The neutrophil to lymphocyte ratio (NLR) positively correlates with the presence and severity of metabolic syndrome in obese adults, but not in obese children/adolescents

Abstract

Metabolic syndrome (MetS) associated with obesity is a pathological condition increasing worldwide. Recent studies have demonstrated that the neutrophil to lymphocyte ratio (NLR) can be successfully used to stage MetS in obese adults. The aim of the study was to evaluate NLR values in 552 children/adolescents (M 219, F 333; 14.8 [12.9-16.3] years) and 231 adults (M 88, F 143; 52.3 [36.4-63.3] years) with morbid obesity, subdivided into subgroups according with the presence or absence of MetS. Adult patients with obesity showed a higher prevalence of MetS compared to the pediatric population (71% vs 26%), associated with a greater number of subjects with 3 and 4-5 altered components for MetS. NLR was higher (P-value = 0.041) in adults with MetS compared with those without. NLR values also positively correlated with the severity grade of the syndrome (P-value = 0.032). By contrast, in pediatric subjects with obesity with MetS, NLR values were comparable with those recorded in subjects without MetS (P-value = 0.861), no correlation being found with MetS severity (P-value = 0.441). Our study confirms the importance of NLR as an inflammatory indicator associated with MetS in adult subjects with severe obesity, while it excludes a similar role in children/adolescents.

Keywords: Adults; Children/adolescents; Metabolic syndrome; Neutrophil to lymphocyte ratio; Obesity.

Fig.1

NLR increases in MetS+ obese adults compared with MetS+ obese children/adolescents. Dot plots represent the NLR values in children/adolescents (red) and adults (black) both with metabolic syndrome. The NLR difference in the two populations was calculated using the non-parametric Mann–Whitney U test. **** = P-value < 0.0001

Fig. 2

Neutrophils/lymphocytes ratio (NLR) positively correlates with the severity of metabolic syndrome in adult patients. a,c Dot plots represent the NLR values in children/adolescents and adults according to the severity of metabolic syndrome. The severity of metabolic syndrome is indicated with the amount of IDF criteria: MetS 1–2 (low grade, no metabolic syndrome in red), MetS 3 (moderate grade, in black), MetS 4–5 (high grade in orange). P-value is calculated using the non parametric Mann–Whitney U test. * = P-value < 0.05; ns (not significant) = P-value > 0.05. b,d Non parametric Spearman rank correlation test between neutrophil-lymphocytes ratio and metabolic syndrome in children/adolescents and adults showed a positively correlation between the variables. Abbreviations: r = correlation coefficient. * = P-value < 0.05; ns (not significant) = P-value > 0.05

Fig. 3

Accuracy of NLR as a marker of metabolic syndrome in children/adolescents and adults. a ROC (receiver operating characteristic) curves for NLR in children/adolescents. AUC = 0.502, P-value = 0.862. b ROC (receiver operating characteristic) curves for NLR in children/adolescents. AUC = 0.5851, P-value = 0.041. Abbreviation: ROC, receiver operating characteristic curve; AUC, area under the curve