Initial Oral Glucose Tolerance Test Research Articles

Bihormonal dysregulation of insulin and glucagon contributes to glucose intolerance development at one year post-delivery in women with gestational diabetes: a prospective cohort study using an early postpartum 75-g glucose tolerance test.

Gestational diabetes mellitus (GDM) is known to be a significant risk factor for the future development of type 2 diabetes. Here, we investigated whether a precise evaluation of β- and α-cell functions helps to identify women at high risk of developing glucose intolerance after GDM. Fifty-six women with GDM underwent a 75-g oral glucose tolerance test (OGTT) at early (6-12 weeks) postpartum. We measured their concentrations of glucose, insulin, proinsulin and glucagon at fasting and 30, 60 and 120 min. At 1-year post-delivery, we classified the women into a normal glucose tolerance (NGT) group or an impaired glucose tolerance (IGT)/diabetes mellitus (DM) group. Forty-three of the 56 women completed the study. At 1-year post-delivery, 17 women had developed IGT/DM and 26 women showed NGT. In the early-postpartum OGTTs, the IGT/DM group showed a lower insulinogenic index, a less glucagon suppression evaluated by the change from fasting to 30 min (ΔGlucagon 30 min), and a higher glucagon-to-insulin ratio at 30 min compared to the NGT group. There were no significant between-group differences in proinsulin levels or proinsulin-to-insulin ratios. Insulinogenic index <0.6 and ΔGlucagon 30 min >0 pg/mL were identified as predictors for the development of IGT/DM after GDM, independent of age, body mass index, and lactation intensity. These results suggest that the bihormonal disorder of insulin and glucagon causes the postpartum development of glucose intolerance. The measurement of plasma insulin and glucagon during the initial OGTT at early postpartum period can help to make optimal decisions regarding the postpartum management of women with GDM.

Non-fasting OGTT versus Fasting OGTT for screening of Hyperglycaemia in Pregnancy (HIP).

Objectives:To compare the reliability of non-fasting oral glucose tolerance test (OGTT) versus fasting OGTT for screening of hyperglycaemia in pregnancy (HIP).Methods:This cross sectional analytic study was conducted by the Department of Obstetrics & Gynaecology, Isra University Karachi Campus from October 2016 to April 2017. A total of 225 pregnant women irrespective of gestational age were included in the study. They underwent non fasting 75 grams OGTT. Venous plasma glucose was done 02 hours after the glucose load. Same women were advised to come again within three to seven days for fasting OGTT. Venous plasma glucose (VPG) was estimated in fasting and 2 hours post glucose load.Results:Using the non-fasting OGTT, out of 204 women, 32 were diagnosed with hyperglycemia. All these 204 women were again called for fasting OGTT three to seven days after the initial non-fasting OGTT. Only nine were diagnosed with hyperglycemia, out of these nine women, seven women who were screen positive on non-fasting OGTT were found to be screen positive on fasting OGTT as well. However, only two women were additionally diagnosed with hyperglycemia who were initially screen negative on non-fasting OGTT. The non-fasting OGTT has diagnosed HIP with sensitivity of 77.7%, specificity of 87.1%, positive predictive value of 21.8% and negative predictive value of 98.8%.Conclusion:The use of the non-fasting OGTT at first antenatal visit may be a practical approach to detect the HIP as screening and diagnostic tool in the resource constrained settings.

Repeat OGTT at 34 - 36 Weeks to Detect the Late Occurrence of GDM: A Descriptive Cross-Sectional Study Conducted at the Professorial Unit, Teaching Hospital Peradeniya, Sri Lanka

Aim: Evaluation of the occurrence of glucose intolerance after 34 - 36 weeks in pregnant mothers attending the Teaching Hospital, Peradeniya. Materials & Method: This is a descriptive cross-sectional study carried out from October 2017 to March 2018 among 183 pregnant mothers attending antenatal clinic at Teaching Hospital Peradeniya. After informed consent a repeat Oral Glucose Tolerance Test (OGTT) was done among the pregnant mothers, at period of amenorrhoea of 34 - 36 weeks, whose initial OGTT values were normal. Gestational diabetes was diagnosed according to the NICE guideline cut off values and the percentage of late occurrence of Gestational diabetes (GDM) was analyzed. Results: Mean age of the population was 29.1 years and the age range in this group was 18 to 45 years and the majority (73.9%) of women were primipara. There were 3.3% of teenage pregnancies and 14% of mothers were over 35 years. Majority (59.7%) of mothers underwent repeat OGTT test at 34 weeks of gestation and the rest (40.3%) underwent test between 34 to 36 weeks of gestation. Although the mean BMI was 23.74, 9.7% of mothers were obese (>30 kg/m2), 30.3% of mothers were pre-obese (25.0 - 29.9 kg/m2). 8.2% of mothers were diagnosed with Gestational diabetes at 34 - 36 weeks whose initial OGTT values were normal. Conclusion: In view of reducing feto-maternal morbidity and mortality, considering a repeat OGTT at a later gestation (34 - 36 weeks of gestation) should be considered in mothers, whose initial OGTT values are normal as Sri Lanka is a high risk country for GDM. Clinical Significance: The study may play an important role in guideline alteration process and screening for gestational diabetes in Sri Lankan set-up.

Who Is Enrolling? The Path to Monitoring in Type 1 Diabetes TrialNet's Pathway to Prevention.

To better understand potential facilitators of individual engagement in type 1 diabetes natural history and prevention studies through analysis of enrollment data in the TrialNet Pathway to Prevention (PTP) study. We used multivariable logistic regression models to examine continued engagement of eligible participants at two time points: 1) the return visit after screening to confirm an initial autoantibody-positive (Ab+) test result and 2) the initial oral glucose tolerance test (OGTT) for enrollment into the monitoring protocol. Of 5,387 subjects who screened positive for a single autoantibody (Ab), 4,204 (78%) returned for confirmatory Ab testing. Younger age was associated with increased odds of returning for Ab confirmation (age <12 years vs. >18 years: odds ratio [OR] 2.12, P < 0.0001). Racial and ethnic minorities were less likely to return for confirmation, particularly nonwhite non-Hispanic (OR 0.50, P < 0.0001) and Hispanic (OR 0.69, P = 0.0001) relative to non-Hispanic white subjects. Of 8,234 subjects, 5,442 (66%) were identified as eligible to be enrolled in PTP OGTT monitoring. Here, younger age and identification as multiple Ab+ were associated with increased odds of returning for OGTT monitoring (age <12 years vs. >18 years: OR 1.43, P < 0.0001; multiple Ab+: OR 1.36, P < 0.0001). Parents were less likely to enroll into monitoring than other relatives (OR 0.78, P = 0.004). Site-specific factors, including site volume and U.S. site versus international site, were also associated with differences in rates of return for Ab+ confirmation and enrollment into monitoring. These data confirm clear differences between successfully enrolled populations and those lost to follow-up, which can serve to identify strategies to increase ongoing participation.

Progression to Gestational Diabetes Mellitus in Pregnant Women with One Abnormal Value in Repeated Oral Glucose Tolerance Tests.

BackgroundWomen with one abnormal value (OAV) in a 100 g oral glucose tolerance test (OGTT) during pregnancy are reported to have an increased risk of adverse pregnancy outcomes. However, there is limited data about whether women with OAV will progress to gestational diabetes mellitus (GDM) when the OGTT is repeated.MethodsTo identify clinical and metabolic predictors for GDM in women with OAV, we conducted a retrospective study and identified women with OAV in the OGTT done at 24 to 30 weeks gestational age (GA) and repeated the second OGTT between 32 and 34 weeks of GA.ResultsAmong 137 women with OAV in the initial OGTT, 58 (42.3%) had normal, 40 (29.2%) had OAV and 39 (28.5%) had GDM in the second OGTT. Maternal age, prepregnancy body mass index, weight gain from prepregnancy to the second OGTT, GA at the time of the OGTT, and parity were similar among normal, OAV, and GDM groups. Plasma glucose levels in screening tests were different (151.8±15.7, 155.8±14.6, 162.5±20.3 mg/dL, P<0.05), but fasting, 1-, 2-, and 3-hour glucose levels in the initial OGTT were not. Compared to women with screen negative, women with untreated OAV had a higher frequency of macrosomia.ConclusionWe demonstrated that women with OAV in the initial OGTT significantly progressed to GDM in the second OGTT. Clinical parameters predicting progression to GDM were not found. Repeating the OGTT in women with OAV in the initial test may be helpful to detect GDM progression.

Elevated Intact Proinsulin Levels During an Oral Glucose Challenge Indicate Progressive ß-Cell Dysfunction and May Be Predictive for Development of Type 2 Diabetes.

Elevated fasting intact proinsulin is a biomarker of late-stage ß-cell-dysfunction associated with clinically relevant insulin resistance. In this pilot investigation, we explored the potential value of measuring intact proinsulin as a functional predictor of ß-cell exhaustion during an oral glucose tolerance test (OGTT). The study was performed with 31 participants, 11 of whom were healthy subjects (7 female, age: 59 ± 20 years), 10 had impaired glucose tolerance (IGT, 6 female, 62 ± 10 years), and 10 had known type 2 diabetes (T2DM, 5 female, 53 ± 11 years, HbA1c: 7.0 ± 0.6%, disease duration: 8 ± 5 years). During OGTT, blood was drawn after 0 hours, 1 hour, and 2 hours for determination of glucose and intact proinsulin. Five years later, patients were again contacted to assess their diabetes status and the association to the previous OGTT results was analyzed. The OGTT (0 hours/1 hour/2 hours) results were as follows: healthy subjects: glucose: 94 ± 8 mg/dL/140 ± 29 mg/dL/90 ± 24 mg/dL, intact proinsulin: 3 ± 2 pmol/L/10 ± 7 pmol/L/10 ± 5 pmol/L); IGT: glucose: 102 ± 9 mg/dL/158 ± 57 mg/dL/149 ± 34 mg/dL, intact proinsulin: 7 ± 4 pmol/L/23 ± 8 pmol/L/28 ± 6 pmol/L; T2DM: glucose: 121 ± 20 mg/dL/230 ± 51 mg/dL/213 ± 34 mg/dL; intact proinsulin: 7 ± 7 pmol/L/26 ± 9 pmol/L/27 ± 10 pmol/L). Five years later, all of the IGT and 2 of the healthy subjects had developed T2DM and one had devloped IGT. All of them had elevated 2-hour proinsulin values in the initial OGTT, while patients with normal intact proinsulin results did not develop diabetes. Elevated 2-hour intact proinsulin levels during OGTT were predictive for later type 2 diabetes development. Further studies need to confirm our findings in larger populations.

Spironolactone and Dimethylsulfoxide Effect on Glucose Metabolism and Oxidative Stress Markers in Polycystic Ovarian Syndrome Rat Model

Because polycystic ovarian syndrome (PCOS) is a risk factor for type 2 diabetes, the affected women can present frequently prediabetic states such as impaired fasting glycaemia and/or impaired glucose tolerance. The purpose of our study is to explore the effect of antiandrogenic spironolactone on glucose metabolism and oxidative stress (OS) parameters in oestradiol valerate (OV) induced PCOS rat model.72 female Wistar rats were distributed either to PCOS group (n=65, OV dissolved in sesame oil, 5 mg/0.4 ml), or to non-PCOS control group (n=7, sesame oil, 0.4 ml). After a month, ultrasound was performed to assess the ovarian morphology, and the results of an initial oral glucose tolerance test (OGTT) were used to identify the animals with altered glucose metabolism (AGM). Glucose transporter 4 (GLUT4) was evaluated from muscle biopsies, OS parameters were assessed from blood and muscle samples, and ovaries of 3 rats were removed for histopathological examination. Afterwards, the AGM group was divided in a treated PCOS group denoted as Sp+D (per os spironolactone dissolved in DMSO, 2 mg/0.2 ml), and a PCOS control treated with DMSO (0.2 ml). After one month of daily treatment, a final OGTT was performed. GLUT4 and OS parameters were again evaluated and ovaries were removed for histopathological examination.As compared to the values prior to the treatment, Sp+D reversed fasting hyperglycaemia (p<0.001), increased GLUT4 immunoreactivity in the perinuclear compartment (p<0.05) and translocation to plasmalemma (p<0.001) and improved superoxide dismutase (0.001<p<0.01) and glutathione peroxidase (0.001<p<0.01) activities, while reducing GSH level (0.001<p<0.01). Administration of DMSO alone decreased fasting hyperglycaemia (p<0.001) and 2-h glucose level (p<0.05) independently of GLUT4 translocation, improved superoxide dismutase (p<0.001) and glutathione peroxidase (p<0.05) activities in erythrocytes, reduced GSH level in serum (p<0.05) and diminished lipid peroxidation in muscle as compared to the values recorded before treatment (0.001<p<0.01).Our results showed that the Sp+D treatment improved antioxidant capacity and had a beneficial effect on metabolic deregulation in PCOS. Administration of DMSO had an unexpected hypoglycaemiant effect and improved OS parameters. This may represent an indirect proof of the role of oxidative stress and inflammation in PCOS and glucose metabolism abnormalities encountered in PCOS.

Protective Effect of Free and Bound Polyphenol Extracts from Ginger (Zingiber officinaleRoscoe) on the Hepatic Antioxidant and Some Carbohydrate Metabolizing Enzymes of Streptozotocin-Induced Diabetic Rats

This study investigated the hepatoprotective effects of polyphenols from Zingiber officinale on streptozotocin-induced diabetic rats by assessing liver antioxidant enzymes, carbohydrate-metabolizing enzymes and liver function indices. Initial oral glucose tolerance test was conducted using 125 mg/kg, 250 mg/kg, and 500 mg/kg body weight of both free and bound polyphenols from Z. officinale. 28 day daily oral administration of 500 mg/kg body weight of free and bound polyphenols from Z. officinale to streptozotocin-induced (50 mg/kg) diabetic rats significantly reduced (P < 0.05) the fasting blood glucose compared to control groups. There was significant increase (P < 0.05) in the antioxidant enzymes activities in the animals treated with both polyphenols. Similarly, the polyphenols normalised the activities of some carbohydrate metabolic enzymes (hexokinase and phosphofructokinase) in the liver of the rats treated with it and significantly reduced (P < 0.05) the activities of liver function enzymes. The results from the present study have shown that both free and bound polyphenols from Z. officinale especially the free polyphenol could ameliorate liver disorders caused by diabetes mellitus in rats. This further validates the use of this species as medicinal herb and spice by the larger population of Nigerians.

Glucose and C-Peptide Changes in the Perionset Period of Type 1 Diabetes in the Diabetes Prevention Trial–Type 1

OBJECTIVE—We examined metabolic changes in the period immediately after the diagnosis of type 1 diabetes and in the period leading up to its diagnosis in Diabetes Prevention Trial–Type 1 (DPT-1) participants.RESEARCH DESIGN AND METHODS—The study included oral insulin trial participants and parenteral insulin trial control subjects (n = 63) in whom diabetes was diagnosed by a 2-h diabetic oral glucose tolerance test (OGTT) that was confirmed by another diabetic OGTT within 3 months. Differences in glucose and C-peptide levels between the OGTTs were assessed.RESULTS—Glucose levels increased at 90 (P = 0.006) and 120 min (P < 0.001) from the initial diabetic OGTT to the confirmatory diabetic OGTT (mean ± SD interval 5.5 ± 2.8 weeks). Peak C-peptide levels fell substantially between the OGTTs (median change −14.3%, P < 0.001). Among the 55 individuals whose last nondiabetic OGTT was ∼6 months before the initial diabetic OGTT, peak C-peptide levels decreased between these two OGTTs (median change −14.0%, P = 0.052). Among those same individuals the median change in peak C-peptide levels from the last normal OGTT to the confirmatory OGTT (interval 7.5 ± 1.3 months) was −23.8% (P < 0.001). Median rates of change in peak C-peptide levels were 0.00 ng · ml−1 · month−1 (P = 0.468, n = 36) from ∼12 to 6 months before diagnosis, −0.10 ng · ml−1 · month−1 (P = 0.059, n = 55) from 6 months before diagnosis to diagnosis, and −0.43 ng · ml−1 · month−1 (P = 0.002, n = 63) from the initial diabetic OGTT to the confirmatory diabetic OGTT.CONCLUSIONS—It seems that postchallenge C-peptide levels begin to decrease appreciably in the 6 months before diagnosis and decrease even more rapidly within 3 months after diagnosis.

Oral glucose tolerance test in children and adolescents: positives and pitfalls.

To describe the glycaemic status (assessed by an oral glucose tolerance test (OGTT)) and associated comorbidities in a cohort of Australian children and adolescents at risk of insulin resistance and impaired glucose homeostasis (IGH). Twenty-one children and adolescents (three male, 18 female) (18 Caucasian, one Indigenous, two Asian) (20 obese, one lipodystrophy) referred to the Paediatric Endocrinology and Diabetes Clinic underwent a 2-h OGTT with plasma glucose and insulin measured at baseline, + 60 and + 120 min. If abnormal, the OGTT was repeated. The mean (SD) age was 14.2 (1.6) years, BMI 38.8 (7.0) kg/m2 and BMI-SDS 3.6 (0.6). Fourteen patients had fasting insulin levels >21 mU/L. Type 2 diabetes mellitus was diagnosed in one patient, impaired glucose tolerance (IGT) in four patients and impaired fasting glycaemia (IFG) in one patient. Despite no weight loss, only one patient had a persistently abnormal OGTT on repeat testing. Three patients with IGH were medicated with risperidone at the time of the initial OGTT. One patient who had persistent IGT had continued risperidone. The other two patients had initial OGTT results of IGT and diabetes mellitus type 2. They both ceased risperidone between tests and repeat OGTT showed normal glycaemic status. Use of fasting glucose alone may miss cases of IGH. Diagnosis of IGT should not be made on one test alone. Interpretation of glucose and insulin responses in young people is limited by lack of normative data. Larger studies are needed to generate Australian screening recommendations. Further assessment of the potential adverse effects of atypical antipsychotic medication on glucose homeostasis in this at-risk group is important.

Translation of the recommendations for the diagnosis of diabetes mellitus into daily clinical practice in a primary health care setting

Aims: to assess the implementation of 1985 recommendations for the diagnosis of diabetes (World Health Organization [WHO]) in a primary care setting, and the physician's attitude toward the diagnosis of diabetes mellitus (DM). Material and methods: subjects with a fasting plasma glucose (FPG)>6.1 mmol/l (≥110 mg/dl) and with previously unknown glucose tolerance status were identified retrospectively in a primary health care center during a 45-month period. The following variables were evaluated: anthropometric parameters, fasting plasma glucose and oral glucose tolerance test (OGTT) values, registration of a diagnosis of diabetes in clinical records, smoking status, lipid profile and blood pressure. Results: 1181 subjects with a FPG>6.1 mmol/l were identified (target population): 171 with a FPG>7.8 mmol/l and 1010 with a FPG between 6.1 and 7.7 mmol/l. In the latter group, an OGTT was performed in 553 subjects (54.8%) (173 yielded a diagnosis of diabetes). During the study period, diabetes was diagnosed in 29.1% ( n=344) of the target population. Following the 1985 WHO recommendations, a confirmatory diagnostic test was repeated in 92 (69.7%) subjects with a FPG between 7.8 and 11.0 mmol/l, and in 132 subjects (23.87%) who had already received an initial OGTT. The analysis of the diagnostic process followed by the different physicians revealed a high interindividual variability in terms of: proportion of cases diagnosed as diabetes by an OGTT (from 35.7 to 65.2), percentage of subjects with a FPG 6.1–7.7 mmol/l without an OGTT (7.33–70.27%), proportion of confirmatory OGTTs (0–57.89%), and percentage of misdiagnosed cases (1.16–6.34%). The percentage of subjects misdiagnosed was negatively correlated with the proportion of OGTT repetitions. Conclusions: 1985 WHO recommendations for the diagnosis of diabetes are only partially followed at a primary health care level. There is a high interindividual variability among physicians in the implementation of these recommendations that is associated with the misdiagnosis of diabetes.

Subscapular skinfold thickness distinguishes between transient and persistent impaired glucose tolerance: Study on Lifestyle-Intervention and Impaired Glucose Tolerance Maastricht (SLIM).

To assess whether adding anthropometric measurements to an oral glucose tolerance test (OGTT) can help to distinguish between transient and persistent impaired glucose tolerance (IGT). From the SLIM project (Study on Lifestyle-Intervention and IGT Maastricht), a study designed to evaluate whether diet and physical activity intervention can improve glucose tolerance in subjects at risk for diabetes, 108 subjects with IGT underwent a repeated OGTT 2-4 months after the initial OGTT. Following the second test, subjects were classified as transient IGT, or persistent IGT. Anthropometric measurements, including body mass index, waist and hip circumference, sagittal and transverse abdominal diameters and skinfold thickness measurements, were done during the second OGTT. Persistent IGT was diagnosed in 47 subjects (44%), transient IGT in 40 (37%), impaired fasting glucose in eight subjects (7%), and diabetes in 13 cases (12%). Two-hour blood glucose levels at the initial OGTT and subscapular skinfold thickness were significantly higher in subjects with persistent IGT (2-h blood glucose 9.8+/-0.1 mmol/l vs. 10.2+/-0.1 mmol/l for transient IGT and persistent IGT, respectively; subscapular skinfold thickness 25.4+/-1.4 mm vs. 29.8+/-1.2 mm for transient IGT and persistent IGT, respectively). After adjustment for age, sex and family history of diabetes mellitus, logistic regression indicated that 2-h blood glucose level during the initial OGTT represented the strongest predictor of persistent IGT (P<0.02), followed by subscapular skinfold thickness (P<0.05). After adjustment for 2-h blood glucose levels during the first OGTT, subscapular skinfold thickness remained significantly associated with persistent IGT (odds ratio 1.84; P<0.05). In addition to the 2-h blood glucose level, subscapular skinfold thickness was the best predictor of persistent IGT, suggesting that adding simple anthropometric measures to oral glucose tolerance testing may improve the distinction between persistent and transient glucose intolerance.

Glucose Tolerance and Cardiovascular Risk in Young Adult African Americans

Patients with type 2 diabetes have higher rates of cardiovascular events. Among African Americans, there is a higher prevalence of both cardiovascular disease and type 2 diabetes. Few studies have examined longitudinally the change in glucose tolerance in younger adult African Americans. To examine the longitudinal relationship of glucose tolerance with other cardiovascular risk factors, 30 African American men and women aged 20 to 43 years were examined twice at an interval of 4 to 5 years. Cardiovascular risk factors, glucose tolerance, and insulin sensitivity (determined from euglycemic hyperinsulinemic clamp procedure) were assessed at each examination. Known diabetics were excluded from initial enrollment. The relationship of glucose tolerance status (normal, impaired, or diabetic glucose tolerance) to body mass index, blood pressure, cholesterol, and insulin sensitivity were further investigated. Initial oral glucose tolerance test identified 24 of 130 (18.5%) subjects with impaired glucose tolerance and 2 of 130 (1.5%) subjects with diabetes. Of the remaining 104 subjects with normal glucose tolerance, subsequent 5-year examination detected 31 (29.8%) with impaired glucose tolerance and 5 (4.8%) with diabetes. Those who later developed diabetes had higher mean systolic blood pressure (133 versus 121, P = 0.037) at exam 1. By exam 2, those with abnormal glucose tolerance had worse cardiovascular risk profiles and increased insulin resistance (P < 0.001). Conversion to abnormal glucose tolerance is relatively frequent in young adult African Americans. Deterioration in glucose tolerance may be preceded by higher systolic blood pressure and is accompanied by worsening of other cardiovascular risk factors and insulin resistance.

Admission plasma glucose and diabetes mellitus in elderly admissions to hospital.

Over 6 months, all admissions to three geriatric wards were studied to define an admission plasma glucose level (APG) that identified previously undiagnosed diabetes mellitus. Subjects with APG> or =7.0 mmol l(-1) had a modified oral glucose tolerance test (OGTT) when well before discharge if their dose of steroid and/or thiazide was constant, and they were neither terminally ill nor dead; excluded were 1 subject on reducing steroid doses, and 9 moribund admissions without APG. If the first 2 h OGTT result was > or =11.1 mmol l(-1), a second OGTT was performed 6 weeks later to fulfil 1985 WHO criteria. Subjects with APG<7.0 mmol l(-1) did not have OGTT. Seventy had a previous diagnosis of diabetes; scrutiny of records and OGTT refuted the diagnosis in 5, who were excluded from further analysis. Diabetes was only commonly found among those with APG> or =8.0 mmol l(-1), and the proportion was small until APG> or =13 mmol l(-1), although even then only 47% (95% CI 21-73%) had diabetes. Fourteen of 28 subjects with initial OGTT results suggesting diabetes were not diabetic on retesting. Inpatient mortality was higher if APG> or =7.0 (Odds ratio 2.82; CI 1.63-4.89) or the subject had known diabetes (Odds ratio 2.43; CI 1.15-4.97) compared to APG<7; there was no age or sex difference between these three groups. We conclude that, unless overtly diabetic, diagnosis of diabetes in elderly medical admissions needs later confirmation.

Insulin deficiency and increased plasma concentration of intact and 32/33 split proinsulin in subjects with impaired glucose tolerance.

In order to determine insulin status and beta cell function during the oral glucose tolerance test (OGTT), in impaired glucose tolerance (IGT), 51 such subjects and matched controls, identified during a population survey for diabetes, underwent a 75 g OGTT. Fasting, 30 min and 2 h insulin and intact proinsulin, and fasting and 2 h 32/33 split proinsulin, were measured by specific two-site immunoradiometric assays. The subjects with IGT had higher fasting (geometric mean +/- SD, 5.0 +/- 4.0 pmol-1 vs 2.9 +/- 1.7, p < 0.02) and 2 h intact proinsulin (23 +/- 14 vs 14 +/- 12, p < 0.0001), and fasting (3.2 +/- 3 pmol-1 vs 1.8 +/- 1.8, p < 0.0007) and 2 h 32/33 split proinsulin (18.3 +/- 19 pmol-1 vs 6.6 +/- 15, p < 0.0001). Despite higher plasma glucose concentrations, the IGT group had similar fasting insulin, lower 30 min insulin (216 +/- 124 pmol-1 vs 278 +/- 130, p < 0.02), and a lower 30 min insulin/glucose ratio (23.7 +/- 2.1 vs 34.8 +/- 2.3, p < 0.002). The percentage of fasting proinsulin-like to total insulin-like molecules was higher in those with IGT (15.3 +/- 8% vs 11.6 +/- 8, p < 0.04). After 6 months, at repeat OGTT, the same subjects with IGT were classified as 'persisters' or 'reverters'. The persister (24/51 47.1%), at initial OGTT, had a higher 2 h glucose level, a greater BMI and higher systolic blood pressure, but other parameters were similar to the reverters.(ABSTRACT TRUNCATED AT 250 WORDS)

Vitamin D Improves Oral Glucose Tolerance and Insulin Secretion in Human Diabetes.

Glucose intolerance and impaired insulin secretion in vitamin D deficiency, and altered vitamin D metabolism in streptozotocin- or alloxan-induced diabetes, are well established in experimental animals. No such data are available in humans. The present study was conducted on a group of uncontrolled diabetic patients: those with non-insulin-dependent diabetes mellitus (NIDDM: 42) and those with insulin-dependent diabetes mellitus (IDDM: 6). After an initial oral glucose tolerance test, each subject was given one intramuscular injection of vitamin D (vitamin D3: 300, 000IU), and the oral glucose tolerance test was then repeated after 4 weeks. Administration of vitamin D resulted in a significant improvement in the oral glucose tolerance, serum calcium, and also glucose-stimulated increase in serum insulin levels. Possible mechanism(s) of this beneficial effect of vitamin D on human diabetes is discussed.

Study in Tanzania of Impaired Glucose Tolerance: Methodological Myth?

During a study of diabetes prevalence in six rural Tanzanian communities, a repeat oral glucose tolerance test (OGTT) was carried out in 514 subjects greater than or equal to 15 yr of age within 1 wk of an initial 75-g OGTT. In 498 subjects, blood glucose was measured 2 h after the glucose load on both occasions, and in 175 subjects, fasting blood glucose measurement was also repeated. Of the 498 subjects, 245 had normal glucose tolerance in the first test and were selected at random for further testing; 223 subjects had impaired glucose tolerance (IGT), and 30 had diabetic values. Diabetes and IGT were diagnosed on the basis of the 2-h blood glucose values. In the second test, 241 (98.4%) of the 245 subjects with normal tolerance continued in this category and 4 (1.6%) showed IGT. Of the 223 with IGT in the first test, 171 (76.2%) reverted to normal on the second test, 7 (3.1%) had diabetic values, and 45 (20.2%) persisted with IGT. Of the 30 subjects diagnosed as diabetic in the first test, 8 (26.7%) remained with diabetic values, 11 (36.7%) had IGT, and 11 (36.7%) were normal. Based on the second test, the population-prevalence rates of diabetes and IGT would have been 0.5 and 3.3% vs. 1 and 7.6% based on the first test. There was a significant downward trend in the mean 2-h blood glucose values in all three diagnostic groups. Regression toward the mean could not account for the downward shift in blood glucose values observed on retesting.(ABSTRACT TRUNCATED AT 250 WORDS)

Diabetes mellitus in a young man with Bloom's syndrome

Bloom's syndrome (BS) is a rare autosomal recessive genetic disorder in which diabetes mellitus unusually frequently develops as a complication. We report on a 21-year-old Japanese male patient with BS who exhibited impaired glucose tolerance (IGT) in the initial oral glucose tolerance test (OGTT) and had developed patterns of diabetes mellitus by the second OGTT at the 2-years-and-2-months follow-up. German and Passarge reported that the onset of diabetes in patients with BS was in late adolescence or early adulthood. Our results support the findings of German and Passarge. Therefore, when a person with BS reaches late adolescence or early adulthood, an OGTT is necessary to ascertain whether the patient has IGT or diabetes mellitus as a complication, regardless of whether or not diabetic signs such as glucosuria are present.