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

Causal relationship between plasma lipidome and rosacea: a Mendelian randomization analysis

Background

Rosacea is a common chronic inflammatory skin disease. Limited studies reported the association between plasma lipidome and rosacea.

Methods

We employed a two-sample Mendelian randomization (MR) study to assess the causality between plasma lipidome and rosacea. Plasma lipidome association genome-wide association study (GWAS) data were collected. The inverse variance weighted (IVW) method was utilized as the principal method in our Mendelian randomization (MR) study; we also used the MR-Egger, weighted median, simple mode, and weighted mode methods. The MR-Egger intercept test, Cochran's Q test, MR-Pleiotropy RESidual Sum and Outlier (MR-PRESSO), and leave-one-out analysis were conducted to identify heterogeneity and pleiotropy.

Results

A total of 179 lipid species were analyzed; among them, five lipid species were closely related to rosacea. Two species of sterol ester [sterol ester (27:1/22:6) and sterol ester (27:1/15:0)], two species of phosphatidylethanolamine [phosphatidylethanolamine (O-18:2_20:4) and phosphatidylethanolamine (18:0_20:4)], and one species of sphingomyelin [sphingomyelin (d34:0)] were causally associated with rosacea (P < 0.05). All of them play protective roles in patients with rosacea. No heterogeneity or pleiotropy was observed.

Conclusion

This study provided new evidence of the relationship between plasma lipidome and rosacea. Our MR suggested that five lipid species play protective roles in rosacea progression. These could be novel and effective ways to treat rosacea.

Correlation between cardiometabolic index and psoriasis: a cross-sectional analysis using NHANES data

Background

Psoriasis is closely associated with metabolic health. The Cardiometabolic Index (CMI) is an innovative and easily obtainable metric employed to assess cardiometabolic health. This study aims to examine the possible relationship between CMI and psoriasis.

Methods

Data from four successive cycles of the National Health and Nutrition Examination Survey (NHANES) conducted between 2003-2004 and 2009-2014 were employed. This encompassed adults with self-reported psoriasis diagnoses and comprehensive information necessary for calculating the CMI. The calculation formula for CMI is Triglycerides (TG)/High-density lipoprotein cholesterol (HDL-C) × WHtR (WHtR = waist circumference/height). A multivariable logistic regression model was utilized to examine the linear relationship between CMI and psoriasis. Subgroup analyses were conducted to investigate potential contributing factors. The linear relationship was further established using smooth curve fitting.

Results

This study, utilizing NHANES data, comprised a cohort of 7,327 American adults. The multivariable logistic regression analysis indicated that in the fully adjusted model, people with the greatest CMI had a 71% increased probability of psoriasis relative to those with the lowest CMI (OR = 1.71; 95% CI, 1.11-2.61, P < 0.05). Smooth curve fitting demonstrated a linear connection between CMI and psoriasis (P < 0.05). The subgroup analysis revealed no significant interactions between CMI and specific subgroups (all interactions P > 0.05).

Conclusion

Our research indicates a substantial linear correlation between CMI and psoriasis in American adults. This method facilitates the identification of groups at increased risk for psoriasis, therefore guiding therapeutic solutions and public health activities to improve metabolic and dermatological health outcomes.

Low apolipoprotein A1 and high apolipoprotein B levels indicate specific lipid changes in treatment naïve early psoriatic arthritis

OBJECTIVES

To investigate serum lipid profile in early, treatment-naïve psoriatic arthritis (PsA) and to determine whether changes in classical lipids or apolipoproteins are specific to PsA.

METHODS

Total cholesterol, non-high-density lipoprotein cholesterol (non-HDL-c), low-density lipoprotein cholesterol (LDL-c), HDL-c, triglycerides, apolipoprotein B (ApoB) and apolipoprotein A1 (ApoA1) were compared in newly diagnosed untreated PsA patients (n=75) to sex- and age-matched controls (healthy control (HC)) (n=61) and early untreated rheumatoid arthritis (RA) patients (n=50).

RESULTS

Among classical lipid measurements, HDL-c levels were lower in PsA than in HC and RA (df 2, χ210, p=0.006, PsA vs HC p=0.013). Significant differences in ApoA1 and ApoB levels were observed between PsA, RA and controls. ApoB was higher in PsA than in RA patients but lower than in controls (df2, χ243.8; p<0.001). ApoA1 was markedly lower in PsA patients compared with both RA and controls (df2, χ2118.9; p<0.001). In regression models, the levels of ApoA1, adjusted for additional factors, were predictive of PsA diagnosis with 90.6% accuracy. In receiver operating characteristic analysis, ApoA1 was predictive of the diagnosis of PsA with a specificity of 82.4% and a sensitivity of 83.8% at an optimal cut-off value of 1403 µg/mL (area under the curve (95% CI), 0.886 (0.83 to 0.941)).

CONCLUSION

Early, treatment-naïve PsA patients exhibit a distinct pro-atherogenic lipid profile, characterised by decreased ApoA1 and increased ApoB levels, distinguishing them from early RA patients and healthy controls. These findings highlight the potential of apolipoprotein measurements to serve as more accurate indicators of lipid disturbances in PsA than traditional serum lipids and as aid to diagnosis of patients presenting with early arthritis.

Causal association between cardiovascular risk factors and common skin diseases: A multivariate Mendelian randomization study

Cardiovascular diseases and dermatological conditions are prevalent health issues worldwide. Previous studies have suggested that risk factors for cardiovascular diseases may be associated with the development of dermatological conditions. However, the causal association between these factors remain unclear. This study utilized data from genome-wide association studies and applied Mendelian randomization (MR) to explore the potential causal association between cardiovascular risk factors and common dermatological conditions. Genetic variants significantly associated with low-density lipoprotein cholesterol (LDL-C), serum uric acid, blood glucose, and hypertension were selected as instrumental variables. We employed inverse variance weighted, MR Egger, and weighted mode methods for analysis. Sensitivity analyses, including Cochran Q test, MR-Egger intercept test, MR-PRESSO global test, and leave-one-out analysis, were conducted to ensure the robustness of the results. The MR analysis indicated a positive association between LDL-C levels and the risk of psoriasis (odds ratio [OR] = 1.23, 95% confidence interval [CI]: 1.03-1.47, P = .02). Additionally, hypertension and serum uric acid levels were positively associated with the risk of dermatitis eczema (hypertension: OR = 2.77, 95% CI: 1.23-6.24, P = .01; serum uric acid: OR = 1.09, 95% CI: 1.01-1.06, P = .01). This study provides evidence of a potential causal association between LDL-C levels and psoriasis, as well as between hypertension and serum uric acid levels and dermatitis eczema. These findings highlight the potential importance of cardiovascular health management in the prevention and treatment of common dermatological conditions. Further research is needed to validate these results and explore the underlying biological mechanisms.

Causal association between B cell count and psoriasis using two-sample Mendelian randomization

To investigate the causality between B cell count and psoriasis by Mendelian randomization (MR). Collected B cell count and psoriasis data from IEU Open GWAS Project. Employed inverse variance weighting (IVW), MR-Egger, WM, weighted mode for analysis, ensuring result robustness. Assessed horizontal pleiotropy with MR-Egger, detected outliers using MR-PRESSO and examined instrumental variables heterogeneity with Cochran's Q-test. The IVW method suggested an association between a genetically predicted memory B cell count and the risk of psoriasis vulgaris. IVW results also showed no causality between other exposure factors and the corresponding outcomes. Also, the global test of MR-PRESSO analysis showed a significant association between a genetically predicted transitional absolute B cell count and the lower risk of psoriasis vulgaris. MR-Egger regression showed that horizontal pleiotropy did not influence the analysis results. We found that memory B cell absolute counts are associated with a lower risk of psoriasis. These data further elucidate the role of memory B cells in psoriasis and provide new options for psoriasis treatment.

Assessing the genetic associations between plasma lipidomic profiles and psoriasis vulgaris

Several studies have indicated a potential causal relationship between plasma standard lipids, such as high-density lipoprotein-cholesterol (HDL-C), low-density lipoprotein-cholesterol (LDL-C), triglycerides (TG), and total cholesterol (TC), and psoriasis. However, few studies have offered causal evidence of lipid species beyond these standard lipids. We conducted an analysis using a genome-wide association study (GWAS) dataset comprising 179 lipid species, including 13 types across four major categories, to identify instrumental variables (IVs) associated with plasma lipids. We utilized two GWAS datasets from the IEU and Finngen for psoriasis vulgaris as the outcome. A two-sample Mendelian randomization (MR) analysis was used to explore the causal relationship between 179 lipid species and psoriasis vulgaris in two datasets. Lipid species showing causal association in both psoriasis datasets were compared for overlap. Our study identified potential causal relationships between six lipid species and psoriasis vulgaris: phosphatidylcholine (16:1_18:2), phosphatidylcholine (18:0_18:2), phosphatidylcholine (18:1_20:4), phosphatidylethanolamine (16:0_18:2), phosphatidylinositol (18:0_20:3), and triacylglycerol (50:1). In summary, elevated plasma levels of phosphatidylcholine (16:1_18:2), phosphatidylcholine (18:0_18:2), phosphatidylethanolamine (16:0_18:2), phosphatidylinositol (18:0_20:3), and triacylglycerol (50:1) may increase the risk of psoriasis vulgaris. Conversely, plasma phosphatidylcholine (18:1_20:4) may play a protective role against psoriasis vulgaris.

Managing the Patient with Psoriasis and Metabolic Comorbidities

Epidemiological data demonstrate strong associations between psoriasis and metabolic comorbidities, including obesity, hypertension, diabetes mellitus, dyslipidemia, and non-alcoholic fatty liver disease. The presence of metabolic comorbidities significantly influences the selection and effectiveness of pharmacological treatments. Some drugs should be prescribed with caution in patients with metabolic comorbidities because of an increased risk of adverse events, while others could have a reduced effectiveness. The aim of this narrative review is to highlight the challenges that healthcare professionals may face regarding the management of psoriasis in patients with metabolic comorbidities. In the first part of the article, the epidemiological association between psoriasis and metabolic comorbidities and their pathogenetic mechanisms is summarized. The second part describes the efficacy and safety profile of conventional and biologic drugs in patients with selected metabolic comorbidities including obesity, non-alcoholic fatty liver disease/hepatic steatosis, and diabetes. Finally, the role of pharmacological and non-pharmacological interventions, such as diet, alcohol abstinence, physical activity, and smoking avoidance is discussed. In conclusion, the choice of the best approach to manage patients with psoriasis with metabolic comorbidities should encompass both tailored pharmacological and individualized non-pharmacological interventions.

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.

Investigating causal associations among gut microbiota, metabolites, and psoriatic arthritis: a Mendelian randomization study

BACKGROUND

Currently, there has been observed a significant alteration in the composition of the gut microbiome (GM) and serum metabolites in patients with psoriatic arthritis (PsA) compared to healthy individuals. However, previous observational studies have shown inconsistent results regarding the alteration of gut microbiota/metabolites. In order to shed light on this matter, we utilized Mendelian randomization to determine the causal effect of GM/metabolites on PsA.

METHODS

We retrieved summary-level data of GM taxa/metabolites and PsA from publicly available GWAS statistics. Causal relationships between GM/metabolites and PsA were determined using a two-sample MR analysis, with the IVW approach serving as the primary analysis method. To ensure the robustness of our findings, we conducted sensitivity analyses, multivariable MR analysis (MVMR), and additional analysis including replication verification analysis, LDSC regression, and Steiger test analysis. Furthermore, we investigated reverse causality through a reverse MR analysis. Finally, we conducted an analysis of expression quantitative trait loci (eQTLs) involved in the metabolic pathway to explore potential molecular mechanisms of metabolism.

RESULTS

Our findings reveal that eight GM taxa and twenty-three serum metabolites are causally related to PsA (P < 0.05). Notably, a higher relative abundance of Family Rikenellaceae (ORIVW: 0.622, 95% CI: 0.438-0.883, FDR = 0.045) and elevated serum levels of X-11538 (ORIVW: 0.442, 95% CI: 0.250-0.781, FDR = 0.046) maintain significant causal associations with a reduced risk of PsA, even after adjusting for multiple testing correction and conducting MVMR analysis. These findings suggest that Family Rikenellaceae and X-11538 may have protective effects against PsA. Our sensitivity analysis and additional analysis revealed no significant horizontal pleiotropy, reverse causality, or heterogeneity. The functional enrichment analysis revealed that the eQTLs examined were primarily associated with glycerolipid metabolism and the expression of key metabolic factors influenced by bacterial infections (Vibrio cholerae and Helicobacter pylori) as well as the mTOR signaling pathway.

CONCLUSION

In conclusion, our study demonstrates that Family Rikenellaceae and X-11538 exhibit a strong and negative causal relationship with PsA. These particular GM taxa and metabolites have the potential to serve as innovative biomarkers, offering valuable insights into the treatment and prevention of PsA. Moreover, bacterial infections and mTOR-mediated activation of metabolic factors may play an important role in this process.

Causality of unsaturated fatty acids and psoriasis a Mendelian randomization study

Background

Many observational studies have identified a link between unsaturated fatty acids and psoriasis. However, they contain reverse causality and confounding factors, and there is no definite causal study between unsaturated fatty acids and psoriasis.

Objectives

Analysis of causality between unsaturated fatty acids and psoriasis by Mendelian randomization.

Methods

We used IEU Open GWAS Project, omega-3 PUFA and omega-6 PUFA data from 114,999 subjects, MUFA data from 13,535 subjects, and psoriasis data from 4,510 cases and 212,242 controls were included. We employed the inverse-variance weighted (IVW) method as the primary analytical approach and four additional MR methods. Moreover, we performed heterogeneity and horizontal pleiotropy assessments using Cochrane's Q and MR-Egger intercept tests, respectively. Finally, we performed sensitivity analyses to enhance our findings' precision and veracity.

Results

IVW results showed no causal effect of omega-3 PUFA on psoriasis (p = 0.334; OR, 0.909; 95% CI, 0.748-1.104), omega-6 PUFA cause psoriasis (p = 0.046; OR, 1.174; 95% CI, 1.003-1.374), MUFA cause psoriasis (p = 0.032; OR, 1.218; 95% CI, 1.018-1.457), no causal effect of omega-3 PUFA in psoriasis (p = 0.695; OR, 0.989; 95% CI, 0.937-1.044), no causal effect of omega-6 PUFA in psoriasis (p = 0.643; OR, 1.013; 95% CI, 0.960-1.068), psoriasis is not causal to MUFA (p = 0.986; OR, 1.000; 95% CI, 0.949-1.055). Heterogeneity, horizontal pleiotropy, and sensitivity analyses showed reliable results.

Conclusion

We found that circulating omega-6 PUFA and MUFA cause psoriasis, while omega-3 PUFA do not. Treatments that lower circulating omega-6 PUFA and MUFA are effective in psoriasis. After a better understanding of fatty acid intake and circulation, the population can be advised to regulate their diet.

No causal effect of genetically determined circulating homocysteine levels on psoriasis in the European population: evidence from a Mendelian randomization study

Background

Although numerous studies demonstrated a link between plasma homocysteine (Hcy) levels and psoriasis, there still exists a certain level of controversy. Therefore, we conducted a Mendelian randomization study to investigate whether homocysteine plays a causative role in the development or exacerbation of psoriasis.

Methods

A two-sample Mendelian randomization (MR) analysis was conducted. Summary-level data for psoriasis were acquired from the latest R9 release results from the FinnGen consortium (9,267 cases and 364,071 controls). Single nucleotide polymorphisms (SNPs) robustly linked with plasma Hcy levels at the genome-wide significance threshold (p < 5 × 10-8) (18 SNPs) were recognized from the genome-wide meta-analysis on total Hcy concentrations (n = 44,147 participants) in individuals of European ancestry. MR analyses were performed utilizing the random-effect inverse variance-weighted (IVW), weighted median, and MR-Egger regression methods to estimate the associations between the ultimately filtrated SNPs and psoriasis. Sensitivity analyses were conducted to evaluate heterogeneity and pleiotropy.

Results

MR analyses revealed no causal effects of plasma Hcy levels on psoriasis [IVW: odds ratio (OR) = 0.995 (0.863-1.146), p = 0.941; weighed median method: OR = 0.985 (0.834-1.164), p = 0.862; MR-Egger regression method: OR = 0.959 (0.704-1.305), p = 0.795]. The sensitivity analyses displayed no evidence of heterogeneity and directional pleiotropy, and the causal estimates of Hcy levels were not influenced by any individual SNP.

Conclusion

Our study findings did not demonstrate a causal effect of genetically determined circulating Hcy levels on psoriasis.