Background/Purpose: Increased levels of serum urate (sUA) have been reported in association with hypertension, chronic kidney disease, and obesity. All these conditions are over-represented in US African Americans, who also have greater environmental risk factors for developing hyperuricemia including elevated fructose intake.  Our group has previously reported that young African Americans have lower sUA concentrations than Caucasians after adjustment for clinical and demographic factors. Objectives: To determine whether there is a differential association between sUA and race in young adults.

Methods:  We examined baseline data on consecutively enrolled individuals (age 18 – 40 years) in an interventional study aimed at lowering blood pressure (BP) through the administration of a urate-lowering therapy. African Americans were over-represented in the sample by study design. Enrollment criteria included a sUA of ≥ 5.0 mg/dL for men or ≥ 4.0 mg/dL for women. After sUA means comparisons between African Americans and other races using t-test, we performed multivariable adjustments for age, sex, serum creatinine, and body mass index (BMI) in a multiple linear regression model.

Results: Sixty-nine participants recruited from Birmingham, AL were included in the analysis. Participants had a mean age (±standard deviation) of 29.0 ± 6.9 years, 30% were female, 43% were African Americans (AAs), and the mean BMI was 29.0 ± 6.0 kg/m². The mean sUA was 5.9 ± 1.1 mg/dL (range: 3.9 to 8.5 mg/dL). We found a significantly lower sUA for African Americans compared to persons of other races (5.5 ± 1.2 mg/dL vs 6.3 ± 1.0 mg/dL, p= 0.009).  After multivariable analysis the difference in sUA between African Americans and other races was attenuated to non-significance (p= 0.33) due to the effects of BMI and sex.  As expected, the association between sUA and sex was significant (Table).

Conclusion:   In this cross-sectional analysis of young adults, African Americans had lower sUA concentrations than other races. However, in our model this difference is explained by the effect of sex differences in sUA and BMI. A potential limitation is that participants were enrolled after they met a sUA threshold so not all the ranges of sUA in a normal population are represented in this analysis.  Larger studies will be needed to fully address this question.  Table. Multivariable regression model on the association between serum urate and race among young adults (n=69)

^{BMI= Body-mass index}