨脆性增加。 结论: CO 和有氧运动训练在稳定骨生理的同时预防肥胖和营养过剩的代谢后遗症。
METHODS:Maintaining adequate daily protein intake is important to maintain muscle mass throughout the lifespan. In this regard, the overnight period has been identified as a window of opportunity to increase protein intake in the elderly. However, it is unknown whether pre-sleep protein intake affects next-morning appetite and, consequently, protein intake. Therefore, the purpose of the current study was to investigate the effects of a pre-sleep protein drink on next-morning appetite, energy intake and metabolism. Twelve older individuals (eight males, four females; age: 71.3 ± 4.2 years) took part in a single-blind randomised cross-over study. After a standardised dinner, participants consumed either a 40-g protein drink, isocaloric maltodextrin drink, or placebo water control before bedtime. Next-morning appetite, energy intake, resting metabolic rate (RMR), respiratory exchange rate (RER), and plasma acylated ghrelin, leptin, glucose, and insulin concentrations were assessed. No between-group differences were observed for appetite and energy intake at breakfast. Furthermore, RMR, RER, and assessed blood markers were not significantly different between any of the treatment groups. Pre-sleep protein intake does not affect next-morning appetite and energy intake and is therefore a viable strategy to increase daily protein intake in an older population.
METHODS:Leptin (LEP) regulates glucose metabolism and energy storage in the body. Osteoarthritis (OA) is associated with the upregulation of serum LEP. LEP promoter methylation is associated with obesity. So far, few studies have explored the association of BMI and OA with LEP methylation. We assessed the interaction between body mass index (BMI) and OA on LEP promoter methylation. Data of 1114 participants comprising 583 men and 558 women, aged 30−70 years were retrieved from the Taiwan Biobank Database (2008−2015). Osteoarthritis was self-reported and cases were those who reported having ever been clinically diagnosed with osteoarthritis. BMI was categorized into underweight, normal weight, overweight, and obesity. The mean LEP promoter methylation level in individuals with osteoarthritis was 0.5509 ± 0.00437 and 0.5375 ± 0.00101 in those without osteoarthritis. The interaction between osteoarthritis and BMI on LEP promoter methylation was significant (p-value = 0.0180). With normal BMI as the reference, the mean LEP promoter methylation level was significantly higher in obese osteoarthritic individuals (β = 0.03696, p-value = 0.0187). However, there was no significant association between BMI and LEP promoter methylation in individuals without osteoarthritis, regardless of BMI. In conclusion, only obesity was significantly associated with LEP promoter methylation (higher levels) specifically in osteoarthritic patients.
METHODS:Background For the same BMI, South Asians have a higher body fat percentage, a higher liver fat content and a more adverse metabolic profile than whites. South Asians may have a lower fat oxidation than whites, which could result in an unfavorable metabolic profile when exposed to increased high-fat foods consumption and decreased physical activity as in current modern lifestyle. Objective To determine substrate partitioning, liver fat accumulation and metabolic profile in South Asian and white men in response to overfeeding with high-fat diet under sedentary conditions in a respiration chamber. Design Ten South Asian men (BMI, 18–29 kg/m^2) and 10 white men (BMI, 22–33 kg/m^2), matched for body fat percentage, aged 20–40 year were included. A weight maintenance diet (30% fat, 55% carbohydrate, and 15% protein) was given for 3 days. Thereafter, a baseline measurement of liver fat content (1H-MRS) and blood parameters was performed. Subsequently, subjects were overfed (150% energy requirement) with a high-fat diet (60% fat, 25% carbohydrate, and 15% protein) over 3 consecutive days while staying in a respiration chamber mimicking a sedentary lifestyle. Energy expenditure and substrate use were measured for 3 × 24-h. Liver fat and blood parameters were measured again after the subjects left the chamber. Results The 24-h fat oxidation as a percentage of total energy expenditure did not differ between ethnicities ( P = 0.30). Overfeeding increased liver fat content ( P = 0.02), but the increase did not differ between ethnicities ( P = 0.64). In South Asians, overfeeding tended to increase LDL-cholesterol ( P = 0.08), tended to decrease glucose clearance ( P = 0.06) and tended to elevate insulin response ( P = 0.07) slightly more than whites. Conclusions Despite a similar substrate partitioning and similar accretion of liver fat, overfeeding with high-fat under sedentary conditions tended to have more adverse effects on the lipid profile and insulin sensitivity in South Asians.