Gout in Older Adults: The Atherosclerosis Risk in Communities Study

Abstract

Background: It is unclear whether traditional and genetic risk factors in middle age predict the onset of gout in older age.

Methods: We studied the incidence of gout in older adults using the Atherosclerosis Risk in Communities study, a prospective U.S. population-based cohort of middle-aged adults enrolled between 1987 and 1989 with ongoing follow-up. A genetic urate score was formed from common urate-associated single nucleotide polymorphisms for eight genes. The adjusted hazard ratio and 95% confidence interval of incident gout by traditional and genetic risk factors in middle age were estimated using a Cox proportional hazards model.

Results: The cumulative incidence from middle age to age 65 was 8.6% in men and 2.5% in women; by age 75 the cumulative incidence was 11.8% and 5.0%. In middle age, increased adiposity, beer intake, protein intake, smoking status, hypertension, diuretic use, and kidney function (but not sex) were associated with an increased gout risk in older age. In addition, a 100 µmol/L increase in genetic urate score was associated with a 3.29-fold (95% confidence interval: 1.63-6.63) increased gout risk in older age.

Conclusions: These findings suggest that traditional and genetic risk factors in middle age may be useful for identifying those at risk of gout in older age.

Keywords: Gout; Urate genetics.

Figure 1.

Prevalence gout (A) and incidence of gout (B). The prevalence of gout (% of participants with a history of gout) across the age spectrum for participants of Atherosclerosis Risk in Communities was estimated using a Kaplan–Meier approach. All cumulative incidences (%) from visit 1 should be interpreted as the percentage of participants with newly diagnosed gout, conditioned on survival to that age.

Figure 2.

Cumulative incidence of gout by (A) quartile of genetic urate score stratified by sex (B and C). The cumulative incidence of gout from visit 1 for participants of Atherosclerosis Risk in Communities was estimated using a Kaplan–Meier approach. All cumulative incidences (%) from visit 1 should be interpreted as the percentage of participants with newly diagnosed gout, conditioned on survival to that age. The genetic urate score is measured in μmol/L. Quartile 1 of the genetic urate score ranges from −59.1 to −13.1; quartile 2: −13.2 to 0.3; quartile 3: 0.4 to 12.0; quartile 4: 12.1 to 60.8.