Effects of Chronic Calorie Restriction or Dietary Resveratrol Supplementation on Insulin Sensitivity Markers in a Primate, Microcebus murinus

The prevalence of diabetes and hyperinsulinemia increases with age, inducing metabolic failure and limiting lifespan. Calorie restriction (CR) without malnutrition delays the aging process, but its long-term application to humans seems difficult. Resveratrol (RSV), a dietary polyphenol, appears to be a promising CR mimetic that can be easily administered in humans. In this work, we hypothesized that both CR and RSV impact insulin sensitivity in a non-human primate compared to standard-fed control (CTL) animals. Four- to five-year-old male grey mouse lemurs (Microcebus murinus) were assigned to three dietary groups: a CTL group, a CR group receiving 30% fewer calories than the CTL and a RSV group receiving the CTL diet supplemented with RSV (200 mg·day−1·kg−1). Insulin sensitivity and glycemia were assessed using an oral glucose tolerance test (OGTT) and the homeostasis model assessment of insulin resistance (HOMA-IR index) evaluation after 21 or 33 months of chronic treatment. Resting metabolic rate was also measured to assess the potential relationships between this energy expenditure parameter and insulin sensitivity markers. No differences were found after a 21-month period of treatment, except for lower glucose levels 30 min after glucose loading in CR animals. After 33 months, CR and RSV decreased glycemia after the oral glucose loading without decreasing fasting blood insulin. A general effect of treatment was observed on the HOMA-IR index, with an 81% reduction in CR animals and 53% in RSV animals after 33 months of treatment compared to CTL. Chronic CR and dietary supplementation with RSV affected insulin sensitivity by improving the glucose tolerance of animals without disturbing their baseline insulin secretion. These results suggest that both CR and RSV have beneficial effects on metabolic alterations, although these effects are different in amplitude between the two anti-aging treatments and potentially rely on different metabolic changes

Red wine polyphenols prevent metabolic and cardiovascular alterations associated with obesity in Zucker fatty rats (Fa/Fa)

Peer reviewedPublisher PD

Abnormalities in autonomic function in obese boys at-risk for insulin resistance and obstructive sleep apnea.

Study objectivesCurrent evidence in adults suggests that, independent of obesity, obstructive sleep apnea (OSA) can lead to autonomic dysfunction and impaired glucose metabolism, but these relationships are less clear in children. The purpose of this study was to investigate the associations among OSA, glucose metabolism, and daytime autonomic function in obese pediatric subjects.MethodsTwenty-three obese boys participated in: overnight polysomnography; a frequently sampled intravenous glucose tolerance test; and recordings of spontaneous cardiorespiratory data in both the supine (baseline) and standing (sympathetic stimulus) postures.ResultsBaseline systolic blood pressure and reactivity of low-frequency heart rate variability to postural stress correlated with insulin resistance, increased fasting glucose, and reduced beta-cell function, but not OSA severity. Baroreflex sensitivity reactivity was reduced with sleep fragmentation, but only for subjects with low insulin sensitivity and/or low first-phase insulin response to glucose.ConclusionsThese findings suggest that vascular sympathetic activity impairment is more strongly affected by metabolic dysfunction than by OSA severity, while blunted vagal autonomic function associated with sleep fragmentation in OSA is enhanced when metabolic dysfunction is also present

Autism Symptoms and Internalizing Psychopathology in Girls and Boys with Autism Spectrum Disorders

Findings regarding phenotypic differences between boys and girls with ASD are mixed. We compared autism and internalizing symptoms in a sample of 8-18 year-old girls (n = 20) and boys (n = 20) with ASD and typically developing (TYP) girls (n = 19) and boys (n = 17). Girls with ASD were more impaired than TYP girls but did not differ from boys with ASD in autism symptoms. In adolescence, girls with ASD had higher internalizing symptoms than boys with ASD and TYP girls, and higher symptoms of depression than TYP girls. Girls ages 8-18 with ASD resemble boys with ASD and not TYP girls, and appear to be at increased risk for affective symptoms in the teen years

The APOA5 Trp19 allele is associated with metabolic syndrome via its association with plasma triglycerides

<p>Abstract</p> <p>Background</p> <p>The goal of the present study was to assess the effect of genetic variability at the APOA5/A4/C3/A1 cluster locus on the risk of metabolic syndrome.</p> <p>Methods</p> <p>The <it>APOA5 </it>Ser19Trp, <it>APOA5 </it>-12,238T>C, <it>APOA4 </it>Thr347Ser, <it>APOC3 </it>-482C>T and <it>APOC3 </it>3238C>G (<it>Sst</it>I) polymorphisms were analyzed in a representative population sample of 3138 men and women from France, including 932 individuals with metabolic syndrome and 2206 without metabolic syndrome, as defined by the NCEP criteria.</p> <p>Results</p> <p>Compared with homozygotes for the common allele, the odds ratio (OR) [95% CI] for metabolic syndrome was 1.30 [1.03–1.66] (<it>p </it>= 0.03) for <it>APOA5 </it>Trp19 carriers, 0.81 [0.69–0.95] (<it>p </it>= 0.01) for <it>APOA5 </it>-12,238C carriers and 0.84 [0.70–0.99] (<it>p </it>= 0.04) for <it>APOA4 </it>Ser347 carriers. Adjustment for plasma triglycerides, (but not for waist girth, HDL, blood pressure or glycemia – the other components of metabolic syndrome) abolished these associations and suggests that triglyceride levels explain the association with metabolic syndrome. There was no association between the <it>APOC3 </it>-482C>T or <it>APOC3 </it>3238C>G polymorphisms and metabolic syndrome. The decreased risk of metabolic syndrome observed in <it>APOA5 </it>-12,238C and <it>APOA4 </it>Ser347 carriers merely reflected the fact that the <it>APOA5 </it>Trp19 allele was in negative linkage disequilibrium with the common alleles of <it>APOA5 </it>-12,238T>C and <it>APOA4 </it>Thr347Ser polymorphisms.</p> <p>Conclusion</p> <p>The <it>APOA5 </it>Trp19 allele increased susceptibility to metabolic syndrome via its impact on plasma triglyceride levels.</p

Prevalence of metabolic syndrome in Murcia Region, a southern European Mediterranean area with low cardiovascular risk and high obesity

<p>Abstract</p> <p>Background</p> <p>Metabolic syndrome (MS) is associated with subsequent appearance of diabetes and cardiovascular disease. As compared to other Spanish regions, Murcia (southern Spain) registers increased obesity as well as cardiovascular morbidity and mortality. The aim of this study was to assess the prevalence of MS and its components, awareness of obesity as a health risk and associated lifestyles.</p> <p>Methods</p> <p>A population-based, cross-sectional study was conducted in 2003, covering a sample of 1555 individuals 20 years and over. MS was defined according to the Revised National Cholesterol Education Program Adult Treatment Panel III (R-ATPIII), International Diabetes Federation (IDF) and Joint Interim Statement (JIS) criteria. Both low (94/80) and high (102/88) waist circumference (WC) thresholds were considered.</p> <p>Results</p> <p>Prevalence of MS was 27.2% (95%CI: 25.2-29.2), 32.2% (95%CI: 30.1-34.3) and 33.2% (95%CI: 31.2-35.3) according to the R-ATPIII, IDF and JIS94/80 respectively. It increased with age until reaching 52.6% (R-ATPIII) or 60.3% (JIS94/80) among persons aged 70 years and over, and was higher in persons with little or no formal education (51.7% R-ATPIII, 57.3% JIS94/80). The most common risk factors were hypertension (46.6%) and central obesity (40.7% and 66.1% according to high and low WC cut-off points respectively). Although most persons were aware that obesity increased health risks, regular exercise was very unusual (13.0% centrally obese, 27.2% non-centrally obese). Adherence to dietary recommendations was similar among centrally obese and non-centrally obese subjects.</p> <p>Conclusions</p> <p>Prevalence of MS is high in our population, is comparable to that found in northern Europe and varies with the definition used. Adherence to preventive recommendations and to adequate weight promotion is very low. In the absence of a specific treatment for MS, integrated intervention based on a sustained increase in physical activity and changes in diet should be reinforced.</p

Fatty acid-induced mitochondrial uncoupling in adipocytes as a key protective factor against insulin resistance and beta cell dysfunction: a new concept in the pathogenesis of obesity-associated type 2 diabetes mellitus

Type 2 diabetes is associated with excessive food intake and a sedentary lifestyle. Local inflammation of white adipose tissue induces cytokine-mediated insulin resistance of adipocytes. This results in enhanced lipolysis within these cells. The fatty acids that are released into the cytosol can be removed by mitochondrial β-oxidation. The flux through this pathway is normally limited by the rate of ADP supply, which in turn is determined by the metabolic activity of the adipocyte. It is expected that the latter does not adapt to an increased rate of lipolysis. We propose that elevated fatty acid concentrations in the cytosol of adipocytes induce mitochondrial uncoupling and thereby allow mitochondria to remove much larger amounts of fatty acids. By this, release of fatty acids out of adipocytes into the circulation is prevented. When the rate of fatty acid release into the cytosol exceeds the β-oxidation capacity, cytosolic fatty acid concentrations increase and induce mitochondrial toxicity. This results in a decrease in β-oxidation capacity and the entry of fatty acids into the circulation. Unless these released fatty acids are removed by mitochondrial oxidation in active muscles, these fatty acids result in ectopic triacylglycerol deposits, induction of insulin resistance, beta cell damage and diabetes. Thiazolidinediones improve mitochondrial function within adipocytes and may in this way alleviate the burden imposed by the excessive fat accumulation associated with the metabolic syndrome. Thus, the number and activity of mitochondria within adipocytes contribute to the threshold at which fatty acids are released into the circulation, leading to insulin resistance and type 2 diabetes