Lin Chia-Shu, Liu Li-Kuo, Lee Wei-Ju, Peng Li-Ning, Lin Ching-Po, Lee Shyh-Yuan, Chen Liang-Kung
Department of Dentistry, College of Dentistry, National Yang Ming Chiao Tung University, Hsin-Chu, Taiwan.
Center for Healthy Longevity and Aging Sciences, National Yang Ming Chiao Tung University, Hsin-Chu, Taiwan; Center for Geriatrics and Gerontology, Taipei Veterans General Hospital, Taipei, Taiwan.
Exp Gerontol. 2022 Jun 15;163:111777. doi: 10.1016/j.exger.2022.111777. Epub 2022 Mar 25.
Sarcopenia, defined as age-related diminution of muscle mass and strength, is a key determinant of frailty status and progression. We investigated the hypothesis that changing masseter muscle structure with advancing age may contribute to the development of frailty.
Study data were excerpted from the I-Lan Longitudinal Aging Study, a research cohort of community-dwelling residents aged ≥53 years from Yilan (I-Lan) County, Taiwan. The study sample comprised 56 subjects classified as frail, 41 pre-frail, and 41 robust, according to Cardiovascular Health Study criteria; all groups were matched by age and sex. Masseter muscle volume was quantified based on T1-weighted magnetic resonance imaging, and adjusted for height to derive the masseter volume index (MVI). Appendicular skeletal muscle mass index (SMI) was determined by dual-energy X-ray absorptiometry, and used to derive the height-adjusted skeletal mass index (SMI). Nutrition status was assessed with the Mini-Nutritional Assessment (MNA) form.
The MVI was significantly smaller in frail versus pre-frail subjects. Among frail individuals, only the MVI was significantly correlated with MNA scores. MVI, but not SMI, was associated with increased risk of being frail versus pre-frail. An MVI cut-off score of 9.5 cm/m in males discriminated frail from pre-frail status with acceptable sensitivity and specificity. Low MVI was associated with the frailty criteria of slowness.
MVI is a potential clinical index for evaluating phenotypic frailty. Diminished masseter muscle volume may predispose pre-frail/frail elders to depletion of physical reserves, consequent to its detrimental effect on oral functioning and nutrient intake.
肌肉减少症被定义为与年龄相关的肌肉质量和力量下降，是虚弱状态和进展的关键决定因素。我们研究了随着年龄增长咬肌结构变化可能导致虚弱发展的假说。
研究数据摘自宜兰纵向老龄化研究，这是一个来自中国台湾宜兰县年龄≥53岁的社区居民研究队列。根据心血管健康研究标准，研究样本包括56名被归类为虚弱的受试者、41名虚弱前期受试者和41名健康受试者；所有组按年龄和性别匹配。基于T1加权磁共振成像对咬肌体积进行量化，并根据身高进行调整以得出咬肌体积指数（MVI）。通过双能X线吸收法测定四肢骨骼肌质量指数（SMI），并用于得出身高调整后的骨骼肌质量指数（SMI）。使用微型营养评定法（MNA）表格评估营养状况。
与虚弱前期受试者相比，虚弱受试者的MVI显著更小。在虚弱个体中，只有MVI与MNA评分显著相关。与虚弱前期相比，MVI而非SMI与虚弱风险增加相关。男性MVI截止分数为9.5 cm/m可区分虚弱和虚弱前期状态，具有可接受的敏感性和特异性。低MVI与行动迟缓的虚弱标准相关。
MVI是评估表型虚弱的潜在临床指标。咬肌体积减小可能使虚弱前期/虚弱老年人易出现身体储备耗竭，因其对口腔功能和营养摄入有不利影响。
