Prevalence of different metabolic phenotypes of obesity in Iranian children and adolescents: the CASPIAN V study.

Background: Pediatric metabolic disorders are a major health problem. The prevalence of child and adolescent metabolic disorders particularly obesity has globally shown a growing pattern. The aims of this study were to estimate the prevalence of different metabolic phenotypes of obesity in children and adolescents.

Methods: This multi-centric cross-sectional study was conducted in 2015 in 30 provinces of Iran. Participants consisted of 4200 school students aged 7-18 years, studied in a national school-based surveillance program (CASPIAN- V) in Iran. Metabolic syndrome (MetS) and obesity was defined according to ATP III and WHO criteria respectively. Subjects were classified into four different metabolic phenotypes of obesity; metabolically healthy nonobese (MHNO), metabolically healthy obese (MHO), metabolically non-healthy non-obese (MNHNO) and metabolically non-healthy obese (MNHO). Moreover students were classified in four different phenotypes of obesity; normal; only abdominal obesity (AO), only generalized obesity (GO) and combined obesity (CO).

Results: The prevalence (95% confidence interval) of different metabolic phenotypes of obesity, MHO 10.35 (9.1, 11.8), MNHNO 3.31 (2.6, 4.2) and MNHO 2.19 (1.6, 2.9) was found in boys, while the prevalence of these phenotypes was significantly lower in girls (7.74 (6.6, 9.1), 3.11 (2.4,5.1) and 1.41 (0.9,2.1) respectively). The prevalence of only AO, only GO and CO was 12.17% (11.6, 12.7), 2.51% (2.3,2.8), and 8.86% (8.4,9.3), respectively. Based on gender differences, the prevalence of AO was significantly higher among girls than boys (12.4% of girls vs. 11.9% of boys).

Conclusions: Healthy lifestyle education and program interventions are necessary for children with different metabolic phenotypes of obesity, as there is a high probability that they may suffer from poor health in the future.