Psoriasis Severity and Cardiometabolic Risk Factors in a Representative US National Study

A genome-wide cross-trait analysis identifies shared loci and causal relationships of obesity and lipidemic traits with psoriasis

Background

Obesity and dyslipidemia, major global health concerns, have been linked to psoriasis, but previous studies faced methodological limitations and their shared genetic basis remains unclear. This study examines various obesity-related and lipidemic traits as potential contributors to psoriasis development, aiming to clarify their genetic associations and potential causal links.

Methods

Summary statistics from genome-wide association studies (GWAS) conducted for obesity-related traits (body mass index (BMI), waist-to-hip ratio (WHR), and waist-to-hip ratio adjusted for the body mass index (WHRadjBMI)) and lipidemic traits (high-density lipoprotein (HDL), LDL, triglyceride (TG), total Cholesterol (TC), apolipoprotein A1 (apoA1), apolipoprotein B (apoB), and apolipoprotein E (apoE)) and psoriasis, all in populations of European ancestry, were used. We quantified genetic correlations, identified shared loci and explored causal relationship across traits.

Results

We found positive genetic correlation between BMI and psoriasis (rg=0.22, p=2.44×10-18), and between WHR and psoriasis (rg=0.19, p=1.41×10-12). We further found the positive genetic correlation between psoriasis and WHRadjBMI(rg=0.07, p=1.81×10-2) the genetic correlation, in while the effect of BMI was controlled for. We identified 14 shared loci underlying psoriasis and obesity-related traits and 43 shared loci between psoriasis and lipidemic traits via cross-trait meta-analysis. Mendelian randomization (MR) supported the causal roles of BMI (IVW OR=1.483, 95%CI=1.333-1.649), WHR (IVW OR=1.393, 95%CI=1.207-1.608) and WHRadjBMI (IVW OR=1.18, 95%CI=1.047-1.329) in psoriasis, but not observe any significant association between lipidemic traits and the risk of psoriasis. Genetic predisposition to psoriasis did not appear to affect the risk of obesity and lipidemic traits.

Conclusions

An intrinsic link between obesity-related traits and psoriasis has been demonstrated. The genetic correlation and causal role of obesity-related traits in psoriasis highlight the significance of weight management in both the prevention and treatment of this condition.

The relationship between blood lipid and risk of psoriasis: univariable and multivariable Mendelian randomization analysis

Background

Psoriasis is a chronic inflammatory skin disease. Dyslipidemia may be a risk factor of psoriasis. But the causal relationship between psoriasis and blood lipid still remains uncertain.

Methods

The two data of blood lipid were obtained from UK Biobank (UKBB) and Global Lipid Genetics Consortium Results (GLGC). The primary and secondary database were from large publicly available genome-wide association study (GWAS) with more than 400,000 and 170,000 subjects of European ancestry, respectively. The psoriasis from Finnish biobanks of FinnGen research project for psoriasis, consisting of 6,995 cases and 299,128 controls. The single-variable Mendelian randomization (SVMR) and multivariable Mendelian randomization (MVMR) were used to assess the total and direct effects of blood lipid on psoriasis risk.

Results

SVMR estimates in primary data of blood lipid showed low-density lipoprotein cholesterol (LDL-C) (odds ratio (OR): 1.11, 95%, confidence interval (CI): 0.99-1.25, p = 0.082 in stage 1; OR: 1.15, 95% CI: 1.05-1.26, p = 0.002 in stage 2; OR: 1.15, 95% CI: 1.04-1.26, p = 0.006 in stage 3) and triglycerides (TG) (OR: 1.22, 95% CI: 1.10-1.35, p = 1.17E-04 in stage 1; OR: 1.15, 95% CI: 1.06-1.24, p = 0.001 in stage 2; OR: 1.14, 95% CI: 1.05-1.24, p = 0.002 in stage 3) had a highly robust causal relationship on the risk of psoriasis. However, there were no robust causal associations between HDL-C and psoriasis. The SVMR results in secondary data of blood lipid were consistent with the primary data. Reverse MR analysis showed a causal association between psoriasis and LDL-C (beta: -0.009, 95% CI: -0.016- -0.002, p = 0.009) and HDL-C (beta: -0.011, 95% CI: -0.021- -0.002, p = 0.016). The reverse causation analyses results between psoriasis and TG did not reach significance. In MVMR of primary data of blood lipid, the LDL-C (OR: 1.05, 95% CI: 0.99-1.25, p = 0.396 in stage 1; OR: 1.07, 95% CI: 1.01-1.14, p = 0.017 in stage 2; OR: 1.08, 95% CI: 1.02-1.15, p = 0.012 in stage 3) and TG (OR: 1.11, 95% CI: 1.01-1.22, p = 0.036 in stage 1; OR: 1.09, 95% CI: 1.03-1.15, p = 0.002 in stage 2; OR: 1.07, 95% CI: 1.01-1.13 p = 0.015 in stage 3) positively correlated with psoriasis, and there had no correlation between HDL-C and psoriasis. The results of the secondary analysis were consistent with the results of primary analysis.

Conclusions

Mendelian randomization (MR) findings provide genetic evidence for causal link between psoriasis and blood lipid. It may be meaningful to monitor and control blood lipid level for a management of psoriasis patients in clinic.

Metabolic Syndrome Screening and Nutritional Status of Patients with Psoriasis: A Scoping Review

Background: Patients with plaque psoriasis have an increased risk of metabolic syndrome. However, no studies have assessed the nutritional status or screening methods of this population. Aims: This review aimed to identify and summarise metabolic syndrome screening criteria and the tools/methods used in nutrition assessment in patients with plaque psoriasis. Data synthesis: PubMed, Web of Science, Ovid and Scopus were searched from inception to March 2023, following the Arkensey and O'Malley framework, to identify articles that report nutritional assessment methods/tools and metabolic screening criteria. Twenty-one studies were identified. Overall, these studies used four different screening criteria to define metabolic syndrome. Patients with psoriasis had a high prevalence of metabolic syndrome and had a poor nutritional status compared to controls. However, only anthropometric measures such as weight, height and waist circumference were employed to determine the nutritional status. Only two studies assessed the vitamin D status. Conclusions: Patients with psoriasis have a poor nutritional status, and they are at risk of nutrient deficiencies. However, these health aspects are not routinely assessed and may increase the risk of malnutrition among these patients. Therefore, additional assessments, such as body composition and dietary assessment, are needed to determine the nutritional status to provide a suitable intervention.

The cardiometabolic conditions of psoriatic disease

Psoriasis (PsO) and psoriatic arthritis (PsA), together known as psoriatic disease (PsD), are immune-mediated diseases with a chronic and relapsing course that affect the skin, the joints or both. The pathophysiology of PsO is complex and involves abnormal expression of keratinocytes and infiltration of the skin with dendritic cells, macrophages, neutrophils and T lymphocytes. Around 30% of patients with PsO develop arthritis with axial and/or peripheral manifestations. Both PsO and PsA share similar Th1- and Th17-driven inflammation, with increased production of inflammatory cytokines, including TNFα, IFN-γ, IL-17, IL-22, IL-23 in the skin and the synovial membrane. PsD is associated with a high burden of cardiometabolic diseases such as hypertension, diabetes, dyslipidemia, obesity, metabolic syndrome and cardiovascular (CV) complications as compared to the general population. These comorbidities share common immunopathogenic pathways linked to systemic inflammation, and are associated with the extent and severity of the disease. Morever, they can influence treatment outcomes in PsD. In this short review, we summarize the available evidence on the epidemiology, clinical aspects and mechanisms of cardiometabolic conditions in patients with PsD. We also discuss the impact of targeted treatments such as methotrexate and biological agents on these cardiometabolic conditions.