Adipokines and psoriasis

Increased plasma resistin and decreased omentin levels in Japanese patients with psoriasis

Psoriasis is associated with obesity accompanied by insulin resistance. A recent study disclosed increased plasma resistin and decreased plasma omentin levels in obesity. Few studies of plasma levels of resistin and omentin are available in psoriasis. We analyzed plasma levels of resistin and omentin in psoriasis and compared them with those of healthy controls. Evaluation of plasma levels of resistin and omentin was performed by enzyme-linked immunosorbent assay (ELISA) for 62 psoriasis patients and 58 healthy controls. The severity of psoriasis was evaluated by psoriasis area and severity index (PASI) score. Plasma levels of resistin were significantly increased in psoriasis as compared with those of healthy controls. In contrast, plasma levels of omentin were significantly decreased in psoriasis patients. Plasma levels of resistin and omentin were positively and negatively correlated with PASI scores, respectively. After the treatment of psoriasis, resistin levels were decreased and omentin levels were increased, respectively, compared with those of pretreated. Plasma levels of resistin and omentin might be useful for evaluating the disease activity of psoriasis.

Circulating levels of lipocalin-2 and retinol-binding protein-4 are increased in psoriatic patients and correlated with baseline PASI

Psoriasis has been related to metabolic syndrome (MS). Adipocytokines produced by white adipose tissue may be involved in the pathogenesis of psoriasis and its association with MS. Our objectives were to characterize the profile of a number of different inflammatory and atherogenic markers, vitamins, adipokines and cytokines and their potential involvement in MS in patients with moderate-to-severe psoriasis without joint involvement compared to anthropometrically matched controls, and to evaluate correlation with severity of the skin disease and changes after narrow-band UVB (NB-UVB) phototherapy. We designed a prospective cross-sectional study. Baseline waist circumference, body fat composition, lipid, carbohydrate and calcium metabolism profile, inflammation markers, homocysteine and vitamins D, B6, B12 and folic acid, leptin, resistin, omentin, lipocalin-2, adipocyte fatty acid-binding protein, retinol-binding protein-4 (RBP-4), interleukin-6, soluble tumour necrosis factor receptor 1 (sTNFR1) and interleukin-17 of 50 psoriasis patients and 50 gender, age and body mass index-matched controls were recorded, then evaluated after NB-UVB in the patients. The patients had higher baseline serum concentrations of leptin, RBP-4, lipocalin-2 and sTNFR1. Baseline psoriasis area and severity index correlated with serum concentrations of RBP-4 and lipocalin-2 only. Principal components analysis disclosed a component including vitamins B12, B6, folic acid, calcidiol and HDL-cholesterol that was only present in healthy controls and opposed to a cluster of variables which promote MS. This component was absent in the patients. Our results point to lipocalin-2 and RBP-4 as relevant mediators of the trend towards MS in psoriatic patients.

Obesity and psoriasis: inflammatory nature of obesity, relationship between psoriasis and obesity, and therapeutic implications

Obesity, particularly abdominal obesity, is currently considered a chronic low-grade inflammatory condition that plays an active role in the development of the pathophysiologic phenomena responsible for metabolic syndrome and cardiovascular disease through the secretion of proinflammatory adipokines and cytokines. In recent years clear genetic, pathogenic, and epidemiologic links have been established between psoriasis and obesity, with important implications for health. The relationship between the 2 conditions is probably bidirectional, with obesity predisposing to psoriasis and psoriasis favoring obesity. Obesity also has important implications in the treatment of psoriasis, such as a greater risk of adverse effects with conventional systemic drugs and reduced efficacy and/or increased cost with biologic agents, for which dosage should be adjusted to the patient's weight.

Effect of narrowband ultraviolet B therapy on inflammatory markers and body fat composition in moderate to severe psoriasis

BACKGROUND

Previous studies have shown increased prevalence of metabolic syndrome in patients with psoriasis.

OBJECTIVES

To characterize the anthropometric and metabolic profile of Spanish patients with moderate to severe psoriasis compared with controls without psoriasis matched for gender, age and body mass index (BMI), and to evaluate the impact of narrowband ultraviolet B (NB-UVB) therapy on patient profiles.

METHODS

Baseline waist circumference, body fat composition, lipid, carbohydrate and calcium metabolism profile, inflammation markers, homocysteine, vitamins D, B(6) and B(12) and folic acid of 50 patients with psoriasis and 50 matched controls were recorded then evaluated after NB-UVB in patients with psoriasis and correlated with clinical outcome.

RESULTS

Despite very similar BMIs, 54% of patients met International Diabetes Foundation criteria for metabolic syndrome compared with 42% of controls (P = 0·01); body fat was 29·9% in patients and 28·0% in controls (P = 0·037), correlating with waist circumference; while patient atherogenic profiles were less favourable, with higher apolipoprotein B and low density lipoprotein cholesterol than controls, and both patients and controls showed insufficient vitamin D serum levels (< 20 ng mL(-1)). Mean improvement of Psoriasis Area and Severity Index (PASI) after NB-UVB was 78·2%. Ferritin, B(12) and C-reactive protein decreased significantly after NB-UVB therapy. Vitamin D levels reached adequate levels after phototherapy; however, no relationship with PASI improvement was observed.

CONCLUSIONS

We characterized inflammatory and atherogenic profiles of Spanish patients with psoriasis compared with matched controls. After NB-UVB therapy we demonstrated improvement in psoriasis and some systemic inflammation markers, which were not mediated by enhancement of vitamin D synthesis.

Serum levels of visfatin and omentin-1 in patients with psoriasis and their relation to disease severity

BACKGROUND

The association of the novel adipokines visfatin and omentin-1 with psoriasis is still obscure. Data concerning other inflammatory diseases suggest a possible role of these adipokines in the pathophysiology of psoriasis.

OBJECTIVES

To investigate serum levels of visfatin and omentin-1 in patients with psoriasis compared with healthy controls, and to consider their relation to disease duration, disease severity and obesity markers.

METHODS

Visfatin and omentin-1 concentrations were measured in 46 patients with plaque-type psoriasis and 42 healthy controls by using specific enzyme-linked immunosorbent assays.

RESULTS

Patients with psoriasis showed considerably higher serum levels of visfatin than healthy controls with significant positive correlation with disease severity and duration. They also showed lower levels of ominten-1 compared with healthy controls with significant inverse correlation with body mass index and waist circumference.

CONCLUSIONS

Coordinated roles for visfatin and omentin-1 are suggested in the modulation of the inflammatory environment in patients with psoriasis. Given the significant relations of omentin-1 with obesity markers, the health consequences of excessive weight should be better communicated to patients with psoriasis.

Obesity and risk of incident psoriatic arthritis in US women

OBJECTIVES

Both overall and central obesity have been associated with the risk of psoriasis in a prospective study. Data on the association between obesity and psoriatic arthritis (PsA) have been sparse and no evidence on obesity measures and the risk of incident PsA is available now. This study aimed to evaluate the association between obesity and the risk of incident PsA in a large cohort of women.

METHODS

89,049 participants were included from the Nurses Health Study II over a 14-year period (1991-2005). Information on body mass index (BMI), weight change and measures of central obesity (waist circumference, hip circumference and waist-hip ratio) was collected during the follow-up. The incidence of clinician-diagnosed PsA was ascertained and confirmed by supplementary questionnaires.

RESULTS

146 incident PsA cases were identified during 1,231,693 person-years of follow-up. Among all participants, BMI was monotonically associated with an increased risk of incident PsA. Compared with BMI less than 25.0, the RR was 1.83 for BMI 25.0-29.9 (95% CI 1.15 to 2.89), 3.12 for BMI 30.0-34.9 (95% CI 1.90 to 5.11) and 6.46 for BMI over 35.0 (95% CI 4.11 to 10.16). There was a graded positive association between weight change from age 18 years, measures of central obesity and risk of PsA (p for trend <0.001). The analysis among participants developing psoriasis during follow-up revealed a similar association (p for trend <0.01), indicating an increased risk of PsA associated with obesity among patients with psoriasis.

CONCLUSION

This study provides further evidence linking obesity with the risk of incident PsA among US women.

Leptin, adiponectin, visfatin and retinol-binding protein-4 - mediators of comorbidities in patients with psoriasis?

White adipose tissue is known to be involved in numerous physiological processes such as insulin-mediated functions, lipid and glucose metabolism, vascular changes and coagulation. These processes are mainly mediated by adipokines that are secreted either from adipocytes or cells of the stromal-vascular fraction of adipose tissue. In obesity, a shift in the production of adipokines can mediate the development of associated diseases, such as metabolic syndrome, and vascular complications, such as artherosclerosis, myocardial infarction or stroke, which are known comorbidities of psoriasis too. As obesity is a frequently seen comorbidity in psoriasis patients, adipokines could be involved in the pathogenesis of psoriasis and/or its comorbidities either dependently or independently from obesity. Therefore, this study investigates the levels of four major adipokines in psoriasis patients compared with a control group of healthy volunteers without chronic inflammatory diseases in relation to body composition. Leptin, adiponectin (high molecular weight (HMW) and total adiponectin), visfatin and retinol-binding protein 4 (RBP4) have been analysed in 79 psoriasis patients and in 80 healthy volunteers. It was shown that HMW adiponectin (OR 1.3755; P = 0.0094) and visfatin (OR 1.1267; P = 0.0472) are independently increased, and RBP4 (OR 0.9884; P < 0.0001) is independently decreased in psoriasis. In conclusion, increased levels of HMW adiponectin and decreased levels of RBP4 could be a mechanism in a chronic inflammatory state that helps to protect against vascular and metabolic disorders, whereas the increase of the pro-inflammatory adipokine visfatin could lead to atherosclerosis and vascular disorders found in psoriasis.

Kinetics of circulating Th17 cytokines and adipokines in psoriasis patients

Psoriasis is associated with an increase of Th17 cytokines, such as IL-17, IL-22, IL-21, and TNF-α, which are produced by Th17 cells. Adipokines are peptide hormones or cytokines secreted from adipose tissues and involved in the pathogenesis of metabolic syndrome (MS). Psoriasis patients have a high prevalence of the MS. In this study, we investigated the statistics of circulating Th17-related cytokines and adipokines in psoriasis patients. Our study identified the significant elevation of serum IL-6, IL-21, IL-22, and resistin levels in psoriasis patients. Increased serum levels of IL-22 and adiponectin were positively correlated with Psoriasis Area and Severity Index (PASI). In contrast, serum high molecular weight adiponectin levels were decreased in psoriasis and negatively correlated with PASI.