Relationship of sodium intake with obesity among Iranian children and adolescents.

Background: Emerging evidence suggests a relationship between sodium (Na) intake and obesity risk. The aim of this study was to investigate the link between 24-hour (24-h) urinary Na excretion and adiposity measures in a sample of Iranian children and adolescents.

Methods: This cross-sectional study was performed among 374 healthy individuals aged 11-18 years old. Random cluster sampling method was used to select the participants from 4 districts in Isfahan, Iran. Na excretion was estimated using a 24-h urinary sample. Creatinine (Cr) level was used to confirm the completeness of samples. Anthropometric measures including weight, height and waist circumference (WC) were obtained based on standard protocols.

Results: The odds ratio (OR) for overweight/obesity in subjects with the highest tertile of Na excretion compared with the lowest tertile was 8.01 [95% confidence interval (CI) 4.20-15.3] in crude model and 8.33 (95% CI 4.14-16.8) after adjusting for potential confounders. The association was independent of intake of energy and sugar-sweetened beverages (SSBs). The OR for abdominal obesity in the highest tertile of Na excretion compared with the lowest tertile was 9.12 (95% CI 4.78- 17.4) in crude model and 9.75 (95% CI 4.88-19.5) after controlling for potential confounders. The association was independent of energy intake or SSBs consumption.

Conclusion: Our study showed a positive association between Na excretion and obesity among children and adolescents. Further investigation through longitudinal studies using a more representative sample of children and adolescents is suggested to determine whether this is a causal relationship.