Evaluation of lipid profile in young adults (18-50 years) with psoriasis vulgaris in Chennai

Introduction

Psoriasis is a long-term inflammatory condition that can significantly affect an individual's quality of life in milder cases and lead to potential cardiovascular abnormalities in more severe cases.^[1] In the United States, around 2% of the population has psoriasis, while in India, the prevalence ranges from 0.8% to 5.6%. The onset of psoriasis typically occurs in the second decade of life without a specific gender preference. It is often linked with metabolic syndrome, a cluster of cardiovascular risk factors such as central obesity, high blood pressure, abnormal lipid levels, and glucose intolerance.^[1]

Several factors contribute to the association between psoriasis and lipid abnormalities. Chronic inflammation plays a key role, as inflammatory molecules like TNF-alpha and IL-1, IL-6 not only contribute to skin changes in psoriasis but also affect insulin function, lipid metabolism, and fat cell profiling.^[1] Genetic factors also play a role, with certain genes like PSORS2, PSORS3, PSORS4, CDKALI, and Apo E4 being linked to both psoriasis and metabolic syndrome. ^[2] Additionally, lifestyle factors such as physical inactivity, smoking, stress, and obesity are implicated in worsening both conditions.^[3]

It's crucial to note that severe psoriasis carries a higher risk of mortality, potentially leading to premature death within 50 years. Obesity is a significant risk factor for developing psoriasis in about 30% of cases, and metabolic disorders can exacerbate the severity of psoriasis symptoms. Therefore, regular screening and evaluation of lipid profile in psoriasis patients is essential as part of routine medical care. Early detection and management of cardiovascular risk factors can help improve outcomes and reduce the impact of these co-existing conditions.^[4], ^[5]

Research into lipid metabolism in psoriasis began in the early 20th century with the quantitative analysis of serum cholesterol levels in psoriatic patients.^[6] Abnormalities in fat metabolism were considered significant factors in the development of psoriasis. Grütz and Burger investigated the progression of psoriatic skin manifestations, likening them to symptoms seen in xanthomatosis.^[7], ^[8], ^[9] Melczer observed changes in phospholipid composition in psoriatic lesions and proposed that inflammation, congestion, and parakeratosis resulted from lipid accumulation in the reticuloendothelial system. It was also suggested that the continual shedding of psoriatic scales led to a permanent loss of lipids, potentially contributing to abnormalities in serum lipid levels. Lipid metabolism is a complex process occurring in various human organs and peripheral blood.^[10], ^[11], ^[12] Further studies are needed to fully understand the disturbances in lipid metabolism in psoriasis. ^[13], ^[14]

Presently, research is focused on various aspects of lipid biology in psoriasis, such as skin surface lipids, epidermal lipids (including stratum corneum lipids and epidermal phospholipids), serum lipids, dermal low-density lipoproteins in psoriatic skin, lipid metabolism, oxidative stress, and the relationships between inflammatory markers, lipid levels, and clinical manifestations of the disease. ^[3]

Aims and Objectives

To study the association between psoriasis and lipid derangements.

To compare the severity of psoriasis with the extent of lipid abnormalities.

Materials and Methods

The study received approval from the ethical committee review board. Patients diagnosed with psoriasis and meeting the inclusion criteria were selected from those visiting the Department of Dermatology, Venereology, and Leprosy at Chettinad Hospital & Research Institute in Kelambakkam between November 2022 to November 2023.

Informed consent was obtained from all patients.

Detailed medical history was collected, including disease duration, onset, past history of diabetes/hypertension, and smoking and alcohol use.

Patients' height and weight were measured, and their BMI was calculated using the weight in kilograms divided by the square of height in meters.

Waist circumference was also measured.

Patients underwent laboratory blood tests including fasting lipid profile and liver function tests.

Associated metabolic conditions such as dyslipidemia and obesity were assessed.

The severity and extent of psoriasis were determined using the PASI score.

The severity of psoriasis vulgaris was assessed against the derangements in fasting lipid profile and liver function tests using statistical analysis using ANOVA.

Results

Most common age group affected was between 26 to 35 years. 55% males and 45% females were affected. Amongst the affected patients, 42% were employed, 20% were home-makers and 38% were students. 30% of the study population had history of alcohol consumption whereas 70% of them were non-alcoholic. 22% had positive history for smoking while 78% of them were non-smokers. 35% of patients had family history of Psoriasis vulgaris while the remaining 65% had no significant family history.64% of the study population had normal BMI while 23% were Overweight, 4% were Obese and 9% were Underweight. A PASI Score of 0-10 was observed in 29% of patients, 10-20 was seen in 32% and >20 was seen in 39% of the patients. 27% of the study patients showed Subungual Hyperkeratosis, 38% showed Pitting, 36% had Onycholysis and Oil drop sign was observed in 10% of them. 11% of the study population had a positive history for Diabetes Mellitus.8% of the study population had a positive history for Systemic Hypertension.

NCEP ATP III guidelines was followed for fasting lipid evaluation. 19% cases had elevated triglycerides levels. 65% had elevated HDL cholesterol levels. 33% cases had elevated serum cholesterol levels.45% cases had elevated LDL, 28% had elevated VLDL. 79% had elevated waist circumference. 3% had increased albumin levels, 45% had increased serum globulin levels, 0.8% had increased albumin globulin ratio, 8% had increased total bilirubin levels, 3% had increased direct bilirubin levels, 7% had increased serum AST, 1.5% had increased serum alkaline phosphatase and 8% had increased Gamma glutamyl transferase.

Assessment of statistical significance between PASI and serum lipid parameters and liver function tests.([Table 1])

It is hence noted that the difference between PASI and Cholesterol & Waist circumference was statistically significant with P values showing 0.01 and 0.021 respectively.([Table 2])

Discussion

In this study, the most commonly affected age group was between 26-35 years, representing 41% of cases. In a study conducted by Jayakar Thomas et al. involving 100 patients, the most common age group affected was between 41-50 years, accounting for 26% of patients. Both males and females had nearly equal incidence rates, with males constituting 55% and females 45%. Similar observations were made in a study by Isabela et al., which included 190 patients, with 48.9% men and 51.5% women affected. Another study by Arnon D. Cohen et al. also found equal sex distribution among affected individuals. ^[15]

The majority of patients in our study were non-alcoholic (70%), while alcohol consumption was present in 30%. In a cross-sectional study with 190 psoriasis cases, 55.3% were non-alcoholic, 16.3% had a history of previous alcohol intake, and 28.4% had current alcohol intake, with mild intake in 36 cases, moderate in 18 cases, and no cases with severe consumption. Most patients in our study were non-smokers (78%), with 22% reporting a history of active smoking. Isabela et al. reported a past history of smoking in 30% and a current history in 20.5% of their cases. ^[16]

A family history of psoriasis was present in 35% of our patients. In a study by Kaur et al., a family history was present in only 2% of patients.^[17], ^[18], ^[19], ^[20] Past history of hypertension was present in 8%, while diabetic history was present in 11%. Nail findings were observed in the majority of patients, with onycholysis seen in 36%, subungual hyperkeratosis in 27%, pitting most commonly at 38%, and the oil drop sign least commonly at 10%. Isabela et al. found nail involvement in 62.1% of patients. ^[21]

Psoriasis severity, defined as a PASI score > 20, was present in 39% of our patients, while moderate psoriasis with PASI 10 to 20 was present in 32%, and mild psoriasis with PASI <10 was seen in 29%. In a case-control study, 47% had mild psoriasis and 53% had severe psoriasis. ^[22]

BMI calculations showed that 36% of our patients had a high BMI, 23% were overweight, and 4% were obese. A study by Amon et al. found that 29.4% of psoriasis patients had obesity compared to 23.5% in controls. In a Spanish study, obesity was more common in psoriasis patients than in controls. Isabela et al. observed that 64.3% of patients had a high BMI, with 31.1% being overweight and 33.2% classified as obese. ^[16]

Waist circumference was increased in 79% of our patients, defined as >35 inches (90 cm) in men and >31 inches (80 cm) in females. In a case-control study by Gisondi et al., approximately 57.1% had increased waist circumference compared to controls (47.6%). There was a significant statistical difference noted between psoriasis severity and waist circumference (P=0.021).

There was a statistically significant correlation between psoriasis severity and elevated serum cholesterol (P=0.010). As disease severity increased, total cholesterol levels also increased. However, there was no statistical difference between PASI scores and levels of HDL, triglycerides, LDL, and VLDL. A study by Suleman et al., including 100 patients with psoriasis and 100 without, found that cholesterol and LDL levels were elevated in patients compared to controls (P<0.001), with no significant difference in HDL and VLDL levels. There was also no significant statistical difference noted between PASI scores and liver function tests, including total protein, albumin, globulin, total and direct bilirubin, ALT, AST, ALKP, and GGT. ^[23]

The National Cholesterol Education Program - ATP III criteria were used to evaluate lipid derangements. In our study, 33% had elevated cholesterol values, which also showed a statistically significant difference with PASI score (P=0.010) and increased waist circumference (P=0.021). ^[15]

Conclusion

In our study, we enrolled a total of 130 patients. We found a statistically significant correlation between PASI score and both serum cholesterol (p=0.010) and waist circumference (p=0.021).

Regarding gender distribution, males were more prevalent, accounting for 55% compared to 45% for females. The most affected age group was between 26-35 years, comprising 41% of the cases.

Among the patients, 30% reported a history of alcohol intake, while 22% had a history of smoking. Additionally, 35% had a positive family history of psoriasis.

The most common nail finding was pitting, observed in 38% of patients. Lipid parameters increased with psoriasis severity; according to NCEP ATP III criteria, 19% had elevated triglycerides, 35% had decreased HDL, 33% had elevated cholesterol, 45% had elevated LDL cholesterol, and 28% had elevated VLDL cholesterol.

These findings highlight the increased risk of lipid derangements and subsequent adverse cardiovascular outcomes in psoriasis patients. Therefore, regular screening for comorbidities should be integrated into their routine medical care.

Source of Funding

None.

Conflict of Interest

None.