The relationship between low and asymmetric handgrip strength and low muscle mass: results of a cross-sectional study on health and aging trends in western China.

OBJECTIVE: The aim was to determine the relationship between low handgrip strength (HGS) only, asymmetric HGS only, and low HGS combined with asymmetric HGS and low muscle mass in the West China Health and Aging Trends Study (WCHAT) data. STUDY DESIGN: Individuals aged at least 50 years old were included in this cross-sectional study using WCHAT data. Demographic characteristics, such as age, marital status, education level, ethnicity, and drinking and smoking history, as well as chronic diseases, were recorded for all participants. The HGS of both hands was tested three times using a grip dynanometer with the participant in a standing position with arms extended, before recording the maximum value for both hands. The maximum value referred to values < 28 kg and < 18 kg for males and females, respectively. HGS ratios (non-dominant HGS/dominant HGS) of < 0.90 or > 1.10 suggest asymmetric HGS. The subjects were then allocated to the low HGS, asymmetrical HGS, and combined low and asymmetrical HGS (BOTH group) groups, and those with neither low nor asymmetric HGS (the normal group). The InBody 770 instrument was used for the analysis of muscle mass, with low muscle mass defined as a skeletal muscle mass index (SMI) of < 7.0 kg/m2 or < 5.7 kg/m2 for males and females, respectively. The associations between the different HGS groups and low muscle mass were assessed by logistic regression analysis. RESULTS: The study included 1748 subjects, of whom 1272 (72.77%) were over the age of 60 years. The numbers of Han, Tibetan, and Qiang were 885 (50.63%), 217 (12.41%), and 579 (33.12%), respectively. A total of 465 individuals (26.60%) were classified as having low muscle mass, while 228 (13.04%), 536 (30.66%), and 125 (7.15%) participants were allocated to the low HGS, asymmetric HGS, and BOTH groups, respectively. The average SMI differed significantly between the normal group and the other groups (normal group vs. asymmetric HGS group vs. low HGS group vs. BOTH group: 6.627 kg/m2 vs. 6.633 kg/m2 vs. 6.492 kg/m2 vs. 5.995 kg/m2, respectively, P < 0.05). In addition, the prevalence of low muscle mass in the normal, asymmetric HGS, low HGS, and BOTH groups increased sequentially, with significant differences (normal group vs. asymmetric HGS group vs. low HGS group vs. BOTH group: 21.5% vs. 22.4% vs. 39.5% vs. 56%, respectively, P = 0.001). Further logistic regression analysis showed that the presence of low HGS (OR = 1.7, 95%CI: 1.203-2.402) and both low and asymmetric HGS (OR = 3.378, 95%CI: 2.173-5.252) were predictive of low muscle mass, with the chance being higher for the latter condition. CONCLUSION: The findings suggest that although asymmetrical HGS itself does not increase the chances of low muscle mass. When low HGS and a combination of both features (low HGS combined with asymmetric HGS) is present in subjects, the chance of low muscle mass increases.

Relationship between neck vessel abnormalities and sarcopenia: results of a study examining trends in health and aging in western China.

OBJECTIVE: To elucidate the association between cervical vascular abnormalities (high Crouse score, high carotid intima-media thickness [CIMT], high plaque score [PS]) and sarcopenia and its diagnostic elements. STUDY DESIGN: This cross-sectional investigation selected patients from the Western China Health and Aging Trends Study (WCHAT) aged 60 years and older. High CIMT and high Crouse score was defined as values ≥ upper quartile cutoff. Moreover, PS ≥ 3 was set as an high PS. Sarcopenia diagnosis and the definition of sarcopenia diagnostic elements were based on the Asian Working Group on Sarcopenia (AWGS) 2019 consensus. Lastly, associations between high Crouse score, high PS, high CIMT, and sarcopenia and its diagnostic elements were assessed using logistic regression. RESULT: In all, we recruited 932 subjects in this study, among which, 138 people (14.81%) were diagnosed with sarcopenia. The rates of high Crouse score (sarcopenia vs. non-sarcopenia: 37.68% vs. 23.30%, P < 0.001) and high PS (sarcopenia vs. non-sarcopenia: 34.78% vs. 18.39%, P < 0.001) in subjects with sarcopenia were higher than those in subjects without sarcopenia. Logistic regression analysis and the correction of possible confounding factors showed that high Crouse score and high PS were related to sarcopenia (high Crouse score: OR = 1.573; 95%CI: 1.032-2.4; high PS: OR = 1.845; 95%CI: 1.195-2.851). Further analysis indicated that high Crouse score were associated with low muscle mass (OR = 1.403; 95%CI: 1.002-1.966) and low physical function (OR = 1.93; 95%CI: 1.3-2.866). High PS was found to be related to low physical function (OR = 1.83; 95%CI: 1.209-2.771). CONCLUSION: While both high Crouse score and high PS are related to sarcopenia, further analysis showed that high Crouse score were mainly associated with low muscle mass and low physical function while high PS was associated with low physical function.

Suitable ultrasound screening method for older adults with disability to identify low muscle mass.

Objective: This study aimed to investigate the accuracy and consistency of different ultrasound protocols for the measurement of gastrocnemius muscle (GM) thickness and to identify a suitable ultrasound scheme that can be used to detect the low muscle mass in older with disability. Materials and methods: In this cross-sectional study, each participant underwent three different ultrasound protocols for the measurement of the GM thickness, and each measurement was repeated three times. The three measurement schemes were as follows: method A, lying on the examination bed in a prone position with legs stretched and relaxed and feet hanging outside the examination bed; method B, lateral right side lying position with legs separated (left leg flexed and right leg in a relaxed state); and method C, right side lying position with legs together and lower limb muscles in a relaxed state. The low muscle mass was determined by averaging two or three measurements of the GM thickness determined using different sonographic protocols. Results: The study included 489 participants. The difference in the prevalence of low muscle mass identified between two and three replicates of the same measurement protocol ranged from 0 to 1.3%. Considering the three repeated measurements of the method A as the reference, the area under the curve (AUC) in different measurement schemes were 0.977-1 and 0.973-1 in males and females, respectively. Furthermore, male and female Kappa values from low to high were 0.773, 0.801, 0.829, 0.839, and 0.967 and 0.786, 0.794, 0.804, 0.819, and 0.984, respectively. Conclusion: Different ultrasound measurement protocols showed high accuracy and consistency in identifying low muscle mass. Repeating the measurements two or three times was found to be feasible.