Hyperuricemia is an emerging potential biomarker for metabolic syndrome (MetS) and its complications. This study aimed to investigate the risk factors of hyperuricemia, particularly, the association of hyperuricemia with MetS and general obesity according to sex. We performed multivariate logistic regression analyses using the 2016 Korean National Health and Nutrition Examination Survey data. Hyperuricemia was defined by a serum uric acid level ≥7.0 mg/dL for men and ≥6.0 mg/dL for women. General obesity was based on a body mass index (BMI) ≥25 kg/m². Among a total of 5591 Korean adult participants, 685 (12.3%) individuals had hyperuricemia. Hyperuricemia was significantly associated with MetS in men (odds ratio (OR): 2.38, 95% CI: 1.84–3.08) and in women (OR: 4.15, 95% CI: 2.75–6.28) after adjustments. General obesity was also independently related to hyperuricemia in both sexes (OR: 2.17, 95% CI: 1.76–2.68 in men, OR: 3.80, 95% CI: 2.82–5.12 in women). In subgroup analyses, the presence of concomitant MetS and general obesity posed a strikingly higher risk for hyperuricemia among women (OR: 7.24, 95% CI: 4.56–11.50) when compared to men (OR: 2.90, 95% CI: 2.12–3.96). More attention should be paid to the increased risk of hyperuricemia for females with both MetS and general obesity.

Ankylosing spondylitis (AS) is a male-predominant disease, and radiographic evidence of damage is also more severe in males. Estrogen modulates immune-related processes such as T cell differentiation and cytokine production. This study aimed to evaluate the effect of estrogen on the disease activity of spondyloarthritis (SpA). The effects of estrogen on the development of arthritis were evaluated by performing ovariectomy and 17β-estradiol (E2) pellet implantation in zymosan-treated SKG mice. Clinical arthritis scores were measured, and ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) small-animal positron emission tomography/computed tomography performed to quantify joint inflammation. The expression of inflammatory cytokines in joint tissue was measured. E2-treated mice showed remarkable suppression of arthritis clinically and little infiltration of inflammatory cells in the Achilles tendon and intervertebral disc. ¹⁸F-FDG uptake was significantly lower in E2-treated mice than in sham-operated (sham) and ovariectomized mice. Expression of TNF, interferon-γ, and IL-17A was significantly reduced in E2-treated mice, whereas expression of sclerostin and Dickkopf-1 was increased in E2-treated mice compared with sham and ovariectomized mice. Estrogen suppressed arthritis development in SKG mice, a model of SpA. Results of this study suggest that estrogen has an anti-inflammatory effect on the spondyloarthritis manifestations of the SKG arthritis model.

Hyperuricemia (HUA) has become a significant medical concern due to its complications and links to metabolic syndrome (MetS) and cardiovascular disease (CVD), which result in increased mortality. The pathogenic processes associated with unhealthy behaviors, MetS, and HUA can be cooperative and potentially synergistic in the activation of risk factors. Recent research has shown sex-based differences in the relationship between HUA and its associated risk factors. This study aimed to investigate these differences, particularly in the context of MetS and CVD risk factors and unhealthy lifestyles. We also aimed to evaluate the joint effects of these factors based on sex. We conducted a cross-sectional study using nationally representative survey data from the Korean National Health and Nutritional Examination Survey 2016–2018. We performed multivariable logistic regression analysis, calculating adjusted odds ratios (ORs) with their 95% confidence intervals (CIs). We also conducted subgroup analyses based on sex and the presence of MetS with or without unhealthy lifestyle factors (tobacco use, alcohol intake). We found sex-based differences in the relationships between HUA and MetS, CVD risk factors, and lifestyle behaviors. Our major finding was a significant association between MetS and HUA in both men and women, regardless of alcohol consumption and smoking status, and this association was stronger in women. We also observed a synergistic effect of MetS and lifestyle factors on the risk of HUA, particularly in women, in whom the risk of HUA increased up to four times compared to the reference group. A sex-based clinical strategy for HUA is necessary to reduce related complications and their socio-economic burden.

Background: A limited number of studies have explored the association between rheumatoid arthritis (RA) and heart failure (HF) based on HF subtype (ischemic and non-ischemic) and RA serostatus. Objective: This study aimed to examine the association between RA and incident HF, considering serostatus (seropositive RA[SPRA], seronegative RA[SNRA]) and HF subtype. Methods: This retrospective cohort utilized nationwide population data from the National Health Insurance Service (NHIS) of Korea. The study analyzed 46,975 RA patients (33,424 SPRA, 13,551 SNRA) diagnosed in 2010–2017, along with 140,925 matched non-RA controls. Results: The RA patients had a higher risk of overall HF (adjusted hazard ratio (aHR) 1.97, 95% confidence interval (CI) 1.68–2.32), and risk was more prominent for ischemic HF (aHR 2.24, 95% CI 1.86–2.71) than non-ischemic HF (aHR 1.36, 95% CI 0.97–1.90). Compared with controls, the risk of overall HF was increased in both SPRA (aHR 2.13, 95% CI 1.78–2.55) and SNRA (aHR 1.59, 95% CI 1.19–2.11), with a non-significant trend toward a higher risk in SPRA than in SNRA (aHR 1.35, 95% CI 0.99–1.83). For non-ischemic HF, the risk was increased in SPRA (aHR 1.60, 95% CI 1.12–2.28) but not in SNRA (aHR 0.71, 95% CI 0.32–1.51); however, this finding was based on a small number of events. Conclusions: This study demonstrates that RA was significantly associated with an increased risk of overall and ischemic HF, with a non-significant trend toward an increased risk of non-ischemic HF. The increased risk of ischemic HF was observed in both SPRA and SNRA, whereas the difference in non-ischemic HF risk by serostatus should be interpreted with caution due to the small number of events.