Accuracy of mid upper arm circumference in detection of obesity among school children in Yenagoa City, South-south region of Nigeria

Abstract

Background: The search for alternative method that is easier and less cumbersome than body mass index (BMI), for identification of obese individuals has been controversially discussed in recent literature. This study was carried out to determine the accuracy of Mid Upper Arm Circumference (MUAC) compared to BMI.

Method: We recruited 920 children aged 5–18 years from primary and secondary schools in Yenagoa in the Niger Delta region of Nigeria using a multistage random sampling technique. Weight, height and MUAC of the children were measured using standard methods. We calculated BMI, defined obesity as BMI-for-age z- scores >2 and the corresponding cut-off values of MUAC for defining obesity were determined. Sensitivity, specificity, negative predictive values (NPV) and positive predictive values (PPV) of MUAC were determined using BMI as the gold standard. Area under the ROC (AUC) was also determined to assess MUAC’s ability to correctly identify obesity.

Results: MUAC correlated positively with BMI and age, the cut-off values increased with age in both boys and girls. When compared with BMI, using sex and age group specific cut-off for MUAC, the estimated specificities were relatively higher than sensitivities in all age groups. However, the best performance of MUAC for detection of obesity was recorded for girls (AUC = 0.94, 96% CI = 0.89, 0.99) and boys (AUC = 0.89, 95% CI = 0.78, 0.99) in age group 10-14 years. Similarly, the NPV were higher than the PPV.

Conclusion: The MUAC showed remarkably high accuracy for diagnostic and screening use among children aged 10-14 years but inconsistent results in other age groups.