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Anderwald CH, Tura A, Gessl A, Smajis S, Bieglmayer C, Marculescu R, Luger A, Pacini G, Krebs M. Whole-body insulin sensitivity rather than body-mass-index determines fasting and post-glucose-load growth hormone concentrations. PLoS One 2014; 9:e115184. [PMID: 25517727 PMCID: PMC4269423 DOI: 10.1371/journal.pone.0115184] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Accepted: 11/19/2014] [Indexed: 11/25/2022] Open
Abstract
Background Obese, non-acromegalic persons show lower growth hormone (GH) concentrations at fasting and reduced GH nadir during an oral glucose tolerance test (OGTT). However, this finding has never been studied with regard to whole-body insulin-sensitivity as a possible regulator. Methods In this retrospective analysis, non-acromegalic (NonACRO, n = 161) and acromegalic (ACRO, n = 35), non-diabetic subjects were subdivided into insulin-sensitive (IS) and –resistant (IR) groups according to the Clamp-like Index (CLIX)-threshold of 5 mg·kg−1·min−1 from the OGTT. Results Non-acromegalic IS (CLIX: 8.8±0.4 mg·kg−1·min−1) persons with similar age and sex distribution, but lower (p<0.001) body-mass-index (BMI = 25±0 kg/m2, 84% females, 56±1 years) had 59% and 70%, respectively, higher (p<0.03) fasting GH and OGTT GH area under the curve concentrations than IR (CLIX: 3.5±0.1 mg·kg−1·min−1, p<0.001) subjects (BMI = 29±1 kg/m2, 73% females, 58±1 years). When comparing on average overweight non-acromegalic IS and IR with similar anthropometry (IS: BMI: 27±0 kg/m2, 82% females, 58±2 years; IR: BMI: 27±0 kg/m2, 71% females, 60±1 years), but different CLIX (IS: 8.7±0.9 vs. IR: 3.8±0.1 mg·kg−1·min−1, p<0.001), the results remained almost the same. In addition, when adjusted for OGTT-mediated glucose rise, GH fall was less pronounced in IR. In contrast, in acromegalic subjects, no difference was found between IS and IR patients with regard to fasting and post-glucose-load GH concentrations. Conclusions Circulating GH concentrations at fasting and during the OGTT are lower in non-acromegalic insulin-resistant subjects. This study seems the first to demonstrate that insulin sensitivity rather than body-mass modulates fasting and post-glucose-load GH concentrations in non-diabetic non–acromegalic subjects.
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Affiliation(s)
- Christian-Heinz Anderwald
- Division of Endocrinology and Metabolism, Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria
- Metabolic Unit, Institute of Biomedical Engineering, National Research Council (ISIB-CNR), Padua, Italy
- Mariahilf Community Pharmacy, Arnoldstein, Austria
- Medical Direction, Specialized Hospital Complex Agathenhof, Micheldorf, Austria
- * E-mail:
| | - Andrea Tura
- Metabolic Unit, Institute of Biomedical Engineering, National Research Council (ISIB-CNR), Padua, Italy
| | - Alois Gessl
- Division of Endocrinology and Metabolism, Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria
| | - Sabina Smajis
- Division of Endocrinology and Metabolism, Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria
| | - Christian Bieglmayer
- Clinical Institute of Medical and Chemical Laboratory Diagnostics, Medical University of Vienna, Vienna, Austria
| | - Rodrig Marculescu
- Clinical Institute of Medical and Chemical Laboratory Diagnostics, Medical University of Vienna, Vienna, Austria
| | - Anton Luger
- Division of Endocrinology and Metabolism, Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria
| | - Giovanni Pacini
- Metabolic Unit, Institute of Biomedical Engineering, National Research Council (ISIB-CNR), Padua, Italy
| | - Michael Krebs
- Division of Endocrinology and Metabolism, Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria
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Anderwald CH, Tura A, Gessl A, Luger A, Pacini G, Krebs M. Adequately adapted insulin secretion and decreased hepatic insulin extraction cause elevated insulin concentrations in insulin resistant non-diabetic adrenal incidentaloma patients. PLoS One 2013; 8:e77326. [PMID: 24146977 PMCID: PMC3797754 DOI: 10.1371/journal.pone.0077326] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Accepted: 09/08/2013] [Indexed: 11/19/2022] Open
Abstract
Background Insulin-resistance is commonly found in adrenal incidentaloma (AI) patients. However, little is known about beta-cell secretion in AI, because comparisons are difficult, since beta–cell-function varies with altered insulin-sensitivity. Objectives To retrospectively analyze beta–cell function in non-diabetic AI, compared to healthy controls (CON). Methods AI (n=217, 34%males, 57±1years, body-mass-index:27.7±0.3kg/m2) and CON [n=25, 32%males, 56±1years, 26.7±0.8kg/m2] with comparable anthropometry (p≥0.31) underwent oral-glucose-tolerance-tests (OGTTs) with glucose, insulin, and C–peptide measurements. 1mg-dexamethasone-suppression-tests were performed in AI. AI were divided according to post–dexamethasone-suppression–test cortisol-thresholds of 1.8 and 5µg/dL into 3subgroups: pDexa<1.8µg/dL, pDexa1.8-5µg/dL and pDexa>5µg/dL. Using mathematical modeling, whole-body insulin-sensitivity [Clamp-like-Index (CLIX)], insulinogenic Index, Disposition Index, Adaptation Index, and hepatic insulin extraction were calculated. Results CLIX was lower in AI combined (4.9±0.2mg·kg-1·min-1), pDexa<1.8µg/dL (4.9±0.3) and pDexa1.8-5µg/dL (4.7±0.3, p<0.04 vs.CON:6.7±0.4). Insulinogenic and Disposition Indexes were 35%–97% higher in AI and each subgroup (p<0.008 vs.CON), whereas C–peptide–derived Adaptation Index, compensating for insulin-resistance, was comparable between AI, subgroups, and CON. Mathematical estimation of insulin–derived (insulinogenic and Disposition) Indexes from associations to insulin-sensitivity in CON revealed that AI-subgroups had ~19%-32% higher insulin-secretion than expectable. These insulin-secretion-index differences negatively (r=-0.45, p<0.001) correlated with hepatic insulin extraction, which was 13-16% lower in AI and subgroups (p<0.003 vs.CON). Conclusions AI-patients show insulin-resistance, but adequately adapted insulin secretion with higher insulin concentrations during an OGTT, because of decreased hepatic insulin extraction; this finding affects all AI-patients, regardless of dexamethasone-suppression-test outcome.
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Affiliation(s)
- Christian-Heinz Anderwald
- Division of Endocrinology and Metabolism, Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria
- Metabolic Unit, Institute of Biomedical Engineering, National Research Council (ISIB-CNR), Padua, Italy
- Mariahilf Community Pharmacy, Arnoldstein, Austria
- Medical Direction, Specialized Hospital Complex Agathenhof, Micheldorf, Austria
- * E-mail:
| | - Andrea Tura
- Metabolic Unit, Institute of Biomedical Engineering, National Research Council (ISIB-CNR), Padua, Italy
| | - Alois Gessl
- Division of Endocrinology and Metabolism, Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria
| | - Anton Luger
- Division of Endocrinology and Metabolism, Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria
| | - Giovanni Pacini
- Metabolic Unit, Institute of Biomedical Engineering, National Research Council (ISIB-CNR), Padua, Italy
| | - Michael Krebs
- Division of Endocrinology and Metabolism, Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria
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Anderwald C, Tura A, Winhofer Y, Krebs M, Winzer C, Bischof MG, Luger A, Pacini G, Kautzky-Willer A. Glucose absorption in gestational diabetes mellitus during an oral glucose tolerance test. Diabetes Care 2011; 34:1475-80. [PMID: 21602425 PMCID: PMC3120199 DOI: 10.2337/dc10-2266] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVE Women with gestational diabetes mellitus (GDM) show reduced insulin sensitivity and markedly elevated glucose excursions. After delivery, GDM mostly reverts to normal glucose tolerance (NGT), although leaving an increased risk of type 2 diabetes. Because gastrointestinal function changes during pregnancy causing vomiting, constipation, or reduced motility, we thought that gut glucose absorption in GDM or pregnancy might be altered to affect circulating glucose excursions. RESEARCH DESIGN AND METHODS By undergoing 180-min oral glucose tolerance tests (OGTTs), pregnant women with GDM (GDMpreg; n=15, BMI=32±2 kg/m2, aged 33±1 years) were compared with NGT women (NGTpreg; n=7, BMI=28±1 kg/m2, aged 34±2 years), matching for major anthropometric characteristics (each P>0.2). After delivery (6-7 months later), both groups were studied the same way. We computed and mathematically modeled gut glucose absorption from insulin-mediated glucose disappearance and endogenous glucose production (EGP). Whole-body insulin sensitivity was calculated using the Clamp-like Index. RESULTS GDMpreg showed 16-25% higher plasma glucose concentrations (P<0.04) during the final 2 h of OGTT, similar EGP, but lower (P<0.01) insulin sensitivity (2.7±0.2 mg·kg(-1)·min(-1) vs. NGTpreg: 4.5±0.8 mg·kg(-1)·min(-1)). In GDMpreg, gut glucose absorption rates were ≤52% lower from 30 to 120 min (P<0.03 vs. conditions after delivery or NGTpreg). In contrast, glucose absorption rates in NGTpreg were comparable during and after pregnancy. None of the studied women developed diabetes after delivery. CONCLUSIONS In GDMpreg, OGTT gut glucose absorption is markedly lower during hyperglycemia, whereas both glycemia and glucose absorption in NGTpreg are comparable between pregnant and postpartum states. Thus, hyperglycemia in GDM does not seem to result from too rapid or increased glucose absorption.
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Affiliation(s)
- Christian Anderwald
- Department of Internal Medicine III, Medical University of Vienna, and Medical Direction, St. Elisabeth Hospital, Vienna, Austria.
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Bibliography. Current world literature. Adrenal cortex. Curr Opin Endocrinol Diabetes Obes 2011; 18:231-3. [PMID: 21522003 DOI: 10.1097/med.0b013e3283457c7d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Anderwald C, Gastaldelli A, Tura A, Krebs M, Promintzer-Schifferl M, Kautzky-Willer A, Stadler M, DeFronzo RA, Pacini G, Bischof MG. Mechanism and effects of glucose absorption during an oral glucose tolerance test among females and males. J Clin Endocrinol Metab 2011; 96:515-24. [PMID: 21147888 DOI: 10.1210/jc.2010-1398] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
BACKGROUND Several epidemiological studies revealed sex-specific differences during oral glucose tolerance tests (OGTTs), such as higher prevalence of glucose intolerance (i.e. increased glucose at the end of the OGTT) in females, which was not yet explained. Thus, we aimed to analyze sex-related distinctions on OGTT glucose metabolism, including gut absorption, in healthy humans. METHODS Females (n = 48) and males (n = 26) with comparable age (females, 45 ± 1 yr; males, 44 ± 2 yr) and body mass index (both, 25 ± 1 kg/m(2)) but different height (females, 166 ± 1 cm; males, 180 ± 2 cm; P < 0.000001), all normally glucose tolerant, as tested by frequently sampled, 3-h (75-g) OGTTs, underwent hyperinsulinemic [40 mU/(min · m(2))] isoglycemic clamp tests with simultaneous measurement of endogenous glucose (d-[6,6-(2)H(2)]glucose) production (EGP). EGP and glucose disappearance during OGTT were calculated from logarithmic relationships with clamp test insulin concentrations. After reliable model validation by double-tracer technique (r = 0.732; P < 0.007), we calculated and modeled gut glucose absorption (ABS). RESULTS Females showed lower (P < 0.05) fasting EGP [1.4 ± 0.1 mg/(kg · min)] than males [1.7 ± 0.1 mg/(kg · min)] but comparable whole-body insulin sensitivity in clamp tests [females, 8.1 ± 0.4 mg/(kg · min); males, 8.3 ± 0.6 mg/(kg · min)]. Plasma glucose OGTT concentrations were higher (P < 0.04) from 30-40 min in males but from 120-180 min in females. Glucose absorption rates were 21-46% increased in the initial 40 min in males but in females by 27-40% in the third hour (P < 0.05). Gut glucose half-life was markedly higher in females (79 ± 2 min) than in males (65 ± 3 min, P < 0.0001) and negatively related to body height (r = -0.481; P < 0.0001). CONCLUSIONS This study in healthy, glucose-tolerant humans shows for the first time different ABS rates during OGTT in women and men and a negative relationship between body height and gut glucose half-life. Prolonged ABS in females might therefore contribute to higher plasma glucose concentrations at the end of OGTT.
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Affiliation(s)
- Christian Anderwald
- Division of Endocrinology and Metabolism, Department of Internal Medicine III, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna, Austria.
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Anderwald C, Tura A, Grassi A, Krebs M, Szendroedi J, Roden M, Bischof MG, Luger A, Pacini G. Insulin infusion during normoglycemia modulates insulin secretion according to whole-body insulin sensitivity. Diabetes Care 2011; 34:437-41. [PMID: 21216852 PMCID: PMC3024363 DOI: 10.2337/dc10-1137] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVE Glucose is the major stimulus for insulin release. Time course and amount of insulin secreted after glycemic stimulus are different between type 2 diabetes mellitus (T2DM) patients and healthy subjects. In rodents, it was demonstrated that insulin can modulate its own release. Previous studies in humans yielded contrasting results: Insulin was shown to have an enhancing effect, no effect, or a suppressive effect on its own secretion. Thus, we aimed to evaluate short-term effects of human insulin infusion on insulin secretion during normoglycemia in healthy humans and T2DM subjects of both sex. RESEARCH DESIGN AND METHODS Hyperinsulinemic-isoglycemic clamps with whole-body insulin-sensitivity (M) and C-peptide measurements for insulin secretion modeling were performed in 65 insulin-sensitive (IS) subjects (45 ± 1 year, BMI: 24.8 ± 0.5 kg/m(2)), 17 insulin-resistant (IR) subjects (46 ± 2 years, 28.1 ± 1.3 kg/m(2)), and 20 T2DM patients (56 ± 2 years, 28.0 ± 0.8 kg/m(2); HbA(1c) = 6.7 ± 0.1%). RESULTS IS subjects (M = 8.8 ± 0.3 mg · min(-1) · kg(-1)) had higher (P < 0.00001) whole-body insulin sensitivity than IR subjects (M = 4.0 ± 0.2) and T2DM patients (M = 4.3 ± 0.5). Insulin secretion profiles during clamp were different (P < 0.00001) among the groups, increasing in IS subjects (slope: 0.56 ± 0.11 pmol/min(2)) but declining in IR (-0.41 ± 0.14) and T2DM (-0.87 ± 0.12, P < 0.00002 IR and T2DM vs. IS) subjects. Insulin secretion changes during clamp directly correlated with M (r = 0.6, P < 0.00001). CONCLUSIONS Insulin release during normoglycemia can be modulated by exogenous insulin infusion and directly depends on whole-body insulin sensitivity. Thus, in highly sensitive subjects, insulin increases its own secretion. On the other hand, a suppressive effect of insulin on its own secretion occurs in IR and T2DM subjects.
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Affiliation(s)
- Christian Anderwald
- Metabolic Unit, Institute of Biomedical Engineering, National Research Council, Padova, Italy.
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