二甲双胍是治疗糖尿病最常用的处方药。新出现的证据表明,二甲双胍可能具有脱靶效应,可能有助于促进健康的肌肉衰老,但是,这些影响尚未在葡萄糖耐受的老年人中进行彻底研究。这项研究的目的是研究服用二甲双胍对健康老年人骨骼肌线粒体生物能学的短期影响。
我们从16名健康的老年人中获取了肌肉活检样本,这些健康的老年人先前未使用二甲双胍并接受了二甲双胍治疗(METF;3F,5M),或安慰剂(CON;3F,5M),使用随机和盲法研究设计,为期两周。使用高分辨率呼吸测量法分析样品,免疫荧光,和免疫印迹来评估肌肉线粒体生物能学,卫星小区(SC)内容,和相关的蛋白质标记。
我们发现与CON相比,二甲双胍治疗不会改变肌肉中的最大线粒体呼吸速率。相比之下,来自METF和CON的肌肉样品中线粒体H2O2的发射和产生升高(METF发射:2.59±0.72SEFold,P=0.04;METF产量:2.29±0.53SEFold,P=0.02)。此外,H2O2排放的变化与1型肌纤维SC含量的变化呈正相关,这在METF参与者中存在偏差(Pooled:R2=0.5816,P=0.0006;METF:R2=0.674,P=0.0125).
这些研究结果表明,急性暴露于二甲双胍不会影响老年人的线粒体呼吸,糖耐量肌肉,而是,影响线粒体自由基和SC动力学。
NCT03107884,clinicaltrials.gov.
Metformin is the most commonly prescribed medication to treat diabetes. Emerging evidence suggests that metformin could have off target effects that might help promote healthy muscle aging, but these effects have not been thoroughly studied in glucose tolerant older individuals. The purpose of this
study was to investigate the short-term effects of metformin consumption on skeletal muscle mitochondrial bioenergetics in healthy older adults.
We obtained muscle biopsy samples from 16 healthy older adults previously naïve to metformin and treated with metformin (METF; 3F, 5M), or placebo (CON; 3F, 5M), for two weeks using a randomized and blinded
study design. Samples were analyzed using high-resolution respirometry, immunofluorescence, and immunoblotting to assess muscle mitochondrial bioenergetics, satellite cell (SC) content, and associated protein markers.
We found that metformin treatment did not alter maximal mitochondrial respiration rates in muscle compared to CON. In contrast, mitochondrial H2O2 emission and production were elevated in muscle samples from METF versus CON (METF emission: 2.59 ± 0.72 SE Fold, P = 0.04; METF production: 2.29 ± 0.53 SE Fold, P = 0.02). Furthermore, the change in H2O2 emission was positively correlated with the change in type 1 myofiber SC content and this was biased in METF participants (Pooled: R2 = 0.5816, P = 0.0006; METF: R2 = 0.674, P = 0.0125).
These findings suggest that acute exposure to metformin does not impact mitochondrial respiration in aged, glucose-tolerant muscle, but rather, influences mitochondrial-free radical and SC dynamics.
NCT03107884, clinicaltrials.gov.