Mean Fasting Blood Glucose Levels Research Articles

Physiological Variables and Diabetic Status

A random sample of 568 participants in the Tecumseh, Mich, study, aged 30 to 59 years, was stratified according to blood glucose concentration to select a high proportion of diabetics. Subjects were categorized as overt diabetics, chemical or probable diabetics, or nondiabetics. Diabetic groups and nondiabetics were compared for levels of blood glucose, plasma insulin, serum cholesterol, serum triglyceride, blood pressure, and contours of glucose and insulin curves. Overt diabetics had high mean fasting blood glucose levels. Challenged diabetics had significantly higher concentrations of all variables except cholesterol than nondiabetics, even after adjustment for age and adiposity. Glucose intolerance, adiposity, and sex influenced variables independently. Risk of atherosclerosis is partly attributable to persistent hyperglycemia and related metabolic abnormalities in overt diabetics. Postchallenge diabetics have subtle hyperglycemia but a high frequency of other risk factors. Recent developments suggest that control of blood glucose may become feasible and useful in the prevention of cardiovascular disease in overt and challenged diabetics.

C-Peptide reserve in insulin-dependent diabetes. Comparative responses to glucose, glucagon and tolbutamide.

Residual beta cell secretory capacity was assessed in short term (2 months to 2 years) and long term (5 to 8 years) insulin-dependent diabetics by measurement of serum C-peptide immunoreactivity during three provocative tests: glucose, tolbutamide, and glucagon. Minimal C-peptide secretion could be detected in only one out of seven long term diabetics by the stimulatory tests. All seven short-term diabetics responded to at least one provocative test of beta cell reserve, although these responses were blunted. The greatest C-peptide responses occurred after glucagon administration (mean increase 0.62 pmol/ml) in short-term responders. Patients who responded to one test did not necessarily respond to another stimulus. There was no correlation between basal C-peptide levels and the ability to provoke further C-peptide secretion by any of the three tests. C-peptide responses did not correlate with % Haemoglobin A1c, mean fasting blood glucose levels, or mean blood glucose concentrations during an oral glucose tolerance test. The data indicate that stimulation tests are only useful in assessing endogenous beta cell reserve in patients with diabetes of less than 5 years duration. In diabetics of longer duration there is little insulin reserve above basal levels.

EFFECT OF DISCONTINUATION OF BIGUANIDE THERAPY ON METABOLIC CONTROL IN MATURITY-ONSET DIABETICS

Control of blood-glucose levels was monitored for 12 wk after withdrawal of biguanides in a group of 118 diabetic patients treated with biguanides (alone or in combination with sulphonylurea) from a population of 39 200. The mean fasting blood-glucose level rose during the first 2 wk from 9·2±0·3 to 11·3±0·4 mmol/l (p<0·001) and the mean urinary-glucose excretion from 11·7±3·7 g/24 h to 36·5±5.5 g/24 h (p<0·001), respectively. The change in blood-glucose concentration did not depend on age, sex, bodyweight, or duration of diabetes or biguanide treatment. The mean increase in blood-glucose was similar (2·1-3·1 mmol/l) in subjects with their initial blood-glucose level ≤6·0 mmol/l, 6·1-11·0 mmol/l, and ≥11·1 mmol/l. There were no changes in blood-lipids or bodyweight during the observation period. Biguanides reduced blood-glucose levels in most patients with maturity-onset diabetes. The hypoglycæmic effect was similar in subjects with normal and increased bodyweight and did not depend on the duration or severity of diabetes.

DOUBLE‐BLIND TRIAL OF METFORMIN IN THE THERAPY OF NONKETOTIC DIABETICS

Seventeen diabetics with normal renal function who were aged from 31 to 79 years who were already receiving from 10 mg to 20 mg of glibenclamide daily participated in a double-blind crossover trial of metformin (500 mg twice a day) for two months. After two months of metformin therapy, mean fasting and postprandial blood glucose levels were significantly lower than control values (9.9 mmol/L versus 12.4 mmol/L and 13.5 mmol/L versus 16.4 mmol/L; P= <0.001 and <0.01 respectively). In contrast, there was no difference between blood glucose levels while the patients received placebo and control blood glucose levels. There was no significant difference in effect on weight, fasting plasma lactate levels, fasting or postprandial plasma insulin levels, or the occurrence of side effects, between metformin and placebo. It is concluded that in selected diabetics whose condition is inadequately controlled with sulphonylurea therapy, significant improvement in diabetic control can be obtained by the addition of metformin in a low dose of 500 mg twice a day.

Simplified management of pregnancy complicated by diabetes.

Simple methods for the management of pregnancy complicated by diabetes are described. Emphasis was placed on keeping patients out of hospital, good control of diabetes and vaginal delivery at 38 weeks: using these methods, there were nine perinatal deaths in a consecutive series of 101 pregnancies complicated by diabetes. Four of the perinatal deaths were due to the respiratory distress syndrome. The patients whose diabetes was diagnosed during pregnancy had significantly heavier babies (18 pregnancies, mean birth weight 3337 g) than the established diabetics (83 pregnancies, mean weight 3011 g) despite significantly lower fasting blood glucose levels in the former and similar mean gestational ages at delivery. Mean fasting blood glucose levels for the whole series during the first, second and third trimesters were 9.0, 6.7 and 5.6 mmol/l respectively. The mean duration of antenatal stay in hospital for complications related to diabetes was 29 days. Diabetic retinopathy did not seem to be adversely affected by pregnancy.

Vascular complications and long-term administration of oral hypoglycemic agents in patients with diabetes mellitus.

To investigate the effect of long-term administration of oral hypoglycemic agents upon the development of vascular complications, a retrospective follow-up study was carried out on 214 diabetic patients for a period of 8 years. These patients were divided into three groups: 38 patients treated with diet alone (group I), 125 patients with sulfonylurea (group II) and 51 patients with insulin (group III). The mean fasting blood glucose levels were generally well controlled through the period of observation in each group. Blood pressure had been treated, but hypertension was observed in 2 to 10% of each diabetic group at the eighth year. Hypoglycemia, albuminuria and ketonuria occurred more frequently in group III than in the other groups. There had been no remarkable changes in serum lipids of these three diabetic groups through the observation period. The percentages of the patients with diabetic retinopathy increased during the follow-up period and significant differences were noted among the three groups at the eighth year (p<0.025). In contrast, no significant difference was demonstrated in the percentage of the ischemic heart disease among these groups. When correlation coefficients between variables in each group were calculated, it was difficult to find out any definite relationship between certain variables. The stepwise multiple-regression analyses suggested that the development of retinopathy or of abnormal ECG was affected by various factors. In addition, statistical analyses were performed on 152 deaths among 2100 diabetics who attended our Clinic between January 1, 1961 and August 31, 1976. The mortalities were 8.9% for the group with diet alone, 3.5% for the group with sulfonylureas and 11.9% for the group with insulin, and these values were different with a statistical significance (p<0.001). As a whole, 32 patients (21.7%) died of malignant neoplasma, 25 (16.4%) of renal diseases and 24 (15.8%) of cerebral vascular accidents. Fatal myocardial infarction and cardiac insufficiency were detected in 6 (3.9%) and 5 (3.3%) patients, respectively. The percentages of deaths from heart disease were low and no significant difference was observed in the mortality of cardiac events between the three groups. The results obtained in the investigation did not support the UGDP study.

Effects of oral glucose and protein load on plasma glucagon and insulin concentrations in small for gestational age infants.

This paper reports portal and peripheral blood glucose, insulin, and glucagon levels in small for gestational age (SGA) and appropriate for gestational age (AGA) newborns during the first 48 hr of life. These parameters were studied after an oral glucose and protein load (1 g/kg of each) after a 4-hr fast. In AGA and SGA infants, mean fasting blood glucose level was significantly higher in the portal vein than in the aorta (P less than 0.05). After the load, mean blood glucose level rose significantly in both vessels. The mean fasting plasma insulin level was low and was similar in both vessels. After the load in the AGA group mean plasma insulin level rose significantly at 45 min both vessels (P less than 0.05) (52.1 +/- 37.2 muU/ml in aorta and 91.8 +/- 75.3 muU/ml in portal vein). In the SGA group, the insulin response was minimal in the aorta and in the portal vein; the increase was significant only in the portal vein (P less than 0.05) at 180 min (47.1 +/- 25.3 muU/ml). The mean fasting plasma glucagon level was higher in the portal vein than in the aorta in both groups (P less than 0.05). After the load in AGA infants plasma glucagon rose significantly from 193 +/- 55 pg/ml at zero time to 290 +/- 76.8 pg/ml at 180 min (P less than 0.01) in the aorta but not in the portal vein. In the SGA group, the mean plasma glucagon did not rise significantly in the aorta or in the portal vein (from 231.2 +/- 54.3 pg/ml at zero time to 293.7 +/- 123.5 pg/ml at 180 min in the portal vein). The molar ratio of insulin to glucagon (I/G) rose significantly after the load in the portal vein in both groups of infants (AGA 2.48 +/- 2.06 at zero time to 5.08 +/- 4.06 at 180 min; SGA infants from 2.2 +/- 1.98 at zero time to 4.16 +/- 2.59 at 180 min). When both groups of infants were compared there was no significant difference either in the aorta or in the portal vein in mean blood glucose, mean plasma level, and plasma glucagon level. It is concluded that SGA and AGA premature infants are similar in regard to secretion of both pancreatic hormones in the first days of life.

A study of glucose tolerance, serum transaminase and lipids in women using depot-medroxyprogesterone acetate and a combination-type oral contraceptive

The metabolic effects of the 3-month injectable preparation depomedroxyprogesterone acetate (DMPA; Depo-Provera) 150 mg and of the combined oral contraceptive Ovral (d-norgestrel .05 mg plus ethinyl estradiol .05 mg) in a Thai population were assessed in a longitudinal study. Subjects were 2 groups of 16 women each from the Family Planning Clinic. A rapid intravenous glucose tolerance test (IVGTT) was done on both groups and at 1 2 3 6 9 and 12 months after drug administration. Plasma insulin levels were determined before and at 1 9 and 12 months posttherapy. Serum transaminase activity (SGOT and SGPT) triglyceride and total cholesterol levels were also determined. Results of the IVGTT are given as K values (disappearance rate of glucos e %/minute). In the DMPA group at 12 months the 1st significant decrease in mean fasting blood glucose levels was noted. The serum triglyceride levels tended to be lower throughout the 12 months of observation. Total cholesterol levels were significantly decreased after 9 and 12 months of DMPA use. SGOT AND SGPT and body weights remained the same. The K values were significantly increased during the observation period but less so toward the end of the period. Mean fasting plasma insulin was unchanged but some of the early plasma insulin responses were significantly increased. In the Ovral group the fasting blood glucose was significantly lower after 3 months of treatment. Serum triglyceride remained unchanged. Cholesterol levels tended to be lower during the first 6 months. SGOT and SGPT levels remained the same. Body weights were significantly increased. The mean K value did not change significantly but some were lower. Fasting plasma insulin remained the same but the plasma insulin responses to glucose load were significantly increased throughout the period particularly late during the observation period. Not all of the results agree with the works of some other investigators. It is concluded that DMPA caused a beneficial effect on carbohydrate metabolism without deterioration of lipid metabolism or liver function. Ovral did not induce any significant change in the K value although plasma insulin levels increased some during the test. Ovral did not induce any change in liver function or lipid metabolism except transient lowering of cholesterol values.

The hypoglycaemic action of metformin.

Summary Twenty-four-hour excretion of D-xylose after oral administration in nine diabetic patients, and of 3-0-methyl-D-glucose in six patients, showed no significant change after treatment with metformin. There was, however, a significant reduction in mean fasting blood glucose levels in thirteen patients from 160 to 115 mg/100 ml (P &amp;lt;0·001), and the intravenous glucose tolerance improved in twelve of these patients (P &amp;lt;0·01), during treatment with metformin. It is concluded that the hypoglycaemic action of metformin does not depend primarily on an intestinal effect.

Genetic selection for high and low fasting blood glucose levels in mice. I. Fasting blood glucose levels, glucose tolerance and isolated tissue studies.

Swiss-Hauschka mice have been selected for high (HG) and low (LG) fasting blood glucose (FBG) levels for four generations. All matings were brother to sister. Differences in mean FBG levels have remained relatively constant (20 to 30 mg%) between the two lines since initiation of selection (p<0.001). Body weights have declined more rapidly with inbreeding in the LG line as compared to the HG line through F3, but no further decline was noted in the F4 generation. Fasting serum immunoreactive insulin (IRI) levels were variable and mean levels for the two lines did not differ significantly. A comparison of glucose tolerance data between F3 HG and LG line animals showed generally higher mean glucose levels in the HG line in both fasted and randomfed states. The mean delta glucose levels during the test, however, were nearly identical in both lines. A dietary influence on glucose tolerance was shown. Severalin vitro tissue studies revealed no significant differences in hepatic glycogen and pancreatic insulin content between HG and LG line animals. Isolated tissue sensitivity to insulin appeared indistinguishable between the lines; however, hepatic gluconeogenesis and retinal glucose-6-14C oxidation rates in HG line mice may be enhanced.

Obesity and pancreatic islet hyperplasia in the Mongolian gerbil.

In a colony of Mongolian gerbils maintained on a standard laboratory diet, occasional obese animals were found. Obesity developed in animals of both sexes and was either transitory or permanent. The mean fasting blood glucose level in non-obese and obese gerbils was 83 and 105mg/100 ml, respectively. Glucosuria and hyperglycemia were found only in a few obese animals, whereas the glucose tolerance was decreased in most obese gerbils. — The endocrine pancreas of the obese animals was morphologically either normal or more often hyperplastic, sometimes with the appearance of adenomatous islets. Theβ-cells possessed prominent Golgi complex and endoplasmic reticulum, and sparse granulation. Large, granule-poor, cells and mitotic figures were seen in the islets. Degenerative changes occurred in theβ-cells of diabetic animals. — It is suggested that the maintenance of the gerbils under laboratory conditions with free access to laboratory diet plays a major role in the development of obesity and that the endocrine pancreas of these animals has a good capacity for hyperplasia that often is sufficient to maintain normo-glycemia in obese animals, although the glucose tolerance is decreased.

GLUCOSE TOLERANCE, INSULIN AND GROWTH HORMONE IN INFANTS OF GESTATIONAL DIABETIC MOTHERS

Twelve control and nine gestational diabetic mothers (GDM) and their infants were studied at birth. All GDM were obese. The criteria for selection of control mothers were a negative family history for diabetes, a normal oral glucose tolerance test, and the presence of obesity. The mean birth weights of the infants were not significantly different. All infants received a 3-hour oral glucose tolerance test (OGTT), completed within the first 24 hours of life. Glucose, serum immunoreactive insulin and growth hormone levels were determined. The mean glucose values obtained at the time of delivery revealed no significant differences between the GDM and the control mothers or between the infants of gestational diabetic mothers (IGDM) and the normal control infants. At birth, the mean seruni insulin levels of the GDM and the IGDM were both significantly higher than were their control GDM and IGDM. The OGTT was performed between 0 and 21 hours after birth and after a 4-hour fast. The mean fasting blood glucose level of the IGDM was significantly lower than that of the control infants, p≤.02. However, during the OGTT, the normal control infants showed a disposal of glucose similar to the IGDM. No evidence of hyperinsulinemia was observed in either the control infants or the infants of gestational diabetic mothers. The mean growth hormone values for the infants at the time of delivery revealed no significant differences between the two study groups. During the OGTT, the IGDM had significantly higher mean growth hormone values at both 60 and 120 minutes.

Juvenile diabetes mellitus, a deficiency in insulin.

The plasma insulin, growth hormone, nonesterified fatty acids and glucose responses to the oral ingestion of glucose, the intravenous administration of tolbutamide and the infusion of arginine were studied in fourteen newly diagnosed juvenile diabetic children. Fasting plasma insulin levels did not differ significantly between diabetic and normal children, although the mean fasting blood glucose level of the diabetic children was threefold greater than that of the normal subjects No detectable plasma insulin response was observed in the diabetic subjects during all three tests. Fasting plasma growth hormone levels and plasma growth hormone responses were similar in both normal and diabetic children. The fasting free fatty acid level of the diabetic children was significantly higher than in normal children, but fell during all three tests. With use of a variety of sensitive procedures, no antibodies to human insulin were demonstrable in the sera of newly diagnosed juvenile diabetics.