Distinct Characteristics of Patients with Gout and an Underweight or Normal Body Mass Index: A Single-Center Retrospective Cross-Sectional Study

Gout is an inflammatory arthritis triggered by monosodium urate crystal deposition, especially in obese patients. However, distinctions between the characteristics of obese and non-obese patients with gout remain unclear. We aimed to investigate the clinical differences by body mass index (BMI) with gout. We conducted a single-center retrospective cross-sectional study of 269 patients with gout from March 2020 to May 2024. Patients were classified into two groups: underweight/normal BMI and overweight/obesity. Baseline demographics, laboratory data, and clinical outcomes were compared between these groups. Stepwise logistic regression analysis was performed to identify predictors of underweight/normal BMI in gout patients. The underweight/normal BMI group included 35 patients (13.0%), characterized by older age, a higher proportion of females, and a lower prevalence of hypertension and alcohol consumption. This group also demonstrated lower uric acid, lipid profile, and alanine aminotransferase (ALT) levels but had a higher erythrocyte sedimentation rate. Logistic regression analysis identified female sex (odds ratio [OR] 3.831, 95% confidence interval [CI] 1.254-11.705, <i>p</i> = 0.018), presence of hypertension (OR 0.367, 95% CI 0.166-0.809, <i>p</i> = 0.013), total cholesterol (OR 0.990, 95% CI 0.982-0.999, <i>p</i> = 0.031), and ALT (OR 0.967, 95% CI 0.941-0.995, <i>p</i> = 0.019) as significant predictors of underweight/normal BMI gout. Understanding these characteristics may improve the identification of underweight/normal BMI subgroups, leading to improved approaches for gout management.