Analysis of sequence variability in the CART gene in relation to obesity in a Caucasian population

BACKGROUND: Cocaine and amphetamine regulated transcript (CART) is an anorectic neuropeptide located principally in hypothalamus. CART has been shown to be involved in control of feeding behavior, but a direct relationship with obesity has not been established. The aim of this study was to evaluate the effect of polymorphisms within the CART gene with regards to a possible association with obesity in a Caucasian population. RESULTS: Screening of the entire gene as well as a 3.7 kb region of 5' upstream sequence revealed 31 SNPs and 3 rare variants ; 14 of which were subsequently genotyped in 292 French morbidly obese subjects and 368 controls. Haplotype analysis suggested an association with obesity which was found to be mainly due to SNP-3608T>C (rs7379701) (p = 0.009). Genotyping additional cases and controls also of European Caucasian origin supported further this possible association between the CART SNP -3608T>C T allele and obesity (global p-value = 0.0005). Functional studies also suggested that the SNP -3608T>C could modulate nuclear protein binding. CONCLUSION: CART SNP -3608T>C may possibly contribute to the genetic risk for obesity in the Caucasian population. However confirmation of the importance of the role of the CART gene in energy homeostasis and obesity will require investigation and replication in further populations

Randomized, double-blind, placebo-controlled crossover trial of once daily empagliflozin 25 mg for the treatment of postprandial hypoglycaemia after Roux-en-Y gastric bypass.

Aims To investigate the effect of empagliflozin on glucose dynamics in individuals suffering from postbariatric hypoglycaemia (PBH) after Roux-en-Y gastric bypass (RYGB). Methods Twenty-two adults with PBH after RYGB were randomized to empagliflozin 25 mg or placebo once daily over 20 days in a randomized, double-blind, placebo-controlled, crossover trial. The primary efficacy outcome was the amplitude of plasma glucose excursion (peak to nadir) during a mixed meal tolerance test (MMTT). Outcomes of the outpatient period were assessed using continuous glucose monitoring (CGM) and an event-tracking app. Results The amplitude of glucose excursion during the MMTT was 8.1±2.4 mmol/L with empagliflozin vs 8.1±2.6 mmol/L with placebo (mean±SD, p=0.807). CGM-based mean amplitude of glucose excursion (MAGE) during the 20 day-period was lower with empagliflozin than placebo (4.8±1.3 vs 5.2±1.6. p=0.028). Empagliflozin reduced the time spent with CGM values >10.0 mmol/L (3.8±3.5 % vs. 4.7±3.8 %, p =0.009), but not the time spent with CGM values <3.0 mmol/L (1.7±1.6 % vs. 1.5±1.5 %, p=0.457). No significant difference was observed in the quantity and quality of recorded symptoms. Eleven adverse events occurred with empagliflozin (three drug-related) and six with placebo. Conclusions Empagliflozin 25 mg reduces glucose excursions but not hypoglycaemia in individuals with PBH

Randomized, Double-Blind, Placebo-Controlled Crossover Trial of Once Daily Empagliflozin 25 mg for the Treatment of Postprandial Hypoglycemia After Roux-en-Y Gastric Bypass

Aims: To investigate the effect of empagliflozin on glucose dynamics in individuals suffering from postbariatric hypoglycemia (PBH) after Roux-en-Y gastric bypass (RYGB). Methods: Twenty-two adults with PBH after RYGB were randomized to empagliflozin 25 mg or placebo once daily over 20 days in a randomized, double-blind, placebo-controlled, crossover trial. The primary efficacy outcome was the amplitude of plasma glucose excursion (peak to nadir) during a mixed-meal tolerance test (MMTT). Outcomes of the outpatient period were assessed using continuous glucose monitoring (CGM) and an event-tracking app. Results: The amplitude of glucose excursion during the MMTT was 8.1 ± 2.4 mmol/L with empagliflozin versus 8.1 ± 2.6 mmol/L with placebo (mean ± standard deviation, P = 0.807). CGM-based mean amplitude of glucose excursion during the 20-day period was lower with empagliflozin than placebo (4.8 ± 1.3 vs. 5.2 ± 1.6. P = 0.028). Empagliflozin reduced the time spent with CGM values >10.0 mmol/L (3.8 ± 3.5% vs. 4.7 ± 3.8%, P = 0.009), but not the time spent with CGM values <3.0 mmol/L (1.7 ± 1.6% vs. 1.5 ± 1.5%, P = 0.457). No significant difference was observed in the quantity and quality of recorded symptoms. Eleven adverse events occurred with empagliflozin (three drug-related) and six with placebo. Conclusions: Empagliflozin 25 mg reduces glucose excursions but not hypoglycemia in individuals with PBH

The genetic susceptibility to type 2 diabetes may be modulated by obesity status: implications for association studies

<p>Abstract</p> <p>Background</p> <p>Considering that a portion of the heterogeneity amongst previous replication studies may be due to a variable proportion of obese subjects in case-control designs, we assessed the association of genetic variants with type 2 diabetes (T2D) in large groups of obese and non-obese subjects.</p> <p>Methods</p> <p>We genotyped <it>RETN</it>, <it>KCNJ11</it>, <it>HNF4A</it>, <it>HNF1A</it>, <it>GCK</it>, <it>SLC30A8</it>, <it>ENPP1</it>, <it>ADIPOQ</it>, <it>PPARG</it>, and <it>TCF7L2 </it>polymorphisms in 1,283 normoglycemic (NG) and 1,581 T2D obese individuals as well as in 3,189 NG and 1,244 T2D non-obese subjects of European descent, allowing us to examine T2D risk over a wide range of BMI.</p> <p>Results</p> <p>Amongst non-obese individuals, we observed significant T2D associations with <it>HNF1A </it>I27L [odds ratio (OR) = 1.14, <it>P </it>= 0.04], <it>GCK </it>-30G>A (OR = 1.23, <it>P </it>= 0.01), <it>SLC30A8 </it>R325W (OR = 0.87, <it>P </it>= 0.04), and <it>TCF7L2 </it>rs7903146 (OR = 1.89, <it>P </it>= 4.5 × 10^-23), and non-significant associations with <it>PPARG </it>Pro12Ala (OR = 0.85, <it>P </it>= 0.14), <it>ADIPOQ </it>-11,377C>G (OR = 1.00, <it>P </it>= 0.97) and <it>ENPP1 </it>K121Q (OR = 0.99, <it>P </it>= 0.94). In obese subjects, associations with T2D were detected with <it>PPARG </it>Pro12Ala (OR = 0.73, <it>P </it>= 0.004), <it>ADIPOQ </it>-11,377C>G (OR = 1.26, <it>P </it>= 0.02), <it>ENPP1 </it>K121Q (OR = 1.30, <it>P </it>= 0.003) and <it>TCF7L2 </it>rs7903146 (OR = 1.30, <it>P </it>= 1.1 × 10^-4), and non-significant associations with <it>HNF1A </it>I27L (OR = 0.96, <it>P </it>= 0.53), <it>GCK </it>-30G>A (OR = 1.15, <it>P </it>= 0.12) and <it>SLC30A8 </it>R325W (OR = 0.95, <it>P </it>= 0.44). However, a genotypic heterogeneity was only found for <it>TCF7L2 </it>rs7903146 (<it>P </it>= 3.2 × 10^-5) and <it>ENPP1 </it>K121Q (<it>P </it>= 0.02). No association with T2D was found for <it>KCNJ11</it>, <it>RETN</it>, and <it>HNF4A </it>polymorphisms in non-obese or in obese individuals.</p> <p>Conclusion</p> <p>Genetic variants modulating insulin action may have an increased effect on T2D susceptibility in the presence of obesity, whereas genetic variants acting on insulin secretion may have a greater impact on T2D susceptibility in non-obese individuals.</p

Binge eating as a major phenotype of melanocortin 4 receptor gene mutations

Background Obesity, a multifactorial disease caused by the interaction of genetic factors with the environment, is largely polygenic. A few mutations in these genes, such as in the leptin receptor (LEPR) gene and melanocortin 4 receptor (MC4R) gene, have been identified as causes of monogenic obesity. Methods We sequenced the complete MC4R coding region, the region of the proopiomelanocortin gene (POMC) encoding the melanocyte-stimulating hormone, and the leptin-binding domain of LEPR in 469 severely obese white subjects (370 women and 99 men; mean [±SE] age, 41.0±0.5 years; body-mass index [the weight in kilograms divided by the square of the height in meters], 44.1±2.0). Fifteen women and 10 men without a history of dieting or a family history of obesity served as normal-weight controls (age, 47.7±2.0 years; body-mass index, 21.6±0.4). Detailed phenotypic data, including information on body fat, resting energy expenditure, diet-induced thermogenesis, serum concentrations of leptin, and eating behavior, were collected. Results Twenty-four obese subjects (5.1 percent) and one control subject (4 percent) had MC4R mutations, including five novel variants. Twenty of the 24 obese subjects with an MC4R mutation were matched for age, sex, and body-mass index with 120 of the 445 obese subjects without an MC4R mutation. All mutation carriers reported binge eating, as compared with 14.2 percent of obese subjects without mutations (P<0.001) and 0 percent of the normal-weight subjects without mutations. The prevalence of binge eating was similar among carriers of mutations in the leptin-binding domain of LEPR and noncarriers. No mutations were found in the region of POMC encoding melanocyte-stimulating hormone. Conclusions: Binge eating is a major phenotypic characteristic of subjects with a mutation in MC4R, a candidate gene for the control of eating behavior

Effects of TCF7L2 polymorphisms on obesity in European populations.

1930-7381 (Print) Journal Article Research Support, Non-U.S. Gov'tInternational audienceThe transcription factor 7-like 2 (TCF7L2) rs7903146 T allele was previously associated with type 2 diabetes (T2D) and decreased BMI whereas haplotypes carrying the rs7903146 C and rs10885406 A alleles (HapA) were associated with increased BMI. The functional relevance of TCF7L2 polymorphisms and their effects on T2D and obesity remained to be further investigated.In white European populations, we found that the rs7903146 T allele was more associated with T2D in 3,547 non-obese individuals (odds ratio (OR) = 1.88 (1.69-2.10)) than in 1,110 class III obese subjects (OR = 1.24 (1.03-1.50)). No direct effect of the rs7903146 C allele and HapA was found on any form of obesity in 3,507 normal glucose tolerant (NGT) individuals, 1,106 pedigrees with familial obesity and 5,512 individuals from the French general population. However, in T2D subjects, the rs7903146 C allele was less prevalent in the 1,111 non-obese individuals (55.2%) compared to 659 class III obese subjects (67.5% OR = 1.69 (1.46-1.95)). Functional studies showed that the rs7903146 T allele is less prone to be bound by protein factors than the C allele in 3T3-L1, HepG2 and beta-TC3 cell lines and that TCF7L2 expression decreases in subcutaneous adipose tissue from NGT obese T/T carriers under calorie restriction.In conclusion, TCF7L2 is not a risk factor for obesity in European populations, but its effect on T2D risk is modulated by obesity. Furthermore, our data suggest that the rs7903146 T allele may be possibly functional and associated with a nominal decrease in TCF7L2 expression in adipose tissue of individuals under calorie restriction