Relation between acanthosis nigricans and insulin sensitivity in overweight Hispanic children at risk for type 2 diabetes

Predicting Insulin Resistance in a Pediatric Population With Obesity

OBJECTIVES

Insulin resistance (IR) affects children and adolescents with obesity and early diagnosis is crucial to prevent long-term consequences. Our aim was to identify predictors of IR and develop a multivariate model to accurately predict IR.

METHODS

We conducted a cross-sectional analysis of demographical, clinical, and biochemical data from a cohort of patients attending a specialized Paediatric Nutrition Unit in Portugal over a 20-year period. We developed multivariate regression models to predict IR. The participants were randomly divided into 2 groups: a model group for developing the predictive models and a validation group for cross-validation of the study.

RESULTS

Our study included 1423 participants, aged 3-17 years old, randomly divided in the model (n = 879) and validation groups (n = 544). The predictive models, including uniquely demographic and clinical variables, demonstrated good discriminative ability [area under the curve (AUC): 0.834-0.868; sensitivity: 77.0%-83.7%; specificity: 77.0%-78.7%] and high negative predictive values (88.9%-91.6%). While the diagnostic ability of adding fasting glucose or triglycerides/high density lipoprotein cholesterol index to the models based on clinical parameters did not show significant improvement, fasting insulin appeared to enhance the discriminative power of the model (AUC: 0.996). During the validation, the model considering demographic and clinical variables along with insulin showed excellent IR discrimination (AUC: 0.978) and maintained high negative predictive values (90%-96.3%) for all models.

CONCLUSION

Models based on demographic and clinical variables can be advantageously used to identify children and adolescents at moderate/high risk of IR, who would benefit from fasting insulin evaluation.

Diet and Acanthosis Nigricans over a Two-Year Period in Children of the Pacific Region

BACKGROUND

The impact that dietary carbohydrates have on children developing type 2 diabetes remains controversial. Furthermore, there are limited pediatric longitudinal studies on changes in body mass index (BMI) and diet related to the development of acanthosis nigricans (AN), a risk factor associated with type 2 diabetes.

METHODS

Two 24 h dietary records were collected for 558 children, 2-8 years of age, at baseline and at a 2-year follow-up. Data on age, sex, BMI, and the presence of AN were also collected at each time point from the Children's Healthy Living Program. Logistic regression was used to determine factors associated with the presence of AN at follow-up. Multinominal regression was used to determine factors associated with changes in AN status. Linear regression was used to measure the associations between changes in dietary intake and in the Burke Score for AN.

RESULTS

AN was present in 28 children at baseline and 34 children at follow-up. Adjusting for the presence of AN at baseline, age, sex, study group, baseline BMI, change in BMI z-score, time between assessments, and baseline intake, an increase from baseline for each teaspoon of sugar and serving of carbohydrate-rich food increased the risk for having AN at follow-up by 9% and 8%, respectively (p ≤ 0.05). An increased intake of added sugar (teaspoons) increased the risk of developing AN by 13% (p ≤ 0.01) and an increase in servings of foods rich in starch increased the risk of developing AN by 12% (p ≤ 0.01) compared to children who never had AN. Increasing the intake of fruit was also associated with decreased Burke Scores using multiple regression. However, the intake of energy and macronutrients were not associated with AN.

CONCLUSIONS

Added sugar and foods rich in starch were independently associated with the occurrence of AN, suggesting the type of carbohydrates consumed is a factor in AN occurrence.

Acanthosis nigricans as a composite marker of cardiometabolic risk and its complex association with obesity and insulin resistance in Mexican American children

AIM

Acanthosis nigricans (AN) is a strong correlate of obesity and is considered a marker of insulin resistance (IR). AN is associated with various other cardiometabolic risk factors (CMRFs). However, the direct causal relationship of IR with AN in obesity has been debated. Therefore, we aimed to examine the complex causal relationships among the troika of AN, obesity, and IR in Mexican Americans (MAs).

METHODS

We used data from 670 non-diabetic MA children, aged 6-17 years (49% girls). AN (prevalence 33%) severity scores (range 0-5) were used as a quasi-quantitative trait (AN-q) for analysis. We used the program SOLAR for determining phenotypic, genetic, and environmental correlations between AN-q and CMRFs (e.g., BMI, HOMA-IR, lipids, blood pressure, hs-C-reactive protein (CRP), and Harvard physical fitness score (PFS)). The genetic and environmental correlations were subsequently used in mediation analysis (AMOS program). Model comparisons were made using goodness-of-fit indexes.

RESULTS

Heritability of AN-q was 0.75 (p<0.0001). It was positively/significantly (p<0.05) correlated with traits such as BMI, HOMA-IR, and CRP, and negatively with HDL-C and PFS. Of the models tested, indirect mediation analysis of BMI→HOMA-IR→AN-q yielded lower goodness-of-fit than a partial mediation model where BMI explained the relationship with both HOMA-IR and AN-q simultaneously. Using complex models, BMI was associated with AN-q and IR mediating most of the CMRFs; but no relationship between IR and AN-q.

CONCLUSION

Our study suggests that obesity explains the association of IR with AN, but no causal relationship between IR and AN in Mexican American children.

Acanthosis nigricans in childhood: A cutaneous marker that should not be underestimated, especially in obese children

AIM

The occurrence of acanthosis nigricans (AN) in childhood should not be underestimated since it acts as a cutaneous marker of underlying diseases, such as insulin resistance, endocrinopathy, syndromes and malignancy. The purpose of this review was to highlight the clinical significance of AN in childhood and draw attention to its possible role as early marker of alterations in glucose metabolism in obese children.

METHODS

The Cochrane Library and PubMed databases were searched for papers published in English up to April 2019. Observational studies, case reports and reviews from 1994 to 2019 were included.

RESULTS

Most of the cases of AN are associated with obesity. The prevalence of obesity is rising worldwide and is paralleled by global increases in the prevalence of metabolic syndrome in children. Insulin resistance and AN are closely associated. Evidence indicates that AN is a useful clinical marker for the identification of obese and overweight children and adolescents with insulin resistance who are susceptible to type 2 diabetes mellitus and metabolic syndrome.

CONCLUSION

In clinical practice, the recognition of AN is useful for an early identification of children and adolescents, prone to the insulin-resistant obese phenotype, who could benefit from early interventions.

Acanthosis Nigricans in the Knuckles of Infants: A Novel Clinical Marker of High Metabolic Risk

INTRODUCTION

Acanthosis nigricans (AN) is an early clinical sign of insulin resistance (IR) primarily in adults. The prevalence and association of AN and IR in infants, however, remains uncertain. We aimed to describe the prevalence of AN and its association with IR in a group of Latin-American infants.

METHODS

We studied a random sample of 227 healthy infants between 9 and 24 months of age. After a complete clinical history was obtained and a physical examination was performed, fasting plasma glucose and serum insulin were measured. Three blinded evaluators assessed AN in each patient. Infants with AN were categorized as cases. The HOMA-IR index cutoffs of ≥ 90th and ≥ 95th percentiles were considered IR.

RESULTS

There were 49 infants with AN (21.6%) (cases) and 178 without AN (78.4%) (controls). Cases had a significantly higher mean serum insulin, fasting plasma glucose, and HOMA-IR levels of 3.67 ± 2.56 µU/ml vs. 2.42 ± 1.45 µU/ml, P = 0.005; 84.2 ± 12.6 mg/dL vs. 77 ± SD 9.9 mg/dL, P ≤ 0.001; HOMA-IR 0.77 ± 0.54 vs. 0.46 ± 0.28, P ≤ 0.001, respectively. More cases than controls presented HOMA-IR levels ≥ 95th percentile (cases 18.4%; controls 0.5%, P ≤ 0.001) and ≥ 90th percentile (cases 32.7%; controls 1.6%, P ≤ 0.001). AN in the knuckles had a high sensitivity and a negative predictive value (NPV) for detecting patients with HOMA-IR levels above the 95th percentile (sensitivity 90%; NPV 99.4%) and above the 90th percentile (sensitivity 84.2%; NPV 98.3%).

CONCLUSION

AN in the knuckles is a prevalent, non-invasive, costless, and reliable screening clinical tool that can be used for early detection of infants with IR and a high metabolic risk.

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

PURPOSE

Acanthosis nigricans (AN) is a hyperpigmented dermatosis associated with obesity and insulin resistance (IR). There is no consensus whether AN extension scoring offers added value to the clinical estimation of IR. In this study we aimed to assess and score AN using both a short and an extended version of the scale proposed by Burke et al. and analyze the relationships of both versions with hyperinsulinemia and IR.

METHODS

We analyzed data from 139 overweight adolescents (body mass index ≥85th percentile) aged 12-18 with (n=67) or without (n=72) AN who were followed at a pediatric obesity clinic.

RESULTS

Adolescents with AN had higher levels of insulin (d=0.56, P=0.003) and HOMA-IR (d=0.55, P=0.003) compared to those without. Neither the short nor the extended versions of AN scores explained either hyperinsulinemia (β=1.10, P=0.316; β=1.15, P=0.251) or IR (β=1.07, P=0.422; β=1.10, P=0.374). The presence of AN alone predicted hyperinsulinemia and the presence of IR in 7.3% (β=2.68, P=0.008) and 7.1% (β=2.59, P=0.009) of adolescents, respectively.

CONCLUSION

Screening for AN at the neck and axilla is a noninvasive and cost-effective way to identify asymptomatic overweight adolescents with or at risk of developing IR.

Type 2 Diabetes in Latino Youth: A Clinical Update and Current Challenges

Latino youth have the highest prevalence of overweight and obesity among all ethnic groups and are disproportionally affected by pre diabetes and type 2 diabetes (T2DM). Interventions that effectively reduce the risk of pre diabetes and T2DM in this population are urgently needed. Studies have shown that without any change, 50% of Latino children and adolescents will develop T2DM. This has important public health implications. Few pharmacologic options are approved for use in the pediatric population. The largest clinical trial to date did include a significant sample of Latinos, however the intervention used metformin or rosiglitazone in addition to lifestyle management and did not show meaningful weight loss, with around half of the participants meeting criteria for treatment failure. On the other hand, a smaller trial on surgical treatment of adolescents with severe obesity and T2DM resulted in superior glycemic control, reduced weight, and improvement of other co-morbidities of T2DM in youth. Lastly, culturally tailored programs that focus on building healthy communities appear to be a promising intervention to reduce diabetes risk in Latino youth. This review provides an update on the clinical aspects of T2DM in Latino youth and focuses on management and prevention strategies.

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.

Type 2 diabetes mellitus in children and adolescent: an Indonesian perspective

The prevalence of type 2 diabetes mellitus (T2DM) in children and adolescents has increased globally over the past 2 decades. Metabolic syndrome, including obesity and overweight at a young age, increases the occurrence of T2DM. Studies in Indonesia have found that obese children and adolescents are more likely to have insulin resistance, a risk factor for T2DM. There are no data on the current incidence of T2DM in youth in Indonesia, but there has been a significant rise in the prevalence of overweight in adolescents. The diagnosis of T2DM in youth is similar to that in adults, with special consideration of when to test asymptomatic children. Management of T2DM in Indonesia follows the recommendations of the Indonesian Pediatric Society, which include lifestyle modifications, such as improving dietary habits and exercise, as well as appropriate medications. Metformin is the drug of choice for young T2DM patients; if marked hyperglycemia is present, basal insulin is given with metformin. Monitoring of T2DM is generally done through selfmonitoring of blood glucose and glycosylated hemoglobin.

Glucose alteration and insulin resistance in asymptomatic obese children and adolescents

OBJECTIVE

Obesity is associated with the abnormal glucose metabolism preceding type 2 diabetes mellitus. Thus, further investigation on the prediction of this lethal outcome must be sought. The objective was the profile glycemic assessment of asymptomatic obese children and adolescents from Salvador, Brazil.

METHOD

A fasting venous blood sample was obtained from 90 consecutive obese individuals aged 8-18 years, of both sexes, for laboratory determinations of glycated hemoglobin, basal insulin, and the Homeostasis Model Assessment Insulin Resistance index. The clinical evaluation included weight, height, waist circumference, assessment of pubertal development, and acanthosis nigricans research. The body mass index/age indicator was used for the severity of overweight assessment.

RESULTS

Glycemic alterations were evidenced clinically and biochemically, although these individuals had no complaints or symptoms related to blood sugar levels. Quantitative and qualitative variables were respectively expressed measures of central tendency/dispersion and simple/relative frequency, using the SPSS, version 20.0. A p-value <0.05 was considered significant.

CONCLUSION

Notably, this study found a high prevalence of glucose and insulin disorders in asymptomatic obese children and adolescents.

Fetal Overnutrition and Adolescent Hepatic Fat Fraction: the Exploring Perinatal Outcomes in Children Study

OBJECTIVE

To determine if fetal overnutrition resulting from maternal obesity or gestational diabetes mellitus (GDM) is associated with increased liver fat during adolescence, adjusting for past and current metabolic risk factors.

STUDY DESIGN

Data come from a historical prospective cohort study (Exploring Perinatal Outcomes in Children) of 254 mother-child pairs in Colorado who participated in 2 research visits at T1 (mean age 10.4, SD = 1.5 years) and at T2 (mean age 16.4, SD = 1.5 years), and had complete exposure and outcome data. Multiple linear regression was used to evaluate the effects of pre-pregnancy body mass index (BMI) and GDM on hepatic fat fraction (HFF) by magnetic resonance imaging at T2.

RESULTS

Maternal pre-pregnancy obesity (BMI 30+) was significantly associated (β = 1.59, CI = 0.66, 2.52) with increased HFF relative to mothers with normal pre-pregnancy weight (BMI <25) independent of maternal GDM and sociodemographic factors. Moreover, this association was independent of T2 and T1 metabolic risk factors (acanthosis nigricans, BMI, fasting glucose) (β = 1.03, CI = 0.10, 1.97). Prenatal GDM exposure was not associated with HFF in either unadjusted or adjusted models.

CONCLUSIONS

Maternal pre-pregnancy obesity was associated with increased HFF in offspring independent of childhood and adolescent adiposity. Intervention studies are needed to test the hypothesis that maternal obesity is a modifiable risk factor for childhood fatty liver disease.

Melatonin Treatment Improves Insulin Resistance and Pigmentation in Obese Patients with Acanthosis Nigricans

OBJECTIVE

This study aimed to determine the effects of melatonin on insulin resistance in obese patients with acanthosis nigricans (AN).

METHODS

A total of 17 obese patients with acanthosis nigricans were recruited in a 12-week pilot open trial. Insulin sensitivity, glucose metabolism, inflammatory factors, and other biochemical parameters before and after the administration of melatonin were measured.

RESULTS

After 12 weeks of treatment with melatonin (3 mg/day), homeostasis model assessment insulin resistance index (HOMA-IR) (8.99 ± 5.10 versus 7.77 ± 5.21, p < 0.05) and fasting insulin (37.09 5 ± 20.26 μU/ml versus 32.10 ± 20.29 μU/ml, p < 0.05) were significantly decreased. Matsuda index (2.82 ± 1.54 versus 3.74 ± 2.02, p < 0.05) was significantly increased. There were also statistically significant declines in the AN scores of the neck and axilla, body weight, body mass index, body fat, visceral index, neck circumference, waist circumference, and inflammatory markers.

CONCLUSIONS

It was concluded that melatonin could improve cutaneous symptoms in obese patients with acanthosis nigricans by improving insulin sensitivity and inflammatory status. This trial is registered with ClinicalTrials.gov NCT02604095.

Prevalence of Acanthosis nigricans and Related Factors in Iranian Obese Children

INTRODUCTION

Recognition of Acanthosis nigricans (AN) provides important opportunities for screening of obesity syndrome, dyslipidemia, hypertension and insulin resistance with diabetes mellitus 2. Considering the high prevalence of obesity among Iranian children, we designed this study to estimate the prevalence of AN and related laboratory factors in Iranian obese children.

MATERIALS AND METHODS

Seventy-one obese children were enrolled in this study. Diagnosis of AN was done by clinical examination. Body mass index (BMI), fasting blood sugar, total cholesterol, triglycerides (TG), alanine aminotransferase, aspartate aminotransferase (AST), alkaline phosphatase, high- and low-density lipoprotein cholesterol, insulin, thyroid-stimulating hormone, free thyroxin (fT4), calcium, phosphorus and 25-hydroxyvitamin D were measured with routine techniques. Collected data were compared between cases with AN and without AN. Independent t-test was used for comparison of variables.

RESULTS

Twenty-five of children were female (35.2%). Forty-eight children (67.6%) had AN. In 20 cases (28.2%), homeostasis model assessment-insulin resistance (HOMA-IR) was <2.5 and in 51 (71.8%), HOMA-IR was more than 2.5. Mean BMI, insulin, HOMA-IR, TG and AST levels were significantly higher in cases with AN.

CONCLUSION

Obese children with AN are at risk of developing diabetes. Hence early identification of this feature and precise evaluation of children is recommended.

Comparison of A1C to Oral Glucose Tolerance Test for the Diagnosis of Prediabetes in Overweight and Obese Youth

IN BRIEF This study reports performance of A1C against the oral glucose tolerance test (OGTT) in predicting prediabetes among overweight and obese African-American and Caribbean children. A retrospective chart review was completed for 230 children. Receiver operating characteristic curves were generated to find the predictive performances of different tests against the OGTT. A1C alone is a poor discriminator of prediabetes in our study population, with low sensitivity (70%) and specificity (48.8%). BMI z score, A1C, and homeostatic model assessment of insulin resistance are significant predictors of prediabetes and, when taken together, provide better discrimination for prediabetes.

Correlates of Leisure-Time Physical Activity Participation Among Latino Children and Adolescents with Acanthosis Nigricans

Little is known about leisure-time physical activity (LTPA) correlates in high-risk youth prone to obesity, insulin resistance, and associated morbidities. This study examined LTPA correlates among Latino youth identified with acanthosis nigricans (AN), a skin condition typically caused by metabolic impairment. Data were collected on 305 AN-positive Latino youth of ages 5-15 and one of their biological parents in 2012 from Texas. Ordinal logit regression was performed to analyze the data. Five health and behavioral LTPA correlates were identified, including child time spent in TV watching or videogame playing (OR of highest quartile vs. lowest quartile = 0.45; p = 0.01), child fair/poor health (OR 0.42; p = 0.01), parent obesity (OR 0.63; p = 0.06), parent daily physical exercise for more than 30 min (OR 2.20; p < 0.01), and parent housework time (OR 0.76; p < 0.05). Parent socioeconomic status was insignificant. For at-risk Latino youth, physical activity intervention strategies should take both behavioral and health factors into account.

Acanthosis nigricans in obese adolescents: prevalence, impact, and management challenges

Obesity in adolescence is a public health priority because it usually tracks into adulthood, resulting in enormous medical and social costs. This underscores the importance of early identification and intervention. Acanthosis nigricans (AN) was once considered a rare paraneoplastic dermatosis, but is now frequently observed in obese adolescents. Current understanding suggests that it is associated with insulin resistance and has a unique role in secondary prevention. The purpose of this narrative review is to provide a comprehensive overview of AN in obese adolescents, covering its history, current knowledge on the condition, its clinical significance, management challenges, and the direction of future research.

Association of the Family Nutrition and Physical Activity Screening Tool with Weight Status, Percent Body Fat, and Acanthosis Nigricans in Children from a Low Socioeconomic, Urban Community

OBJECTIVE

OBJECTIVE

To examine the association of the Family Nutrition and Physical Activity (FNPA) screening tool with weight status, percent body fat, and acanthosis nigricans (AN) in 6- to 13-year-old children from a low socioeconomic, urban community.

METHODS

Children (n=415) from four elementary schools located around Flint, Michigan were assessed for body mass index, percent body fat, and AN. The FNPA screening tool was completed by parents. Mann-Whitney U tests were used to assess differences in FNPA score by sex and presence of AN. Logistic regression was used to evaluate the association of the FNPA (tertiles) with weight status and AN.

RESULTS

Children with AN (13.7%) had a significantly lower FNPA score (56.3 + 7.1) compared with children without AN (61.0 + 7.1; P<.05). Children with FNPA scores in the lowest tertile (high-risk) had odds ratios of 1.74 (95% CI =1.05 - 2.91) and 2.77 (95% CI =1.22 - 6.27) compared with children with FNPA scores in the highest tertile (low-risk) for being overfat and having AN, respectively.

CONCLUSION

Although the FNPA screening tool did not predict risk for being overweight or obese, it was significantly associated with an increased odds of children at risk for being overfat or having AN.

Skin disorders in overweight and obese patients and their relationship with insulin

INTRODUCTION

The prevalence of obesity has increased worldwide in recent years. Some authors have described skin conditions associated with obesity, but there is little evidence on the association between insulin levels and such disorders.

OBJECTIVE

To describe the skin disorders present in overweight and obese patients and analyze their association with insulin levels.

MATERIAL AND METHODS

The study included nondiabetic male and female patients over 6 years of age who were seen at our hospital between January and April 2011. All the patients were evaluated by a dermatologist, who performed a physical examination, including anthropometry, and reviewed their medical history and medication record; fasting blood glucose and insulin were also measured. The patients were grouped according to degree of overweight or obesity and the data were compared using analysis of variance or the χ(2) test depending on the type of variable. The independence of the associations was assessed using regression analysis.

RESULTS

In total, 109 patients (95 adults and 13 children, 83.5% female) were studied. The mean (SD) age was 38 (14) years and the mean body mass index was 39.6±8 kg/m(2). The skin conditions observed were acanthosis nigricans (AN) (in 97% of patients), skin tags (77%), keratosis pilaris (42%), and plantar hyperkeratosis (38%). Statistically significant associations were found between degree of obesity and AN (P=.003), skin tags (P=.001), and plantar hyperkeratosis. Number of skin tags, AN neck severity score, and AN distribution were significantly and independently associated with insulin levels.

CONCLUSIONS

AN and skin tags should be considered clinical markers of hyperinsulinemia in nondiabetic, obese patients.

A cross-sectional study of Jamaican adolescents' risk for type 2 diabetes and cardiovascular diseases

OBJECTIVES

To compare obese versus non-obese Jamaican adolescents' risk for type 2 diabetes (T2D) and cardiovascular diseases (CVDs); and to explore a suitable and economical method of screening for these risk factors in the school settings.

DESIGN

A descriptive cross-sectional study of adolescents' risk for T2D and CVD. All the participants were examined at their respective schools.

SETTING

Jamaica, West Indies.

POPULATION

276 Jamaican adolescents aged 14-19 years, randomly selected from grades 9 to 12 from 10 high schools on the island and included both boys and girls. All ethnicities on the island were represented.

MAIN OUTCOME MEASURES

High fasting blood glucose, total cholesterol, glycated haemoglobin (HbA1c), blood pressure, body mass index (BMI), waist circumference, waist-to-hip ratio, family history of obesity, T2D and CVDs, low physical activity, and presence of Acanthosis Nigricans. All blood measures were analysed using the finger prick procedure.

RESULTS

Waist circumference, waist-to-hip ratio, Acanthosis Nigricans, total cholesterol, family history of T2D and blood pressure were the strongest predictors of BMI (p=0.001). Over one-third of the participants were overweight. Jamaican adolescent females had a significantly higher number of risk factors and were less physically active than males (p<0.05). Over 80% of participants reported ≥3 risk factors for T2D and CVD. Participants with BMI ≥25 reported five or more risk factors. One-third of the overweight participants were classified with metabolic syndrome.

CONCLUSIONS

Jamaican adolescents are at risk of T2D and CVD. Family history of disease and anthropometric measures identified more participants at risk than did the blood measures. Jamaican adolescent females reported more risk factors for T2D and CVD as compared to males. Collection of this type of data was feasible within the school settings. All data were collected in 1 day per school. Intervention measures are needed to educate Jamaican adolescents to reduce overweight and subsequently the risk factors.

The association between acanthosis nigricans and dysglycemia in an ethnically diverse group of eighth grade students

OBJECTIVE

The purpose of this study was to describe the prevalence of acanthosis nigricans (AN) and to quantify its association with dysglycemia in an ethnically diverse group of eighth-grade students.

DESIGN AND METHODS

Data were collected in 2003 from a cross-sectional study of students from 12 middle schools in three US states. Sex, race/ethnicity, and pubertal status were self-reported. Anthropometric measures were recorded. Trained staff identified the presence and severity of AN by inspection of the back of the neck. Fasting and 2 h blood samples were analyzed for impaired fasting glucose (IFG), impaired glucose tolerance (IGT), and high-risk glycated hemoglobin (A1C), respectively, defined as ≥100 mg/dl, ≥140 mg/dl, and ≥ 5.7-6.4%.

RESULTS

Overall, 25.0%, 58.2%, and 16.8% were Black, Hispanic, and White, respectively. AN was present among 406/1,438 (28.2%) of students: 39% among Black, 30% among Hispanic, and 5.4% among White. IGT and high-risk A1C were present among 2.1%, and 12.4%, respectively. In multivariate logistic modeling after adjusting for gender, family history of diabetes, BMI percentile, and pubertal staging, the presence (vs. absence) of AN was associated with a 59% increased likelihood of high-risk A1C: (P = 0.04), twice the likelihood of IGT (P = 0.06), and 47% greater likelihood of IGT/IFG combined (P < 0.0001). Adjustment for insulin attenuated the ORs by 25-70%.

CONCLUSION

In a racially/ethnically diverse sample of US adolescents, AN was common, occurring in 28% of the sample. AN was associated with a 50-100% increased likelihood of dysglycemia even after consideration of established diabetes risk factors.

Predicting metabolic syndrome in obese children and adolescents: look, measure and ask

OBJECTIVE

To verify in obese children whether or not the presence of (i) high waist-to-height ratio (WHtR), (ii) family history for type 2 diabetes (T2D) and (iii) acanthosis nigricans (AN), singularly or together, might predict the occurrence of metabolic syndrome or prediabetes.

METHODS

1,080 Italian obese children (567 females) were enrolled. Blood pressure, fasting plasma glucose, insulin, and lipids were measured, and oral glucose tolerance test (OGTT) was performed. The WHtR was calculated, family history for T2D was assessed, and the presence of AN was noticed. The odds ratios for showing metabolic syndrome and/or prediabetes according to the presence of these features were calculated.

RESULTS

The prevalence of metabolic syndrome was 29.2%. AN (OR1.81; p = 0.002) and WHtR higher than 0.60 (OR 2.24; p < 0.0001) were the clinical signs linked to higher risk for showing metabolic syndrome, and the odds raised significantly when these elements occurred simultaneously (OR 3.34; p < 0.0001). T2D family history (OR 2.36; p = 0.01) and WHtR higher than 0.60 (OR 2.32; p = 0.009) were the two features associated with increased odds of showing prediabetes.

CONCLUSIONS

Three simple actions, i.e., looking at the patient, asking about T2D family history, and measuring WHtR, may represent a powerful tool in the hands of pediatricians to identify obese children with high cardiovascular and metabolic risk.

Acanthosis nigricans predicts the clustering of metabolic syndrome components in Hispanic elementary school-aged children

BACKGROUND

Acanthosis nigricans (AN) is a dermatologic condition associated with hyperinsulinemia, a marker of insulin resistance that is the principal abnormality in metabolic syndrome (MetS). We examined the association of AN with the clustering of MetS components.

METHODS

A cross-sectional study was conducted in an urban school-based health center in New Mexico. Students without diabetes were evaluated for AN, a family history of type 2 diabetes, body mass index (BMI), and MetS components. The clustering of MetS components by BMI category and AN status was assessed by comparing the group means of summed average z-scores of fasting insulin, triglycerides, high-density lipoprotein-cholesterol, and systolic blood pressure among the students. A multivariate model with BMI category and AN status controlling for Tanner stage was performed to identify the variables associated with the clustering of MetS components.

RESULTS

Complete data were available for 90 children (age, 9.7±1.4 years; 94% Hispanic; 60% female). In multivariate modeling of MetS cluster z-score, significant differences were found between the students with BMI <85th percentile [-0.27; 95% confidence interval (95% CI)=-0.42 to -0.11] and (a) the students with BMI 85th-94.9th percentile with AN (0.74; 95% CI=0.17-1.31) and (b) the students with BMI ≥95th percentile with AN (0.86; 95% CI=0.54-1.18). No significant differences in the MetS cluster z-score were seen between the students with BMI <85th percentile and those with BMI 85th-94.9th percentile without AN (0.24; 95% CI=-0.33 to 0.81) or those with BMI ≥95th percentile without AN (0.31; 95% CI=-0.13 to 0.75).

CONCLUSIONS

Overweight/obese Hispanic elementary school-aged children with AN exhibit clustering of MetS components and could benefit from early intervention.

Is acanthosis nigricans a reliable indicator for risk of type 2 diabetes in obese children and adolescents? A systematic review

Obesity and type 2 diabetes is becoming a major health problem affecting children and adolescents in the United States. This article reviews the current literature examining the association between the presence of acanthosis nigricans (AN) and risk for developing type 2 diabetes mellitus (T2DM) in obese children and adolescents. Ethnicity, family history of diabetes, and emergence of obesity are contributing factors for development of hyperinsulinemia, and insulin resistance, and ensuing visible changes on skin which is known as the AN. The purpose of this review was to assess the validity of AN as an early indicator of T2DM. Nineteen articles that were published from 1994 to 2010 were included for this review and reported an association between AN, hyperinsulinemia, and hyperglycemia. Nurses and advanced nurse practitioners working with children and adolescents have a tremendous role in identifying the risk factors, counseling, role modeling, and referring them to available community resources to promote healthy living. Early initiatives focusing on lifestyle changes may halt the progress, chronicity, and burden of T2DM in children and adolescents.

Acanthosis nigricans as a clinical marker to detect insulin resistance in Caucasian children from West Virginia

The accuracy of acanthosis nigrcans (AN) as a dermatological clinical marker to predict insulin resistance (IR) has not been well established in children. A cohort of obese Caucasian children was prospectively recruited. Demographic data, body mass index values, and laboratory data were compared for the presence or absence of AN. A total of 76 children participated. In all, 46 (60.5%) children had AN, and 34 (44.7%) children were positive for IR (>3.16); 25 (32.9%) children were positive for both AN and IR. Sensitivity, specificity, positive and negative predictive values, and accuracy level for AN to detect IR in the obese children who participated in this study were 73.5%, 50%, 54.3%, 70%, and 49%, respectively. The correlation between insulin and fasting glucose levels in AN-negative or AN-positive patients was low (R (2) = 13% to 17%). Acanthosis nigricans was only a surrogate marker for IR. It is concluded that IR should be examined in every obese West Virginian child irrespective of his or her AN status.

Screening obese students for acanthosis nigricans and other diabetes risk factors in the urban school-based health center

OBJECTIVE

To determine the prevalence of acanthosis nigricans (AN) and other diabetes risk factors in urban school health clinics.

METHODS

During the period 2006-2009 nurse practitioners (NPs) screened students who had a BMI ≥ 95th percentile and 1 additional diabetes risk factor. Blood glucose (BG) was measured by finger stick. NPs were trained on how to ascertain the presence of AN on the neck area.

RESULTS

NPs screened 854 students (mean age 11.4 years, 60.5% female, and 73.3% black). AN and elevated BG were found among 26% and 6.4% of students, respectively. Females and minorities were respectively 50% and 4 times more likely to have AN. Youth with AN were twice as likely to have elevated glucose.

CONCLUSION

AN can be easily identified by trained health care professionals even in busy school-based clinic settings. Checking for AN and appropriate education and counseling should become a routine part of electronic documentation in overweight youth.

Acanthosis nigricans and truncal fat in overweight and obese children

BACKGROUND

Screening for acanthosis nigricans (AcN) in overweight children is repeatedly recommended. The significance of AcN, and its relation to central obesity in children, is unclear.

OBJECTIVE

To compare clinical and anthropometric parameters associated with adiposity, between overweight and obese children with and without AcN.

METHODS

One hundred and forty-nine overweight and obese children were screened for AcN. Height, weight, waist and hip circumferences, triceps skinfold thickness and segmental body fat amounts were measured.

RESULTS

Twenty-two (14.8%) children had AcN. Children with AcN had greater height, weight, BMI, waist circumference, waist-to-height-ratio, triceps skinfold thickness, and total and truncal body fat percentage, compared to those without AcN. After adjustment for age and BMI, no adiposity measure was increased in children with AcN.

CONCLUSION

Overweight and obese children with AcN basically have greater overall and central adiposity, than those without it. Adjusting for BMI, there is no evidence for increased abdominal fat in these children.

Body mass index percentile more sensitive than acanthosis nigricans for screening Native American children for diabetes risk

BACKGROUND

Many Native American tribes use acanthosis nigricans to screen for type 2 diabetes risk. We hypothesized that acanthosis nigricans misses many children at risk for type 2 diabetes.

METHODS

We evaluated 5- to 18-year-old Native American children and youth to assess the sensitivity and specificity of acanthosis nigricans as a marker for insulin resistance.

RESULTS

In a cohort of 161 youth (72 males/89 females), mean age was 10.7 years + 3.9. Mean body mass index (BMI) percentile was 76.8 +/- 23.3, and 54% had a BMI at or above the 85th percentile. Acanthosis nigricans was present in 21.7% of the participants and was more common in 12-to 18-year-olds than in 5 to 11-year-olds (p = .02). Of those with acanthosis nigricans, 82.4% had insulin resistance (homeostatic model assessment of insulin resistance >4), but only 48.3% of those with insulin resistance had acanthosis nigricans. In contrast, BMI at or above the 85th percentile had a high sensitivity (74%) for insulin resistance, even though its specificity was lower (58%).

CONCLUSIONS

The presence of acanthosis nigricans alone was a specific, but not a sensitive, screening tool for identifying youth with insulin resistance. BMI at or above the 85th percentile was a more sensitive screening tool than acanthosis nigricans alone, or acanthosis nigricans and BMI together for identifying children and youth with IR who are at increased risk for type 2 diabetes.

Acanthosis nigricans in a patient with lung cancer: a case report

Some skin lesions may accompany malignancies. Acanthosis nigricans, one such lesion, is a paraneoplastic dermatosis characterized by hyperpigmented and velvety verrucose plaques observed as symetric eruptions. With this report, we aim to present a rare case of concomitant lung cancer and acanthosis nigricans. Malignant acanthosis nigricans is most commonly associated with intra-abdominal malignancies. A 65-year-old patient who had hyperpigmented, hypertrophic and symmetric verrucose lesions at the flexor surfaces of the lower and upper extremities, face, palms and the axillary region. Thoracic computed tomography demonstrated a hypodense mass lesion with a dimension of 5 × 5.5 cm at the center of basal segment bronchi of the left pulmonary lobe. Fiberoptic bronchoscopy showed that the access to the lower left lobe was almost completely obstructed by the endobronchial lesion. The result of the histopathologic examination of the endobronchial tissue biopsy was reported as non-small cell (adenocarcinoma) lung cancer. Result of the histopathologic analysis of the punch biopsy of the skin lesions was reported as acanthosis nigricans .There are no pathognomonic dermatological findings for lung cancer. In conclusion, there are skin lesions that accompany lung cancer and we believe that these should be considered for differential diagnosis.

Acanthosis Nigricans: high prevalence and association with diabetes in a practice-based research network consortium--a PRImary care Multi-Ethnic network (PRIME Net) study

BACKGROUND

Previous work has established a surprisingly high prevalence of acanthosis nigricans (AN) and its association with increased risk of type 2 diabetes in a Southwestern practice-based research network (PBRN). Our objective was to establish whether this high prevalence of AN would be present in other areas.

METHODS

We examined the prevalence of type 2 diabetes and its risk factors and the prevalence of AN among patients aged 7 to 65 years who had been seen by one of 86 participating clinicians in a national PBRN consortium during a 1-week data collection period. In a subsample of nondiabetic matched pairs who had or did not have AN, we compared fasting glucose, insulin, and lipid levels.

RESULTS

AN was present in 19.4% of 1730 patients from among all age ranges studied. AN was most prevalent among persons with more risk factors for diabetes. Patients with AN were twice as likely as those without AN to have type 2 diabetes (35.4% vs 17.6%; P < .001). In multivariable analysis, the prevalence ratio for diabetes was 2.1 (95% CI, 1.3-3.5) among non-Hispanic whites with AN and 1.4 (95% CI, 1.1-1.7) among minority patients with AN. In a subsample of 11 matched pairs, those with AN had higher levels of insulin and insulin resistance.

CONCLUSIONS

We found high rates of AN among patients in primary care practices across the country. Patients with AN likely have multiple diabetes risk factors and are more likely to have diabetes.

Acanthosis nigricans among Northern Plains American Indian children

The purpose of this study is to present cross-sectional and prospective data on acanthosis nigricans (AN) prevalence in the context of other risk factors for diabetes including high body mass index (BMI), abnormal blood pressure (BP), physical inactivity and family history of diabetes among Northern Plains American Indian (AI) children. Standardized health measures were collected in 2,520 K-12th-grade AI students for AN, BMI, and BP. Data were also collected on family history of diabetes and physical activity. Approximately, 9.7% of the participants were positive for AN. AN was associated with high BMI, abnormal BP, and diabetes family history. Sports participation was inversely associated with AN. Among children measured the prior year, relative risk (and 95% confidence interval [CI]) for obesity and incident AN was 9.8 (4.2-23.0) compared to normal weight. These findings suggest there is utility in measuring this marker of insulin resistance in this at-risk population.

A Comparison of Blood Pressure, Body Mass Index, and Acanthosis Nigricans in School-Age Children

The purpose of this retrospective quantitative study was to examine the relationships among acanthosis nigricans (AN), body mass index (BMI), blood pressure (BP), school grade, and gender in children attending elementary school located in South West Texas. Data were collected by attending school district nurses. Researchers reviewed 7,026 previously collected records from a state mandated public school health screening program in elementary school Grades 3, 5, 7, and 9, conducted by school nurses. Of 7,026 records, 6,867 were included for the secondary analysis. A logistic regression analysis was carried out with the AN marker as the dependant variable and school grade, gender, BMI, and BP as the independent variables. The results of the study suggest that a direct relationship exists between the AN marker, BMI, and BP in school-age children. Further study is warranted based on the number of school-age children who are now found to be obese.

Acanthosis nigricans identifies youth at high risk for metabolic abnormalities

OBJECTIVE

To determine the prevalence of abnormal glucose homeostasis and cardiovascular risk factors in youth with acanthosis nigricans (AN).

STUDY DESIGN

Youth (8-14 years) were recruited from community pediatric offices. Each subject underwent a questionnaire, a targeted physical examination, and an oral glucose tolerance test.

RESULTS

Subjects (n = 236) with AN of the neck (AN+) (60% Hispanic, 30% African American, 54% female, body mass index [BMI] z-score 2.3 kg/m(2)) and 51 youth without AN (65% Hispanic, 22% African American, 37% female, BMI z-score 2.1 kg/m(2)) completed the study. Twenty-nine percent of the AN+ group had abnormal glucose homeostasis, 27% had systolic blood pressure > 95th percentile, and 50% had high-density lipoprotein-cholesterol < or =5th percentile. Once corrected for sex, puberty, maternal education, and BMI z-score, AN remained significantly associated with insulin resistance and abnormal glucose homeostasis. For youth in the AN+ group, homeostasis model assessment of insulin resistance, female sex, and positive glutamic acid decarboxylase antibodies remained significantly and independently associated with impaired glucose tolerance.

CONCLUSIONS

Youth in the AN+ group had severe insulin resistance, and more than 1 in 4 already had abnormal glucose homeostasis. AN identified a high-risk population, for whom appropriate interventions have the potential to attenuate or even prevent the development of diabetes and further metabolic abnormalities.

Alterations of carbohydrate and lipoprotein metabolism in childhood obesity--impact of insulin resistance and acanthosis nigricans

AIM

To study the prevalence of alterations of glucose and lipoprotein metabolism and the impact of acanthosis nigricans (AN) in childhood obesity.

PATIENTS AND METHODS

113 obese children, 57 with simple obesity (SO) and 58 with obesity and AN (OAN). Oral glucose tolerance test was performed, serum glucose, insulin and lipoprotein parameters were determined, and insulin resistance/sensitivity indices were calculated.

RESULTS

Insulin resistance, basal and reactive hyperinsulinemia, impaired glucose tolerance (IGT) and dyslipidemia were found to be frequent conditions in children with OS as well as OAN. Reactive insulinemia was more pronounced in OAN than in SO, and insulin resistance was more frequent when AN was more prominent. Triglycerides were higher and HDL-C was lower, and atherogenic dyslipidemia was more frequent in OAN compared to SO.

CONCLUSION

Children with obesity form a risk population. AN is a factor which can be used in metabolic risk factor clustering estimation in childhood obesity.

Metabolic syndrome in fifth grade children with acanthosis nigricans: results from the CARDIAC project

BACKGROUND

A number of cardiovascular disease (CVD) risk factors have been linked to obesity and associated negative health outcomes in children. However, no consistent definition of metabolic syndrome exists for children. In addition, research is needed to systematically examine the prevalence of metabolic syndrome in high-risk children, including those with insulin resistance. This study explores several definitions of metabolic syndrome and determines the prevalence of metabolic syndrome in a large sample of children with acanthosis nigricans (AN).

METHODS

The study used results from a large-scale screening of fifth-grade students in West Virginia to explore the prevalence of metabolic syndrome among 676 male and female participants who had mild to severe AN.

RESULTS

In this high-risk sample of students who had AN, 49% met the criteria, i.e., three risk factors including insulin resistance, high body-mass index, and elevated blood pressure or dyslipidemia, when tested for metabolic syndrome. Children with AN who were classified as obese or morbidly obese were at significantly increased odds of having metabolic syndrome.

CONCLUSIONS

Results are discussed in terms of systematically defining metabolic syndrome for high-risk children, as well as public health and clinical interventions targeting children who are overweight or obese. The presence of AN and morbid obesity might be easily observed markers for metabolic syndrome.

Insulin resistance and impaired glucose tolerance in overweight and obese Costa Rican schoolchildren

BACKGROUND

Worldwide obesity has become an unprecedented public health challenge. In addition, a notable increase in the risk of insulin resistance and type 2 diabetes mellitus has emerged. In Costa Rica, there are no epidemiological data to establish the prevalence of type 2 diabetes in the pediatric population. However, information from the Endocrinology Department of the Children's National Hospital indicates an increased number of cases in the last 2 to 3 years.

OBJECTIVE

To determine the prevalence of insulin resistance and impaired glucose tolerance in overweight and obese schoolchildren.

METHODS

This cross-sectional study was conducted among 214 healthy 8- to 10-year-old children from urban schools of San José, Costa Rica. Anthropometric measurements and blood determinations of glucose, insulin, proinsulin, glycosylated hemoglobin, C-peptide, and leptin were performed. Indexes were calculated to assess insulin resistance. Information on social and lifestyle variables was obtained from questionnaires, and acanthosis nigricans was certified by a physician. Statistical analysis was performed with SPSS software for Windows, version 10.0.

RESULTS

The prevalence of type 2 diabetes mellitus was very low (0.5%) in the studied population. However, hyperinsulinemia and impaired glucose tolerance were present in 20.6% and 6.5% of the subjects, respectively. On the basis of the Fasting Glucose-to-Insulin Resistance Ratio (FGIR), 46.7% of the children showed insulin resistance. Girls and obese children (body mass index > or = 95th percentile) were more likely to have higher serum insulin levels and insulin resistance than boys and overweight children (BMI > or = 85th percentile). Compared with the lowest quintile, children in the highest quintile of body-fat tissue had higher insulin resistance but had similar serum concentrations of glucose, C-peptide, and proinsulin. Positive family histories of type 2 diabetes mellitus and sedentarism (73.7% and 40.7%, respectively) were highly prevalent among overweight and obese children.

CONCLUSIONS

The prevalence of impaired glucose tolerance and insulin resistance in obese children indicates a worrisome trend in the incidence of type 2 diabetes in Costa Rica. Strategies for weight reduction, obesity prevention, and promotion of healthy lifestyles are necessary to prevent the onset of type 2 diabetes during childhood and adolescence.

Prevalence of acanthosis nigricans in relation to anthropometric measures: community-based cross-sectional study in Korean pre-adolescent school children

BACKGROUND

This cross-sectional study was performed to assess the prevalence of acanthosis nigricans (AN) across various anthropometric measures and to identify the cut-offs for anthropometric indices of adiposity for development of AN in Asian preadolescent school children.

METHODS

Body mass index (BMI), percentage weight for height (PWH), percentage body fat (PBF), and AN of the neck were evaluated in children in the fifth grade of all elementary schools in one metropolitan, Korean city (2117 boys and 1916 girls, mean age 10.9 +/- 0.6 years, mean BMI 18.6 +/- 3.3 kg/m(2)).

RESULTS

The prevalence of AN was 8.4% in boys and 5.1% in girls, and was proportional to the BMI, PWH, and PBF. The prevalence of AN rose steeply in the 80th and 90th percentiles of the BMI, PWH, and PBF in boys and girls, respectively. According to receiver operating characteristic analysis, AN was observed in boys with BMI >22.2 kg/m(2), and in girls with BMI >21.2 kg/m(2), which are below the current criteria for childhood obesity (local BMI 95th percentile and International Obesity Task Force BMI 30 kg/m(2)).

CONCLUSIONS

AN has a good correlation with level of adiposity, and was already present in overweight children that were not considered obese by definition.

Insulin-like growth factor-I is inversely related to adiposity in overweight Latino children

The purpose of this study was to examine interrelationships between IGF-I, IGF binding proteins (IGFBPs) and adiposity in 178 overweight Hispanic adolescents (11.2 +/- 1.7 yr; body mass index: 28.2 +/- 5.4 kg/m2). Immunoradiometric assays were used to measure IGF-I, IGFBP-1 and IGFBP-3. Total fat and lean tissue mass were measured by DEXA and visceral and subcutaneous adipose tissue by MRI. IGF-I and IGFBP-3 remained inversely correlated with total body fat mass (r = -0.52, p < 0.001 and r = -0.25, p < 0.01, respectively) after controlling for covariates. IGFBP-1 was inversely correlated to total fat mass (r = -0.55, p < 0.001) in simple correlations; however, this relationship was eliminated after controlling for covariates (r = 0.02, p = 0.85). Correlations with visceral and subcutaneous adipose tissue yielded similar results. These results demonstrate that IGF-I, IGFBP-1 and IGFBP-3 are all inversely related to adiposity in Hispanic children.

Metabolic risk-factor clustering estimation in children: to draw a line across pediatric metabolic syndrome

BACKGROUND

The diagnostic criteria of the metabolic syndrome (MS) have been applied in studies of obese adults to estimate the metabolic risk-associated with obesity, even though no general consensus exists concerning its definition and clinical value. We reviewed the current literature on the MS, focusing on those studies that used the MS diagnostic criteria to analyze children, and we observed extreme heterogeneity for the sets of variables and cutoff values chosen.

OBJECTIVES

To discuss concerns regarding the use of the existing definition of the MS (as defined in adults) in children and adolescents, analyzing the scientific evidence needed to detect a clustering of cardiovascular risk-factors. Finally, we propose a new methodological approach for estimating metabolic risk-factor clustering in children and adolescents.

RESULTS

Major concerns were the lack of information on the background derived from a child's family and personal history; the lack of consensus on insulin levels, lipid parameters, markers of inflammation or steato-hepatitis; the lack of an additive relevant effect of the MS definition to obesity per se. We propose the adoption of 10 evidence-based items from which to quantify metabolic risk-factor clustering, collected in a multilevel Metabolic Individual Risk-factor And CLustering Estimation (MIRACLE) approach, and thus avoiding the use of the current MS term in children.

CONCLUSION

Pediatricians should consider a novel and specific approach to assessing children/adolescents and should not simply derive or adapt definitions from adults. Evaluation of insulin and lipid levels should be included only when specific references for the relation of age, gender, pubertal status and ethnic origin to health risk become available. This new approach could be useful for improving the overall quality of patient evaluation and for optimizing the use of the limited resources available facing to the obesity epidemic.

Adipose tissue and liver lipid metabolism in obese children: role of the body mass index and the presence of acanthosis nigricans

AIMS

The aims of our study were to determine if insulin resistance is associated with increased plasma levels of non-esterified fatty acids (NEFA), glycerol, 3-hydroxybutyrate and triglycerides in obese children. We also studied whether the presence of acanthosis nigricans (AN) led to further alterations in the above parameters.

METHODS

A total of 101 children were studied on their first visit to the paediatric endocrine clinic. Seventy-four were obese, 30 of them with AN. The remaining 27 were non-obese healthy children (control group). NEFAs, glycerol, triglycerides, 3-hydroxybutyrate, insulin, leptin, adiponectin and glucose were determined in blood samples obtained after overnight fasting. The insulin resistance index (IRI) was calculated following the homeostasis model assessment (HOMA). Data from the three groups were compared using appropriate statistical tests.

RESULTS

No differences in age, sex ratio and pubertal stage were observed among the three groups. The group of children with the highest body mass index (BMI) showed higher plasma levels of insulin and leptin, higher IRI and lower plasma levels of adiponectin. As insulin and IRI increased, NEFA and 3-hydroxybutyrate decreased and triglycerides increased. When obese children were categorized by BMI, the presence of AN further exacerbated these differences.

CONCLUSIONS

In obese children, insulin resistance is associated with plasma lipid alterations suggestive of both decreased adipose tissue lipolysis and hepatic beta-oxidation and increased hepatic synthesis of triglycerides. Such a metabolic condition may facilitate fat storage and hinder weight loss.

Juvenile acanthosis nigricans

Acanthosis nigricans is a velvety thickening of the epidermis that primarily affects the axillae, posterior neck fold, flexor skin surfaces, and umbilicus, and infrequently is diffuse with involvement of the mucosal surfaces. It is increasingly seen in children and adolescents who are obese, and can serve as a cutaneous marker of insulin resistance and malignancy. Although malignancy-associated acanthosis nigricans is rare in the pediatric population, one need be concerned about its association with certain pediatric syndromes. More importantly, insulin resistance itself can also represent a threat to life. We review this important disorder.

Acanthosis nigricans and diabetes risk factors: prevalence in young persons seen in southwestern US primary care practices

PURPOSE

Evidence shows acanthosis nigricans is often associated with hyperinsulinemia and may indicate increased risk of type 2 diabetes mellitus. The purpose of this study was to determine the association of acanthosis nigricans with type 2 diabetes risk factors and disease in young persons.

METHODS

We conducted a cross-sectional study in the Research in Outpatient Settings Network, a practice-based research network in southwestern US communities. Participating clinicians (N = 96) collected data on children and young adults aged 7 to 39 years seen during a 2-week sampling period. The main outcomes were the prevalence of acanthosis nigricans, type 2 diabetes risk factors (ethnicity, family history of type 2 diabetes, hypertension, overweight/obesity), type 2 diabetes, and the relationships among these.

RESULTS

Among 1,133 patients sampled, risk factors for type 2 diabetes were common: 69% had a family history of the disease; 3% of children (aged 7 to 19 years) and 12% of adults had hypertension; 43% of children and 73% of adults were overweight or obese; and 80% were members of ethnic minorities. Acanthosis nigricans was found in 17% of children and 21% of adults. Among children and adults alike, the more type 2 diabetes risk factors that were present, the higher the prevalence of acanthosis nigricans (P <.001). The prevalence ratio for type 2 diabetes in patients with acanthosis nigricans was 1.97 (95% confidence interval, 1.18-3.27; P = .01) after controlling for age, body mass index, and the number of type 2 diabetes risk factors. Clinicians reported that the identification of acanthosis nigricans frequently led to discussions about lifestyle modification for decreasing the risk of type 2 diabetes.

CONCLUSIONS

Patients with acanthosis nigricans are likely to have multiple risk factors for type 2 diabetes. Acanthosis nigricans may be an independent risk factor for this disease. Detection of acanthosis nigricans may help clinicians more rapidly identify high-risk individuals for diabetes counseling.

Acanthosis Nigricans in Patients with Nonalcoholic Steatohepatitis: An Uncommon Finding

OBJECTIVE

To determine the prevalence and the metabolic characteristics of acanthosis nigricans (AN) in a group of 28 study subjects with biopsy-proven nonalcoholic steatohepatitis (NASH).

METHODS

The study participants (15 female and 13 male patients, 20 of whom were white subjects; mean body mass index, 32.7 +/- 5.7 kg/m2; mean age, 45.7 +/- 11.3 years) underwent an oral glucose tolerance test (OGTT), frequently sampled intravenous glucose tolerance test (FSIGT), and fasting metabolic panels. AN status was clinically determined, and fat mass was measured by dual-energy x-ray absorptiometry.

RESULTS

All study subjects had insulin resistance (IR), and 15 (54%) had the metabolic syndrome (by Adult Treatment Panel III criteria). Of the 28 patients, 4 (14%) had AN (AN+) and 24 did not (AN-). AN+ subjects had a higher body mass index (37.7 +/- 5.6 versus 31.5 +/- 4.3 kg/m2), fat mass (38.9 +/- 4.0 versus 29.2 +/- 2.3 kg), and leptin levels (17.2 +/- 3.9 versus 9.3 +/- 1.6 ng/mL) (P<0.05). They also had significantly higher indices of insulin secretion: fasting and stimulated insulin and C-peptide levels from OGTT and FSIGT. Metabolic syndrome prevalence was 40% in AN- versus 75% in AN+ subjects (not significantly different). Although the AN+ group had significantly lower fasting and OGTT-derived indices of insulin sensitivity in comparison with the AN- group, their FSIGT indices were similar. Waist circumference (a surrogate of visceral adiposity) and cytokine profiles were similar in the AN+ and AN- groups.

CONCLUSION

AN was not highly prevalent in our study cohort with NASH, despite the high prevalence of IR. Hyperinsulinemia and total adiposity, rather than visceral adiposity and IR, were the indices most predictive of AN. The use of AN as an index of IR in patients with NASH appears to have limited diagnostic value.