Psoriasis and type 2 diabetes mellitus: epidemiology, shared mechanisms, and therapeutic implications: a narrative review.

Psoriasis is a chronic immune-mediated inflammatory disorder increasingly recognized as a systemic disease rather than an isolated cutaneous condition. In addition to its dermatologic burden, psoriasis is associated with multiple metabolic comorbidities, among which type 2 diabetes mellitus (T2DM) is particularly important because of its prevalence, long-term complications, and potential bidirectional relationship with psoriatic inflammation. Epidemiologic studies consistently suggest that patients with psoriasis, especially those with moderate-to-severe or longstanding disease, have a higher prevalence and incidence of T2DM than the general population. Conversely, metabolic dysfunction, particularly insulin resistance and obesity-related inflammation, may contribute to psoriasis onset and severity. Shared pathogenic pathways include chronic systemic inflammation, dysregulated adipokines, endothelial dysfunction, oxidative stress, and overlapping genetic susceptibility. These mechanistic links have important clinical implications for screening, cardiovascular risk assessment, and therapeutic decision-making. Emerging evidence also suggests that some antidiabetic agents and biologic therapies may influence both metabolic and dermatologic outcomes, although current interventional evidence remains limited and heterogeneous. This narrative review summarizes the epidemiologic evidence supporting the psoriasis-T2DM association, examines shared inflammatory and metabolic mechanisms, and discusses the clinical and therapeutic implications of this comorbidity. Recognizing psoriasis as a systemic inflammatory disease with substantial metabolic consequences may support earlier risk stratification, multidisciplinary care, and more individualized treatment strategies.