Patients and Methods
A total of 44 consecutive male and 35 female patients with psoriasis were enrolled. Similar number of non-psoriatic patients i.e. 44 male and 35 female with matching ages were included as controls. All patients aged more than 18 years of either gender and with various grades of severity were included in study. An informed consent was sought from them after due explanation of purpose. The data was entered into a pre-structured standard proforma. The subjects for control group were taken from healthy paramedical staff, volunteers and patients attending skin out patient department for cosmetic problems like acne and pigment disturbances. Patients with all clinical forms of psoriasis such as plaque, hyperkeratotic, palmoplantar, nail, scalp and flexural were included in the study. They were divided into three broad groups according to severity of the disease. Patients with less than 30% body involvement were graded as mild, 30-50% as moderate and those having more than 50% involvement of body surface as severe. Rule of nine was used to determine this percentage. Only patients with mild disease (< 30% body involvement) were included in study. The patients with moderate to severe psoriasis and erythrodermic and pustular forms were not included in study because of systemic involvement in these forms. Other exclusion criteria were: long history of alcohol intake, smoking, hypertension, diabetes, BMI > than 30kg/m2 or with personal or family history of metabolic disease, patients taking drugs known to affect lipid or carbohydrate metabolism such as beta blockers, thiazides, corticosteroids, cyclosporine, retinoids and lipid lowering drugs were also excluded. Similarly female pregnant patients or those taking oral contraceptive for at least 6 months or women in their menopausal stage were excluded from history. After recording bio data (name, age, address, occupation) patients were asked about the age of onset, duration, and evolution of their disease, drug and family history of disease. Questions focused to exclude the conditions mentioned under exclusion criteria were also asked. A detailed physical examination was conducted to note the sites, degree of erythema, thickness of plaques and amount of scaling over plaques. Psoriasis area and Severity Index (PASI score) was generated for each patient to gauge the severity of psoriasis. A thorough systemic examination was conducted every time by the same qualified physician to exclude systemic disease that would act as a confounding variable. After fasting of 14 hours, 5 ml of venous blood was drawn in sterile syringe and submitted to the laboratory for estimation of total cholesterol, low density lipoprotein (LDL) cholesterol, and serum triglyceride levels. These tests were done on SELECTRA XL chemistry analyzer using Spin react kit (made in Spain). Direct method was used for this test as it is more authenticated. Statistical Analysis: The data was analyzed using SPSS software version 11.0. The student t test was applied to compare the means (2- tailed) among continuous parameters at 95% confidence interval. A p value < 0.005 was considered significant.
The study included a total of 158 patients. Among them 79 had psoriasis (44 male and 35 female) and 79 were healthy controls (44 male and 35 female). Their ages ranged from 18 to 68 years with a mean of 37 ± 7.96 years. All had psoriatic lesions that involved less than 30% of body surface. Family history of psoriasis was positive in 10 (6.32%) patients. The majority of patients (n= 134, 84.8%) had plaque type psoriasis, 10 (6%) had in addition scalp and nail involvement, 05 (3.16%) had guttate lesions, 05 (3.16%) palmoplantar lesions while remaining 04 (2.43%) comprised of hyperkeratotic and flexural psoriasis. The duration of disease ranged between 18 months to 10 years with a mean of 4.5±1.89 years. History of seasonal variation of disease was positive in 42
(26.58%) patients. Out of these 28 (66%) noticed exacerbation of disease in winter while 14 (34%) in summer season. In the patient group serum cholesterol, triglycerides and low density lipoprotein cholesterol (LDL-cholesterol) were significantly higher than those in control group. While the difference in means of high density lipoprotein cholesterol (HDL-cholesterol) and very low density lipoprotein cholesterol between two groups was not significant statistically. The results are depicted in Table 1, 2 and 3. Discussion Disorders mediated by Th1 cytokines are associated with an increased risk of atherosclerosis and vascular events; hence, there has been much interest in determining lipid abnormalities and other risk factors for atherosclerosis in psoriatic patients.7 Lea, Cornish and Block were the first to report increased serum lipids in patients with psoriasis about 50 years ago.8 Since then many studies have been done on this subject which consistently report a raised prevalence of lipid abnormalities in psoriasis.9-12 There is increased prevalence of coronary artery disease in our population.13 It is expected to rise further by Th1 mediated diseases like psoriasis. The predisposition to vascular occlusive events in psoriasis and psoriatic arthritis has increased possibly because of raised plasma lipids and other inflammatory mediators.14 Therefore it is prudent to know and prevent these co morbid conditions in psoriasis. This predisposition seems to be related to the severity of psoriasis.15 However the severity of disease was not classified in this study. There are controversial results about serum cholesterol levels in psoriasis; Some reporting high,16 low,17 and some even normal levels.18 In the presented study the cholesterol levels were significantly higher in patients as compared to controls. Similarly LDL-cholesterol levels of psoriasis patients have also been reported to be high,19 or normal20 in various studies. LDL-cholesterol was significantly higher in concentration in patients in this study. A similar controversy also exists regarding levels of serum triglycerides. Normal,21 high and low17 levels have been reported. There was no significant difference of level of triglycerides between two groups in our study. A significant difference in the levels of HDL-cholesterol and VLDL — cholesterol between two groups was not seen in this study. The results match with that done by Piskin S18 and contrast with that by Reyno et al.22 In the presented study, males were found to have greater abnormalities in serum lipids as compared to females. This may be because the majority of female patients were younger as compared to males and had not reached their menopause. The reasons for dyslipidaemia in psoriasis may be multiple. The structural and functional changes in digestive tract,23 immune mechanisms involving IL-624 and tumour necrosis factor, and C-reactive proteins25 and cellular oxidative stress26 may be responsible for altered lipid metabolism. Thus in consensus with previous studies this, study also shows an increased prevalence of lipid abnormalities in psoriasis. This information fact may suggest an increase in the already existing high prevalence of cardiovascular events in our population. Hence, is recommended early screening and treatment of hyperlipidaemia in psoriasis to prevent atherosclerosis and its complications. Though, the study had a small sample size. However it may form a base for a larger future study.
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