Background: Sarcopenia is defined as low skeletal muscle mass (SMM) and muscle function. It is associated with adverse health outcomes such as increased falls and fracture risk; decreased bone mineral density; prolonged hospital stays; increased risk of death and disability; discharge to a facility after hospital stay; and, increased burden on the economy. 1,2,3
Aim: To examine the relationship between calf circumference (CC) and SMM and to assess the suitability of CC as a simple, clinically useful measuring tool of SMM for the diagnosis of sarcopenia in middle-aged and older women.
Methods: Data from 135 female participants aged 40-97 years old were analysed in this quantitative study. Measurements taken from each participant included anthropometry, bioelectrical impedance analysis (BIA), dual-energy X-ray absorptiometry (DEXA) and measurements of their calf, thigh and mid-upper arm circumference (cm). European cut off values1 were used to diagnose sarcopenia in our patients which include DEXA appendicular SMM / height2 <5.5kg/m2, muscle strength <20kg, and BIA skeletal muscle index/height 2 <6.42kg/m2.
Results: Forty-seven women in the study were diagnosed with sarcopenia, 77 normal SMM, and 11 had inconclusive values. Regression analysis showed the strongest relationship between appendicular SMM and lean body mass impedance, lean body mass anthropometry and CC. In receiver operating characteristic analysis, the optimal calf circumference cut-off values for predicting sarcopenia was 33.6cm (sensitivity 80.9% specificity 75.3%) with p-value = <0.01, NPV=0.866 and PPV=0.667. Ninety-one percent of patients with sarcopenia had a calf circumference <35.1cm and 90.9% of those without sarcopenia had a calf circumference above 31.6cm.
Conclusion: Calf circumference was positively correlated with appendicular SMM, with the suggested cut off value of ≤33.6cm being a good predictor for sarcopenia.