Psoriasis and Metabolic Disorders: A Comprehensive Meta-Analysis of Million Adults Worldwide

Psoriasis, a chronic inflammatory skin condition, and metabolic disorders, such as obesity, diabetes, and dyslipidemia, have long been recognized as distinct clinical entities. However, emerging evidence suggests a complex bidirectional relationship between these seemingly unrelated conditions. Psoriasis is characterized by an accelerated skin cell turnover, resulting in the formation of erythematous plaques with silvery scales. Metabolic disorders, on the other hand, encompass a range of conditions associated with abnormal metabolic processes, including insulin resistance, dyslipidemia, and chronic low-grade inflammation. It is intriguing to note that psoriasis is commonly associated with several metabolic comorbidities, with a higher prevalence observed in individuals with obesity, type 2 diabetes, and metabolic syndrome. Mounting evidence suggests that chronic inflammation plays a pivotal role in both psoriasis and metabolic disorders. Shared inflammatory mediators, such as tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and C-reactive protein (CRP), have been implicated in the pathogenesis of both conditions. Moreover, adipose tissue-derived hormones, known as adipokines, including leptin and adiponectin, exert modulatory effects on immune responses and may contribute to the link between psoriasis and metabolic abnormalities. Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, a comprehensive search across databases identified 16 eligible studies (1975-2023), totaling 6,623,379 participants. Inclusion criteria encompassed peer-reviewed observational studies focusing on adults and specified outcomes. Data extraction, quality assessment (Newcastle-Ottawa scale (NOS)), meta-analyses, and heterogeneity evaluations were conducted using rigorous methods. Psoriasis displayed a significant association with diabetes mellitus (DM, 18% increased incidence), hypertension (HTN, 35%), hyperlipidemia (19%), and obesity (25%). Substantial heterogeneity was observed in meta-analyses, particularly for DM. The NOS indicated varied study quality, with some studies categorized as a high or moderate risk of bias.