Beyond the Surface: Validating the Anthropometric-Biochemical Link in Childhood Malnutrition in Sokoto State, Nigeria

Abstract

Anthropometric indicators such as stunting, wasting, and underweight are the primary tools for diagnosing childhood malnutrition in resource-limited settings. However, the extent to which these visible signs reflect underlying biochemical derangements remains inadequately characterized. This study aimed to examine the associations between anthropometric indicators of malnutrition and key nutritional biomarkers among under-five children in Sokoto State, Nigeria. A facility-based cross-sectional study was conducted among 150 mother-child pairs attending Primary Health Centers. Anthropometric measurements (weight, height/length, MUAC) were collected and used to classify children by nutritional status (stunting, wasting, underweight). Venous blood samples were analyzed for Prealbumin, C-Reactive Protein (CRP), Serum Retinol (Vitamin A), Hemoglobin, Serum Albumin, and Serum Zinc. Statistical analyses included independent t-tests, Pearson's correlation, chi-square tests for trend, and binary logistic regression. Children classified as malnourished by MUAC (<12.5 cm) had significantly worse biomarker profiles than their well-nourished counterparts (p < 0.001 for all biomarkers). A strong, dose-response relationship was observed: the prevalence of vitamin A deficiency increased from 72.3% in normal children to 95.1% in MAM and 100% in SAM; zinc deficiency from 38.3% to 78.7% to 95.2%; and anemia from 46.8% to 85.2% to 97.6%. MUAC showed the strongest correlations with biomarkers (r = 0.56-0.71, p < 0.01). Critically, 72.3% of anthropometrically "normal" children had vitamin A deficiency, and 38.3% had three or more concurrent deficiencies. Logistic regression revealed that children with SAM had 18-43 times higher odds of biochemical deficiencies compared to normal children. Anthropometric status is strongly associated with biochemical depletion, supporting the use of MUAC for identifying children at highest risk. However, the high burden of "hidden hunger" among anthropometrically normal children reveals a critical limitation of sole reliance on anthropometry. These findings argue for integrated assessment approaches and multi-micronutrient interventions to address the full spectrum of malnutrition, from visible wasting to invisible biochemical deficiencies.