Presence Of Impaired Glucose Tolerance Research Articles

Changes in Maternal Glucose Metabolism after the Administration of Dexamethasone for Fetal Lung Development

Aims. Antenatal dexamethasone administration for fetal lung development may impair maternal glucose tolerance. In this study, we investigated whether glucose and insulin levels differed among singleton and twin pregnancies and pregnancies with impaired glucose tolerance (IGT) after treatment with dexamethasone. Methods. Singleton pregnancies, twin pregnancies, and pregnancies with IGT between 28 and 33 weeks of gestation whose mothers were treated with dexamethasone were enrolled in this study. Exclusion criteria included gestational hypertension, diabetes, renal disorders, and infectious diseases. The fasting plasma glucose and insulin levels were checked before administration and 24 h, 48 h, and 72 h after treatment was completed. Results. Mean glucose levels were significantly higher in the twin pregnancy and IGT groups at 24 h and 48 h after the administration of dexamethasone than those in the singleton pregnancy group (P < 0.05). Although there was no significant difference in glucose levels before administration and 72 h after dexamethasone administration among the three groups, insulin levels in the IGT group were significantly higher (P < 0.05). Insulin levels in the singleton pregnancy group at 24 h and 48 h after treatment were significantly lower than in the twin and IGT groups. Conclusion. The effects on maternal fasting blood glucose and insulin levels of dexamethasone administrated to promote fetal lung maturation correlated with embryo number and the presence of IGT.

Body Adiposity and Type 2 Diabetes: Increased Risk With a High Body Fat Percentage Even Having a Normal BMI

Obesity is the major risk factor for the development of prediabetes and type 2 diabetes. BMI is widely used as a surrogate measure of obesity, but underestimates the prevalence of obesity, defined as an excess of body fat. We assessed the presence of impaired glucose tolerance or impaired fasting glucose (both considered together as prediabetes) or type 2 diabetes in relation to the criteria used for the diagnosis of obesity using BMI as compared to body fat percentage (BF%). We performed a cross-sectional study including 4,828 (587 lean, 1,320 overweight, and 2,921 obese classified according to BMI) white subjects (66% females), aged 18-80 years. BMI, BF% determined by air-displacement plethysmography (ADP) and conventional blood markers of glucose metabolism and lipid profile were measured. We found a higher than expected number of subjects with prediabetes or type 2 diabetes in the obese category according to BF% when the sample was globally analyzed (P < 0.0001) and in the lean BMI-classified subjects (P < 0.0001), but not in the overweight or obese-classified individuals. Importantly, BF% was significantly higher in lean (by BMI) women with prediabetes or type 2 diabetes as compared to those with normoglycemia (NG) (35.5 ± 7.0 vs. 30.3 ± 7.7%, P < 0.0001), whereas no differences were observed for BMI. Similarly, increased BF% was found in lean BMI-classified men with prediabetes or type 2 diabetes (25.2 ± 9.0 vs. 19.9 ± 8.0%, P = 0.008), exhibiting no differences in BMI or waist circumference. In conclusion, assessing BF% may help to diagnose disturbed glucose tolerance beyond information provided by BMI and waist circumference in particular in male subjects with BMI <25 kg/m(2) and over the age of 40.

Microvascular retinopathy in subjects without diabetes: the Inter99 Eye Study

Retinal vascular lesions such as microaneurysms and haemorrhages, while typical of diabetic retinopathy, are also seen in subjects without diabetes where they are associated with elevated cardiovascular mortality. In theory, these lesions could be a consequence of past hyperglycaemia. We examined the prevalence and risk factors for retinopathy, including lens fluorescence, a biomarker of cumulative life-time glycaemia in adults without diabetes. Cross-sectional population-based study of 711 subjects without diabetes (WHO 1999 criteria) aged 30-60 years, including oral glucose tolerance testing, clinical and laboratory examinations, non-invasive ocular lens fluorometry and seven-field fundus photography. Retinopathy was present in 8.3% (CI(95) 6.3-10.3%) of subjects. Higher systolic blood pressure (SBP) (p = 0.032), increasing body mass index (BMI) (p = 0.014) and wider waist circumference (p = 0.014) were significantly associated with retinopathy after adjusting for age and sex. Retinopathy was not significantly related to long-term, short-term or current glycaemia (lens fluorescence, HbA(1c) , fasting plasma glucose). In the multivariate analysis, the odds ratio (OR) for retinopathy in subjects with SBP ≥160 mmHg compared to subjects with SBP <130 mmHg was 2.68 (CI(95) 1.07-6.70, p = 0.036) and in subjects with BMI ≥30 compared to subjects with BMI < 25 the OR for retinopathy was 2.14 (CI(95) 1.01-4.57, p = 0.049) when adjusting for both variables, age, sex, the presence of impaired glucose tolerance and impaired fasting glucose. Retinopathy in subjects without diabetes was associated with hypertension and obesity. The study found no evidence that microvascular retinopathy in non-diabetic subjects was a consequence of past hyperglycaemia.

Glucose tolerance and plasma testosterone concentrations in men. Results of the Asturias Study

Background and objectiveStudies in men have demonstrated a correlation between serum concentrations of androgens and sex hormone binding globulin (SHBG) with the presence of impaired glucose tolerance, diabetes and metabolic syndrome. The aim of this study was to evaluate circulating levels of total testosterone, SHBG, and bioavailable testosterone in the cohort of the Asturias Study and their association with the degree of glucose tolerance and metabolic syndrome. Patients and methodsThe study population consisted of 282 men aged 36 to 85 years old with normal concentrations of total testosterone. The degree of glucose tolerance and the presence of metabolic syndrome were evaluated. ResultsSerum concentrations of testosterone and bioavailable testosterone were negatively correlated with age, body mass index, waist circumference, blood glucose, glycosylated hemoglobin levels and insulin. Serum concentrations of total testosterone, bioavailable testosterone and SHBG were lower in men with glucose intolerance or diabetes than in those with normal glucose tolerance. After multivariate analysis, age and total testosterone levels were independent predictors of the presence of diabetes or glucose intolerance. The risk of glucose intolerance or diabetes mellitus was over 2.5 times higher in men with total testosterone levels in the lowest quartile than in those with total testosterone in the top quartile. ConclusionsIn this general population sample from Asturias, men with lower plasma concentrations of total testosterone - even when within the normal range - have an increased risk of glucose intolerance or diabetes, regardless of age and body mass index.

Prevalence and Prognostic Implications of Pre-Diabetic State in Patients With Heart Failure

Diabetes mellitus (DM) is a risk factor of poor prognosis in patients with heart failure (HF). The prevalence and prognostic impact of the pre-diabetic state, however, are not well understood. One hundred and thirty-six consecutive patients admitted due to HF were included in this prospective study. The 75-g oral glucose tolerance test (OGTT) was performed in all patients without known DM, and patients were classified into normal glucose tolerance (NGT), impaired fasting glucose (IFG), impaired glucose tolerance (IGT), and DM groups. Forty-two of the 136 patients had previously been diagnosed with diabetes. Of the remaining 94 patients without known diabetes, 35 (37.2%) patients were classified as NGT, 9 (9.6%) as having IFG, 37 (39.4%) were classified as having IGT, and 13 (13.8%) were newly diagnosed with DM. During follow-up, patients with DM or IGT had significantly lower major adverse cardiac and cerebrovascular event (MACCE)-free rates than NGT patients (P=0.006, P=0.036, respectively). IFG, however, was not significantly related to increased MACCE risk. The presence of IGT (hazard ratio [HR], 4.51; P=0.011) and DM (HR, 4.74; P=0.005) were independent predictors of MACCE even after multivariate analysis. IGT and DM contribute to adverse prognosis in patients with HF. It is feasible to perform diabetes screening using OGTT in patients with HF for risk stratification.

Prevalence of Diabetes and Cardiovascular Risk Factors of Industrial Area in Southern Poland

Diabetes mellitus (DM) is a serious health and social problem. We assessed the prevalence of DM and metabolic syndrome in an urban population in southern Poland. Sample of 782 subjects randomly selected from adult inhabitants of industrial district (23 442 voters registered) was invited. The response rate was 56% (including 85% of those aged over 50 years) mean age 53+/-15 years. 75 g OGTT and serum concentration of triglycerides, total cholesterol and HDL/LDL fractions were measured. The percentage+/-assessment error for the disorders were calculated assuming not-responders represented normal glucose tolerance. Prevalence of DM was 8.06+/-0.9% (7.15+/-1.25 M and 8.94+/-1.3 F) including 5.56+/-0.77% (5.56+/-1.13 M and 5.56+/-1.06 F) with known and 2.52+/-0.55 (1.59+/-0.64 M and 3.37+/-0.89 F) newly diagnosed. Impaired glucose tolerance (IGT and/or IFG) was found in additional 8.44+/-0.93% (6.09+/-1.17 M and 10.7+/-1.41 F). Extrapolated to the general population shown the prevalence 6.54+/-0.73% (5.8+/-1.02 M and 7.25+/-1.05 F). Features of the metabolic syndrome (IDF criteria) were found in 34% of the participants - 75% of patients with DM, 63% with glucose intolerance (IGT and/or IFG) and 19% of individuals with NGT (p<0.001 as compared to other groups). CONCLUSIONS The study confirmed high prevalence of diabetes mellitus with lower percentage of undiagnosed disease. Presence of impaired glucose tolerance allows to identify the high risk of metabolic syndrome and in consequence high risk of cardiovascular disease.

Overweight male personnel of the Japan Self-Defense Forces with body mass indices of 23.0-24.9 and obesity-related metabolic disorders.

To assess the validity of the criterion of overweight for Asian people that is recommended by Western Pacific Region of the World Health Organization. We carried out a cross-sectional analysis of the association between the criterion of overweight for ethnic Asian people--body mass indices (BMI) of 23.0-24.9 kg/m(2)--and the presence of obesity-related metabolic disorders among middle-aged Japanese men (n = 974, age range 51-59). The odds ratios (95% confidence interval) of overweight to those with normal weight (BMI < 23.0 kg/m(2)) were 1.61 (1.11-2.33) for the presence of impaired glucose tolerance, 1.95 (1.30-2.93) for hypertension, 2.22 (1.63-3.03) for hypercholesterolemia, 2.83 (2.02-3.97) for hypertriglyceridemia, and 2.06 (1.06-4.00) for hyperuricemia. Overweight was not associated with the presence of type 2 diabetes or with high gamma-glutamyl transferase in the present study (odds ratios: 1.09 and 1.05, respectively). Adjustment for age, rank, and lifestyle factors affected the results only slightly. Based on these results, we conclude that the Asian criterion of overweight appears to be rational in terms of its association with obesity-related metabolic disorders in male personnel of the Japan Self-Defense Forces in their fifties.

Long‐term effects of leisure time physical activity on risk of insulin resistance and impaired glucose tolerance, allowing for body weight history, in Danish men

AIMS: To determine if the level of leisure time physical activity (LTPA) in young adulthood in obese and non‐obese men reduces the risk of insulin resistance (IR) and impaired glucose tolerance (IGT) in middle age, and if such an effect is explained by the current level of LTPA, or by the body mass index (BMI) history preceding and subsequent to the assessment of LTPA.METHODS: Longitudinal study of groups of obese and randomly selected non‐obese men identified at around age 19, and re‐examined at mean ages of 32, 44 and 51. BMI was measured at all four examinations. LTPA was assessed by self‐administrated questionnaires at the last three examinations. IR and the presence of IGT was determined by an oral glucose tolerance test at the last examination.RESULTS: LTPA in young adulthood reduced the risk of IR and IGT in middle age throughout the range of BMI. Adjustment for the BMI history preceding and subsequent to the assessment of LTPA attenuated the association with IR and IGT, but active men remained at low risk of IR and IGT. Adjustment for subsequent and current levels of LTPA, smoking habits, alcohol intake, educational level and family history of diabetes had no notable influence on the results.CONCLUSION: LTPA appears to reduce the risk of IR and IGT, an effect which is not explained by the current level of physical activity, and only partially explained by the BMI history preceding and subsequent to the assessment of LTPA.

Long‐term effects of leisure time physical activity on risk of insulin resistance and impaired glucose tolerance, allowing for body weight history, in Danish men

To determine if the level of leisure time physical activity (LTPA) in young adulthood in obese and non-obese men reduces the risk of insulin resistance (IR) and impaired glucose tolerance (IGT) in middle age, and if such an effect is explained by the current level of LTPA, or by the body mass index (BMI) history preceding and subsequent to the assessment of LTPA. Longitudinal study of groups of obese and randomly selected non-obese men identified at around age 19, and re-examined at mean ages of 32, 44 and 51. BMI was measured at all four examinations. LTPA was assessed by self-administrated questionnaires at the last three examinations. IR and the presence of IGT was determined by an oral glucose tolerance test at the last examination. LTPA in young adulthood reduced the risk of IR and IGT in middle age throughout the range of BMI. Adjustment for the BMI history preceding and subsequent to the assessment of LTPA attenuated the association with IR and IGT, but active men remained at low risk of IR and IGT. Adjustment for subsequent and current levels of LTPA, smoking habits, alcohol intake, educational level and family history of diabetes had no notable influence on the results. LTPA appears to reduce the risk of IR and IGT, an effect which is not explained by the current level of physical activity, and only partially explained by the BMI history preceding and subsequent to the assessment of LTPA.

Impaired glucose tolerance is associated with changes in clinical and biochemical parameters in women with polycystic ovary syndrome

To characterize the phenotype of women with polycystic ovary syndrome with and without impaired glucose tolerance by determining various polycystic ovary syndrome-associated clinical and laboratory parameters. In a prospective clinical study, we evaluated a series of 102 Caucasian women with polycystic ovary syndrome. Women completed a detailed questionnaire and underwent a standardized oral glucose tolerance test. Various polycystic ovary syndrome-associated laboratory values such as hormonal and metabolic parameters were determined in these women and correlated to clinical data and the presence/absence of impaired glucose tolerance. Furthermore, the insulin resistance was calculated using the homeostasis model assessment index and correlated with clinical and biochemical parameters. Eighty-eight (86.3%) and 14 (13.7%) women were diagnosed as having non-impaired glucose tolerance and impaired glucose tolerance, respectively. Presence of impaired glucose tolerance was associated with an increased body mass index, increased body weight, elevated serum levels of bioavailable testosterone, insulin like growth factor-1, insulin, HbA1c, leucocytes, uric acid, alkaline phosphatase, hepatic C-reactive protein, and decreased serum levels of sex-hormone binding globulin. No association was ascertained with subfertility, hirsutism, and menstrual irregularities. We ascertained a positive correlation between the homeostasis model assessment index and body mass index, body weight, alkaline phosphatase, and hepatic C-reactive protein. Impaired glucose tolerance seems to be associated with a specific phenotype within polycystic ovary syndrome. This phenotype is more likely to present with biochemical parameters similar to an inflammatory reaction and a metabolic disorder.

Prevalence of non-traditional cardiovascular disease risk factors among persons with impaired fasting glucose, impaired glucose tolerance, diabetes, and the metabolic syndrome: analysis of the Third National Health and Nutrition Examination Survey (NHANES III).

To calculate the prevalence of non-traditional cardiovascular disease (CVD) risk factors across diabetes status and for persons with and without the metabolic syndrome. Data were analyzed from the Third National Health and Nutrition Examination Survey for normal plasma glucose [<100 mg/dl, n=4589]; impaired fasting glucose [IFG, 100-125 mg/dl, n=2008], diabetes [fasting glucose #10878; 126 mg/dl or diabetes medication, n=750]; and participants with and without the metabolic syndrome, n=1938 and n=5409, respectively. After adjustment for age, race, sex, body mass index, physical inactivity, cigarette smoking and alcohol consumption, a higher odds (p-trend < 0.01) of the metabolic syndrome, an elevated HOMA-insulin resistance index, chronic kidney disease, elevated C-reactive protein, high fibrinogen, and high white blood cell count was observed across diabetes status. After similar adjustment, the metabolic syndrome was associated with (odds ratio; 95% confidence interval) low apolipoprotein A1 (2.27: 1.30,3.96), high apolipoprotein-B (2.97: 2.03,4.34), a higher HOMA insulin resistance index (5.25: 4.16, 6.63), chronic kidney disease (2.27: 1.42, 3.63), and elevated markers of inflammation [high white blood cell count (1.55: 1.14, 2.10), and elevated C-reactive protein (1.46: 1.06, 2.00)]. Among participants with IFG, the presence of impaired glucose tolerance (IGT) was associated with a higher prevalence of the HOMA insulin reistance index, 32.3%, high fibrinogen, 18.5%, and elevated C-reactive protein, 13.2%, compared to persons with IFG alone, 19.7%, 13.3% and 5.7%, respectively (each p <== 0.05). In this representative of the US population, an increased prevalence of non-traditional CVD risk factors was present among persons with diabetes, IGT and IFG compared to IFG alone, and the metabolic syndrome.

Serum adiponectin in women with polycystic ovarian syndrome and its relation to clinical, metabolic and endocrine parameters

Several studies have demonstrated that low levels of serum adiponectin are present in obesity, insulin resistance, hypertension and hyperlipidemias. The aim of our study was to determine whether serum adiponectin level is different between patients with polycystic ovarian syndrome (PCOS) and control subjects. We also investigated relationships between various cardiovascular risk factors, levels of serum adiponectin and other hormones, such as androstendione, testosterone, estradiol, DHEAS, sex hormone binding globulin (SHBG), and leptin. We also analysed the correlation between serum adiponectin and free androgen index. Ninety-one women with clinical diagnosed PCOS and 53 healthy control subjects, carefully matched by body mass index (BMI) and age, were enrolled in the study. The fasting blood samples were obtained and all participants underwent an oral 75 g glucose tolerance test. The prevalences of impaired glucose tolerance (IGT), hypertension and hypertriglyceridemia were higher in the PCOS group. PCOS women had increased androgen concentrations and higher free androgen index and decreased level of serum SHBG. Lower serum adiponectin concentrations were observed among cases than in controls (median 13.7 microg/ml vs 17.8 microg/ml, p<0.001) despite being matched by BMI. In the PCOS group adiponectin levels correlated significantly with: BMI (r=-0.32, p=0.002), waist circumference (r=-0.32, p=0.003), waist-to-hip ratio (WHR, r=-0.38, p=0.001), triglycerides (r=-0.31, p=0.007), SHBG (r=0.30, p=0.003) and free androgen index (r=-0.29, p=0.02). In contrast, the adiponectin level does not appear to be related to total testosterone, DHEAS and leptin levels. The adiponectin and SHBG levels were found to be decreased in PCOS women with IGT compared to PCOS women with normal glucose tolerance, but after adjustment by BMI or WHR, the differences were no longer statistically significant. To exclude a possible confounding effect due to a higher prevalence of IGT in the PCOS group, this comparison was repeated for the subgroup of 58 PCOS women and 48 control women after excluding those with IGT. Neither adiponectin nor SHBG were significantly different between those subgroups. Multiple regression analysis revealed that serum adiponectin concentrations were best predicted by WHR, free androgen index and presence of IGT when all patients were considered. In PCOS subjects, the only independent predictor of adiponectin concentrations was glucose tolerance status. Lower adiponectin levels were observed in PCOS group than in control women, and these differences were probably due to higher prevalence of IGT in these cases.

Nodular Glomerulosclerosis in Cystic Fibrosis Mimics Diabetic Nephropathy

Background/Aims: Despite the cystic fibrosis gene product, the cystic fibrosis transmembrane conductance regulator, being widely expressed throughout the kidney, there is no clearly defined renal phenotype in patients with cystic fibrosis. As patients with cystic fibrosis survive longer progressive pancreatic destruction may lead to abnormal glucose tolerance and diabetes mellitus, which in the kidney may be associated with the characteristic changes of nodular glomerulosclerosis. Methods: The adult cystic fibrosis service at the Alfred hospital consists of a cohort of 200 patients. We describe 3 cystic fibrosis patients with impaired renal function who had renal biopsies performed as part of their diagnostic work-up. All patients had fasting plasma glucose levels, oral glucose tolerance tests and measurements of HbA_1c performed to assess for the presence of cystic fibrosis-related diabetes mellitus. Results: The renal biopsies of all 3 patients showed histological changes characteristic of diabetic nephropathy. In all cases described characteristic Kimmelstiel-Wilson nodules were present. However, in all 3 patients the presence of impaired glucose tolerance and diabetes mellitus was excluded using standard biochemical diagnostic criteria. Conclusion: We describe 3 adult CF patients, who on renal biopsy had histological evidence of nodular glomerulosclerosis in the absence of abnormal glucose metabolism. We speculate that the pro-inflammatory cytokine profile, typical of cystic fibrosis, predisposes to the lesions described.

Relation of serial changes in childhood body-mass index to impaired glucose tolerance in young adulthood.

The risk of type 2 diabetes mellitus is increased in people who have low birth weights and who subsequently become obese as adults. Whether their obesity originates in childhood and, if so, at what age are unknown. Understanding the origin of obesity may be especially important in developing countries, where type 2 diabetes is rapidly increasing yet public health messages still focus on reducing childhood "undernutrition." We evaluated glucose tolerance and plasma insulin concentrations in 1492 men and women 26 to 32 years of age who had been measured at birth and at intervals of three to six months throughout infancy, childhood, and adolescence in a prospective, population-based study. The prevalence of impaired glucose tolerance was 10.8 percent, and that of diabetes was 4.4 percent. Subjects with impaired glucose tolerance or diabetes typically had a low body-mass index up to the age of two years, followed by an early adiposity rebound (the age after infancy when body mass starts to rise) and an accelerated increase in body-mass index until adulthood. However, despite an increase in body-mass index between the ages of 2 and 12 years, none of these subjects were obese at the age of 12 years. The odds ratio for disease associated with an increase in the body-mass index of 1 SD from 2 to 12 years of age was 1.36 (95 percent confidence interval, 1.18 to 1.57; P<0.001). There is an association between thinness in infancy and the presence of impaired glucose tolerance or diabetes in young adulthood. Crossing into higher categories of body-mass index after the age of two years is also associated with these disorders.

Adrenocortical tumors: prevalence of impaired glucose tolerance and of "Paradoxical Rise" of cortisol during an oral glucose tolerance test.

Glucose tolerance and the behaviour of cortisol during an oral glucose tolerance test (OGTT) was investigated in 126 patients with adrenal "incidentalomas" (age: > 45 years) and in 129 age-matched controls. Impaired glucose tolerance (IGT) was found to be more common (p < 0.02) among patients with adrenal incidentalomas. Subdividing these patients by their body weight it was found that 29% (controls: 25%) of those with normal body weight (BMI 20 - 25 kg/m2) had IGT/DM. In overweight (BMI 25 - 30 kg/m2) and obese patients (BMI 30 - 40 kg/m2) the share of IGT/DM was 32% (controls: 19%) and 66% (controls 42%), respectively. The prevalence of a "paradoxical" rise in serum cortisol concentrations during the OGTT was slightly higher (p < 0.05) among patients with adrenal incidentaloma than among controls. Patients as well as controls with this abnormal behaviour of cortisol were characterized by lower basal serum cortisol concentrations (p < 0.01) but no association was seen with either the presence of IGT or with post-dexamethasone concentrations of serum cortisol. Thus both in patients with and without adrenal incidentalomas abnormal glucose tolerance is an age- and weight-dependent phenomenon unrelated to the post-prandial behaviour of serum cortisol concentrations.

Abdominal volume index. an anthropometry-based index for estimation of obesity is strongly related to impaired glucose tolerance and type 2 diabetes mellitus

Background Our objective was to develop an anthropometric-based index (abdominal volume index, AVI) for estimating overall abdominal volume and to determine its relationship with presence of impaired glucose tolerance (IGT) and type 2 diabetes mellitus (DM). Methods We conducted a cross-sectional, population-based study between November 1998 and June 2001 among 746 men and non-pregnant women randomly recruited from Durango City in northern Mexico. AVI was calculated using volume formulas for cylinder (V = πr 2h) and vertical cone V = (1/3)πr 2h. The formula developed was AVI = [2 cm (waist) 2 + 0.7 cm (waist-hip) 2]/1,000, which estimates overall abdominal volume between symphysis of pubis and xiphoid appendix and theoretically includes intra-abdominal fat and adipose tissue volumes. Results Receiver operating curve (ROC) scatter plot showed as best cut-off value of AVI for estimation of obesity, corresponding to 24.5 liters (L). Logistic regression analysis adjusted by age and sex showed higher odds ratio between AVI and IGT 1.6 (95% confidence interval [95% CI] 1.1–9.1, p = 0.01) as well as between AVI and DM 2.1 (95% CI 1.3–7.9, p = 0.001) than odds ratio (OR) estimated by other anthropometric obesity criteria such as waist-to-hip ratio, body mass index, truncated cone, and waist circumference. Conclusions AVI is a reliable and easy-to-calculate anthropometric tool for estimation of overall abdominal volume that is shown to be strongly related to IGT and DM.

Women with impaired glucose tolerance during pregnancy have significantly poor pregnancy outcomes.

This article tests the hypothesis that women with impaired glucose tolerance (IGT) have the same pregnancy outcomes as those of their counterparts with normal glucose tolerance. From December 1998 to December 1999, 84 of 90 antenatal care base units (ACBUs) under the Tianjin Antenatal Care Network in China participated in the first screening program for gestational diabetes mellitus (GDM). A total of 9,471 pregnant women under the care of participating ACBUs were screened. Of the women screened, 154 were positive for IGT. Of the 154 women, 102 opted for conventional obstetric care. The comparison group was 302 women of normal glucose tolerance (NGT). The initial screening consisted of a 50-g 1-h glucose test, and was carried out at 26-30 gestational weeks. Women with a serum glucose > or =7.8 mmol/l were followed up with a 75-g 2-h oral glucose tolerance test. The World Health Organization's diagnostic criteria for GDM were used. Women with IGT were at increased risk for premature rupture of membranes (P-ROM) (odds ratio [OR] 10.07; 95% CI 2.90-34.93); preterm birth (6.42; 1.46-28.34); breech presentation (3.47; 1.11-10.84); and high birth weight (90th percentile or 4,000 g) (2.42; 1.07-5.46); adjusting for maternal age, pregravid BMI, hospital levels, and other confounding factors. The presence of IGT in pregnancy is predictive of poor pregnancy outcomes.

Insulin Resistance and Hypertension

Insulin resistance, a common accompaniment of essential hypertension, increases cardiovascular risk both directly, and via its adverse effect on other cardiovascular risk factors. Decreasing insulin resistance by lifestyle modification including diet, weight loss, and physical exercise is an important component of therapy in all patients. With the exception of thiazide diuretics as monotherapy, the currently utilized classes of agent appear equally effective in lowering blood pressure in insulin resistant patients. Currently utilized agents do, however, differ substantially in their effect on insulin resistance and associated risk factors. Agents that diminish insulin resistance may have a rationale in treating insulin resistant patients with hypertension although a decisive recommendation about class of agent in this group of patients must await several prospective large scale trials currently underway. Lower intervention thresholds and lower therapeutic goals would appear to apply to hypertensive patients with insulin resistance especially in the presence of impaired glucose tolerance or overt diabetes mellitus.

Glucose metabolism in older adults: a study including subjects more than 80 years of age.

This study was undertaken to understand the dynamics of glucose metabolism in healthy non-diabetic subjects older than age 80 (old-old) compared with subjects aged 61 to 79 (young-old), as well as to compare healthy older subjects with impaired glucose tolerance (IGT) with older subjects with normal glucose tolerance (NGT). A cross sectional, observational study. A university hospital clinical research center. There were 28 community-dwelling adults, 10 older than age 80 and 18 aged 61 to 79. Thirteen of these people had NGT and 15 had IGT. Subjects were not taking any medication that interfered with glucose tolerance. Status of glucose tolerance was determined by an oral glucose tolerance test categorized as NGT or IGT according to WHO criteria. Insulin sensitivity (SI) and glucose effectiveness (SG) were assessed using a tolbutamide-assisted intravenous glucose tolerance test (IVGTT). The data were analyzed using the Minmod modeling program. Glucose tolerance (K(g)) and the acute insulin response to glucose (AIRg) were calculated from the IVGTT. There were no significant differences between the young-old and old-old in body mass index or in plasma glucose, insulin, or C-peptide levels in the fasting state or during the OGTT. Values for K(g), SI, SG, and AIRg from the IVGTT were similar in the two age groups. When the subjects were classified by glucose tolerance status, the subjects with NGT had age, gender, and body mass index similar to the subjects with IGT. Older people with IGT had a lower K(g) and tended to have higher fasting glucose and similar fasting insulin compared with people with NGT. IGT subjects had lower SI and tended to have lower SG. The AIRg in IGT subjects tended to be low rather than high when compared with older people with NGT. Otherwise healthy adults more than 80 years of age have measures of glucose metabolism similar to people aged 61 to 79. The presence of IGT in older adults is associated with insulin resistance, regardless of patient age. We hypothesize that the lack of pancreatic islet compensation for insulin resistance may contribute to impaired glucose tolerance in older adults.

Pancreatic α-Cell function in idiopathic reactive hypoglycemia

Idiopathic reactive hypoglycemia (IRH) is a well-documented but overdiagnosed syndrome. The presence of transient hypoglycemia and enhanced insulin secretion and/or increased insulin sensitivity before the onset of IRH is well documented. However, the data regarding glucagon secretion are sparse. Therefore, this study assessed glucagon and insulin responses to (1) oral ingestion of 100 g glucose oral glucose tolerance test (OGTT) and (2) a 100-g protein meal after an overnight fast in a randomized sequence at intervals of 7 to 10 days in five subjects with previously well-documented IRH and six normal subjects. Basal plasma glucose and insulin levels were not significantly different in both groups. However, basal glucagon was significantly higher ( P < .025) in IRH subjects (347 ± 83 ng/L) compared with normals (135 ± 20 ng/L). In IRH subjects during the OGTT, hypoglycemia (2.7 ± 0.11 mmol/L) occurred at 150 ± 16 minutes and was preceded by a markedly higher ( P < .01) peak glucose concentration (11.7 ± 0.6 mmol/L) at 36 ± 6 minutes in comparison to normals (8.8 ± 0.4 mmol/L), indicating the presence of impaired glucose tolerance in these subjects. Similarly, the plasma insulin increase was significantly higher ( P < .01) but delayed in IRH subjects compared with normals. In contrast, glucagon suppression was not significantly different in both groups, although glucagon failed to increase following hypoglycemia in IRH. During a protein meal, plasma glucose declined in both groups, with a significantly ( P < .05) greater decrease in IRH subjects (−0.8 ± 0.2 mmol/L) compared with normals (0.5 ± 0.1 mmol/L). However, the glucagon increase was significantly ( P < .01) blunted in IRH subjects (61% ± 15%) in comparison to normals (152% ± 39%). Thus, basal hyperglucagonemia with normal glucose concentration may suggest the presence of a hyposensitivity of the glucagon receptor in IRH. Moreover, the lack of appropriate suppression during the OGTT despite marked hyperglycemia, the lack of an increase at the onset of hypoglycemia, and the inhibited response to a protein meal in IRH subjects compared with normals denote altered glucagon secretion in IRH. Therefore, it is likely that glucagon receptor downregulation and impaired glucagon sensitivity and secretion may contribute to postprandlal hypoglycemia in IRH.