SERUM CHOLESTEROL, URIC ACID AND PROTEINS IN PSORIASIS

Hyperuricemia in Psoriatic Arthritis: Epidemiology, Pathophysiology, and Clinical Implications

Psoriatic arthritis (PsA) represents the articular component of the systemic psoriatic disease and the extra-cutaneous disorder most frequently found in patients with psoriasis. Besides the articular involvement, PsA is associated with several metabolic abnormalities such as insulin resistance, hypertension, diabetes and hyperuricemia. Uric acid is the final product of purine metabolism and the etiological substrate of gout. Accumulating evidence highlights the emerging role of hyperuricemia as a major cardiovascular risk factor. Moreover, different studies evaluated the interplay between hyperuricemia and psoriatic disease, suggesting that individuals affected by psoriasis or PsA might present higher serum levels of uric acid and that hyperuricemia might affect severity of clinical manifestations and degree of inflammation in PsA patients. In this review, we focus on the bidirectional relationship between uric acid and PsA, analyzing how uric acid may be involved in the pathogenesis of psoriasis/PsA and how clinical manifestations of PsA and inflammatory mediators are affected by uric acid concentrations. Finally, the effects of anti-rheumatic drugs on uric acid levels and the potential benefit of urate-lowering therapies on psoriasis and PsA were summarized.

Cross-sectional study on the correlation of serum uric acid with disease severity in Korean patients with psoriasis

BACKGROUND

Hyperuricaemia is a common finding in patients with psoriasis. However, previous studies have reported inconsistent results about the association between serum uric acid concentration (SUAC) and psoriasis severity. Recent studies have also reported that SUAC is associated with metabolic dysregulation.

AIM

To assess any association between SUAC and clinical features of psoriasis, and to investigate the characteristics of patients with psoriasis with hyperuricaemia compared with similar patients with normouricaemia.

METHODS

Cross-sectional data from 198 Korean patients with psoriasis who visited our clinic were analysed. Association of SUAC with clinical features of psoriasis, body mass index (BMI) and various laboratory values was assessed in both genders separately.

RESULTS

The average uric acid concentration of patients with psoriasis was not significantly different from that of the healthy population, for both genders (P > 0.05). There was a positive correlation between SUAC and Psoriasis Area and Severity Index (PASI) and BMI in patients with psoriasis (P < 0.05). There was no association with age of disease onset, family history of psoriasis, or other laboratory values (P > 0.05), in either gender. Of the other factors of disease severity, the extent of body surface involvement was correlated with uric acid concentration (P < 0.05) although there was no significant relationship with activity of individual lesions (P > 0.05). Mean PASI and extent of psoriasis were increased in hyperuricaemic compared with normouricaemic patients (P < 0.05).

CONCLUSIONS

SUAC in patients with psoriasis is positively associated with PASI, extent of skin involvement and BMI for both genders independently.

Are lipoprotein profile and lipoprotein (a) levels altered in men with psoriasis?

BACKGROUND

Previous studies have demonstrated that patients with psoriasis may have an increased risk of a variety of noncutaneous diseases, including arterial and venous occlusive diseases. Changes in plasma lipid and lipoprotein composition in patients with psoriasis may be the reason for the increased risk of atherosclerosis in these patients. Lipoprotein (a) (Lp(a)) is a genetically determined lipoprotein associated with an increased prevalence of atherosclerotic and thrombotic cardiovascular diseases.

OBJECTIVE

The aim of this prospective study was to determine the lipid profile and to define the significance of Lp(a) levels in men with psoriasis. The other purpose was to learn whether a correlation exists between psoriasis area and severity index score and serum Lp(a) or other lipids.

METHODS

Serum Lp(a) levels were measured with a commercially available noncompetitive enzyme-linked immunosorbent assay in 32 men with psoriasis and in 13 healthy men. Total serum cholesterol, triglyceride, high-density lipoprotein, low-density lipoprotein, apolipoprotein A-I and apolipoprotein B levels, and atherosclerotic risk factors other than hyperlipidemia were determined. Secondary hyperlipidemia from various diseases and drugs was ruled out in both groups.

RESULTS

Serum Lp(a) levels were higher in men with psoriasis than in healthy male subjects, but the difference was not significant (p = 0.063). Serum fasting glucose levels were also found to be higher in the psoriasis group (p < 0.05). Higher serum Lp(a) and fasting glucose levels tended to occur in patients with extensive and severe skin involvement. No statistical differences were observed in the total cholesterol, triglyceride, high-density lipoprotein, low-density lipoprotein, apolipoprotein A-I, and apolipoprotein B levels between the two groups (p > 0.05).

CONCLUSION

Our results suggest that the increased Lp(a) level might be a factor involved in occlusive vascular disorders in patients with psoriasis and that patients with extensive and severe skin involvement are more predisposed to relatively high Lp(a) levels.

Serum uric acid levels in psoriatic arthritis

Serum uric acid levels were determined in patients with psoriatic arthritis on and off medication, with rheumatoid arthritis on no medication likely to alter serum values, and in patients with uncomplicated psoriasis. Values in males were higher than those in females. A larger prevalence of values above the normal range were seen in males with psoriatic arthritis on uncontrolled medication (13-5%) and in males with rheumatoid arthritis (12%) than in the other groups. The means for both these groups were around the midpoints of the normal range. These findings suggest that hyperuricaemia is not a common characteristic of psoriatic arthritis.