Birthweight and serum uric acid in American adolescents.

Elevated serum uric acid is associated with hypertension and chronic kidney disease. We evaluated the relationship between birthweight and uric acid in a nationally representative sample of 5390 US adolescents aged 12-15 in the National Health and Nutrition Examination Survey from 1999 to 2012. There was an inverse association between birthweight and uric acid after adjustment for sex, age, race, obesity, and dietary sodium intake. Each 1 kg increase in birthweight was associated with decreased uric acid by 0.11 mg/dL (95% CI: -0.16 to -0.06; model R2  = 0.32). This relationship was stronger in adolescents with elevated blood pressure (β = -0.25; 95% CI: -0.44 to -0.06; R2  = 0.50) but persisted in adolescents with normal blood pressure (β = -0.10; 95% CI: -0.15 to -0.05; R2  = 0.31). In conclusion, lower birthweight is associated with higher uric acid in US adolescents. These findings may support the hypothesis that reduced nephron number is associated with elevated uric acid.