Insulin resistance impairs biologic agent response in moderate-to-severe plaque psoriasis: insights from a prospective cohort study in China

BACKGROUND: Psoriasis and insulin resistance (IR) are closely related, but it remains unclear whether IR affects the treatment of patients with psoriasis. OBJECTIVE: To investigate whether IR impairs the treatment response to biologic agents in patients with moderate-to-severe plaque psoriasis. METHODS: This project was based on a prospective cohort study design. Data were collected from the Shanghai Psoriasis Effectiveness Evaluation CoHort (SPEECH), which is a prospective cohort exploring treatment strategies for psoriasis in China. IR was assessed using triglyceride glucose-body mass index (TyG-BMI). Psoriasis severity was assessed using Psoriasis Area and Severity Index (PASI) and Physician Global Assessment (PGA). Multiple logistic regression was used to explore the differences between patients with high and low levels of IR. Subgroup and sensitivity analyses were performed to examine the robustness of the study results. RESULTS: A total of 290 patients were included in the analysis. Based on median TyG-BMI, the patients were divided into two groups: high and low IR. The high IR group exhibited a higher prevalence of diabetes, a higher BMI, and higher fasting blood glucose and triglyceride levels than the low IR group. Further analysis of treatment efficacy revealed that patients in the high IR group had lower PASI 75 [≥ 75% improvement in Psoriasis Area and Severity Index (PASI)], PASI 90 (≥ 90% improvement in PASI) and PGA 0/1 ('clear' or 'almost clear') response rates after 12 weeks of treatment. In the low IR group, 81.9% of patients achieved PASI 75, 58.3% achieved PASI 90 and 75.7% achieved PGA 0/1. However, the proportion of responses at each endpoint was significantly lower in the high IR group compared with the low IR group. The reduced PGA 0/1 response rate was more significant in the high IR group, indicated by lower odd ratios. Subsequent subgroup and sensitivity analyses produced consistent results. CONCLUSION: IR is associated with lower effectiveness of biologics in patients with psoriasis.