The use of mid upper arm circumference and skinfold thickness to assess underweight and obesity among cardiac patients

Abstract

Introduction and Objectives: Assessment of nutritional status is a key element in the management of the cardiac patient. There are practical difficulties in using the conventional parameters such as Body Mass Index (BMI) and Waist Circumference (WC), especially in critically ill and bed bound patients. The current study evaluated the validity of Mid Upper Arm Circumference (MUAC) and Triceps Skinfold Thickness (TSFT) as alternatives for BMI and WC in assessing underweight, obese and centrally obese among cardiac patients. Methods: A cross-sectional study was carried out among 526 patients admitted to a tertiary care hospital. Height, weight, WC, MUAC and TSFT were measured using standard techniques. Those who had a BMI ≤18.5kgm-2 were considered as underweight and BMI>25kgm-2 as obese. Asian cut-offs (WC>90cm for males, WC>80cm for females) were used to define central obesity. Receiver operating characteristic (ROC) curve analysis was done. Results: Mean MUAC and TSFT were 29.1cm and 14.9mm respectively. MUAC had ROC curve area of 0.94 which was higher than that of TSFT (0.81). Based on the highest corresponding Youden’s Indices, MUAC<26cm, TSFT<10.1mm were found to be suitable cut-off points for the detection of underweight patients and MUAC>30cm, TSFT>13.8mm for obese. Both parameters were valid in detecting central obesity, for which MUAC>28.8, TSFT>12.8mm for males and MUAC>26.7cm, TSFT>17.4mm for females were suitable cut-offs. Conclusions: MUAC and TSFT were possible alternatives for the detection of underweight, obese and centrally obese cardiac patients. Among them, MUAC was found to be a better predictor. For simplicity in use, MUAC<26cm and >30cm can be used as cut-off points to detect underweight and obese patients respectively.

Keywords

• mid upper arm circumference, triceps skin fold thickness, cardiac, body mass index, waist circumference, overweight, obese, sri lanka