The Occurrence of Metabolic Risk Factors Stratified by Psoriasis Severity: A Swedish Population-Based Matched Cohort Study

Abstract

Purpose

To assess the relative risk of metabolic risk factors in patients stratified by psoriasis severity compared with population controls.

Patients and Methods

A retrospective cohort study was conducted using national Swedish registers. Adult patients with psoriasis were selected if they had a dispensing of anti-psoriasis prescription (2007–2013) and at least one diagnosis within five years before the dispensing date. The patients with psoriasis were matched 1:10 to controls from the general population on birth year, sex, and county. The cohort was further divided into three disease severity groups (mild, moderate, or severe) based on their dispensed anti-psoriasis medication. Subjects were followed from the index date until censoring. We applied flexible parametric modeling to understand the risks of the incident comorbidities hypertension, hypercholesterolemia, and diabetes mellitus among patients with psoriasis from 6 months through 10 years. Hazard ratios and predicted risk (ie, 1 minus the survival probability) of comorbidities were reported.

Results

The hazard of hypertension, hypercholesterolemia, and diabetes mellitus is higher among psoriasis patients compared with population controls, and the hazard ratio increases with psoriasis severity. For example, HRs of hypertension for patients with mild, moderate, and severe psoriasis are 1.29 (95% CI: 1.27–1.32), 1.35 (95% CI: 1.32–1.38), and 1.73 (95% CI: 1.64–1.82), respectively. The predicted risk of hypertension, hypercholesterolemia, and diabetes mellitus among patients with severe psoriasis at year ten was 0.58 (95% CI: 0.56, 0.59), 0.33 (95% CI: 0.32, 0.35), and 0.21 (95% CI: 0.20, 0.23), respectively, while it was 0.42 (0.41, 0.43), 0.23 (0.22, 0.23), 0.11 (0.10, 0.11) among controls, respectively. The predicted risk at year ten was similar among patients with mild or moderate psoriasis.

Conclusion

The HRs and predicted risks of metabolic risk factors are higher among patients with psoriasis compared with matched controls and are more prominent among the severe psoriasis group.

Keywords:

• psoriasis severity
• predicted risk
• survival probability
• population-based
• metabolic risk factors

Acknowledgments

The authors like to express their appreciation to Anders Sundström, Ina Anveden-Berglind, Sean McElligott, Sverrir Valgardsson, and Nan Li for taking part in conceptualizing the study.

Abbreviations

HTN, hypertension; CVD, cardiovascular diseases; DM, diabetes mellitus; HR, hazard ratio; CI, confidence interval; NPR, national patient register; PDR, prescribed drug register; CDR, cause of death register; ATC, anatomical therapeutic chemical; ICD, International Classification of Diseases.

Data Sharing Statement

This observational study is based on individual patient data from the national Swedish health registers. We are not allowed, by law, to publicly share these data. Therefore, we are not able to make these data fully available to the public.

Ethical Approval and Informed Consent

The study was approved by the Regional Ethical Review Board at Karolinska Institutet (2009/1250_31/4).

Author Contributions

All authors made substantial contributions to conception and design, acquisition of data, or analysis and interpretation of data; took part in drafting the article or revising it critically for important intellectual content; gave final approval of the version to be published; and agree to be accountable for all aspects of the work.

Disclosure

M Hajiebrahimi and TML Andersson have no conflict of interest. D Hägg and M Linder are employees at CPE, which receives grants from several entities (pharmaceutical companies, regulatory authorities, contract research organizations) for the performance of drug safety and drug utilization studies. C Song and R Villacorta are employees of Janssen.

Additional information

Funding

This project was funded via the public–private real-world evidence collaboration between Karolinska Institutet and Janssen Pharmaceuticals (contract: 5–63/2015).