Physical Activity, Sport and Recreation Research Focus Area, Faculty of Health Sciences, North-West University, Potchefstroom2520, South Africa.
School of Nursing and Public Health, Faculty of Health Sciences and Veterinary Medicines, University of Namibia, Windhoek, Namibia.
Br J Nutr. 2023 Oct 28;130(8):1437-1443. doi: 10.1017/S0007114523000387. Epub 2023 Mar 9.
This study aimed to assess the validity of mid-arm circumference (MAC), also known as mid-upper arm circumference (MUAC), for classification of high body fatness in Namibian adolescent girls and women and to test whether classification accuracy of MUAC was higher than the traditional simple proxy for high fatness, the BMI. In 206 adolescent girls aged 13-19 years and 207 adult women aged 20-40 years, we defined obesity conventionally (BMI-for-age Z score ≥ 2·00, adolescents; adults BMI ≥ 30·0 kg/m) and also defined obesity using published MAC cut-off values. H oxide dilution was used to measure total body water (TBW) to define high body fat percentage (≥ 30 % in the adolescents, ≥ 38 % in the adults), and we compared the ability of BMI and MAC to classify high body fatness correctly using sensitivity, specificity and predictive values. In the adolescents, obesity prevalence was 9·2 % (19/206) using BMI-for-age and 63·2 % (131/206) using TBW; sensitivity of BMI-for-age was 14·5 % (95 % CI 9·1, 22·0 %) but was improved significantly using MAC of 22·6 cm (sensitivity 96·9 %; 95 % CI 92·1 %, 99·3 %). In the adults, obesity prevalence was 30·4 % (63/207) using BMI and 57·0 % (118/207) using TBW, and sensitivity of BMI was 52·5 % (95 % CI 43·6, 62·2 %), but using a MAC of 30·6 cm sensitivity was 72·8 % (95 % CI 66·4, 82·6 %). Surveillance of obesity in African adolescent girls and adult women is likely to be improved substantially by use of MAC as an alternative to the BMI-for-age and BMI.
本研究旨在评估中臂围（MAC），又称上臂中部围（MUAC），在判定纳米比亚青少年女性体脂过高方面的有效性，并检验 MUAC 分类的准确性是否高于传统的体脂过高简单替代指标 BMI。在 206 名年龄在 13-19 岁的青少年和 207 名年龄在 20-40 岁的成年女性中，我们采用传统标准（青少年 BMI-年龄 Z 分数≥2.00，成年人 BMI≥30.0kg/m2）和已发表的 MAC 截断值来定义肥胖。使用氢氧化物稀释法测量全身水（TBW）来定义高体脂百分比（青少年≥30%，成年人≥38%），我们比较了 BMI 和 MAC 正确分类高体脂的能力，采用敏感性、特异性和预测值进行比较。在青少年中，使用 BMI-年龄来定义肥胖的患病率为 9.2%（19/206），使用 TBW 来定义肥胖的患病率为 63.2%（131/206）；BMI-年龄的敏感性为 14.5%（95%CI9.1-22.0%），但使用 MAC 为 22.6cm 后显著提高（敏感性 96.9%；95%CI92.1%-99.3%）。在成年人中，使用 BMI 来定义肥胖的患病率为 30.4%（63/207），使用 TBW 来定义肥胖的患病率为 57.0%（118/207），BMI 的敏感性为 52.5%（95%CI43.6%-62.2%），但使用 MAC 为 30.6cm 后敏感性提高至 72.8%（95%CI66.4%-82.6%）。在非洲青少年女性和成年女性中，使用 MAC 替代 BMI-年龄和 BMI 来监测肥胖，可能会显著提高肥胖的监测效果。
