Prevalence of insulin resistance and impaired glucose tolerance in a sample of obese Spanish children and adolescents

Studies in children with obesity in two European treatment centres show a high prevalence of impaired glucose metabolism in the Swedish cohort

AIM

To investigate the prevalence and possible risk factors for the development of impaired glucose metabolism in children and adolescents with obesity.

METHODS

This was a cross-sectional retrospective cohort study, including 634 patients with obesity and 98 normal weight controls aged 4-18 years from the Beta-cell function in Juvenile Diabetes and Obesity (Beta-JUDO) cohort, a dual-centre study at Uppsala University Hospital (Sweden) and Paracelsus Medical University Hospital (Salzburg, Austria) conducted between 2012 and 2021. A longitudinal subgroup analysis, including 188 of these subjects was performed. Impaired glucose metabolism was diagnosed by oral glucose tolerance tests according to American Diabetes Association criteria.

RESULTS

The prevalence of impaired glucose metabolism was 72% in Uppsala patients, 24% in Salzburg patients, 30% in Uppsala controls and 13% in Salzburg controls. The prevalence was lower at the follow-up visits compared with baseline both in Uppsala and Salzburg patients. A family history of type 2 diabetes showed the strongest association with impaired glucose metabolism at the follow-up visits besides belonging to the Uppsala cohort.

CONCLUSION

The prevalence of impaired glucose metabolism was extraordinarily high in Swedish children and adolescents with obesity, but decreased during the follow-up period.

The impact of obesity epidemic on type 2 diabetes in children and adolescents: A systematic review and meta-analysis

AIM

To assess the impact of the obesity epidemic on type 2 diabetes (T2D), prediabetes and glycometabolic indices in children and adolescents.

METHODS

We searched four electronic databases (PubMed, Embase, Cochrane and Web of Science). Cross-sectional or cohort studies that reported on obesity and the prevalence of T2D or prediabetes in children and adolescents were reviewed. The study design, sample size and clinical outcomes were extracted from each study. The prevalence of T2D and prediabetes from the studies were pooled using meta-analysis methods.

RESULTS

Meta-analysis of 228184 participants showed that the prevalence of T2D was 1.3% (95% confidence interval (CI), 0.6-2.1%) in obese subjects, which was 13 times that in normal weight subjects (0.1%, 95% CI, 0.01-0.2%). The prevalence of prediabetes in obese subjects was 3 times that in normal subjects at 17.0% (13.0-22.0%) vs. 6.0% (0.01-11.0%). Moreover, BMI was positively correlated with the prevalence of T2D, prediabetes and glycometabolic indices in obese children and adolescents.

CONCLUSION

The pooled results confirm that obesity in children and adolescents leads to statistically significant increases in the prevalence of T2D and prediabetes and in glycometabolic indicator levels.

The effects of diet quality and dietary acid load on insulin resistance in overweight children and adolescents

INTRODUCTION

This study aimed to investigate the association of diet quality (DQ) and dietary acid load (DAL) with insulin resistance (IR) in overweight children and adolescents.

MATERIALS AND METHODS

The study was conducted on 135 overweight participants aged 6-17 years. DQ was assessed using the Healthy Eating Index 2015 (HEI-2015) and the HEI-2015-TUBER, revised in accordance with the Turkey Dietary Guidelines (TUBER). Estimation of DAL was made calculating the potential renal acid load (PRAL) and net endogenous acid production (NEAP) scores.

RESULTS

The HEI-2015-TUBER score was lower in those with IR than in those without IR (p=0.021). Higher PRAL and NEAP scores were found in those with IR (p=0.060 and p=0.044, respectively). Moreover, a one-unit increase in the HEI-2015-TUBER score and the DAL score was associated with a reduction of 4.2% and a rise of approximately 3% in IR risk, respectively.

CONCLUSIONS

Healthy eating habits in overweight paediatric groups may help to reduce the IR risk, improving DQ and decreasing DAL.

Prevalence of different states of glucose intolerance in Sri Lankan children and adolescents with obesity and its relation to other comorbidities

BACKGROUND

South Asian adults have higher prevalence of obesity comorbidities than other ethnic groups. Whether this also is true for Sri Lankan children with obesity has rarely been investigated.

OBJECTIVE

To investigate prevalence of glucose intolerance and other comorbidities in Sri Lankan children with obesity and compare them with Swedish children. To identify risk factors associated with glucose intolerance.

SUBJECTS

A total of 357 Sri Lankan children (185 boys), aged 7 to 17 years with BMI-SDS ≥2.0 from a cross-sectional school screening in Negombo. A total of 167 subjects from this study population were matched for sex, BMI-SDS and age with 167 Swedish subjects from the ULSCO cohort for comparison.

METHODS

After a 12 hour overnight fast, blood samples were collected and oral glucose tolerance test was performed. Body fat mass was assessed by bioelectrical impedance assay. Data regarding medical history and socioeconomic status were obtained from questionnaires.

RESULTS

Based on levels of fasting glucose (FG) and 2 hours-glucose (2 hours-G), Sri Lankan subjects were divided into five groups: normal glucose tolerance (77.5%, n = 276), isolated impaired fasting glucose according to ADA criteria (9.0%, n = 32), isolated impaired glucose tolerance (8.4%, n = 30), combined impaired fasting glucose (IFG) + impaired glucose tolerance (IGT) (3.1%, n = 11) and type 2 diabetes mellitus (2.0%, n = 7). FG, 2 hours-insulin and educational status of the father independently increased the Odds ratio to have elevated 2 hours-G. Sri Lankan subjects had higher percentage of body fat, but less abdominal fat than Swedish subjects.

CONCLUSION

High prevalence in Sri Lankan children with obesity shows that screening for glucose intolerance is important even if asymptomatic.

Implications of visfatin genetic variants in the metabolic profile of the Romanian pediatric population

Background: Conflictual results regarding the relationship between plasmatic level of visfatin and obesity could be explained by the influence of the gene variants involved in the synthesis or action of these hormones.

Objectives: The present study examined the potential implication of single nucleotide polymorphisms (SNPs) of nicotinamide phosphoribosyltransferase (NAMPT) gene that encodes visfatin, in obesity, in a Romanian pediatric population.

Method: A case-control study was conducted on a group of 213 children, divided into two: the case group - 130 overweight and obese children with BMI >1 SD, and the control group - 83 children with normal BMI. The variables analyzed were age, sex, anthropometric parameters, body composition based on bioimpedance analysis, lipid profile, visfatin and insulin plasmatic levels, rs4730153 and rs2302559 visfatin SNPs.

Results: Significant associations were not found between rs4730153 and rs2302559 visfatin SNPs and obesity. Regarding lipid metabolism, there are statistically significant differences between triglyceride levels according to NAMPT rs2302559 genotypes (p=0.045), with heterozygous genotype having the highest level of triglycerides, and also between cholesterol levels according to NAMPT rs4730153 genotypes (p=0.030), with carriers of heterozygote genotype having the highest level of cholesterol. There is a statistically significant difference between the studied parameters in the investigated groups, regarding cholesterol, in carrier of wild-type genotype of NAMPT rs2302559 (p=0.040) and carrier of wild-type genotype of NAMPT rs4730153 (p=0.036). We observed no association of NAMPT rs4730153 and rs2302559 with visfatin levels in the studied groups. Visfatin level was lower in the case group and was correlated with weight (p=0.042), abdominal circumference (p=0.010), waist to height ratio (p=0.040), but not with the elements of the metabolic profile.

Conclusion: NAMPT rs2302559 and rs4730153 polymorphisms do not seem to have a major impact in the development of obesity in children, however there may be an association with lipid profile, but further studies are needed..

Changes in insulin sensitivity over time and associated factors in HIV-infected adolescents

OBJECTIVE

To compare prevalence of insulin resistance between perinatally HIV-infected (PHIV+) and perinatally HIV-exposed, but uninfected adolescents (PHEU), determine incidence of and contributory factors to new and resolved cases of insulin resistance in PHIV+, and evaluate glucose metabolism.

DESIGN

Cross-sectional design for comparison of prevalence among PHIV+ and PHEU. Longitudinal design for incidence and resolution of insulin resistance among PHIV+ at risk for these outcomes.

METHODS

The source population was adolescents from pediatric HIV clinics in the United States and Puerto Rico participating in the Pediatric HIV/AIDS Cohort Study, an ongoing prospective cohort study designed to evaluate impact of HIV infection and its treatment on multiple domains in preadolescents and adolescents. Insulin resistance was assessed by homeostatic model assessment of insulin resistance. Those with incident insulin resistance underwent 2-h oral glucose tolerance test and HbA1c. Baseline demographic, metabolic, and HIV-specific variables were evaluated for association with incident or resolved insulin resistance.

RESULTS

Unadjusted prevalence of insulin resistance in PHIV+ was 27.3 versus 34.1% in PHEU. After adjustment for Tanner stage, age, sex, and race/ethnicity, there was no significant difference between groups. Factors positively associated with developing insulin resistance included female sex, higher BMI z score, and higher waist circumference; those associated with resolving insulin resistance included male sex and lower BMI z score.

CONCLUSION

Prevalence of insulin resistance in PHIV+ and PHEU was substantially higher than that reported in HIV-uninfected nonoverweight youth, but similar to that in HIV-uninfected obese youth. Factors associated with incident or resolved insulin resistance among PHIV+ were similar to those reported in HIV-negative obese youth. However, a contributory role of HIV infection and/or its treatment to the incident risk of insulin resistance cannot be excluded.

Insulinaemia and insulin resistance in Caucasian general paediatric population aged 2 to 10 years: Associated risk factors

BACKGROUND

The aim of this study is to determine values of insulinaemia, homeostasis model assessment (HOMA) index and quantitative insulin sensitivity check index (QUICKI) among a population of prepubertal Caucasian children, to analyse factors associated with insulin resistance (IR), and to study its association with cardiovascular risk factors.

MATERIALS AND METHODS

Population-based study conducted on a randomly selected sample of prepubescent Caucasian subjects aged 2.00 to 9.99 years old. Anthropometric measurements, blood pressure, and fasting blood samples were obtained, including fasting glucose, triglycerides, High Density Lipoprotein (HDL)-cholesterol, and insulin. In addition, QUICKI and HOMA indices were calculated. Generalised additive models for location, scale and shape (GAMLSS) was used to calculate centiles curves and multivariate logistic regression analysis to assess factors associated with IR.

RESULTS

A total of 654 subjects were included. Mean values obtained for insulinaemia, HOMA index, and QUICKI were 3.74 μIU/mL, 0.73, and 0.44, respectively, in the overall population and 3.32 μIU/mL, 0.64 and 0.46, respectively, in normal weight subjects. The main factor associated with IR was abdominal obesity (odds ratio [OR] 3.38 [95% CI 1.44-7.94] in the subgroup aged 2.00-5.99 years and OR 9.14 [3.42-24.41] for those aged 6.00-9.99 years). An increased risk of hyperglycaemia (P = 0.043), hypertriglyceridaemia (P < .001), and HDL < p10 (P = 0.021) was described among children aged 2.00 to 5.99 years with IR, and among those aged 6.00 to 9.99 years, IR was associated with an increased risk of hypertriglyceridaemia (P < .001).

CONCLUSION

Abdominal obesity was the main factor associated with IR. Metabolic changes associated with IR seem to be present from early stages of life, which highlights the importance of the prevention, early diagnosis and treatment of obesity.

Assessment of HOMA1-IR, Matsuda and ISSI-2 indices in relation to the metabolic syndrome features and oral glucose tolerance test in young people

<I>Background:</I> Insulin resistance and reduced ability of pancreatic beta cells to secrete insulin preside carbohydrate disorders development and this condition is one of the stages in the type 2 diabetes development. Indirect indices of insulin resistance, sensitivity and pancreatic beta cells function, are used in clinical practice. They are calculated based on glucose and insulin concentration under fasting and postprandial condition. <I>Aim:</I> The aim of this study was to examine relationship between HOMA1-IR, Matsuda Index, and ISSI-2 with metabolic syndrome (MS) features and shape of glycemic curve in young, potentially healthy people. <i>Material and method:</i> The study group consisted of 152 volunteers (108 women, 44 men) aged 19-28. Participants underwent the questionnaire, anthropometric and arterial blood pressure examination. In blood samples under fasting condition lipid profiles, glucose, and insulin were measured. Glucose and insulin were measured also in 60 and 120 minutes of Oral Glucose Tolerance Test (OGTT). Based on the results, MS features were identified and HOMA1-IR, Matsuda Index and ISSI-2 values were calculated. <I>Results:</I> The value of HOMA1-IR was significant higher in patients with metabolic syndrome while lower values of Matsuda and ISSI-2 were observed in participants with the MS as well as with glucose concentration in 120-minute of OGTT higher than under fasting condition. <i> Conclusions:</i> MS is associated with an increase in hepatic insulin resistance. Both MS and retardation of glucose returning to fasting values during OGTT are related to peripheral insulin resistance and reduction of pancreatic beta cell ability to insulin secretion.

Lower Frequency of HLA-DRB1 Type 1 Diabetes Risk Alleles in Pediatric Patients with MODY

Objective

The aim of this study was to determine the frequency of susceptible HLA-DRB1 alleles for type 1 diabetes in a cohort of pediatric patients with a confirmed genetic diagnosis of MODY.

Materials and Methods

160 families with a proband diagnosed with type 1 diabetes and 74 families with a molecular diagnosis of MODY (61 GCK-MODY and 13 HNF1A-MODY) were categorized at high definition for HLA-DRB1 locus. According to the presence or absence of the susceptible HLA-DRB1 alleles for type 1 diabetes, we considered three different HLA-DRB1 genotypes: 0 risk alleles (no DR3 no DR4); 1 risk allele (DR3 or DR4); 2 risk alleles (DR3 and/or DR4).

Results

Compared with type 1 diabetes, patients with MODY carried higher frequency of 0 risk alleles, OR 22.7 (95% CI: 10.7–48.6) and lower frequency of 1 or 2 risk alleles, OR 0.53 (95% CI: 0.29–0.96) and OR 0.06 (95% CI: 0.02–0.18), respectively.

Conclusions

The frequency of HLA-DRB1 risk alleles for type 1 diabetes is significantly lower in patients with MODY. In children and adolescents with diabetes, the presence of 2 risk alleles (DR3 and/or DR4) reduces the probability of MODY diagnosis, whereas the lack of risk alleles increases it. Therefore, we might consider that HLA-DRB1 provides additional information for the selection of patients with high probability of monogenic diabetes.

Insulin resistance in obese children and adolescents

OBJECTIVE

To evaluate the presence of insulin resistance and its association with other metabolic abnormalities in obese children and adolescents.

METHODS

Retrospective study of 220 children and adolescents aged 5-14 years. Anthropometric measurements were performed (weight, height, and waist circumference) and clinical (gender, age, pubertal stage, and degree of obesity) and biochemical (glucose, insulin, total cholesterol, and fractions, triglycerides) data were analyzed. Insulin resistance was identified by the homeostasis model assessment for insulin resistance (HOMA-IR) index. The analysis of the differences between the variables of interest and the HOMA-IR quartiles was performed by ANOVA or Kruskal-Wallis tests.

RESULTS

Insulin resistance was diagnosed in 33.20% of the sample. It was associated with low levels of high-density lipoprotein cholesterol (HDL-C; p=0.044), waist circumference measurement (p=0.030), and the set of clinical and metabolic (p=0.000) alterations. Insulin-resistant individuals had higher mean age (p=0.000), body mass index (BMI; p=0.000), abdominal circumference (p=0.000), median triglycerides (p=0.001), total cholesterol (p≤0.042), and low-density lipoprotein cholesterol (LDL-C; p≤0.027); and lower HDL-C levels (p=0.005). There was an increase in mean BMI (p=0.000), abdominal circumference (p=0.000), and median triglycerides (p=0.002) as the values of HOMA -IR increased, with the exception of HDL-C, which decreased (p=0.001). Those with the highest number of simultaneous alterations were between the second and third quartiles of the HOMA-IR index (p=0.000).

CONCLUSION

The results confirmed that insulin resistance is present in many obese children and adolescents, and that this condition is associated with alterations that represent an increased risk for developing metabolic disorders in adulthood.

Increased leptin/adiponectin ratio and free leptin index are markers of insulin resistance in obese girls during pubertal development

BACKGROUND

Modifications in body fat in obese patients during puberty determine changes in adipokines that affect insulin sensitivity.

AIMS

We hypothesized that the leptin/adiponectin (L/A) ratio and free leptin index (FLI) are good markers of insulin resistance (IR) and total body fat (TBF) during pubertal development.

METHODS

A prospective study of 32 obese girls (OG) and age-matched control girls (CG) was performed. OG were divided into those that maintained a weight loss (WL) of >1 SD of initial body mass index (BMI) (WL group, n = 25) and those without WL (NWL group, n = 7). Oral glucose tolerance tests (OGTT) were performed to evaluate IR. Correlations of adipokines, L/A, and FLI with BMI, waist circumference, percentage of TBF (%TBF) and IR were performed over pubertal development.

RESULTS

The L/A ratio and FLI were increased in OG at baseline. Both indexes decreased in the WL group as puberty progressed, with no change in CG or NWL. In the WL group, a correlation between L/A and FLI with OGTT and %TBF, and L/A and homeostasis model assessment (HOMA) was found throughout the study.

CONCLUSION

The L/A ratio and FLI are good markers to follow changes in IR and %TBF after WL during puberty. Insulin more accurately reflects the changes in IR than HOMA.

Association of the apolipoprotein b/apolipoprotein a-I ratio, metabolic syndrome components, total cholesterol, and low-density lipoprotein cholesterol with insulin resistance in the population of georgia

The study was designed to assess the association between insulin resistance (IR) and apolipoprotein B/apolipoprotein A-I ratio (ApoB/ApoA-I ratio), metabolic syndrome (MetS) components, total cholesterol (TC), and low-density lipoprotein cholesterol (LDL-C) in the nondiabetic population of Georgia. The subjects were 1522 Georgians of Caucasian origin (mean age = 45 years, 653 women) without diabetes who had visited the clinics for a related health checkup between 2012 and 2013. IR was calculated using the computer homeostasis model assessment (HOMA2-IR) and was defined as the upper quartile. MetS was diagnosed using the updated ATP-III definition of the metabolic syndrome. Logistic and multiple regression models were used to estimate the association between IR and other components. IR was positively correlated with age, ApoB, ApoB/ApoA-I ratio, MetS components (excluding high-density lipoprotein cholesterol-HDL-C), LDL-C, fasting insulin, and TC and negatively correlated with HDL-C and ApoA-I in both sexes (all P < 0.001). In the logistic regression models, gender, age, ApoB/ApoA-I ratio, diastolic pressure, HDL-C, LDL-C, fasting glucose, and triglycerides were the covariates significantly associated with IR (OR: 8.64, 1.03, 17.95, 1.06, 0.13, 1.17, 3.75, and 2.29, resp.; all P < 0.05). Multiple regression models demonstrated that these components (except for HDL-C) made an independent contribution to the prediction of HOMA2 (all P < 0.05).

Adiposity and glucose intolerance exacerbate components of metabolic syndrome in children consuming sugar-sweetened beverages: QUALITY cohort study

BACKGROUND

Sugar-sweetened beverage (SSB) consumption is linked to weight gain and metabolic syndrome (MetS) components in children, but whether these associations are modified by excess weight and glucose tolerance status in children is not known.

OBJECTIVE

The objective of this study was to examine the cross-sectional associations between SSB intake and MetS components among children above and below the 85th body mass index (BMI) percentile and those with and without impaired glucose tolerance (IGT).

METHODS

Data were from the QUébec Adiposity and Lifestyle InvesTigation in Youth study (2005-2008). Caucasian children aged 8-10 years (n = 632) were recruited from 1040 primary schools in Québec, Canada. SSB consumption was assessed by three 24-h dietary recalls, body fat mass by dual-energy absorptiometry, physical activity by 7-d accelerometer. Multivariate linear regressions were used, with age, sex, fat mass index and physical activity as covariates, including waist circumference (WC), systolic blood pressure (SBP), concentrations of triglyceride and high-density lipoprotein cholesterol and homeostasis model assessment of insulin resistance (HOMA-IR) as outcome variables.

RESULTS

Among overweight children, a 100-mL higher SSB consumption was associated with a 0.1-unit higher HOMA-IR (P = 0.009) and a 1.1-mm Hg higher SBP (P = 0.001). In children with IGT, a 100-mL higher SSB consumption was associated with a 1.4-mm Hg higher SBP and a 4.0-cm higher WC (P < 0.001). These associations were not observed among children <85th BMI percentile.

CONCLUSIONS

Our results suggest that the association between higher SSB consumption and MetS components is more evident in overweight/obese and glucose-intolerant children.

Changes in ghrelin and asymmetrical dimethylarginine in obese Mexican adolescents after six-month lifestyle intervention

The aim of this study was to evaluate the effect of a six-month lifestyle intervention on ghrelin and asymmetrical dimethylarginine (ADMA) in obese Mexican adolescents. A total of 65 obese Mexican adolescents aged 10-16 years completed a six-month lifestyle intervention. Anthropometric and biochemical parameters were assessed at baseline and at six months. Twenty normal-weight adolescents were also evaluated at baseline. Insulin resistance (IR) was determined by the homeostasis model assessment of IR (HOMA-IR). Ghrelin and ADMA were determined by enzyme-linked immunosorbent assay. Obese adolescents presented significantly higher triglycerides, cholesterol, glucose, insulin, HOMA-IR, and ADMA levels, while ghrelin was significantly lower. The lifestyle intervention led to a significant improvement in HOMA-IR, ghrelin, and ADMA in the whole studied obese subjects. ADMA and ghrelin levels were associated with BMI and IR components. According to the value of HOMA-IR, the obese subjects were divided into subjects with or without IR, no difference in ghrelin and ADMA was observed in these two subgroups. After intervention, the obese with IR showed increased ghrelin and decreased ADMA, while the obese without IR only showed improvement in ghrelin. The multiple linear regression analysis revealed that the changes of systolic blood pressure were the only predictor for the changes of ghrelin in the obese with IR. Our study demonstrated the increase of ADMA and the decrease of ghrelin in obese adolescents. Lifestyle intervention improved insulin resistance, decreased ADMA, and increased ghrelin in obese subjects with IR although no significant weight loss was observed.

The study of soluble intercellular adhesion molecule-1 and ghrelin in adolescents with family history of type 2 diabetes

The purpose of this study was to observe both the changes of soluble intercellular adhesion molecule-1 (sICAM-1) and ghrelin in adolescents with family history of type 2 diabetes (FHD) and the relationship between sICAM-1 and ghrelin. This case-control study included 63 adolescents (boys/girls 29/34, age 14.1 ± 0.7 years) without FHD (FHD-) and 67 adolescents (boys/girls 33/34, age 14.0 ± 0.8 years) with FHD (FHD+). Anthropometric measurements, including height, weight, waist circumference (WC), and blood pressure, were obtained. Blood samples were collected, and fasting plasma glucose (FPG), serum lipids, true insulin, sICAM-1, and ghrelin were assayed. The results showed that the age and gender were similar in two groups (P > 0.05). Body mass index (BMI), WC, FPG, fasting insulin, HOMA-IR, and sICAM-1 were all significantly higher in the FHD+ group than in the FHD- group (P < 0.05). Ghrelin was significantly lower in the FHD+ group than in the FHD- group (P < 0.05). sICAM-1 was positively correlated with WC (r = 0.178, P = 0.043), fasting insulin (r = 0.195, P = 0.026), HOMA-IR (r = 0.197, P = 0.024), and ghrelin (r = 0.290, P = 0.001). After multivariate analysis, the ghrelin (β = 0.788, 95 % CI: 0.416-1.159, P = 0.000) and HOMA-IR (β = 0.106, 95 % CI: 0.045-0.167, P = 0.001) maintained an independent association with sICAM-1. These findings led to the conclusion that endothelial dysfunction and decline of ghrelin were found in adolescents with family history of diabetes. The decline of ghrelin maybe a protection mechanism for endothelial function in adolescents with family history of diabetes and should be examined in future studies.

Insulin resistance and acne: a new risk factor for men?

The purpose of this study is to investigate the relationship between acne and insulin resistance as well as other metabolic impairment in young males. Acne is a skin disease that can be influenced by endocrine abnormalities. In females, it is associated with polycystic ovary syndrome, with peripheral insulin resistance and hyperinsulinemia, whereas few data are available in males. For investigating this, 22 young males with acne have been compared to 22 controls of comparable age and gender. Acne was scored using the global acne grading system score. Clinical as well as biochemical parameters of glucose and lipid metabolism, circulating levels of androgens, and IGF-1 were evaluated. Oral glucose tolerance test was performed and homeostasis model assessment of insulin resistance was calculated. The results thus obtained are as follows, patients had higher BMI (p = 0.003), WC (p = 0.002), WHR (p = 0.02), SBP (p = 0.0001), DBP (p = 0.001), basal (p = 0.01) and 120 min. oGTT serum insulin concentrations (p = 0.002), basal glucose concentrations (p = 0.03), HOMA-IR (p = 0.016), and lower HDL-cholesterol than controls (p = 0.001). Among the subgroup of subjects with BMI <24.9, HDL-cholesterol (p = 0.05) and 120 min. oGTT serum insulin concentrations (p = 0.009) resulted to be independent predictors of acne at multivariate analysis. In conclusion, these findings highlight a metabolic imbalance in young males affected with acne. Insulin resistance seems to play the main role for the development of acne in these subjects. Insulin resistance could represent an effective target for therapy in male acne.

Determining cut-off values for neck circumference as a measure of the metabolic syndrome amongst a South African cohort: the SABPA study

The aim was to determine receiver operating characteristic (ROC) neck circumference (NC) cut offs best associated with the metabolic syndrome (MetS) in a South African cohort. We included 409 urban Africans and Caucasians and stratified them into gender and age groups (25-45 years; 45-65 years). Measurements included anthropometric, fasting overnight urine and biological markers for the MetS (systolic and diastolic blood pressure, glucose, triglycerides, and high density lipoprotein). ROC analysis determined pathological (NC) cut-points of 39 and 35 cm for young and older African men; 32 and 35 cm for young and old African women; 40 and 41 cm for Caucasian men; 34 and 33 cm for Caucasian women. Pathological NC cut-points significantly predicted MetS in all ethnic-gender-age groups except in African women (ORs 2.3-5.4; 95% CI 1.36-16.5). Multiple regression analyses revealed that MetS prevalence and ROC cut-points were not associated with renal impairment in any groups. ROC NC cut-points demonstrated that NC may be used as an additional anthropometric marker to predict the MetS in a South African cohort but not in African women.

Insulin resistance in type 2 diabetic youth

PURPOSE OF REVIEW

This review focuses on recent literature on insulin resistance in youth with type 2 diabetes mellitus (T2DM). Insulin resistance is associated with a variety of cardiometabolic problems leading to increased morbidity and mortality across the lifespan.

RECENT FINDINGS

Functional pancreatic β-cell changes play a role in the transition from obesity to impaired glucose tolerance (IGT). Insulin resistance drives islet cell upregulation, manifested by elevated glucagon and c-peptide levels, early in the transition to IGT. Surrogate measurements of insulin resistance and insulin secretion exist but their accuracy compared to clamp data is imperfect. Recent large longitudinal studies provide detailed information on the progression from normoglycemia to T2DM and on the phenotype of T2DM youth. Defining prediabetes and T2DM remains a challenge in youth. Lifestyle interventions do not appear as effective in children as in adults. Metformin remains the only oral hypoglycemic agent approved for T2DM in youth.

SUMMARY

New insights exist regarding the conversion from insulin resistance to T2DM, measurement of insulin resistance and phenotypes of insulin resistance youth, but more information is needed. Surrogate measurements of insulin resistance, additional treatment options for insulin resistance and individualization of treatment options for T2DM adolescents in particular require further investigation.

Free fatty acid palmitate impairs the vitality and function of cultured human bladder smooth muscle cells

Background

Incidence of urinary tract infections is elevated in patients with diabetes mellitus. Those patients show increased levels of the saturated free fatty acid palmitate. As recently shown metabolic alterations induced by palmitate include production and secretion of the pro-inflammatory cytokine interleukine-6 (IL-6) in cultured human bladder smooth muscle cells (hBSMC). Here we studied the influence of palmitate on vital cell properties, for example, regulation of cell proliferation, mitochondrial enzyme activity and antioxidant capacity in hBSMC, and analyzed the involvement of major cytokine signaling pathways.

Methodology/Principal Findings

HBSMC cultures were set up from bladder tissue of patients undergoing cystectomy and stimulated with palmitate. We analyzed cell proliferation, mitochondrial enzyme activity, and antioxidant capacity by ELISA and confocal immunofluorescence. In signal transduction inhibition experiments we evaluated the involvement of NF-κB, JAK/STAT, MEK1, PI3K, and JNK in major cytokine signaling pathway regulation. We found: (i) palmitate decreased cell proliferation, increased mitochondrial enzyme activity and antioxidant capacity; (ii) direct inhibition of cytokine receptor by AG490 even more strongly suppressed cell proliferation in palmitate-stimulated cells, while counteracting palmitate-induced increase of antioxidant capacity; (iii) in contrast knockdown of the STAT3 inhibitor SOCS3 increased cell proliferation and antioxidant capacity; (iv) further downstream JAK/STAT3 signaling cascade the inhibition of PI3K or JNK enhanced palmitate induced suppression of cell proliferation; (v) increase of mitochondrial enzyme activity by palmitate was enhanced by inhibition of PI3K but counteracted by inhibition of MEK1.

Conclusions/Significance

Saturated free fatty acids (e.g., palmitate) cause massive alterations in vital cell functions of cultured hBSMC involving distinct major cytokine signaling pathways. Thereby, certain cytokines might counteract the palmitate-induced downregulation of cell proliferation and vitality. This could be an important link to clinical findings of increased risk of metabolic related bladder diseases such as overactive bladder (OAB) and bladder pain syndrome/interstitial cystitis (BPS/IC).