Murphy Rachel A, Reinders Ilse, Register Thomas C, Ayonayon Hilsa N, Newman Anne B, Satterfield Suzanne, Goodpaster Bret H, Simonsick Eleanor M, Kritchevsky Stephen B, Harris Tamara B
Laboratory of Epidemiology, and Population Sciences, Intramural Research Program, National Institute on Aging, Bethesda, MD (RAM, IR, and TBH); the Sections on Comparative Medicine Pathology, Radiology (TCR), and Gerontology and Geriatrics (SBK), Sticht Center on Aging, Wake Forest School of Medicine, Winston-Salem, NC; the Department of Epidemiology and Biostatistics, University of California, San Francisco, San Francisco, CA (HNA); the Department of Epidemiology, University of Pittsburgh, Pittsburgh, PA (ABN); the Department of Preventive Medicine, University of Tennessee Health Science Center, Memphis, TN (SS); the Center for Aging and Population Health, Department of Medicine, University of Pittsburgh, Pittsburgh, PA (BHG); and the Translational Gerontology Branch, Intramural Research Program, National Institute on Aging, Baltimore, MD (EMS).
Am J Clin Nutr. 2014 May;99(5):1059-65. doi: 10.3945/ajcn.113.080796. Epub 2014 Feb 12.
Obesity is a risk factor for disability, but risk of specific adipose depots is not completely understood.
We investigated associations between mobility limitation, performance, and the following adipose measures: body mass index (BMI) and areas and densities of visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), and intermuscular adipose tissue (IMAT) in older adults.
This was a prospective population-based study of men (n = 1459) and women (n = 1552) initially aged 70-79 y and free from mobility limitation. BMI was determined from measured height and weight. Adipose tissue area and density in Hounsfield units were measured in the thigh and abdomen by using computed tomography. Mobility limitation was defined as 2 consecutive reports of difficulty walking one-quarter mile or climbing 10 steps during semiannual assessments over 13 y. Poor performance was defined as a gait speed <1 m/s after 9 y of follow-up (n = 1542).
In models adjusted for disability risk factors, BMI, and areas of VAT, abdominal SAT, and IMAT were positively associated with mobility limitation in men and women. In women, thigh SAT area was positively associated with mobility limitation risk, whereas VAT density was inversely associated. Associations were similar for poor performance. BMI and thigh IMAT area (independent of BMI) were particularly strong indicators of incident mobility limitation and poor performance. For example, in women, the HR (95% CI) and OR (95% CI) associated with an SD increment in BMI for mobility limitation and poor performance were 1.31 (1.21, 1.42) and 1.41 (1.13, 1.76), respectively. In men, the HR (95% CI) and OR (95% CI) associated with an SD increment in thigh IMAT for mobility limitation and poor performance were 1.37 (1.27, 1.47) and 1.54 (1.18, 2.02), respectively.
Even into old age, higher BMI is associated with mobility limitation and poor performance. The amount of adipose tissue in abdominal and thigh depots may also convey risk beyond BMI.
肥胖是导致残疾的一个风险因素，但特定脂肪堆积部位的风险尚未完全明确。
我们研究了老年人行动受限、身体机能与以下脂肪测量指标之间的关联：体重指数（BMI）、内脏脂肪组织（VAT）、皮下脂肪组织（SAT）和肌间脂肪组织（IMAT）的面积及密度。
这是一项基于人群的前瞻性研究，研究对象为最初年龄在70 - 79岁且无行动受限的男性（n = 1459）和女性（n = 1552）。通过测量身高和体重来确定BMI。使用计算机断层扫描测量大腿和腹部脂肪组织的面积及以亨氏单位表示的密度。行动受限定义为在13年的半年度评估中连续两次报告行走四分之一英里或爬10级台阶有困难。身体机能差定义为随访9年后步速<1米/秒（n = 1542）。
在针对残疾风险因素、BMI以及VAT、腹部SAT和IMAT面积进行调整的模型中，男性和女性的BMI、VAT、腹部SAT和IMAT面积与行动受限呈正相关。在女性中，大腿SAT面积与行动受限风险呈正相关，而VAT密度与之呈负相关。身体机能差的情况也有类似的关联。BMI和大腿IMAT面积（独立于BMI）是行动受限和身体机能差的特别强的预测指标。例如，在女性中，与BMI每增加一个标准差相关的行动受限和身体机能差的风险比（HR，95%置信区间）及比值比（OR，95%置信区间）分别为1.31（1.21, 1.42）和1.41（1.13, 1.76）。在男性中，与大腿IMAT每增加一个标准差相关的行动受限和身体机能差的HR（95%置信区间）及OR（95%置信区间）分别为1.37（1.27, 1.47）和1.54（1.18, 2.02）。
即使到老年，较高的BMI也与行动受限和身体机能差有关。腹部和大腿部位的脂肪组织量可能也会带来超出BMI的风险。
