Pathak Kaveri, Soares Mario J, Zhao Yun, James Anthony P, Sherriff Jillian L, Newsholme Philip
Food, Nutrition & Health, School of Public Health, Curtin Health Innovation Research Institute, Faculty of Health Sciences, Curtin University, Perth, Western Australia.
Food, Nutrition & Health, School of Public Health, Curtin Health Innovation Research Institute, Faculty of Health Sciences, Curtin University, Perth, Western Australia.
Nutrition. 2017 May;37:37-42. doi: 10.1016/j.nut.2016.12.007. Epub 2016 Dec 26.
Metabolic inflexibility due to insulin resistance has been reported in metabolic syndrome (MetS). Fibroblast growth factor 21 (FGF21) and vitamin D status may improve insulin sensitivity. The aim of this study was to investigate glucose-induced thermogenesis and oxidation in MetS, and to examine whether changes in FGF21 or prevailing vitamin D status modulated defined metabolic parameters.
Forty-eight overweight and obese older adults (14 men, 34 women; ages 51 ± 15 y) were studied. Resting metabolic rate (RMR) and respiratory quotient (RQ) were measured before and intermittently for 2 h after an oral glucose tolerance test (OGTT). The total area under the curve (TAUC) was calculated. Insulin sensitivity index (ISI) was determined as 10/(insulin × glucose) for fasting and 2 h venous blood. Fat mass (FM) and fat free mass (FFM) were measured by dual-energy x-ray absorptiometry. Participants were grouped by metabolic syndrome (MetS+ for disease presence; MetS- when no disease was present) and by median 25 hydroxyvitamin D (OHD) concentration as VD_low and VD_high. 25 OHD was also tested as a continuous variable. A parsimonious 2 × 2 analysis of variance included age, FM, FFM and MetS × sex interaction.
Adjusted RMR was similar between groups but an interactive effect of MetS and sex was noted. Fasting RQ was significantly different between vitamin groups (VD_low: 0.835 ± 0.008 versus VD_high: 0.810 ± 0.008; P = 0.024) and fasting ISI was significantly greater in MetS- compared with MetS+ (P = 0.037). Postglucose increases in thermogenesis, RQ, and FGF21 were significant, but ISI decreased. Adjusted postprandial TAUC_RQ (VD_low: 1.71 ± 0.01; VD_high: 1.74 ± 0.001; P = 0.041) and ISI_2 h (VD_low: 35.41 ± 0.21; VD_high: 101.90 ± 0.21; P = 0.001) were significantly different. Adjusted FGF21 was similar across all comparisons before and after OGTT.
Higher vitamin D status, but not FGF21, was associated with greater postprandial glucose oxidation and improved insulin sensitivity.
据报道，代谢综合征（MetS）患者存在因胰岛素抵抗导致的代谢灵活性受损。成纤维细胞生长因子21（FGF21）和维生素D状态可能改善胰岛素敏感性。本研究旨在调查MetS患者中葡萄糖诱导的产热和氧化情况，并检验FGF21的变化或当前维生素D状态是否调节特定的代谢参数。
对48名超重和肥胖的老年人（14名男性，34名女性；年龄51±15岁）进行了研究。在口服葡萄糖耐量试验（OGTT）前及试验后2小时内间歇性测量静息代谢率（RMR）和呼吸商（RQ）。计算曲线下总面积（TAUC）。空腹和2小时静脉血的胰岛素敏感性指数（ISI）按10/（胰岛素×葡萄糖）计算。通过双能X线吸收法测量脂肪量（FM）和去脂体重（FFM）。参与者按代谢综合征（存在疾病为MetS+；无疾病为MetS-）以及按25羟维生素D（OHD）浓度中位数分为VD低组和VD高组。25 OHD也作为连续变量进行检测。一个简约的2×2方差分析纳入了年龄、FM、FFM以及MetS×性别交互作用。
调整后的RMR在各组之间相似，但注意到MetS和性别的交互作用。维生素组之间空腹RQ有显著差异（VD低组：0.835±0.008，VD高组：0.810±0.008；P = 0.024），且MetS-组的空腹ISI显著高于MetS+组（P = 0.037）。葡萄糖摄入后产热、RQ和FGF21的增加显著，但ISI下降。调整后的餐后TAUC_RQ（VD低组：1.71±0.01；VD高组：1.74±0.001；P = 0.041）和ISI_2小时（VD低组：35.41±0.21；VD高组：101.90±0.21；P = 0.001）有显著差异。OGTT前后所有比较中调整后的FGF21相似。
较高的维生素D状态而非FGF21与餐后葡萄糖氧化增加和胰岛素敏感性改善相关。
