Calf circumference as a screening tool for low skeletal muscle mass: Cut-off values in independent Thai older adults.

BACKGROUND: Calf circumference is recommended as a marker for low muscle mass and as a case finding in the diagnosis of sarcopenia. However, the cut-off value differed by ethic and region. Currently there is no study among Thai population. Therefore, we aimed to identify the optimal cutoff value of calf circumference as a screening tool for low skeletal muscle mass in independent Thai older adults. Subgroup analysis was performed for obesity and adults over 75 years. METHODS: This cross-sectional cohort studied in an outpatient geriatric check-up clinic. Participants, aged 60 and above, needed to be independent in basic activities of daily living to meet the inclusion criteria. Exclusion criteria comprised active malignancy, cardiac, pulmonary, or neurovascular diseases necessitating hospitalization in the preceding three months, chronic renal diseases requiring renal replacement therapy, and unstable psychiatric disorders. We measured the maximum calf circumference and appendicular skeletal muscle mass (ASMI) using bioelectrical impedance analysis (BIA). Low muscle mass is defined according to the Asian Working Group of Sarcopenia (AWGS) 2019 consensus. RESULTS: We enrolled 6,404 elderly adults (mean age 67.3 ± 5.1 years), with a 47% prevalence of low muscle mass in women and 25% in men. Lower muscle mass significantly correlated with reduced BMI and waist circumference in both genders (p < 0.001). Optimal cut-off values for low muscle mass screening were < 33 cm (sensitivity 80.1%, specificity 60.5%) for women and < 34 cm (sensitivity 85.4%, specificity 70.2%) for men. Subgroup analysis for those with BMI ≥ 25 kg/m² suggested raising the cut-off for women to < 34 cm (sensitivity 80.6%, specificity 54.0%) and for men to < 35 cm (sensitivity 88.7%, specificity 55.2%) to enhance specificity without substantial sensitivity loss. In the older-old adult subgroup (≥ 75 years), optimal cut-off values were < 33 cm (sensitivity 84.6%, specificity 79.9%) for women and < 34 cm (sensitivity 75.6%, specificity 87.0%) for men. CONCLUSIONS: There is a strong correlation between calf circumference and ASMI in independent Thai older adults. Calf circumference can serve as a screening tool for identifying low muscle mass. The recommended cut-off values for men and women are 34 cm and 33 cm, respectively in alignment with AWGS 2019 recommendation. Incorporating a 1-cm higher cut-off value for obese older adults improves the accuracy of muscle mass screening. TRIAL REGISTRATION: Thai clinical trial registry: TCTR20200511003.

Prevalence of pre-sarcopenia among postmenopausal women younger than 65 years.

OBJECTIVE: Sarcopenia is associated with high morbidity and mortality in older women. Early detection and intervention during the postmenopausal period were hypothesized to help maintain muscle mass and performance. Although the Asian Working Group has developed guidelines for sarcopenia management, the condition has not been sufficiently investigated in the middle-aged cohort of the Asian population. This study aimed to measure the prevalence of pre-sarcopenia and sarcopenia in middle-aged postmenopausal women and to determine the factors associated with low muscle mass. METHODS: In this cross-sectional study conducted in the Menopause Clinic, King Chulalongkorn Memorial Hospital, we used the bioelectrical impedance analysis method to determine the appendicular muscle mass using a body composition analyzer (TANITA MC980 Plus). Appendicular muscle mass index, handgrip strength, and 6-m gait speed were measured in 340 women aged 45 to 65 years. Hormonal profiles, anthropometric data, and relevant history were recorded. RESULTS: The mean age of the study participants and time since menopause were 57.8 ±â€Š4.5 years and 9.4 ±â€Š5.5 years, respectively. The proportion of pre-sarcopenic, sarcopenic, and nonsarcopenic women were 11.8%, 2.7%, and 85.6%, respectively. A body mass index ≤ 20 kg/m2 had the strongest correlation with low muscle mass (odds ratio 7.1; 95% confidence interval 3.0-16.8, P < 0.001). CONCLUSION: Nearly 12% of Thai middle-aged postmenopausal women were pre-sarcopenic. Early detection of symptoms of pre-sarcopenia and maintenance of a healthy body mass index may reduce the burden of this condition for middle-aged and older women.