Distinguishing features of body mass index and psoriasis in men and women in Japan: A hospital‐based case–control study

Psoriasis is a chronic inflammatory disease and recent studies reported an association between obesity and psoriasis. To further investigate the association between body mass index (BMI) and psoriasis, a hospital‐based retrospective case–control study was conducted in patients at the Department of Dermatology, Fukuoka University Hospital in 1998–2012. BMI values of psoriatic patients were compared with those of controls, who had skin diseases other than psoriasis. A total of 429 psoriatic patients (295 male, 134 female) and 16 028 controls were enrolled. The number of male patients with psoriasis sharply increased in their 30s, peaked in their 50s and remained relatively high through the 60s. The number of female patients showed a gradual increase to their 60s. Mean BMI was higher in psoriatic patients (23.96 ± 4.46) than in controls (22.22 ± 3.98, P < 0.0001). Age‐stratified mean BMI in psoriatic patients was significantly higher at different ages in each sex. The odds ratio for psoriasis was significantly higher in obese patients. Stratified by age, there was a high odds ratio for psoriasis in men in their 40s, 70s and 80s, and in women in their 20s, 30s and 70s. The study suggests that, apart from those with a genetic predisposition, young women are less likely to develop psoriasis unless they have a high BMI, while men are more likely to acquire psoriasis if they have mild obesity in middle or older age. Our data may partially explain the higher male : female ratio (usually 2:1) in Japanese psoriatic patients.     

Association of chronic plaque psoriasis and severe periodontitis: a hospital based case‐control study

Background Both chronic plaque psoriasis and periodontitis have an increasing prevalence worldwide and have been associated with the metabolic syndrome; however limited information is available on their association. Objective To evaluate the possible association of severe periodontitis and chronic plaque psoriasis. Methods This was a hospital based case‐control study. Chronic plaque psoriasis patients and age‐ and gender‐matched controls have been recruited. Baseline demographic data have been recorded. To explore correlations between different dichotomous variables the Sperman Rho correlation coefficient was used. Correlations were further explored non‐parametrically and univariate and multivariate logistic regression was utilized after adjustment for the effect of confounders. Results During the study enrolment period 100 patients with CPP and 100 age‐ and gender‐matched controls were included in this study. Mean age for both groups was 57.2 ± 5.3 years. 43% of patients and controls were males. Significant correlations where noted between psoriasis and 1) periodontitis (rho = 0.219, P = 0.02) and 2) metabolic syndrome (rho = 0.191, P = 0.07) using Spearman’s Rho correlation co‐efficient. Univariate logistic regression reported significant relations between psoriasis and periodontitis (OR = 3.329, 95%CI: 1.513–7.324, P = 0.003) and psoriasis and metabolic syndrome (OR = 2.293, 95%CI: 1.250–4.207, P = 0.007). On the contrary, a non‐significant relation between psoriasis and active smoking status was detected (OR = 1.041, 95%CI: 0.597–1.817, P = 0.887). In a multivariate analysis model we found a significant correlation of psoriasis and periodontitis when controlled for the presence of metabolic syndrome (OR: 2.486, 95%CI: 1.002–5.842, P = 0.049). Conclusion Periodontitis may be associated with psoriasis but further studies are required to elucidate their relationship in the context of the biologic plausibility.     

Psoriasis and hypertension: a case‐control study

Background Several studies stated that patient with psoriasis carried an increased risk of psoriasis but some studies did not demonstrate this association. Objectives The aim of this study was to evaluate the prevalence of hypertension in psoriasis based on a sample of Spanish population. Methods This was a hospital‐based case‐control study involving 661 psoriatic patients (cases) and 661 control matched by gender and age. Meta‐analysis of the previous studies was made. Results The prevalence of hypertension was significantly higher in psoriasis patients than controls (30.3%, 21.3%, respectively, P < 0.001). In a multivariate analysis, hypertension was associated with psoriasis after controlling for age, gender, diabetes, obesity and smoking (OR = 1.44, 95% confidence interval: 1.07–1.94). Conclusion The results of this study support the association between psoriasis and hypertension.     

The effect of overweight and obesity on psoriasis patients in Chinese Han population: a hospital‐based study

Background Accumulating evidence indicates that psoriasis is associated with increased risk of overweight and obesity. However, few studies have investigated this relationship in Chinese Han population. Objective The aim of this study was to explore the relationship between overweight/obesity and psoriasis and to evaluate the overweight/obesity effect on the clinical features of psoriasis in Chinese Han population. Methods A hospital‐based study was conducted, which involved in 4452 patients and 1166 controls of Chinese Han through epidemiological investigation. Controls used in the study were individuals without psoriasis from health examination centre, and other skin disease patients from outpatient department. Results Compared with the control group, a significantly greater prevalence of overweight and obesity was observed in psoriasis patients. The estimated ORs were 1.301 (95% CI, 1.105–1.531) and 1.680 (95% CI, 1.134–2.491) respectively. The disease severity of psoriasis measured by psoriasis area and severity index (PASI) was statistically correlated with body mass index (BMI) (r = 0.184, P < 0.01). Moreover, a high proportion of overweight patients had affected hands or/and feet, buttocks, trunk, legs, arms and arthritis (P < 0.01). Conclusions Our study suggested that psoriatic patients have a higher prevalence of overweight and obesity compared with non‐psoriatic patients in Chinese Han population. Overweight and obesity has different risk effect on severity and manifestations of psoriasis and might be useful for better evaluating psoriasis clinically.     

Possible association of hepatitis C virus infection with late‐onset psoriasis: A hospital‐based observational study

Psoriasis is a chronic inflammatory disease mainly involving the skin and joints, mediated by pro‐inflammatory cytokine tumor necrosis factor (TNF)‐α. In hepatitis C, continuous inflammation mediated by TNF‐α leads to liver cirrhosis and diabetes mellitus. Hence, psoriasis and hepatitis C have pathophysiological factors in common. An epidemiological association between the two conditions has been reported, but no detailed research has yet been performed. Frequency of hepatitis C virus (HCV) infection was assessed in 717 patients with psoriasis and 38 057 with all other dermatological diseases who visited Fukuoka University Hospital in 1998–2011. HCV⁺ and HCV^? psoriatic patients were further compared. Frequency of HCV infection was significantly higher in psoriasis (7.5%) than in controls (3.3%) in overall ages. When stratified by age at the first visit, the frequency was significantly higher in patients with psoriasis than in controls aged in their 60s (11.8% vs 6.6%, respectively, P = 0.0215) and 70s (19.5% vs 7.3%, P < 0.0001). HCV⁺ psoriatic patients were significantly older at onset than HCV^? ones (median, 54 vs 39 years), stronger male predominance (male/female ratio, 4.4:1), similar family history of psoriasis, higher association of diabetes mellitus and hypertension, and significantly lower body mass index (22.4 ± 2.73 vs 24.2 ± 4.61), in age‐stratified (≥40 years) analysis. HCV⁺ psoriatic patients were less obese, but still had a higher frequency of diabetes mellitus and hypertension, possibly due to chronic inflammation in the liver and other organs. HCV infection may trigger psoriasis, especially late‐onset psoriasis, possibly via overproduction of TNF‐α, a common mediator of the two conditions.     

Homocysteine status and cardiovascular risk factors in patients with psoriasis: a case–control study

Background. Psoriasis is a hyperproliferative, cutaneous disorder with the potential to lower levels of folate. This may result in raised levels of homocysteine, an independent risk factor for the development of cardiovascular disease. Objective. A study was conducted to compare levels of red‐cell folate (RCF) and homocysteine in patients with psoriasis and in healthy controls. Levels of homocysteine were also examined in the context of other major cardiovascular risk factors. Methods. In total, 20 patients with psoriasis and 20 controls had their RCF, homo‐cysteine and other conventional cardiovascular risk factors assessed. Results. Patients with psoriasis had a trend towards lower levels of RCF. Significantly raised levels of homocysteine were found in patients with psoriasis compared with controls (P = 0.007). There was no correlation between homocysteine levels, RCF levels or disease activity as measured by the Psoriasis Area and Severity Index. Patients with psoriasis had higher body mass index (P < 0.004) and higher systolic blood pressure (P < 0.001) than controls. This may contribute to the excess cardiovascular mortality observed in patients with psoriasis.     

Pigmented purpura dermatosis and viral hepatitis: a case‐control study

Pigmented purpuric dermatosis (PPD) is characterized by petechial and pigmented macules on the lower limbs. The aetiology of PPD remains obscure. Some reports have suggested an association between PPD and hepatitis B or C infection. This prospective case‐control study was designed to investigate the association of positive hepatitis B or C serology with PPD. A total of 60 PPD patients and 230 randomly selected controls were enrolled. Sera from all patients and controls were tested for liver function tests (LFT), hepatitis B surface antigen (HBS Ag), and hepatitis C virus antibody (HCV Ab). The prevalence of HBS Ag in patients with PPD and the controls was 3 per cent (5/60) and 4.3 per cent (10/230), respectively. The prevalence of HCV Ab was 1.7 per cent (1/60) and 1.3 per cent (3/230) among patients and controls, respectively. No statistically significant difference was noted in the prevalence of positive hepatitis B or C serology (P‐values 0.73 and 0.58, respectively). No statistically significant difference in LFT was observed between the two groups. Therefore, the authors believe it is unlikely that HBV or HCV are directly involved in the pathogenesis of PPD.