Zhao Qian, Zmuda Joseph M, Kuipers Allison L, Jonnalagadda Pallavi, Bunker Clareann H, Patrick Alan L, Youk Ada O, Miljkovic Iva
Department of Epidemiology, University of Pittsburgh, Pittsburgh, PA 15213, USA.
Tobago Health Studies Office, Scarborough, Trinidad and Tobago.
Age Ageing. 2016 Jul;45(4):529-34. doi: 10.1093/ageing/afw062. Epub 2016 Apr 13.
fat infiltration within and around skeletal muscle (i.e. myosteatosis) increases with ageing, is greater in African versus European ancestry men and is associated with poor health. Myosteatosis studies of mortality are lacking, particularly among African ancestry populations.
in the Tobago Health study, a prospective longitudinal study, we evaluated the association of all-cause mortality with quantitative computed tomography (QCT) measured lower leg myosteatosis (intermuscular fat (IM fat) and muscle density) in 1,652 African ancestry men using Cox proportional hazards models. Date of death was abstracted from death certificates and/or proxy.
one hundred and twelve deaths occurred during follow-up (mean 5.9 years). In all men (age range 40-91 years), higher all-cause mortality was associated with greater IM fat (HR (95% CI) per SD: 1.29 (1.06-1.57)) and lower muscle density (HR (95% CI) per SD lower: 1.37 (1.08-1.75)) in fully adjusted models. Similar mortality hazard rates were seen in the subset of elderly men (aged ≥65 years) with greater IM fat (1.40 (1.11-1.78) or lower muscle density (1.66 (1.24-2.21)) in fully adjusted models.
our study identified a novel, independent association between myosteatosis and all-cause mortality in African ancestry men. Further studies are needed to establish whether this association is independent of other ectopic fat depots and to identify possible biological mechanisms underlying this relationship.
骨骼肌内部及周围的脂肪浸润（即肌脂肪变性）会随着年龄增长而增加，在非洲裔男性中比欧洲裔男性更为明显，且与健康状况不佳有关。目前缺乏关于肌脂肪变性与死亡率关系的研究，尤其是在非洲裔人群中。
在多巴哥健康研究（一项前瞻性纵向研究）中，我们使用Cox比例风险模型评估了1652名非洲裔男性中全因死亡率与定量计算机断层扫描（QCT）测量的小腿肌脂肪变性（肌间脂肪（IM脂肪）和肌肉密度）之间的关联。死亡日期从死亡证明和/或代理人处获取。
随访期间有112人死亡（平均5.9年）。在所有男性（年龄范围40 - 91岁）中，在完全调整模型中，全因死亡率较高与IM脂肪增加（每标准差的HR（95%CI）：1.29（1.06 - 1.57））和肌肉密度降低（每降低一个标准差的HR（95%CI）：1.37（1.08 - 1.75））相关。在老年男性（年龄≥65岁）亚组中，完全调整模型中IM脂肪增加（1.40（1.11 - 1.78））或肌肉密度降低（1.66（1.24 - 2.21））时，观察到类似的死亡风险率。
我们的研究在非洲裔男性中发现了肌脂肪变性与全因死亡率之间一种新的独立关联。需要进一步研究以确定这种关联是否独立于其他异位脂肪储存，并确定这种关系背后可能的生物学机制。
