Improving nutritional assessment in pediatric anorexia nervosa: Clinical value of key serum biomarkers

Reliable biochemical markers of starvation are needed to improve detection and monitoring of starvation in pediatric anorexia nervosa (AN), thus we explored new and revisited old potential serum biochemical markers.

In this prospective cohort study we included 65 pediatric patients with AN. Clinical data and serum at diagnosis were collected. Measured analytes included calcium, inorganic phosphate, alkaline phosphatase, albumin, transferrin, ceruloplasmin, prealbumin, C3 and C4 complement, ferritin, and vitamin D. Groups were compared by phenotype (classical AN vs. atypical anorexia nervosa [AAN]) and by severity of starvation (body mass index z-score: severe Z ≤ -2.0 vs. mild-moderate Z > -2.0) using the Mann-Whitney test. Receiver operating characteristic (ROC) analysis assessed discriminatory performance. Moreover, sensitivity, specificity, positive predictive value, and negative predictive value were calculated.

Median age was 15 years, 63 participants were female. Median symptom duration was 6 months and median weight loss 19.8% (z-score -2.03 ± 1.40). Compared with classical AN, AAN patients had higher transferrin and C3 (p = 0.019 and p = 0.009). Severe malnutrition (Z ≤ -2.0) was associated with higher ferritin (p = 0.013) and lower transferrin, ceruloplasmin, and C3 (p = 0.004, p = 0.004, and p < 0.001). ROC area under the curves were: C3 0.75 (95% confidence interval 0.63-0.87), transferrin 0.71, ceruloplasmin 0.70, and ferritin 0.68. Specificity was high (71%-97%) and negative predictive values excellent (98%-99%).

Transferrin, ceruloplasmin, complement C3 and ferritin reflect complementary aspects of starvation in pediatric AN. Complement C3 showed the best discriminatory performance for severe malnutrition. Prealbumin did not correlate with phenotype or severity. These markers could help in early identification and monitoring of severe malnutrition.