Dept of Pathology and Molecular Medicine, McMaster University, Hamilton, ON, Canada.
Dept of Pediatrics, McMaster University, Hamilton, ON, Canada.
J Clin Endocrinol Metab. 2021 Jul 13;106(8):2405-2422. doi: 10.1210/clinem/dgab261.
Previous investigations on skeletal muscle health in type 1 diabetes (T1D) have generally focused on later stages of disease progression where comorbidities are present and are posited as a primary mechanism of muscle dysfunction.
To investigate skeletal muscle function and morphology across the adult lifespan in those with and without T1D.
Participants underwent maximal contraction (MVC) testing, resting muscle biopsy, and venous blood sampling.
Procedures in this study were undertaken at the McMaster University Medical Centre.
Sixty-five healthy adult (18-78 years old) men/males and women/females (T1D = 34; control = 31) matched for age/biological sex/body mass index; self-reported physical activity levels were included.
Our primary measure in this study was MVC, with supporting histological/immunofluorescent measures.
After 35 years of age ("older adults"), MVC declined quicker in T1D subjects compared to controls. Loss of strength in T1D was accompanied by morphological changes associated with accelerated aging. Type 1 myofiber grouping was higher in T1D, and the groups were larger and more numerous than in controls. Older T1D females exhibited more myofibers expressing multiple myosin heavy chain isoforms (hybrid fibers) than controls, another feature of accelerated aging. Conversely, T1D males exhibited a shift toward type 2 fibers, with less evidence of myofiber grouping or hybrid fibers.
These data suggest impairments to skeletal muscle function and morphology exist in T1D. The decline in strength with T1D is accelerated after 35 years of age and may be responsible for the earlier onset of frailty, which characterizes those with diabetes.
之前对 1 型糖尿病（T1D）患者骨骼肌健康的研究通常集中在疾病进展的后期阶段，此时存在合并症，并被认为是肌肉功能障碍的主要机制。
研究有和没有 T1D 的个体在整个成年期的骨骼肌功能和形态。
参与者接受最大收缩（MVC）测试、静息肌肉活检和静脉采血。
本研究中的程序在麦克马斯特大学医学中心进行。
65 名健康成年（18-78 岁）男性/男性和女性/女性（T1D=34；对照=31），按年龄/生物性别/体重指数匹配；包括自我报告的身体活动水平。
本研究的主要测量指标是 MVC，并辅以组织学/免疫荧光测量指标。
在 35 岁以后（“老年人”），与对照组相比，T1D 患者的 MVC 下降更快。T1D 患者的力量丧失伴随着与加速衰老相关的形态变化。T1D 中的 1 型肌纤维群更高，并且比对照组更大、更多。与对照组相比，老年 T1D 女性表达多种肌球蛋白重链同工型的肌纤维（杂交纤维）更多，这是加速衰老的另一个特征。相反，T1D 男性表现出向 2 型纤维的转变，肌纤维群集或杂交纤维的证据较少。
这些数据表明 T1D 存在骨骼肌功能和形态的损伤。T1D 患者的力量下降在 35 岁后加速，可能是导致糖尿病患者更早出现虚弱的原因。
