beta-carotene and Hyperuricemia

Our objective was to examine the cross-sectional associations between concentrations of vitamin A and beta-carotene, a major source of vitamin A, with concentrations of uric acid in a nationally representative sample of adults from the United States. We conducted a cross-sectional study using data from up to 10893 participants aged ≥ 20 years of National Health and Nutrition Examination Survey from 2001 to 2006. Concentrations of uric acid adjusted for numerous covariates increased from 305.8 μmol/L in the lowest quintile of vitamin A to 335.3 μmol/L in the highest quintile (p for linear trend <0.001). The prevalence ratio for hyperuricemia also increased progressively across quintiles of serum vitamin A reaching 1.82 (95% confidence interval [CI]: 1.52, 2.16; p for linear trend <0.001) in the top quintile in the maximally adjusted model. Adjusted mean concentrations of uric acid decreased progressively from quintile 1 (333.8 μmol/L) through quintile 4 of concentrations of beta-carotene and were similar for quintiles 4 (313.5 μmol/L) and 5 (313.8 μmol/L). Concentrations of beta-carotene were inversely associated with hyperuricemia (adjusted prevalence ratio comparing highest with lowest quintile = 0.61; 95% CI: 0.52, 0.72; p for linear trend <0.001). Concentrations of uric acid were significantly and positively associated with concentrations of vitamin A and inversely with concentrations of beta-carotene. These cross-sectional findings require confirmation with experimental studies of vitamin A and beta-carotene supplementation.

Topics: Adult; beta Carotene; Cross-Sectional Studies; Dietary Supplements; Female; Humans; Hyperuricemia; Male; Middle Aged; Nutrition Surveys; Prevalence; United States; Uric Acid; Vitamin A

Uses of synthetic vitamin A derivatives (e.g., isotretinoin used for severe acne) and high doses of preformed vitamin A have been implicated in the pathogenesis of hyperuricemia and gout, whereas a trial reported that β-carotene may lower serum uric acid (UA) levels. We evaluated the potential population impact of these factors on serum UA in a nationally representative sample of US adults.. Using data from 14,349 participants ages ≥20 years in the Third National Health and Nutrition Examination Survey (1988-1994), we examined the relationship between serum retinol, β-carotene, and UA levels using weighted linear regression. Additionally, we examined the relationship with hyperuricemia using weighted logistic regression.. Serum UA levels increased linearly with increasing serum retinol levels, whereas serum UA levels decreased with increasing serum β-carotene levels. After adjusting for age, sex, dietary factors, and other potential confounders, the serum UA level differences from the bottom (referent) to the top quintiles of serum retinol levels were 0, 0.16, 0.32, 0.43, and 0.71 mg/dl (P for trend <0.001), and for β-carotene were 0, -0.15, -0.29, -0.27, and -0.40 mg/dl (P for trend <0.001), respectively. Similarly, the multivariate odds ratios of hyperuricemia from the bottom (referent) to top quintiles of serum retinol levels were 1.00, 1.30, 1.83, 2.09, and 3.22 (P for trend <0.001) and for β-carotene were 1.00, 0.85, 0.68, 0.73, and 0.54 (P for trend <0.001), respectively. The graded associations persisted across subgroups according to cross-classification by both serum retinol and β-carotene levels.. These nationally representative data raise concerns that vitamin A supplementation and food fortification may contribute to the high frequency of hyperuricemia in the US population, whereas β-carotene intake may be beneficial against hyperuricemia. The use of β-carotene as a novel preventive treatment for gout deserves further investigation.

Topics: Adult; Aged; Aged, 80 and over; beta Carotene; Female; Humans; Hyperuricemia; Male; Middle Aged; Nutrition Surveys; Uric Acid; Vitamin A