scholarly journals Prevention of Hyperglycemia

2021 ◽  
Author(s):  
Lucy A. Ochola ◽  
Eric M. Guantai

Hyperglycemia is the elevation of blood glucose concentrations above the normal range. Prolonged uncontrolled hyperglycemia is associated with serious life-threatening complications. Hyperglycemia arises from an imbalance between glucose production and glucose uptake and utilization by peripheral tissues. Disorders that compromise pancreatic function or affect the glucose counter-regulatory hormones cause hyperglycemia. Acute or serious illness or injury may also bring about hyperglycemia, as can many classes of drugs. Metformin lowers blood glucose levels by inhibiting the production of glucose by the liver whilst enhancing uptake of circulating glucose and its utilization in peripheral tissues such as muscle and adipose tissue. Metformin suppresses hepatic gluconeogenesis by inhibiting mitochondrial respiration and causing a reduction of cellular ATP levels. Metformin may also modulate the gut-brain-liver axis, resulting in suppression of hepatic glucose production. Metformin also opposes the hyperglycemic action of glucagon and may ameliorate pancreatic cell dysfunction associated with hyperglycemia. Metformin is therefore recommended for use in the prevention of hyperglycemia, including drug-induced hyperglycemia, in at risk patients. The benefits of metformin in the prevention of hyperglycemia are unmatched despite its contraindications.

2003 ◽  
Vol 285 (4) ◽  
pp. E718-E728 ◽  
Author(s):  
Jennifer Altomonte ◽  
Anja Richter ◽  
Sonal Harbaran ◽  
Jenny Suriawinata ◽  
Jun Nakae ◽  
...  

Excessive hepatic glucose production is a contributing factor to fasting hyperglycemia in diabetes. Insulin suppresses hepatic glucose production by inhibiting the expression of two gluconeogenic enzymes, phospho enolpyruvate carboxykinase (PEPCK) and glucose-6-phosphatase (G-6-Pase). The forkhead transcription factor Foxo1 has been implicated as a mediator of insulin action in regulating hepatic gluconeogenesis, and a Foxo1 mutant (Foxo1-Δ256), devoid of its carboxyl domain, has been shown to interfere with Foxo1 function and inhibit gluconeogenic gene expression in cultured cells. To study the effect of Foxo1-Δ256 on glucose metabolism in animals, the Foxo1-Δ256 cDNA was delivered to the livers of mice by adenovirus-mediated gene transfer. Hepatic Foxo1-Δ256 production resulted in inhibition of gluconeogenic activity, as evidenced by reduced PEPCK and G-6-Pase expression in the liver. Mice treated with the Foxo1-Δ256 vector exhibited significantly reduced blood glucose levels. In contrast, blood glucose levels in control vector-treated animals remained unchanged, which coincided with the lack of alterations in the expression levels of PEPCK and G-6-Pase. When tested in diabetic db/db mice, hepatic production of Foxo1-Δ256 was shown to reduce fasting hyperglycemia. Furthermore, we showed that hepatic Foxo1 expression was deregulated as a result of insulin resistance in diabetic mice and that Foxo1-Δ256 interfered with Foxo1 function via competitive binding to target promoters. These results demonstrated that functional inhibition of Foxo1, caused by hepatic expression of its mutant, is associated with reduced hepatic gluconeogenic activity and improved fasting glycemia in diabetic mice.


2019 ◽  
Vol 20 (15) ◽  
pp. 3699 ◽  
Author(s):  
Norikiyo Honzawa ◽  
Kei Fujimoto ◽  
Tadahiro Kitamura

To date, type 2 diabetes is considered to be a “bi-hormonal disorder” rather than an “insulin-centric disorder,” suggesting that glucagon is as important as insulin. Although glucagon increases hepatic glucose production and blood glucose levels, paradoxical glucagon hypersecretion is observed in diabetes. Recently, insulin resistance in pancreatic α cells has been proposed to be associated with glucagon dysregulation. Moreover, cell autonomous dysfunction of α cells is involved in the etiology of diabetes. In this review, we summarize the current knowledge about the physiological and pathological roles of glucagon.


2020 ◽  
Vol 2020 ◽  
pp. 1-8 ◽  
Author(s):  
Ying Zhong ◽  
Jing Jin ◽  
Peiyu Liu ◽  
Yu Song ◽  
Hui Zhang ◽  
...  

Dysregulated glucagon drives hyperfunction in hepatic glucose output, which is the main cause of persistent hyperglycemia in type 2 diabetes. Berberine (Zhang et al., 2010) has been used as a hypoglycemic agent, yet the mechanism by which BBR inhibits hepatic gluconeogenesis remains incompletely understood. In this study, we treated diabetic mice with BBR, tested blood glucose levels, and then performed insulin, glucose lactate, and glucagon tolerance tests. Intracellular cAMP levels in hepatocytes were determined by ELISA, hepatic gluconeogenetic genes were assayed by RT-qPCR, and the phosphorylation of CREB, which is the transcriptional factor controlling the expression of gluconeogenetic genes, was detected by western blot. BBR reduced blood glucose levels, improved insulin and glucose tolerance, and suppressed lactate- and glucagon-induced hepatic gluconeogenesis in ob/ob and STZ-induced diabetic mice. Importantly, BBR blunted glucagon-induced glucose production and gluconeogenic gene expression in hepatocytes, presumably through reducing cAMP, which resulted in the phosphorylation of CREB. By utilizing a cAMP analogue, adenylate cyclase (AC), to activate cAMP synthetase, and an inhibitor of the cAMP degradative enzyme, phosphodiesterase (PDE), we revealed that BBR accelerates intracellular cAMP degradation. BBR reduces the intracellular cAMP level by activating PDE, thus blocking activation of downstream CREB and eventually downregulating gluconeogenic genes to restrain hepatic glucose production.


1998 ◽  
Vol 274 (1) ◽  
pp. E162-E171 ◽  
Author(s):  
Chang An Chu ◽  
Dana K. Sindelar ◽  
Doss W. Neal ◽  
Eric J. Allen ◽  
E. Patrick Donahue ◽  
...  

To determine the effect of a selective rise in liver sinusoidal norepinephrine (NE) on hepatic glucose production (HGP), norepinephrine (50 ng ⋅ kg−1 ⋅ min−1) was infused intraportally (Po-NE) for 3 h into five 18-h-fasted conscious dogs with a pancreatic clamp. In the control protocol, NE (0.2 ng ⋅ kg−1 ⋅ min−1) and glucose were infused peripherally to match the arterial NE and blood glucose levels in the Po-NE group. Hepatic sinusoidal NE levels rose ∼30-fold in the Po-NE group but did not change in the control group. The arterial NE levels did not change significantly in either group. During the portal NE infusion, HGP increased from 1.9 ± 0.2 to 3.5 ± 0.4 mg ⋅ kg−1 ⋅ min−1(15 min; P < 0.05) and then gradually fell to 2.4 ± 0.4 mg ⋅ kg−1 ⋅ min−1by 3 h. HGP in the control group did not change (2.0 ± 0.2 to 2.0 ± 0.2 mg ⋅ kg−1 ⋅ min−1) for 15 min but then gradually fell to 1.1 ± 0.2 mg ⋅ kg−1 ⋅ min−1by the end of the study. Because the fall in HGP from 15 min on was parallel in the two groups, the effect of NE on HGP (the difference between HGP in the two groups) did not decline over time. Gluconeogenesis did not change significantly in either group. In conclusion, elevation in hepatic sinusoidal NE significantly increases HGP by selectively stimulating glycogenolysis. Compared with the previously determined effects of epinephrine or glucagon on HGP, the effect of NE is, on a molar basis, less potent but nore sustained over time.


2019 ◽  
Vol 7 (8) ◽  
pp. e14043 ◽  
Author(s):  
Dharendra Thapa ◽  
Bingxian Xie ◽  
Janet R. Manning ◽  
Manling Zhang ◽  
Michael W. Stoner ◽  
...  

1990 ◽  
Vol 258 (3) ◽  
pp. R770-R776 ◽  
Author(s):  
C. M. Donovan ◽  
K. D. Sumida

The effects of endurance training (running 1 h/day at 35 m/min, 10% grade) on glucose homeostasis during exercise (running 20 m/min) was studied in 30-h fasted rats. Primed-continuous infusion of [6-3H]- and [U-14C]glucose were employed to assess rates of appearance (Ra), disappearance (Rd), and apparent recycling. Training resulted in a 65% increase in skeletal muscle succinate dehydrogenase (SDH) activity but did not significantly influence body weight. Resting blood glucose concentrations were not significantly different between controls, 5.01 +/- 0.19 mM, and trained animals, 4.86 +/- 0.16 mM. Exercise resulted in a more rapid decline in blood glucose levels for control animals, reaching a value of 2.35 +/- 0.39 mM at 60 min, compared with 3.69 +/- 0.47 mM for trained animals. Glucose Ra was not significantly different between groups at rest, and rose for both groups during exercise. However, for controls Ra plateaued between 15 and 60 min of exercise at 11.03 +/- 0.73 mumol.100 g-1.min-1, whereas trained animals demonstrated a continuous rise to 17.13 +/- 1.18 mumol.100 g-1.min-1. Glucose Rd values were not significantly different between groups during the first 30 min of exercise but were significantly higher for trained animals during the final 30 min. As a result of the higher glucose Ra, trained animals demonstrated a smaller mean difference between Ra and Rd during exercise when compared with controls, -0.27 +/- 0.14 vs. -0.96 +/- 0.17 mumol.100 g-1.min-1. Trained animals further demonstrated significantly higher rates of glucose carbon recycling during the final 30 min of exercise.(ABSTRACT TRUNCATED AT 250 WORDS)


2008 ◽  
Vol 295 (4) ◽  
pp. E751-E761 ◽  
Author(s):  
Pritpal Bansal ◽  
Qinghua Wang

Glucose homeostasis is regulated primarily by the opposing actions of insulin and glucagon, hormones that are secreted by pancreatic islets from β-cells and α-cells, respectively. Insulin secretion is increased in response to elevated blood glucose to maintain normoglycemia by stimulating glucose transport in muscle and adipocytes and reducing glucose production by inhibiting gluconeogenesis in the liver. Whereas glucagon secretion is suppressed by hyperglycemia, it is stimulated during hypoglycemia, promoting hepatic glucose production and ultimately raising blood glucose levels. Diabetic hyperglycemia occurs as the result of insufficient insulin secretion from the β-cells and/or lack of insulin action due to peripheral insulin resistance. Remarkably, excessive secretion of glucagon from the α-cells is also a major contributor to the development of diabetic hyperglycemia. Insulin is a physiological suppressor of glucagon secretion; however, at the cellular and molecular levels, how intraislet insulin exerts its suppressive effect on the α-cells is not very clear. Although the inhibitory effect of insulin on glucagon gene expression is an important means to regulate glucagon secretion, recent studies suggest that the underlying mechanisms of the intraislet insulin on suppression of glucagon secretion involve the modulation of KATP channel activity and the activation of the GABA-GABAA receptor system. Nevertheless, regulation of glucagon secretion is multifactorial and yet to be fully understood.


2017 ◽  
Vol 123 (2) ◽  
pp. 278-284 ◽  
Author(s):  
Yoichi Hatamoto ◽  
Ryoma Goya ◽  
Yosuke Yamada ◽  
Eichi Yoshimura ◽  
Sena Nishimura ◽  
...  

There is no consensus regarding optimal exercise timing for reducing postprandial glucose (PPG). The purpose of the present study was to determine the most effective exercise timing. Eleven participants completed four different exercise patterns 1) no exercise; 2) preprandial exercise (jogging); 3) postprandial exercise; and 4) brief periodic exercise intervention (three sets of 1-min jogging + 30 s of rest, every 30 min, 20 times total) in a random order separated by a minimum of 5 days. Preprandial and postprandial exercise consisted of 20 sets of intermittent exercise (1 min of jogging + 30 s rest per set) repeated 3 times per day. Total daily exercise volume was identical for all three exercise patterns. Exercise intensities were 62.4 ± 12.9% V̇o2peak. Blood glucose concentrations were measured continuously throughout each trial for 24 h. After breakfast, peak blood glucose concentrations were lower with brief periodic exercise (99 ± 6 mg/dl) than those with preprandial and postprandial exercise (109 ± 10 and 115 ± 14 mg/dl, respectively, P < 0.05, effect size = 0.517). After lunch, peak glucose concentrations were lower with brief periodic exercise than those with postprandial exercise (97 ± 5 and 108 ± 8 mg/dl, P < 0.05, effect size = 0.484). After dinner, peak glucose concentrations did not significantly differ among exercise patterns. Areas under the curve over 24 h and 2 h postprandially did not differ among exercise patterns. These findings suggest that brief periodic exercise may be more effective than preprandial and postprandial exercise at attenuating PPG in young active individuals. NEW & NOTEWORTHY This was the first study to investigate the effect of different exercise timing (brief periodic vs. preprandial vs. postprandial exercise) on postprandial glucose (PPG) attenuation in active healthy men. We demonstrated that brief periodic exercise attenuated peak PPG levels more than preprandial and postprandial exercise, particularly in the morning. Additionally, PPG rebounded soon after discontinuing postprandial exercise. Thus, brief periodic exercise may be better than preprandial and postprandial exercise at attenuating PPG levels.


2014 ◽  
Vol 29 (1) ◽  
pp. 27-31 ◽  
Author(s):  
Derrick Brown ◽  
Matthew Wyon

Ingesting quality carbohydrates has been shown to be essential for dancers. Given that most dance classes take place in the morning, it has been recommended that dancers eat a well-balanced breakfast containing carbohydrates, fats, and protein as a means of fueling this activity. The aim of this study was to determine the effect of a moderate glycemic index energy (MGI) bar or a fasting condition on dancers’ blood glucose levels and perceived pleasure-displeasure response during the first dance class of the day. In a randomized counterbalanced design, 10 female preprofessional dance students took their regular scheduled contemporary dance class, on four separate occasions. On each occasion, they consumed either a commercially prepared carbohydrate (CHO)-dense energy bar (47.3 g CHO) or water (FAST). Plasma glucose responses and pleasure-displeasure affect were measured before and at two time points during the class. Dancers who consumed the MGI bar had significantly greater peak blood glucose levels at all time points than those who fasted (p<0.05). Regarding affective state measures, participants who had breakfast had significantly greater pleasure scores than those who only ingested water (p<0.05). In conclusion, results suggest that CHO with an MGI value positively impacts blood glucose concentrations during a dance class. Further, we conclude that skipping breakfast can have an unfavorable effect on the pleasure-displeasure state of dancers. These findings highlight the impact of breakfast on how one feels, as well as the physiological and metabolic benefits of CHO as an exogenous energy source in dancers.


Endocrinology ◽  
2015 ◽  
Vol 157 (2) ◽  
pp. 463-469 ◽  
Author(s):  
Hitoshi Ando ◽  
Kentaro Ushijima ◽  
Shigeki Shimba ◽  
Akio Fujimura

Abstract Fasting blood glucose (FBG) and hepatic glucose production are regulated according to a circadian rhythm. An early morning increase in FBG levels, which is pronounced among diabetic patients, is known as the dawn phenomenon. Although the intracellular circadian clock generates various molecular rhythms, whether the hepatic clock is involved in FBG rhythm remains unclear. To address this issue, we investigated the effects of phase shift and disruption of the hepatic clock on the FBG rhythm. In both C57BL/6J and diabetic ob/ob mice, FBG exhibited significant daily rhythms with a peak at the beginning of the dark phase. Light-phase restricted feeding altered the phase of FBG rhythm mildly in C57BL/6J mice and greatly in ob/ob mice, in concert with the phase shifts of mRNA expression rhythms of the clock and glucose production–related genes in the liver. Moreover, the rhythmicity of FBG and Glut2 expression was not detected in liver-specific Bmal1-deficient mice. Furthermore, treatment with octreotide suppressed the plasma growth hormone concentration but did not affect the hepatic mRNA expression of the clock genes or the rise in FBG during the latter half of the resting phase in C57BL/6J mice. These results suggest that the hepatic circadian clock plays a critical role in regulating the daily FBG rhythm, including the dawn phenomenon.


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