Low-density Lipoprotein Subclasses are Associated with Serum Uric Acid Levels

Levels of uric acid (UA) and low-density lipoprotein (LDL) subclasses are both associated with coronary heart disease and metabolic syndrome (MetS). However, the relationship between UA and LDL subclasses is not well understood.Subjects included 633 Japanese subjects not receiving medication for hyperuricemia, diabetes mellitus, dyslipidemia, or chronic renal disease who underwent an annual health examination that included determination of small, dense low-density lipoprotein cholesterol (sdLDL-C) and malondialdehyde-modified low-density lipoprotein (MDA-LDL) levels.Serum UA exhibited a positive correlation with both sdLDL-C and MDA-LDL (r = 0.335 and 0.339, respectively). Since sdLDL-C and MDA-LDL show strong positive association, sdLDL-C and MDA-LDL were used as separate explanatory variables in multiple linear regression analysis. Male gender, waist circumference (WC), high-density lipoprotein cholesterol (HDL-C), logarithmic transformed triglyceride (TG) [ln(TG)], and MDALDL as a group were associated with serum UA. Similarly, male gender, body mass index (BMI), ln(TG), and sdLDL-C as a group were associated with serum UA. These results further supported that both MDA-LDL and sdLDL-C levels were positively correlated with serum UA levels. Evaluation of subjects' characteristics according to tertile UA values (tertile 1, < 5.0 mg/dL; tertile 2, 5.0 - < 6.3 mg/dL; tertile 3, ≥ 6.3 mg/dL) indicated that MDALDL and sdLDL-C levels gradually increased with increasing UA levels. Additionally, the upper third UA tertile was associated with the worst metabolic profile based on BMI, WC, blood pressure, fasting plasma glucose, fasting immunoreactive insulin, homeostasis model assessment insulin resistance, TG, HDL-C, and the number of MetS components.Both LDL particle size and oxidized LDL were associated with serum UA levels in Japanese subjects.