Determining insulin sensitivity from glucose tolerance tests in Iberian and landrace pigs

Abstract

As insulin sensitivity may help to explain divergences in growth and body composition between native and modern breeds, metabolic responses to glucose infusion were measured using an intra-arterial glucose tolerance test (IAGTT). Iberian (n = 4) and Landrace (n = 5) barrows (47.0 ± 1.2 kg body weight (BW)), fitted with a permanent carotid artery catheter were injected with glucose (500 mg/kg BW) and blood samples collected at -10, 0, 5, 10, 15, 20, 25, 30, 45, 60, 90, 120 and 180 min following glucose infusion. Plasma samples were analysed for insulin, glucose, lactate, triglycerides, cholesterol, creatinine, albumin and urea. Insulin sensitivity indices were calculated and analysed. Mean plasma glucose, creatinine and cholesterol concentrations were lower (P < 0.01) in Iberian (14, 68 and 22%, respectively) than in Landrace pigs during the IAGTT. However, mean plasma insulin, lactate, triglycerides and urea concentrations were greater (P < 0.001) in Iberian (50, 35, 18 and 23%, respectively) than in Landrace pigs. Iberian pigs had larger area under the curve (AUC) of insulin (P < 0.05) or tended to a greater AUC of lactate (P < 0.10), and a smaller (P < 0.05) AUC for glucose 0-60 min compared with Landrace pigs. Indices for estimating insulin sensitivity in fasting conditions indicated improved β-cell function in Iberian compared with Landrace pigs, but no difference (P > 0.10) in calculated insulin sensitivity index was found after IAGTT between breeds. A time response (P < 0.05) was obtained for insulin, glucose and lactate so that maximum concentration was achieved at 10 and 15 min post-infusion for insulin (Iberian and Landrace pigs, respectively), immediately post-infusion for glucose, and 20 min post-infusion for lactate, decreasing thereafter until basal levels. There was no time effect for the rest of metabolites evaluated. In conclusion, growing Iberian pigs challenged with an IAGTT showed changes in biochemical parameters and insulin response that may indicate an early stage of insulin resistance.

UPLC-Orbitrap-MS/MS Combined With Biochemical Analysis to Determine the Growth and Development of Mothers and Fetuses in Different Gestation Periods on Tibetan Sow Model

“…Interestingly, our findings were in direct contrast with other studies about other high-yield sows ( 24 – 26 ), implying that the Tibetan sows might have no or limited insulin resistance in the late gestation period. We speculated that Tibetan pigs, as lean pigs, had higher insulin sensitivity or stronger glucose tolerance than other obese pig breeds, which can be supported by previous reports that lean pigs had higher insulin sensitivity and glucose tolerance than obese pigs ( 27 , 28 ).…”

High fat diet is associated with gut microbiota dysbiosis and decreased gut microbial derived metabolites related to metabolic health in young Göttingen Minipigs

“…For IVGTT data, insulin sensitivity index was calculated using a non-linear mixed effect approach for minimal model-derived insulin sensitivity index (SI) and glucose-mediated glucose clearance (SG) [29,30]. Homeostatic model assessment of insulin resistance (HOMA-IR) was calculated based on fasting glucose and insulin values from the IVGTT according to the following formula: HOMA-IR = fasting plasma glucose [mM] x fasting plasma insulin [μU/ml]/ 22.5 [31]. The Matsuda insulin sensitivity index [32] was calculated for the IVGTT using time 0, 30, 60 and 120 minutes.…”

Insulin sensitivity is associated with the observed variation of de novo lipid synthesis and body composition in finishing pigs

“…Some studies have reported greater postprandial serum levels of insulin in obese pig lines than in lean lines 15,16 , and others have reported different insulin sensitivities between these lines 17 . For example, Iberian pigs, which are considered an obese genetic line had lower whole-body insulin sensitivity but increased β-cell function compared with lean Landrace pigs 17 .…”

“…Some studies have reported greater postprandial serum levels of insulin in obese pig lines than in lean lines 15,16 , and others have reported different insulin sensitivities between these lines 17 . For example, Iberian pigs, which are considered an obese genetic line had lower whole-body insulin sensitivity but increased β-cell function compared with lean Landrace pigs 17 . Although insulin sensitivity has been considered when comparing insulin responses between breeds, little is known about the relationship of insulin sensitivity with the observed variations Trial 1.…”