The aim of the present study was to describe prevalence and trends in the incidence of gout and patterns of urate-lowering treatment (ULT) in the Western Swedish Health Care Region (WSHCR) from 2002 to 2012. We used regional and national healthcare registers to estimate the prevalence and incidence of gout in 2012, and trends in incidence for each calendar year from 2005 to 2012. We also investigated the pattern of ULT for gout using the Swedish Prescribed Drug Register. In 2012, in the population aged 20 years and above, the prevalence of gout was 1.8 % (95 % confidence interval (CI) 1.77 to 1.82) and the incidence was 190 cases (95 % CI 180 to 200) per 100,000 person-years. Applying more strict definitions for a gout case rendered a prevalence of 1.36 % (95 % CI 1.34 to 1.38) and 0.5 (95 % CI 0.49 to 0.51) per 100,000 person-years, respectively. The incidence of gout increased steadily and significantly from 2005 to 2012, with an almost 50 % increase in the total population. There was no significant difference in the prevalence of gout in rural compared to urban areas. ULT was dispensed to only 42 % of patients with gout in 2012 who had ever been diagnosed with gout during the preceding 10-year period. Gout is the most common arthritic disease in WSHCR, Sweden, and has increased substantially over the last decade, with only a minority of prevalent cases in 2012 receiving ULT.

The aim of this study is to examine the occurrence of comorbidities at the time of first diagnosis of gout compared with matched population controls, overall and by sex, as well as to examine the crude and age-standardized prevalence of these comorbidities in men and women with gout at first diagnosis. A population-based study used data from Swedish national and regional registers, including 14,113 gout patients aged ≥ 20 years, with a first recorded diagnosis of gout between 1 January 2006 and 31 December 2012, and 65,782 population controls, matched by age, sex and county. Prevalence ratios (95% confidence intervals) comparing gout cases and controls were calculated, overall and by sex. Crude and age-standardized prevalence (95% confidence interval) of all comorbidities in gout patients were calculated, to show differences between sexes, taking also the higher age at diagnosis in women into account. All examined comorbidities were 1.2–2.5-fold more common in gout patients at diagnosis than in population controls in both sexes. Women with gout were on average 6 years older than men at first gout diagnosis and most comorbidities, including obesity and diuretic use, were or tended to be more frequent in women than in men. When standardizing for age, women had a higher prevalence of thromboembolism (6.6% vs 5.2%) and chronic obstructive pulmonary disease (3.1% vs 2.4%). Men, on the other hand, had a higher prevalence of coronary heart disease (9.4% vs 6.4%), atrial fibrillation (9.0% vs 6.0%), congestive heart failure (7.7% vs 6.6%) and stroke (4.1% vs 3.3%). The occurrence of most comorbidities was significantly increased at first diagnosis of gout in both sexes. Women were older at diagnosis and had higher occurrence of most comorbidities, including obesity and diuretic use, factors that increase serum urate, and this needs to be taken into account when starting and optimizing urate lowering therapy. These sex differences were attenuated when standardizing for age and the occurrence of cardiovascular diseases was actually higher in men.

Background: Hyperuricemia is closely associated with cardiovascular disease (CVD). However, it has not been definitively established whether this association is independent of traditional cardiovascular risk factors (CVRFs) and whether it is gender-dependent. The aim of this study was to investigate in a population-based cohort (age range, 50–64 years) stratified by sex the association between the serum urate (SU) concentration and subclinical atherosclerosis, as reflected in the coronary artery calcification (CAC) score, common carotid intima-media thickness (CIMT), and carotid plaque score. Methods: The study involved participants in the Swedish CArdioPulmonary bioImage Study (SCAPIS) Pilot cohort (N = 1040; 48.8% males). This pilot cohort is part of the large population-based SCAPIS with 30,000 participants in the age range of 50–64 years, aimed at improving risk prediction for CVD. Subjects with a self-reported previous history of CVD (N = 68) or gout (N = 3) were excluded. The CAC score was assessed with the Agatston method using computed tomography. CIMT and carotid plaques were quantified by ultrasound. The associations between the SU quartiles and different levels of CAC, CIMT, and carotid plaques were assessed by multivariable logistic regression. Results: Age, BMI, education level, smoking, physical activity, hs-CRP, hypertension, and dyslipidemia showed no differences between males and females, while CAC (score > 0) and diabetes were both twice as common in men than in women (58% vs 26% and 8% vs 4%, respectively). Higher SU quartiles were in both sexes associated with BMI, hs-CRP, and the prevalence of hypertension, and in women, they were also associated with the prevalence of dyslipidemia. The three upper quartiles of SU (>308μmol/L) were linked to higher CAC scores in men, when adjusting for CVRFs, but not in women. CIMT and carotid plaques showed no correlation to SU in either sex. Conclusions: Higher levels of SU are associated with the presence of CAC in men but not in women, whereas SU is not associated with CIMT or carotid plaques in either men or women. This implies that the biological effects of SU differ in men and women or that SU has varying effects on different vascular beds or during the different stages of the atherosclerotic process.

Nephrolithiasis (NL) is known to be associated with gout, although there are few comparative studies on risk and risk factors for NL in gout compared to population cohorts. In this cohort study we investigated: (1) overall incidence of NL in gout (cases) and general population controls; (2) risk and risk factors (common comorbidities and medications) for first-time NL in cases and controls separately. Cases (n = 29,968) and age-matched and sex-matched controls (n = 138,678) were identified from the regional healthcare database in western Sweden (VEGA). The analyzed risk factors (comorbidities and current medication use) for first-time NL, and socioeconomic factors were retrieved from VEGA and other national Swedish registers. For cases, follow up began on 1 January 2006 or on the first diagnosis of gout if this occurred later, and for controls on their index patient’s first diagnosis of gout. Follow up ended on death, emigration or 31 December 2012. Incidence rates (IR) per 1000 person-years and hazard ratios (HR) were calculated. The incidence calculations were performed for cases (regardless of prior NL) and their controls. HRs with first occurrence of NL as outcome were calculated only in those without previous NL. In cases there were 678 NL events (IR: 6.16 events per 1000 person-years (95% CI: 5.70–6.64) and in controls 2125 NL events (IR 3.85 events per 1000 person-years (95% CI: 3.69–4.02), resulting in an age-sex-adjusted incidence rate ratio of 1.60 (95% CI:1.47–1.74). Point estimates for predictive factors were similar in cases and controls, except for a significant interaction for losartan which increased the risk of NL only in controls (HR = 1.49 (95% CI: 1.03–2.14). Loop diuretics significantly decreased the risk of NL by 30–34% in both cases and controls. Further significant predictors of NL in gout cases were male sex, diabetes and obesity and in controls male sex and kidney disease. The risk (age and sex adjusted) of NL was increased by 60% in cases compared to controls. None of the commonly used medications increased the risk of NL in gout patients.

Population-based databases in Nordic countries offer unique opportunities for large-scale population-based epidemiological studies. The personal identity number enables researchers to link different registers at the individual level, which can be used for large-scale epidemiological population-based studies. This review outlines how these opportunities have been used so far in the field of gout research, as well as the potential challenges and limitations. Their major advantage is that they cover the entire population, minimizing problems such as selection bias and loss to follow-up. This has enabled us to provide information on gout regarding risk factors; occurrence; association with comorbidities in relation to gout onset; treatment patterns; as well as its effect on other outcomes, such as sick leave and mortality. Validity issues, missing data, and legal issues are some of the challenges that researchers need to deal with. Choosing the most appropriate combination of databases to use for a specific question is crucial in order to maximize validity and adjust for confounders. Despite challenges and potential limitations, the Swedish registers have provided valuable epidemiological results and will continue to play an important role in the years to come.

Objectives To investigate the impact of allopurinol use on the risk of first-ever acute coronary syndrome (ACS) event in patients with gout. Methods Using national and regional register data, we included all patients with a gout diagnosis at primary or specialised care in Western Sweden in the period 2007–2017 (n=18 862; 67% male patients). Patients with a prior history of coronary heart disease (CHD) were excluded. Follow-up started at the first gout diagnosis and ended at the first-ever ACS event, death or study end. The main outcome was the risk of first-ever ACS in: (1) allopurinol users versus non-users, by defining three categories of allopurinol exposure: exposed to 100 mg, >100 mg and no exposure (reference) and (2) allopurinol initiators (within 125 days) versus long-term users (reference). Multivariable logistic regression analysis was used to calculate ORs and 95% CIs. Results In analysis 1 (n=18 862), 15.3% (n=2892) were exposed to 100 mg, 9.1% (n=1717) to >100 mg and 75.6% (n=14 253) were not exposed. Allopurinol users were older and had more comorbidities compared with non-users. Allopurinol exposure (100 mg and >100 mg) was associated with significantly lower odds of first-ever ACS (OR 0.77; 95% CI 0.63 to 0.94, and OR 0.61; 95% CI 0.47 to 0.81, respectively). In Analysis 2, allopurinol initiators (n=489) had significantly higher odds of first-ever ACS compared with long-term users (n=2916) (OR 1.68; 95% CI 1.03 to 2.75). Conclusions In patients with gout and without CHD, long-term allopurinol use protects against first-ever ACS compared with non-users. In contrast, allopurinol initiators, possibly having more systemic inflammation, had a higher risk of first-ever ACS compared with long-term users.