scholarly journals Increased postprandial nonesterified fatty acid efflux from adipose tissue in prediabetes is offset by enhanced dietary fatty acid adipose trapping

Author(s):  
Émilie Montastier ◽  
Run Zhou Ye ◽  
Christophe Noll ◽  
Lucie Bouffard ◽  
Mélanie Fortin ◽  
...  

The mechanism of increased postprandial nonesterified fatty acid (NEFA) appearance in the circulation in impaired glucose tolerance (IGT) is due to increased adipose tissue lipolysis but could also be contributed to by reduced adipose tissue (AT) dietary fatty acid (DFA) trapping and increased 'spillover' into the circulation. Thirty-one subjects with IGT (14 women, 17 men) and 29 with normal glucose tolerance (NGT, 15 women, 14 men) underwent a meal test with oral and intravenous palmitate tracers and the oral [18F]-fluoro-thia-heptadecanoic acid positron emission tomography method. Postprandial palmitate appearance (Rapalmitate) was higher in IGT vs. NGT (P < 0.001), driven exclusively by Rapalmitate from obesity-associated increase in intracellular lipolysis (P = 0.01), as Rapalmitate from DFA spillover was not different between the groups (P = 0.19) and visceral AT DFA trapping was even higher in IGT vs. NGT (P = 0.02). Plasma glycerol appearance was lower in IGT (P = 0.01), driven down by insulin resistance and increased insulin secretion. Thus, we found higher AT DFA trapping, limiting spillover to lean organs and in part offsetting the increase in Rapalmitate from intracellular lipolysis. Whether similar findings occur in frank diabetes, a condition also characterized by insulin resistance but relative insulin deficiency, requires further investigation (Clinicaltrials.gov: NCT04088344, NCT02808182).

1973 ◽  
Vol 72 (3) ◽  
pp. 475-494 ◽  
Author(s):  
Svein Oseid

ABSTRACT Six cases of congenital generalized lipodystrophy have been studied at different ages from infancy to adolescence with regard to glucose tolerance, insulin secretion, and insulin sensitivity. During the first few years of life there is normal glucose tolerance. The fasting immuno-reactive insulin (IRI) levels are either slightly elevated or normal. The IRI response to glucose is exaggerated and prolonged, at least from the third year of life. Some degree of insulin resistance is already present in infancy. From the age of 8–10 years glucose tolerance decreases rapidly. The fasting IRI levels are usually grossly elevated, while fasting plasma glucose levels are only moderately elevated or normal. The IRI responses to oral and iv administered glucose, and to tolbutamide are exaggerated; the insulinogenic indices are high. Cortisone primed glucose tolerance tests become abnormal. Insulin resistance is marked, and increases with age. After cessation of growth at approximately 12 years of age, frank diabetes with fasting hyperglycaemia and diabetic glucose tolerance curves developed in the one patient followed beyond this age. Her fasting IRI was increased, but there was a poor IRI response to glucose stimulation, suggesting a partial exhaustion of the β-cells. Her initial IRI response to tolbutamide was still good, but not as brisk as in the younger patients. This type of diabetes is quite different from the juvenile form, and also from the diabetes of older age. It may be causally related to the lack of an adequate adipose organ necessary for the disposal of excesses of glucose, or possibly related to another anti-insulin mechanism.


2018 ◽  
Vol 50 (05) ◽  
pp. 408-413 ◽  
Author(s):  
Sema Dogansen ◽  
Gulsah Yalin ◽  
Seher Tanrikulu ◽  
Sema Yarman

AbstractIn this study, we aimed to evaluate the presence of glucose metabolism abnormalities and their impact on IGF-1 levels in patients with acromegaly. Ninety-three patients with acromegaly (n=93; 52 males/41 females) were included in this study. Patients were separated into three groups such as; normal glucose tolerance (n=23, 25%), prediabetes (n=38, 41%), and diabetes mellitus (n=32, 34%). Insulin resistance was calculated with homeostasis model assessment (HOMA). HOMA-IR > 2.5 or ≤2.5 were defined as insulin resistant or noninsulin resistant groups, respectively. Groups were compared in terms of factors that may be associated with glucose metabolism abnormalities. IGF-1% ULN (upper limit of normal)/GH ratios were used to evaluate the impact of glucose metabolism abnormalities on IGF-1 levels. Patients with diabetes mellitus were significantly older with an increased frequency of hypertension (p<0.001, p=0.01, respectively). IGF-1% ULN/GH ratio was significantly lower in prediabetes group than in normal glucose tolerance group (p=0.04). Similarly IGF-1% ULN/GH ratio was significantly lower in insulin resistant group than in noninsulin resistant group (p=0.04). Baseline and suppressed GH levels were significantly higher in insulin resistant group than in noninsulin resistant group (p=0.024, p<0.001, respectively). IGF-1% ULN/GH ratio is a useful marker indicating glucose metabolism disorders and IGF-1 levels might be inappropriately lower in acromegalic patients with insulin resistance or prediabetes. We suggest that IGF-1 levels should be re-evaluated after the improvement of insulin resistance or glycemic regulation for the successful management of patients with acromegaly.


PPAR Research ◽  
2016 ◽  
Vol 2016 ◽  
pp. 1-7
Author(s):  
Jia Liu ◽  
Rui Lu ◽  
Ying Wang ◽  
Yanjin Hu ◽  
Yumei Jia ◽  
...  

Hypertriglyceridemia is an important risk factor associated with insulin resistance andβ-cell dysfunction. This study investigated the effects of hypertriglyceridemia and fenofibrate treatment on insulin sensitivity andβ-cell function in subjects with normal glucose tolerance. A total of 1974 subjects with normal glucose tolerance were divided into the normal TG group (NTG group,n=1302) and hypertriglyceridemia group (HTG group,n=672). Next, 92 patients selected randomly from 672 patients with hypertriglyceridemia were assigned to a 24-week fenofibrate treatment. The HTG group had increased waist circumference (WC), body mass index (BMI), homeostasis model assessment of insulin resistance (HOMA-IR), and homeostasis model assessment ofβ-cell function (HOMA-β) and decreased high-density lipoprotein cholesterol (HDL-C) compared with the NTG group (allP<0.01). The 24-week fenofibrate treatment significantly decreased the WC, BMI, TG, HOMA-IR, and HOMA-βlevels and increased the HDL-C levels in the patients with hypertriglyceridemia (WC, BMI, and HOMA-IR:P<0.05; TG, HDL-C, and HOMA-β:P<0.01). The fenofibrate treatment significantly alleviated insulin resistance and reduced the secreting load ofβ-cells in the hypertriglyceridemia patients with normal glucose tolerance.


2019 ◽  
Vol 18 (1) ◽  
Author(s):  
Ferdinando Carlo Sasso ◽  
Pia Clara Pafundi ◽  
Raffaele Marfella ◽  
Paolo Calabrò ◽  
Federico Piscione ◽  
...  

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