scholarly journals The Effect of Heat Stress on Respiratory Alkalosis and Insulin Sensitivity in Cinnamon Supplemented Pigs

Animals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 690
Author(s):  
Jeremy J. Cottrell ◽  
John B. Furness ◽  
Udani A. Wijesiriwardana ◽  
Mitchell Ringuet ◽  
Fan Liu ◽  
...  
Keyword(s):  
Heat Stress ◽  
Insulin Sensitivity ◽  
Heat Waves ◽  
Insulin Response ◽  
Respiratory Alkalosis ◽  
Tolerance Test ◽  
Intravenous Glucose Tolerance Test ◽  
Large White ◽  
Intravenous Glucose ◽  
Increase Insulin Sensitivity

With increases in the frequency, intensity and duration of heat waves forecast plus expansion of tropical agriculture, heat stress (HS) is both a current and an emerging problem. As cinnamon has been shown to increase insulin sensitivity, which is part of the adaptive response to HS, the aim of this experiment was to determine if cinnamon could improve insulin sensitivity and ameliorate HS in grower pigs. In a 2 × 2 factorial design, 36 female Large White × Landrace pigs were fed control (0%) vs. cinnamon (1.5%) diets and housed for 7 day under thermoneutral (20 °C, TN) vs. HS conditions (8 h 35 °C/16 h 28 °C, 35% relative humidity). At the completion of the challenge, insulin sensitivity was assessed by an intravenous glucose tolerance test (IVGTT). Heat stress increased parameters such as respiration rate and rectal temperature. Furthermore, biochemical changes in blood and urine indicated the pigs were experiencing respiratory alkalosis. Minimal modelling of parameters of insulin sensitivity showed that HS pigs had a lower insulin response to the IVGTT and improved insulin sensitivity. Cinnamon had additive effects with heat stress, reflected in lowering the insulin area under curve (AUC) and elevated insulin sensitivity compared to TN. However, this apparent improvement in insulin sensitivity did not ameliorate any of the other physiological symptoms of HS.

Modified protocols improve insulin sensitivity estimation using the minimal model

1987 ◽  
Vol 253 (6) ◽  
pp. E595-E602 ◽  
Author(s):  
Y. J. Yang ◽  
J. H. Youn ◽  
R. N. Bergman
Keyword(s):  
Standard Deviation ◽  
Insulin Sensitivity ◽  
Minimal Model ◽  
Insulin Response ◽  
Tolerance Test ◽  
Intravenous Glucose Tolerance Test ◽  
Improve Insulin Sensitivity ◽  
Intravenous Glucose ◽  
Sensitivity Estimation ◽  
Model Technique

We attempted to improve the precision of the estimation of insulin sensitivity (S1) from the minimal model technique by modifying insulin dynamics during a frequently sampled intravenous glucose tolerance test (FSIGT). Tolbutamide and somatostatin (SRIF) were used to change the insulin dynamics without directly affecting insulin sensitivity. Injection of tolbutamide (100 mg) at t = 20 min provoked an immediate secondary peak in insulin response, resulting in a greater integrated incremental insulin than the standard FSIGT. SRIF, injected at t = -1 min, delayed insulin secretion in proportion to the dose without any change in magnitude. Computer simulation was used to assess the precision of S1 estimation. Insulin dynamics from both standard and modified protocols were adjusted in magnitude, with the shape unchanged and analyzed to determine the effect of the magnitude of insulin response. Fractional standard deviation was reduced from 73% with the standard insulin profile to 23% with tolbutamide and 18% with the highest dose of SRIF. In addition, the fractional standard deviation of S1 estimates decreased exponentially with increasing magnitude of insulin response. Modified FSIGTs require a smaller insulin response than the standard protocol to achieve the same precision.

Relationship of insulin sensitivity to aerobic capacity in Standardbred mares and geldings

2005 ◽  
Vol 2 (3) ◽  
pp. 185-193 ◽  
Author(s):  
SE Pratt ◽  
RJ Geor ◽  
LJ McCutcheon
Keyword(s):  
Insulin Sensitivity ◽  
Aerobic Capacity ◽  
Serum Insulin ◽  
Insulin Response ◽  
Tolerance Test ◽  
Intravenous Glucose Tolerance Test ◽  
Glucose Disposal ◽  
Intravenous Glucose ◽  
Condition Score ◽  
Relationship Of

AbstractThe objective of this study was to determine the relationship between insulin sensitivity and aerobic capacity and serum adipocytokine (leptin, adiponectin) concentrations in 14 mature, unconditioned Standardbred horses (eight mares, six geldings). Each horse underwent a euglycaemic–hyperinsulinaemic clamp (EHC) and a frequently sampled intravenous glucose tolerance test (FSIGT) for assessment of insulin sensitivity. Aerobic capacity was determined by measurement of the peak rate of oxygen uptake (V˙O2peak) during an incremental exercise test (IET). Serum leptin and adiponectin concentrations were measured in baseline samples obtained before tests of insulin sensitivity. Mean body weight, condition score, V˙O2peak and run time during the IET did not differ between the sex groups. However, minimal model analysis of the FSIGT showed that insulin sensitivity (SI, ×10−4 l mU−1 min−1) was higher (P = 0.002) in geldings (4.21±0.78) than in mares (2.43±0.95), while the acute insulin response to glucose (AIRg) and glucose utilization independent of insulin (SG) were significantly higher in mares. Similarly, glucose uptake (M) per unit of serum insulin (I) during the EHC (M/I ratio) tended (P = 0.08) to be higher in geldings than in mares (×10−2 mg kg−1 min−1 per μU ml−1: 2.41±0.64 vs. 1.80±0.51). There was no significant relationship between V˙O2peak and measures of insulin sensitivity. Stepwise multiple linear regression modelling determined that sex (65%) and leptin concentrations (13.7%) accounted for 78.7% of the variance in SI, while 46% of the variance in M/I could be attributed to sex. It was concluded that aerobic capacity is not an important determinant of insulin-mediated glucose disposal in mature, untrained Standardbred horses. Further studies are needed to examine the influence of gender on insulin sensitivity in horses.

scholarly journals When MINMOD Artifactually Interprets Strong Insulin Secretion as Weak Insulin Action

2021 ◽  
Vol 12 ◽  
Author(s):  
Joon Ha ◽  
Ranganath Muniyappa ◽  
Arthur S. Sherman ◽  
Michael J. Quon
Keyword(s):  
Insulin Secretion ◽  
Insulin Sensitivity ◽  
Minimal Model ◽  
Insulin Response ◽  
Reference Method ◽  
Tolerance Test ◽  
Intravenous Glucose Tolerance Test ◽  
Intravenous Glucose ◽  
Model Studies ◽  
Increased Risk

We address a problem with the Bergman-Cobelli Minimal Model, which has been used for 40 years to estimate SI during an intravenous glucose tolerance test (IVGTT). During the IVGTT blood glucose and insulin concentrations are measured in response to an acute intravenous glucose load. Insulin secretion is often assessed by the area under the insulin curve during the first few minutes (Acute Insulin Response, AIR). The issue addressed here is that we have found in simulated IVGTTs, representing certain contexts, Minimal Model estimates of SI are inversely related to AIR, resulting in artifactually lower SI. This may apply to Minimal Model studies reporting lower SI in Blacks than in Whites, a putative explanation for increased risk of T2D in Blacks. The hyperinsulinemic euglycemic clamp (HIEC), the reference method for assessing insulin sensitivity, by contrast generally does not show differences in insulin sensitivity between these groups. The reason for this difficulty is that glucose rises rapidly at the start of the IVGTT and reaches levels independent of SI, whereas insulin during this time is determined by AIR. The minimal model in effect interprets this combination as low insulin sensitivity even when actual insulin sensitivity is unchanged. This happens in particular when high AIR results from increased number of readily releasable insulin granules, which may occur in Blacks. We conclude that caution should be taken when comparing estimates of SI between Blacks and Whites.

scholarly journals The Impact of Obesity On Insulin Sensitivity and Secretion During Pubertal Progression: A Longitudinal Study

2020 ◽  
Vol 105 (5) ◽  
pp. e2061-e2068 ◽  
Author(s):  
Megan M Kelsey ◽  
Laura Pyle ◽  
Allison Hilkin ◽  
Cameron D Severn ◽  
Kristina Utzschneider ◽  
...  
Keyword(s):  
Insulin Sensitivity ◽  
Insulin Response ◽  
Tolerance Test ◽  
Intravenous Glucose Tolerance Test ◽  
Normal Weight ◽  
Β Cell ◽  
Early Puberty ◽  
Intravenous Glucose ◽  
Increased Risk ◽  
The Impact

Abstract Context Physiologic changes in glucose metabolism are well-described to occur during puberty. However, there are important gaps in understanding the interaction between obesity and the normal physiologic changes during puberty, as well as how these changes could contribute to the increased risk of comorbidities, such as type 2 diabetes and dyslipidemia, in youth with obesity. Objective The objective of this study was to compare longitudinal changes in insulin sensitivity (Si) and secretion during pubertal progression in youth with obesity versus those with normal weight. Design Longitudinal observational study evaluating youth from early puberty (Tanner [T]2-T3) until puberty completion (T5). Setting Pediatric academic hospital Clinical Translational Research Center. Participants Pubertal youth with normal weight (n = 47; 22 female, 25 male) and obesity (n = 37; 23 female, 14 male) Main Outcome Measures Si, insulin response (acute insulin response to glucose, AIRg) and disposition index (DI) by intravenous glucose tolerance test at baseline (T2-T3), T4, and T5 Results Youth with obesity had significantly lower Si and higher AIRg at each time point (P < 0.001), but DI was similar between the groups. There were no group differences in trajectory of Si, AIRg or DI over time. Leptin, insulin-like growth factor-1, and obesity were most strongly associated with Si and AIRg at all time points. Conclusions Obesity significantly impacts Si during puberty, even at the earliest stages. However, in general, obese youth have adequate β-cell compensation for the significantly reduced Si of puberty. Future studies are needed to better predict the subset of youth who fail to maintain β-cell compensation during puberty.

scholarly journals Field Trial on Glucose-Induced Insulin Response in High-Yielding Dairy Cows under Different Environmental Temperatures

2017 ◽  
Vol 67 (3) ◽  
pp. 366-382
Author(s):  
Ivan Vujanac ◽  
Radiša Prodanović ◽  
Goran Korićanac ◽  
Jovan Bojkovski ◽  
Predrag Simeunović ◽  
...  
Keyword(s):  
Heat Stress ◽  
Glucose Tolerance ◽  
Milk Production ◽  
Basal Insulin ◽  
Insulin Response ◽  
Area Under The Curve ◽  
Tolerance Test ◽  
Intravenous Glucose Tolerance Test ◽  
Model Assessment ◽  
Intravenous Glucose

AbstractThis study aimed to evaluate glucose-induced insulin response in cows exposed to different temperature-humidity index. Twenty early lactating Holstein-Friesian cows were divided into 2 equal groups based on season, as summer (SU) and spring (SP). SP cows were not exposed to heat stress, while SU cows were exposed to moderate or severe heat stress. Milk production was recorded daily. Starting from day 30 of lactation, intravenous glucose tolerance test (IVGTT) was carried out three times at 30-day intervals. Blood samples were taken before (basal) and after glucose infusion, and glucose and insulin were measured at each sample point. The homeostatic model assessment (HOMA) index was calculated. Milk yield from days 30 to 40 and 64 to 90 of lactation were higher in SP cows than in SU cows. Basal glucose did not differ on days 30 and 60 of lactation, while basal insulin and HOMA were lower in SU compared to SP cows. On day 90 of lactation, SU cows had higher basal glucose, whereas basal insulin and HOMA did not differ. IVGTT results revealed that glucose tolerance was affected by heat stress such that SU cows had higher glucose clearance. Insulin responses to IVGTT did not differ on days 30 and 60 of lactation. Heat stress had a marked effect on insulin secretion on day 90 of lactation, illustrated by higher increments, peak concentrations and area under the curve for insulin in SU cows. Overall, season differences in glucose tolerance depend not only on heat stress and milk production but also on the stage of lactation.

scholarly journals First-phase insulin response (FPIR) to intravenous glucose tolerance test (IVGTT), insulin sensitivity and long-term follow-up in ?- transfusion-dependent thalassemia (TDT) normoglycemic patients with reduced insulin secretion to oral glucose tolerance t

2021 ◽  
Vol 13 (1) ◽  
pp. e2021021
Author(s):  
Vincenzo De Sanctis
Keyword(s):  
Insulin Sensitivity ◽  
Glucose Tolerance ◽  
Glucose Tolerance Test ◽  
Insulin Response ◽  
Tolerance Test ◽  
Intravenous Glucose Tolerance Test ◽  
Oral Glucose ◽  
Sensitivity Index ◽  
Intravenous Glucose

Summary. Objective: To  study the function of the endocrine pancreas in transfusion-dependent ?-thalassemia (?-TDT) patients with normal oral glucose tolerance test (OGTT) and hypoinsulinemia. Patients and methods: Seven ?-TDT patients  (mean age 22.4 ± 4.2 years) with normal glucose tolerance test (NGT) and poor insulin response (hypoinsulinemia) to OGTT,  not associated with ?-cell autoimmunity, were referred for a second opinion to an Italian Centre, part of the International Network of Clinicians for Endocrinopathies in Thalassemia and Adolescence Medicine (ICET-A). In this pilot study,  the first-phase insulin response (FPIR), expressed as the sum of 1 and  3 minutes insulin, of ?-TDT patients to intravenous glucose tolerance test (IVGTT), was tested. Moreover, the long-term natural history was followed prospectively using an annual OGTT, with the aim of detecting any abnormality of glucose metabolism. Results: The FPIR value  was between the 1st and 3rd percentile in two patients and between the 3rd and 10th percentile in  five. After 43 ± 26 months (range 11 - 80 months) of follow-up, 2 patients developed impaired glucose tolerance (IGT), 3 both IGT and impaired fasting glucose (IFG) and two overt diabetes mellitus (DM). Interestingly, the patients who developed DM had, at baseline the lowest value of insulinogenic index (IGI, 0.08 and 0.25), defined as the ratio of the increment of plasma insulin to plasma glucose during the first 30 minutes after OGTT. Moreover, a significant correlation was found between the IGI at baseline and at follow-up in the patients who developed IGT with or without IFG (R= 0.927; P: 0.023). A significant reduction of Matsuda insulin sensitivity index (ISIM) and Insulin Secretion-Sensitivity Index-2 (ISSI-2) was documented in the study cohort at diagnosis of IFG, IGT and DM. There was a significant inverse correlation between ISSI-2 and area under the curve of plasma glucose (AUC-PG). Conclusions: These data demonstrated, for the first time, a progressive deterioration in glucose homeostasis in ?-TDT subjects with NGT and hypoinsulinemia.  Thus, we consider that variations of insulin sensitivity could possibly have an impact on glucose tolerance in adult patients with TDT. Further investigations should focus on factors that might positively influence insulin sensitivity, including nutrition, drugs and physical activity.  

Hyperinsulinemic Compensation For Insulin Resistance Occurs Independent Of Elevated Glycemia In Male Dogs

Endocrinology ◽  
2021 ◽  
Author(s):  
Marilyn Ader ◽  
Richard N Bergman
Keyword(s):  
Insulin Resistance ◽  
Subcutaneous Fat ◽  
Insulin Response ◽  
Tolerance Test ◽  
Intravenous Glucose Tolerance Test ◽  
Intravenous Glucose ◽  
Primary Element ◽  
Subcutaneous Adiposity ◽  
Hyperinsulinemic Compensation

Abstract Insulin resistance (IR) engenders a compensatory increase in plasma insulin. Inadequate compensation is a primary element in the pathogenesis of Type 2 diabetes. The signal which heralds developing IR and initiates hyperinsulinemic compensation is not known. It has often been assumed to be increased glucose. We tested this assumption by determining whether development of fasting and/or glucose-stimulated hyperinsulinemia with diet-induced insulin resistance occurs because of concomitant elevation of glycemia. Male dogs (n=58) were fed a hypercaloric, fat-supplemented diet for 6 wks. Dogs underwent MRI to quantify total and regional (visceral, subcutaneous) adiposity as well as euglycemic hyperinsulinemic clamps. A subset of animals also underwent an insulin-modified intravenous glucose tolerance test (IVGTT) to assess insulin sensitivity, acute insulin response (AIRg), and glucose effectiveness. Fat feeding caused modest weight gain, increased visceral and subcutaneous fat, and IR at both peripheral and hepatic levels. Hyperinsulinemic compensation was observed in fasting levels as well as increased AIRg. However, we observed absolutely no increase in carefully measured fasting, evening (6-8 pm) or nocturnal glycemia (2-4 am). IR and hyperinsulinemia occurred despite no elevation in 24-hour glucose. Compensatory development of hyperinsulinemia during diet-induced insulin resistance occurs without elevated fasting or 24-hour glycemia. These data refute the idea that glucose itself is a requisite signal for β-cell upregulation. Alternative feedback mechanisms need to be identified.

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