Hicks Gregory E, Simonsick Eleanor M, Harris Tamara B, Newman Anne B, Weiner Debra K, Nevitt Michael A, Tylavsky Frances A
PT, Department of Physical Therapy and Rehabilitation Science, University of Maryland School of Medicine, 100 Penn St., Baltimore, MD 21201, USA.
J Gerontol A Biol Sci Med Sci. 2005 Nov;60(11):1420-4. doi: 10.1093/gerona/60.11.1420.
Cross-sectionally, lower trunk muscle attenuation (higher fat infiltration) has been associated with poorer physical function in older adults. We hypothesize that lower trunk muscle attenuation will be associated with lower functional capacity 3 years later and that back pain status will moderate this relationship.
The study sample consisted of a biracial cohort of well functioning men (739) and women (788) aged 70-79 years from the Pittsburgh site of the Health, Aging and Body Composition (Health ABC) study. Computed tomography was used to measure trunk muscle area and attenuation of the lumbar paraspinal, lateral abdominal, and rectus abdominus muscles at baseline. The Health ABC Physical Performance Battery (usual and narrow walk, chair stands, and standing balance) was used to measure functional capacity at the first and fourth annual clinic visits.
Regardless of back pain status, average trunk muscle attenuation (but not muscle area) was positively associated with overall physical performance, particularly balance (p <.01), in a fully adjusted model. The association between trunk attenuation and functional capacity was significantly stronger in participants with at least moderate back pain in the year prior to baseline (p <.05 for interaction; attenuation x back pain). Participants with moderate to extreme back pain had a greater decline in function over time (p <.05).
Older adults with poorer trunk muscle composition (higher fat infiltration) exhibit reduced functional capacity, especially balance, 3 years later. Improving trunk muscle composition may be an important yet overlooked approach to maintain function and potentially reduce balance impairments, particularly in persons with a history of back pain.
横断面研究表明，老年人群体中，下躯干肌肉衰减（较高的脂肪浸润）与较差的身体功能相关。我们推测，下躯干肌肉衰减与3年后较低的功能能力相关，且背痛状况会调节这种关系。
研究样本来自健康、衰老和身体成分研究（Health ABC）匹兹堡站点的739名男性和788名女性组成的双种族队列，年龄在70 - 79岁，功能良好。在基线时，使用计算机断层扫描测量腰椎旁肌、侧腹肌和腹直肌的躯干肌肉面积和衰减情况。在首次和第四次年度门诊就诊时，使用Health ABC身体性能测试组（正常和窄道行走、从椅子上站起以及站立平衡测试）来测量功能能力。
在完全调整模型中，无论背痛状况如何，平均躯干肌肉衰减（而非肌肉面积）与总体身体性能呈正相关，尤其是平衡能力（p <.01）。在基线前一年至少有中度背痛的参与者中，躯干衰减与功能能力之间的关联显著更强（交互作用p <.05；衰减×背痛）。中度至重度背痛的参与者功能随时间下降幅度更大（p <.05）。
躯干肌肉组成较差（较高脂肪浸润）的老年人在3年后功能能力下降，尤其是平衡能力。改善躯干肌肉组成可能是维持功能并潜在减少平衡障碍的一种重要但被忽视的方法，特别是对于有背痛病史的人。
