Patients with alopecia areata show signs of insulin resistance

Deciphering the Complex Immunopathogenesis of Alopecia Areata

Alopecia areata (AA) is an autoimmune-mediated disorder in which the proximal hair follicle (HF) attack results in non-scarring partial to total scalp or body hair loss. Despite the growing knowledge about AA, its exact cause still needs to be understood. However, immunity and genetic factors are affirmed to be critical in AA development. While the genome-wide association studies proved the innate and acquired immunity involvement, AA mouse models implicated the IFN-γ- and cytotoxic CD8+ T-cell-mediated immune response as the main drivers of disease pathogenesis. The AA hair loss is caused by T-cell-mediated inflammation in the HF area, disturbing its function and disrupting the hair growth cycle without destroying the follicle. Thus, the loss of HF immune privilege, autoimmune HF destruction mediated by cytotoxic mechanisms, and the upregulation of inflammatory pathways play a crucial role. AA is associated with concurrent systemic and autoimmune disorders such as atopic dermatitis, vitiligo, psoriasis, and thyroiditis. Likewise, the patient's quality of life (QoL) is significantly impaired by morphologic disfigurement caused by the illness. The patients experience a negative impact on psychological well-being and self-esteem and may be more likely to suffer from psychiatric comorbidities. This manuscript aims to present the latest knowledge on the pathogenesis of AA, which involves genetic, epigenetic, immunological, and environmental factors, with a particular emphasis on immunopathogenesis.

Alopecia areata: What's new in the epidemiology, comorbidities, and pathogenesis?

BACKGROUND

Alopecia areata (AA) is a common, acquired, and nonscarring type of hair loss that affects people of every generation and is intractable in severe and relapsing cases. Patients with AA, especially those with greater scalp involvement, have poor health-related quality-of-life scores.

PURPOSE

Following our previous review article in the April 2017 issue of the Journal of Dermatological Science, we aim to provide a pair of review articles on recent progress in multidisciplinary approaches to AA.

MAIN FINDINGS

We found more than 1800 publications on AA from July 2016 to December 2022.

CONCLUSIONS

In this review, we focused on the latest information on the epidemiology, comorbidities, and pathogenesis of AA.

Is the severity of alopecia areata associated with arterial stiffness?

Background

This study aimed to evaluate the severity of alopecia areata (AA) associations with metabolic syndrome, body composition evaluated by bioimpedance techniques, and arterial stiffness based on pulse-wave velocity analysis.

Materials and Methods

This cross-sectional study was conducted on patients referred to AA Clinic at Razi Hospital in 2021 and 2022. Patients with AA with the Severity of Alopecia Tool (SALT) score above 20% and receiving no systemic therapy were included. Patient demographic and clinical information, symptoms of metabolic syndrome, and bioimpedance factors were collected, and the relationship between disease severity, metabolic syndrome, and bioimpedance indicators was evaluated.

Results

In this study, 59 patients were examined, with 26 (44.07%) being female and 33 (55.93%) being male. The mean age of the patients was 37.42 years (standard deviation [SD] =11.28). The severity of the disease was assessed using the SALT score, with the mean severity in terms of the percentage being 69.83% (SD = 28.57%). In the regression model, SALT score was independently related to the severity of vascular stiffness after adjusting for the effect of other variables (beta = 0.033, 95% CI = 0.009-0.057, P = 0.046). Moreover, SALT score was significantly related to metabolic syndrome after adjusting for the effect of other variables (OR = 1.035, 95% CI = 1.012-1.059, P = 0.002).

Conclusion

This study found that AA severity is associated with a higher chance of having metabolic syndrome and arterial stiffness which may lead to cardiovascular diseases in patients with AA, and screening patients regarding cardiometabolic diseases is mandated.

The frequency of fatty liver in patients with alopecia areata: A case-control study

BACKGROUND

Alopecia areata (AA) is an immune-mediated nonscarring hair loss disorder with multiple subtypes, including alopecia universalis (AU). Previous studies have shown a link between serum lipid profile and alopecia. We aimed to investigate the frequency of fatty liver in patients with AU and patchy alopecia areata (PAA) compared to a control group.

METHODS

This case-control study included patients with AU and PAA referred to a dermatology clinic from September 23, 2019 to September 23, 2020. A group of individuals without hair loss disorders attending the same clinic were selected as controls. Participants' general information, including age, sex, weight, height, and waist circumference (WC), was recorded. Body mass index (BMI) was calculated for all participants. Also, hyperlipidemia and statin use were noted and liver enzymes were evaluated. For AU and PAA patients, disease duration and the Severity of Alopecia Tool (SALT) score were also recorded. Then, all subjects underwent ultrasound to assess fatty liver and its grade.

RESULTS

Overall, 32 patients were included in each group. All three groups were comparable in age, sex, weight, height, BMI, WC, hyperlipidemia, abnormal liver enzymes, and statin use. Disease duration and SALT score were significantly higher in the AU than in the PAA group (p = 0.009 and p < 0.001, respectively). The frequency of fatty liver was the highest in AU patients (40.6%), followed by 34.4% in PAA patients, and 21.9% in controls (p = 0.263). This was also the case for grade-1 fatty liver, while grade-2 was more common in PAA patients, and grade-3 was only observed in one patient from the AU group (p = 0.496).

CONCLUSIONS

Fatty liver was more frequent in AU and PAA patients than controls, without statistically significant differences. There might be an association between fatty liver and AA, particularly the AU subtype.

Lipocalin-2 and insulin as new biomarkers of alopecia areata

Lipocalin-2 and visfatin are proinflammatory adipokines involved in the regulation of glucose homeostasis. Their role has been described in numerous inflammatory skin diseases such as atopic dermatitis and psoriasis. Recently, an increased prevalence of metabolic abnormalities has been reported in patients with alopecia areata. The aim of the study is to determine the serum levels of lipocalin-2 and visfatin in patients with alopecia areata in comparison with healthy controls. Moreover, the serum levels of total cholesterol, low-density lipoprotein cholesterol (LDL-cholesterol), high-density lipoprotein cholesterol (HDL-cholesterol), triglycerides, fasting glucose, insulin, c-peptide, and homeostasis model assessment for insulin resistance (HOMA-IR) were evaluated. Fifty-two patients with alopecia areata and 17 control subjects were enrolled in the study. The serum levels of lipocalin-2 [mean ± standard deviation, SD: 224.55 ± 53.58 ng/ml vs. 188.64 ± 44.75, p = 0.01], insulin [median (interquartile range, IQR): 6.85 (4.7–9.8) μIU/ml vs. 4.5 (3.5–6.6), p<0.05], c-peptide [median (IQR): 1.63 (1.23–2.36) ng/ml vs. 1.37 (1.1–1.58), p<0.05)], and HOMA-IR [median (IQR): 1.44 (0.98–2.15) vs. 0.92 (0.79–1.44), p<0.05) were significantly higher in patients with alopecia areata compared to the controls. The serum concentration of insulin and HOMA-IR correlated with the number of hair loss episodes (r = 0.300, p<0.05 and r = 0.322, p<0.05, respectively). Moreover, a positive correlation occurred between insulin, HOMA-IR, c-peptide and BMI (r = 0.436, p <0.05; r = 0.384, p<0.05 and r = 0.450, p<0.05, respectively). In conclusion, lipocalin-2 and insulin may serve as biomarkers for alopecia areata. Further studies are needed to evaluate the role of insulin as a prognostic factor in alopecia areata.

Current controversies in trichology: a European expert consensus statement

INTRODUCTION

Hair disorders are one of the most common conditions within dermatology practice but, although new diagnostic tools and therapeutic options have arisen, the management of these patients still represents a major clinical challenge.

OBJECTIVE

This study aimed at gathering information and achieving consensus on relevant recommendations on the latest advances in alopecia, trichoscopy and hair dermocosmetics.

METHODS

Experts of the steering committee consulted the available evidence on trichology-related areas from the past 5 years and formulated recommendations based on the evidence and their experience. A modified two-round Delphi procedure was performed among 45 European dermatologists experts in trichology to consult their degree of agreement on twenty recommendations, using a 4-point Likert scale. Consensus was defined as >80% of participants scoring either 1 (totally agree) or 2 (agree).

RESULTS

In the first round of the Delphi questionnaire, 75% of the recommendations reached consensus. Those that were not agreed upon were reformulated by the steering committee and voted again after an online meeting, where consensus was achieved in all recommendations.

CONCLUSIONS

All recommendations reached consensus after the two-round Delphi questionnaire and may be useful in clinical practice for dermatologists. The participants agreed that besides this consensus, further clinical studies are needed to assess the benefits of the emerging tools and treatments and to clarify the controversies that still exist in the field, aiming at improving patients' quality of life.

Adiponectin as a novel biomarker of disease severity in alopecia areata

The frequent coexistence of obesity and metabolic syndrome in patients with alopecia areata may indicate the common pathogenetic pathway in these conditions with an important role of adipokines. The aim of the study was to evaluate the serum level of adiponectin, resistin and leptin in patients with alopecia areata in comparison to healthy controls. The study included 65 patients with alopecia areata and 71 healthy controls. The concentration of adipokines was determined with the enzyme-linked immunosorbent assay. The mean concentrations of adiponectin and resistin were significantly lower in the sera of patients with alopecia areata when compared to healthy controls (7966 \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\pm$$\end{document}± 4087 vs 9947 \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\pm$$\end{document}± 5692 ng/ml; p = 0.0312 and 11.04 \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\pm$$\end{document}± 3.88 vs 14.11 \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\pm$$\end{document}± 8.69 ng/ml; p = 0.0176, respectively). A negative correlation between the serum level of adiponectin and severity of alopecia tool (SALT) score was observed (r = − 0.26; p < 0.05). The concentration of adiponectin was significantly lower in patients with alopecia universalis than in patients with patchy alopecia areata (4951 \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\pm$$\end{document}± 2499 vs 8525 \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\pm$$\end{document}± 4085 ng/ml; p = 0.0135). No significant difference in the serum concentration of leptin was observed between patients with alopecia areata and healthy controls. The negative correlation between the serum level of adiponectin and hair loss severity indicates that adiponectin may be considered a marker of hair loss severity in alopecia areata. Further studies are needed to evaluate the role of resistin in patients with alopecia areata and its decreased level irregardless of severity or activity of the disease.

Metabolic syndrome in patients with Alopecia Areata: A case-control study

The aim of this study was to evaluate metabolic syndrome prevalence in patients with Alopecia Areata compared to controls. Sixty eligible patients with Alopecia Areata and 60 healthy subjects frequency matched for age and sex attending to our referral dermatology clinics from 2015 to 2017 were enrolled. Prevalence of metabolic syndrome and its components were compared between the two groups. Metabolic syndrome was only seen in seven patients (11.67%) and four controls (6.67%) without a significant difference (P = .34). The clinical presentations of AA included patch type (38.33%), ophiasis (6.67%), alopecia totalis (16.67%), and alopecia universalis (38.33%). Presence of metabolic syndrome was significantly associated with abdominal circumference (OR: 1.10, 95% CI for OR: 1.02to 1.19). Although there was no significant association between Alopecia Areata and metabolic syndrome, some components of metabolic syndrome were more prevalent in these patients. It may be concluded Alopecia Areata patients are at a higher risk of developing metabolic syndrome in the future. Further studies with larger sample sizes are needed.

Role of adiponectin and leptin in patients with alopecia areata with scalp hair loss

BACKGROUND/AIMS

Alopecia areata (AA) is considered an organ-specific autoimmune disease of hair follicles. Adipose tissue plays a role in lipid metabolism and glucose metabolism and secretes adipokines such as leptin and adiponectin. Dysregulation in the adipokine balance may be associated with metabolic syndrome. We aimed to determine serum adipokine levels in AA patients and compare them with healthy controls, and to determine whether there was metabolic syndrome and insulin resistance in the AA patients.

METHODS

A total of 70 participants were included in the study. Patients were divided into two subgroups: patients with scalp hair loss were in subgroup 1 (AA1). Patients with beard and eyebrow hair loss were in subgroup 2 (AA2). Serum adiponectin, leptin, TNF-α, insulin, fasting glucose, TG, and HDL were analyzed.

RESULTS

Thirty-six (25 male, 11 female) patients with AA and 34 (18 male, 16 female) healthy subjects were included in the study. Metabolic syndrome was detected in three of the AA patients and in two of the healthy subjects. Serum leptin, adiponectin, TNF-α, TG, HDL, and insulin levels and HOMA-IR scores were not statistically significant in patients compared with control subjects, except fasting glucose levels (p = 0.035). However, serum leptin and adiponectin levels were significantly higher in AA1 (n = 25) subgroup compared with the control group (p = 0.029, p = 0.026 respectively). There was a statistically significant increase in the fasting glucose level, while there were no differences in other parameters between the AA2 (n = 11) subgroup and the control group.

CONCLUSIONS

To our knowledge, this is the first report indicating that adiponectin and leptin probably has a role in the pathogenesis of AA with scalp hair involvement.