European Journal of Cardiovascular Medicine

Psoriasis is a chronic, disfiguring, proliferative and inflammatory ailment of skin characterized by keratinocyte hyper-proliferation, abnormal keratinocyte differentiation and immune-cell infiltration into the epidermis and dermis. ^[1] The most typical abrasion involves red, crusty, tightly demarcated, indurated plaques, existing mainly over scalp and extensor surfaces. The ailment is extremely inconstant in duration and spell of flares. ^[2] Disease presents with a bimodal distribution of age at onset, with a peak between 15 and 20 years and another peak between 55 and 60 years. Psoriasis is associated with Psoriatic Paronychia and Psoriatic Arthritis. ^[3]

There are several psoriasis phenotypes. The most common clinical variant effecting nearly 85–90% of all patients is Psoriasis Vulgaris, recognized by elevated, distinct, erythematous lesions with silvery scale, mostly effecting scalp, knees, sacral region and elbows. ^[4] Overall prevalence of Psoriasis ranges from 0·1% in east Asia to 1·5% in western Europe; highest being in high-income countries. Prevalence and incidence are lower in children compared to adults and equal across both genders. ^[5]

Vitamin D is a fat-soluble steroid hormone. 25-hyroxy vitamin D is the most stable form with a half-life of 2–3 weeks, hence reliable medical indicator of vitamin D status. ^[6] Vitamin D has pleotropic functions. It controls calcium homeostasis by acting as a hormone as well as exercises autocrine/paracrine effects on CYP27B1 and VDR expressing tissues. ^[7]

In addition, vitamin D may reduce the risk of psoriasis by inhibiting T-cell proliferation/Th1 development, tempering antigen presenting cell (APCs) function, bringing hypo-responsiveness to antigens, decreasing the levels of IL-2, IL-17, IL-8, INF-α and INF-γ, enhancing manufacture of IL-10 and regulatory T cells. ^[8,9]

Vitamin D regulates the synthesis and release of human beta-defensin 2 (HBD2), antimicrobial peptides and cathelicidin which take part in the etiopathogenesis of psoriasis. Various studies have reported the involvement of vitamin D in the pathogenesis of different skin diseases, including Psoriasis. ^[10]

In this context, due to uncertain mechanisms, the intricate relationship between vitamin D levels and chronic autoimmune or inflammatory diseases such as Psoriasis, becomes obvious. So, this case-control study was designed to determine the serum 25-hydroxy vitamin D levels and its association, if any, with various sociodemographic and clinicopathological parameters of patients with psoriasis.

This case–control study included thirty outpatients. Patients with psoriasis were selected consecutively from the dermatology outpatient department.

The diagnosis of plaque psoriasis was made clinically. Inclusion criteria for patients were age between 18 to 60 years, not treated with oral and topical steroids, immunosuppressants and vitamin D supplements, not undergoing current phototherapy and presence of chronic inflammatory diseases like systemic lupus erythematosus, multiple sclerosis, inflammatory disease and malignancy.

Clinical and Laboratory Parameters

Details of age, sex, sun exposure per day, history of physical exercise, history of smoking, history of alcohol intake and associated disease were recorded for both patients and control subjects. Details of the duration of psoriasis, age at onset and positive family history were recorded. The severity of psoriasis was assessed according to the PASI.15 Fitz Patrick’s skin type was assessed. The weight, height and waist circumference were measured. Body mass index (BMI) was calculated.16 The blood pressure of the patient was taken after 5 minutes of rest and the average of two readings was recorded. Five milliliters of blood were drawn and fasting blood sugar (FBS), triglycerides (TAG) and high-density lipoproteins (HDL) were analyzed. Serum 25(OH) D was assessed by chemiluminescent immunoassay in the biochemistry lab of our hospital and classified according to severity.

The levels of serum total calcium, ionized calcium, urea, creatinine, phosphorus, ALT, AST, total protein, and albumin were measured. Intact parathormone (PTH), alkaline phosphatase, and 25(OH) D3 levels in the patient and control groups were analyzed using standard methods. C-reactive protein (CRP) was measured with the nephelometric method, and the erythrocyte sedimentation rate (ESR) was measured with the Westergren method.

Statistical Analysis

Data were entered in Microsoft Excel and were further analyzed in SPSS version 25. For epidemiological results, graphical and tabular presentations were done. Continuous variables were expressed as the mean (±SD) or as median whereas categorical variables were expressed as number (%). The Kolmogorov–Smirnov test was used to verify the normality of distribution. Quantitative data were described using range (minimum and maximum), mean, SD, and median. Significance of the obtained results was judged at the 5% level. The tests used were c2 test, Monte Carlo correction, F test (analysis of variance), Kruskal–Wallis test, and receiver operating characteristic curve.

There was nonsignificant difference between the studied groups regarding age and sex (Table 1). The mean age of psoriasis in Group II was 38.95±3.95 years and 39.0±4.55 years in Group III. There is significant decrease in the level of serum vitamin D in moderate and severe patient groups compared with the control group whereas nonsignificant difference existed with group II.

Decreased 25 OH vitamin D serum level was found in psoriatic patients. The 25 OH vitamin D serum level may be used as a marker of psoriasis severity and response to treatment. But PASI has higher sensitivity, specificity, PPV, and NPV for differentiation of psoriatic patients from controls, mild cases from moderate and severe cases, and severe cases from mild and moderate cases. 

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2. Bikle DD, Gee E, Pillai S. Regulation of keratinocyte growth, differentiation, and vitamin D metabolism by analogs of 1,25-dihydroxyvitamin D. J Invest Dermatol. 1993;101(5):713–718. doi:10.1111/1523-1747.ep12371681
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