Comment on acne and glycemic index

Assessment of ADMA, IMA, and Vitamin A and E Levels in Patients with Acne Vulgaris

BACKGROUND

Acne vulgaris is a common skin disease in adolescents known to be associated with oxidative stress. However, the number of studies in which oxidative stress and antioxidants are evaluated together is limited.

AIMS

In this study, we aimed to investigate L-arginine/nitric oxide (NO) pathway metabolites, ischemia-modified albumin (IMA), and vitamin A and E levels in patients with acne and its association with disease severity.

PATIENTS/METHODS

Ninety patients with acne and 30 healthy adults were included in the study. The serum levels ofL-arjinin, L-arginine metabolites, IMA, and vitamins A and E measured in the patient and control groups.

RESULTS

Asymmetric dimethylarginine (ADMA), LN^G -monomethyl-L-arginine (L-NMMA) and symmetric dimethylarginine (SDMA), and IMA levels were significantly higher in the patients with acne than in the control group (P ˂ .05). The L-arginine/ADMA ratio and citrulline and vitamin A levels were significantly lower in patients with acne than those of the controls (P ˂ .05). ADMA and IMA plasma levels were increased in parallel with the disease severity (P ˂ .05). L-arginine/ADMA ratio, L-arginine, citrulline, and vitamin A plasma levels decreased as the disease became severe (P ˂ .05). Although L-arginine and vitamin E levels were lower in the patient group compared to the control group, the difference was not statistically significant (P ˃ .05).

CONCLUSION

These results suggest that IMA and L-arginine-NO pathway associated with ischemia and oxidative stress may play an important role in the pathogenesis and progression of acne vulgaris.

Insulin resistance in severe acne vulgaris

Introduction

Acne vulgaris is a pilosebaceous gland disease that usually affects people from puberty to young adulthood. It is seen especially on the face, neck, trunk and arms. Its severity differs from patient to patient and its pathogenesis is multifactorial. The main pathogenic factors of acne are high sebaceous gland secretion, follicular hyperproliferation, high androgen effects, propionibacterium acnes colonization and inflammation. Diet is always thought a probable reason for acne and many studies are done about acne and diet.

Aim

To determine the effect of insulin resistance in severe acne vulgaris.

Material and methods

Two hundred and forty-three acne vulgaris patients and 156 healthy controls were enrolled into the study. The blood levels of insulin and glucose were measured. Homeostasis Model Assessment (HOMA) Index was calculated. The values were compared with the control group.

Results

All of the patients were in the severe acne group according to their scores on the global acne scoring scale. While fasting blood glucose levels were not different between the groups (p > 0.05, 82.91 ±9.76 vs. 80.26 ±8.33), the fasting insulin levels were significantly higher in the patient group than in the control group (p < 0.001, 14.01 ±11.94 vs. 9.12 ±3.53). Additionally, there was a highly significant difference between the patient and control groups in terms of HOMA values (p < 0.001, 2.87 ±2.56 vs. 1.63 ±0.65).

Conclusions

These results suggest that insulin resistance may have a role in the pathogenesis of acne.

Antimicrobial Investigation of Linum usitatissimum for the Treatment of Acne

Light petroleum, dichloromethane and methanolic extracts of Linum usitatissimum were investigated using GC/MS. The main components of three sequential extracts were methyl linolenate (11.9-33.9%) and methyl linoleate (3.4-9.1%). Components possessing antimicrobial activity against acne causing bacteria, namely α-linolenic acid (7.0 -7.1%), α-terpinene (1.7-3.1%), terpinen-4-ol (1.3-4.6%), 4-cymene (1.6-7.1%) and α-pinene (1.1%), were found in varying amounts. Antimicrobial screening indicated that the light petroleum extract was more active against aerobic and anaerobic test strains with a MIC value of 1.25 mg/mL and a MBC of 2.5 mg/mL against S. aureus and P. acnes. A MIC of 2.5 mg/mL was observed against S. epidermidis.

Acne e dieta: verdade ou mito?

Nos últimos 50 anos, foram publicados inúmeros estudos com a finalidade de comprovar se a dieta está relacionada à etiologia da acne. Embora existam estudos antigos, que são bem difundidos entre os dermatologistas e negam a associação entre acne e dieta, seu delineamento científico é pobre. Recentemente, novos artigos demonstraram evidências contrárias às publicações anteriores. Sendo assim, os autores realizaram esta revisão bibliográfica com o intuito de averiguar se a dieta influencia direta ou indiretamente um ou mais dos quatro pilares etiopatogênicos fundamentais da acne: (1) hiperproliferação dos queratinócitos basais, (2) aumento da produção sebácea, (3) colonização pelo Propionibacterium acnes e (4) inflamação.

Diet and acne

Historically, the relationship between diet and acne has been highly controversial. Before the 1960s, certain foods were thought to exacerbate acne. However, subsequent studies dispelled these alleged associations as myth for almost half a century. Several studies during the last decade have prompted dermatologists to revisit the potential link between diet and acne. This article critically reviews the literature and discusses how dermatologists might address diet when counseling patients with acne. Dermatologists can no longer dismiss the association between diet and acne. Compelling evidence exists that high glycemic load diets may exacerbate acne. Dairy ingestion appears to be weakly associated with acne, and the roles of omega-3 fatty acids, antioxidants, zinc, vitamin A, and dietary fiber remain to be elucidated. This study was limited by the lack of randomized controlled trials in the literature. We hope that this review will encourage others to explore the effects of diet on acne.

New developments in our understanding of acne pathogenesis and treatment

Interest in sebaceous gland physiology and its diseases is rapidly increasing. We provide a summarized update of the current knowledge of the pathobiology of acne vulgaris and new treatment concepts that have emerged in the last 3 years (2005-2008). We have tried to answer questions arising from the exploration of sebaceous gland biology, hormonal factors, hyperkeratinization, role of bacteria, sebum, nutrition, cytokines and toll-like receptors (TLRs). Sebaceous glands play an important role as active participants in the innate immunity of the skin. They produce neuropeptides, excrete antimicrobial peptides and exhibit characteristics of stem cells. Androgens affect sebocytes and infundibular keratinocytes in a complex manner influencing cellular differentiation, proliferation, lipogenesis and comedogenesis. Retention hyperkeratosis in closed comedones and inflammatory papules is attributable to a disorder of terminal keratinocyte differentiation. Propionibacterium acnes, by acting on TLR-2, may stimulate the secretion of cytokines, such as interleukin (IL)-6 and IL-8 by follicular keratinocytes and IL-8 and -12 in macrophages, giving rise to inflammation. Certain P. acnes species may induce an immunological reaction by stimulating the production of sebocyte and keratinocyte antimicrobial peptides, which play an important role in the innate immunity of the follicle. Qualitative changes of sebum lipids induce alteration of keratinocyte differentiation and induce IL-1 secretion, contributing to the development of follicular hyperkeratosis. High glycemic load food and milk may induce increased tissue levels of 5alpha-dihydrotestosterone. These new aspects of acne pathogenesis lead to the considerations of possible customized therapeutic regimens. Current research is expected to lead to innovative treatments in the near future.

Can we define acne as a chronic disease? If so, how and when?

There is widespread misunderstanding of acne amongst both the medical and lay community, who often perceive the condition to be a simple, self-limited affliction of adolescents. Because many think that the disease "will go away on its own," they do not feel an urgency to aggressively treat acne. However, very often the reality is that acne treatment can be quite difficult. Furthermore, acne can be a devastating disease for the patient, since it manifests on visible body parts and in children near puberty, who are vulnerable both socially and psychologically. Most typically, acne is not an acute disease but rather a condition that continuously changes in its distribution and severity. Usually, acne treatment is necessary for many months and sometimes years. Despite treatment, acne may cause scarring and associated negative psychological effects. It is important for both patients and physicians to be aware that very effective treatments are available. It is also important to realize that new studies have proven the benefit of maintenance therapy with topical retinoids; these agents can minimize the potential for relapse, which is part of the natural history of acne. This article reviews the evidence suggesting that acne is a chronic disease in at least a subset of individuals. The members of the Global Alliance to Improve Outcomes in Acne believe that acne should be recognized and investigated as a chronic disease. This will change expectations of clinical trial design and treatment and will highlight gaps in the knowledge of acne epidemiology. The result should be an improvement in patient outcomes.