Association of Triglyceride-Glucose Index and Its Obesity-Adjusted Derivatives with Psoriasis: Findings from a Cross-Sectional Chinese study

Background: The triglyceride-glucose (TyG) index and its anthropometric-adjusted derivatives, including TyG-body mass index (TyG-BMI) and TyG-waist circumference (TyG-WC), are surrogate markers of insulin resistance. Although metabolic dysfunction is implicated in psoriasis, evidence on these indices and psoriasis risk in Asian populations is scarce. Methods: We conducted a cross-sectional study of 3,314 Chinese adults recruited from Deyang Hospital, Chengdu University of Traditional Chinese Medicine (January 2022–June 2023). Demographic, lifestyle, anthropometric, and biochemical data were collected using standardized protocols. TyG, TyG-BMI, and TyG-WC were calculated and categorized into quartiles. Logistic regression models estimated odds ratios (ORs) and 95% confidence intervals (CIs), adjusting for age, sex, body mass index, blood pressure, lipids, high-sensitivity C-reactive protein, smoking, and alcohol consumption. Results: Among 3,314 participants, 1,560 had psoriasis and 1,754 did not. Patients with psoriasis were older, more frequently male, and exhibited higher rates of smoking, alcohol intake, obesity, hypertension, dyslipidemia, and systemic inflammation (P < 0.05 for all). The TyG index and its derivatives were significantly elevated in the psoriasis group. In fully adjusted models, higher quartiles of TyG, TyG-BMI, and TyG-WC were strongly associated with psoriasis risk. Compared with quartile 1, adjusted ORs (95% CIs) for quartile 4 were 8.91 (3.42–23.19) for TyG, 4.64 (2.18–9.90) for TyG-BMI, and 18.35 (4.80–70.22) for TyG-WC (all P for trend < 0.001). Each standard deviation increase in TyG, TyG-BMI, and TyG-WC corresponded to 58%, 43%, and 94% higher risks of psoriasis, respectively. Conclusions: Elevated TyG, TyG-BMI, and TyG-WC are independently associated with psoriasis in Chinese adults. These simple, cost-effective indices may aid in identifying individuals at high risk for psoriasis, with potential utility in preventive screening.