High burden of the metabolic syndrome and its component disorders in South Africans with psoriasis

Psoriasis is associated with cardiometabolic diseases (CMDs) in Caucasians, but no data is available from sub-Saharan populations on either CMD prevalence or psoriasis risk factors. Our aim was to investigate the prevalence of CMDs in a predominantly non-Caucasian cohort of South Africans with psoriasis and to determine the principal risk factors associated with psoriasis.

This was a cross-sectional case-control study of adult psoriasis patients (n = 103) and controls (n = 98), comparing sociodemographic, anthropometric, clinical, and biochemical characteristics. The groups were matched for gender, ethnicity, and body mass index (BMI).

The prevalence of metabolic syndrome (MetS) (52.4% vs. 33.7%; P = 0.007), type 2 diabetes (T2D) (25.2% vs. 4.1%; P < 0.0001), and hypertension (70.9% vs. 46.6%; P = 0.001) were all higher in the psoriasis group. High-sensitivity CRP was higher in psoriasis patients than controls (4.70 (2.00, 10.9) vs. 2.00 (1.10, 4.80) ng/ml; P < 0.0005). Multivariable logistic regression analysis showed that severe psoriasis was independently associated with MetS (odds ratio [95% CIs]: 4.42 [1.72, 11.4]; P = 0.002), T2D (11.3 [3.07, 41.3]; P = 0.0002), and hypertension (2.48 [0.97, 6.32]; P = 0.05), whilst for psoriasis the principal risk factors were smoking (3.87 [1.97, 7.63]; P < 0.0001) and hsCRP (1.05 [1.00, 1.10]; P = 0.029), with completion of high school (0.23 [0.11, 0.48]; P < 0.0001) being protective.

In this population, psoriasis is characterized by a high burden of CMDs, particularly in those subjects with severe psoriasis. Inflammation plays a role in the etiology of psoriasis, whilst smoking and poor education further increase disease risk.