Longitudinal Association Between Serum Uric Acid and Arterial Stiffness Results From the Baltimore Longitudinal Study of Aging

Serum uric acid (SUA) has long been associated with increased cardiovascular risk, with arterial stiffness proposed as a mediator. However, evidence on the association between SUA and arterial stiffness is limited to contradicting cross-sectional studies. In this analysis, we examined the longitudinal relationship between SUA and pulse wave velocity, a measure of arterial stiffness, in a community-dwelling population. We studied 446 women and 427 men participating in the BLSA (Baltimore Longitudinal Study of Aging), with 1409 and 1434 observations, respectively, over an average period of 6 years. At baseline, mean ages of women and men were 65 +/- 13 and 68 +/- 13 years; mean SUA, 4.6 +/- 1.1 and 5.7 +/- 1.3 mg/dL; mean pulse wave velocity, 8.1 +/- 1.7 and 8.6 +/- 1.9 m/s, respectively (P<0.0001). In gender-stratified models accounting for age, blood pressure, renal function, metabolic measures, and medications, there was a significant interaction between SUA and follow-up time in men (beta=0.69; P=0.0002) but not in women. Men, but not women, in the highest gender-specific SUA tertile at baseline (SUA >= 6.2 mg/dL in men and SUA >= 4.9 mg/dL in women) had a greater rate of pulse wave velocity increase over time than those in the lowest tertiles (beta=0.997; P=0.012). This gender difference was lost when the distribution of SUA in men and women was made comparable by excluding hyperuricemic men (SUA >= 6.2 mg/dL). In conclusion, higher SUA was associated with greater increase in pulse wave velocity in men but not women; this association was lost when men with SUA >= 6.2 mg/dL were not included, suggesting a threshold for SUA association with arterial stiffness, which is more frequently reached in men. Online Data Supplement