Objective: To assess the heritability of serum uric acid in adult, using the classic twin design.
Methods: Adult Twins were recruited from the Qingdao Twin Registry. Uric acid, height, weight were measured. Zygosity in all the same-sex twin pairs was determined by 16 polymorphic markers. Heritability was assessed by structural equation models, with age, gender and body mass index (BMI) included as covariates.
Results: In total, 687 twin pairs were available for data analyses, including 420 pairs of monozygotic and 267 pairs of dizygotic twins. After logarithm transformed, uric acid in males (17.47 +/- 1.91) was significantly higher than in females (15.22 +/- 1.70, P < 0.0001). After adjustment on age, sex and BMI, intraclass correlations for uric acid were 0.70 for monozygotic twins and 0.40 for dizygotic twins. The sex-limitation AE model, combining additive genetic and unique environmental factors, could produce the best fit for the data. Heritability estimate for uric acid was 70.5% (95%CI: 65.9 - 74.6), with the proportion of unique environmental effects as 29.5% (95%CI: 25.4 - 34.2).
Conclusion: Additive genetic effects appeared to be the major contributor to the variation of uric acid in this twins sample being studied.