Indexes of insulin resistance and secretion in obese children and adolescents

OBJECTIVE - To assess the concurrent validity of fasting indexes of insulin sensitivity and secretion in - obese prepubertal (Tanner stage 1) children and pubertal (Tanner stages 2-5) glucose tolerance test (FSIVGTT) as a criterion measure. RESEARCH DESIGN AND METHODS - Eighteen obese children and adolescents (11 girls and 7 boys, mean age 12.2 +/- 2.4 years, mean BMI 35.4 +/- 6.2 kg/m(2), mean BMI-SDS 3.5 +/- 0.5, 7 prepubertal and I I pubertal) participated in the study. All participants underwent an insulin-modified FSIVGTT on two occasions, and 15 repeated this test a third time (mean 12.9 and 12.0 weeks apart). S-i measured by the FSIVGTT was compared with homeostasis model assessment (HOMA) of insulin resistance (HOMA-IR), quantitative insulin-sensitivity check index (QUICKI), fasting glucose-to-insulin ratio (FGIR), and fasting insulin (estimates of insulin sensitivity derived from fasting samples). The acute insulin response (AIR) measured by the FSIVGTT was compared with HOMA of percent beta-cell function (HOMA-beta%), FGIR, and fasting insulin (estimates of insulin secretion derived from fasting samples). RESULTS - There was a significant negative correlation between HOMA-IR and S-i (r = -0.89, r = -0.90, and r = -0.81, P < 0.01) and a significant positive correlation between QUICKI and S-i (r = 0.89, r = 0.90, and r = 0.81, P < 0.01) at each time point. There was a significant positive correlation between FGIR and S-i (r = 0.91, r = 0.91, and r = 0.82, P < 0.01) and a significant negative correlation between fasting insulin and S-i (r = -90, r = -0.90, and r = -0.88, P < 0.01). HOMA-beta% was not as strongly correlated with AIR (r = 0.60, r = 0.54, and r = 0.61, P < 0.05). CONCLUSIONS - HOMA-IR, QUICKI, FGIR, and fasting insulin correlate strongly with S-i assessed by the FSIVGTT in obese children and adolescents. Correlations between HOMA-β% FGIR and fasting insulin, and AIR were not as strong. Indexes derived from fasting samples are a valid tool for assessing insulin sensitivity in prepubertal and pubertal obese children.

Insulin resistance is a determinant of myocardial dysfunction in apparently healthy obese subjects

Background. Obese pts have subclinical myocardial dysfunction that may account for their risk of heart failure. We sought the contribution of insulin resistance (IR) to myocardial dysfunction in obesity. Methods. Asymptomatic obese subjects without known cardiac disease underwent clinical evaluation, homeostasis model assessment (HOMA score) as a measure of insulin sensitivity and echocardiographic assessment. After exclusion of DM, overt myocardial dysfunction or ischemia, subclinical myocardial function was assessed by myocardial systolic (Sm) and diastolic velocity (Em) in 79 pts. Association was sought between myocardial function with clinical and biochemical characteristics. Results HOMA score categorized 36 pts as non-IR (HOMA

Oxidative and inflammatory status in Type 2 diabetes patients with periodontitis

Aim: To determine the impact of periodontitis on oxidative/inflammatory status and diabetes control in Type 2 diabetes. Materials and Methods: A comparative study of 20 Type 2 diabetes patients with periodontitis [body mass index (BMI) 31+5], 20-age/gender-matched, non-periodontitis Type 2 diabetes controls (BMI 29+6) and 20 non-diabetes periodontitis controls (BMI 25+4) had periodontal examinations and fasting blood samples collected. Oxidative stress was determined by plasma small molecule antioxidant capacity (pSMAC) and protein carbonyl levels; inflammatory status by total/differential leucocytes, fibrinogen and high sensitivity C-reactive protein (hsCRP); diabetes status by fasting glucose, HbA1c, lipid profile, insulin resistance and secretion. Statistical analysis was performed using SPSS. Results: pSMAC was lower (p=0.03) and protein carbonyls higher (p=0.007) in Type 2 diabetes patients with periodontitis compared with those without periodontitis. Periodontitis was associated with significantly higher HbA1c (p=0.002) and fasting glucose levels (p=0.04) and with lower ß-cell function (HOMA-ß; p=0.01) in diabetes patients. Periodontitis had little effect on inflammatory markers or lipid profiles, but Type 2 diabetes patients with periodontitis had higher levels of hsCRP than those without diabetes (p=0.004) and the lowest levels of HDL-cholesterol of all groups. Conclusion: Periodontitis is associated with increased oxidative stress and compromised glycaemic control in Type 2 diabetes patients.

The association of depression and perceived stress with beta cell function between African and Haitian Americans with and without type 2 diabetes

Background: Diabetes and diabetes-related complications are major causes of morbidity and mortality in the United States. Depressive symptoms and perceived stress have been identified as possible risk factors for beta cell dysfunction and diabetes. The purpose of this study was to assess associations between depression symptoms and perceived stress with beta cell function between African and Haitian Americans with and without type 2 diabetes. Participants and Methods: Informed consent and data were available for 462 participants (231 African Americans and 231 Haitian Americans) for this cross-sectional study. A demographic questionnaire developed by the Primary Investigator was used to collect information regarding age, gender, smoking, and ethnicity. Diabetes status was determined by self-report and confirmed by fasting blood glucose. Anthropometrics (weight, and height and waist circumference) and vital signs (blood pressure) were taken. Blood samples were drawn after 8 10 hours over-night fasting to measure lipid panel, fasting plasma glucose and serum insulin concentrations. The homeostatic model assessment, version 2 (HOMA2) computer model was used to calculate beta cell function. Depression was assessed using the Beck Depression Inventory-II (BDI-II) and stress levels were assessed using the Perceived Stress Scale (PSS). Results: Moderate to severe depressive symptoms were more likely for persons with diabetes (p = 0.030). There were no differences in perceived stress between ethnicity and diabetes status (p = 0.283). General linear models for participants with and without type 2 diabetes using beta cell function as the dependent variable showed no association with depressive symptoms and perceived stress; however, Haitian Americans had significantly lower beta cell function than African Americans both with and without diabetes and adjusting for age, gender, waist circumference and smoking. Further research is needed to compare these risk factors in other race/ethnic groups.

Use of Homeostatic Model Assessment Indexes for the Identification of Metabolic Syndrome and Insulin Resistance among Cuban-Americans: A Cross Sectional Study

Aim: to determine cut off points for The Homeostatic Model Assessment Index 1 and 2 (HOMA-1 and HOMA-2) for identifying insulin resistance and metabolic syndrome among a Cuban-American population. Study Design: Cross sectional. Place and Duration of Study: Florida International University, Robert Stempel School of Public Health and Social Work, Department of Dietetics and Nutrition, Miami, FL from July 2010 to December 2011. Methodology: Subjects without diabetes residing in South Florida were enrolled (N=146, aged 37 to 83 years). The HOMA1-IR and HOMA2-IR 90th percentile in the healthy group (n=75) was used as the cut-off point for insulin resistance. A ROC curve was constructed to determine the cut-off point for metabolic syndrome. Results: HOMA1-IR was associated with BMI, central obesity, and triglycerides (P3.95 and >2.20 and for metabolic syndrome were >2.98 (63.4% sensitivity and 73.3% specificity) and >1.55 (60.6% sensitivity and 66.7% specificity), respectively. Conclusion: HOMA cut-off points may be used as a screening tool to identify insulin resistance and metabolic syndrome among Cuban-Americans living in South Florida.

A influência da perda de peso no perfil inflamatório de mulheres com síndrome dos ovários policísticos

The polycystic ovary syndrome (PCOS) is considered the most common endocrine disorder in reproductive age women, with a prevalence ranging from 15 to 20%. In addition to hormonal and reproductive changes, it is common in PCOS the presence of risk factors for developing cardiovascular disease (CVD) and diabetes mellitus, insulin resistance (IR), visceral obesity, chronic low-grade inflammation and dyslipidemia. Due to the high frequency of obesity associated with PCOS, weight loss is considered as the first-line treatment for the syndrome by improving metabolic and normalizes serum androgens, restoring reproductive function of these patients. Objectives: To evaluate the inflammatory markers and IR in women with PCOS and healthy ovulatory with different nutritional status and how these parameters are displayed after weight loss through caloric restriction in with Down syndrome. Methods: Tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6) and C-reactive protein (CRP) were assessed in serum samples from 40 women of childbearing age. The volunteers were divided into four groups: Group I (not eutrophic with PCOS, n = 12); Group II (not eutrophic without PCOS, n = 10), Group III (eutrophic with PCOS, n = 08) and Group IV (eutrophic without PCOS, n = 10). The categorization of groups was performed by body mass index (BMI), according to the World Health Organization (WHO) does not eutrophic, overweight and obesity (BMI> 25 kg / m²) and normal weight (BMI <24.9 kg / m²). IR was determined by HOMA-IR index. In the second phase of the study a controlled dietary intervention was performed and inflammatory parameters were evaluated in 21 overweight and obese women with PCOS, before and after weight loss. All patients received a low-calorie diet with reduction of 500 kcal / day of regular consumption with standard concentrations of macronutrients. Results: Phase 1: PCOS patients showed increased levels of CRP (p <0.01) and HOMAIR (p <0.01). When divided by BMI, both not eutrophic group with PCOS (I) as eutrophic with PCOS (III) showed increased levels of CRP (I = 2.35 ± 0,55mg / L and 2.63 ± III = 0,65mg / L; p <0.01) and HOMA-IR (I = 2.16 ± 2.54 and III = 1.07 ± 0.55; p <0.01). There were no differences in TNF-α and IL-6 between groups. Step 2: After the weight loss of 5% of the initial weight was reduced in all of the components of serum assessed inflammatory profile, PCR (154.75 ± 19:33) vs (78.06 ± 8.9) TNF α (10.89 ± 5.09) vs (6:39 ± 1:41) and IL6 (154.75 ± 19:33) vs (78.06 ± 08.09) (p <0:00) in association with improvement some hormonal parameters evaluated. Conclusion: PCOS contributed to the development of chronic inflammation and changes in glucose metabolism by increasing CRP, insulin and HOMA-IR, independent of nutritional status. The weight loss, caloric restriction has improved the inflammatory condition and hormonal status of the evaluated patients.