Assessing body composition in older adults: comparing BMI, Calf circumference, and DXA

Introduction: This research aimed to investigate the possible correlation between body mass index (BMI), left calf circumference (CC), and dual-energy X-ray absorptiometry (DXA). Objective: After the sampling process, 287 participants (X = 66.50 5.75 years) residing in Aracaju, Brazil, were selected and assisted by the Augusto Franco and Antônio Alves Basic Health Units (UBS). The International Standards for Anthropometric Assessment procedures measured body mass and height. Methodology: The intraclass correlation coefficient (ICC) was used to assess the reliability of anthropometric measurements. Pearson's correlation test investigated the associations between DXA, BMI, and CC variables. The coefficient of determination (r2) was used to verify the explanatory power between the study variables. The level of p < 0.05 was considered for statistical significance. Results: the correlation between DXA and BMI observed a positive, high, and significant correlation (r = 0.928, p<0.001) between the two parameters; a positive, moderate, and significant correlation was identified between CC and DXA (r = 0.641, p<0.001); and a moderate, and significant correlation was shown between CC and BMI (r = 0.648, p<0.001). Conclusion: The correlations were positive between BMI and DXA, which were strong, and CC and DXA, which were moderate, showing that both methods can be applied for body composition assessment in older people due to ease and low cost.