O073 - NEW CUTOFF POINTS AND ADJUSTMENT FACTORS FOR ARM CIRCUMFERENCE AS A MUSCLE MASS MARKER

O073

NEW CUTOFF POINTS AND ADJUSTMENT FACTORS FOR ARM CIRCUMFERENCE AS A MUSCLE MASS MARKER

J. P. Costa-Pereira^1,*, C. M. Prado², S. B. Heymsfield³, A. P. T. Fayh⁴, P. C. Cabral¹, M. C. Gonzalez⁵

¹Nutrition, UFPE, Recife, Brazil, ²HNRU, University of Alberta, Edmonton, Canada, ³Pennington Biomedical Research Center, LSU System, Baton Rouge, United States, ⁴Nutrition, UFCSPA, Porto Alegre, ⁵UFPEL, Pelotas, Brazil

Rationale: Mid-upper arm circumference (MUAC) is a potential marker of muscle mass and has been endorsed as a phenotypic criterion to diagnose malnutrition. However, appropriate cutoff points have not been established, nor have adjustment factors been proposed to account for excess weight.

Methods: Data from the National Health and Nutrition Examination Survey (NHANES 1999–2006) were analyzed. Body mass index (BMI), MUAC, and triceps skinfold thickness (TST) were assessed. Appendicular lean soft tissue (ALST) by dual-energy x-ray absorptiometry (DXA) served as the reference for muscle mass. Adults aged 18–39 with a normal BMI range (18.5–24.9 kg/m2) comprised the reference population to propose cutoff values. Low and very low values were defined as −1 and −2 standard deviations, respectively. BMI-adjustment factors for MUAC to predict ALST were developed using linear regression.

Results: A total of 3,185 individuals comprised the reference sample out of 18,195 evaluated participants. The proposed MUAC cutoff values for identifying low muscle mass were: <28 cm for males and <25 cm for females; very low values were defined as <26 cm for males and <23 cm for females. BMI adjustment factors for MUAC varied by sex and BMI categories: for males, −3 cm, −7 cm, and −10 cm; and for females, −2 cm, −6 cm, and −9 cm for BMI ranges of 25–29.9, 30–39.9, and ≥40 kg/m², respectively. Among individuals with excess weight, BMI-adjusted MUAC showed stronger correlations with ALST than traditional anthropometric indicators, including arm muscle circumference and mid-arm muscle area calculated from MUAC and TST.

Conclusion: Our study proposes cutoff values and BMI-adjustment factors for MUAC as a marker of muscle mass. Although pending validation, this approach shows promise as a practical bedside tool, particularly in settings where other assessments are not feasible.

Disclosure of Interest: J. P. Costa-Pereira Other: Previously received travel costs from Fresenius Kabi as part of Jumpstart Clinical Nutrition Program, C. Prado Consultant for: CMP has received honoraria and/or paid consultancy from Abbott Nutrition, Nutricia, Nestlé Health Science, Pfizer, AMRA Medical; investigator-initiated funding from Almased, and Novo Nordisk, Speakers Bureau of: CMP has received honoraria and/or paid consultancy from Abbott Nutrition, Nutricia, Nestlé Health Science, Pfizer, AMRA Medical; investigator-initiated funding from Almased, and Novo Nordisk, S. Heymsfield: None declared, A. Fayh Grant / Research Support from: Grant for research from Prodiet Medical Nutrition, P. Cabral: None declared, M. Gonzalez Consultant for: MCG has received honoraria and/or paid consultancy from Abbott Nutrition, Nutricia, and Nestlé Health Science Brazil, Speakers Bureau of: MCG has received honoraria and/or paid consultancy from Abbott Nutrition, Nutricia, and Nestlé Health Science Brazil