The effect of glucose tolerance test on fetoplacental circulation.

OBJECTIVE: Acute hyperglycemia affects the fetoplacental circulation. This study aims to investigate the possible effect of acute hyperglycemia induced by 50 g oral glucose tolerance test (OGTT) on fetoplacental circulation in women between 24 and 28 weeks of gestation. MATERIALS AND METHODS: Between January 2019 and April 2019, a total of 29 women who were between 24 and 28 weeks of gestation with a singleton gestation and were in low-risk group were included in this prospective study. All patients underwent fetal biometric measurements using ultrasonography (USG) and were administered 50 g OGTT. Before and 1 h after the test, Doppler USG was used to measure uterine artery, umbilical artery (UA), middle cerebral artery (MCA), pulsatility index (PI), resistance index (RI), and systolic/diastolic (S/D) ratio. The cerebroplacental ratio (CPR) was calculated as the ratio of the MCA-PI/UA-PI. RESULTS: There was a decline in the MCA-RI (p = 0.008) and UA-PI (p = 0.021) at 1 h after the administration of 50 g OGTT. Z-scores of the mean UA-PI, MCA-PI, and CPR were calculated and a statistically significant increase in the Z-scores of the mean UA-PI was observed (p = 0.028). CONCLUSION: Our study results show that acute hyperglycemia induced by OGTT significantly increases the Z-scores of the UA-PI, affecting the fetoplacental circulation.

The effect of 75-g oral glucose tolerance test on maternal and foetal Doppler parameters in healthy pregnancies: a cross-sectional observational study.

Hyperglycaemia can alter placental resistance to blood flow and hyperglycaemia has adverse perinatal outcomes. Oral glucose tolerance testing (OGTT) increases the maternal plasma glucose levels temporarily and mimics metabolic hyperglycaemia. The blood flow of the uterine artery (UtA), umbilical artery (UA), middle cerebral artery (MCA) were assessed before, 1 and 2 h following the OGTT by using Doppler ultrasonography. Z-score of cerebroplacental ratio (CPR), pulsatility index (PI) for three vessels were evaluated separately. All measurements of the MCA, UA, UtA Doppler parameters were not statistically different for fasting, and 1 and 2 h following the 75 g OGTT in the 53 pregnant women with a singleton gestation in the low-risk group. This study results show that acute hyperglycaemia induced by OGTT has no effect on maternal and foetal Doppler parameters in healthy pregnancies.IMPACT STATEMENTWhat is already known on this subject? Foetal glucose is affected by maternal blood glucose concentrations and placental blood flow. Acute hyperglycaemia may have an effect on maternal, and foetal Doppler parameters among healthy pregnanciesWhat do the results of this study add? Our findings indicate that blood flow velocity metric measurements in the UA, MCA and UtA were not affected by the OGTT in healthy pregnant women.What are the implications of these findings for clinical practice and/or further research? Acute hyperglycaemia induced by OGTT does not have any effect on fetomaternal circulation, especially foetal brain blood flow. Other foetal vessels including ductus venosus, renal artery, etc. may be affected by maternal blood glucose levels during the OGTT or in diabetic patients. Future prospective studies consisting of diabetic patients are warranted to verify the exact effect of glucose levels on foetal and maternal circulation.

Is biochemical hypoglycemia necessary during an insulin tolerance test?

Objective The insulin tolerance test (ITT) has been accepted as the gold standard test for assessing the integrity of the growth hormone (GH) - insulin-like growth factor (IGF-1) axis and the hypothalamic-pituitary-adrenal (HPA) axis. The goal of the test is to achieve clinical and biochemical hypoglycemia at a blood glucose level ≤ 40 mg/dL to effectively and correctly assess the HPA and GH-IGF-1 axes. In this study, the GH and cortisol responses of patients who achieved and failed to achieve biochemical hypoglycemia during an ITT were compared. Subjects and methods One hundred thirty-five patients with pituitary disorders were included in the study. Samples for blood glucose levels were obtained after clear symptoms of clinical hypoglycemia developed. The patients were enrolled in the hypoglycemic and nonhypoglycemic groups according to whether their plasma glucose level ≤ 40 mg/dL or > 40 mg/dL during an ITT, and the groups were compared in terms of their GH and cortisol responses. Results The mean age, body mass index and waist circumference of the two patient groups were found to be similar. The mean blood glucose level was significantly lower in the hypoglycemic group than in the nonhypoglycemic group (19.3 and 52.0 mg/dL, respectively). When the two groups were compared in terms of peak cortisol and GH responses, no statistically significant differences were found. Conclusion The data presented suggest that clinically symptomatic hypoglycemia is as effective as biochemically confirmed hypoglycemia during an ITT. Arch Endocrinol Metab. 2020;64(1):82-8.

Is biochemical hypoglycemia necessary during an insulin tolerance test?

ABSTRACT Objective The insulin tolerance test (ITT) has been accepted as the gold standard test for assessing the integrity of the growth hormone (GH) - insulin-like growth factor (IGF-1) axis and the hypothalamic-pituitary-adrenal (HPA) axis. The goal of the test is to achieve clinical and biochemical hypoglycemia at a blood glucose level ≤ 40 mg/dL to effectively and correctly assess the HPA and GH-IGF-1 axes. In this study, the GH and cortisol responses of patients who achieved and failed to achieve biochemical hypoglycemia during an ITT were compared. Subjects and methods One hundred thirty-five patients with pituitary disorders were included in the study. Samples for blood glucose levels were obtained after clear symptoms of clinical hypoglycemia developed. The patients were enrolled in the hypoglycemic and nonhypoglycemic groups according to whether their plasma glucose level ≤ 40 mg/dL or > 40 mg/dL during an ITT, and the groups were compared in terms of their GH and cortisol responses. Results The mean age, body mass index and waist circumference of the two patient groups were found to be similar. The mean blood glucose level was significantly lower in the hypoglycemic group than in the nonhypoglycemic group (19.3 and 52.0 mg/dL, respectively). When the two groups were compared in terms of peak cortisol and GH responses, no statistically significant differences were found. Conclusion The data presented suggest that clinically symptomatic hypoglycemia is as effective as biochemically confirmed hypoglycemia during an ITT. Arch Endocrinol Metab. 2020;64(1):82-8

The effect of hyperglycemic peak induced by oral glucose tolerance test on the oxidant and antioxidant levels

Background/aim: The possibility of adverse effects of the oral glucose tolerance test (OGTT) carried out for the screening of gestational diabetes among pregnant women and fetuses is a frequently discussed topic. The purpose of this study was to investigate the effects of the hyperglycemia peak during OGTT on the levels of oxidants and antioxidants in the body. Materials and methods: Eighty individuals who applied to the Outpatient Clinic with suspected diabetes and OGTT indication were included in the study. Glucose, total oxidant capacity status (TOS), total antioxidant capacity (TAS), superoxide dismutase (SOD), and lipid hydroperoxide (LOOH) levels were tested on blood samples collected from these individuals at 0, 60, and 120 min during the OGTT carried out with 75 g of glucose. Oxidative stress index (OSI) was calculated as the ratio of TOS to TAS. Results: While the oxidative parameters TOS and LOOH were significantly increased at 60. min of OGTT, only LOOH was significantly increased at 120. min of OGTT. Significant decreases in antioxidative parameters (TAS, SOD) were observed at 60. and 120. min of the OGTT and OSI was significantly increased at 60. and 120. min of the OGTT. Conclusion: Oxidative stress parameters were increased and antioxidative parameters were decreased during the OGTT. However, more extended studies are required to determine the effects of the increased oxidative stress on pregnant women and fetuses.

Impaired glucose metabolism is associated with tooth loss in middle-aged adults: The Northern Finland Birth Cohort Study 1966.

AIM: We investigated the association of impaired glucose metabolism with tooth loss in adults in the Northern Finland Birth Cohort Study 1966 (NFBC1966). METHODS: We examined 4394 participants from the 46-year follow-up of the NFBC1966. Self-reported number of teeth as well as insulin and glucose values, taken during a standard oral glucose tolerance test (OGTT), served as the primary study variables. A multinomial logistic regression model served to analyse (unadjusted, smoking-adjusted and fully adjusted) the association between number of teeth (0-24, 25-27, 28-32) and glucose metabolism in women and men. RESULTS: Among women, type 2 diabetes - whether previously known or detected during screening - pointed to a higher likelihood of 0-24 teeth (fully adjusted OR = 2.99, 95%CI = 1.54-5.80) and 25-27 teeth (OR = 1.91, 95%CI = 1.18-3.08) than did normal glucose tolerance. Similarly, impaired fasting glucose and impaired glucose tolerance together indicated a higher likelihood of 0-24 teeth (OR = 1.71, 95%CI = 1.09-2.69) than did normal glucose tolerance. A similar, statistically non-significant, pattern emerged among men. Number of teeth associated with OGTT insulin and glucose curves as well as with the Matsuda index in both women and men. CONCLUSIONS: Tooth loss strongly associated with impaired glucose metabolism in middle-aged Finnish women.

Efficacy and pharmacokinetics of subcutaneous exendin (9-39) in patients with post-bariatric hypoglycaemia.

AIM: To evaluate the efficacy, pharmacokinetic (PK) profile and tolerability of subcutaneous (s.c.). exendin 9-39 (Ex-9) injection in patients with post-bariatric hypoglycaemia (PBH). METHODS: Nine women who had recurrent symptomatic hypoglycaemia after undergoing Roux-en-Y gastric bypass were enrolled in this 2-part, single-blind, single-ascending-dose study. In Part 1, a single participant underwent equimolar low-dose intravenous (i.v.) vs s.c. Ex-9 administration; in Part 2, 8 participants were administered single ascending doses of s.c. Ex-9 during an oral glucose tolerance test (OGTT). Glycaemic, hormonal, PK and symptomatic responses were compared with those obtained during the baseline OGTT. RESULTS: Although an exposure-response relationship was observed, all doses effectively prevented hyperinsulinaemic hypoglycaemia and improved associated symptoms. On average, the postprandial glucose nadir was increased by 66%, peak insulin was reduced by 57%, and neuroglycopenic symptoms were reduced by 80%. All doses were well tolerated with no treatment-emergent adverse events observed. CONCLUSIONS: Injection s.c. of Ex-9 appears to represent a safe, effective and targeted therapeutic approach for treatment of PBH. Further investigation involving multiple doses with chronic dosing is warranted.

The assessment of the serum C-peptide and plasma glucose levels by orally administered whey proteins in type 2 diabetes mellitus.

A personalized antidiabetic therapy is not yet part of the official guidelines of professional societies for clinical practice. The aim of this study was to evaluate the serum C-peptide and plasma glucose levels in patients with type 2 diabetes mellitus (T2DM) after oral administration of whey proteins. Sixteen overweight T2DM Caucasians with good glycemic control and with preserved fasting serum C-peptide levels (>200 nmol/l) were enrolled in this study. Two oral stimulation tests - one with 75 g of glucose (OGTT) and the other with 75 g of whey proteins (OWIST) - were administered for assessing serum C-peptide and plasma glucose levels in each participant. Both oral tests induced similar pattern of C-peptide secretion, with a peak at 90 min. The serum C-peptide peak concentration was 2.91+/-0.27 nmol/l in OWIST, which was 22 % lower than in OGTT. Similarly, the C-peptide iAUC(0-180) were 32 % lower in the OWIST than in the OGTT (p<0.01). Contrary to OGTT the OWIST did not cause a significant increase of glycemia (p<0.01). Our study showed that the OWIST represents a useful tool in estimation of stimulated serum C-peptide levels in patients with T2DM.

Screening for gestational diabetes mellitus based on different risk profiles and settings for improving maternal and infant health.

BACKGROUND: Gestational diabetes mellitus (GDM) is a form of diabetes that occurs in pregnancy. Although GDM usually resolves following birth, it is associated with significant morbidities for mothers and their infants in the short and long term. There is strong evidence to support treatment for GDM. However, there is uncertainty as to whether or not screening all pregnant women for GDM will improve maternal and infant health and if so, the most appropriate setting for screening. This review updates a Cochrane Review, first published in 2010, and subsequently updated in 2014. OBJECTIVES: To assess the effects of screening for gestational diabetes mellitus based on different risk profiles and settings on maternal and infant outcomes. SEARCH METHODS: We searched Cochrane Pregnancy and Childbirth's Trials Register (31 January 2017), ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform (ICTRP) (14 June 2017), and reference lists of retrieved studies. SELECTION CRITERIA: We included randomised and quasi-randomised trials evaluating the effects of different protocols, guidelines or programmes for screening for GDM based on different risk profiles and settings, compared with the absence of screening, or compared with other protocols, guidelines or programmes for screening. We planned to include trials published as abstracts only and cluster-randomised trials, but we did not identify any. Cross-over trials are not eligible for inclusion in this review. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed study eligibility, extracted data and assessed the risk of bias of the included trials. We resolved disagreements through discussion or through consulting a third reviewer. MAIN RESULTS: We included two trials that randomised 4523 women and their infants. Both trials were conducted in Ireland. One trial (which quasi-randomised 3742 women, and analysed 3152 women) compared universal screening versus risk factor-based screening, and one trial (which randomised 781 women, and analysed 690 women) compared primary care screening versus secondary care screening. We were not able to perform meta-analyses due to the different interventions and comparisons assessed.Overall, there was moderate to high risk of bias due to one trial being quasi-randomised, inadequate blinding, and incomplete outcome data in both trials. We used GRADEpro GDT software to assess the quality of the evidence for selected outcomes for the mother and her child. Evidence was downgraded for study design limitations and imprecision of effect estimates. Universal screening versus risk-factor screening (one trial) MotherMore women were diagnosed with GDM in the universal screening group than in the risk-factor screening group (risk ratio (RR) 1.85, 95% confidence interval (CI) 1.12 to 3.04; participants = 3152; low-quality evidence). There were no data reported under this comparison for other maternal outcomes including hypertensive disorders of pregnancy, caesarean birth, perineal trauma, gestational weight gain, postnatal depression, and type 2 diabetes. ChildNeonatal outcomes: large-for-gestational age, perinatal mortality, mortality or morbidity composite, hypoglycaemia; and childhood/adulthood outcomes: adiposity, type 2 diabetes, and neurosensory disability, were not reported under this comparison. Primary care screening versus secondary care screening (one trial) MotherThere was no clear difference between the primary care and secondary care screening groups for GDM (RR 0.91, 95% CI 0.50 to 1.66; participants = 690; low-quality evidence), hypertension (RR 1.41, 95% CI 0.77 to 2.59; participants = 690; low-quality evidence), pre-eclampsia (RR 0.80, 95% CI 0.36 to 1.78; participants = 690;low-quality evidence), or caesarean section birth (RR 1.00, 95% CI 0.80 to 1.27; participants = 690; low-quality evidence). There were no data reported for perineal trauma, gestational weight gain, postnatal depression, or type 2 diabetes. ChildThere was no clear difference between the primary care and secondary care screening groups for large-for-gestational age (RR 1.37, 95% CI 0.96 to 1.96; participants = 690; low-quality evidence), neonatal complications: composite outcome, including: hypoglycaemia, respiratory distress, need for phototherapy, birth trauma, shoulder dystocia, five minute Apgar less than seven at one or five minutes, prematurity (RR 0.99, 95% CI 0.57 to 1.71; participants = 690; low-quality evidence), or neonatal hypoglycaemia (RR 1.10, 95% CI 0.28 to 4.38; participants = 690; very low-quality evidence). There was one perinatal death in the primary care screening group and two in the secondary care screening group (RR 1.10, 95% CI 0.10 to 12.12; participants = 690; very low-quality evidence). There were no data for neurosensory disability, or childhood/adulthood adiposity or type 2 diabetes. AUTHORS' CONCLUSIONS: There are insufficient randomised controlled trial data evaluating the effects of screening for GDM based on different risk profiles and settings on maternal and infant outcomes. Low-quality evidence suggests universal screening compared with risk factor-based screening leads to more women being diagnosed with GDM. Low to very low-quality evidence suggests no clear differences between primary care and secondary care screening, for outcomes: GDM, hypertension, pre-eclampsia, caesarean birth, large-for-gestational age, neonatal complications composite, and hypoglycaemia.Further, high-quality randomised controlled trials are needed to assess the value of screening for GDM, which may compare different protocols, guidelines or programmes for screening (based on different risk profiles and settings), with the absence of screening, or with other protocols, guidelines or programmes. There is a need for future trials to be sufficiently powered to detect important differences in short- and long-term maternal and infant outcomes, such as those important outcomes pre-specified in this review. As only a proportion of women will be diagnosed with GDM in these trials, large sample sizes may be required.

Plasma but not serum brain-derived neurotrophic factor concentration is decreased by oral glucose tolerance test-induced hyperglycemia in children.

BACKGROUND: Little is known regarding the relationships among circulating brain-derived neurotrophic factor (BDNF) levels and glucose or insulin in children and adolescents. The objective of this study was to investigate whether circulating BDNF levels would change during the oral glucose tolerance test (OGTT). METHODS: We performed the OGTT and measured the serial changes in BDNF levels in both plasma and serum. RESULTS: There were 22 subjects in the normal type (N) group and 20 in the borderline/diabetic type (B/D) group, defined by the results of the OGTT. Serum levels of BDNF were almost five times higher and plasma levels gradually decreased during the OGTT, whereas serum levels showed no significant change. The reduction of plasma BDNF level changes from baseline to 120 min were significantly different between the N and B/D groups (36.3% vs. 20.8%, p=0.023). CONCLUSIONS: Our results showed that plasma levels of BDNF are more sensitive to acute changes in glucose or insulin levels than serum.

Adverse effects during the oral glucose tolerance test in post-bariatric surgery patients

ABSTRACT Objective The oral glucose tolerance test (OGTT) is used in the screening of gestational diabetes, in diagnosis of type 2 diabetes in conjunction with fasting blood glucose and glycated hemoglobin. The aim of this study was to examine the incidence and risk factors of adverse effects of OGTT in patients who underwent bariatric surgery, in addition to proposing standardization for ordering the OGTT in these patients. Subjects and methods This study assessed the incidence of adverse effects in 128 post-bariatric surgery patients who underwent the OGTT. Descriptive and logistic regression analysis were performed, the dependent variables were defined as the presence of signs (tremor, profuse sweating, tachycardia), symptoms (nausea, diarrhea, dizziness, weakness), and hypoglycemia (blood glucose ≤ 50 mg/dL). Results One hundred and seventeen participants (91.4%) were female; 38 (29.7%) participants were pregnant. High incidence (64.8%) of adverse effects was observed: nausea (38.4%), dizziness (30.5%), weakness (25.8%), diarrhea (23.4%), hypoglycemia (14.8%), tachycardia (14.1%), tremor (13.3%), profuse sweating (12.5%) and one case of severe hypoglycemia (24 mg/dL). The presence of signs was associated with hypoglycemia (OR = 8.1, CI 95% 2.6-25.1). The arterial hypertension persisted as a risk factor for the incidence of signs (OR = 3.6, CI 95% 1.2-11.3). Fasting glucose below 75 mg/dL increased the risk of hypoglycemia during the test (OR = 9.5, CI 95% 2.6-35.1). Conclusion In this study, high incidence of adverse effects during the OGTT was observed in post-bariatric surgery patients. If these results are confirmed by further studies, the indication and regulation of the OGTT procedure must be reviewed for these patients.

Effect of Intravenous Glucose Tolerance Test on Bone Turnover Markers in Adults with Normal Glucose Tolerance.

BACKGROUND It is well known that enteral nutrients result in acute suppression of bone turnover markers (BTMs), and incretin hormones are believed to play a significant role in this physiological skeletal response. However, there is limited research exploring the impact of parenteral nutrients on BTMs. Our aim was to assess the influence of intravenous glucose on BTMs in adults with normal glucose tolerance (NGT). MATERIAL AND METHODS We conducted 1-h intravenous glucose tolerance test (IVGTT) in 24 subjects with NGT. Blood samples were collected before and 5, 10, 15, 20, 30, 60 min after administration of glucose, then serum levels of bone formation marker procollagen type I N-terminal propeptide (P1NP) and resorption marker C-terminal cross-linking telopeptides of collagen type I (CTX) were measured. RESULTS During IVGTT, the fasting CTX level fell gradually and reached a nadir of 80.4% of the basal value at 60 min. Conversely, the fasting P1NP level decreased mildly and reached a nadir of 90.6% of the basal value at 15 min, then gradually increased and reached 96.6% at 60 min. The CTX-to-P1NP ratio increased slightly and reached a peak of 104.3% of the basal value at 10 min, then fell gradually and reached a nadir of 83% at 60 min. CONCLUSIONS Our study indicates that intravenous glucose results in an acute suppression of BTMs in the absence of incretin hormones. The mechanism responsible for this needs further investigation.

Adverse effects during the oral glucose tolerance test in post-bariatric surgery patients.

OBJECTIVE: The oral glucose tolerance test (OGTT) is used in the screening of gestational diabetes, in diagnosis of type 2 diabetes in conjunction with fasting blood glucose and glycated hemoglobin. The aim of this study was to examine the incidence and risk factors of adverse effects of OGTT in patients who underwent bariatric surgery, in addition to proposing standardization for ordering the OGTT in these patients. SUBJECTS AND METHODS: This study assessed the incidence of adverse effects in 128 post-bariatric surgery patients who underwent the OGTT. Descriptive and logistic regression analysis were performed, the dependent variables were defined as the presence of signs (tremor, profuse sweating, tachycardia), symptoms (nausea, diarrhea, dizziness, weakness), and hypoglycemia (blood glucose ≤ 50 mg/dL). RESULTS: One hundred and seventeen participants (91.4%) were female; 38 (29.7%) participants were pregnant. High incidence (64.8%) of adverse effects was observed: nausea (38.4%), dizziness (30.5%), weakness (25.8%), diarrhea (23.4%), hypoglycemia (14.8%), tachycardia (14.1%), tremor (13.3%), profuse sweating (12.5%) and one case of severe hypoglycemia (24 mg/dL). The presence of signs was associated with hypoglycemia (OR = 8.1, CI 95% 2.6-25.1). The arterial hypertension persisted as a risk factor for the incidence of signs (OR = 3.6, CI 95% 1.2-11.3). Fasting glucose below 75 mg/dL increased the risk of hypoglycemia during the test (OR = 9.5, CI 95% 2.6-35.1). CONCLUSION: In this study, high incidence of adverse effects during the OGTT was observed in post-bariatric surgery patients. If these results are confirmed by further studies, the indication and regulation of the OGTT procedure must be reviewed for these patients.

Effect of Short-term Intensive Insulin Therapy on Post-challenge Hyperglucagonemia in Early Type 2 Diabetes.

CONTEXT: Hyperglucagonemia is a characteristic feature of type 2 diabetes (T2DM) that has been postulated to be due to ß-cell dysfunction and the resultant loss of insulin-mediated α-cell suppression. When administered in early T2DM, short-term intensive insulin therapy (IIT) can improve ß-cell function, resulting in reduced glycemic variability. OBJECTIVE: To evaluate the impact of IIT on hyperglucagonemia and its associations with ß-cell function and glycemic variability. Design/Setting/Participants/Intervention: Sixty-two patients with T2DM of mean 3.0 ± 2.1 years duration and glycated hemoglobin of 6.8 ± 0.7% underwent 4 weeks of IIT, consisting of basal detemir and premeal insulin aspart. MAIN OUTCOME MEASURES: Glucagon response was measured by area under the glucagon curve (AUCglucagon) on oral glucose tolerance test at baseline and 1 day post-IIT. ß-Cell function before and after IIT was assessed by Insulin Secretion-Sensitivity Index-2 and ΔISR0-120/Δglucose0-120*Matsuda index (where ISR is the prehepatic insulin secretion rate determined by C-peptide deconvolution). Glucose variability was assessed in both the first and last weeks by the coefficient of variation of capillary glucose on daily six-point self-monitoring profiles. RESULTS: Both Insulin Secretion-Sensitivity Index-2 and ΔISR0-120/Δglucose0-120*Matsuda index demonstrated improvement in ß-cell function after IIT (both P ≤ .02), accompanied by reduced glycemic variability (P = .05). There was a marked reduction in AUCglucagon after IIT, as compared to baseline (P < .001). However, the decrease in AUCglucagon was not associated with the change in either ß-cell measure (both P ≥ .34) or glucose variability (P = .37). CONCLUSIONS: Short-term IIT can reduce post-challenge hyperglucagonemia in early T2DM, but this effect does not appear to be due to improved ß-cell function.

Safety and specificity of the growth hormone suppression test in patients with diabetes.

The purpose of this study was to evaluate the safety of the oral glucose tolerance test (OGTT) and its capacity to suppress growth hormone (GH) in diabetic patients without acromegaly. A total of 135 diabetic patients submitted to the OGTT for GH suppression were studied. The following selection criteria were applied: age between 20 and 70 years; body mass index≥18.5 and ≤27 kg/m2; absence of kidney, liver, or thyroid disease; no use of estrogens, androgens, corticosteroids, or levothyroxine. Adequate suppression of GH was defined as a nadir below the cut-off established for a sample of 200 normoglycemic subjects (<0.25 µg/L for men, <0.74 µg/L for premenopausal women, and <0.5 µg/L for postmenopausal women). Acromegaly was diagnosed in five patients. Among the 130 diabetic patients without known pituitary disease or a clinical suspicion of acromegaly, 95.5% of men, 94% of premenopausal women, and 96.6% of postmenopausal women presented adequate GH suppression (vs 97.5% of normoglycemic controls). In all patients without acromegaly, the lowest GH levels (nadir) were achieved after the administration of glucose and not during baseline measurement. None of the patients had acute complications [ketoacidosis, hyperosmolar state, and symptomatic marked hyperglycemia (>300 mg/dL)] on the day of the test and up to 3 days thereafter. We demonstrated the safety of the OGTT and its capacity to suppress GH in diabetic patients without acromegaly. In addition, we suggest the adoption of a protocol to prevent possible risks of the OGTT in patients with diabetes.

Screening and subsequent management for gestational diabetes for improving maternal and infant health.

BACKGROUND: Gestational diabetes mellitus (GDM) is a form of diabetes that occurs in pregnancy. Although GDM usually resolves following birth, it is associated with significant morbidities for mother and baby both perinatally and in the long term. There is strong evidence to support treatment for GDM. However, there is little consensus on whether or not screening for GDM will improve maternal and infant health and if so, the most appropriate protocol to follow. OBJECTIVES: To assess the effects of different methods of screening for GDM and maternal and infant outcomes. SEARCH METHODS: We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (1 December 2013). SELECTION CRITERIA: Randomised and quasi-randomised trials evaluating the effects of different methods of screening for GDM. DATA COLLECTION AND ANALYSIS: Two review authors independently conducted data extraction and quality assessment. We resolved disagreements through discussion or through a third author. MAIN RESULTS: We included four trials involving 3972 women in the review. One quasi-randomised trial compared risk factor screening with universal or routine screening by 50 g oral glucose challenge testing. Women in the universal screening group were more likely to be diagnosed with GDM (one trial, 3152 women, risk ratio (RR) 0.44, 95% confidence interval (CI) 0.26 to 0.75). This trial did not report on the other primary outcomes of the review (positive screen for GDM, mode of birth, large-for-gestational age, or macrosomia). Considering secondary outcomes, infants of mothers in the risk factor screening group were born marginally earlier than infants of mothers in the routine screening group (one trial, 3152 women, mean difference (MD) -0.15 weeks, 95% CI -0.27 to -0.03).The remaining three trials evaluated different methods of administering a 50 g glucose load. Two small trials compared glucose monomer with glucose polymer testing, with one of these trials including a candy bar group. One trial compared a glucose solution with food. No differences in diagnosis of GDM were found between each comparison. However, in one trial significantly more women in the glucose monomer group screened positive for GDM than women in the candy bar group (80 women, RR 3.49, 95% CI 1.05 to 11.57). The three trials did not report on the primary review outcomes of mode of birth, large-for-gestational age or macrosomia. Overall, women drinking the glucose monomer experienced fewer side effects from testing than women drinking the glucose polymer (two trials, 151 women, RR 2.80, 95% CI 1.10 to 7.13). However, we observed substantial heterogeneity between the trials for this result (I² = 61%). AUTHORS' CONCLUSIONS: There was insufficient evidence to determine if screening for gestational diabetes, or what types of screening, can improve maternal and infant health outcomes.