OP0208 INCIDENT GOUT: RISK OF DEATH AND CAUSE-SPECIFIC MORTALITY IN WESTERN SWEDEN – A NESTED CASE CONTROL STUDY

Abstract

Background:Excess mortality in gout has been attributed to it’s positive association with many comorbidities. Lately, a negative association with dementia has been suggested in some cohort studies. Data is limited on how this reflects in cause-specific mortality of gout patients.Objectives:Our aims were to determine the relative risks in incident gout patients compared to general population 1) for overall death 2) for cause-specific mortality.Methods:All incident cases of gout (definition: 1≥ ICD-10 code for gout (M10/M14.0) in the population based health care database VEGA; no gout diagnosis ≥5 years previously) between 2006-2015 in western Sweden were identified. Five population controls per case matched on age, sex and place of residence were identified. Comorbidities, defined by ICD-10 codes, (alcohol related disorders, hypertension, ischemic heart disease, heart failure, cerebrovascular disease, diabetes, dyslipidemia, obesity, renal disease, dementia, lung diseases and cancer) were identified for 5 years preceding index date for cases and controls in VEGA. Patients were followed until the earliest of death, migration or study end 31 of December 2017. Cause of death was identified through the national cause of death register and grouped as death due to: CVD, renal disease, dementia, infections, diabetes, diseases of the digestive system, lung diseases, cancer and other. COX regression analyses, adjusted for baseline demographics and comorbidities, were used to compare mortality in cases and controls, taking competing cause of death into account by the Fine and Gray method.Results:From the total adult population of western Sweden between 2006 and 2015 (yearly average of 1264150 individuals), we identified 24320 cases of incident gout and 119781 controls, who were followed on average 5.3 and 5.6 years respectively. At baseline mean age was (SD) 67.3 years (15.3) and 67.6% were men. At baseline, income and level of education was significantly lower in gout cases compared to controls, whereas all comorbidities were significantly more common among gout cases (data not shown) except for dementia which was significantly more common in controls, 4.2% versus 2.5% in cases, p<.0001. The HR for overall death was increased in gout patients (HR: 1.08 (95% CL: 1.05-1.11) (Table 1). Gout cases had significantly increased risk for death by CVD, renal disease, infections, diseases of the digestive system and significantly decreased risk for death by dementia and cancer (Table 1). Point estimates were similar in men and women (data not shown).Table 1.Causes of death by exposure status and cause-specific mortality overall, gout cases compared to controls, adjusted hazard ratios by the Fine and Gray method, 95% confidence intervalsCauses of deathCause of death, n (%)Hazard ratios (95% CI)Gout cases, n = 24320Controls, n= 119781Model 1Model 2Cardiovascular disease3527 (14.5)11369 (9.5)1.61 (1.55-1.67)1.20 (1.16-1.26)Renal disease140 (0.6)239 (0.2)2.79 (2.26-3.44)1.68 (1.31-2.16)Dementia287 (1.2)2922 (2.4)0.45 (0.40-0.51)0.68 (0.60-0.77)Infections437 (1.8)1631 (1.4)1.27 (1.14-1.41)1.15 (1.03-1.28)Diabetes250 (1.0)665 (0.6)1.80 (1.55-2.08)1.02 (0.87-1.20)Diseases digestive system226 (0.9)725 (0.6)1.49 (1.29-1.74)1.36 (1.16-1.59)Lung diseases306 (1.3)1216 (1.0)1.20 (1.06-1.36)0.89 (0.78-1.01)Cancer1179 (4.9)6067 (5.1)0.92 (0.87-0.98)0.94 (0.88-0.99)Other655 (2.7)2899 (2.4)1.08 (0.99-1.17)1.09 (0.99-1.19)All-cause mortality7007 (28.8)27733 (23.2)1.32 (1.29-1.36)1.08 (1.05-1.11)Model 1: adjusted for age and sexModel 2: adjusted for baseline values for: age, sex, marital status, income, education, born outside of Sweden, alcohol related disorders, hypertension, ischemic heart disease, heart failure, cerebrovascular disease, diabetes, dyslipidemia, obesity, renal disease, dementia, lung diseases and cancerConclusion:This study demonstrates a modest increase in overall mortality in gout patients and a decreased risk of death from dementia reflecting it’s inverse relation to gout.Disclosure of Interests:None declared