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Results for “Glycemic levels”

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PubMed1999

Epidemiology of Diabetes Interventions and Complications (EDIC). Design, implementation, and preliminary results of a long-term follow-up of the Diabetes Control and Complications Trial cohort.

OBJECTIVE: The Diabetes Control and Complications Trial (DCCT) demonstrated the powerful impact of glycemic control on the early manifestations of microvascular complications. Contemporary prospective data on the evolution of macrovascular and late microvascular complications of type 1 diabetes are limited. The Epidemiology of Diabetes Interventions and Complications (EDIC) study is a multicenter, longitudinal, observational study designed to use the well-characterized DCCT cohort of > 1,400 patients to determine the long-term effects of prior separation of glycemic levels on micro- and macrovascular outcomes. RESEARCH DESIGN AND METHODS: Using a standardized annual history and physical examination, 28 EDIC clinical centers that were DCCT clinics will follow the EDIC cohort for 10 years. Annual evaluation also includes resting electrocardiogram. Doppler ultrasound measurements of ankle/arm blood pressure, and screening for nephropathy. At regular intervals, a timed 4-h urine is collected, lipid profiles are obtained, and stereoscopic fundus photographs are taken. In addition, dual B-mode Doppler ultrasound scans of the common and internal carotid arteries will be performed at years 1 and 6 and at study end. RESULTS: Written informed consent was obtained from 96% of the DCCT subjects. The participants, compared with nonparticipants, tended to have better glycemic control at the completion of the DCCT and were more likely to have their diabetes care provided by DCCT personnel. The EDIC baseline measurement stratified by sex delineates multiple cardiovascular disease risk factor differences such as age (older in men), waist-to-hip ratio (higher in men). HDL cholesterol (lower in men), hypertension (more prevalent in men), and maximum intimal-medial thickness of common and internal carotid arteries (thicker in men). Of the original conventional treatment group, 69% have changed to continuous subcutaneous insulin infusion or multiple daily injections. Although the mean HbA1c difference between the intensive and conventional treatment groups narrowed at EDIC years 1 and 2, HbA1c remained significantly lower in the intensive group. Of all expected clinic visits, 95% were completed, and the quality of EDIC data is very similar to that observed in the DCCT. CONCLUSIONS: Although obvious problems exist in extended follow-up studies of completed clinical trials, these are balanced by the value of continued systematic observation of the DCCT cohort. In contrast to other epidemiologic studies, EDIC will provide 1) definitive data on type 1 as distinct from type 2 diabetes; 2) reliance on prospective rather than on cross-sectional analysis; 3) long-term follow-up in a large population; 4) consistent use of objective, reliable measures of outcomes and glycemia; and 5) observation of patients from before the onset of complications.

Adult↗

PubMed2003

Blink reflex alterations in recently diagnosed diabetic patients.

OBJECTIVE: The aim of the present study was to determine the frequency of blink reflex alterations and to examine the influence of hyperglycemia in inducing the alterations in recently diagnosed Type 2 diabetes mellitus patients. METHODS: A cross-sectional study was carried out on patients having asymptomatic diabetes with a period of evolution under 10 years. In all 47 patients (26 women and 21 men), serum glycemia levels were determined and the latency onset of the blink reflex components were measured. RESULTS: The average patient age was 44.5+/-11.0 (mean+/-SD) years with a diabetes evolution period of 4.3+/-2.9 (mean+/-SD) years. After a fasting serum glucose test, the diabetic patients were catalogued as normoglycemic (< or =126 mg/dl) or as hyperglycemic (> 26 mg/dl) and subjected to a blink reflex test. The results obtained from the diabetic patients were compared with those from a non-diabetic control group. 14.8-31.9% of the diabetic patients showed alterations in blink reflex component latencies. The differences compared with the control group were significant (p<0.05). CONCLUSIONS: Diabetes, as is well-known, can affect the central and peripheral nervous system and there does not appear to be a link between glycemic levels and blink reflex components. However, blink reflex alterations were present even in diabetic patients with a relatively short period of disease evolution.

Blinking↗

PubMed1996

[Remission of severe hypoglycemic incidents in young diabetic children treated with subcutaneous infusion].

BACKGROUND: Conventional insulin therapy for diabetes mellitus can be inadequate for controlling glycemia in young patients in whom the risk of hypoglycemia is particularly high. PATIENTS: A retrospective study comparing all the children under 6 years of age treated in our department by continuous subcutaneous insulin infusion (group P, n = 10, mean age: 3.7 years) to 17 children with conventional insulin therapy (group C, mean age: 5.1 years) was conducted during a mean period of 2 years. RESULTS: Mean insulin doses, HbAlc, pre-prandial and daily glycemic levels, measured at 0, 3, 6, 12, 18 and 24 months, did not differ significantly between both groups. Mean HbAlc levels remained < or = 8% in the two groups. There was no episode of severe hypoglycemia in group P vs ten episodes in group C (P < 0.05); this benefit was confirmed in those six children belonging to group P who had previously followed a conventional therapy: 11 episodes during the conventional period vs 0 episode during the pump period (P < 0.05). Nine out of ten families were very satisfied with the treatment by pump mainly because of a more comfortable life style and a reduction of parents' anxiety due to disappearance of severe hypoglycemias. The insulin pump therapy had some limits: cutaneous complications and technical ones were responsible for two keto-acidosis episodes (0.1 episode per year-patient) and a higher frequency of hospitalizations. In group C, hospitalizations were caused by severe hypoglycemias and unbalanced glycemic control. CONCLUSIONS: Insulin pump therapy could be indicated in young diabetic children at high risk of severe hypoglycemia under conditions of a specialized medical and educational supervision and knowledge of the limits of such a treatment.

Age Factors↗

PubMed2004

Glycemia in newborns of hypertensive mothers according to maternal treatment.

PURPOSE: To evaluate the evolution of glycemic levels in newborns of hypertensive mothers according to maternal treatment. METHODS: Prospective randomized study, including 93 newborns of mothers treated with isradipine (n = 39), atenolol (n = 40), or low sodium diet (control group - n=14). Glycemia was determined at birth (mother and newborn by the oxidase glucose method) and in the 1st, 3rd, 6th, 12th, and 24th hours after birth (newborn by a test strip method). The evolution of glycemia was analyzed in each group (Friedman test). The groups were compared regarding glycemia (Kruskall-Wallis test), and linear regression models were constructed for the analyses (independent variable = maternal glycemia; dependent variables = umbilical cord, 3rd, and 6th hour glycemia). RESULTS: There were no statistically significant differences among the mean blood glucose levels of the 3 groups in any of the assessments. There was a correlation between maternal and umbilical cord blood glucose in the isradipine (r = 0.61; P <.05) and control (r = 0.84; P <.05) groups. Regarding glycemia levels of the mothers and newborns in the third and sixth hours postpartum, this correlation was present only in the control group (maternal x third hour: r = 0.65; P <.05; maternal x sixth hour: r = 0.68; P <.05). There were no correlations in the atenolol group. Hypoglycemia was detected in 51.3% of the isradipine group, 60% of the atenolol group, and 35.7% of the control group, and it was more frequent in the first hour postpartum in all groups. CONCLUSIONS: The results suggest a similar effect of the 3 types of treatment upon newborn glycemia. The correlation analysis suggests that isradipine could have effects upon newborn glycemia only after birth (correlation only in umbilical cord blood), whereas atenolol could act earlier (there was no correlation at any moment). The results also point to the need for glycemic control from the first hour postpartum of newborns of hypertensive mothers whether they have or have not undergone treatment with antihypertensive drugs.

Antihypertensive Agents↗

PubMed1990

Early administration of an immunomodulator and induction of remission in insulin-dependent diabetes mellitus.

A clinical trial was undertaken to determine whether intensive thymopentin administration enhances remission of insulin-dependent diabetes (IDDM) during the first year after diagnosis. Dosage with insulin was minimized with target control of blood glucose levels less than or equal to 7.8 mmol/l before meals. Remission was defined as a prolonged period after IDDM onset (not less than 3 months) characterized by a non-insulin-receiving (NIR) state in which target metabolic control was reached without administration of insulin and with a valid C-peptide response, evaluated after standard breakfast. Sixteen IDDM patients aged 12-31 years, recruited within 2 weeks of initiation of insulin therapy and within 5 weeks of onset of symptoms, were treated with intravenous (i.v.) thymopoietin32-36 pentapeptide (Thy) (1 mg/kg/body weight) for 7 days and twice per week for up to 3 months. A control IDDM group without initial significant differences in metabolic control parameters was also studied. No difference was observed between the two IDDM groups regarding the after-diagnosis normalization curve of HbA1c; mean daily glycemic level rates and ICA titer decreased during the observation. A reduction in anti-insulin antibodies (AIA) in Thy-treated patients was observed in comparison to conventionally treated IDDM starting from 6 months and reaching a reduction peak at 1 year (P less than or equal to 0.02). As regards the NIR remission rate, it was significantly more accelerated in Thy-treated patients, reaching 43% at 6 months and 57% at 1 year vs 12% and 6.7% respectively in the control IDDM group (P range less than or equal to 0.05-0.02).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed2004

The effects of dehydroepiandrosterone sulfate on counterregulatory responses during repeated hypoglycemia in conscious normal rats.

We previously determined that both antecedent hypoglycemia and elevated cortisol levels blunt neuroendocrine and metabolic responses to subsequent hypoglycemia in conscious, unrestrained rats. The adrenal steroid dehydroepiandrosterone sulfate (DHEA-S) has been shown in several studies to oppose corticosteroid action. The purpose of this study was to determine if DHEA-S could preserve counterregulatory responses during repeated hypoglycemia. We studied 40 male Sprague-Dawley rats during a series of 2-day protocols. Day 1 consisted of two 2-h episodes of 1) hyperinsulinemic (30 pmol. kg(-1). min(-1)) euglycemia (6.2 +/- 0.2 mmol/l; n = 12; ANTE EUG), 2) hyperinsulinemic euglycemia (6.0 +/- 0.1 mmol/l; n = 8) plus simultaneous intravenous infusion of DHEA-S (30 mg/kg; ANTE EUG + DHEA-S), 3) hyperinsulinemic hypoglycemia (2.8 +/- 0.1 mmol/l; n = 12; ANTE HYPO), or 4) hyperinsulinemic hypoglycemia (2.8 +/- 0.1 mmol/l; n = 8) with simultaneous intravenous infusion of DHEA-S (30 mg/kg; ANTE HYPO + DHEA-S). Day 2 consisted of a single 2-h hyperinsulinemic hypoglycemic (2.8 +/- 0.1 mmol/l) clamp. During the final 30 min of day 2, hypoglycemia norepinephrine levels were significantly lower in the ANTE HYPO group versus the ANTE HYPO + DHEA-S group (2.0 +/- 0.2 vs. 3.3 +/- 0.6 nmol/l; P < 0.05). In addition, epinephrine (8 +/- 1 vs. 17 +/- 2, 14 +/- 3, and 15 +/- 3 nmol/l), glucagon (91 +/- 8 vs. 273 +/- 36, 231 +/- 42, and 297 +/- 48 ng/l), and corticosterone (1,255 +/- 193 vs. 1,915 +/- 212, 1,557 +/- 112, and 1,668 +/- 119 pmol/l) were significantly lower in the ANTE HYPO group versus the ANTE EUG, ANTE EUG + DHEA-S, and ANTE HYPO + DHEA-S groups (P < 0.05). Endogenous glucose production was also significantly less in the ANTE HYPO group versus the ANTE EUG, ANTE EUG + DHEA-S, and ANTE HYPO + DHEA-S groups (13 +/- 5 vs. 32 +/- 3, 38 +/- 7, and 29 +/- 8 micro mol/l. kg(-1). min(-1); P < 0.05). Consequently, the amount of exogenous glucose needed to maintain the glycemic level during the clamp studies was significantly higher in the ANTE HYPO versus the ANTE EUG, ANTE EUG + DHEA-S, and ANTE HYPO + DHEA-S groups (57 +/- 8 vs. 22 +/- 5, 18 +/- 6, and 18 +/- 3 micro mol/l. kg(-1). min(-1); P < 0.05). In summary, day-1 antecedent hypoglycemia blunted neuroendocrine and metabolic responses to next-day hypoglycemia. However, simultaneous DHEA-S infusion during antecedent hypoglycemia preserved neuroendocrine and metabolic counterregulatory responses during subsequent hypoglycemia in conscious rats.

Animals↗

PubMedDate not supplied

Diet only or diet and sulfonylureas in mild type II diabetes (NIDDM)? Pathophysiologic and therapeutic implications.

UNLABELLED: Plasma glucose, insulin and C-peptide responses to a test meal were studied in 7 nonobese patients with type II diabetes mellitus (NIDDM) treated with diet alone and after 6 months of gliclazide therapy, as well as in 6 matched controls. The glycemic levels were significantly higher (p less than 0.05) in patients under diet alone than in controls and after gliclazide treatment (peak: 12.8 +/- 1.0; 7.9 +/- 0.4 and 10.0 +/- 0.5 mmol/l, respectively; means +/- SEM). Diet and gliclazide treated patients showed a reduced B-cell response during the first hour after the meal as indicated by insulin and C-peptide values and areas (insulin areas 0-60 min: controls 57.9 +/- 10.9; p less than 0.01 vs diet alone 14.2 +/- 2.7 and vs gliclazide 22.1 +/- 2.8 microU/ml/min). The hypoinsulinemic phase lasted from 20 to 60 min before gliclazide, and from 20 to 45 min after gliclazide. The first significant C-peptide increase, detected at 10 min in controls and at 30 min under diet alone, was advanced to 15 min after gliclazide treatment. IN CONCLUSION: patients with mild, diet-treated NIDDM show a sluggish and attenuated B-cell response to a physiologic challenge (test meal); this secretory impairment is present even after a complete post-prandial glycemic normalization, supporting the idea of a persistent defect. Nevertheless, the slight improvement observed in insulin secretion after gliclazide treatment may be promoting, at least partially, the normalization of prandial hyperglycemia. The benefits of this normalization in diabetic patients previously controlled by diet only await further investigation.

Aged↗

PubMed2001

Determinants of the effectiveness of glucagon-like peptide-1 in type 2 diabetes.

GLP-1 lowers blood glucose in fasting type 2 diabetic patients. To clarify the relation of the effect of GLP-1 to obesity, blood glucose, beta-cell function, and insulin sensitivity, GLP-1 (1.2 pmol/kg.min) was infused iv for 4-6 h into 50 fasting type 2 diabetic patients with a wide range of age, body mass index, HbA1c, and fasting plasma glucose. The effectiveness of GLP-1 was evaluated by calculation of a glucose disappearance constant for each individual (Kg, linear slope of log-transformed plasma glucose), and by the lowest stable glucose level (Nadir plasma glucose) obtained during the infusion. Grouped according to fasting plasma glucose (<10, 10-15, >15 mmol/liter), Kg values were 0.45 +/- 0.03, 0.38 +/- 0.04, and 0.28 +/- 0.04%/min (P = 0.005), and Nadir plasma glucose values were 4.7 +/- 0.1 (3.9-5.9), 5.8 +/- 0.4 (4.3-8.4), and 8.7 +/- 1.4 (6.2-18.7) mmol/liter (P = 0.0003). Nonresponders were not identified. Multiple regression analysis with Kg or Nadir plasma glucose as the dependent parameter and body mass index, age, gender, diabetes duration, and significantly correlated parameters (in multiple regression for Kg: fasting plasma glucose, fasting nonesterified fatty acid, dipeptidyl peptidase activity, peak insulin, and the logarithm of beta-cell function; and for Nadir plasma glucose: fasting plasma glucose, fasting nonesterified fatty acid, dipeptidyl peptidase activity, delta glucagon decrement, F-GLP-1 total, logarithm of beta-cell function, and Kg) as independent parameters resulted in fasting plasma glucose as the only significant predictor of Kg, and fasting plasma glucose and Kg as predictors of Nadir plasma glucose. Kg and Nadir plasma glucose were neither influenced by treatment nor by neuropathy per se. In conclusion, GLP-1 lowers plasma glucose in type 2 diabetes regardless of severity, but glucose elimination is faster and obtained glycemic level lower in patients with the lower fasting plasma glucose. Not all patients can be expected to reach normoglycemia.

Area Under Curve↗

PubMed1997

Gallstones and diabetes: a case-control study in a free-living population sample.

Data on the association between cholelithiasis and diabetes often are controversial and are mostly based on autopsies or on hospital series. Therefore, we designed a case-control study to determine the prevalence of diabetes mellitus in a group of subjects with gallstones or having undergone cholecystectomy (cases) and compared these with a control group of subjects without gallstones, selected during an epidemiological study performed on a free-living population sample. The subjects were matched for sex, age, and body mass index. We enlisted 336 cases and 336 controls, aged 30 to 69 years. All subjects with fasting glycemic levels of < 140 mg/dL and without a documented history of diabetes were submitted to a simplified oral glucose tolerance test (OGTT). All subjects who underwent OGTT were classified according to the National Diabetes Data Group (NDDG) criteria. The prevalence of diabetes in the subjects affected by gallstone disease was significantly higher than that in controls (11.6% vs. 4.8%; odds ratio [OR], 2.55; 95% confidence interval [CI], 1.39-4.67). Diabetes was more frequent in subjects with gallstone disease than in the control group, even according to sex (18.3% vs. 9.9% for men: OR, 2.03; 95% CI, 0.99-4.2; 9.3% vs. 2.6% for women: OR, 3.85; 95% CI, 1.4-10.6). We conclude that an altered glucose metabolism may increase the risk of developing cholelithiasis in certain subjects.

Adult↗

PubMed2005

Evaluation of advanced glycation end products and carbonyl compounds in patients with different conditions of oxidative stress.

Advanced glycation end products (AGE) and dicarbonyl compounds accumulate in serum and tissues of patients with diabetes and chronic renal failure. Pentosidine, free pentosidine, glyoxal and methylglyoxal have been evaluated in plasma of diabetic patients with poor metabolic control at baseline and after the improvement of glycemic levels, and in plasma and peritoneal dialysate of patients with renal failure before and after 12 h of peritoneal dialysis. In diabetic patients, acceptable metabolic control was unable to normalize levels of pentosidine (after 2 and 10 months), glyoxal and methylglyoxal (after 2 months). In patients with end-stage renal disease, mean values of pentosidine, free pentosidine, glyoxal and methylglyoxal decreased in plasma after dialysis. No pentosidine or free pentosidine were present in the peritoneal dialysate at time 0, but were found after 12 h of peritoneal dialysis; glyoxal and methylglyoxal decreased after 12 h of dialysis. So, glyoxal and methylglyoxal, already present in the dialysis fluid, can react with the peritoneal matrix protein, giving a reason for the gradual loss of peritoneal membrane function often observed in patients undergoing long-term peritoneal dialysis.

Aged↗

PubMed1994

Sensory thresholds in older adults: reproducibility and reference values.

To evaluate the test-retest reproducibility of vibratory perception (VPT) and thermal discrimination (TDT) thresholds on the foot in older adults, we examined 20 50-76-year-old subjects with, and 19 without non-insulin-dependent diabetes mellitus. Adjusted reference values for both thresholds were obtained by assessing the relations with age, body height, and sex among 216 subjects with normal glucose tolerance, of the same age, sampled randomly from a geographically defined general population. The VPT appeared to be more reproducible than the TDT (reliability coefficient 0.89 vs. 0.54). The reproducibility of the VPT was inversely related to age and better for men than for women. Diabetes and glycemic level did not affect the reproducibility of either threshold. Both thresholds were related to age and height. Women had a higher VPT than men. The relations between sex and sensory thresholds at the lower limb, reported in previous studies, were probably confounded by height.

Age Factors↗

PubMed1996

Phosphotyrosine protein phosphatases and diabetic pregnancy: an association between low molecular weight acid phosphatase and degree of glycemic control.

Low molecular weight acid phosphatase encoded by the highly polymorphic locus ACP1 is a member of the protein-tyrosin phosphatase family (PTPases) which plays an essential role in the control of receptor signalling through phosphotyrosine pathways. Recent experiments have shown that purified rat liver ACP, corresponding to human ACP1, is able to hydrolyze a phosphotyrosine-containing synthetic peptide corresponding to the 1146-1158 sequence of the human insulin receptor, and shows a high affinity for it. This prompted us to analyze the degree of glycemic control in relation to ACP1 genetic variability in a sample of 214 diabetic pregnant women including IDDM, NIDDM and gestational diabetes. The ACP1 genotype was also determined in 482 non-diabetic pregnant women. In diabetic women glycemic levels in the last trimester of pregnancy appear to be significantly associated with the ACP1 genotype, and correlate positively with ACP1 enzymatic activity. The data suggest that quantitative variations of ACP1 may influence the clinical manifestations of diabetic disorders, and call for further studies on the role of this enzyme in the modulation of insulin-receptor phosphotyrosine pathways.

Acid Phosphatase↗

PubMed1983

Influence of glucoregulation with continuous subcutaneous insulin infusion on nerve conduction velocity and beat to beat variation in diabetics.

Limited and contrasting data are available on the relationship between metabolic control and diabetic neuropathy. In eight type I diabetics peripheral and autonomic neuropathy were studied, first in conditions of poor metabolic control and then after one and three months during which an improved control of glycemic levels had been obtained by continuous subcutaneous insulin infusion. Autonomic neuropathy was investigated by evaluating beat to beat variation during deep breathing; peripheral neuropathy by measuring maximum motor conduction velocity of peroneal and median nerves and sensory conduction velocity of median nerve. Our data showed significant improvement of motor conduction velocity in both nerves studied, whilst sensory conduction velocity did not show any significant variation. The changes observed in beat to beat variation in five subjects with initially abnormal scores might reflect an improvement in autonomic nervous function, even if long-term studies are needed.

Adult↗

PubMed2002

Glucose and insulin management in the post-MI setting.

Despite dramatic advances in the treatment of acute myocardial infarction (AMI) in recent years, patients with diabetes mellitus continue to experience disproportionately high morbidity and mortality. A substantial body of experimental and clinical data suggest that the ability of the heart to augment its energetic metabolism of glucose in the acute setting is critical to survival and functional recovery after AMI. Emerging evidence also suggests that chronic hyperglycemia may predispose to post-AMI ischemia and heart failure via adverse effects on coronary endothelial function and myocardial ultrastructure, energy metabolism, and gene transcription. A strong case can be made for intensive insulin-based control of glycemic level in the AMI patient with diabetes mellitus.

Blood Glucose↗

PubMed1991

Insulin and the paraventricular hypothalamus: modulation of energy balance.

The effects of insulin injections (0.1, 1, 10 and 40 mU) into the paraventricular hypothalamus (PVN) were investigated in an open-circuit calorimeter. Wistar rats were tested, with no food available during the tests. The 0.1 and 1 mU doses had no effects on either respiratory quotient or energy expenditure. The 10 mU dose increased respiratory quotient which indicates increased dependency on carbohydrates as an energy substrate. The same dose had no effects on thermogenesis. In contrast, the 40 mU dose decreased respiratory quotient which indicates increased dependency on fats as an energy substrate. The higher dose also increased thermogenesis. Since neither dose significantly affected locomotor activity, the metabolic data are not confounded with activity effects. These data indicate that insulin in the PVN produces a primary modulation of the metabolic parameters central to maintaining energy balance. In separate experiments, the 4 doses of insulin reduced food intake and body weight over a 24 h period. They also produced a dose-related increase in blood glucose concentration over a one hour period. Taken together, these findings are interpreted in a model in which insulin in the PVN acts as a signal indicating increased body fat. This increases thermogenesis, fat utilization and glycemic levels, and inhibits feeding. The net effect of this integrated metabolic-behavioural response is a regulatory reduction in body fat.

Animals↗

PubMed1993

Glucagon and the paraventricular hypothalamus: modulation of energy balance.

The effects of glucagon injections (25, 100 and 200 ng) into the paraventricular nucleus of the hypothalamus (PVN) were investigated in an open-circuit calorimeter. Wistar rats were tested, with no food available during the tests. High doses of glucagon (100 and 200 ng) produced small and short-lasting increases in energy expenditure. The independence of these changes from changes in locomotor activity suggests that the thermogenesis represents a primary modulation and is not secondary to increased locomotion. All three doses of glucagon produced long-lasting and dose-related increases in respiratory quotient which were unrelated to any changes in locomotor activity. As with the changes in energy expenditure, this dissociation indicates that the effects are not secondary to changes in locomotor activity. These data constitute the first evidence that glucagon in the PVN modulates the metabolic parameters central to energy balance. In separate experiments, the three doses of glucagon increased blood glucose concentration over a one hour period, but they did not affect food and water intake and body weight over 24 h. These findings suggest that glucagon normally acts on the PVN in conditions of increased body fat to initiate autonomic mechanisms which increase glycemic levels, thermogenesis and carbohydrate utilization. These data constitute the first direct evidence for the involvement of the PVN in the regulation of energy balance by glucagon. The main effect of glucagon in the PVN is anabolic in that it increases dependence on carbohydrates as an energy substrate which results in a sparing of fat reserves.

Animals↗

PubMed1991

Spontaneous recovery from non-insulin-dependent diabetes mellitus induced by neonatal streptozotocin treatment in spontaneously hypertensive rats.

We studied the long-term change in glycemic level in a model of non-insulin-dependent diabetes mellitus (NIDDM) induced by neonatal streptozotocin (STZ) treatment in spontaneously hypertensive rats (SHR). Two-day-old male SHR were intraperitoneally injected with 37.5 to 75.0 mg/kg of STZ or vehicle alone as control. According to nonfasting plasma glucose levels at 12 weeks of age, rats were divided into mild (less than 16.8 mmol/L) and severe (greater than or equal to 16.8 mmol/L) diabetes groups. In the mild diabetes group (n = 5), plasma glucose decreased significantly from 14.2 +/- 1.8 mmol/L (mean +/- SEM) at 20 weeks to 7.3 +/- 0.3 mmol/L at 52 weeks (P less than .05) with progressing age. At 52 weeks, overnight fasting plasma glucose levels were significantly lower and serum immunoreactive insulin (IRI) was higher than in controls, respectively (4.1 +/- 0.3 v 5.7 +/- 0.3 mmol/L, P less than 0.01; 625 +/- 50 v 409 +/- 50 pmol/L, P less than .05), and insulinoma was found in 60% of rats. Therefore, the recovery from hyperglycemia may be attributed to the development of insulinoma. In the severe diabetes group (n = 6), plasma glucose remained high until 28 weeks (27.2 +/- 1.5 mmol/L), but thereafter decreased with age, as it did in the mild diabetes group (13.7 +/- 3.5 mmol/L at 52 weeks, P less than .005). However, no insulinoma was found, and the mechanism for the recovery was unclear. The present study demonstrates that hyperglycemia spontaneously ameliorates in a neonatal STZ diabetes model of SHR, although this phenomenon may be strain-related.

Aging↗

PubMed1992

Vagally mediated feeding responses to phloridzin infusion in the rabbit.

Rabbits were infused with the plant glycoside, phloridzin, which blocks absorption of glucose across a number of bodily tissues. Feeding was dramatically increased in the first 0.5 h following phloridzin infusion into either the duodenum or the hepatic-portal vein of intact rabbits. Food intake covaried inversely with glycemic levels after phloridzin infusion into the hepatic-portal vein, but rabbits did not show a systematic relationship between blood glucose levels and food intake following duodenal infusion of phloridzin. When administered into the general circulation via the jugular vein, phloridzin did not elicit feeding. Finally, vagotomized rabbits did not show the hyperphagic response to phloridzin that was observed in intact rabbits. It was concluded that the feeding response to phloridzin is vagally mediated and appears to be induced by glucose transport inhibition at some peripheral site.

Animals↗