Diabetes mellitus and skin diseases in childhood

The Prevalence of Vitiligo: A Meta-Analysis

Objective

To conduct a meta-analysis assessing the prevalence of vitiligo.

Methods

Literatures that reported prevalence rates of vitiligo were identified using EMBASE, PubMed, the Cochrane Library, China National Knowledge Infrastructure (CNKI), Wanfang database and Weipu database for the period from inception to May 2016. We performed stratified analyses on possible sources of bias, including areas difference, years of publication, gender and age. Publication bias was assessed with Egger’s test method.

Results

A total of 103 studies were eligible for inclusion. The pooled prevalence of vitiligo from 82 population- or community-based studies was 0.2% (95%CI: 0.1%–0.2%) and from 22 hospital-based studies was 1.8% (95%CI: 1.4%–2.1%). A relatively high prevalence of vitiligo was found in Africa area and in female patients. For population- or community-based studies, the prevalence has maintained at a low level in recent 20 years and it has increased with age gradually. For hospital-based studies, the prevalence has showed a decreased trend from 60s till now or from young to old. No significant publication bias existed in hospital-based studies (t = 0.47, P = 0.643), while a significant publication bias existed in population- or community-based studies (t = 2.31, P = 0.026).

Conclusion

A relatively high prevalence of vitiligo was found in Africa area and in female patients. The prevalence has maintained at a low level in recent years. It showed an inverse trend with age increment in population- or community-based studies and hospital-based studies.

Increased prevalence of the metabolic syndrome in patients with moderate to severe psoriasis

The role of chronic inflammation causing metabolic and vascular disorders is increasingly recognized. It is hypothesized that proinflammatory cytokines contribute to atherogenesis, peripheral insulin resistance, and the development of hypertension and type II diabetes. Psoriasis as a chronic inflammatory skin disorder is characterized by a variety of immunologic and inflammatory changes and may similarly predispose for those disorders. The objective of this study was to elucidate the association of psoriasis with chronic vascular and metabolic disorders. We investigated a total of 581 adult patients hospitalised for plaque type psoriasis as compared to 1,044 hospital-based controls. A distinct pattern of chronic disorders was found to be significantly associated with psoriasis, including diabetes mellitus type II [odds ratio (OR)=2.48], arterial hypertension (OR = 3.27), hyperlipidemia (OR = 2.09), and coronary heart disease (OR = 1.95). The combined presence of these conditions together with obesity, known as the metabolic syndrome, was clearly more prevalent in psoriasis patients (OR = 5.29). In addition, psoriasis patients were significantly more likely to be smokers (OR = 2.96) and to have a regular or heavy consumption of alcohol (OR = 3.33 and 3.61, respectively). In conclusion, psoriasis patients appear to be at higher risk for diabetes mellitus and cardiovascular disease. This could likely be due to the effects of chronic inflammatory changes, in particular the secretion of proinflammatory cytokines. The risk of late term cardiovascular complications might support the use of systemic treatment in psoriasis.

Repression of insulin gene expression by adenovirus type 5 E1a proteins

Insulin gene transcription relies on enhancer and promoter elements which are active in pancreatic beta cells. We showed that adenovirus type 5 infection of HIT T-15 cells, a transformed hamster beta cell line, represses insulin gene transcription and mRNA levels. Using expression plasmids transiently introduced into HIT T-15 cells, we showed that adenovirus type 5 E1a transcription regulatory proteins repress insulin enhancer-promoter element activity as assayed with a surrogate xanthine-guanine phosphoribosyltransferase gene. We relate E1a repression of the insulin gene to other examples of repression of enhancer-dependent genes by E1a and discuss the possible relationship of this repression to insulin gene regulation.

Repression of insulin gene expression by adenovirus type 5 E1a proteins

Insulin gene transcription relies on enhancer and promoter elements which are active in pancreatic beta cells. We showed that adenovirus type 5 infection of HIT T-15 cells, a transformed hamster beta cell line, represses insulin gene transcription and mRNA levels. Using expression plasmids transiently introduced into HIT T-15 cells, we showed that adenovirus type 5 E1a transcription regulatory proteins repress insulin enhancer-promoter element activity as assayed with a surrogate xanthine-guanine phosphoribosyltransferase gene. We relate E1a repression of the insulin gene to other examples of repression of enhancer-dependent genes by E1a and discuss the possible relationship of this repression to insulin gene regulation.