The artificial pancreas: two alternative approaches to achieve a fully closed-loop system with optimal glucose control

INTRODUCTION

Diabetes mellitus type 1 is a chronic disease that implies mandatory external insulin delivery. The patients must monitor their blood glucose levels and administer appropriate insulin boluses to keep their blood glucose within the desired range. It requires a lot of time and endeavour, and many patients struggle with suboptimal glucose control despite all their efforts.

MATERIALS AND METHODS

This narrative review combines existing knowledge with new discoveries from animal experiments.

DISCUSSION

In the last decade, artificial pancreas (AP) devices have been developed to improve glucose control and relieve patients of the constant burden of managing their disease. However, a feasible and fully automated AP is yet to be developed. The main challenges preventing the development of a true, subcutaneous (SC) AP system are the slow dynamics of SC glucose sensing and particularly the delay in effect on glucose levels after SC insulin infusions. We have previously published studies on using the intraperitoneal space for an AP; however, we further propose a novel and potentially disruptive way to utilize the vasodilative properties of glucagon in SC AP systems.

CONCLUSION

This narrative review presents two lesser-explored viable solutions for AP systems and discusses the potential for improvement toward a fully automated system: A) using the intraperitoneal approach for more rapid insulin absorption, and B) besides using glucagon to treat and prevent hypoglycemia, also administering micro-boluses of glucagon to increase the local SC blood flow, thereby accelerating SC insulin absorption and SC glucose sensor site dynamics.

Effects of Low-Dose Glucagon on Subcutaneous Insulin Absorption in Pigs

Background

Slow insulin absorption prevents the development of a fully automated artificial pancreas with subcutaneous insulin delivery.

Objective

We have hypothesized that glucagon could be used as a vasodilator to accelerate insulin absorption in a bihormonal subcutaneous artificial pancreas. The present proof-of-concept study is the first study to investigate the pharmacokinetics of insulin after subcutaneous administration of a low dose of glucagon at the site of subcutaneous insulin injection.

Methods

Twelve anesthetized pigs were randomized to receive a subcutaneous injection of 10 IU insulin aspart with either 100 µg glucagon or the equivalent volume of placebo (0.9% saline solution) injected at the same site. Arterial samples were collected for 180 minutes to determine insulin, glucagon, and glucose concentrations.

Results

Glucagon did not influence the insulin concentration Tmax in plasma. The plasma insulin AUC0-∞ was significantly larger after glucagon administration (P < 0.01). The glucagon group had significantly higher glucose concentrations in the first 30 minutes after insulin administration (P < 0.05).

Conclusions

This proof-of-concept study indicates that glucagon may increase the total absorption of a single dose of subcutaneously injected insulin. This is a novel observation. However, we did not observe any reduction in insulin concentration Tmax, as we had hypothesized. Further, glucagon induced a significant, undesirable increase in early blood glucose concentrations.

Vasodilatory effects of glucagon: A possible new approach to enhanced subcutaneous insulin absorption in artificial pancreas devices

Patients with diabetes mellitus type 1 depend on exogenous insulin to keep their blood glucose concentrations within the desired range. Subcutaneous bihormonal artificial pancreas devices that can measure glucose concentrations continuously and autonomously calculate and deliver insulin and glucagon infusions is a promising new treatment option for these patients. The slow absorption rate of insulin from subcutaneous tissue is perhaps the most important factor preventing the development of a fully automated artificial pancreas using subcutaneous insulin delivery. Subcutaneous insulin absorption is influenced by several factors, among which local subcutaneous blood flow is one of the most prominent. We have discovered that micro-doses of glucagon may cause a substantial increase in local subcutaneous blood flow. This paper discusses how the local vasodilative effects of micro-doses of glucagon might be utilised to improve the performance of subcutaneous bihormonal artificial pancreas devices. We map out the early stages of our hypothesis as a disruptive novel approach, where we propose to use glucagon as a vasodilator to accelerate the absorption of meal boluses of insulin, besides using it conventionally to treat hypoglycaemia.

Pharmacokinetics of glucagon after intravenous, intraperitoneal and subcutaneous administration in a pig model

Introduction

There is increasing scientific evidence to substantiate using low‐dose glucagon as a supplement to insulin therapy in artificial pancreata for diabetes mellitus type 1. The delivery of both these hormones intraperitoneally would mimic normal physiology. However, our knowledge of the pharmacological properties of glucagon after intraperitoneal administration is limited. This study compared the pharmacokinetics of glucagon after intraperitoneal, subcutaneous and intravenous administration and the pharmacodynamic effects of glucagon on glucose metabolism after intraperitoneal and subcutaneous administration in a pig model.

Materials and methods

Twelve pigs were included. Glucagon was administered intraperitoneally, subcutaneously and intravenously in a randomised order. Arterial samples were collected every 2–10 min for 150 min to determine plasma glucagon and blood glucose concentrations.

Results

The bioavailability of glucagon was significantly lower after intraperitoneal compared with subcutaneous administration with a median difference (95% confidence interval) of 13% (4–22). The effect of glucagon on glucose metabolism was equal after intraperitoneal and subcutaneous administration.

Conclusions

Intraperitoneal glucagon administration resulted in lower systemic glucagon exposure than subcutaneous administration without loss of efficiency. We interpret this as evidence of a major first‐pass metabolism of glucagon in the liver.

Maternal PCOS status and metformin in pregnancy: Steroid hormones in 5-10 years old children from the PregMet randomized controlled study

Objective

Polycystic ovary syndrome (PCOS) is a common endocrine disorder, with potential effects on offspring both genetically and through altered intrauterine environment. Metformin, which ameliorate hormonal disturbances in non-pregnant women with PCOS is increasingly used in pregnancy. It passes the placenta, and the evidence on potential consequences for offspring endocrine development is scarce. We explore the potential effects of maternal PCOS status and intrauterine metformin exposure on offspring steroid hormone levels.

Design

This is a follow-up study of 5–10 years old children from the PregMet-study–a randomized controlled trial comparing metformin (2000 mg/day) to placebo during PCOS pregnancies. Of the 255 children invited, 117 (46%) were included.

Methods

There was no intervention in this follow-up study. Outcomes were serum levels of androstenedione, testosterone, SHBG, cortisol, 17-hydroxyprogesterone, 11-deoxycortisol and calculated free testosterone converted to gender-and age adjusted z-scores from a Norwegian reference population. These were compared in i) placebo-exposed children versus children from the reference population (z-score zero) by the deviation in z-score by one-sample t-tests and ii) metformin versus placebo-exposed children by two-sample t-tests. Holm-Bonferroni adjustments were performed to account for multiple endpoints.

Results

Girls of mothers with PCOS (n = 30) had higher mean z-scores of androstenedione (0.73 (95% confidence interval (CI) 0.41 to 1.06), p<0.0001), testosterone (0.76 (0.51 to 1.00), p<0.0001), and free testosterone (0.99 (0.67 to 1.32), p<0.0001) than the reference population. Metformin-exposed boys (n = 31) tended to have higher 11-deoxycortisol z-score than placebo-exposed boys (n = 24) (mean difference 0.65 (95% CI 0.14–1.17), p = 0.014).

Conclusion

Maternal PCOS status was associated with elevated androgens in 5- to 10-year-old daughters, which might indicate earlier maturation and increased risk of developing PCOS. An impact of metformin in pregnancy on steroidogenesis in children born to mothers with PCOS cannot be excluded. Our findings need confirmation in studies that include participants that have entered puberty.

Physiological effects of intraperitoneal versus subcutaneous insulin infusion in patients with diabetes mellitus type 1: A systematic review and meta-analysis

The intraperitoneal route of administration accounts for less than 1% of insulin treatment regimes in patients with diabetes mellitus type 1 (DM1). Despite being used for decades, a systematic review of various physiological effects of this route of insulin administration is lacking. Thus, the aim of this systematic review was to identify the physiological effects of continuous intraperitoneal insulin infusion (CIPII) compared to those of continuous subcutaneous insulin infusion (CSII) in patients with DM1. Four databases (EMBASE, PubMed, Scopus and CENTRAL) were searched beginning from the inception date of each database to 10^th of July 2020, using search terms related to intraperitoneal and subcutaneous insulin administration. Only studies comparing CIPII treatment (≥ 1 month) with CSII treatment were included. Primary outcomes were long-term glycaemic control (after ≥ 3 months of CIPII inferred from glycated haemoglobin (HbA1c) levels) and short-term (≥ 1 day for each intervention) measurements of insulin dynamics in the systematic circulation. Secondary outcomes included all reported parameters other than the primary outcomes. The search identified a total of 2242 records; 39 reports from 32 studies met the eligibility criteria. This meta-analysis focused on the most relevant clinical end points; the mean difference (MD) in HbA1c levels during CIPII was significantly lower than during CSII (MD = -6.7 mmol/mol, [95% CI: -10.3 –-3.1]; in percentage: MD = -0.61%, [95% CI: -0.94 –- 0.28], p = 0.0002), whereas fasting blood glucose levels were similar (MD = 0.20 mmol/L, [95% CI: -0.34–0.74], p = 0.47; in mg/dL: MD = 3.6 mg/dL, [95% CI: -6.1–13.3], p = 0.47). The frequencies of severe hypo- and hyper-glycaemia were reduced. The fasting insulin levels were significantly lower during CIPII than during CSII (MD = 16.70 pmol/L, [95% CI: -23.62 –-9.77], p < 0.0001). Compared to CSII treatment, CIPII treatment improved overall glucose control and reduced fasting insulin levels in patients with DM1.

Intraperitoneal insulin administration in pigs: effect on circulating insulin and glucose levels

INTRODUCTION

The effect of intraperitoneal insulin infusion has limited evidence in the literature. Therefore, the aim of the study was to investigate the pharmacokinetics and pharmacodynamics of different intraperitoneal insulin boluses. There is a lack of studies comparing the insulin appearance in the systemic circulation after intraperitoneal compared with subcutaneous insulin delivery. Thus, we also aimed for a comparison with the subcutaneous route.

RESEARCH DESIGN AND METHODS

Eight anesthetized, non-diabetic pigs were given three different intraperitoneal insulin boluses (2, 5 and 10 U). The order of boluses for the last six pigs was randomized. Endogenous insulin and glucagon release were suppressed by repeated somatostatin analog injections. The first pig was used to identify the infusion rate of glucose to maintain stable glucose values throughout the experiment. The estimated difference between insulin boluses was compared using two-way analysis of variance (GraphPad Prism V.8).In addition, a trial of three pigs which received subcutaneous insulin boluses was included for comparison with intraperitoneal insulin boluses.

RESULTS

Decreased mean blood glucose levels were observed after 5 and 10 U intraperitoneal insulin boluses compared with the 2 U boluses. No changes in circulating insulin levels were observed after the 2 and 5 U intraperitoneal boluses, while increased circulating insulin levels were observed after the 10 U intraperitoneal boluses. Subcutaneously injected insulin resulted in higher values of circulating insulin compared with the corresponding intraperitoneal boluses.

CONCLUSIONS

Smaller intraperitoneal boluses of insulin have an effect on circulating glucose levels without increasing insulin levels in the systemic circulation. By increasing the insulin bolus, a major increase in circulating insulin was observed, with a minor additive effect on circulating glucose levels. This is compatible with a close to 100% first-pass effect in the liver after smaller intraperitoneal boluses. Subcutaneous insulin boluses markedly increased circulating insulin levels.

Intraperitoneal and subcutaneous glucagon delivery in anaesthetized pigs: effects on circulating glucagon and glucose levels

Glucagon is a pancreatic hormone and increases the blood glucose levels. It may be incorporated in a dual hormone artificial pancreas, a device to automatically and continuously control blood glucose levels of individuals with diabetes. Artificial pancreas systems have been developed for use in the subcutaneous tissue; however, the systems are not fully automated due to slow dynamics. The intraperitoneal space is therefore investigated as an alternative location for an artificial pancreas. Glucose dynamics after subcutaneous and intraperitoneal glucagon delivery in ten anaesthetized pigs were investigated. The pigs received intraperitoneal boluses of 0.3 µg/kg and 0.6 µg/kg and a subcutaneous bolus of 0.6 µg/kg in randomized order. They also received an intraperitoneal bolus of 1 mg given at the end of the experiments to test the remaining capacity of rapid glucose release. Six pigs were included in the statistical analysis. The intraperitoneal glucagon bolus of 0.6 µg/kg gave a significantly higher glucose response from 14 to 30 min compared with the subcutaneous bolus. The results indicate that glucagon induces a larger glucose response after intraperitoneal delivery compared with subcutaneous delivery and is encouraging for the incorporation of glucagon in an intraperitoneal artificial pancreas.

Feasibility of Early Meal Detection Based on Abdominal Sound

In classical approaches for an artificial pancreas, continuous glucose monitoring (CGM) is the only measured variable used for insulin dosing and additional control functions. The CGM values are subject to time delays and slow dynamics between blood and the sensing location. These time lags compromise the controller's performance in maintaining (near to) normal glucose levels. Meal information could enhance the control outcome. However, meal announcement by the user is not reliable, and it takes 30 min to 40 min from meal onset until a meal is detected by methods based on CGM. In this pilot study, the use of bowel sounds for meal detection was investigated. In particular, we focused on whether bowel sounds change qualitatively during or shortly after meal ingestion. After fasting for at least 4 h, 11 healthy volunteers ingested a lunch meal at their usual time. Abdominal sound was recorded by a condenser microphone that was attached to the right upper quadrant of the abdomen by medical tape. Features that describe the power distribution over the frequency spectrum were extracted and used for classification by support vector machines. These classifiers were trained in a leave-one-out cross-validation scheme. Meals could be detected on average 10 min (std: 4.4 min) after they had started. Half of these were detected without false alarms. This shows that abdominal sound monitoring could provide an early meal detection. Further studies should investigate this possibility on a larger population in more general settings.

Validity of the FINDRISC as a prediction tool for diabetes in a contemporary Norwegian population: a 10-year follow-up of the HUNT study

OBJECTIVE

The Finnish Diabetes Risk Score (FINDRISC) is a recommended tool for type 2 diabetes prediction. There is a lack of studies examining the performance of the current 0-26 point FINDRISC scale. We examined the validity of FINDRISC in a contemporary Norwegian risk environment.

RESEARCH DESIGN AND METHODS

We followed 47 804 participants without known diabetes and aged ≥20 years in the HUNT3 survey (2006-2008) by linkage to information on glucose-lowering drug dispensing in the Norwegian Prescription Database (2004-2016). We estimated the C-statistic, sensitivity and specificity of FINDRISC as predictor of incident diabetes, as indicated by incident use of glucose-lowering drugs. We estimated the 10-year cumulative diabetes incidence by categories of FINDRISC.

RESULTS

The C-statistic (95% CI) of FINDRISC in predicting future diabetes was 0.77 (0.76 to 0.78). FINDRISC ≥15 (the conventional cut-off value) had a sensitivity of 38% and a specificity of 90%. The 10-year cumulative diabetes incidence (95% CI) was 4.0% (3.8% to 4.2%) in the entire study population, 13.5% (12.5% to 14.5%) for people with FINDRISC ≥15 and 2.8% (2.6% to 3.0%) for people with FINDRISC <15. Thus, FINDRISC ≥15 had a positive predictive value of 13.5% and a negative predictive value of 97.2% for diabetes within the next 10 years. To approach a similar sensitivity as in the study in which FINDRISC was developed, we would have to lower the cut-off value for elevated FINDRISC to ≥11. This would yield a sensitivity of 73%, specificity of 67%, positive predictive value of 7.7% and negative predictive value of 98.5%.

CONCLUSIONS

The validity of FINDRISC and the risk of diabetes among people with FINDRISC ≥15 is substantially lower in the contemporary Norwegian population than assumed in official guidelines. To identify ~3/4 of those developing diabetes within the next 10 years, we would have to lower the threshold for elevated FINDRISC to ≥11, which would label ~1/3 of the entire adult population as having an elevated FINDRISC necessitating a glycemia assessment.

Disulfiram repurposing combined with nutritional copper supplement as add-on to chemotherapy in recurrent glioblastoma (DIRECT): Study protocol for a randomized controlled trial

Background: Disulfiram (DSF) is a well-tolerated, inexpensive, generic drug that has been in use to treat alcoholism since the 1950s. There is now independent preclinical data that supports DSF as an anticancer agent, and experimental data suggest that copper may increase its anti-neoplastic properties. There is also some clinical evidence that DSF is a promising anticancer agent in extracranial cancers. In glioblastoma, DSF induced O 6-methylguanine methyltransferase (MGMT) inhibition may increase response to alkylating chemotherapy. A recent phase I study demonstrated the safety of DSF in glioblastoma patients when DSF was administered at doses below 500 mg/day together with chemotherapy. We plan to assess the effects of DSF combined with nutritional copper supplement (DSF-Cu) as an adjuvant to alkylating chemotherapy in glioblastoma treatment. Methods: In an academic, industry independent, multicenter, open label randomized controlled phase II/III trial with parallel group design (1:1) we will assess the efficacy and safety of DSF-Cu in glioblastoma treatment. The study will include 142 patients at the time of first recurrence of glioblastoma where salvage therapy with alkylating chemotherapy is planned. Patients will be randomized to treatment with or without DSF-Cu. Primary end-point is survival at 6 months. Secondary end-points are overall survival, progression free survival, quality of life, contrast enhancing tumor volume and safety. Discussion: There is a need to improve the treatment of recurrent glioblastoma. Results from this randomized controlled trial with DSF-Cu in glioblastoma will serve as preliminary evidence of the future role of DSF-Cu in glioblastoma treatment and a basis for design and power estimations of future studies. In this publication we provide rationale for our choices and discuss methodological issues. Trial registration: The study underwent registration in EudraCT 2016-000167-16 (Date: 30.03.2016,) and Clinicaltrials.gov NCT02678975 (Date: 31.01.2016) before initiating the study.

Basic lifestyle advice to individuals at high risk of type 2 diabetes: a 2-year population-based diabetes prevention study. The DE-PLAN intervention in the HUNT Study, Norway

OBJECTIVE

Among individuals at high risk for diabetes identified through a population survey, we performed an intervention study with basic lifestyle advice aiming to prevent diabetes.

RESEARCH DESIGN AND METHODS

Among 50 806 participants in the HUNT3 Survey (2006-2008), 5297 individuals with Finnish Diabetes Risc Score (FINDRISC ≥15 were invited to an oral glucose tolerance test (OGTT) and an education session with lifestyle advice, and 2634 (49.7%) attended. Among them, 2380 people without diabetes were included in the prevention study with repeated examinations and education sessions after 6, 12, and 24 months. We examined participation, diabetes incidence, glycemia, and adiposity during follow-up.

RESULTS

Of 2380 participants, 1212 (50.9%) participated in ≥3 of the four examinations. Diabetes was detected in 3.5%, 3.1%, and 4.0% of individuals at the 6-month, 12-month, and 24-month examinations, respectively, indicating a 10.3% 2-year diabetes incidence. Mean (95% CI) increases from baseline to 2-year follow-up were 0.30 (0.29 to 0.32) percentage points (3.3 (3.2 to 3.5) mmol/mol) for Hemoglobin A_1c, 0.13 (0.10 to 0.16) mmol/L for fasting serum-glucose, 0.46 (0.36 to 0.56) mmol/L for 2-hour OGTT s-glucose, 0.30 (0.19 to 0.40) kg/m² forbody mass index (BMI) (all p<0.001) and -0.5 (-0.9 to -0.2) cm for waist circumference (p=0.004), with broadly similar estimates by baseline age, sex, education, depressive symptoms, BMI, physical activity, and family history of diabetes. Only 206 (8.7%) participants had evidence of >5% weight loss during follow-up; their fasting and 2-hour s-glucose did not increase, and HbA_1c increased less than in other participants.

CONCLUSION

Basic lifestyle advice given to high-risk individuals during three group sessions with 6-month intervals was not effective in reducing 2-year diabetes risk.

Intraperitoneal, subcutaneous and intravenous glucagon delivery and subsequent glucose response in rats: a randomized controlled crossover trial

OBJECTIVE

Hypoglycemia is a frequent and potentially dangerous event among patients with diabetes mellitus type 1. Subcutaneous glucagon is an emergency treatment to counteract severe hypoglycemia. The effect of intraperitoneal glucagon delivery is sparsely studied. We performed a direct comparison of the blood glucose response following intraperitoneally, subcutaneously and intravenously administered glucagon.

RESEARCH DESIGN AND METHODS

This is a prospective, randomized, controlled, open-label, crossover trial in 20 octreotide-treated rats. Three interventions, 1  week apart, in a randomized order, were done in each rat. All 20 rats were given intraperitoneal and subcutaneous glucagon injections, from which 5 rats were given intravenous glucagon injections and 15 rats received placebo (intraperitoneal isotonic saline) injection. The dose of glucagon was 5 µg/kg body weight for all routes of administration. Blood glucose levels were measured before and until 60 min after the glucagon/placebo injections.

RESULTS

Compared with placebo-treated rats, a significant increase in blood glucose was observed 4 min after intraperitoneal glucagon administration (p=0.009), whereas after subcutaneous and intravenous glucagon administration significant increases were seen after 8 min (p=0.002  and p<0.001, respectively). In intraperitoneally treated compared with subcutaneously treated rats, the increase in blood glucose was higher after 4 min (p=0.019) and lower after 40 min (p=0.005) and 50 min (p=0.011). The maximum glucose response occurred earlier after intraperitoneal compared with subcutaneous glucagon injection (25 min vs 35 min; p=0.003).

CONCLUSIONS

Glucagon administered intraperitoneally gives a faster glucose response compared with subcutaneously administered glucagon in rats. If repeatable in humans, the more rapid glucose response may be of importance in a dual-hormone artificial pancreas using the intraperitoneal route for administration of insulin and glucagon.

A Review of the Current Challenges Associated with the Development of an Artificial Pancreas by a Double Subcutaneous Approach

INTRODUCTION

Patients with diabetes type 1 (DM1) struggle daily to achieve good glucose control. The last decade has seen a rush of research groups working towards an artificial pancreas (AP) through the application of a double subcutaneous approach, i.e., subcutaneous (SC) continuous glucose monitoring (CGM) and continuous subcutaneous insulin infusion. Few have focused on the fundamental limitations of this approach, especially regarding outcome measures beyond time in range.

METHODS

Based on insulin physiology, the limitations of CGM, SC insulin absorption, meal challenge, and physical activity in DM1 patients, we discuss the limitations of the double SC approach. Finally, we discuss safety measures and the achievements reported in some recent AP studies that have utilized the double SC approach.

RESULTS

Most studies show that a double SC AP increases the time in range compared to a sensor-augmented insulin pump and shortens the time in hypoglycemia. Despite these achievements, the proportion of time spent in hyperglycemia is still roughly 20-40%, and hypoglycemia is still present 1-4% of the time. The main factors limiting further progress are the latency of SC CGM (at least 5-10 min) and the slow pharmacokinetics of SC-delivered fast-acting insulin. The maximum blood insulin level is reached after 45 min and the maximum glucose-lowering effect is observed after 1.5-2 h, while the glucose-lowering effect lasts for at least 5 h.

CONCLUSIONS

Although using a double SC AP leads to significant improvements in glucose control, the SC approach has severe limitations that hamper further progress towards a robust AP.

Preoperative octreotide therapy and surgery in acromegaly: associations between glucose homeostasis and treatment response

In acromegaly, high GH/IGF-1 levels associate with abnormal glucose metabolism. Somatostatin analogs (SSAs) reduce GH and IGF-1 but inhibit insulin secretion. We studied glucose homeostasis in de novo patients with acromegaly and changes in glucose metabolism after treatment with SSA and surgery. In this post hoc analysis from a randomized controlled trial, 55 de novo patients with acromegaly, not using antidiabetic medication, were included. Before surgery, 26 patients received SSAs for 6 months. HbA1c, fasting glucose, and oral glucose tolerance test were performed at baseline, after SSA pretreatment and at 3 months postoperative. Area under curve of glucose (AUC-G) was calculated. Glucose homeostasis was compared to baseline levels of GH and IGF-1, change after SSA pretreatment, and remission both after SSA pretreatment and 3 months postoperative. In de novo patients, IGF-1/GH levels did not associate with baseline glucose parameters. After SSA pretreatment, changes in GH/IGF-1 correlated positively to change in HbA1c levels (both p < 0.03). HbA1c, fasting glucose, and AUC-G increased significantly during SSA pretreatment in patients not achieving hormonal control (all p < 0.05) but did not change significantly in patients with normalized hormone levels. At 3 months postoperative, HbA1c, fasting glucose, and AUC-G were significantly reduced in both cured and not cured patients (all p < 0.05). To conclude, in de novo patients with acromegaly, disease activity did not correlate with glucose homeostasis. Surgical treatment of acromegaly improved glucose metabolism in both cured and not cured patients, while SSA pretreatment led to deterioration in glucose homeostasis in patients not achieving biochemical control.

Hemoglobin A1c as screening for gestational diabetes mellitus in Nordic Caucasian women

BACKGROUND

Gestational diabetes mellitus (GDM) increases the risk for preeclampsia and macrosomia. GDM is conventionally diagnosed by an oral glucose tolerance test (OGTT). Hemoglobin A1c (HbA1c) is a marker for the average glucose level the last 2-3 months. We aimed to study if HbA1c alone or in combination with patient characteristics can be used to screen for GDM and reduce the number of OGTTs, and whether it could predict preeclampsia or birth weight.

METHODS

855 women from a previous study on the effect of exercise on GDM prevalence were eligible, whereof 677 were included. GDM was diagnosed by WHO 1999 criteria (GDM-WHO) and modified IADPSG criteria (GDM-IADPSG), at pregnancy weeks 18-22 and 32-36. HbA1c analyzed at pregnancy weeks 18-22 and 32-36, variables from patient history and clinical examination were considered for logistic regression models. The diagnostic accuracy was assessed by ROC curve analysis.

RESULTS

Accumulated GDM prevalence was 6.7 % by WHO and 7.2 % by modified IADPSG criteria. Nearly a third could potentially have avoided an OGTT by using HbA1c to exclude GDM-IADPSG with a sensitivity of 88 % at week 18-22 and 97 % at week 32-36. Further, 16 % could have avoided an OGTT with a sensitivity of 96 % using HbA1c at week 18-22 to exclude GDM-IADPSG throughout pregnancy. HbA1c was not accurate at diagnosing GDM-IADPSG, and it was inaccurate at screening for GDM-WHO at any time point. Adding other predictors did not increase the number of potentially avoidable OGTTs significantly. HbA1c was not significantly associated with preeclampsia or birth weight.

CONCLUSIONS

HbA1c could potentially reduce the number of OGTTs.

HbA1c as screening for gestational diabetes mellitus in women with polycystic ovary syndrome

BACKGROUND

Gestational diabetes mellitus (GDM) is associated with adverse pregnancy outcomes such as preeclampsia and macrosomia. Women with polycystic ovary syndrome (PCOS) are at increased risk of developing GDM. Today, GDM is diagnosed by oral glucose tolerance test (OGTT), a rather cumbersome test for the women and health care system. The objectives of this study were to investigate whether HbA1c in first trimester of pregnancy could be used as a screening test for GDM in first trimester and throughout pregnancy in order to reduce the number of OGTTs, and whether it could predict preeclampsia and macrosomia in women with PCOS.

METHODS

Post hoc analyses of data from 228 women from a prospective, randomised, multicenter study comparing metformin to placebo from first trimester to delivery. Fasting and 2-h plasma glucose were measured during a 75 g OGTT in first trimester, gestational week 19 and 32 as well as fasting plasma glucose in gestational week 36. GDM was diagnosed by WHO criteria from 1999 in first trimester and throughout pregnancy and by modified IADPSG criteria (i.e. lacking the 1-h plasma glucose value) in first trimester. The diagnostic accuracy was assessed by logistic regression and ROC curve analysis.

RESULTS

The area under the ROC curve for first trimester HbA1c for screening of GDM diagnosed by WHO criteria in first trimester was 0.60 (95 % CI 0.44-0.75) and 0.56 (95 % CI 0.47-0.65) for GDM diagnosed throughout pregnancy. Only 2.2 % (95 % CI 0.7-5.1 %) of the participants could have avoided OGTT. HbA1c was not statistically significantly associated with GDM diagnosed by modified IADPSG criteria in first trimester. However, first trimester HbA1c was statistically significantly associated with preeclampsia. Both HbA1c and GDM by WHO criteria in first trimester, but not by IADPSG, were negatively associated with birth weight.

CONCLUSION

First trimester HbA1c can not be used to exclude or predict GDM in women with PCOS, but it might be better to predict preeclampsia than the GDM diagnosis.

Using the likelihood ratio to evaluate allowable total error – an example with glycated hemoglobin (HbA1c)

Allowable total error is derived in many ways, often from data on biological variation in normal individuals. We present a new principle for evaluating allowable total error: What are the diagnostic consequences of allowable total errors in terms of errors in likelihood ratio (LR)? Glycated hemoglobin A

We estimated a function for LR of HbA

Measuring HbA

These principles of evaluating allowable total error can be applied to any diagnostically used analyte where the distribution of the analyte’s concentration is known in patients with and without the disease in a clinically relevant population. In the example used, the allowable total error of 6% leads to very erroneous LRs, suggesting that the NGSP limits of ±6% are too liberal.

The effect of exercise and metformin treatment on circulating free DNA in pregnancy

INTRODUCTION

Some pregnancy complications are characterized by increased levels of cell-free fetal (cffDNA) and maternal DNA (cfmDNA), the latter may also be elevated during physical strain. This study aims at assessing the impact of exercise and metformin intervention in pregnancy, and to compare the levels of cell free DNA in pregnant women with or without PCOS diagnosis.

METHODS

Consecutive women from two previous randomized controlled trials in pregnancy were included. Women came from a trial with organized exercise vs. standard antenatal care in pregnancy and a trial of metformin vs. placebo in PCOS women. Levels of cffDNA, cfmDNA and cell-free total DNA (cftDNA) were measured by qPCR.

RESULTS

Training in pregnancy did not affect the levels of cffDNA, cfmDNA or cftDNA. PCOS-women treated with metformin had lower levels of cfmDNA and cftDNA at week 32 (mean ± SD: 301 ± 162 versus 570 ± 337, p = 0.012, 345 ± 173 versus 635 ± 370, p = 0.019); otherwise the levels were comparable to PCOS-controls. Metformin-treated PCOS-women had higher cffDNA at inclusion, in the 1st trimester; later on in pregnancy the levels in the metformin and placebo groups were equal. A comparison of pregnant women in the exercise study (TRIP) to placebo-treated pregnant PCOS-women, showed the levels of cffDNA, cfmDNA or cftDNA during mid-pregnancy (weeks 18-36) to be equal.

DISCUSSION

Training during pregnancy was not associated with altered levels of cffDNA cfmDNA or cftDNA, but metformin treatment may reduce cfmDNA and cftDNA in pregnant PCOS women.

Preoperative octreotide treatment of acromegaly: long-term results of a randomised controlled trial

OBJECTIVE

Randomised studies have demonstrated a beneficial effect of pre-surgical treatment with somatostatin analogues (SSA) in acromegaly when evaluated early postoperatively. The objective of this study was to evaluate the long-term surgical cure rates.

METHODS

Newly diagnosed patients were randomised to direct surgery (n=30) or 6-month pretreatment with octreotide LAR (n=32). The patients were evaluated 1 and 5 years postoperatively. Cure was defined as normal IGF1 levels and by normal IGF1 level combined with nadir GH <2 mU/l in an oral glucose tolerance test, all without additional post-operative treatment. A meta-analysis using the other published randomised study with long-term analyses on preoperative SSA treatment was performed.

RESULTS

The proportion of patients receiving post-operative acromegaly treatment was equal in the two groups. When using the combined criteria for cure, 10/26 (38%) macroadenomas were cured in the pretreatment group compared with 6/25 (24%) in the direct surgery group 1 year postoperatively (P=0.27), and 9/22 (41%) vs 6/22 (27%) macroadenomas, respectively, 5 years postoperatively (P=0.34). In the meta-analysis, 16/45 (36%) macroadenomas were cured using combined criteria in the pretreatment group vs 8/45 (18%) in the direct surgery group after 6-12 months (P=0.06), and 15/41 (37%) vs 8/42 (19%), respectively, in the long-term (P=0.08).

CONCLUSION

This study does not prove a beneficial effect of SSA pre-surgical treatment, but in the meta-analysis a trend towards significance can be claimed. A potential favourable, clinically relevant response cannot be excluded.

Gestational diabetes mellitus among Norwegian women with polycystic ovary syndrome: prevalence and risk factors according to the WHO and the modified IADPSG criteria

OBJECTIVE

The consequences of the recently proposed International Association of Diabetes in Pregnancy Study Group (IADPSG) criteria for gestational diabetes mellitus (GDM) in women with polycystic ovary syndrome (PCOS) are not known. We compared the prevalence rates and risk factors for GDM in PCOS women according to both the WHO and the modified IADPSG criteria.

DESIGN

Post hoc analyses from a randomized, multicenter study were used.

METHODS

Fasting and 2-h plasma glucose levels were measured using a 75 g oral glucose tolerance test. GDM was diagnosed according to both the WHO and the modified IADPSG criteria.

RESULTS

The prevalence rates of GDM according to the WHO and the modified IADPSG criteria were 9.2 and 15.0% at week 12, 18.7 and 18.7% at week 19, and 25.6 and 24.2% at week 32. Shorter stature and increased insulin levels were correlated with WHO-GDM, but not with modified IADPSG-GDM at weeks 12 and 19. Less weight gain in pregnancy predicted GDM according to both sets of criteria. GDM diagnosis was correlated with less maternal weight loss the first year post-partum.

CONCLUSIONS

No difference was found in the prevalence of GDM between the two sets of criteria used. Less weight gain in pregnancy was associated with GDM, independent of the diagnostic criteria used. Reduced weight loss the first year post-partum in women with GDM raises the question of whether GDM diagnosis per se or the fact that these women lose less weight after pregnancy predicts later diabetes mellitus.

Short-term continuous glucose monitoring: effects on glucose and treatment satisfaction in patients with type 1 diabetes mellitus; a randomized controlled trial

Objective:  To assess whether 4 week's use of a continuous glucose monitoring (CGM) system improves glucose control, treatment satisfaction or health status, as compared to intensified conventional finger-prick measurements (ICFM) in patients with type 1 diabetes mellitus (DM1). Method:  Thirty patients suffering from DM1 for more than three years and treated with either insulin pumps or multiple daily insulin injections, were included in a randomised controlled cross-over trial. They were Caucasians of both genders, between 18 and 50 years, and had moderately well controlled diabetes. The participants performed either ICFM or CGM for 4 weeks, followed by an 8 week's observation period. Thereafter they were crossed over to the opposite intervention. HbA(1c) , hypoglycaemic episodes, treatment satisfaction and health status were assessed at all meetings, although HbA(1c) was the primary endpoint. Results:  At inclusion mean HbA(1c) was 7.8 ± 0.9 %. The mean change in HbA(1c) was -0.2 ± 0.1% and -0.2 ± 0.1% for the CGM and the ICFM periods, accordingly (p = 0.91). The mean changes in HbA(1c) during the combined treatment and observation periods were -0.1 ± 0.1% and -0.2 ± 0.1% for the CGM and the ICFM period, accordingly (p = 0.86). The frequency of severe hypoglycaemic episodes, treatment satisfaction and health status was also equal between the two interventions. No adverse events were observed.

Use of metformin before and during assisted reproductive technology in non-obese young infertile women with polycystic ovary syndrome: a prospective, randomized, double-blind, multi-centre study

BACKGROUND

To study the effect of metformin before and during assisted reproductive technology (ART) on the clinical pregnancy rate (CPR) in non-obese women with polycystic ovary syndrome (PCOS).

METHODS

A multi-centre, prospective, randomized, double-blind study was conducted in eight IVF clinics in four Nordic countries. We enrolled 150 PCOS women with a body mass index <28 kg/m(2), and treated them with 2000 mg/day metformin or identical placebo tablets for ≥ 12 weeks prior to and during long protocol IVF or ICSI and until the day of pregnancy testing. The primary outcome measure was CPR. Secondary outcome measures included spontaneous pregnancy rates during the pretreatment period, and the live birth rate (LBR).

RESULTS

Among IVF treated women (n = 112), biochemical pregnancy rates were identical in both groups (42.9%), and there were no significant differences in the metformin versus the placebo group in CPR [39.3 versus 30.4%; 95% confidence interval (CI): -8.6 to 26.5]. The LBR was 37.5 versus 28.6% (95% CI: -8.4 to 26.3). However, prior to IVF there were 15 (20.3%) spontaneous pregnancies in the metformin group and eight (10.7%) in the placebo group (95% CI: -1.9 to 21.1; P = 0.1047). According to intention to treat analyses (n = 149); significantly higher overall CPR were observed in the metformin versus placebo group (50.0 versus 33.3%; 95% CI: -1.1 to 32.3; P = 0.0391). LBR was also significantly higher with use of metformin versus placebo (48.6 versus 32.0; 95% CI: 1.1 to 32.2; P = 0.0383). No major unexpected safety issues or multiple births were reported. More gastrointestinal side effects occurred in the metformin group (41 versus 12%; 95% CI: 0.15 to 0.42; P < 0.001).

CONCLUSIONS

Metformin treatment for 12 weeks before and during IVF or ICSI in non-obese women with PCOS significantly increases pregnancy and LBRs compared with placebo. However, there was no effect on the outcome of ART per se.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT00159575.

Metformin versus placebo from first trimester to delivery in polycystic ovary syndrome: a randomized, controlled multicenter study

CONTEXT

Metformin is widely prescribed to pregnant women with polycystic ovary syndrome (PCOS) in an attempt to reduce pregnancy complications. Metformin is not approved for this indication, and evidence for this practice is lacking.

OBJECTIVES

Our objective was to test the hypothesis that metformin, from first trimester to delivery, reduces pregnancy complications in women with PCOS.

DESIGN AND SETTING

We conducted a randomized, placebo-controlled, double-blind, multicenter study at 11 secondary care centers.

PARTICIPANTS

The participants were 257 women with PCOS, in the first trimester of pregnancy, aged 18-42 yr.

INTERVENTION

We randomly assigned 274 singleton pregnancies (in 257 women) to receive metformin or placebo, from first trimester to delivery.

MAIN OUTCOME MEASURES

The prevalence of preeclampsia, gestational diabetes mellitus, preterm delivery, and a composite of these three outcomes is reported.

RESULTS

Preeclampsia prevalence was 7.4% in the metformin group and 3.7% in the placebo group (3.7%; 95% CI, -1.7-9.2) (P=0.18). Preterm delivery prevalence was 3.7% in the metformin group and 8.2% in the placebo group (-4.4%; 95%, CI, -10.1-1.2) (P=0.12). Gestational diabetes mellitus prevalence was 17.6% in the metformin group and 16.9% in the placebo group (0.8%; 95% CI, -8.6-10.2) (P=0.87). The composite primary endpoint prevalence was 25.9 and 24.4%, respectively (1.5%; 95% CI, -8.9-11.3) (P=0.78). Women in the metformin group gained less weight during pregnancy compared with those in the placebo group. There was no difference in fetal birth weight between the groups.

CONCLUSIONS

Metformin treatment from first trimester to delivery did not reduce pregnancy complications in PCOS.

Metformin has no major effects on glucose homeostasis in pregnant women with PCOS: results of a randomized double-blind study

OBJECTIVE

Previous non-randomized and uncontrolled studies indicate major metformin effects on glucose homeostasis in pregnant women with polycystic ovary syndrome (PCOS). We investigated metformin effects on glucose homeostasis in a prospective controlled study.

MATERIAL AND METHODS

Forty pregnant women with PCOS and without known diabetes mellitus were included in the first trimester and randomized to either metformin 850 mg twice daily or placebo. Outcome measures were fasting glucose and insulin at inclusion and changes to pregnancy weeks 19, 32 and 36 and 2 h glucose levels during a 75 g oral glucose tolerance test (OGTT) carried out at inclusion and pregnancy weeks 19 and 32. Insulin resistance (HOMA-IR) and beta-cell function (HOMA-beta) were calculated using the homeostasis assessment model.

RESULTS

At inclusion, 2 h glucose levels during OGTT were higher in the placebo group (7.14 versus 6.03 mmol/L; p = 0.012). Accordingly, 6 out of 22 in the metformin group versus 2 out of 18 women in the placebo group (p = 0.21) had gestational diabetes mellitus at inclusion. At gestational weeks 19 and 32, 2-h plasma glucose levels were equal between the groups. The total proportion of women with gestational diabetes did not differ between the groups, nor did any of the other indices of glucose metabolism and insulin resistance.

CONCLUSIONS

Metformin seems to be without major effects on glucose homeostasis in pregnant women with PCOS.

Metformin treatment in pregnant women with polycystic ovary syndrome--is reduced complication rate mediated by changes in the uteroplacental circulation?

OBJECTIVES

To study a possible effect of metformin on the uteroplacental circulation.

METHODS

Forty pregnant women with polycystic ovary syndrome (PCOS) were enrolled in a randomized, double-blind, placebo-controlled trial of metformin (1700 mg/day) during pregnancy. Doppler ultrasound examinations of the uterine arteries were performed at 12, 19, 24, 32 and 36 gestational weeks and of the umbilical artery at 19, 24, 32 and 36 gestational weeks.

RESULTS

There was a greater mean bilateral uterine artery pulsatility index (PI) at 12 weeks (1.95 vs. 1.58, P = 0.02), and a greater reduction in mean PI from 12 to 19 weeks (P = 0.03) in metformin-treated women. There were no differences in mean PI values between groups at 19, 24, 32 or 36 gestational weeks. Pregnancy complications, such as preterm delivery before 32 weeks, severe pre-eclampsia or serious postpartum events, occurred only in the placebo group (7 of 22 vs. 0 of 18, P = 0.01). There were no associations between uterine artery Doppler measurements and pregnancy complications. We found no differences between groups in mean umbilical artery PI at 19, 24, 32 or 36 gestational weeks.

CONCLUSIONS

In this small randomized trial, metformin treatment in pregnancy reduced uterine artery impedance between 12 and 19 weeks of gestation, and this was associated with reduced complication rate. Published by John Wiley & Sons, Ltd.

Maternal testosterone levels during pregnancy are associated with offspring size at birth

OBJECTIVE

Animal studies have indicated that maternal androgen levels influence the intrauterine environment and development of the offspring. Human data are missing. We therefore investigated the possible association between maternal androgens and offspring size at birth in humans.

DESIGN

A random sample of parous Caucasian women (n=147) was followed prospectively through pregnancy.

METHODS

Maternal serum levels of dehydroepiandrosterone sulfate (DHEAS), androstenedione, testosterone and sex hormone-binding globulin (SHBG) were measured at gestational weeks 17 and 33. The main outcome measures were weight and length at birth. Associations between maternal androgen levels and offspring birth weight and length were investigated using multiple linear regression modeling adjusted for potential confounding by maternal height, pre-pregnancy body mass index, smoking, parity, offspring gender and gestational age at birth.

RESULTS

Elevated maternal testosterone levels at week 17 and 33 were both associated with lower birth weights and lengths. Accordingly, at week 17, an increase in maternal testosterone levels from the 25th to the 75th percentile was associated with a decrease in birth weight by 160 g (95% confidence interval (CI); 29-290 g), while at week 33 that estimate was 115 g (95% CI; 21-207 g). No similar associations were observed for DHEAS, androstenedione or SHBG.

CONCLUSIONS

Elevated maternal testosterone levels during human pregnancy are associated with growth restriction in utero. Our results support animal studies, which have indicated that maternal androgen levels influence intrauterine offspring environment and development.

Beneficial effect of metformin on pregnancy outcome in women with polycystic ovary syndrome is not associated with major changes in C-reactive protein levels or indices of coagulation

In women with polycystic ovary syndrome, C-reactive protein levels and D-dimer, antithrombin III, activated protein C resistance, and activated partial thromboplastin time were unaffected by metformin treatment throughout pregnancy. Protein C levels increased slightly in the metformin group compared with the placebo group.

Placental passage of metformin in women with polycystic ovary syndrome

Metformin passes the placenta. Fetal serum levels are comparable with maternal values.

Early second-trimester maternal hyperandrogenemia and subsequent preeclampsia: a prospective study

OBJECTIVE

To explore the hypothesis that maternal androgen levels are elevated before the onset of preeclampsia.

METHODS

A case-control study in three university hospitals in Norway and Sweden included 29 women with mild preeclampsia and 142 controls. Maternal levels of dehydroepiandrosterone sulfate (DHEAS), androstenedione, testosterone and sex hormone binding globulin (SHBG) were measured, and the free testosterone index (FTI) was calculated in weeks 17 and 33 of gestation.

RESULTS

Androstenedione, testosterone and FTI were elevated in gestational weeks 17 and 33 in women who eventually developed preeclampsia, while DHEAS was elevated at week 17 only. At week 17 elevated testosterone and FTI were seen in women bearing both male and female fetuses. At week 33 elevated levels of androstenedione, testosterone and FTI was seen in women with male fetuses only. Comparing the lower tertile with the upper tertile of FTI at week 17 of gestation gave an odds ratio (OR) for preeclampsia of 3.7 [95% confidence interval (CI) 1.3-10.4].

CONCLUSION

Maternal androgen levels are already elevated in the early second trimester among women who eventually develop preeclampsia. Thus hyperandrogenism may be considered as an early risk marker of preeclampsia and it might be involved in the pathogenesis of preeclampsia.

Metformin reduces pregnancy complications without affecting androgen levels in pregnant polycystic ovary syndrome women: results of a randomized study

BACKGROUND

Investigation of a possible effect of metformin on androgen levels in pregnant women with polycystic ovary syndrome (PCOS).

METHODS

A prospective, randomized, double-blind, placebo-controlled pilot study was conducted. Forty pregnant women with PCOS received diet and lifestyle counselling and were randomized to either metformin 850 mg twice daily or placebo. Primary outcome measures were changes in serum levels of dehydroepiandrosterone sulphate, androstenedione, testosterone, sex hormone-binding globulin, and free testosterone index. Secondary outcome measures were pregnancy complications and outcome. Two-tailed t-tests and chi2-tests were used.

RESULTS

Maternal androgen levels were unaffected by metformin treatment in pregnant women with PCOS. While none of the 18 women in the metformin group experienced a severe pregnancy or post-partum complication, seven of the 22 (32%) women experienced severe complications in the placebo group (P = 0.01).

CONCLUSIONS

Metformin treatment did not reduce maternal androgen levels in pregnant women with PCOS. In the metformin-treated group we observed a reduction of severe, pregnancy and post-partum complications. Metformin treatment of pregnant PCOS women may reduce complications during pregnancy and in the post-partum period.

Metformin treatment before IVF/ICSI in women with polycystic ovary syndrome; a prospective, randomized, double blind study

BACKGROUND

Our aim was to investigate the effect of pre-treatment with metformin in women with polycystic ovary syndrome (PCOS) scheduled for IVF stimulation.

METHODS

Seventy-three oligo/amenorrhoeic women with polycystic ovaries and at least one of the following criteria: hyperandrogenaemia, elevated LH/FSH ratio, hyperinsulinism, decreased SHBG levels or hirsutism, were studied. Normal weight and overweight patients were randomized separately in a prospective, randomized, double blind study. All patients were treated for at least 16 weeks with metformin (1000 mg bid) or placebo ending on the day of HCG injection.

RESULTS

No differences were found in the primary end-points: duration of FSH stimulation 14.4 (13.1-15.7) versus 14.2 (12.6-15.7) days or estradiol on the day of HCG injection 6.8 (5.3-8.2) versus 7.6 (5.6-9.6) nmol/l in the metformin and placebo groups, respectively. The secondary end-points number of oocytes, fertilization rates, embryo quality, pregnancy rates and clinical pregnancy rates were equal. However, in the normal weight subgroup (BMI <28 kg/m(2), n = 27), pregnancy rates following IVF were 0.71 (0.63-0.79) versus 0.23 (0.15-0.31) in the metformin and placebo groups, respectively (P = 0.04). Overall clinical pregnancy rates were equal: 0.51 (0.34-0.68) versus 0.44 (0.27-0.62) in the metformin and placebo groups, respectively. However, in the normal weight subgroup, clinical pregnancy rates were 0.67 (0.43-0.91) and 0.33 (0.06-0.60), respectively (P = 0.06).

CONCLUSIONS

Pre-treatment with metformin prior to conventional IVF/ICSI in women with PCOS does not improve stimulation or clinical outcome. However, among normal weight PCOS women, pre-treatment with metformin tends to improve pregnancy rates. Further studies in subgroups of PCOS women are required.

Clinical, biochemical and ultrasonographic characteristics of Scandinavian women with PCOS

BACKGROUND

The aim was to investigate the clinical, biochemical and ultrasonographic characteristics of Scandinavian women with polycystic ovarian syndrome (PCOS), and to see whether there were any differences between eumenorrhoic and oligoamenorrhoic women.

METHODS

Eighty women aged between 18 and 40 years with PCOS were investigated in a prospective study. The inclusion criteria were polycystic ovaries (PCO), body mass index (BMI) >25 kg/m(2) and at least one of the following: testosterone >2.5 nmol/L, sex hormone binding globulin (SHBG) <30 nmol/L, fasting C-peptide >1.0 nmol/L, oligoamenorrhea or hirsutism.

RESULTS

Eumenorrhoic and oligoamenorrhoic women with PCOS did not differ in age, age at menarche, blood pressure, BMI, free testosterone index (FTI), insulin C-peptide or fasting glucose. A thicker endometrium and a smaller ovarian volume were found in eumenorrhoic compared to oligoamenorrhoic patients. There was linear association between BMI and the number of diagnostic criteria met.

CONCLUSION

BMI was associated with the severity of the PCOS. There were no differences in basic clinical and biochemical parameters between eumenorrhoic and oligoamenorrhoic patients with PCOS.

Six-month treatment with low-dose dexamethasone further reduces androgen levels in PCOS women treated with diet and lifestyle advice, and metformin

BACKGROUND

The purpose of this study was to investigate the effect of low-dose dexamethasone on androgen levels in women with polycystic ovary syndrome (PCOS) treated with diet and lifestyle counselling, and metformin.

METHODS

A prospective, randomized, double blind, placebo-controlled study was carried out. Thirty-eight women with PCOS were randomized to either dexamethasone 0.25 mg daily or placebo for 26 weeks. All received diet and lifestyle counselling at inclusion and metformin 850 mg three times daily during the whole study. Main outcome measures were: androgen levels, body mass index (BMI), insulin c-peptide, fasting glucose and serum lipids. Two-tailed t-tests and Pearson's statistics were used.

RESULTS

Compared with the placebo, dexamethasone reduced testosterone by 27%, androstenedione by 21%, dehydroepiandrosterone sulphate by 46% and free testosterone index by 50% in women with PCOS treated with diet and lifestyle advice, and metformin. BMI, fasting glucose, insulin c-peptide and serum lipid levels were unaffected.

CONCLUSIONS

Six-month, low-dose dexamethasone treatment further reduces androgen levels in metformin-treated PCOS women.

Androgen levels in pregnant women decrease with increasing maternal age

BACKGROUND

To investigate a possible effect of age on maternal androgen levels in uncomplicated pregnancies.

METHODS

A study of 134 parous women with uncomplicated pregnancies was carried out at three university hospitals in Norway and Sweden. Maternal levels of androstenedione, dehydroepiandrosterone sulphate, testosterone and the free testosterone index were measured during weeks 17 and 33 of pregnancy.

RESULTS

Maternal levels of androstenedione and testosterone had a negative association with maternal age in weeks 17 and 33 of pregnancy, while dehydroepiandrosterone sulphate and the free testosterone index were associated negatively in week 33 only. Adjustment for maternal parity, pre-pregnancy body mass index, smoking and fetal gender did not affect the results.

CONCLUSIONS

Maternal androgen levels decrease with increasing maternal age. The cause and possible implication of this finding remain unknown.

Nausea and vomiting associate with increasing maternal androgen levels in otherwise uncomplicated pregnancies

BACKGROUND

The objective of the present study was to investigate the hypothesis that maternal androgen levels associate with nausea and vomiting in otherwise uncomplicated pregnancies.

METHODS

One hundred and twenty-nine women with uncomplicated pregnancies, reported nausea and vomiting in weeks 17, 25, 33, 37, and when admitted for delivery. Maternal levels of androstenedione, dehydroepiandrosterone sulfate (DHEAS), testosterone, and sex hormone binding globulin (SHBG) were measured and the free testosterone index calculated in weeks 17 and 33 of pregnancy.

RESULTS

Maternal levels of androstenedione and DHEAS associated positively with nausea and vomiting in week 17. In week 33, testosterone and DHEAS associated positively with nausea and vomiting, as well as androstenedione. A calculated emesis score associated positively with increasing average levels of both androstenedione and testosterone during pregnancy, as well as the free testosterone index.

CONCLUSIONS

Nausea and vomiting associate with increasing maternal androgen levels during otherwise uncomplicated pregnancies. Whether androgens are causally related to emesis gravidarum remains unknown.

[Beta blockers or ACE inhibitors following myocardial infarction in patients with diabetes?]

BACKGROUND

Total mortality after myocardial infarction is about twice as high for diabetic as for non-diabetic subjects. ACE inhibitors are regarded as a first drug for all diabetics, also for post-infarction treatment.

MATERIAL AND METHODS

We have reviewed the literature with an emphasis on the effect on hard end points in diabetic subjects treated for at least six weeks with beta blockers or ACE inhibitors after myocardial infarction.

RESULTS

We identified eight post-infarction studies for which subgroup analyses of diabetic subjects were available, four with beta blockers and four with ACE inhibitors. We found that beta blockers without intrinsic sympathetic activity probably reduce total mortality more than ACE inhibitors do. The reduction of total mortality after treatment with beta blockers was 56-63%, compared to 12-35% after treatment with ACE inhibitors.

INTERPRETATION

Beta blockers should be the preferred choice in post-infarction treatment of diabetics. ACE inhibitors and beta blockers used together give no further reduction in mortality.

Folate administration reduces circulating homocysteine levels in NIDDM patients on long-term metformin treatment

OBJECTIVES

Metformin treatment increases circulating homocysteine levels. We studied whether administration of folate reduces serum total homocysteine levels in patients on long-term metformin treatment.

DESIGN

A prospective, randomized, double-blind, placebo-controlled study lasting for 12 weeks and taking place in a university hospital setting.

SUBJECTS

Thirty patients treated with a metformin dose of at least 1000 mg day-1 for a minimum of 1 year were included. At baseline serum total homocysteine levels were within the reference range. One patient who withdrew and one who died were excluded from the statistical evaluation. Twenty-six of the remaining patients suffered from NIDDM, the other two from hyperlipidaemia.

INTERVENTION

Patients were randomized into two groups at week 0. The folate group received 0.25 mg day-1 of folate in addition to 60 mg day-1 of Fe2+, while the placebo group received only 60 mg day-1 of Fe2+.

MAIN OUTCOME MEASURES

Fasting homocysteine, cysteine, cysteinylglycine, vitamin B12 and folate were measured at week 0, 4 and 12. Changes from week 0 to week 4 and from week 0 to week 12 were calculated.

RESULTS

Folate administration reduced serum levels of total homocysteine in the folate group as compared with the placebo group by 13.9% (P < 0.01) and 21.7% (P < 0.001) at week 4 and 12, respectively. In the folate group versus the placebo group serum levels of vitamin B12 increased by 9.9% (P = 0.010) and 9.6% (P = 0.043) while folate levels increased by 96.9 and 89.9% at week 4 and 12, respectively.

CONCLUSION

The present study indicates that the homocysteine-increasing effect of metformin can be counteracted by folate administration.

Metformin increases circulating tumour necrosis factor-alpha levels in non-obese non-diabetic patients with coronary heart disease

Metformin reduces insulin resistance and hyperinsulinaemia, as well as lipid levels and body weight. The mechanisms behind these effects are likely to involve intracellular insulin signalling. Recent evidence implicates tumour necrosis factor-alpha (TNF-alpha) as a modulatory factor on insulin resistance. The present investigation was undertaken to clarify whether metformin affects TNF-alpha and soluble TNF receptor levels. Sixty non-diabetic men with coronary heart disease were treated with diet and lifestyle advice and lovastatin 40 mg/day during a 4-week run-in period. During this period TNF-alpha and soluble TNF receptor p75 remained unchanged, whereas soluble TNF receptor p55 increased by 8% (P < 0.05). Twelve weeks of metformin treatment increased TNF-alpha by 33% (P < 0.05). This effect was restricted to non-obese patients in whom TNF-alpha increased by 68% (P < 0.01). Soluble TNF receptors p55 and p75 remained unchanged in the whole group, whereas soluble TNF receptor p55 increased by 11% (P < 0.05) in non-obese patients. Since metformin reduces insulin resistance both in obese and non-obese subjects but increases TNF-alpha levels only in the latter, it is concluded that the drug does not exert its effect on insulin resistance through regulation of circulating TNF-alpha levels.

Evidence for dissociation of insulin- and weight-reducing effects of metformin in non-diabetic male patients with coronary heart disease

Metformin effects on insulin resistance and insulin/glucose relationships during an oral glucose tolerance test (OGTT) were investigated in 60 non-diabetic male patients previously treated with coronary artery bypass surgery or angioplasty in an open, 12 week prospective study. During a 4 week run-in period, all patients were treated with diet and lifestyle advice and lovastatin 40 mg daily. Lovastatin treatment was continued in all the patient throughout the study. After randomization, the metformin group got additional treatment with metformin up to 2000 mg/day. Fasting plasma glucose levels and glucose area during OGTT remained unaffected by metformin treatment. Insulin resistance, assessed as the insulin area/glucose area ratio during OGTT decreased by 24% (P = 0.028) in the whole group and by 30% in obese subjects (P = 0.049). Notably, the reduction in body weight by metformin treatment did not correlate with amelioration of insulin resistance or changes in lipid levels. However, changes in insulin resistance correlated with changes in lipid levels. Hence, metformin effects on insulin resistance and body weight appear to be mediated, at least partly, by different mechanisms, while metformin effects on insulin resistance and lipid metabolism are associated in non-diabetic subjects.

Metformin increases total serum homocysteine levels in non-diabetic male patients with coronary heart disease

It is known that the metabolism of homocysteine (Hcy) depends on the vitamins B6, B12 and folate, and furthermore that metformin reduces serum vitamin B12 levels. In order to investigate whether metformin treatment affects serum total Hcy (tHcy) levels we performed an open, prospective, randomised study in 60 non-diabetic male patients with cardiovascular disease. After a 4-week run-in period with lovastatin 40 mg day-1, and diet and lifestyle advice, patients were randomised into two groups, both continuing the run-in treatment. One group received metformin up to 2000 mg day-1, whereas the control group got no additional treatment. After 12 and 40 weeks of metformin treatment, tHcy levels increased moderately but significantly by 7.2% (p < 0.05) and 13.8% (p < 0.05) in the metformin group relative to the control group, whereas serum vitamin B12 levels decreased by 13.4% (p < 0.0005) and 17.7% (p < 0.0005), respectively. Serum folate levels did not change after 12 weeks, but decreased by 8.0% after 40 weeks (p = 0.061) relative to the control group. Serum levels of total cysteine and methylmalonic acid (MMA) did not change. In conclusion, metformin treatment increased tHcy levels and decreased levels of vitamin B12 and folate. Since MMA levels were unchanged, it remains an open question whether the increase in tHcy levels is secondary to reduced vitamin B12 levels, folate levels or a combination of both.

[Sulfonylurea-induced hypoglycemia. An iatrogenic and potentially fatal condition]

Sulfonylureas are the most frequently used peroral antidiabetic drugs in Norway. Five cases of serious sulfonylurea-induced hypoglycemia are described. In one of these cases glibenklamid-induced hypoglycemia was thought to be the direct cause of death. A review of the literature indicates that glibenclamide induces more frequent and serious hypoglycemias than other sulfonylureas do. The author discusses the possible mechanisms behind these differences, and the conditions predisposing to sulfonylurea-induced hypoglycemia. It is recommended to check blood glucose whenever a patient's diagnosis has not been adequately clarified.

Metformin improves blood lipid pattern in nondiabetic patients with coronary heart disease

OBJECTIVES

To study whether the addition of metformin further improves the blood lipid pattern in non-diabetic patients with coronary heart disease already treated with lovastatin, diet and lifestyle advice.

DESIGN

An open, prospective, randomized study in a university hospital setting.

SUBJECTS

Sixty non-diabetic male patients previously treated with coronary artery bypass surgery or angioplasty and with serum cholesterol > or = 6.0 mmol L-1 and/or HDL-cholesterol < or = 1.2 mmol L-1.

INTERVENTIONS

After a 4-week run-in period with lovastatin (40 mg day-1), and diet and lifestyle advice, patients were randomized into two groups, both continuing the run in treatment. One group received metformin up to 2000 mg day-1; the control group got no additional treatment.

MAIN OUTCOME MEASURES

Fasting serum lipids, glucose and weight were registered at entrance (= week-4), and at weeks 0, 4 and 12. Changes from week 0 to week 4 and from week 0 to week 12 were compared. Side-effects of the treatment were also registered.

RESULTS

Metformin lowered the LDL/HDL-cholesterol ratio by 12 and 6% at weeks 4 and 12, respectively, and reduced body weight by 1.8 kg at week 12. There was also a transient lowering effect on LDL-cholesterol and apolipoprotein B. In the normal weight subgroup of patients (body mass index < 27 kg m-2), metformin induced a decrease in total cholesterol (-9%). LDL-cholesterol (-12%). LDL/HDL-cholesterol ratio (-10%) and apolipoprotein B (-7%), as compared to the control group. In this subgroup, body weight and fasting glucose were unaffected by metformin. Thus, the lipid lowering effect in normal weight patients was not secondary to changes in body weight or fasting glucose. In overweight patients (body mass index > 27 kg m-2), metformin had no significant effects on blood lipids, but induced a weight loss of -3.0 kg and a transient reduction of fasting glucose. No side-effects were registered apart from those expected from each individual drug.

CONCLUSIONS

Metformin given for 12 weeks as a supplement to lovastatin, diet and lifestyle advice to non-diabetic male patients with coronary heart disease further improves the lipid pattern in normal weight patients, and reduces weight in the overweight patients. Because metformin is cheap and other lipid lowering drugs are expensive, the potential of metformin as a lipid lowering agent should be further investigated.