Carbohydrate intolerance after acute gastroenteritis--a disappearing problem in Polish children

The prevalence of carbohydrate intolerance in Polish children during an acute episode of gastroenteritis was determined. One hundred and seven consecutive children, less than 3 years old, with acute diarrhoea were enrolled into the study. Carbohydrate intolerance (diagnostic criteria: >0.5% reducing substances and stool pH less than 5.5) was diagnosed in 14/107 (13.08%) children: lactose intolerance was present in 12 (11.2%) patients; glucose polymer intolerance in 1 (0.93%) and monosaccharide intolerance in 1 (0.93%). The most important predisposing factor was rotavirus. In all cases the carbohydrate intolerance was transient, resolving within 5 days. Carbohydrate intolerance is also an infrequent problem in Polish children. Restriction of lactose-containing foods (use of lactose-free or low lactose formulas) for the majority of children with gastroenteritis does not seem to be justified.

Progression of normal glucose tolerance to impaired glucose tolerance or diabetes in the elderly

Factors predicting impared glucose tolerance (IGT) and diabetes (DM) were studied in a community-living population aged 70 years or over, with initial normal glucose tolerance (NGT). The baseline examinations from 1991 to 1992 included an oral glucose tolerance test (OGTT), physical examinations and questionnaires. The follow-up examinations in 1994 and 1995 comprised of an OGTT. One hundred and thirteen of the eligible 134 subjects, with baseline NGT, participated in the re-examinations. Thirty six percent of these subjects progressed to IGT and 3% to DM. Obesity was the best predictor of IGT or DM, and central obesity was also associated with them. In addition, abnormal progression of glucose tolerance was also associated with those aged greater than 80 years, with systolic blood pressure greater than 160 mmHg, diastolic blood pressure greater than 80 mmHg, fasting blood glucose value of greater than 5.3 mmol/l, and 2 h of blood glucose value greater than 6.8 mmol/l.

The effects of 20 days bed rest on serum lipids and lipoprotein concentrations in healthy young subjects

The effects of 20 days bed rest (BR) on serum lipids and lipoprotein concentrations were investigated in 23 healthy young subjects (13 males and 10 females, aged 19 to 25 yr.). After 20 days BR, VO2max was reduced in both genders, but body composition did not change. The ratio of glucose area to insulin area during an oral glucose tolerance test decreased gradually throughout BR, which suggested a decrease in insulin sensitivity. Estimated changes in plasma volume from the beginning of BR were largest at day 3 of BR (-9.1% in females and -3.4% in males) and seemed to return the initial level at the end of BR in both genders. The increase in serum triglycerides and the decrease in high density lipoprotein (HDL) cholesterol, and apolipoprotein AI were observed in both genders during BR. In a smaller study of 4 males and 5 females, 20 days BR was associated with a decrease in HDL, cholesterol, a decrease in apolipoprotein AI and apolipoprotein AII, decrease in a plasma postheparin lipoprotein lipase activity and an increase in very low density lipoprotein triglyceride. Overall, the data suggested that the decrease in lipoprotein lipase activity and insulin sensitivity may contribute to the impairment in HDL metabolism.

The clinical implications of impaired glucose tolerance

Impaired glucose tolerance (IGT) was introduced in 1979 as an intermediate category covering the grey area between unequivocal diabetes mellitus and risk free more normal glucose tolerance. The IGT group included those at high risk of subsequent development of non-insulin-dependent diabetes mellitus (NIDDM) but low risk of specific diabetic complications. Categorisation of subjects as IGT is hampered by the variability of the oral glucose tolerance test, but even those shown to be IGT only once are at increased risk of developing NIDDM. The relative roles of inheritance, fetal undernutrition, and environmental life style factors (physical inactivity and diet) in the aetiology and pathogenesis of IGT are discussed, with all contributing. The prevalence of IGT in different populations has now been widely studied with values ranging from 2 to 25% in adults. Rates of progression to NIDDM also vary widely from 2 to 14% per year. Risk factors for progression are discussed. IGT also carries an increased risk of development of cardiovascular disease (CVD) and forms part of the "metabolic syndrome". The role of insulin resistance as a common aetiological factor is briefly reviewed. Finally, possible means of treatment of IGT are listed with the intent of delaying the onset of diabetes and CVD, which is of obvious clinical importance.

[Hereditary background and natural history in glucose-intolerance group]

For non-obese IGT, frequency of 1st degree DM relatives was 29.9%, a rate higher than normal. NIDDM development rate was higher in IGT with family history of DM (86.9/1000 PY) than in IGT without family history (75.4/1000PY). For IGT-2 (2hr. PG > or = 170 mg/dl), the rate was higher in the group with family history (140.1/1000 PY) than that without family history (113.6/1000 PY). The odds ratio for NIDDM was 1.76 with obesity and 1.55 with family history. With regard to the natural course, plasma glucose (PG) increased slowly with rising of IRI over a long period, then PG increased suddenly without rising IRI and reached NIDDM onset. From these results, intervention trials for prevention of NIDDM are possible during long glucose-intolerance period.

[Glucose intolerance in chronic renal failure]

It has been recognized that glucose intolerance is a common finding in patients with chronic renal failure (CRF). Insulin resistance and impaired insulin secretion contribute to the pathogenesis of glucose intolerance. The resistance to insulin action is commonly observed in chronic renal failure and mainly due to impaired glucose uptake by muscle. In contrast, insulin secretion in response to hyperglycemia is variable: increased, decreased and normal. Recent studies reported that high PTH levels impaired insulin secretion from pancreatic islets. In this review, we mention the mechanism of glucose intolerance in chronic renal failure.

[Obesity and insulin resistance syndrome]

Obesity is commonly associated with insulin resistance. The etiology of insulin resistance syndrome such as syndrome X or deadly quartet is not clear. We have proposed visceral fat syndrome, in which fat accumulation is predominant in the intra-abdominal cavity, frequently accompanied by disorders of glucose and lipid metabolism, and also hypertension. Excess free fatty acid of the portal circulation may cause the enhancement of lipid synthesis and gluconeogenesis as well as insulin resistance, resulting in hyperlipidemia, glucose intolerance and hypertension and finally atherosclerosis. Enhanced production of PAI-1 by increased visceral fat may be partly responsible for the development of cardiovascular disease in patient with visceral fat assmulation.

[Pathogenesis and treatments of glucose intolerance with liver cirrhosis in men--lessons from the clinical cases of Fukuoka City Hospital, Department of Internal Medicine, Fukuoka, Japan]

More than 30% of the end stage liver cirrhosis was complicated by the impared glucose tolerance, in some of which insulin supplements may be required to control the blood glucose level. However, there are many unsolved issues on the cause and cares of hyperglycemia in cirrhotic men. Here, we presented a case of liver cirrhosis and hepatocellular caricnoma complicated by the severe glucose intolerance, and summarized our recent insulin therapy on the glucose intolerance of the decompensated liver cirrhosis in Fukuoka City Hospital, Department of Internal Medicine.

[Diabetes secondary to endocrinolopathies]

A number of endocrine disorders are associated with varying degrees of glucose intolerance. Sustained hypersecretion of hormones with actions antagonistic to insulin (e.g., GH, glucocorticoidos, catecholamines, glucagon) or which interfere with insulin secretion (e.g., catecholamines, hypokalemia) is often associated. And so, acromegaly, Cushing's syndrome, pheochromocytoma, primary aldosteronism, hyperthyroidism, glucagonoma and others are included in endocrine-associated diabetes. The glucose intolerance occurring secondary to endocrine disorders is usually moderate degree and overt diabetes with symptomatic hyperglycemia is an uncommon event, unless an underlying genetic diabetic diathesis also present in the same individual. The small subgroup of acromegalics(5-10%) with severe glucose intolerance requiring insulin therapy have low endogenous insulin levels and insulin responses that are markedly impaired. It has been suggested that these patients are really true diabetics. These are patients with NIDDM. Retinal, renal and neurological complications are uncommon in patients with endocrine-associated diabetes.

[Impaired glucose tolerance in liver and pancreas disease]

Impaired glucose tolerance(IGT) frequently occurs in patients with liver diseases. Because of the central role of the liver in carbohydrate metabolism, it is generally assumed that impaired hepatic metabolism plays a major role in the pathogenesis of IGT in liver disease. However, recent observation using glucose clamp techniques has demonstrated that the majority of patients with cirrhosis are characterized by peripheral hyperinsulinemia and insulin resistance of muscle tissues. Glucose intolerance in patients with chronic pancreatitis in related to impaired glucose-mediated insulin secretion, which is induced by the loss of B-cell mass in the pancreas. Patients with hemochromatosis have insulin resistance in the precirrhotic stage. The mechanism of insulin resistance, produced by iron overload, remains unknown.

[Pathogenesis of glucose intolerance in alcoholics]

Glucose intolerance and diabetes mellitus are both prevalent not only in alcoholic liver cirrhosis, but also in chronic alcoholics without cirrhosis. Nutritional properties, pharmacological effects, and metabolic alterations produced by alcohol intake due to excessive production of reducing equivalents play significant roles in the pathogenesis of ethanol-induced glucose intolerance. Gluconeogenesis from glycogen, fatty acids, amino acids, and lactate are also impaired during ethanol metabolism. Thus, ethanol-induced hypoglycemia is closely related to depressed hepatic gluconeogenesis produced by ethanol, whereas ethanol-induced hyperglycemia or diabetes is due to hepatic and tissue insulin resistance and impairment of pancreatic endocrine system.

[Mild glucose intolerance in the elderly]

Glucose tolerance has been shown to decline with age. Mechanisms of this phenomenon are not yet completely defined. The insulin response to glucose shows little change with age. The primary cause results from resistance to the ability of insulin to stimulate glucose uptake. Many factors, including composition of diet with regard to both caloric adequacy and carbohydrate content, decreased physical activity and decreased lean body mass, probably contribute to the insulin resistance. Mild glucose intolerance in the elderly, as in young adults, increases the risk for the development of overt diabetes mellitus and is a risk factor for the development of atherosclerotic diseases.

Late onset diabetes mellitus in patients with hereditary aceruloplasminemia

Aceruloplasminemia is a systemic degenerative disorder characterized by mutations in the ceruloplasmin gene, the absence of serum ceruloplasmin, and iron accumulation in the brain, liver, and other tissues. Iron is an important catalyst of oxyradical-mediated cellular and tissue injury, and beta-cells in the pancreatic islets are susceptible to the cytotoxic effects of oxidative stress. We report three patients with aceruloplasminemia who have late-onset diabetes mellitus (DM) and impaired glucose tolerance (IGT) as well as neurologic symptoms. Their basal lipid peroxide levels, measured as thiobarbituric acid-reactive products, in plasma samples were three times the values for the controls. This increased susceptibility to lipid peroxidation in patients with aceruloplasminemia suggests that free-radical-mediated tissue injury plays a role in the occurrence of DM and IGT.

High-fat hypercaloric diet induces obesity, glucose intolerance and hyperlipidemia in normal adult male Wistar rat

There is strong evidence that genetic factors contribute to the development of obesity in humans as well as laboratory animals. Another important factor leading to obesity is an increase in energy intake. However, it is difficult to make normal rats obese by controlling daily food intake. There is no report of normal adult male Wistar rats becoming obese and diabetic on a high-fat diet. The aim of the present study was, therefore, to make normal adult Wistar rats obese by infusing high fat and hypercaloric diet through the cannula without disturbing the free movement and to investigate the influence of an increase in the caloric intake on body weight and glucose metabolism. High-fat hypercaloric diet (360 kcal/kg body wt./day; H group) or control diet (180 kcal/kg body wt./day; C group) was continuously infused into the stomach of normal adult male Wistar rats weighing approximately 300 g through gastric cannulas for 27 days. On day 28 after a 24-h fasting, serum concentrations of aspartate aminotransferase, alanine aminotransferase, total cholesterol, triglyceride, phospholipid, and free fatty acids (FFA) were determined, and intragastric glucose loading test (2 g/kg body wt.) was performed. The average weekly body weight gain in the H group was twice as much as that of the C group (40.0 +/- 2.4 vs. 19.4 +/- 1.9 g/week, P < 0.001). Serum levels of triglyceride, phospholipid, total cholesterol, and FFA were significantly elevated in the H group compared to those in the C group. Liver weight in the H group was significantly higher than that in the C group and showed steatosis. Pancreas weight (-13%) as well as protein (-12%), amylase (-53%) and trypsin content (-26%) were all reduced, whereas pancreatic DNA content was significantly increased in the H group compared to those in the C group. Serum glucose and insulin concentrations before and after glucose loading in the H group were significantly higher than those in the C group. Moreover, the insulin response relative to glucose response in the H group was significantly high compared to that in the C group, indicating the presence of insulin resistance. These results indicate that feeding of high-fat hypercaloric diet makes normal Wistar male adult rat obese associated with hyperlipidemia, hyperinsulinemia, and glucose intolerance.

Alimentary hyperglycemia in patients with subtotal gastrectomy is associated with decreased insulin secretion but not with insulin resistance

BACKGROUND

It is not clear whether alimentary hyperglycemia in gastrectomized patients is related with glucose tolerance or not.

METHODS

Glucose tolerance, insulin secretion, and peripheral insulin sensitivity were evaluated in 36 patients who underwent subtotal gastrectomy for gastric cancer using the oral glucose tolerance test (OGTT), the intravenous glucose tolerance test (IVGTT) and the euglycemic hyperinsulinemic glucose clamp technique (Glucose clamp).

RESULTS

Patients were categorized into three groups by OGTT; 8 cases were in group I (normal), 19 cases in group II (alimentary hyperglycemia), and 9 cases in group III (glucose intolerance). Both glucose disappearance rate (K value expressed as, %/min) and insulinogenic index as determined by IVGTT were significantly lower in groups II (1.00 +/- 0.24, 0.21 +/- 0.18, respectively) and III (0.90 +/- 0.13, 0.11 +/- 0.14, respectively), compared with group I (1.58 +/- 0.71, 0.35 +/- 0.18, respectively). Peripheral insulin sensitivity as measured by glucose clamp was not decreased in groups II and III.

CONCLUSIONS

These results suggest that in patients with alimentary hyperglycemia, glucose tolerance was impaired due to a decreased pancreatic sensitivity to blood glucose and not due to insulin resistance.

Physical inactivity and glucose intolerance in the multiethnic island of Mauritius

The island nation of Mauritius, located in the southwest Indian Ocean, has a high prevalence of non-insulin-dependent diabetes mellitus (NIDDM) among all of its ethnic groups (Hindu and Muslim Indians, African-origin Creoles, and Chinese). These high rates of NIDDM among groups of varying genetic background provide strong support for the importance of environmental components in the etiology of the disease. Research in Mauritius using a simple activity scale has suggested that physical inactivity may be one of these components. The current investigation further examined the association between glucose tolerance and physical activity in middle-aged nondiabetic residents of Mauritius using a more extensive physical activity questionnaire (the Modifiable Activity Questionnaire). Excluding individuals with NIDDM, a statistically significant (P < 0.05) inverse relationship between physical activity and 2-h post-load glucose concentration was found for both males (rho = -0.14) and females (rho = -0.11). Stratifying by ethnic group, similar inverse correlations were observed in Hindu, Creole, and Chinese males, and in Hindu females (P < 0.05), as well as weaker relationships in Muslim males and Creole females (P < 0.10). Total physical activity remained an independent predictor of 2-h post-load glucose concentration after controlling for body mass index, waist-hip ratio, age, and family history of NIDDM. These data are supportive of a potentially important role of physical activity in the prevention of NIDDM in middle-aged inhabitants of Mauritius.

Resolving polyhydramnios: clinical significance and subsequent neonatal outcome

The objective of this study was to determine the clinical significance and neonatal outcome of patients with polyhydramnios that subsequently resolved prior to delivery. A retrospective review of 275 cases of polyhydramnios, defined as an amniotic fluid index of > or = 25.0 cm, identified 41 cases in which the amniotic fluid volume returned to normal prior to delivery. A total of 40 out of 41 patients with resolving polyhydramnios had a mild to moderate excess of amniotic fluid. There was a significant difference in the distribution of neonatal delivery weights between the study group and a matched control group. Twelve of 41 (29.3%) neonates from the study vs. none of the neonates in the control group were large for gestational age (p < 0.001). A total of 21 of 41 patients (51.2%) in the study group vs. three of 41 (7.3%) patients in the control group had at least minimal glucose intolerance (p < 0.01). We conclude that patients with resolving polyhydramnios have a significantly higher prevalence of glucose intolerance and fetal macrosomia than patients with normal pregnancies.

Short administration of metformin improves insulin sensitivity in android obese subjects with impaired glucose tolerance

In a double-blind, randomized, cross-over study, the metabolic effects of a short treatment with metformin (2 x 850 mg day-1 for 2 days and 850 mg 1 h before evaluation) were compared to those of placebo in 15 obese subjects (BMI: 33.2 +/- 0.9 kg m-2), with abdominal distribution of adipose tissue and impaired glucose tolerance. An intravenous glucose tolerance test (0.3 g glucose kg-1) was performed after each period of treatment. Areas under the curve (AUC0-180 min) were calculated for plasma glucose, insulin, and C-peptide levels. Glucose tolerance was estimated by the coefficient of glucose assimilation (KG). Insulin sensitivity (SI) and glucose effectiveness (SG) indices were calculated using Bergman's minimal model. Insulin secretion rate (ISR) was determined by deconvolution of plasma C-peptide levels and insulin metabolic clearance rate (MCR) was estimated by dividing AUC 1SR by AUC insulin. Fasting plasma insulin levels were reduced after metformin (89.3 +/- 15.9 vs 112.4 +/- 24.3 pmol l-1; p = 0.04). AUC glucose, KG and SG were similar in both tests. However, AUC insulin was reduced (39.7 +/- 6.5 vs 51.8 +/- 10.4 nmol min l-1; p = 0.02), while SI (6.98 +/- 1.14 vs 4.61 +/- 0.42 10(-5) min-1 pmol-1 l; p = 0.03) and insulin MCR (715 +/- 116 vs 617 +/- 94 ml min-1 m-2; p = 0.03) were increased after metformin. The demonstration that metformin rapidly improves insulin sensitivity should encourage further research to evaluate the long-term effects of metformin in android obese subjects with impaired oral glucose tolerance.

Loss of skeletal muscle mass with aging: effect on glucose tolerance

It is generally believed that aging results in glucose intolerance. Since skeletal muscle is the major site of glucose uptake following an oral glucose tolerance test (OGTT), it is reasonable to hypothesize that loss of muscle mass with aging causes glucose intolerance. Evidence against this concept comes from extensive data demonstrating the usefulness of the recommended procedures for performing an OGTT. This involves giving 75 g of glucose to all subjects regardless of body weight, and the criteria for categorizing glucose intolerance are the same for all individuals. That this works well, with no evidence that larger people have better glucose tolerance than smaller people, suggests that muscle mass does not usually play a role. Recent studies on humans and rats indicate that aging per se does not result in glucose intolerance. In most of those older people with decreased glucose tolerance, this problem appears to be due to accumulation of abdominal fat with development of insulin resistance. We conclude that the loss of muscle mass with aging does not usually result in glucose intolerance.

Studies in hypertriglyceridaemia, III: Glucose tolerance, insulin sensitivity and indices of adipose tissue lipolysis in randomly selected non-diabetic hypertriglyceridaemic Swedish men

Hypertriglyceridaemia, insulin resistance and glucose intolerance are conditions associated with an increased risk of coronary heart disease. In this study we have examined randomly selected nondiabetic hypertriglyceridaemic (HTG) males, 40-50 years (n = 65) and age-matched normotriglyceridaemic (NTG) controls (n = 61). The (mean +/- SD) insulin sensitivity index, as assessed by the Minimal Model method, was significantly lower in the HTG compared with the NTG group (3.69 +/- 2.96 vs. 6.29 +/- 3.38 x 10(-4) min-1 per mUL-1; P < 0.001). Thirty-eight per cent of the HTG group was glucose intolerant, compared with 8% in the NTG group (X2 = 13.16; P < 0.001). The glucose intolerant HTG sub-group had, when compared with the glucose tolerant one, significantly higher serum concentrations of apoB (1318 +/- 284 vs. 1094 +/- 312 mg L-1; P < 0.01) and glycerol (84 +/- 26 vs. 65 +/- 22 nmol L-1; P < 0.01). Serum FFA concentrations were, irrespective of glucose tolerance/intolerance, higher in the HTG than in the NTG group. By logistic regression analysis with the HTG/NTG state as the dichotomous variable, it was found that neither a low insulin sensitivity, nor glucose intolerance were independently linked with the HTG state. Instead, the lower insulin sensitivity of the HTG group was related to their higher body mass index. The higher frequency of glucose intolerance in the HTG group was explained by their higher mean serum apoB concentration, when compared with the NTG group. In conclusion, this study of a randomly selected of HTG group has confirmed the frequent coexistance of HTG, insulin resistance and glucose intolerance. The new important finding was that neither of these two latter conditions appear to be of direct pathogenetic importance for HTG.

Prevalence of diabetes mellitus and impaired glucose tolerance in a middle-aged Finnish population

OBJECTIVE

To describe the prevalence of previously diagnosed and undiagnosed diabetes and impaired glucose tolerance (IGT) by sex, marital status, employment, exercise behaviour, and body mass index (BMI), and to compare previously diagnosed and undiagnosed diabetic patients.

DESIGN

A survey of the total 55-year-old population living in a Finnish city on 1 October 1990. All the participants who were not on antidiabetic medication were invited for an oral glucose tolerance test (OGTT).

SETTING

Oulu, a city in northern Finland.

SUBJECTS

1,008 eligible subjects (456 men and 552 women), of whom 345 men (76%) and 435 women (79%) participated.

MAIN RESULTS

The prevalence of previously diagnosed diabetes was 6.1% in the men and 3.0% in the women and that of previously undiagnosed diabetes 4.5% of the men and 3.7% of the women. The prevalence of IGT was 28.6% in the men and 26.7% in the women. Diabetes was related to BMI, and previously undiagnosed diabetes was related to the amount of physical exercise in both sexes. One third of the undiagnosed diabetic men and half of the undiagnosed diabetic women were identified among the persons with marked obesity (BMI 30 kg/m2 or more). The group of previously diagnosed diabetic patients included a significantly greater proportion of retired people and people on sick leave than the group of undiagnosed diabetic persons.

CONCLUSIONS

Diabetes is common in middle-aged Finns. Undiagnosed diabetes was detected especially in persons with marked obesity who were not physically active.

Gestational diabetes mellitus: antenatal variables as predictors of postpartum glucose intolerance

OBJECTIVE

To determine whether antepartum variables can predict postpartum glucose intolerance.

METHODS

Glucose tolerance was assessed 6 weeks postpartum in 94 of 238 women with gestational diabetes using a 2-hour, 75-g oral glucose tolerance test (GTT). Selected antepartum variables were analyzed for predictive ability for postpartum glucose intolerance.

RESULTS

Of 238 patients, 94 (39%) returned for a GTT. Those returning and those not returning were similar in all variables. Postpartum glucose intolerance occurred in 34%: impaired glucose tolerance in 18%, overt diabetes in 16%. No single maternal, intrapartum, or neonatal variable was predictive of postpartum glucose intolerance in all cases. Predictive variables included: requirement for insulin (insulin versus diet: 25 versus 3% impaired glucose tolerance, 26 versus 0% diabetes; P = .001), poor glycemic control (any 2-hour postprandial blood sugar level of 150 mg/dL or higher: 34 versus 5% diabetes; P = .005), and the 50-g GTT value (200 mg/dL or higher: 32 versus 6% diabetes; P = .01). For insulin requirement, the relative risk (RR) was 17.28 (95% confidence interval [CI] 2.46-121.45), and for the above three variables combined, the RR was 19.68 (95% CI 2.88-134.2). When the insulin dose was at least 100 U/day, all patients had abnormal glucose tolerance postpartum (RR = 34.00, 95% CI 4.93-234.39).

CONCLUSIONS

Postpartum glucose screening is not warranted for women at low risk who do not require insulin during pregnancy. The incidence of postpartum glucose intolerance in this group is very low. Women with risk factors should receive postpartum screening. Patients receiving at least 100 U/day of insulin have a 100% incidence of postpartum glucose intolerance.

Glucose intolerance in chronic respiratory failure

A 75-g oral glucose tolerance test (OGTT) was performed on 18 patients with chronic respiratory failure and without fasting hyperglycemia, positive urine glucose, or hepatic/pancreatic disorders. Underlying diseases in these patients were pulmonary emphysema (11 cases, 61%), pulmonary tuberculosis (5 cases, 28%), and chronic bronchial asthma (2 cases, 11%). The body mass index (mean +/- SD, 17.6 +/- 2.2 kg/m2, P < 0.001) in these patients was significantly lower than that (23.8 +/- 3.1 kg/m2) in normal subjects. The OGTT results showed an impaired glucose tolerance pattern in 9 cases (50%) and a diabetes mellitus pattern in 6 cases (34%). The mean two-hour plasma glucose value in the patients was 9.8 mmol/L. However, insulin secretion responded well to glucose loading. These results suggest that a high proportion of chronic respiratory failure patients may have an intolerance for glucose loading but a normal insulin secretion pattern.

[Problems raised by the definition and epidemiology of type 2 (non-insulin-dependent) diabetes throughout the world]

Many studies of Type 2 (non-insulin-dependent) diabetes mellitus assume that the condition is homogeneous and clearly defined. There are, however, several problems with these assumptions. Thus, definition of Type 2 diabetes is one of exclusion of other types (insulin-dependent, malnutrition-related, gestational and other rarer types) and inevitably contains a heterogeneous group of disorders the aetiology of which is largely unclear, and separation from the insulin-dependent type can be problematic. Diagnosis is also imprecise in asymptomatic subjects due to the lack of accurate diagnostic tools and lack of clear distinction of impaired glucose tolerance. An alternative to the oral glucose tolerance test is urgently needed. Epidemiological studies of Type 2 diabetes and its complications are also fraught with difficulties due to variability of the oral glucose tolerance test, potential problems in glucose measurement, heterogeneity, population selection and problems in international comparisons due to differing age ranges and life expectancy. Great care is needed in all studies of Type 2 diabetes to ensure that the groups under study are properly selected, well-defined and fully described.

Impaired glucose tolerance in hypertension is associated with impaired insulin release independently of changes in insulin sensitivity

OBJECTIVE

To assess the contribution of insulin release and glucose disposal by insulin-dependent and insulin-independent mechanisms to overall glucose tolerance in hypertension.

DESIGN AND METHODS

Minimal model analysis of insulin and glucose data from frequently sampled intravenous glucose-tolerance tests from 21 non-diabetic, newly diagnosed hypertensives, and from 21 age- and weight-matched normotensive controls, was performed to obtain indices of glucose tolerance, beta-cell function and insulin sensitivity.

RESULTS

Intravenous glucose tolerance (defined as the glucose disappearance rate constant) was significantly correlated with the minimal model parameters for insulin sensitivity, glucose effectiveness or insulin-independent glucose uptake, and first- and second-phase beta-cell responsiveness (phi 1 and phi 2). First-phase insulin release, expressed either as the area under the insulin-time curve between 0 and 10 min or as the ratio of that area to total insulin area was also correlated with glucose tolerance. Despite similar basal insulin and glucose concentrations, glucose tolerance was clearly diminished among the hypertensives. This could not be accounted for by insulin resistance or by changes in insulin-independent glucose uptake. Insulin release was diminished, as evidenced by the lower phi 2 among the hypertensives. phi 2 was inversely correlated with systolic (r = -0.44, P < 0.003) and diastolic (r = -0.42, P < 0.006) blood pressures. These differences were independent of body weight. Hypertensives also exhibited a lower fractional clearance rate for insulin.

CONCLUSION

Impaired insulin release might contribute to the glucose intolerance associated with hypertension, and this can occur in the absence of insulin resistance, which is not present in all subjects with essential hypertension.

Gestational diabetes: postpartum glucose tolerance testing

OBJECTIVE

Our purpose was to determine the incidence of and evaluate risk factors for postpartum glucose intolerance among predominantly black gestational diabetic women.

STUDY DESIGN

One hundred forty-five gestational diabetics underwent a standard 2-hour glucose tolerance test in the early puerperium according to the criteria of the National Diabetes Data Group.

RESULTS

Fourteen patients (10%) were diabetic and eight (5%) showed impaired glucose tolerance. Maternal age, race, or obesity did not predict abnormal postpartum glucose tolerance testing. The requirement of insulin for glucose control during gestation and gestational age at diagnosis were significantly associated with abnormal postpartum glucose tolerance (p < 0.0001 and p = 0.012, respectively). Multivariate analysis showed that only a requirement for insulin for glucose control was significant (p < 0.001).

CONCLUSION

Pregnancies complicated by gestational diabetes are at increased risk of glucose intolerance during the early postpartum period. Abnormal glucose tolerance occurs predominantly among those patients requiring insulin therapy during gestation or those diagnosed before 24 weeks' gestation.

Glucose Tolerance and Ageing

Hyperglycaemia, impaired glucose tolerance and non-insulin dependent diabetes become progressively more common with advancing age. The mechanism is insensitivity to the actions of insulin at the postreceptor level. Inadequate secretion of insulin and decreased hepatic sensitivity to insulin's action in suppressing glucose output also occur. The age-related changes may be made worse by obesity, renal failure or the ingestion of certain drugs, or may be lessened by increased physical activity.

Postnatal development in rat offspring delivered of dams with gestational hyperglycemia

OBJECTIVES

Our purpose was to test the hypotheses that (1) offspring delivered of dams with gestational hyperglycemia will show metabolic abnormalities and (2) dams with repeated pregnancy but without lactation experience will demonstrate abnormal glucose metabolism long after the delivery of the third litter.

STUDY DESIGN

Female rats went through three cycles of gestation-lactation, gestation-nonlactation, or no mating at all. The offspring were reared to 3 months of age, when half of each group were mated. Intravenous glucose tolerance testing was conducted at different times in dams and adult offspring.

RESULTS

Nonlactation dams showed gestational hyperglycemia, insulin resistance, and hyperlipidemia during the third pregnancy. Impaired intravenous glucose tolerance testing was also apparent 1 week and 3 months after weaning in dams. Adult offspring nursed by nonlactation dams were glucose intolerant and had higher hepatic gluconeogenic enzyme activities and higher lipid levels in the pregnant state.

CONCLUSION

Gestational hyperglycemia produced by repeated gestation without lactation could have a long-lasting effect on adult offspring.

[Glucose intolerance during interferon therapy in patients with chronic hepatitis type C]

A new side effect of interferon (IFN) therapy, glucose intolerance was investigated using insulin-clamp study. In 75 g oral glucose tolerance tests before and after the IFN therapy showed no significant difference, whereas clamp study showed a significant decrease of glucose disposal. Our data suggested that insulin resistance was the main reason for glucose intolerance observed during INF therapy in the patients with chronic active hepatitis C. Early detection and strict control of glucose intolerance could avoid the progress of glucose intolerance.

Roles of insulin resistance and beta-cell dysfunction in the pathogenesis of glucose intolerance in cystic fibrosis

The roles of insulin deficiency and insulin resistance in the pathogenesis of glucose intolerance in cystic fibrosis (CF) were evaluated in eight patients (aged 16.5 +/- 1.9 yr), four with normal glucose tolerance (NGT) and four with impaired glucose tolerance (IGT), and in seven healthy control (CN) subjects. First and second phase insulin secretions were evaluated during a hyperglycemic clamp. Hepatic glucose production (HGP) and insulin-stimulated glucose disposal were measured using [6,6-2H2]glucose and a stepwise hyperinsulinemic-euglycemic clamp. First and second phase insulin levels were significantly lower in both groups of CF patients compared with control values. There was an inverse relationship between glycohemoglobin level and first phase insulin (r = -0.81; P = 0.015) and second phase insulin (r = -0.97; P < 0.001). During the hyperglycemic clamp, the insulin sensitivity index was lower in CF-IGT, but not CF-NGT, compared with control values (6.66 +/- 1.79, 12.82 +/- 1.61, and 13.02 +/- 1.78 mumol/kg.min/pmol.L, respectively; P < 0.05). Basal HGP and fasting plasma glucose were higher in CF vs. CN [24.8 +/- 2.9 vs. 16.9 +/- 1.4 mumol/kg.min (P = 0.036) and 5.8 +/- 0.2 vs. 5.4 +/- 0.1 mmol/L (P = 0.035), respectively]. During the hyperinsulinemic euglycemic clamp, insulin-stimulated glucose disposal was significantly lower in CF-IGT (45.68 +/- 4.87 mumol/kg.min) vs. CF-NGT (78.99 +/- 1.34 mumol/kg.min) and CN (71.74 +/- 6.88 mumol/kg.min). Insulin sensitivity was lower in CF-IGT vs. CF-NGT (7.04 +/- 0.86 and 14.38 +/- 0.84 mumol/kg.min/pmol.L; P < 0.05). We conclude that 1) glycohemoglobin is a strong correlate of insulin deficiency in CF; and 2) glucose intolerance in this group of CF patients occurred as a consequence of concomitant insulin deficiency and insulin resistance.

Pathogenesis of glucose intolerance and diabetes mellitus in cirrhosis

Glucose intolerance and diabetes mellitus are both prevalent in cirrhosis, yet the pathogenesis of impaired glucose metabolism remains unknown. Therefore insulin secretion (hyperglycemic clamp, +125 mg/dl), insulin sensitivity (euglycemic hyperinsulinemic insulin clamp, +10 microU/ml and +50 microU/ml), whole-body glucose oxidation (indirect calorimetry) and glucose turnover ([6,6-2H2]glucose isotope dilution) were evaluated in a homogenous group of cirrhotic patients with glucose intolerance (n = 7) or frank diabetes mellitus (n = 6). The results were compared with those obtained in control subjects (n = 8). In glucose-intolerant patients, whole-body glucose uptake (mainly reflecting glucose utilization by muscle) was significantly impaired in patients during both insulin infusions as a result of decreased stimulation of the two major intracellular pathways of glucose disposal--nonoxidative glucose disposal (i.e., glycogen synthesis) and glucose oxidation. Hepatic glucose production was normal in the basal state and was normally suppressed during stepwise insulin infusion (by 65% and 85%, respectively, p = NS vs. controls). Hyperglycemia-induced increases of plasma C-peptide concentrations were comparable to those in controls (p = NS). In diabetic patients, insulin-mediated glucose uptake was significantly reduced, mainly because of impaired non-oxidative glucose disposal. Glucose oxidation appeared to be reduced, too. Hepatic glucose production was significantly increased in the basal state (3.03 +/- 0.24 vs. 2.34 +/- 0.10 mg/kg min, p < 0.02) and during insulin infusion (+50 microU/ml: 0.67 +/- 0.17 vs. 0.13 +/- 0.08 mg/kg min, p < 0.05) compared with that in controls. Both the first and second phases of beta-cell secretion were significantly reduced in response to steady-state hyperglycemia (both p < 0.01 vs. control values). In conclusion, glucose intolerance in cirrhosis results from two abnormalities that occur simultaneously: (a) insulin resistance of muscle and (b) an inadequate response (even when comparable to that of controls) of the beta-cells to appropriately secrete insulin to overcome the defect in insulin action. Diabetes mellitus in insulin-resistant cirrhotic patients develops as the result of progressive impairment in insulin secretion together with the development of hepatic insulin resistance leading to fasting hyperglycemia and a diabetic glucose tolerance profile.

Insulin sensitivity and metabolic clearance rate of insulin in cystic fibrosis

We have evaluated the metabolic clearance rate (MCR) of insulin and insulin sensitivity in 12 older patients with cystic fibrosis (CF) using the hyperinsulinemic euglycemic clamp method. Compared with a control group matched accurately for age and body mass index (BMI), the MCR of insulin was significantly enhanced in CF CF = 21.85 +/- 1.17 v controls = 16.01 +/- 0.92 mL/kg/min, P < .005), and this difference persisted after correction for lean body mass ([LBM] CF = 26.32 +/- 1.28 v controls = 19.09 +/- 1.09 mL/kg LBM/min, P < .005). Glucose disposal rates (M) were similar in the two groups during the clamp (CF = 7.28 +/- 0.41 v controls = 6.83 +/- 0.60 mg/kg/min, P > .5), but the insulin sensitivity index, M/I x 100 (I = steady-state insulin concentration), was markedly increased in the CF group (CF = 17.62 +/- 1.30 v controls = 11.75 +/- 0.71, P < .005). In conclusion, the MCR of insulin is enhanced in CF, which is in keeping with previous observations on drug metabolism in this disorder. Second, insulin sensitivity is increased in CF, and this points to a compensatory mechanism to counteract the insulinopenia.

Hyperlipidemia and glucose intolerance in the post-renal transplant patient

This review examines the relationship between renal transplantation and two important metabolic consequences: hyperlipidemia and glucose intolerance. Before cyclosporine, hypertriglyceridemia and hypercholesterolemia were common abnormalities that worsened in the cyclosporine era. In addition to obesity, steroid use, and reduced renal function, cyclosporine plays an independent role in elevating cholesterol levels, with particular reference to the modulation of the low-density lipoprotein receptor. Management includes maintaining low levels of steroid, manipulation of cyclosporine appropriately, diets low in fat and cholesterol, and an exercise program. Pharmacologic management in general revolves around the HMG-COA reductase drugs, which can be used safely if liver function tests and muscle enzymes are monitored. The unmasking of clinically important glucose intolerance occurs in 5 to 10% of patients in the cyclosporine era, not different from the earlier experience. Steroids and cyclosporine independently can worsen glucose tolerance to unmask a genetic predisposition to Type II diabetes in some and to even create glucose intolerance in otherwise normal individuals. Management is based on dietary and immunosuppressive drug dosing manipulations and the judicious use of oral hypoglycemic agents. Half of these recipients may ultimately need insulin. In summary, hyperlipidemia and glucose intolerance remain important metabolic consequences of renal transplantation that affect long-term patient survival unless recognized and treated.

Betel nut (Areca catechu) consumption and the induction of glucose intolerance in adult CD1 mice and in their F1 and F2 offspring

Many mutagenic nitroso compounds are also diabetogenic. Betel-nut (Areca catechu) chewing populations have an increased incidence of foregut cancers related to betel-nut nitrosamines which suggests that betel consumption could be diabetogenic. Young adult CD1 mice with a low spontaneous incidence of diabetes were fed betel nut in standard feed for 2-6 days. Single point (90 min) intra-peritoneal glucose tolerance tests were used to follow glucose tolerance up to 6 months of age. Glucose intolerance was defined as over 3 SD above mean control values. Glucose intolerance was found in 3 of 51 male and 4 of 33 female adult mice which were fed the betel diet (p < 0.01). Studies on the progeny of these mice are presented separately for animals studied in Aberdeen (Group 1) and London (Group 2). In matings of Group 1 betel-fed parents glucose intolerance was found in 4 of 25 male and 1 of 22 female F1 offspring, with significant hyperglycaemia in F1 males born to hyperglycaemic but not to normoglycaemic mothers (p < 0.01). In the F2 generation 4 of 23 males and 1 of 16 females and in the F3 generation 1 of 16 males and 0 of 20 females were glucose intolerant. In the Group 2 studies where betel-fed parents were mated to normal controls glucose intolerance was found in 10 of 35 male and 10 of 33 female F1 progeny (p < 0.005), and mean islet areas were increased in offspring of betel-fed parents (p < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Food habits in Aborigines and persons of European descent of southeastern Australia

As part of a study of risk factors for glucose intolerance and heart disease in Australian Aborigines and persons of European descent, we elicited the prevalence of food habits that may be associated with high fat and high salt intakes. Interview data were gathered from population-based samples in country towns and visitors to an Aboriginal health service in a state capital city, all in southeastern Australia. Among persons aged 13 years and over, the frequency of eating takeaway food as a meal was categorised as monthly or less, weekly, more than once per week, and daily or more often. The prevalence of eating such meals was higher among city Aborigines than those living in the country town; the prevalence was lowest among the country-town Europeans (chi 2 = 184, 6 df, P < 0.001). The prevalence of adding salt during cooking and food consumption was higher among Aborigines compared with Europeans. Among country-town Aboriginal males aged 35 or under, 25 of 40 (63 per cent) added salt to cooked food 'most of the time', compared with 66 of 185 (36 per cent) Europeans (chi 2 = 9.8, P = 0.002). Among Aboriginal females, 47 of 64 (64 per cent) were in the highest category of salt use, compared with 35 of 190 (18 per cent) of Europeans (chi 2 = 66.3, P < 0.001). About one-third of country-town Aboriginal males used dripping to fry food, but in the other ethnicity, gender and location groups, vegetable oil was the most frequent choice. The main differences in food habits were associated with ethnicity, rather than location.(ABSTRACT TRUNCATED AT 250 WORDS)

Spontaneous glucose intolerance in the progeny of low dose streptozotocin-induced diabetic mice

Multiple low doses of streptozotocin (LDS) induce low-incidence diabetes mellitus in Balb/cHan and high-incidence diabetes in CD-1 mice. We studied offspring of diabetic parents in both strains. Group 1 consisted of litters from control mice with no streptozotocin treatment. Group 2 litters had an LDS diabetic mother and a control father, group 3 litters had control mother with LDS diabetic father, and group 4 litters had both, LDS diabetic mother and father. Diabetes was induced by 5 x 40 mg streptozotocin per kg on five consecutive days. Progeny of diabetic mothers showed a state of reduced glucose tolerance associated with reduced glucose disappearance during intravenous glucose tolerance test and increased insulin secretion of isolated islets of Langerhans. These metabolic abnormalities predominated in the male litters of both strains of mice. Amniotic insulin was increased in diabetic mothers during pregnancy. No histologic abnormalities were observed in group 2 progeny. Pancreases in male offspring of LDS diabetic CD-1 fathers (group 3) were studied for insulitis. Insulitis was found in 40% of mice with normal glucose tolerance. A single subdiabetogenic dose of streptozotocin (40 mg/kg) induced insulitis in 90% of pancreases accompanied by reduced insulin release of isolated islets. By contrast, male Balb/cHan progeny of diabetic fathers failed to develop insulitis. In conclusion, we found (1) parental LDS diabetes was transmitted more often to male offspring, (2) maternal LDS diabetes was associated with hyperinsulin secretion and glucose intolerance in the offspring and (3) paternal LDS diabetes was accompanied by insulitis and insulin secretion deficiency in CD-1 progeny.

Glucose tolerance and insulin secretion in pancreatic cancer

While the association between pancreatic cancer and diabetes is well recognized, little is known about glucose tolerance and insulin secretion in patients with this tumour. Thirty patients with pancreatic cancer not complicated by diabetes, 10 with nonpancreatic cancer, and 10 healthy subjects were studied for glucose tolerance and insulin secretion in response to an oral glucose load. Twenty of the 30 patients with pancreatic cancer (70%) had impaired glucose tolerance compared with none of the patients in the other two groups. In most of these 20 patients' insulin responses were higher than those of patients with non-pancreatic cancer or healthy subjects. The results indicate that about two-thirds of patients with pancreatic cancer have abnormal glucose tolerance; this intolerance is associated with elevated insulin secretion, suggesting that it may be due to a peripheral resistance to insulin.

Indications for enteric tube feedings in oral and maxillofacial surgery

The catabolic effects of surgical trauma and sepsis have long been recognized. Oral and maxillofacial surgical patients represent a unique group in that their surgery and its effects on the stomatognathic system may adversely affect the ability to receive adequate nutrition. This article discusses some basic nutritional principles and describes the indications and guidelines for enteric tube feeding in this patient population.

Reversible impairment of glucose tolerance in patients with endemic fluorosis. Fluoride Collaborative Study Group

Endemic fluorosis is a condition resulting from prolonged ingestion of drinking water which contains excess fluoride. Studies on rats have suggested that fluoride toxicity may produce glucose intolerance and abnormalities in insulin secretion. We studied glucose and insulin profiles following an oral glucose load in patients with endemic fluorosis. Twenty-five young adults (age range, 15-30 years) with endemic fluorosis, and an equal number of matched healthy control subjects with normal fluoride intake were studied. Impaired glucose tolerance was demonstrated in 10 of 25 (40%) patients with endemic fluorosis. Patients with impaired glucose tolerance had significantly higher fasting serum immunoreactive insulin (p < 0.05), higher fasting serum fluoride (p < 0.001), and a significantly lower fasting glucose to insulin ratio than that in patients with normal glucose tolerance (p < 0.001) or control subjects (p < 0.05). The fasting serum fluoride levels correlated positively with the area under the glucose curve (r = 0.80, p < 0.01) in patients with impaired glucose tolerance. Interestingly these abnormalities could be reversed when the village was provided drinking water with fluoride levels within acceptable limits. The present study shows that chronic fluoride toxicity in humans could result in significant abnormalities in glucose tolerance which are reversible upon removal of the excess fluoride.

Glucose metabolism in Ullrich Turner syndrome: long-term effects of therapy with human growth hormone. German Lilly UTS Study Group

The effects of GH therapy on glucose metabolism in 72 Turner patients treated with human GH (HGH) 2, 3 or 4 IU/m2/day for 2 years are reported. OGTTs were performed at 0, 3, 12 and 24 months. The overall frequency of glucose intolerance was 9.7% before therapy and did not change under HGH. No change in HbA1c and fasting glucose values occurred. Integrated blood sugar values in the OGTT (area under the curre) did not change with 2 and 3 IU but were significantly elevated over control after 2 years with 4 IU. Insulin secretion was not significantly affected over time with 2 IU, whereas 3 and 4 IU produced significant increases which persisted after 2 years. Results indicate that glucose homeostasis is maintained under GH therapy at the expense of a compensatory increase in insulin secretion which persists at higher GH dosages.

Non-insulin dependent diabetes mellitus: a phenomenon of ageing?

The aetiopathogenisis of non-insulin dependent diabetes (NIDDM) is complex and the role of age in this process difficult to study. From epidemiological and clinical studies evidence emerges for a strong genetic component. Environmental factors comprise possibly lifestyle and convincingly obesity. The interplay between genetic and environmental factors in the pathogenesis of NIDDM is still speculative and requires further research in order to reduce the incidence of this condition.