| 1. |
- Metcalfe, N. B., et al.
(author)
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Solving the conundrum of intra-specific variation in metabolic rate: A multidisciplinary conceptual and methodological toolkit New technical developments are opening the door to an understanding of why metabolic rate varies among individual animals of a species
- 2023
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In: Bioessays. - 0265-9247. ; 45:6
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Journal article (peer-reviewed)abstract
- Researchers from diverse disciplines, including organismal and cellular physiology, sports science, human nutrition, evolution and ecology, have sought to understand the causes and consequences of the surprising variation in metabolic rate found among and within individual animals of the same species. Research in this area has been hampered by differences in approach, terminology and methodology, and the context in which measurements are made. Recent advances provide important opportunities to identify and address the key questions in the field. By bringing together researchers from different areas of biology and biomedicine, we describe and evaluate these developments and the insights they could yield, highlighting the need for more standardisation across disciplines. We conclude with a list of important questions that can now be addressed by developing a common conceptual and methodological toolkit for studies on metabolic variation in animals.
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| 2. |
- den Hoed, M, et al.
(author)
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SNP analyses of postprandial responses in (an)orexigenic hormones and feelings of hunger reveal long-term physiological adaptations to facilitate homeostasis.
- 2008
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In: International Journal of Obesity. - : Springer Science and Business Media LLC. - 0307-0565 .- 1476-5497. ; 32:12
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Journal article (peer-reviewed)abstract
- BACKGROUND: The postprandial responses in (an)orexigenic hormones and feelings of hunger are characterized by large inter-individual differences. Food intake regulation was shown earlier to be partly under genetic control.OBJECTIVE: This study aimed to determine whether the postprandial responses in (an)orexigenic hormones and parameters of food intake regulation are associated with single nucleotide polymorphisms (SNPs) in genes encoding for satiety hormones and their receptors.DESIGN: Peptide YY (PYY), glucagon-like peptide 1 and ghrelin levels, as well as feelings of hunger and satiety, were determined pre- and postprandially in 62 women and 41 men (age 31+/-14 years; body mass index 25.0+/-3.1 kg/m(2)). Dietary restraint, disinhibition and perceived hunger were determined using the three-factor eating questionnaire. SNPs were determined in the GHRL, GHSR, LEP, LEPR, PYY, NPY, NPY2R and CART genes.RESULTS: The postprandial response in plasma ghrelin levels was associated with SNPs in PYY (215G>C, P<0.01) and LEPR (326A>G and 688A>G, P<0.01), and in plasma PYY levels with SNPs in GHRL (-501A>C, P<0.05) and GHSR (477G>A, P<0.05). The postprandial response in feelings of hunger was characterized by an SNP-SNP interaction involving SNPs in LEPR and NPY2R (668A>G and 585T>C, P<0.05). Dietary restraint and disinhibition were associated with an SNP in GHSR (477G>A, P<0.05), and perceived hunger with SNPs in GHSR and NPY (477G>A and 204T>C, P<0.05).CONCLUSIONS: Part of the inter-individual variability in postprandial responses in (an)orexigenic hormones can be explained by genetic variation. These postprandial responses represent either long-term physiological adaptations to facilitate homeostasis or reinforce direct genetic effects.
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| 3. |
- den Hoed, Marcel, et al.
(author)
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Postprandial responses in hunger and satiety are associated with the rs9939609 single nucleotide polymorphism in FTO.
- 2009
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In: American Journal of Clinical Nutrition. - : Elsevier BV. - 0002-9165 .- 1938-3207. ; 90:5
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Journal article (peer-reviewed)abstract
- BACKGROUND: The common rs9939609 single nucleotide polymorphism (SNP) in the fat mass and obesity-associated (FTO) gene is associated with adiposity, possibly by affecting satiety responsiveness.OBJECTIVE: The objective was to determine whether postprandial responses in hunger and satiety are associated with rs9939609, taking interactions with other relevant candidate genes into account.DESIGN: Sixty-two women and 41 men [age: 31 +/- 14 y; body mass index (in kg/m(2)): 25.0 +/- 3.1] were genotyped for 5 SNPs in FTO, DNMT1, DNMT3B, LEP, and LEPR. Individuals received fixed meals provided in energy balance. Hunger and satiety were determined pre- and postprandially by using visual analog scales.RESULTS: A general association test showed a significant association between postprandial responses in hunger and satiety with rs9939609 (P = 0.036 and P = 0.050, respectively). Individuals with low postprandial responses in hunger and satiety were overrepresented among TA/AA carriers in rs9939609 (FTO) compared with TT carriers (dominant and additive model: P = 0.013 and P = 0.020, respectively). Moreover, multifactor dimensionality reduction showed significant epistatic interactions for the postprandial decrease in hunger involving rs9939609 (FTO), rs992472 (DNMT3B), and rs1137101 (LEPR). Individuals with a low postprandial decrease in hunger were overrepresented among TA/AA (dominant), CC/CA (recessive), and AG/GG (dominant) carriers in rs9939609 (FTO), rs992472 (DNMT3B), and rs1137101 (LEPR), respectively (n = 39), compared with TT, AA, and/or AA carriers in these SNPs, respectively (P = 0.00001). Each SNP had an additional effect.CONCLUSIONS: Our results confirm a role for FTO in responsiveness to hunger and satiety cues in adults in an experimental setting. The epistatic interaction suggests that DNA methylation, an epigenetic process, affects appetite.
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| 4. |
- van Vught, A. J. A. H., et al.
(author)
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The effects of dietary protein on the somatotropic axis : a comparison of soy, gelatin, alpha-lactalbumin and milk
- 2010
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In: European Journal of Clinical Nutrition. - : Springer Science and Business Media LLC. - 0954-3007 .- 1476-5640. ; 64:5, s. 441-446
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Journal article (peer-reviewed)abstract
- BACKGROUND/OBJECTIVES: Growth hormone (GH) is an important regulator of growth and body composition. It has been shown that GH release can be promoted by administration of various amino acids (AAs), such as arginine and lysine, that are present in soy protein. We previously showed that oral ingestion of soy protein stimulates the GH release, it is not known however to which extent other proteins stimulate the GH secretion.SUBJECTS/METHODS: Ingestion of soy protein (soy), gelatin protein (gelatin), alpha-lactalbumin protein (alpha-lactalbumin) and milk protein (milk) were compared on their GH-stimulating capacity. After oral ingestion of protein (0.6 g protein per kg bodyweight), blood was sampled every 20 min for 5 h to analyze GH, AA, insulin and glucose concentrations. The study was performed in eight healthy women (aged 19-26 years; body mass index 19-26 kg/m(2)) in a randomized, single blind, placebo-controlled crossover design.RESULTS: GH responses were more increased after ingestion of gelatine (8.2+/-1.1 microg/l) compared with ingestion of soy, alpha-lactalbumin and milk (5.0+/-0.8, 4.5+/-0.6 and 6.4+/-1.0 microg/l, respectively) (P<0.05). After ingestion of each protein, GH responses were higher compared with placebo ingestion (P<0.05). Simultaneously ingestion of gelatin resulted in the highest serum-arginine concentrations (ARG) compared with after ingestion of the other proteins (P<0.05). Insulin as well as glucose concentrations were not different after ingestion of the various proteins (P<0.05).CONCLUSIONS: The GH-promoting activity of protein depends on the protein source, in that, gelatin protein is the most potent GH stimulator. Arginine may be the responsible AA in the GH-promoting effect of gelatin, although each protein may have its own specific AA-spectrum involved in the stimulation of the somatotropic axis.
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| 5. |
- van Vught, A. J. A. H., et al.
(author)
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The effects of protein ingestion on GH concentrations in visceral obesity
- 2010
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In: Hormone and Metabolic Research. - : Georg Thieme Verlag KG. - 0018-5043 .- 1439-4286. ; 42:10, s. 740-745
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Journal article (peer-reviewed)abstract
- Growth hormone (GH), a hormone originating from the anterior pituitary gland, is an important regulator of metabolism and body composition. Low GH secretion is associated with features of the metabolic syndrome, in particular increased visceral body fat and decreased lean body mass. It has been shown that GH release can be promoted by ingestion of protein, in particular gelatin protein. The question remains; is the GH-promoting effect of gelatin protein also present in a population with blunted GH response, such as visceral obesity? 8 lean women (age: 23 +/- 3 years, BMI: 21.6 +/- 2.0 kg/m(2)) and 8 visceral obese women (age: 28 +/- 7 years, BMI: 33.8 +/- 5.5 kg/m(2)) were compared with regard to their 5-h GH response after oral ingestion of gelatin protein (0.6 g protein per kg bodyweight), placebo (water), or injection of growth hormone releasing hormone (GHRH) (1 mu/kg body weight), in a randomized crossover design. GH response after placebo, gelatin protein, or GHRH was higher in lean subjects than in visceral obese subjects (p < 0.05). Ingestion of gelatin protein increased GH response compared with placebo in both visceral obese (182.1 +/- 81.6 mu g/l.5h vs. 28.4 +/- 29.8 mu g/l.5h) and lean (631.7 +/- 144.2 mu g/l.5h vs. 241.0 +/- 196.8 mu g/l.5h) subjects (p < 0.05). GH response after ingestion of gelatin protein in visceral obese did not differ from that in lean, placebo-treated subjects (p = 0.45). GH concentrations after GHRH injection correlated significantly with GH concentrations after gelatin ingestion (AUC; r = 0.71, p < 0.01, Peak; r = 0.81, p < 0.01). Further research is needed to investigate if gelatin protein is able to improve metabolic abnormalities in hyposomatotropism in the long term or to investigate the relevance of protein as diagnostic tool in hyposomatotropism.
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| 6. |
- Soenen, Stijn, et al.
(author)
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Relationship between perilipin gene polymorphisms and body weight and body composition during weight loss and weight maintenance.
- 2009
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In: Physiology and Behavior. - 0031-9384 .- 1873-507X. ; 96:4-5
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Journal article (peer-reviewed)abstract
- BACKGROUND: Genetic variation in the perilipin (PLIN) gene may play a role in the etiology and treatment of obesity.OBJECTIVE: To examine different polymorphisms in the PLIN gene in relation to body-weight regulation.METHODS: 118 subjects followed a 6 wk VLCD, followed by 1 year weight maintenance. Body-weight (BW), body composition, leptin concentration, and polymorphisms of the PLIN gene: PLIN1:rs2289487, PLIN4:rs894160, PLIN6:rs1052700, PLIN5:rs2304795 and PLIN7:rs 2304796 were determined.RESULTS: BW loss during VLCD was 7.0+/-3.1 kg (p<0.05), and BW regain was 3.7+/-1.4 kg (p<0.05), including changes in body mass index (BMI), waist-circumference, body-composition and leptin concentrations (p<0.05). Linkage disequilibria were observed between PLIN1 and PLIN4: D' >0.9, r2=0.72; PLIN5 and PLIN7: D' >0.9, r2=0.85. In men, body weight, BMI, waist circumference, body fat, leptin concentrations were significantly lower for the haplotype of PLIN1 (C-alleles) and PLIN4 (A-alleles). In women weight loss and loss of fat mass were larger for the haplotype of PLIN1 (C-alleles) and PLIN4 (A-alleles). For PLIN6 genotypes body weight and body fat were lower for homozygotes of the minor allele (T/T) in the men; in the women leptin concentrations were lower. The haplotype of PLIN5 and PLIN7 consisting of A/G and G/G of PLIN5 and A/A of PLIN7 showed a reduction in FM: 5.9+/-0.6 kg vs 3.1+/-0.4 kg, % body fat: 5.5+/-0.6% vs 2.2+/-0.2%, and leptin: 20.5+/-10.8 ng/ml vs 12.9+/-6.7 ng/ml over time in the women (p<0.05).CONCLUSION: Since the haplotype of the minor alleles PLIN1-4, PLIN5-7 and PLIN6, was related to body-weight regulation at a lower level of body-weight in the men as well in the women we conclude that the PLIN1-4, 6, and 5-7 locus appears as a genetic influencer of obesity risk in humans.
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