Waist-to-height ratio cut-off points to predict obesity in adolescents and associa-tion with inflammatory markers.

Introduction: obesity increases inflammatory molecules and cardiovascular risk even in young populations. New indicators are being investigated, including the waist-to-height ratio (WHtR) to predict obesity and the relationship with inflammatory markers in childhood and adolescence. Objective: to identify the cut-off points of the WHtR to determine obesity and its association with inflammatory markers in adolescents in São Luís, state of Maranhão, Brazil. Methods: this is a cross-sectional study, with 2,209 adolescents aged 18 and 19, belonging to the third phase of the birth cohort entitled "RPS", carried out in 2016. The total area under the ROC curve (AUC) was identified to assess the predictive capacity of WHtR in relation to body fat percentage (%BF), obtained by air displacement plethysmography (ADP). The association of WHtR with inflammatory markers interleukin-6 (IL-6), tumor necrosis factor (TNF-α) and c-reactive protein (CRP) was evaluated. Results: prevalence of obesity by the %BF was 10.3 % in males and 40.4 % in females. The cut-off points for the WHtR were 0.50 for females and 0.51 for males, with an AUC of 0.90 (95 % CI: 0.88-0.92) and 0.93 (95 % CI: 0.90-0.97). There was an association of elevated WHtR with higher levels of IL-6 and CRP (p < 0.05). Conclusion: the predictive capacity of WHtR for obesity was excellent. Elevated values of the WHtR were associated with early inflammatory markers. This study contributed to the identification of cut-off points for simple and low-cost anthropometric indicators.