Jose E Galgani1, Maria L Mizgier2, Andrea Mari3, Eric Ravussin4. 1. Departamento de Nutrición, Diabetes y Metabolismo, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile; UDA-Ciencias de la Salud, Carrera de Nutrición y Dietética, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile. Electronic address: jgalgani@uc.cl. 2. Departamento de Nutrición, Diabetes y Metabolismo, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile. 3. Istituto di Ingegneria Biomedica, Consiglio Nazionale delle Ricerche, Padova, Italy. 4. Pennington Biomedical Research Center, Baton Rouge, LA, USA.
Abstract
BACKGROUND: Glucose-stimulated insulin secretion correlates inversely with the degree of whole-body insulin sensitivity suggesting a crosstalk between peripheral organs and pancreas. Such sensing mechanism could be mediated by changes in glucose flux (uptake, oxidation or storage) in peripheral tissues that may drive insulin secretion. AIM: To relate whole-body non-protein respiratory quotient (npRQ), an index of macronutrient oxidative partitioning, with insulin secretion and β-cell function in non-diabetic individuals. METHODS: Macronutrient oxidation was measured after an overnight fast and for 4h after a 75-g oral glucose tolerance test (OGTT) in 30 participants (15/15 males/females; 35±12y; 27±4kg/m(2)). Furthermore, npRQ was assessed for 24h in a metabolic chamber. Insulin secretion was estimated by deconvolution of serum C-peptide concentration (fasting and 4-h OGTT) and from 24-h urinary C-peptide excretion corrected for energy intake (metabolic chamber). β-Cell function parameters were obtained by mathematical modeling, while insulin sensitivity was determined by a euglycemic-hyperinsulinemic clamp (120mU·m(-2)·min(-1)). RESULTS: Insulin secretion (from 24-h urinary C-peptide) correlated inversely with 24-h npRQ (r=-0.61; p=0.001), even after controlling for insulin sensitivity, energy balance, age and body mass index (r=-0.52; p=0.01). In turn, insulin secretion (from serum C-peptide) was not associated with fasting or OGTT npRQ. However, fasting npRQ was positively correlated with rate sensitivity (r=0.40; p<0.05) and marginally with glucose sensitivity (r=0.34; p=0.08). CONCLUSION: Macronutrient oxidative partitioning, specifically glucose oxidation, might play a role on the regulation of insulin secretion. Further studies should aim at identifying the signals linking these processes.
BACKGROUND:Glucose-stimulated insulin secretion correlates inversely with the degree of whole-body insulin sensitivity suggesting a crosstalk between peripheral organs and pancreas. Such sensing mechanism could be mediated by changes in glucose flux (uptake, oxidation or storage) in peripheral tissues that may drive insulin secretion. AIM: To relate whole-body non-protein respiratory quotient (npRQ), an index of macronutrient oxidative partitioning, with insulin secretion and β-cell function in non-diabetic individuals. METHODS: Macronutrient oxidation was measured after an overnight fast and for 4h after a 75-g oral glucose tolerance test (OGTT) in 30 participants (15/15 males/females; 35±12y; 27±4kg/m(2)). Furthermore, npRQ was assessed for 24h in a metabolic chamber. Insulin secretion was estimated by deconvolution of serum C-peptide concentration (fasting and 4-h OGTT) and from 24-h urinary C-peptide excretion corrected for energy intake (metabolic chamber). β-Cell function parameters were obtained by mathematical modeling, while insulin sensitivity was determined by a euglycemic-hyperinsulinemic clamp (120mU·m(-2)·min(-1)). RESULTS:Insulin secretion (from 24-h urinary C-peptide) correlated inversely with 24-h npRQ (r=-0.61; p=0.001), even after controlling for insulin sensitivity, energy balance, age and body mass index (r=-0.52; p=0.01). In turn, insulin secretion (from serum C-peptide) was not associated with fasting or OGTT npRQ. However, fasting npRQ was positively correlated with rate sensitivity (r=0.40; p<0.05) and marginally with glucose sensitivity (r=0.34; p=0.08). CONCLUSION: Macronutrient oxidative partitioning, specifically glucose oxidation, might play a role on the regulation of insulin secretion. Further studies should aim at identifying the signals linking these processes.
Authors: Jaehee Kim; ZiMian Wang; Steven B Heymsfield; Richard N Baumgartner; Dympna Gallagher Journal: Am J Clin Nutr Date: 2002-08 Impact factor: 7.045
Authors: I Zavaroni; G Deferrari; R Lugari; E Bonora; G Garibotto; E Dall'Aglio; C Robaudo; A Gnudi Journal: J Clin Endocrinol Metab Date: 1987-09 Impact factor: 5.958
Authors: Jose E Galgani; Carmen Gómez; Maria L Mizgier; Juan Gutierrez; Jose L Santos; Pablo Olmos; Andrea Mari Journal: PLoS One Date: 2016-12-21 Impact factor: 3.240
Authors: Maria L Mizgier; Luis R Cataldo; Juan Gutierrez; José L Santos; Mariana Casas; Paola Llanos; Ariel E Contreras-Ferrat; Cedric Moro; Karim Bouzakri; Jose E Galgani Journal: J Diabetes Res Date: 2017-02-14 Impact factor: 4.011
Authors: Maria L Mizgier; Rodrigo Fernández-Verdejo; Julien Cherfan; Michel Pinget; Karim Bouzakri; Jose E Galgani Journal: Front Physiol Date: 2019-08-08 Impact factor: 4.566