scholarly journals Acute effects of the food preservative propionic acid on glucose metabolism in humans

2021 ◽  
Vol 9 (1) ◽  
pp. e002336
Author(s):  
Gail K Adler ◽  
Ezra S Hornik ◽  
Gillian Murray ◽  
Shreya Bhandari ◽  
Yogesh Yadav ◽  
...  

IntroductionPropionic acid (PA) is a common food preservative generally recognized as safe by the US Food and Drug Administration; however, exogenous PA has effects on glucose metabolism that are not fully understood. Our preclinical studies demonstrated exogenous PA increases glucagon, norepinephrine, and endogenous glucose production (EGP).Research design and methodsWe performed a randomized, placebo-controlled, crossover study in 28 healthy men and women to determine the effect of PA (1500 mg calcium propionate) on these factors. Subjects had two study visits, each preceded by a 1 week, PA-free diet. During each visit, glucose, insulin, glucagon, norepinephrine, epinephrine, and EGP were assessed for 2 hours after oral administration of PA/placebo under resting conditions (protocol 1) and during either a euglycemic (~85–90 mg/dL) or hypoglycemic (~65–70 mg/dL) hyperinsulinemic clamp (protocol 2).ResultsPA, as compared with placebo, significantly increased: (1) glucagon and norepinephrine during protocol 1; (2) glucagon, norepinephrine, and epinephrine under euglycemic conditions in protocol 2; and (3) norepinephrine, epinephrine, and EGP under hypoglycemic conditions in protocol 2.ConclusionOral consumption of PA leads to inappropriate activation of the insulin counterregulatory hormonal network. This inappropriate stimulation highlights PA as a potential metabolic disruptor.

2002 ◽  
Vol 282 (6) ◽  
pp. E1360-E1368 ◽  
Author(s):  
Thongchai Pratipanawatr ◽  
Wilailak Pratipanawatr ◽  
Clifford Rosen ◽  
Rachele Berria ◽  
Mandeep Bajaj ◽  
...  

The effects of insulin-like growth factor I (IGF-I) and insulin on free fatty acid (FFA) and glucose metabolism were compared in eight control and eight type 2 diabetic subjects, who received a two-step euglycemic hyperinsulinemic (0.25 and 0.5 mU · kg−1 · min−1) clamp and a two-step euglycemic IGF-I (26 and 52 pmol · kg−1 · min−1) clamp with [3-3H]glucose, [1-14C]palmitate, and indirect calorimetry. The insulin and IGF-I infusion rates were chosen to augment glucose disposal (Rd) to a similar extent in control subjects. In type 2 diabetic subjects, stimulation of Rd (second clamp step) in response to both insulin and IGF-I was reduced by ∼40–50% compared with control subjects. In control subjects, insulin was more effective than IGF-I in suppressing endogenous glucose production (EGP) during both clamp steps. In type 2 diabetic subjects, insulin-mediated suppression of EGP was impaired, whereas EGP suppression by IGF-I was similar to that of controls. In both control and diabetic subjects, IGF-I-mediated suppression of plasma FFA concentration and inhibition of FFA turnover were markedly impaired compared with insulin ( P < 0.01–0.001). During the second IGF-I clamp step, suppression of plasma FFA concentration and FFA turnover was impaired in diabetic vs. control subjects ( P < 0.05–0.01). Conclusions: 1) IGF-I is less effective than insulin in suppressing EGP and FFA turnover; 2) insulin-resistant type 2 diabetic subjects also exhibit IGF-I resistance in skeletal muscle. However, suppression of EGP by IGF-I is not impaired in diabetic individuals, indicating normal hepatic sensitivity to IGF-I.


2009 ◽  
Vol 201 (3) ◽  
pp. 377-386 ◽  
Author(s):  
Lars P Klieverik ◽  
Ewout Foppen ◽  
Mariëtte T Ackermans ◽  
Mireille J Serlie ◽  
Hans P Sauerwein ◽  
...  

Thyronamines are naturally occurring, chemical relatives of thyroid hormone. Systemic administration of synthetic 3-iodothyronamine (T1AM) and – to a lesser extent – thyronamine (T0AM), leads to acute bradycardia, hypothermia, decreased metabolic rate, and hyperglycemia. This profile led us to hypothesize that the central nervous system is among the principal targets of thyronamines. We investigated whether a low dose i.c.v. infusion of synthetic thyronamines recapitulates the changes in glucose metabolism that occur following i.p. thyronamine administration. Plasma glucose, glucoregulatory hormones, and endogenous glucose production (EGP) using stable isotope dilution were monitored in rats before and 120 min after an i.p. (50 mg/kg) or i.c.v. (0.5 mg/kg) bolus infusion of T1AM, T0AM, or vehicle. To identify the peripheral effects of centrally administered thyronamines, drug-naive rats were also infused intravenously with low dose (0.5 mg/kg) thyronamines. Systemic T1AM rapidly increased EGP and plasma glucose, increased plasma glucagon, and corticosterone, but failed to change plasma insulin. Compared with i.p.-administered T1AM, a 100-fold lower dose administered centrally induced a more pronounced acute EGP increase and hyperglucagonemia while plasma insulin tended to decrease. Both systemic and central infusions of T0AM caused smaller increases in EGP, plasma glucose, and glucagon compared with T1AM. Neither T1AM nor T0AM influenced any of these parameters upon low dose i.v. administration. We conclude that central administration of low-dose thyronamines suffices to induce the acute alterations in glucoregulatory hormones and glucose metabolism following systemic thyronamine infusion. Our data indicate that thyronamines can act centrally to modulate glucose metabolism.


2004 ◽  
Vol 287 (1) ◽  
pp. E63-E68 ◽  
Author(s):  
M. M. Buijs ◽  
J. A. Romijn ◽  
J. Burggraaf ◽  
M. L. de Kam ◽  
M. Frölich ◽  
...  

It has been suggested that (abdominally) obese individuals are hypersensitive to growth hormone (GH) action. Because GH affects glucose metabolism, this may impact glucose homeostasis in abdominal obesity. Therefore, we studied the effect of GH on glucose metabolism in abdominally obese (OB) and normal-weight (NW) premenopausal women. A 1-h intravenous infusion of GH or placebo was randomly administered to six NW [body mass index (BMI) 21.1 ± 1.9 kg/m2] and six OB (BMI 35.5 ± 1.5 kg/m2) women in a crossover design. Insulin, glucagon, and GH secretion were suppressed by concomitant infusion of somatostatin. Glucose kinetics were measured using a 10-h infusion of [6,6-2H2]glucose. In both groups, similar physiological GH peaks were reached by infusion of GH. GH strongly stimulated endogenous glucose production (EGP) in both groups. The percent increase was significantly greater in OB than in NW women (29.8 ± 11.3 vs. 13.3 ± 7.4%, P = 0.014). Accordingly, GH responsiveness, defined as the maximum response of EGP per unit GH, was increased in OB vs. NW subjects (6.0 ± 2.1 vs. 2.2 ± 1.5 μmol·min−1·mU−1·l−1, P = 0.006). These results suggest that the liver is hyperresponsive to GH action in abdominally obese women. The role of the somatotropic ensemble in the control of glucose homeostasis in abdominal obesity is discussed.


1985 ◽  
Vol 54 (2) ◽  
pp. 459-471 ◽  
Author(s):  
A. N. Janes ◽  
T. E. C. Weekes ◽  
D. G. Armstrong

1. The effect of an exogenous supply of glucose, provided by the digestion of maize starch in the small intestine, on endogenous glucose metabolism and insulin action was studied in sheep using the euglycaemic insulin clamp procedure.2. Insulin was infused intravenously at rates of 0.2, 0.5, 1.0 and 6.0 mU/min per kg live weight for four consecutive periods in each of four sheep fed on dried-grass and maize-based diets. Glucose was also infused intravenously at a variable rate, sufficient to maintain the plasma glucose concentration at basal levels. Whole-body rates of glucose metabolism were determined using a continuous infusion of [6-3H]glucose.3. From the resultinginsulin dose-response curves, it was observed that, when the sheep were fed on the dried-grass diet, the responsiveness of glucose metabolism to insulin was less than that reported for non-ruminants.4. When fed the maize-based diet, the glucose metabolic clearance rates (MCR) observed during insulin infusions were significantly greater (P < 0.05) than those observed for the dried-grass diet. However, after correcting for the non-insulin-mediated glucose disposal, differences between diets were not significant.5. The sensitivity of glucose utilization to insulin was not affected by diet. The plasma insulin concentrations causing half-maximal insulin-mediated glucose MCR were 103 (SE 21) and 85 (SE 11) mU/l for the dried-grass and maize-based diets respectively.6. The sensitivity of endogenous glucose production to insulin was also unaffected by diet. The plasma insulin concentrations resulting in the suppression of endogenous glucose production to half the basal level were 80 (SE 26) and 89 (SE 29) mU/l for the dried-grass and maize-based diets respectively.7. It is concluded that the observed increase in glucose utilization on the maize-based diet was due partly to a slight change in responsiveness to insulin and also partly to a change in the rate of non-insulin-mediated glucose disposal.


2003 ◽  
pp. 511-519 ◽  
Author(s):  
M Segerlantz ◽  
M Bramnert ◽  
P Manhem ◽  
E Laurila ◽  
LC Groop

OBJECTIVE: Previous studies evaluating the lipolytic effect of GH have in general been performed in subjects on chronic GH therapy. In this study we assessed the lipolytic effect of GH in previously untreated patients and examined whether the negative effect of enhanced lipolysis on glucose metabolism could be counteracted by acute antilipolysis achieved with acipimox. METHODS: Ten GH-deficient (GHD) adults participated in four experiments each, during which they received in a double-blind manner: placebo (A); GH (0.88+/-0.13 mg) (B); GH+acipimox 250 mg b.i.d. (C); and acipimox b.i.d. (no GH) (D), where GH was given the night before a 2 h euglycemic, hyperinsulinemic clamp combined with infusion of [3-(3)H]glucose and indirect calorimetry. RESULTS: GH increased basal free fatty acid (FFA) levels by 74% (P=0.0051) and insulin levels by 93% (P=0.0051). This resulted in a non-significant decrease in insulin-stimulated glucose uptakes (16.61+/-8.03 vs 12.74+/-5.50 micromol/kg per min (s.d.), P=0.07 for A vs B). The rates of insulin-stimulated glucose uptake correlated negatively with the FFA concentrations (r=-0.638, P<0.0001). However, acipimox caused a significant improvement in insulin-stimulated glucose uptake in the GH-treated patients (17.35+/-5.65 vs 12.74+/-5.50 micromol/kg per min, P=0.012 for C vs B). The acipimox-induced enhancement of insulin-stimulated glucose uptake was mainly due to an enhanced rate of glucose oxidation (8.32+/-3.00 vs 5.88+/-2.39 micromol/kg per min, P=0.07 for C vs B). The enhanced rates of glucose oxidation induced by acipimox correlated negatively with the rate of lipid oxidation in GH-treated subjects both in basal (r=-0.867, P=0.0093) and during insulin-stimulated (r=-0.927, P=0.0054) conditions. GH did not significantly impair non-oxidative glucose metabolism (6.86+/-5.22 vs 8.67+/-6.65 micromol/kg per min, P=NS for B vs A). The fasting rate of endogenous glucose production was unaffected by GH and acipimox administration (10.99+/-1.98 vs 11.73+/-2.38 micromol/kg per min, P=NS for B vs A and 11.55+/-2.7 vs 10.99+/-1.98 micromol/kg per min, P=NS for C vs B). On the other hand, acipimox alone improved glucose uptake in the untreated GHD patients (24.14+/-8.74 vs 16.61+/-8.03 micromol/kg per min, P=0.0077 for D vs A) and this was again due to enhanced fasting (7.90+/-2.68 vs 5.16+/-2.28 micromol/kg per min, P=0.01 for D vs A) and insulin-stimulated (9.78+/-3.68 vs 7.95+/-2.64 micromol/kg per min, P=0.07 for D vs A) glucose oxidation. CONCLUSION: The study of acute administration of GH to previously untreated GHD patients provides compelling evidence that (i) GH-induced insulin resistance is mainly due to induction of lipolysis by GH; and (ii) inhibition of lipolysis can prevent the deterioration of insulin sensitivity. The question remains whether GH replacement therapy should, at least at the beginning of therapy, be combined with means to prevent an excessive stimulation of lipolysis by GH.


1999 ◽  
Vol 276 (1) ◽  
pp. E78-E84 ◽  
Author(s):  
Eugenio Cersosimo ◽  
Peter Garlick ◽  
John Ferretti

Eighteen healthy subjects had arterialized hand and renal veins catheterized after an overnight fast. Systemic and renal glucose and glycerol kinetics were measured with [6,6-2H2]glucose and [2-13C]glycerol before and after 180-min peripheral infusions of insulin at 0.125 (LO) or 0.25 (HI) mU ⋅ kg−1 ⋅ min−1with variable [6,6-2H2]dextrose or saline (control). Renal plasma flow was determined by plasma p-aminohippurate clearance. Arterial insulin increased from 37 ± 8 to 53 ± 5 (LO) and to 102 ± 10 pM (HI, P < 0.01) but not in control (35 ± 8 pM). Arterial glucose did not change and averaged 5.2 ± 0.1 (control), 4.7 ± 0.2 (LO), and 5.1 ± 0.2 (HI) μmol/ml; renal vein glucose decreased from 4.8 ± 0.2 to 4.5 ± 0.2 μmol/ml (LO) and from 5.3 ± 0.2 to 4.9 ± 0.1 μmol/ml (HI) with insulin but not saline infusion (5.3 ± 0.1 μmol/ml). Endogenous glucose production decreased from 9.9 ± 0.7 to 6.9 ± 0.5 (LO) and to 5.7 ± 0.5 (HI) μmol ⋅ kg−1 ⋅ min−1; renal glucose production decreased from 2.5 ± 0.6 to 1.5 ± 0.5 (LO) and to 1.2 ± 0.6 (HI) μmol ⋅ kg−1 ⋅ min−1, whereas renal glucose utilization increased from 1.5 ± 0.6 to 2.6 ± 0.7 (LO) and to 2.9 ± 0.7 (HI) μmol ⋅ kg−1 ⋅ min−1after insulin infusion (all P < 0.05 vs. baseline). Neither endogenous glucose production (10.0 ± 0.4), renal glucose production (1.1 ± 0.4), nor renal glucose utilization (0.8 ± 0.4) changed in the control group. During insulin infusion, systemic gluconeogenesis from glycerol decreased from 0.67 ± 0.05 to 0.18 ± 0.02 (LO) and from 0.60 ± 0.04 to 0.20 ± 0.02 (HI) μmol ⋅ kg−1 ⋅ min−1( P < 0.01), and renal gluconeogenesis from glycerol decreased from 0.10 ± 0.02 to 0.02 ± 0.02 (LO) and from 0.15 ± 0.03 to 0.09 ± 0.03 (HI) μmol ⋅ kg−1 ⋅ min−1( P < 0.05). In contrast, during saline infusion, systemic (0.66 ± 0.03 vs. 0.82 ± 0.05 μmol ⋅ kg−1 ⋅ min−1) and renal gluconeogenesis from glycerol (0.11 ± 0.02 vs. 0.41 ± 0.04 μmol ⋅ kg−1 ⋅ min−1) increased ( P < 0.05 vs. baseline). We conclude that glucose production and utilization by the kidney are important insulin-responsive components of glucose metabolism in humans.


1989 ◽  
Vol 257 (2) ◽  
pp. R350-R357 ◽  
Author(s):  
J. A. Owens ◽  
J. Falconer ◽  
J. S. Robinson

The effect of restricting placental growth on glucose metabolism in pregnant sheep in late gestation was determined by primed constant infusions of D-[U-14C]- and D-[2-3H]glucose and antipyrine into fetuses of six control sheep and six sheep from which endometrial caruncles had been removed before pregnancy (caruncle sheep). In the latter, placental and fetal weights were reduced, as was the concentration of glucose in fetal arterial blood. Fetal glucose turnover in caruncle sheep was only 52-59% of that in controls, largely because of lower umbilical loss of glucose back to the placenta (38-39% of control) and lower fetal glucose utilization (61-74% of control). However, fetal glucose utilization on a weight-specific basis was similar in control and caruncle sheep. Significant endogenous glucose production occurred in control and caruncle fetal sheep. Maternal glucose production and partition of glucose between the gravid uterus and other maternal tissues were similar in control and caruncle sheep. In conclusion, when placental and fetal growth are restricted, fetal glucose utilization is maintained by reduced loss of glucose back to the placenta and mother and by maintaining endogenous glucose production.


2001 ◽  
Vol 86 (1) ◽  
pp. 3-11 ◽  
Author(s):  
Sylvie Normand ◽  
Yadh Khalfallah ◽  
Corinne Louche-Pelissier ◽  
Christiane Pachiaudi ◽  
Jean-Michel Antoine ◽  
...  

The present study evaluates the influence of different amounts of fat added to starch on postprandial glucose metabolism (exogenous and endogenous). Nine women (24 (SE 2) YEARS OLD, BMI 20·4 (se 0·7) kg/m2) ingested 1 week apart 75 g glucose equivalent of 13C-labelled starch in the form of pasta without (low fat; LF) or with 15 (medium fat; MF) or 40 (high fat; HF) g sunflower oil. During the 7 h following meal consumption, plasma glucose, non-esterified fatty acids, triacylglycerols (TG) and insulin concentrations, and endogenous (using [6,6-2H2]glucose) and exogenous glucose turnover were determined. With MF and HF meals, a lower postprandial glucose peak was observed, but with a secondary recovery. A decrease in exogenous glucose appearance explained lower glycaemia in HF. At 4 h after the HF meal the insulin, insulin:glucose and postprandial blood TG were higher than those measured after the LF and MF meals. Despite higher insulinaemia, total glucose disappearance was similar and endogenous glucose production was suppressed less than after the LF and MF meals, suggesting insulin resistance. Thus, the addition of a large amount of fat appears to be unfavourable to glucose metabolism because it leads to a feature of insulin resistance. On the contrary, the MF meal did not have these adverse effects, but it was able to decrease the initial glycaemic peak.


2012 ◽  
Vol 303 (12) ◽  
pp. E1397-E1407 ◽  
Author(s):  
Maarten R. Soeters ◽  
Peter B. Soeters ◽  
Marieke G. Schooneman ◽  
Sander M. Houten ◽  
Johannes A. Romijn

The human organism has tools to cope with metabolic challenges like starvation that are crucial for survival. Lipolysis, lipid oxidation, ketone body synthesis, tailored endogenous glucose production and uptake, and decreased glucose oxidation serve to protect against excessive erosion of protein mass, which is the predominant supplier of carbon chains for synthesis of newly formed glucose. The starvation response shows that the adaptation to energy deficit is very effective and coordinated with different adaptations in different organs. From an evolutionary perspective, this lipid-induced effect on glucose oxidation and uptake is very strong and may therefore help to understand why insulin resistance in obesity and type 2 diabetes mellitus is difficult to treat. The importance of reciprocity in lipid and glucose metabolism during human starvation should be taken into account when studying lipid and glucose metabolism in general and in pathophysiological conditions in particular.


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