Weight loss is linearly associated with a reduction of the insulin response to an oral glucose test in Icelandic horses

Abstract Background The oral glucose test (OGT) is a useful tool for diagnosing insulin dysregulation (ID) and is somewhat repeatable in ponies under consistent management. This study aimed to determine whether the insulin and incretin responses to an OGT in ponies differed after short-term access to fertilised pasture, compared to unfertilised pasture, by using a randomised, repeated measures study design. Sixteen mixed-breed ponies were classified as severely insulin-dysregulated (SD; post-prandial insulin ≥80 μIU/mL) or not severely insulin-dysregulated (NSD; post-prandial insulin < 80 μIU/mL) using an OGT prior to the study. The ponies accessed pasture that was fertilised, or unfertilised, for 5 days (4 h/day, with supplemental hay provided at 0.7% bodyweight), with a 10 day period between phases. An OGT was performed after each phase. Glucose, insulin, active glucagon-like peptide-1 (aGLP-1), and glucose-dependent insulinotropic polypeptide (GIP) were measured in post-prandial blood samples. Results The volume of fertilised pasture was five-fold greater than unfertilised pasture, with % non-structural carbohydrates (NSC) similar between all forages. Consuming fertilised pasture increased (P = 0.018) the serum insulin response to an OGT, compared to grazing unfertilised pasture. A limitation of the study was that pasture intake was unable to be quantified. Insulin responses were greater in SD, compared to NSD, ponies (P < 0.001) and remained well above the test cut-off at all times. A subset of ponies, initially screened as NSD, became (more) insulin-dysregulated after pasture access. Further, aGLP-1 was a significant predictor of insulin concentration in this cohort. Conclusions Whereas some insulin-dysregulated ponies were comparatively resistant to dietary intervention, others showed markedly different OGT responses following subtle changes in their forage-based diet. This implies that mild/early ID might be unmasked by dietary change, and that dietary management is important in these ponies. However, dietary management alone may not be adequate for all cases of ID.

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Asians React Differently to Oral Glucose Test

Ob Gyn News ◽

10.1016/s0029-7437(05)70182-8 ◽

2005 ◽

Vol 40 (8) ◽

pp. 15

Author(s):

TIMOTHY F. KIRN

Keyword(s):

Oral Glucose ◽

Glucose Test ◽

Oral Glucose Test

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Oral Glucose Test Advised For ‘Prediabetes’ Screening

Family Practice News ◽

10.1016/s0300-7073(07)70399-7 ◽

2007 ◽

Vol 37 (7) ◽

pp. 1-17

Author(s):

MIRIAM E. TUCKER

Keyword(s):

Oral Glucose ◽

Glucose Test ◽

Oral Glucose Test

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Simple Parameters Describing Gut Absorption and Lipid Dynamics in Relation to Glucose Metabolism During a Routine Oral Glucose Test

Data-driven Modeling for Diabetes - Lecture Notes in Bioengineering ◽

10.1007/978-3-642-54464-4_7 ◽

2014 ◽

pp. 151-163

Author(s):

Andrea Tura ◽

Giovanni Pacini

Keyword(s):

Glucose Metabolism ◽

Oral Glucose ◽

Lipid Dynamics ◽

Glucose Test ◽

Oral Glucose Test

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The Release of Gastric Inhibitory Peptide, Glucagon-Like Peptide-I, and Insulin after Oral Glucose Test in Colectomized Subjects

Scandinavian Journal of Gastroenterology ◽

10.3109/00365529709025084 ◽

1997 ◽

Vol 32 (5) ◽

pp. 473-477 ◽

Cited By ~ 16

Author(s):

C. Palnæs Hansen ◽

J. J. Andreasen ◽

J. J. Holst

Keyword(s):

Oral Glucose ◽

Inhibitory Peptide ◽

Gastric Inhibitory Peptide ◽

Glucose Test ◽

Oral Glucose Test ◽

Glucagon Like Peptide

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The repeatability of an oral glucose test in ponies

Equine Veterinary Journal ◽

10.1111/evj.12579 ◽

2016 ◽

Vol 49 (2) ◽

pp. 238-243 ◽

Cited By ~ 22

Author(s):

M. A. de Laat ◽

M. N. Sillence

Keyword(s):

Oral Glucose ◽

Glucose Test ◽

Oral Glucose Test

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Metabolic impact of weight variations in Icelandic horses

PeerJ ◽

10.7717/peerj.10764 ◽

2021 ◽

Vol 9 ◽

pp. e10764

Author(s):

Julien Delarocque ◽

Florian Frers ◽

Korinna Huber ◽

Klaus Jung ◽

Karsten Feige ◽

...

Keyword(s):

Weight Gain ◽

Linear Models ◽

Metabolic Response ◽

Insulin Response ◽

Oral Glucose ◽

Insulin Dysregulation ◽

One Year ◽

Rotation Set ◽

The Relationship ◽

Icelandic Horses

Background Insulin dysregulation (ID) is an equine endocrine disorder, which is often accompanied by obesity and various metabolic perturbations. The relationship between weight variations and fluctuations of the insulin response to oral glucose tests (OGT) as well as the metabolic impact of ID have been described previously. The present study seeks to characterize the concomitant metabolic impact of variations in the insulin response and bodyweight during repeated OGTs using a metabolomics approach. Methods Nineteen Icelandic horses were subjected to five OGTs over one year and their bodyweight, insulin and metabolic response were monitored. Analysis of metabolite concentrations depending on time (during the OGT), relative bodyweight (rWeight; defined as the bodyweight at one OGT divided by the mean bodyweight across all OGTs) and relative insulin response (rAUCins; defined accordingly from the area under the insulin curve during OGT) was performed using linear models. Additionally, the pathways significantly associated with time, rWeight and rAUCins were identified by rotation set testing. Results The results suggested that weight gain and worsening of ID activate distinct metabolic pathways. The metabolic profile associated with weight gain indicated an increased activation of arginase, while the pathways associated with time and rAUCins were consistent with the expected effect of glucose and insulin, respectively. Overall, more metabolites were significantly associated with rWeight than with rAUCins.

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