Patients with gout, particularly women, have increased risk for vascular disease, according to findings of a study published online August 27 in the Annals of Rheumatic Diseases.
“Hyperuricaemia, the biochemical precursor to gout, has been linked with an increased incidence of, and mortality from, both [coronary heart disease (CHD)] and stroke,” write Lorna E. Clarson, MBChB, from the Research Institute for Primary Care & Health Sciences at Keele University in the United Kingdom, and colleagues. “Although gout is traditionally thought of as an intermittent inflammatory condition, recent ultrasound studies have identified persistent subclinical inflammation in the intercritical period between acute attacks. It has been hypothesised that the combination of persistent inflammation and hyperuricaemia may potentiate or synergise CHD development.”
Dr. Clarson and colleagues examined the association of gout with incident CHD, cerebrovascular disease (CVD), and peripheral vascular disease (PVD) in a large cohort of primary care patients with gout.
They identified 8386 patients with gout who were enrolled in the Clinical Practice Research Datalink and matched them on the basis of age, sex, and registered general practice, with 39,766 control participants. All patients and matched participants were older than 50 years and had no previous vascular history. Multivariable Cox regression allowed estimation of hazard ratios (HRs) in the 10 years after incidence of gout or matched index date (baseline), using covariates of sex, baseline age, body mass index, smoking, alcohol drinking, Charlson comorbidity index, history of hypertension, hyperlipidemia, chronic kidney disease, statin use, and aspirin use.
Men with gout had a small but significantly elevated risk for any vascular event (hazard ratio [HR], 1.06; 95% confidence interval [CI], 1.01 – 1.12) compared with men without gout. Similarly, men with gout had a greater risk for any CHD (HR, 1.08; 95% CI, 1.01 – 1.15) and PVD (HR, 1.18; 95% CI, 1.01 – 1.38).
Among women with gout, the risk for any vascular event was 25% higher than among women without gout (HR, 1.25; 95% CI, 1.15 – 1.35). Their risk for any CHD (HR, 1.25; 95% CI, 1.12 – 1.39) and PVD (1.89; 95% CI, 1.50 – 2.38) was also higher, but the researchers found no difference for risk for any CVD.
In addition, women with gout, but not men with gout, were at increased risk for angina, transient ischemic attack, and stroke.
“In this cohort of over 50s with gout, female patients with gout were at greatest risk of incident vascular events, even after adjustment for vascular risk factors, despite a higher prevalence of both gout and vascular disease in men,” the study authors write.
Limitations of this study include possible misclassification bias from the use of diagnostic codes, possible residual confounding, and inability to adjust for hyperuricemia.
“Further work is required to establish the effect of optimum management of both vascular risk factors and gout itself on the long-term health of gout patients, clarify the nature of the relationship between gout and PVD, and the mechanism by which women are at greatest risk,” the study authors conclude.
The National School for Primary Care Research funded this study. The senior author is funded by an Arthritis Research UK Clinician Scientist Award. The other authors have disclosed no relevant financial relationships.
Ann Rheum Dis. Published online August 27, 2014. Full text