Etiology and pathogenesis of gout

SLEEP APNEA IN GOUT PATIENTS: UNDERLYING MECHANISMS AND SHARED PATIENT SUBTYPES

Acute and chronic inflammation in gout causes permanent tissue damage, leads to restricted mobility and significantly reduces the quality of life. Obstructive sleep apnea (OSA) is a breath disordered sleep disease, which is a risk factor for respiratory, cardiovascular and cerebrovascular complications, nephropathy and other diseases. The aim of this paper was to explore the underlying mechanisms and shared pathways, targets and biomarkers of sleep apnea and gout. aiming at providing clear evidence about whether OSAS patients have higher serum uric acid levels and more susceptible to gout. Materials and methods. We conducted this literature analysis on relevant studies, which were identified via electronic databases from inception to May 30, 2020. Study selection was conducted according to predesigned criteria, and two authors independently extracted data from included studies. Results. In the period from 2010 to 2020, 4 large-scale population-based studies were conducted to prove that OSA can affect the level of uric acid, resulting in increased incidence of gout in OSA patients. Only one big population-based study during 2010-2020 assessed the development of OSA against the background of gout. The data from these studies showed an undoubted relationship between the two diseases, but to date it is not completely known how much it is due to common risk factors and how interlinked the development mechanisms are. Conclusions. Relationship between OSA, gout, and pro-inflammatory/metabolic disorders is therefore complex; with some recent studies indicate different mechanisms may play a role in the development of OSA-gout combination. The inconsistency in results may indicate the presence of several patient profiles or subtypes with gout-OSA comorbidity: combined with metabolic syndrome (most common), combined with renal dysfunction without obesity, and others (dietary violations, genetic diseases, acidosis). This paper reviews the research progress on the relationship between the epidemiological characteristics of OSA and the incidence of gout, with the insight into pathogenetic mechanisms of comorbidity.

Demographic and clinical features of gout patients in Turkey: a multicenter study

Gout results from multifactor interactions between gender, age, genetic and environmental factors. Environmental factors underlying gout and precipitating factors triggering acute attacks might vary in different populations with different lifestyles. In this study, we aimed to collect data regarding the demographic and clinical features, comorbid factors, and precipitating factors associated with the initiation of acute attacks in gout patients in Turkey. A total of 312 patients were included in this study (mean age, 58.8 ± 13.8 years; female/male ratio, 55/257). The demographic features, alcohol intake, clinical and laboratory features, and comorbid conditions including obesity, diabetes mellitus, hyperlipidemia, hypertension, and coronary heart disease were noted in a standard questionnaire. Precipitating factors initiating acute attacks (if any) were also noted. The patients were divided into 4 groups according to the region of location as central Anatolian region, southeast Anatolian region, Aegean region, and Trakya region. Our results were compared according to the gender and the location of the patients. The mean age at the start of the symptoms was 10 years higher in women (60.4 ± 14.8 and 50.6 ± 13.5 years in women and men, respectively, p < 0.001).Obesity was present in 40.1 %, diabetes mellitus in 17.9 %, hyperlipidemia in 30.1 %, hypertension in 53.5 %, coronary artery disease in 17 %, and nephrolithiasis in 21.8 % of patients. Precipitating factors triggering gout flares were as follows: diet (high consumption of meat or fish) in 46.5 %, alcohol consumption in 15.7 %, diuretics in 8.3 %, diet or diuretics in 5.1 %, diet or alcohol in 4.5 %, diet or alcohol or diuretics in 1.6 %, others in 4.2 %, and none in 14.1 %. The presence of diabetes and diuretic use was more common among women. Use of diuretics is a more common trigger for gout flares among women. On the other hand, various comorbid conditions, such as obesity and hypertension, and triggers for gout flares may differ between patients living in different geographic regions. In summary, we reported the first data regarding clinical and demographic characteristics of gout in Turkey. The majority of our patients could describe at least one "trigger" that initiated gout flare. Both comorbid conditions and triggers of attack might differ between men and women, and in different geographic areas. Better knowledge of the modifiable risk factors can be useful for the management strategy to optimize long-term patient outcomes in local clinics.