Acanthosis nigricans: a flag for insulin resistance

Association of acanthosis nigricans with metabolic syndrome - An analytic cross-sectional study

BACKGROUND

Globally, few studies have been undertaken to assess the association of acanthosis nigricans (AN) with metabolic syndrome (MS). Most of the available studies have either focused on a particular age group, gender, ethnicity or on a single component of MS.

OBJECTIVES

To determine the association between AN and MS as a whole and with all individual components of MS in adult patients of either gender.

MATERIAL AND METHODS

This was a cross-sectional study with a comparative group. Eighty-one subjects were recruited in each group. Fasting plasma glucose (FPG) and lipid profile were done. MS was defined by using the international diabetic federation (IDF) criteria. Association of body mass index (BMI), waist circumference, blood pressure, FPG, high-density lipoprotein (HDL) and triglycerides (TG) with AN was assessed by Pearson's chi-square test followed by univariate and multivariate analysis.

RESULTS

The prevalence of MS was found to be significantly higher in the group with AN. On univariate analysis, a significant association of AN was found with BMI, waist circumference, high systolic and diastolic blood pressure, HDL, and TG. Multivariate analysis revealed a significant association between waist circumference, high systolic and diastolic blood pressure, and high TG levels with AN. The risk of MS was found to be eight times higher in cases of AN.

STUDY LIMITATIONS

The small sample size and single-center data are the limitations of the present study.

CONCLUSION

AN is strongly associated with MS as a whole and with its individual components including increased waist circumference, hypertension, and dyslipidemia.

Therapeutic implications of dermoscopic findings in acanthosis nigricans: A clinical and histopathological study

Acanthosis nigricans is associated with numerous systemic disorders. These include endocrinological conditions such as, diabetes, acromegaly, Cushing's syndrome, thyroid dysfunction, as well as metabolic abnormalities like obesity and polycystic ovarian disease. Its association with visceral malignancy is known. Moreover, Acanthosis nigricans is known to be a cutaneous marker of insulin resistance (IR) and hyperinsulinemia. The primary aim of this study was to study clinical and histopathological patterns of acanthosis nigricans and its correlation with dermoscopic patterns and treatment implications. 103 patients clinically diagnosed as acanthosis nigricans were enrolled in the study. Clinical evaluation, dermoscopy, and skin biopsy was done for histopathological evaluation. Consistency was observed in the changes seen on dermoscopy with clinical and histopathological findings. Common dermoscopy findings were Crista Cutis, Sulcus Cutis, Papillary projections, hyperpigmented dots, crypts, and blotching Dermoscopic findings can be correlated with histopathological features. Dermoscopy allows visualization on higher magnification which helps to pick up subtle changes which are not visible to naked eye. Dermoscopy can be a useful tool to distinguish acanthosis nigricans from other pigmentary disorders in patients who are not willing for histopathological examination and helps in treatment making decisions.

Association of Acanthosis Nigricans and Acrochordon with Insulin Resistance: A Cross-Sectional Hospital-Based Study from North India

Background

Insulin resistance (IR) is a pre-diabetic condition and has been reported in patients with acanthosis nigricans (AN) and acrochordon. AN and acrochordon are claimed to be cutaneous markers of IR.

Aim

The purpose of this paper was to study the association of AN and acrochordon with IR.

Methods

It was a cross-sectional hospital-based study. Both groups were assessed for IR by using homeostatic model assessment of insulin resistance (HOMA-IR) formula.

Results

A total of 70 cases and an equal number of controls were studied. IR was observed more in cases (41.4%) compared to controls (17.1%) (P < 0.01). Mean HOMA-IR value was also significantly higher in cases (4.32 ± 4.44) compared to controls (2.27 ± 0.90) (P < 0.05).

Limitations

Low number of cases and controls were taken in the study. Association with hyperlipidemia and metabolic syndrome was not elicited.

Conclusions

AN and acrochordons were found to be associated with IR.

Association of Acanthosis Nigricans and Insulin Resistance in Indian Children and Youth - A HOMA2-IR Based Cross-Sectional Study

Introduction:

The American Diabetes Association includes acanthosis nigricans (AN) as an indicator of diabetes mellitus risk in overweight youth entering puberty. Some argue that AN is not an independent predictor of insulin resistance (IR), when body mass index (BMI) is controlled for. There is a paucity of studies on the association of AN and IR among children and young adults from India. Homeostatic model assessment-IR (HOMA2-IR), a computerized updated model, which is supposed to be superior to HOMA1-IR, has rarely been used for quantification of IR.

Methods:

Sixty cases (irrespective of BMI), aged 2–24 years with AN, and 30 age- and sex-matched normal weight controls were included. A thorough clinical examination and grading of AN was done. BMI, fasting glucose levels, and fasting insulin levels were measured for all. HOMA-IR calculator V.2.2.3 was used to calculate IR. Those with HOMA 2-IR >1.8 were considered insulin-resistant. Lifestyle modifications were advised for patients with IR.

Results:

The mean HOMA2-IR value in cases and controls was 2.422 and 1.322, respectively, which was statistically significant. Overweight and obese cases had 2.5 and 11.25 times higher risk of having IR, respectively, by logistic regression. The association of AN with IR was found to be statistically significant in normal weight cases when compared with controls (P = 0.045). Grade 4 of neck severity (P = 0.007), Grade 3 of neck texture (P = 0.001), and Grade 4 of axillary severity (P = 0.001) of AN were found to be significantly associated with IR.

Limitations:

The relatively small sample size may not reflect the accuracy of AN as a marker of IR.

Conclusion:

Acanthosis nigricans is associated with IR in both normal and obese. We propose that all children, adolescents, and youth with AN be screened for IR irrespective of BMI. Early identification and prompt lifestyle interventions may prevent or delay the onset of diabetes later.

Polycystic ovary syndrome (PCOS), an inflammatory, systemic, lifestyle endocrinopathy

Polycystic ovary syndrome (PCOS) is an endocrine disorder, afflicting females of reproductive age. This syndrome leads to infertility, insulin resistance, obesity, and cardiovascular problems, including a litany of other health issues. PCOS is a polygenic, polyfactorial, systemic, inflammatory, dysregulated steroid state, autoimmune disease, manifesting largely due to lifestyle errors. The advent of biochemical tests and ultrasound scanning has enabled the detection of PCOS in the affected females. Subsequently, a huge amount of insight on PCOS has been garnered in recent times. Interventions like oral contraceptive pills, metformin, and hormone therapy have been developed to bypass or reverse the ill effects of PCOS. However, lifestyle correction to prevent aberrant immune activation and to minimize the exposure to inflammatory agents, appears to be the sustainable therapy of PCOS. This holistic review with multiple hypotheses might facilitate to devise better PCOS management approaches.

Acanthosis Nigricans as a Clinical Predictor of Insulin Resistance in Obese Children

PURPOSE

This study aimed to evaluate the utility of acanthosis nigricans (AN) severity as an index for predicting insulin resistance in obese children.

METHODS

The subjects comprised 74 obese pediatric patients who attended the Department of Pediatrics at Chosun University Hospital between January 2013 and March 2016. Waist circumference; body mass index; blood pressure; fasting glucose and fasting insulin levels; lipid profile; aspartate transaminase, alanine transaminase, glycated hemoglobin, C-peptide, and uric acid levels; and homeostatic model assessment insulin resistance (HOMA-IR) and quantitative insulin check sensitivity index (QUICKI) scores were compared between subjects with AN and those without AN. Receiver operating characteristic curves were used to investigate the utility of the AN score in predicting insulin resistance. HOMA-IR and QUICKI were compared according to AN severity.

RESULTS

The With AN group had higher fasting insulin levels (24.1±21.0 mU/L vs. 9.8±3.6 mU/L, p<0.001) and HOMA-IR score (5.74±4.71 vs. 2.14±0.86, p<0.001) than the Without AN group. The AN score used to predict insulin resistance was 3 points or more (sensitivity 56.8%, specificity 83.9%). HOMA-IR scores increased with AN severity, from the Without AN group (mean, 2.15; 95% confidence interval [CI], 1.72-2.57) to the Mild AN (mean, 4.15; 95% CI, 3.04-5.25) and Severe AN groups (mean, 7.22; 95% CI, 5.08-9.35; p<0.001).

CONCLUSION

Insulin resistance worsens with increasing AN severity, and patients with Severe AN (AN score ≥3) are at increased risk of insulin resistance.