The effects of metformin on the capillary permeability to albumin in women patients with cyclic edema

Edema related to treatment with psychotropic drugs

Edema as an adverse drug reaction is a commonly underestimated yet potentially debilitating condition. This study analyzes the incidence of severe psychotropic drug-induced edema (e.g., edema affecting the face, legs, or multiple body parts and lasting for more than 1 week, or in any case necessitating subsequent diuretic use) among psychiatric inpatients. The cases under examination are derived from an observational pharmacovigilance program conducted in German-speaking countries ("Arzneimittelsicherheit in der Psychiatrie", AMSP) from 1993 to 2016. Among the 462,661 inpatients monitored, severe edema was reported in 231 cases, resulting in an incidence of 0.05%. Edema occurred more frequently in women (80% of all cases) and older patients (mean age 51.8 years). Pregabalin had the highest incidence of severe edema, affecting 1.46‰ of patients treated with pregabalin, followed by mirtazapine (0.8‰). The majority of edema cases showed a positive response to appropriate countermeasures, such as dose reduction and drug discontinuation, and resolved by the end of the observation period. While most instances of drug-induced edema are reversible, they can have a significant impact on patient well-being and potentially result in decreased treatment adherence. It is, therefore, crucial to remain vigilant regarding risk-increasing circumstances during treatment with psychotropic drugs.

Effects of insulin analogs as an add-on to metformin on cutaneous microcirculation in type 2 diabetic patients

BACKGROUND

A single insulin injection was shown to improve microcirculatory blood flow. Our aim was to examine the effects of 4weeks of insulin therapy by three randomly assigned insulin analog regimens (Detemir, Aspart, and their combination) on cutaneous blood flow (CBF) and microcirculatory endothelial function as an add-on to metformin in type 2 diabetic patients poorly controlled on oral antidiabetic treatment.

METHODS

Fourty-two type 2 diabetic patients with no history of cardiovascular disease in secondary failure to oral antidiabetic agents had CBF measurements before and after acetylcholine (Ach) iontophoretic administration. CBF measurements were performed at fasting and after a standardized breakfast during the post-prandial period. Before randomization (Visit 1, V1) during the tests, participants took only metformin. The same tests were repeated after 4weeks of insulin treatment (Visit 2, V2).

RESULTS

Thirty-four patients had good quality recordings for both visits. During V1, CBF and CBF response to Ach increased in the post-prandial period. After 4weeks of insulin treatment, metabolic parameters improved. Compared to V1, CBF at fasting did not increase at V2 but there was an improvement in endothelial function at fasting after Ach iontophoresis, without difference across insulin regimens. Oxidative stress markers were not modified, and E-selectin and vascular cell adhesion molecule 1 levels decreased after insulin treatment, without differences between insulin groups.

CONCLUSIONS

A strategy of improving glycemic control for 4weeks with insulin analogs improves microcirculatory endothelial reactivity and reduces endothelial biomarkers at fasting, whatever the insulin regimen used. Insulin therapy associated to metformin is able to improve fasting microvascular endothelial function even before complete metabolic control.

Long term use of metformin in idiopathic cyclic edema, report of thirteen cases and review of the literature

INTRODUCTION

Idiopathic cyclic edema (ICE) is a rare cause of edema. To date, there is no standard of care. The physiopathology of ICE could be explained by an impairment of capillary permeability. In 1995, a study demonstrated the efficacy of metformin on symptoms and capillary permeability. We evaluated ICE-patients who were treated with metformin in our department.

METHODS

We retrospectively included patients diagnosed for ICE between January 1997 and October 2013. ICE was diagnosed in the presence of edema after excluding other etiologies. LANDIS test was used to support ICE diagnosis in all patients. The absence of edema at follow-up was considered as complete response (CR), partial decreased was considered as partial response (PR). Adverse events were recorded.

RESULTS

Thirteen patients have accepted to use metformin. The median treatment duration was 28.5 months [8-167] and the median follow-up of treated patients was 40.5 months [14-167]. CR was reached in 10 patients (77%), and PR in 2 patients (15%). Two patients reported side-effects as diarrheas and one of them stopped the treatment due to mild diarrhea.

CONCLUSION

We report the interest and tolerance of the long-term use of metformin in ICE. No severe adverse events were noticed. A prospective study is needed to confirm the efficacy of metformin in ICE-patients.

Review: 50 years later: is metformin a vascular drug with antidiabetic properties?

Since the clinical demonstration of a protective effect of metformin against chronic diabetic angiopathy in the United Kingdom Prospective Diabetes Study, many data have accumulated which confirm such effects in acute or chronic situations as diverse as ischaemia, non-diabetic insulin resistant states and diabetes. Recent years have provided several mechanisms of action and further documented some unique properties of this compound such as improvements in microcirculatory flow, glycation and oxidative stress. In particular, the latter effect could be shown in mitochondria, i.e. the most important sources of reactive oxygen species in diabetes. Specific, non-toxic actions of metformin at the level of the mitochondrial respiratory chain also prevent apoptosis, another mechanism to explain the long-term protection afforded by metformin. Noteworthy, most of these effects of metformin are unrelated to drug dosage and largely independent of its antihyperglycaemic effect (intrinsic properties). These new data open potential avenues for larger therapeutic utilisations of this drug, 50 years after its launch for the treatment of type 2 diabetes.

Effects of two weeks of metformin treatment on whole-body glycocalyx barrier properties in db/db mice

Background

The anti-diabetic drug metformin has been demonstrated to exert a protective effect against vascular complications in diabetes independent of its glucose lowering action. Since the endothelial glycocalyx has been indicated to have important vasculoprotective properties and to be vulnerable to degradation by hyperglycemic conditions, we evaluated in the current study the effect of short-term metformin treatment on whole-body glycocalyx barrier properties in a mouse model of non-insulin dependent diabetes mellitus (db/db mouse).

Methods

Glycocalyx barrier properties were measured in an acute experiment in three groups of mice: 1) db/db mice without treatment serving as controls, 2) db/db mice which received metformin for two weeks in the drinking water serving as experimental group, and 3) C57Bl/6 mice serving as reference group. Animals were put under anesthesia (ketamine, medetomidine, and atropine) and carotid artery blood pressure was continuously monitored. To probe the glycocalyx a mixture of the tracers FITC-labeled 70 kDa dextrans (Dex70) or fluorescein-labeled red blood cells (RBCs) versus Texas Red-labeled 40 kDa dextrans (Dex40) was infused and blood samples subsequently collected for 30 min to determine the initial vascular distribution volume and clearance of these tracers. Urine was collected and dry-to-wet weight of heart and kidney were determined after the experiment. Group differences were tested using unpaired t-tests.

Results

Metformin treatment did not affect body weight, fasting blood glucose and arterial blood pressure. Compared to C57Bl/6 mice, db/db mice showed a diminished initial exclusion and increased vascular clearance of Dex70 versus Dex40 (P < 0.05), and both were improved by the metformin treatment (P < 0.05). While urine production was higher in the db/db mice compared to C57Bl/6 (P < 0.05), heart and kidney of the metformin treated animals showed comparable dry-to-wet weights compared to the C57Bl/6 mice.

Conclusions

Two weeks of metformin in the drinking water is associated with an improvement in glycocalyx barrier properties in db/db mice, as evidence by an enhanced exclusion and retention of 70 kDa dextrans in the vasculature. In addition, metformin improved hydration of heart and kidney. Previous reported cardiovascular benefits of metformin may well involve an improvement of the endothelial glycocalyx.

Metformin: effects on micro and macrovascular complications in type 2 diabetes

INTRODUCTION

The antihyperglycaemic agent metformin is widely used in the treatment of type 2 diabetes. Data from the UK Prospective Diabetes Study and retrospective analyses of large healthcare databases concur that metformin reduces the incidence of myocardial infarction and increases survival in these patients. This apparently vasoprotective effect appears to be independent of the blood glucose-lowering efficacy.

EFFECTS OF METFORMIN

Metformin has long been known to reduce the development of atherosclerotic lesions in animal models, and clinical studies have shown the drug to reduce surrogate measures such as carotid intima-media thickness. The anti-atherogenic effects of metformin include reductions in insulin resistance, hyperinsulinaemia and obesity. There may be modest favourable effects against dyslipidaemia, reductions in pro-inflammatory cytokines and monocyte adhesion molecules, and improved glycation status, benefiting endothelial function in the macro- and micro-vasculature. Additionally metformin exerts anti-thrombotic effects, contributing to overall reductions in athero-thrombotic risk in type 2 diabetic patients.

Microcirculation in insulin resistance and diabetes: more than just a complication

The microvascular bed is an anatomical entity which is governed by specific, highly regulated mechanisms which are closely adapted to the specific function of each vascular segment. Among those, small arteriolar vasomotion and capacity of small vessels to constrict in response to physical and humoral stimuli play a major role. Other processes of importance for the adequacy of nutritive perfusion are haemorheological properties of whole blood and red cells, adhesiveness of leukocytes and capillary permeability. This review provides some description of these phenomena, how they impact on organ function and how they appear in diabetes. Metformin, as a unique example among the drug arsenal, exerts various effects preferentially at the level of smallest vessels (arterioles, capillaries, venules). This review summarises our actual knowledge and includes several new data showing its high potential for reducing microvascular dysfunction. Most of these unique properties have also been demonstrated in non-diabetic animals or humans, suggesting they are intrinsic to the drug and not secondary to diabetic metabolic improvement. A particular focus is put on the relevance of metformin's capacity to stimulate slow wave arteriolar vasomotion and improve functional capillary density, whereby nutritive flow can be re-established. Finally, the implication of microcirculation in other aspects of insulin resistance and diabetes, such as macroangiopathy and metabolic control, is discussed and strengthens the concept of a broad involvement of microvascular dysfunction in these diseases as well as the potential interest of introducing adapted treatment early in the history of a patient's diabetes.

Impairment of lymphatic function in women with gynoid adiposity and swelling syndrome

The current study sought to investigate the factors, in particular anthropometric parameters, associated with an impairment of capillary permeability and lymphatic function in a large series of women complaining of a swelling syndrome. One hundred ninety-seven women with a swelling syndrome were investigated, 43 of whom were obese (body mass index [BMI]>30 kg/m2), 77 overweight (BMI=25 to 30 kg/m2). Thirty-five of the 197 women had abdominal adiposity (waist-to-hip ratio [WHR]>0.85). Capillary filtration of albumin and lymphatic function were studied by means of an isotopic test using 99mtechnetium-labeled albumin and venous compression. This test allowed measurement of interstitial albumin retention (AR) and the evaluation of lymphatic function by analyzing the radioactivity disappearance curve after removal of venous compression with the fast Fourier transform (low frequency/high frequency [LF/HF]). Body composition was studied by the bioelectrical impedance method. WHR correlated with fasting blood glucose (P=.03), serum triglyceride (P<.0001), and apoprotein B (P=.008) levels. AR was increased (> or =8 %) in 117 women (59.4%) and LF/HF (> or =1 %) in 149 cases (75.6%). Extracellular water (ECW) was increased (>107% of the theoretical value) in 144 cases (73.1%). LF/HF correlated negatively with age (P=.001), BMI (P=.006), WHR (P<.0001), and fat mass (P=.002). In the multivariate analysis taking age, BMI, and WHR as independent variables, LF/HF correlated significantly with WHR (P<.005). There was a trend to a higher prevalence of an increase in AR in the women with an increase in ECW (61.8 %) as compared with those without an increase in ECW (52.8%). We conclude that abdominal adiposity is associated with metabolic disorders secondary to insulin resistance as previously demonstrated, whereas lymphatic dysfunction is mainly associated with gynoid adiposity. Besides microcirculatory disorders, changes in the secretory regulation of hormones involved in salt and water retention are likely to play an important role in ECW excess.

Extra cellular water and increase in capillary permeability to albumin in overweight women with swelling syndrome

OBJECTIVE

To evaluate extracellular water (ECW) in the recumbent and the upright position, in overweight and lean women with swelling syndrome, and to correlate the excess in ECW with an increase in capillary filtration of albumin (CFA).

PATIENTS

Fifty-one women with a swelling syndrome were investigated, 26 of whom were overweight.

MEASUREMENTS

ECW was measured by the bioelectrical impedance method, in the recumbent position and again after a postural test which consisted of walking around for 30 min. CFA was studied by an isotopic test using 99m technetium-labelled albumin.

RESULTS

ECW increased (>107% of the theoretical value) in 22 of the 26 overweight patients and 23 of the 25 lean patients. The CFA isotopic test was abnormal in half (11/22) of the overweight patients with increased ECW and in three of the four overweight patients with a normal ECW value. It was abnormal in 18 of the 23 lean patients with increased ECW and in the two lean patients with a normal ECW value. During the postural test, a significant (by> or =4%) increase in ECW occurred in a higher proportion of overweight patients tested (14/22) than among the lean women tested (0/5; P=0. 04).

CONCLUSIONS

The swelling syndrome is indeed related to an increase in ECW in lean and overweight subjects and to a further increase in ECW after a postural test only in the overweight patients. It is also associated with microcirculatory disorders in most of the lean patients who complain of swelling and in only half of the overweight patients with the same complaints, which suggests that other factors (e.g. hormonal disorders) may be involved in the overweight patients. International Journal of Obesity (2000)24, 126-130