Acanthosis nigricans as a clinical marker of insulin resistance among overweight adolescents

Ketogenic diet ameliorates high-fat diet-induced insulin resistance in mouse skeletal muscle by alleviating endoplasmic reticulum stress

OBJECTIVE

Ketogenic diets (KD) have been shown to alleviate insulin resistance (IR) by exerting anti-lipogenic and insulin sensitizing effects in the liver through a variety of pathways. The present study sought to investigate whether a ketogenic diet also improves insulin sensitization in skeletal muscle cells through alleviating endoplasmic reticulum stress.

METHODS

High-fat diet-induced IR mice were allowed to a 2-week ketogenic diet. Insulin resistance and glucose tolerance were evaluated through GTT, ITT, and HOMA-IR. The C2C12 myoblasts exposed to palmitic acid were used to evaluate the insulin sensitization effects of β-hydroxybutyric acid (β-OHB). Molecular mechanisms concerning ER stress signaling activation and glucose uptake were assessed.

RESULTS

The AKT/GSK3β pathway was inhibited, ER stress signaling associated with IRE1, PERK, and BIP was activated, and the number of Glut4 proteins translocated to membrane decreased in the muscle of HFD mice. However, all these changes were reversed after 2 weeks of feeding on a ketogenic diet. Consistently in C2C12 myoblasts, the AKT/GSK3β pathway was inhibited by palmitic acid (PA) treatment. The endoplasmic reticulum stress-related proteins, IRE1, and BIP were increased, and the number of Glut4 proteins on the cell membrane decreased. However, β-OHB treatment alleviated ER stress and improved the glucose uptake of C2C12 cells.

CONCLUSION

Our data reveal that KD ameliorated HFD-induced insulin resistance in skeletal muscle, which was partially mediated by inhibiting endoplasmic reticulum stress. The insulin sensitization effect of β-OHB is associated with up regulation of AKT/GSK3β pathway and the increase in the number of Glut4 proteins on the cell membrane.

Clinical factors associated with remission of obese acanthosis nigricans after laparoscopic sleeve gastrectomy: a prospective cohort study

BACKGROUND

Acanthosis nigricans (AN) involves skin hyperpigmentation in body folds and creases. Obesity-associated AN (OB_AN) is the most common type of AN. The skin condition of obese patients with AN can be improved through bariatric surgery, such as laparoscopic sleeve gastrectomy (LSG), after weight loss. However, the contributing factors to the remission of AN after surgery are still not fully determined. The authors aimed to assess the metabolic and pathological factors associated with remission of AN following LSG in obese individuals.

METHODS

The study included 319 obese patients who underwent LSG at our hospital. The subjects were divided into obesity (OB) only (OB, n =178) or OB with AN (OB_AN, n =141) groups. The basic clinical and metabolic indices and the dermatological features via reflectance confocal microscopy and histology were collected from patients prior to and after LSG.

RESULTS

OB_AN patients had higher fasting plasma glucose, homeostatic model assessment for insulin resistance, and testosterone levels than OB patients. LSG could significantly improve the biochemical and histopathological features of OB_AN patients. The remissive rate of OB_AN patients was about 86.5% (122 out of 141) after surgery. The remission of OB_AN skin lesions was positively correlated with testosterone levels ( P <0.01). In addition, there was a significant positive correlation between changes in AN scores and epidermal thickness and skin pigmentation scores after surgery ( P <0.01).

CONCLUSION

The remissive rate of OB_AN after LSG is associated with improved testosterone levels and reduced epidermal thickness and skin pigmentation levels.

Pediatric obesity and skin disease: cutaneous findings and associated quality-of-life impairments in 103 children and adolescents with obesity

Objective

Little is known about specific cutaneous findings in children and adolescents with overweight and obesity. This study assessed the association of skin signs with pivotal auxological and endocrinological parameters and their influence on the quality of life (QoL) of young people with obesity.

Study design

All patients initially recruited for a tertiary hospital's weight control program were offered participation in this interdisciplinary, single-center, cross-sectional study. All participants underwent a detailed dermatological examination, anthropometric measurements and laboratory examinations. QoL was assessed with validated questionnaires.

Results

A total of 103 children and adolescents (age 11.6 ±2.5 years, 41% female, 25% prepubertal, BMI SDS 2.6 ± 0.5, homeostatic model assessment (HOMA) score 3.3 ± 4.2; mean ± s.d.) were recruited in a 12-month study period. Skin affections were linearly associated with increasing BMI and higher age. The most common skin findings were (%) striae distensae (71.0), keratosis pilaris (64.7), acanthosis nigricans (45.0), acne vulgaris (39.2), acrochordons (25.5) and plantar hyperkeratosis (17.6). The HOMA score was associated with acanthosis nigricans (P = 0.047), keratosis pilaris (P = 0.019) and acne vulgaris (P < 0.001). The general mean QoL(QoL) score, as assessed by the WHO-5, was 70 out of 100. A total of 38.9% of participants reported impaired dermatological QoL.

Conclusions

This study shows the high prevalence of skin lesions in children and adolescents with obesity. The association between skin lesions and the HOMA score indicates that skin manifestations are a marker of insulin resistance. To prevent secondary diseases and improve QoL, thorough skin examinations and interdisciplinary cooperation are necessary.

Single Point Insulin Sensitivity Estimator for predicting type 2 diabetes mellitus in obese adolescents

PURPOSE

The prevalence of adolescents with type 2 diabetes mellitus (T2DM) has rapidly increased in Korea over the past few decades with the increase in the number of obese adolescents. The single point insulin sensitivity estimator (SPISE) was recently introduced as a surrogate marker for insulin sensitivity to predict T2DM in adults. We aimed to determine risk factors for T2DM in obese adolescents, including SPISE.

METHODS

This retrospective study included 104 adolescents diagnosed with T2DM at Korea University Hospital between January 2010 and December 2020. We compared clinical and biochemical parameters and the SPISE of normoglycemic overweight and obese individuals with those of prediabetic and diabetic adolescents to determine risk factors for T2DM. Receiver operating characteristic analysis was performed with the Youden index to determine the cutoff point of SPISE.

RESULTS

Frequency of fatty liver and family history of T2DM were significantly higher and SPISE level was significantly lower in patients with T2DM than in normoglycemic overweight/obese and prediabetic adolescents (p<0.01). A family history of T2DM, fatty liver, and SPISE value below the cutoff point (4.49) were identified as significant risk factors for T2DM in multiple logistic regression analysis after controlling for age, sex, and body mass index standard deviation score (p<0.01).

CONCLUSION

Family history of T2DM, fatty liver, and low SPISE (<4.49) are risk factors that can independently affect the occurrence of T2DM in obese adolescents. Among these risk factors, SPISE is a promising marker for predicting adolescent T2DM; careful monitoring of these individuals is needed to prevent progression to T2DM.

Acanthosis Nigricans: An Updated Review

BACKGROUND

Early recognition of acanthosis nigricans is important because acanthosis nigricans can be a cutaneous manifestation of a variety of systemic disorders and, rarely, as a sign of internal malignancy.

OBJECTIVE

The purpose of this article is to familiarize pediatricians with the clinical manifestations, evaluation, diagnosis, and management of acanthosis nigricans.

METHODS

A search was conducted in November 2021in PubMed Clinical Queries using the key term "acanthosis nigricans". The search strategy included all clinical trials, observational studies, and reviews published within the past 10 years. Only papers published in the English literature were included in this review. The information retrieved from the above search was used in the compilation of the present article.

RESULTS

Acanthosis nigricans is characterized by symmetric, hyperpigmented, and velvety plaques with ill-defined borders, typically involving intertriginous areas. Obesity is the most common cause of acanthosis nigricans which is increasingly observed in obese children and adolescents and can serve as a cutaneous marker of insulin resistance. Early recognition of acanthosis nigricans is important because acanthosis nigricans can also be a cutaneous manifestation of a variety of systemic disorders and, rarely, as a sign of internal malignancy. This may consist of weight reduction, discontinuation of causative drugs, treatment of underlying endocrinopathy, or treatment of an underlying malignancy. For patients with isolated acanthosis nigricans and for those whose underlying cause is not amenable to treatment, treatment of the lesion may be considered for cosmetic reasons. Topical retinoids, vitamin D analogs, chemical peels, and other keratolytics are often used for the treatment of localized lesions. Seldom, systemic therapy such as oral retinoids may be considered for extensive or generalized acanthosis nigricans and acanthosis nigricans unresponsive to topical therapy. Other uncommon treatment modalities include dermabrasion, laser therapy, and surgical removal.

CONCLUSION

Although acanthosis nigricans is treatable, a complete cure is difficult to achieve. The underlying cause should be treated, if possible, to resolve and prevent the recurrence of acanthosis nigricans. The diagnosis is mainly clinical, based on the characteristic appearance (symmetrically distributed, hyperpigmented, velvety, papillomatous, hyperkeratotic plaques with ill-defined borders) and the typical sites (intertriginous areas, flexural area, and skin folds) of the lesions. The diagnosis might be difficult for lesions that have atypical morphology or are in an unusual location. Clinicians should be familiar with the clinical signs, evaluation, diagnosis, and therapy of acanthosis nigricans because of the link between it and underlying diseases.

Association between childhood obesity and familial salt intake: analysis of data from Korean National Health and Nutrition Examination Survey, 2014-2017

High salt intake is known as a risk factor of childhood obesity. As family members share not only genes but also their diet habit, parents' salt intake may affect to their children's obesity. In this study, we investigated correlations between childhood obesity and parents' or children's sodium intakes based on a nationwide survey data. From the Korean National Health and Nutrition Examination Survey data from 2014 to 2017, 802 boys and 657 girls aged 10-18 years, and their parents were included. BMI z-score and 24-hour urinary sodium excretion, which is estimated through Tanaka's equation, were used to examine associations between obesity and sodium intakes. The BMI status and the prevalence of obesity between children and their parents showed strong positive correlations in both sexes (all p < 0.001). The urinary sodium excretion between children and their parents showed positive correlations in both sexes (all p < 0.05). Children with higher urinary sodium excretion showed higher BMI (in both sexes, p < 0.001) and higher parental obesity compared to those with lower urinary sodium excretion, however, statistical significances of the latter relationship were varied by sex. In conclusion, our study suggests close relationship between childhood obesity and their sodium intakes, which also correlate well with parental BMIs and diet behavior. Therefore, parental education and active participation could be crucial in regulating childhood obesity.

Management of severe pediatric obesity

Background: Pediatric obesity has increased over the decades, and in particular, severe pediatric obesity has become a serious public health problem. A concern has arisen that the COVID-19 pandemic may exacerbate the incidence of childhood obesity.Current Concepts: The consequences of severe pediatric obesity are more devastating than those of moderate obesity. Children with severe obesity are at a greater risk for hypertension, type 2 diabetes, metabolic syndrome, non-alcoholic fatty liver disease, atherosclerosis, and adult obesity. Correct assessment and diagnosis of a child with severe obesity is key to successful therapy. A thorough history and physical examination are important in identifying monogenic obesity or metabolic syndrome. Eating behaviors and psychosocial factors should be assessed to improve weight management outcomes. Treatment options for severe pediatric obesity include lifestyle modification, pharmacotherapy, and metabolic and bariatric surgery. Even though progress has been made with regard to the treatment of obesity, safe and effective treatment of severe pediatric obesity is challenging.Discussion and Conclusion: More efforts and innovations are needed to find a solution for the huge medical and emotional burden the children with severe obesity and their families are enduring.

A Molecular Perspective on the Potential Benefits of Metformin for the Treatment of Inflammatory Skin Disorders

Due to its anti-hyperglycemic effect, metformin is the first-line medication for the treatment of type 2 diabetes, particularly in people who are obese. However, metformin is a drug with a very wide range of pharmacological properties and reports of its therapeutic effect on diseases including inflammation and cancer are increasing. Numerous research groups have reported that metformin has beneficial effects on a variety of inflammatory skin disorders including psoriasis, acanthosis nigricans, acne, hidradenitis suppurativa, and allergic contact dermatitis. According to these reports, in addition to the well-known action of metformin, that is, its anti-hyperglycemic effect, NF-kB inhibition and the resulting alteration to the cytokine network may be the potential targets of metformin. Its anti-hyperandrogenism effect has also been confirmed as the major action of metformin in some inflammatory skin diseases. Moreover, novel regulatory mechanisms, including autophagy and antioxidant processes, have been suggested as promising mechanisms of action for metformin in inflammatory skin disorders.