Metformin and digestive disorders

ACOG Practice Bulletin No. 210: Fecal Incontinence

Fecal incontinence, or the involuntary leakage of solid or loose stool, is estimated to affect 7-15% of community-dwelling women (1). It is associated with reduced quality of life, negative psychologic effects, and social stigma (2), yet many women do not report their symptoms or seek treatment. Less than 3% of women who do self-report fecal incontinence will have this diagnosis recorded in their medical record (3). Obstetrician-gynecologists are in a unique position to identify women with fecal incontinence because pregnancy, childbirth, obstetric anal sphincter injuries (OASIS), and pelvic floor dysfunction are important risk factors that contribute to fecal incontinence in women. The purpose of this Practice Bulletin is to provide evidence-based guidelines on the screening, evaluation, and management of fecal incontinence to help obstetrician-gynecologists diagnose the condition and provide conservative treatment or referral for further work up and surgical management when appropriate. For discussion on fecal incontinence associated with OASIS, see Practice Bulletin No. 198, Prevention and Management of Obstetric Lacerations at Vaginal Delivery (4).

Metformin and Micronutrient Status in Type 2 Diabetes: Does Polypharmacy Involving Acid-Suppressing Medications Affect Vitamin B12 Levels?

Metformin is the first-choice drug in uncomplicated type 2 diabetes (T2DM) and is effective in improving glycaemic control. It is the most widely prescribed oral antidiabetic medicine and has a good safety profile. However, there is an abundance of evidence that metformin use is associated with decreased Vitamin B12 status, though the clinical implications of this in terms of increased risk of diabetic peripheral neuropathy are debated. There is growing evidence that other B vitamins, vitamin D and magnesium may also be impacted by metformin use in addition to alterations to the composition of the microbiome, depending on the dose and duration of therapy. Patients using metformin for prolonged periods may, therefore, need initial screening with intermittent follow-up, particularly since vitamin B₁₂ deficiency has similar symptoms to diabetic neuropathy which itself affects 40-50% of patients with T2DM at some stage. Among patients with T2DM, 40% are reported to experience symptomatic gastroesophageal reflux disease (GORD), of whom 70% use oral antidiabetic medications. The most common medications used to treat GORD are proton pump inhibitors (PPIs) and antagonists of histamine selective H₂ receptors (H₂RAs), both of which independently affect vitamin B₁₂ and magnesium status. Research indicates that co-prescribing metformin with either PPIs or H₂RAs can have further deleterious effects on vitamin B₁₂ status. Vitamin B12 deficiency related to metformin and polypharmacy is likely to contribute to the symptoms of diabetic neuropathy which may frequently be under-recognised. This review explores current knowledge surrounding these issues and suggests treatment strategies such as supplementation.

Organic Cation Transporters in Health and Disease

The organic cation transporters (OCTs) OCT1, OCT2, OCT3, novel OCT (OCTN)1, OCTN2, multidrug and toxin exclusion (MATE)1, and MATE kidney-specific 2 are polyspecific transporters exhibiting broadly overlapping substrate selectivities. They transport organic cations, zwitterions, and some uncharged compounds and operate as facilitated diffusion systems and/or antiporters. OCTs are critically involved in intestinal absorption, hepatic uptake, and renal excretion of hydrophilic drugs. They modulate the distribution of endogenous compounds such as thiamine, L-carnitine, and neurotransmitters. Sites of expression and functions of OCTs have important impact on energy metabolism, pharmacokinetics, and toxicity of drugs, and on drug-drug interactions. In this work, an overview about the human OCTs is presented. Functional properties of human OCTs, including identified substrates and inhibitors of the individual transporters, are described. Sites of expression are compiled, and data on regulation of OCTs are presented. In addition, genetic variations of OCTs are listed, and data on their impact on transport, drug treatment, and diseases are reported. Moreover, recent data are summarized that indicate complex drug-drug interaction at OCTs, such as allosteric high-affinity inhibition of transport and substrate dependence of inhibitor efficacies. A hypothesis about the molecular mechanism of polyspecific substrate recognition by OCTs is presented that is based on functional studies and mutagenesis experiments in OCT1 and OCT2. This hypothesis provides a framework to imagine how observed complex drug-drug interactions at OCTs arise. Finally, preclinical in vitro tests that are performed by pharmaceutical companies to identify interaction of novel drugs with OCTs are discussed. Optimized experimental procedures are proposed that allow a gapless detection of inhibitory and transported drugs.

Understanding the glucoregulatory mechanisms of metformin in type 2 diabetes mellitus

Despite its position as the first-line drug for treatment of type 2 diabetes mellitus, the mechanisms underlying the plasma glucose level-lowering effects of metformin (1,1-dimethylbiguanide) still remain incompletely understood. Metformin is thought to exert its primary antidiabetic action through the suppression of hepatic glucose production. In addition, the discovery that metformin inhibits the mitochondrial respiratory chain complex 1 has placed energy metabolism and activation of AMP-activated protein kinase (AMPK) at the centre of its proposed mechanism of action. However, the role of AMPK has been challenged and might only account for indirect changes in hepatic insulin sensitivity. Various mechanisms involving alterations in cellular energy charge, AMP-mediated inhibition of adenylate cyclase or fructose-1,6-bisphosphatase 1 and modulation of the cellular redox state through direct inhibition of mitochondrial glycerol-3-phosphate dehydrogenase have been proposed for the acute inhibition of gluconeogenesis by metformin. Emerging evidence suggests that metformin could improve obesity-induced meta-inflammation via direct and indirect effects on tissue-resident immune cells in metabolic organs (that is, adipose tissue, the gastrointestinal tract and the liver). Furthermore, the gastrointestinal tract also has a major role in metformin action through modulation of glucose-lowering hormone glucagon-like peptide 1 and the intestinal bile acid pool and alterations in gut microbiota composition.

Associations of chronic diarrhoea with non-alcoholic fatty liver disease and obesity-related disorders among US adults

Mechanisms explaining observed associations between diarrhoea and obesity or increased body mass index (BMI) are unclear.

The Chinese herbal formulae (Yitangkang) exerts an antidiabetic effect through the regulation of substance metabolism and energy metabolism in type 2 diabetic rats

ETHNOPHARMACOLOGICAL RELEVANCE

Type 2 diabetes mellitus (T2DM) regarded as a "hot" disease in traditional Chinese medicine (TCM). Accordingly, TCM uses a cold drug or formula such as the Chinese herbal formulae "Yitangkang" (YTK) as a treatment. YTK exhibited a good clinical antidiabetic effect in several experiments. The correlation between the properties of a TCM drug or formula and its ability to regulate the substance metabolism, the energy metabolism and the endocrine system has been proven.

AIM OF THE STUDY

The present study aiming to evaluate the mechanism of antidiabetic action of YTK from the above perspective.

MATERIALS AND METHODS

Three groups of streptozotocin (STZ)-diabetic rats have been treated with YTK at oral doses of 56 g/kg/d, 28 g/kg/d and 14 g/kg/d for 28 days using metformin as a reference drug. After treatment, several indices correlated with energy metabolism (superoxide dismutase, glutathione peroxidase, lactic dehydrogenase, adenotriphos, creatine phosphate kinase, AMPK, Na⁺-K⁺-ATPase and Respiratory Chain Complex I, II, III, IV), substance metabolism (hepatic glycogen, acetyl-coenzyme A, pyruvic acid, adipose triglyceride lipase, triglycerides, high-density lipoproteins, low-density lipoproteins, malonyldialdehyde), endocrine system (triiodothyronine, thyroxine, 17-hydroxycorticosteroid) and cyclic nucleotide system (cyclic adenosine monophosphate, cyclic guanosine monophosphate) have been determined. The specialty and tendency of YTK's effects were analyzed to elucidate its property and mechanism of action according to the theory of TCM.

RESULTS

Our findings showed that the formulae YTK could effectively regulate the levels of blood glucose, HbA1c, glucagon-like peptide-1, and significantly down-regulate the substance metabolism, energy metabolism and endocrine system indices of the diabetic rats.

CONCLUSION

These results were consistent with the TCM description of YTK as a "cold" treatment. It could provide an effective way to interpret the scientific connotation and comprehensive system of the Chinese herbal formulae.

The Impact of Glycemic Status and Metformin Administration on Red Blood Cell Indices and Oxidative Stress in Type 2 Diabetic Patients

BACKGROUND

Most guidelines all over the world recommended metformin as the first-line treatment for in type 2 diabetic patients. Therefore, the present study was suggested to assess the outcome of metformin administration and glycemic status on alterations in red blood cell (RBCs) indices as well as the oxidative stress in type 2 diabetic patients.

METHODS

Between December 2016 and October of 2017, a total of 158 eligible individuals were classified as 50 healthy subjects and 108 diabetic patients who were subdivided into six groups according to the type of anti-diabetic treatments.

RESULTS

Overall, the results elucidated that hemoglobin concentration was markedly diminished, while red cell distribution width (RDW) value was significantly (P < 0.001) elevated in all diabetic groups as compared to control. Moreover, in all diabetic groups, malondialdehyde (MDA) concentration was elevated noticeably (P < 0.001), while reduced glutathione (GSH) revealed a lower concentration (P < 0.001) than that of control.

CONCLUSION

The present study exhibited the amelioration effect of metformin administration on oxidative stress and glycemic status which reflected on some RBCs indices. However, hemoglobin concentration showed a noticeable diminution in all metformin-treated groups in spite of the improvement in glycemic and oxidative stress status which indicated that the metformin-induced anemia is independently from diabetic complications.

Effects of Drugs and Excipients on Hydration Status

Despite being the most essential nutrient, water is commonly forgotten in the fields of pharmacy and nutrition. Hydration status is determined by water balance (the difference between water input and output). Hypohydration or negative water balance is affected by numerous factors, either internal (i.e., a lack of thirst sensation) or external (e.g., polypharmacy or chronic consumption of certain drugs). However, to date, research on the interaction between hydration status and drugs/excipients has been scarce. Drugs may trigger the appearance of hypohydration by means of the increase of water elimination through either diarrhea, urine or sweat; a decrease in thirst sensation or appetite; or the alteration of central thermoregulation. On the other hand, pharmaceutical excipients induce alterations in hydration status by decreasing the gastrointestinal transit time or increasing the gastrointestinal tract rate or intestinal permeability. In the present review, we evaluate studies that focus on the effects of drugs/excipients on hydration status. These studies support the aim of monitoring the hydration status in patients, mainly in those population segments with a higher risk, to avoid complications and associated pathologies, which are key axes in both pharmaceutical care and the field of nutrition.

Combination Therapy with an SGLT2 Inhibitor as Initial Treatment for Type 2 Diabetes: A Systematic Review and Meta-Analysis

Background: Guidelines differ with regard to indications for initial combination pharmacotherapy for type 2 diabetes. Aims: To compare the efficacy and safety of (i) sodium-glucose cotransporter 2 (SGLT2) inhibitor combination therapy in treatment-naïve type 2 diabetes adults; (ii) initial high and low dose SGLT2 inhibitor combination therapy. Methods: PubMed, Embase and Cochrane Library were searched for randomised controlled trials (RCTs) of initial SGLT2 combination therapy. Mean difference (MD) for changes from baseline (HbA1c, weight, blood pressure) after 24–26 weeks of treatment and relative risks (RR, safety) were calculated using a random-effects model. Risk of bias and quality of evidence was assessed. Results: In 4 RCTs (n = 3749) there was moderate quality evidence that SGLT2 inhibitor/metformin combination therapy resulted in a greater reduction in HbA1c (MD (95% CI); −0.55% (−0.67, −0.43)) and weight (−2.00 kg (−2.34, −1.66)) compared with metformin monotherapy, and a greater reduction in HbA1c (−0.59% (−0.72, −0.46)) and weight (−0.57 kg (−0.89, −0.25)) compared with SGLT2 inhibitor monotherapy. The high dose SGLT2 inhibitor/metformin combination resulted in a similar HbA1c but greater weight reduction; −0.47 kg (−0.88, −0.06) than the low dose combination therapy. The RR of genital infection with combination therapy was 2.22 (95% CI 1.33, 3.72) and 0.69 (95% CI 0.50, 0.96) compared with metformin and SGLT2 inhibitor monotherapy, respectively. The RR of diarrhoea was 2.23 (95% CI 1.46, 3.40) with combination therapy compared with SGLT2 inhibitor monotherapy. Conclusions: Initial SGLT2 inhibitor/metformin combination therapy has glycaemic and weight benefits compared with either agent alone and appears relatively safe. High dose SGLT2 inhibitor/metformin combination therapy appears to have modest weight, but no glycaemic benefits compared with the low dose combination therapy.

Overcoming barriers to the use of metformin: patient and provider perspectives

BACKGROUND

Metformin is the first-line treatment for type 2 diabetes mellitus. Observational studies show lower rates of use than would be expected from clinical guidelines.

OBJECTIVE

We undertook a qualitative study of barriers to metformin use from the patient and provider perspective.

DESIGN

Patient focus group, patient individual interviews, provider interviews, and chart review. Purposive sampling of patients and providers in New York State.

PARTICIPANTS

Seven one-on-one patient interviews, one focus group with 13 patients, 10 provider interviews, and manual review of 1259 charts.

APPROACH

Grounded theory.

RESULTS

Both providers and patients cited potential health benefits as strong reasons to take metformin and describe it as the first-line drug for diabetes. Patients and providers both cited gastrointestinal side effects as the primary barrier to metformin use. Patients described adapting to these side effects and taking metformin at a time that minimizes them. In contrast, providers emphasized dose titration and the use of extended-release formulation as tools for minimizing side effects but were uncertain about the effectiveness of these strategies.

CONCLUSION

Metformin is positively viewed by patients and providers, but gastrointestinal side effects are a barrier to its use. There is some consensus on basic measures to improve its tolerability, but these measures are not consistently applied and lack evidence establishing their effectiveness. Pragmatic clinical trial research on optimal dose, formulation, and counseling for new metformin users should be considered.

Risk of Metformin-Associated Lactic Acidosis (MALA) in Patients After Gastric Bypass Surgery

BACKGROUND

Pharmacokinetic data suggest that the risk of metformin-associated lactic acidosis (MALA) may be increased after Roux-en-Y gastric bypass (RYGB) surgery. The aim of this study was to examine the impact of metformin on plasma lactate levels before and after RYGB surgery.

METHODS

Retrospective study of plasma lactate levels before and 3 months after RYGB surgery in patients with type 2 diabetes mellitus (T2DM) not using metformin (MET-0, N = 58), on a stable dose (MET-S, N = 138), or on a decreasing dose (MET-D, N = 85) of metformin.

RESULTS

Preoperatively, lactate levels were similar in patients on metformin (1.8 ± 0.05 mmol/L) and those not on metformin (1.7 ± 0.08 mmol/L), P = 0.21. Three months postoperatively, lactate levels had decreased in all groups (P < 0.001) to 1.3 ± 0.07 (SE), 1.4 ± 0.05, and 1.2 ± 0.05 mmol/l in MET-0, MET-S, and MET-D, respectively. Lactate levels differed between the groups (P = 0.03), with the lowest level in MET-D. The number of patients with hyperlactatemia (lactate > 2 mmol/l) decreased from 31 to 14%, from 22 to 8.6%, and from 26 to 4.7% in MET-S, MET-0, and MET-D, respectively.

CONCLUSION

Mild hyperlactatemia (lactate > 2 mmol/l) is common in morbidly obese patients with T2DM. It is probably related to increase lactate production by adipocytes. Lactate levels decreased after RYGB-induced weight loss, irrespective of the use of metformin. We therefore conclude that there is no need for routinely lowering of the metformin dose after uncomplicated RYGB surgery, as long as normal renal function is preserved.

Review of Biguanide (Metformin) Toxicity

In the 1920s, guanidine, the active component of Galega officinalis, was shown to lower glucose levels and used to synthesize several antidiabetic compounds. Metformin (1,1 dimethylbiguanide) is the most well-known and currently the only marketed biguanide in the United States, United Kingdom, Canada, and Australia for the treatment of non-insulin-dependent diabetes mellitus. Although phenformin was removed from the US market in the 1970s, it is still available around the world and can be found in unregulated herbal supplements. Adverse events associated with therapeutic use of biguanides include gastrointestinal upset, vitamin B₁₂ deficiency, and hemolytic anemia. Although the incidence is low, metformin toxicity can lead to hyperlactatemia and metabolic acidosis. Since metformin is predominantly eliminated from the body by the kidneys, toxicity can occur when metformin accumulates due to poor clearance from renal insufficiency or in the overdose setting. The dominant source of metabolic acidosis associated with hyperlactatemia in metformin toxicity is the rapid cytosolic adenosine triphosphate (ATP) turnover when complex I is inhibited and oxidative phosphorylation cannot adequately recycle the vast quantity of H+ from ATP hydrolysis. Although metabolic acidosis and hyperlactatemia are markers of metformin toxicity, the degree of hyperlactatemia and severity of acidemia have not been shown to be of prognostic value. Regardless of the etiology of toxicity, treatment should include supportive care and consideration for adjunct therapies such as gastrointestinal decontamination, glucose and insulin, alkalinization, extracorporeal techniques to reduce metformin body burden, and metabolic rescue.

Identifying prevalence and risk factors for metformin non-persistence: a retrospective cohort study using an electronic health record

OBJECTIVES

Non-persistence may be a significant barrier to the use of metformin. Our objective was to assess reasons for metformin non-persistence, and whether initial metformin dosing or use of extended release (ER) formulations affect persistence to metformin therapy.

DESIGN

Retrospective cohort study.

SETTING

Electronic health record data from a network of urban academic practices.

PARTICIPANTS

The cohort was restricted to individuals receiving a metformin prescription between 2009/1/1 and 2015/9/31, under care for at least 6 months before the first prescription of metformin. The cohort was further restricted to patients with no evidence of any antihyperglycaemic agent use prior to the index date, an haemoglobin A1c measured within 1 month prior to or 1 week after the index date, at least 6 months of follow-up, and with the initial metformin prescription originating in either a general medicine or endocrinology clinic.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcome measure was early non-persistence, as defined by the absence of further prescriptions for metformin after the first 90 days of follow-up.

RESULTS

The final cohort consisted of 1259 eligible individuals. The overall rate of early non-persistence was 20.3%. Initial use of ER and low starting dose metformin were associated with significantly lower rates of reported side effects and non-persistence, but after multivariable analysis, only use of low starting doses was independently associated with improved persistence (adjusted OR 0.54, 95% CI 0.37 to 0.76, for comparison of 500 mg daily dose or less to all higher doses).

CONCLUSIONS

These data support the routine prescribing of low starting doses of metformin as a tool to improve persistence. In this study setting, many providers routinely used ER metformin as an initial treatment; while this practice may have benefits, it deserves more rigorous study to assess whether increased costs are justified.

Trypsin-Treated β-Lactoglobulin Improves Glucose Tolerance in C57BL/6 Mice by Enhancing AMPK Activation and Glucose Uptake in Hepatocytes

It was reported that trypsin-treated β-lactoglobulin (β-LG) had a glucose-lowering effect in the oral glucose tolerance test (OGTT) in mice and a dipeptidyl peptidase-4 (DPP-4) inhibition activity in vitro. However, whether trypsin-treated β-LG improves glucose tolerance by inhibiting DPP-4 in vivo has not yet been examined, and the mechanism of the glucose-lowering effect of trypsin-treated β-LG is thus unclear. Here we investigated the detailed mechanism underlying the glucose tolerance effect of trypsin-treated β-LG. The oral administration of trypsin-treated β-LG significantly decreased the blood glucose concentrations in both the OGTT and an intraperitoneal glucose tolerance test (IPGTT). However, trypsin-treated β-LG did not increase the insulin secretion after glucose loading. Trypsin-treated β-LG potently increased the level of phosphorylated AMP-activated protein kinase (AMPK) in human hepatocellular carcinoma (HepG2) cells and in mice hepatocytes. Moreover, trypsin-treated β-LG significantly enhanced glucose uptake into the HepG2 cells. These results indicate that trypsin-treated β-LG decreases blood glucose levels after glucose loading by upregulating AMPK activation and glucose uptake in the liver, which could contribute to the reduction of postprandial hyperglycemia.

Flos Lonicera Combined with Metformin Ameliorates Hepatosteatosis and Glucose Intolerance in Association with Gut Microbiota Modulation

The gut microbiota is important in energy contribution, metabolism and immune modulation, and compositional disruption of the gut microbiota population is closely associated with chronic metabolic diseases like type 2 diabetes (T2D) and non-alcoholic fatty liver disease (NAFLD). Metformin (MET) and Flos Lonicera (FL) are common treatments for metabolic diseases in Western and Oriental medicinal fields. We evaluated the effect of treatment with FL and MET in combination on hepatosteatosis, glucose tolerance, and gut microbial composition. FL and MET were administered to Otsuka Long-Evans Tokushima Fatty (OLETF) rats, an animal model of genetic T2D and NAFLD. The FL+MET treatment reduced liver weight, serum cholesterol, insulin resistance, and hepatic MDA level and modulated the gut microbial composition. More specifically, the genera of Prevotella and Lactobacillus were negatively associated with the body and liver weights, hepatic TG and TC content, and serum insulin level. However, the relative abundance of these genera decreased in response to the FL+MET treatment. Interestingly, pathway prediction data revealed that the FL+MET treatment attenuated lipopolysaccharide-related pathways, in keeping with the decrease in serum and fecal endotoxin levels. FL and MET in combination exerts a synergistic effect on the improvement of hepatosteatosis and insulin sensitivity in OLETF rats, and modulates gut microbiota in association with the effect.

Controversy of oral hypoglycemic agents in type 2 diabetes mellitus: Novel move towards combination therapies

AIM

As diabetes mellitus is multi-factorial disease, use of several oral hypoglycemic agents (OHAs) is the main stay of pharmacological treatment. The treatment has become more challenging and controversial as OHAs are heterogeneous in their mode of action that causes unwanted side effects. Complementary approaches such as use of medicinal plants and dietary polyunsaturated fatty acids (PUFA) with hypoglycemic and hypolipidemic activities are therefore imperative. A vast literature has independently documented the effects of OHAs, medicinal plants and PUFA for management of diabetes. In the present article, we have reviewed the current literature to describe the effects of commonly used OHAs, their mechanisms of action and reported controversies. The antidiabetic potential of herbs and/or formulations and omega-3 PUFA with its potential benefits and mode of action is also discussed.

METHODS

PUBMED, MEDLINE, Cochrane Library etc., were searched for relevant articles using appropriate terms (until February 2015). Human and animal studies were selected for the review. Data extraction was carried out by one author and checked by second author.

RESULTS

There is still controversy over the safety profile of OHAs. Medicinal herbs with hypoglycemic activities are increasingly sought because of its natural origin, active constituents and minimal side effects. The current literature suggests that supplementation with PUFA improves macro- and microvascular complications.

CONCLUSION

There is a need for best possible individualized treatment based on variations in biochemical parameters with combinational therapy of nutritional/herbal supplementations. Such a combination may be helpful for better management of diabetes and its complications.

Metformin: clinical use in type 2 diabetes

Metformin is one of the most popular oral glucose-lowering medications, widely considered to be the optimal initial therapy for patients with type 2 diabetes mellitus. Interestingly, there still remains controversy regarding the drug's precise mechanism of action, which is thought to involve a reduction in hepatic glucose production. It is now recommended as first-line treatment in various guidelines, including that of the EASD and ADA. Its favoured status lies in its efficacy, low cost, weight neutrality and good safety profile. Other benefits have also been described, including improvements in certain lipids, inflammatory markers, and a reduction in cardiovascular events, apparently independent from the drug's glucose-lowering effect. Data have emerged questioning the previous reluctance to use this agent in those with mild to moderate chronic kidney disease. Regulations guiding its use in patients with stable, modest renal dysfunction have, as a result, become more lenient in recent years. With no long-term studies comparing it against newer glucose-lowering drugs, some of which have more robust evidence for cardioprotection, metformin's established role as 'foundation therapy' in type 2 diabetes may justifiably be challenged.

"Metformin-resistant" folic acid producing probiotics or folic acid against metformin's adverse effects like diarrhea

Metformin, first line medication in the treatment of type2 diabetes by millions of patients worldwide, causes gastrointestinal adverse effects (i.e. diarrhea) in approximately 30% of patients, frequently leading to discontinuation. Interestingly, metformin was reported to increase life span in a microscopic worm, Caenorhabditis elegans, by decreasing folate and methionine production of bacteria that this worm uses as a food source. Metformin can be expected to have a similar effect on some microorganisms of human gut microbiota. This can disturb the balance of gut microbiota and cause gastrointestinal adverse effects by altering folate production of some types of bacteria and suppress their growth. Metformin resistant probiotics can be discovered or generated by artificial evolution/selection, and used to prevent these adverse effects. These patients can also be managed with folate supplementation.

Gastrointestinal Complications of Obesity

Obesity usually is associated with morbidity related to diabetes mellitus and cardiovascular diseases. However, there are many gastrointestinal and hepatic diseases for which obesity is the direct cause (eg, nonalcoholic fatty liver disease) or is a significant risk factor, such as reflux esophagitis and gallstones. When obesity is a risk factor, it may interact with other mechanisms and result in earlier presentation or complicated diseases. There are increased odds ratios or relative risks of several gastrointestinal complications of obesity: gastroesophageal reflux disease, erosive esophagitis, Barrett's esophagus, esophageal adenocarcinoma, erosive gastritis, gastric cancer, diarrhea, colonic diverticular disease, polyps, cancer, liver disease including nonalcoholic fatty liver disease, cirrhosis, hepatocellular carcinoma, gallstones, acute pancreatitis, and pancreatic cancer. Gastroenterologists are uniquely poised to participate in the multidisciplinary management of obesity as physicians caring for people with obesity-related diseases, in addition to their expertise in nutrition and endoscopic interventions.

Evaluation of the concurrent use of dolutegravir and metformin in human immunodeficiency virus-infected patients

An analysis of the interaction between dolutegravir and metformin was conducted in the HIV ambulatory clinic setting. This was a multicenter, retrospective case series evaluating adult, HIV-infected patients concurrently prescribed dolutegravir and metformin. Historical electronic medical records were utilized to collect case-specific data. Laboratory parameters including serum creatinine (SCr), hemoglobin A1c (HgbA1c), plasma HIV RNA, CD4 cell count, and lactate were reviewed. Adverse drug reactions were assessed using patient-reported gastrointestinal intolerance and hypoglycemic symptoms. Metformin dose reduction or discontinuation was also recorded. Nineteen patients identified as concurrently taking metformin and dolutegravir were included. Eighteen patients were on metformin prior to dolutegravir initiation, with 13 having received metformin for at least six months prior to dolutegravir. At the time of dolutegravir initiation, one patient had a preemptive metformin dose reduction. Seven patients were initiated on dolutegravir with a metformin dose greater than 1000 mg daily. Eleven patients had baseline and three- to six-month follow-up HgbA1c. Of those 11 patients, eight had stable or decreased values. Thirteen of the 19 patients had an increase in SCr, with a median increase of 0.3 mg/dl (0.03-0.43). Gastrointestinal distress (N = 3) and hypoglycemic symptoms (N = 3) were reported in a total of five patients. Adverse drug reactions resulted in metformin dose reduction (N = 2) and/or discontinuation (N = 2). There were no reported cases of lactic acidosis. Providers concurrently prescribing dolutegravir and metformin should be aware of potential consequences with this combination and may consider an empiric metformin dose reduction to prevent intolerable adverse drug reactions.

Dyspepsia and constipation in patients with schizophrenia spectrum disorders

Constipation and dyspepsia are disturbing gastrointestinal symptoms that are often ignored in research on physical comorbidities of schizophrenia. The aim was to assess dyspepsia and constipation in a sample of outpatients with schizophrenia spectrum psychoses. A general practitioner performed a thorough physical health check for 275 outpatients and diagnosed constipation and dyspepsia. This study assessed the possible contribution of several sociodemographic, lifestyle, and clinical variables to constipation and dyspepsia using logistic regression analysis. This study also assessed whether these symptoms were associated with abnormal laboratory findings. The prevalence of constipation was 31.3%, and of dyspepsia 23.6%. Paracetamol (OR =3.07, 95% CI =1.34-7.02) and clozapine use (OR =5.48, 95% CI =2.75-10.90), older age (OR =1.04, 95% CI =1.01-1.06), and living in sheltered housing (OR =2.49, 95% CI =1.16-5.33) were risk factors for constipation. For dyspepsia the risk factors were female sex (OR =2.10, 95% CI =1.15-3.83), non-steroidal anti-inflammatory drugs (OR =2.47, 95% CI =1.13-5.39), and diabetes medication (OR =2.42, 95% CI =1.12-5.25). Patients with dyspepsia had lower haemoglobin and haematocrit and higher glucose values than those without dyspepsia. Patients with constipation had lower thrombocyte values than patients without constipation. However, these findings were explained by factors pre-disposing to constipation and dyspepsia. Clozapine use markedly increases the risk of constipation and may lead to life-threatening complications. In addition, analgesics and diabetes medication were related to gastrointestinal symptoms. These medications and their association to gastrointestinal symptoms should be kept in mind when treating patients with schizophrenia.

Targeting hepatic glucose metabolism in the treatment of type 2 diabetes

Type 2 diabetes mellitus is characterized by the dysregulation of glucose homeostasis, resulting in hyperglycaemia. Although current diabetes treatments have exhibited some success in lowering blood glucose levels, their effect is not always sustained and their use may be associated with undesirable side effects, such as hypoglycaemia. Novel antidiabetic drugs, which may be used in combination with existing therapies, are therefore needed. The potential of specifically targeting the liver to normalize blood glucose levels has not been fully exploited. Here, we review the molecular mechanisms controlling hepatic gluconeogenesis and glycogen storage, and assess the prospect of therapeutically targeting associated pathways to treat type 2 diabetes.

Clinical Considerations for Use of Initial Combination Therapy in Type 2 Diabetes

Type 2 diabetes is a progressive disorder characterized by increasing hyperglycemia and the need to gradually intensify therapy in order to achieve and maintain glycemic control. Early initiation of combination therapy has been proposed as an approach to achieve glycemic goals earlier and delay the deterioration of glycemic control and with possible better preservation of β-cell function. We discuss in this article the pros and cons of this approach, focusing on individuals with HbA1c at diagnosis of 7.5-9.0%, where difference of opinion still exists on management. Initial combination therapy is proposed to lead to better and faster achievement of glycemic targets versus monotherapy and to impede clinical inertia and may possibly slow the deterioration of β-cell function. However, treating patients with sequential therapy is proposed to allow one to fully assess the efficacy and risk-to-benefit ratio of each drug as it is added. Furthermore, there is no evidence to support that rapid addition and titration of medications according to the glycemic profile achieved are inferior to initial combination therapy if glycemic targets are attained in a timely manner. Initial combination therapy is argued to postpone clinical inertia to the next decision point but does not eliminate it. Additionally, it may have been the agents chosen and not the timing of their initiation that led to improved β-cell function in the studies of initial combination therapy, and there are no data currently comparing use of the same drugs initiated simultaneously or sequentially. Heightened awareness of providers, individualization of therapy and setting, and reaching glycemic targets remain the mainstays of care.

Effects of body mass index or dosage on gastrointestinal disorders associated with extended-release metformin in type 2 diabetes: Sub-analysis of a Phase IV open-label trial in Chinese patients

AIM

To determine whether gastrointestinal (GI) tolerability of metformin monotherapy varies according to baseline BMI or at doses >1500mg/day in patients newly diagnosed with type 2 diabetes.

METHODS

We performed a sub-analysis of the safety population from a prospective, multicenter, Phase IV open-label study in which 371 Chinese patients with type 2 diabetes received extended-release metformin monotherapy for 16 weeks. The incidence, severity and duration of GI adverse events (AEs) were compared between normal-weight (BMI<25kg/m(2), n=155) and overweight/obese (BMI≥25kg/m(2), n=216) patients. The primary objective was to determine whether baseline BMI affect the incidence, severity and duration of GI AEs, using Fisher's exact test and Student's t-test. Secondary objectives were to compare these factors according to final metformin dose (≤1500mg/day versus 2000mg/day).

RESULTS

The proportion of patients who reported ≥1 GI AE did not differ significantly between BMI groups (25.2% of the normal-weight group versus 21.3% of the overweight/obese group; p=0.3840). Patients who reported GI AEs in the two BMI groups experienced similar GI AE severity (p=0.5410), mean duration (p=0.3572) and duration distribution (p=0.1347). There was no significant difference in GI AE severity and duration between metformin dosage groups (≤1500mg/day versus 2000mg/day).

CONCLUSIONS

Newly-diagnosed Chinese type 2 diabetes patients of normal weight are no more likely than overweight/obese patients to suffer from increased incidence rates, severity or duration of GI AEs when treated with first-line extended-release metformin monotherapy. Doses of 2000mg/day did not increase the severity or duration of GI AEs.

Organic cation transporter 1 variants and gastrointestinal side effects of metformin in patients with Type 2 diabetes

AIMS

Metformin is the most widely used oral anti-diabetes agent and has considerable benefits over other therapies, yet 20-30% of people develop gastrointestinal side effects, and 5% are unable to tolerate metformin due to the severity of these side effects. The mechanism for gastrointestinal side effects and their considerable inter-individual variability is unclear. We have recently shown the association between organic cation transporter 1 (OCT1) variants and severe intolerance to metformin in people with Type 2 diabetes. The aim of this study was to explore the association of OCT1 reduced-function polymorphisms with common metformin-induced gastrointestinal side effects in Type 2 diabetes.

METHODS

This prospective observational cohort study included 92 patients with newly diagnosed Type 2 diabetes, incident users of metformin. Patients were genotyped for two common loss-of-function variants in the OCT1 gene (SLC22A1): R61C (rs12208357) and M420del (rs72552763). The association of OCT1 reduced-function alleles with gastrointestinal side effects was analysed using logistic regression.

RESULTS

Forty-three patients (47%) experienced gastrointestinal adverse effects in the first 6 months of metformin treatment. Interestingly, the number of OCT1 reduced-function alleles was significantly associated with over two-fold higher odds of the common metformin-induced gastrointestinal side effects (odds ratio = 2.31, 95% confidence interval 1.07-5.01, P = 0.034).

CONCLUSIONS

In conclusion, we showed for the first time the association between OCT1 variants and common metformin-induced gastrointestinal side effects. These results confirm recent findings related to the role of OCT1 in severe metformin intolerance, and suggest that high inter-individual variability in mild/moderate and severe gastrointestinal intolerance share a common underlying mechanism. These data could contribute to more personalized and safer metformin treatment.

Metformin Changes the Relationship between Blood Monocyte Toll-Like Receptor 4 Levels and Nonalcoholic Fatty Liver Disease-Ex Vivo Studies

BACKGROUND

Toll-like receptor 4 (TLR4) contributes to the development of NAFLD (nonalcoholic fatty liver disease) and MetS (metabolic syndrome). It is unclear whether anti-diabetic metformin affects TLR4 expression on blood monocytes, thereby protecting or improving inflammatory parameters. Therefore, we investigated TLR4 in patients with NAFLD meeting different sets of MetS criteria and linked the results with the disease burden.

METHODS

70 subjects were characterized and divided into three groups: (I) healthy individuals, (II) nonobese with NAFLD and without MetS, and (III) prediabetic, obese with NAFLD and MetS. We determined the concentrations of IL-1β, IL-6, TNFα, and monocyte TLR4 levels in fresh blood as well as in blood cultures with or without metformin supplementation.

RESULTS

The characteristics of the study groups revealed a significant association between NAFLD and BMI, MetS and inflammatory parameters, and TLR4. In ex vivo studies, 100 μM of metformin decreased the TLR4 level by 19.9% (II group) or by 35% (III group) as well as IL-1β and TNFα production. A stepwise multiple regression analysis highlighted a strong effect of metformin on attenuation of the link between TLR4 and NAFLD, and TNFα.

CONCLUSION

We concluded that, by attenuation of the blood monocyte TLR4 level, metformin reduced their inflammatory potential-critical after recruitment these cells into liver. However, this finding should be confirmed after in vivo metformin administration.

Repurposing metformin: an old drug with new tricks in its binding pockets

Improvements in healthcare and nutrition have generated remarkable increases in life expectancy worldwide. This is one of the greatest achievements of the modern world yet it also presents a grave challenge: as more people survive into later life, more also experience the diseases of old age, including type 2 diabetes (T2D), cardiovascular disease (CVD) and cancer. Developing new ways to improve health in the elderly is therefore a top priority for biomedical research. Although our understanding of the molecular basis of these morbidities has advanced rapidly, effective novel treatments are still lacking. Alternative drug development strategies are now being explored, such as the repurposing of existing drugs used to treat other diseases. This can save a considerable amount of time and money since the pharmacokinetics, pharmacodynamics and safety profiles of these drugs are already established, effectively enabling preclinical studies to be bypassed. Metformin is one such drug currently being investigated for novel applications. The present review provides a thorough and detailed account of our current understanding of the molecular pharmacology and signalling mechanisms underlying biguanide-protein interactions. It also focuses on the key role of the microbiota in regulating age-associated morbidities and a potential role for metformin to modulate its function. Research in this area holds the key to solving many of the mysteries of our current understanding of drug action and concerted effects to provide sustained and long-life health.

Multimorbidities and Overprescription of Proton Pump Inhibitors in Older Patients

OBJECTIVES

To determine whether there is an association between overprescription of proton pump inhibitors (PPIs) and multimorbidities in older patients.

DESIGN

Multicenter prospective study.

SETTING

Acute geriatric medicine at the University Hospital of Nantes and the Hospital of Saint-Nazaire.

PARTICIPANTS

Older patients aged 75 and over hospitalized in acute geriatric medicine.

MEASUREMENTS

Older patients in acute geriatric medicine who received proton pump inhibitors. Variables studied were individual multimorbidities, the burden of multimorbidity evaluated by the Cumulative Illness Rating Scale, age, sex, type of residence (living in nursing home or not), functional abilities (Lawton and Katz scales), nutritional status (Body Mass Index), and the type of concomitant medications (antiaggregant, corticosteroids', or anticoagulants).

RESULTS

Overprescription of proton pump inhibitors was found in 73.9% older patients. In the full model, cardiac diseases (odds ratio [OR] = 4.17, p = 0.010), metabolic diseases (OR = 2.14, p = 0.042) and corticosteroids (OR = 5.39, p = 0.028) were significantly associated with overprescription of proton pump inhibitors. Esogastric diseases (OR = 0.49, p = 0.033) were negatively associated with overprescription of proton pump inhibitors.

CONCLUSION

Cardiac diseases and metabolic diseases were significantly associated with overprescription of proton pump inhibitors.

Prediction and validation of enzyme and transporter off-targets for metformin

Metformin, an established first-line treatment for patients with type 2 diabetes, has been associated with gastrointestinal (GI) adverse effects that limit its use. Histamine and serotonin have potent effects on the GI tract. The effects of metformin on histamine and serotonin uptake were evaluated in cell lines overexpressing several amine transporters (OCT1, OCT3 and SERT). Metformin inhibited histamine and serotonin uptake by OCT1, OCT3 and SERT in a dose-dependent manner, with OCT1-mediated amine uptake being most potently inhibited (IC50 = 1.5 mM). A chemoinformatics-based method known as Similarity Ensemble Approach predicted diamine oxidase (DAO) as an additional intestinal target of metformin, with an E-value of 7.4 × 10(-5). Inhibition of DAO was experimentally validated using a spectrophotometric assay with putrescine as the substrate. The Ki of metformin for DAO was measured to be 8.6 ± 3.1 mM. In this study, we found that metformin inhibited intestinal amine transporters and DAO at concentrations that may be achieved in the intestine after therapeutic doses. Further studies are warranted to determine the relevance of these interactions to the adverse effects of metformin on the gastrointestinal tract.

Efficacy and tolerability of vildagliptin as first line treatment in patients with diabetes type 2 in an outpatient setting

Background

Inhibitors of dipeptidyl-peptidase IV are recommended as second-line therapy in type 2 diabetes (DT2), but data, as a first-line treatment in everyday clinical practice are scarce. To address this issue we conducted a 12-month, clinical study in an outpatient setting, using vildagliptin as the first-line treatment.

Methods

Ninety-one drug naïve patients with DT2 started with vildagliptin monotherapy (100 mg daily) for 4 months and were scheduled to regular 4-monthly visits for 1 year. Patients received add-on treatment with metformin or metformin and glimepiride according to their glycosylated hemoglobin (HbA1c) at each study-visit.

Results

HbA1c was significantly decreased with vildagliptin monotherapy from 8.16 % ± 1.60 to 7.52 % ± 1.60, p < 0.001. Only 39 % of the patients achieved the target of HbA1c ≤ 7.0 % at the end of the 4th month. Mean change in HbA1c was significantly correlated with baseline HbA1c values (r = −0.51, p < 0.001). At the end of the study only 35 % of the patients remained on vildagliptin monotherapy while the rest required add-on treatment with metformin or metformin and sulfonylurea.

Conclusions

Vildagliptin is well tolerated either as monotherapy or in combination but the majority of patients require add-on therapy shortly after the beginning of treatment.

Addition of a Gastrointestinal Microbiome Modulator to Metformin Improves Metformin Tolerance and Fasting Glucose Levels

BACKGROUND

Adverse effects of metformin are primarily related to gastrointestinal (GI) intolerance that could limit titration to an efficacious dose or cause discontinuation of the medication. Because some metformin side effects may be attributable to shifts in the GI microbiome, we tested whether a GI microbiome modulator (GIMM) used in combination with metformin would ameliorate the GI symptoms.

METHODS

A 2-period crossover study design was used with 2 treatment sequences, either placebo in period 1 followed by GIMM in period 2 or vice versa. Study periods lasted for 2 weeks, with a 2-week washout period between. During the first week, type 2 diabetes patients (T2D) who experienced metformin GI intolerance took 500 mg metformin along with their assigned NM504 (GIMM) or placebo treatment with breakfast and with dinner. In the second week, the 10 subjects took 500 mg metformin (t.i.d.), with GIMM or placebo consumed with the first and third daily metformin doses. Subjects were permitted to discontinue metformin dosing if it became intolerable.

RESULTS

The combination of metformin and GIMM treatment produced a significantly better tolerance score to metformin than the placebo combination (6.78 ± 0.65 [mean ± SEM] versus 4.45 ± 0.69, P = .0006). Mean fasting glucose levels were significantly (P < .02) lower with the metformin-GIMM combination (121.3 ± 7.8 mg/dl) than with metformin-placebo (151.9 ± 7.8 mg/dl).

CONCLUSION

Combining a GI microbiome modulator with metformin might allow the greater use of metformin in T2D patients and improve treatment of the disease.

Association of Organic Cation Transporter 1 With Intolerance to Metformin in Type 2 Diabetes: A GoDARTS Study

Metformin is the most widely prescribed medication for the treatment of type 2 diabetes (T2D). However, gastrointestinal (GI) side effects develop in ~25% of patients treated with metformin, leading to the discontinuation of therapy in ~5% of cases. We hypothesized that reduced transport of metformin via organic cation transporter 1 (OCT1) could increase metformin concentration in the intestine, leading to increased risk of severe GI side effects and drug discontinuation. We compared the phenotype, carriage of reduced-function OCT1 variants, and concomitant prescribing of drugs known to inhibit OCT1 transport in 251 intolerant and 1,915 fully metformin-tolerant T2D patients. We showed that women and older people were more likely to be intolerant to metformin. Concomitant use of medications, known to inhibit OCT1 activity, was associated with intolerance (odds ratio [OR] 1.63 [95% CI 1.22-2.17], P = 0.001) as was carriage of two reduced-function OCT1 alleles compared with carriage of one or no deficient allele (OR 2.41 [95% CI 1.48-3.93], P < 0.001). Intolerance was over four times more likely to develop (OR 4.13 [95% CI 2.09-8.16], P < 0.001) in individuals with two reduced-function OCT1 alleles who were treated with OCT1 inhibitors. Our results suggest that reduced OCT1 transport is an important determinant of metformin intolerance.

A multicomponent nutrient bar promotes weight loss and improves dyslipidemia and insulin resistance in the overweight/obese: chronic inflammation blunts these improvements

This study determined if twice-daily consumption of a nutrient-dense bar intended to fill gaps in Western diets, without other dietary/lifestyle requirements, favorably shifted metabolic/anthropometric indicators of dysregulation in a healthy direction. Three 8-wk clinical trials in 43 healthy lean and overweight/obese (OW/OB) adults, who served as their own controls, were pooled for analysis. In less inflamed OW/OB [high-sensitivity C-reactive protein (hsCRP) <1.5], statistically significant decreases occurred in weight (-1.1 ± 0.5 kg), waist circumference (-3.1 ± 1.4 cm), diastolic blood pressure (-4.1 ± 1.6 mmHg), heart rate [HR; -4.0 ± 1.7 beats per minute (bpm)], triglycerides (-72 ± 38.2 mg/dl), insulin resistance (homeostatic model of insulin resistance) (-0.72 ± 0.3), and insulin (-2.8 ± 1.3 mU/L); an increase in HDL-2b (+303 ± 116 nM) and realignment of LDL lipid subfractions toward a less atherogenic profile [decreased small LDL IIIb (-44 ± 23.5 nM), LDL IIIa (-99 ± 43.7 nM), and increased large LDL I (+66 ± 28.0 nM)]. In the more inflamed OW/OB (hsCRP >1.5), inflammation was reduced at 2 wk (-0.66 mg/L), and HR at 8 wk (-3.4 ± 1.3 bpm). The large HDL subfraction (10.5-14.5 nm) increased at 8 wk (+346 ± 126 nM). Metabolic improvements were also observed in lean participants. Thus, favorable changes in measures of cardiovascular health, insulin resistance, inflammation, and obesity were initiated within 8 wk in the OW/OB by replacing deficiencies in Western diets without requiring other dietary or lifestyle modifications; chronic inflammation blunted most improvements.

Drug-induced gastrointestinal disorders

Drug-induced gastrointestinal disorders can mimic conditions, such as inflammatory bowel disease (IBD) and irritable bowel syndrome (IBS) and, hence, recognition can prevent unnecessary investigations and treatment. While the knowledge and awareness relating to the adverse gastrointestinal effects of some medications, such as non-steroidal anti-inflammatory drugs are well established, other commonly prescribed drugs, such as antipsychotics, antidepressants and metformin are less well understood and warrant further study. This review attempts to integrate recent information regarding adverse drug reactions and place this in a useful clinical context.

Initial combination of empagliflozin and linagliptin in subjects with type 2 diabetes

OBJECTIVE

To evaluate the efficacy and safety of empagliflozin/linagliptin in subjects with type 2 diabetes.

RESEARCH DESIGN AND METHODS

Subjects not receiving antidiabetes therapy for ≥12 weeks were randomized to empagliflozin 25 mg/linagliptin 5 mg (n = 137), empagliflozin 10 mg/linagliptin 5 mg (n = 136), empagliflozin 25 mg (n = 135), empagliflozin 10 mg (n = 134), or linagliptin 5 mg (n = 135) for 52 weeks. The primary end point was change from baseline in HbA1c at week 24.

RESULTS

Mean HbA1c at baseline was 7.99-8.05% (64 mmol/mol). At week 24, adjusted mean (SE) changes from baseline in HbA1c with empagliflozin 25 mg/linagliptin 5 mg, empagliflozin 10 mg/linagliptin 5 mg, empagliflozin 25 mg, empagliflozin 10 mg, and linagliptin 5 mg were -1.08 (0.06)% (-11.8 [0.7] mmol/mol), -1.24 (0.06)% (-13.6 [0.7] mmol/mol), -0.95 (0.06)% (-10.4 [0.7] mmol/mol), -0.83 (0.06)% (-9.1 [0.7] mmol/mol), and -0.67 (0.06)% (-7.3 [0.7] mmol/mol), respectively. Reductions in HbA1c were significantly greater for empagliflozin 25 mg/linagliptin 5 mg compared with linagliptin 5 mg (P < 0.001) but not compared with empagliflozin 25 mg and were significantly greater for empagliflozin 10 mg/linagliptin 5 mg compared with the individual components (P < 0.001 for both). At week 24, 55.4%, 62.3%, 41.5%, 38.8%, and 32.3% of subjects with baseline HbA1c ≥7% (≥53 mmol/mol) reached HbA1c <7% with empagliflozin 25 mg/linagliptin 5 mg, empagliflozin 10 mg/linagliptin 5 mg, empagliflozin 25 mg, empagliflozin 10 mg, and linagliptin 5 mg, respectively. Efficacy was maintained at week 52. The proportion of subjects with adverse events (AEs) over 52 weeks was similar across groups (68.9-81.5%), with no confirmed hypoglycemic AEs.

CONCLUSIONS

Reductions from baseline in HbA1c with empagliflozin/linagliptin were significantly different versus linagliptin and empagliflozin 10 mg but not versus empagliflozin 25 mg. Empagliflozin/linagliptin was well tolerated.

Helicobacter pylori infection decreases metformin tolerance in patients with type 2 diabetes mellitus

AIM

This study assessed whether Helicobacter pylori infection could influence metformin tolerance in patients with type 2 diabetes mellitus.

SUBJECTS AND METHODS

Demographic, anthropometric, ultrasound, and laboratory data were obtained from 415 metformin-naive patients with diabetes. H. pylori infection was assessed based on the (13)C-labeled urea breath test ((13)C-UBT). The study duration was 4 weeks, and all subjects started metformin from 500 mg/day to 1,500 mg/day progressively. Gastrointestinal side effects were assessed each week, and the metformin doses were adjusted by the compliance. Gastrointestinal side effects were compared between H. pylori-positive and -negative groups.

RESULTS

According to the (13)C-UBT results, 220 patients were categorized as H. pylori negative versus 195 as H. pylori positive. At baseline, the scoring of gastrointestinal symptoms showed no statistical difference between the two groups. After 4 weeks, for gastrointestinal symptoms such as abdominal pain, nausea, bloating, and anorexia, the respective percentages in H. pylori-positive and -negative subjects were 44.6% versus 21.8% (P < 0.01), 20.0% versus 9.6% (P < 0.01), 47.7% versus 23.2% (P < 0.01), and 32.8% versus 12.3% (P < 0.01). The final metformin dose was 951.28 ± 661.1 mg in H. pylori-positive subjects, significantly less than that in H. pylori-negative subjects (1,209.09 ± 522.91 mg) (P < 0.01). On multivariate analysis, female gender, H. pylori infection, body mass index, triglycerides, age, and low-density lipoprotein-cholesterol were the independent parameters associated with any gastrointestinal symptoms.

CONCLUSIONS

Patients with diabetes having H. pylori infection demonstrated more gastrointestinal side effects than those without H. pylori infection after taking metformin. Furthermore, female gender, H. pylori infection, body mass index, triglycerides, age, and low-density lipoprotein-cholesterol are independent determinants of metformin's side effects.

Oral antihyperglycemic treatment options for type 2 diabetes mellitus

Table 3 provides an overview of the oral antihyperglycemic drugs reviewed in this article. A 2011 meta-analysis by Bennett and colleagues found low or insufficient quality of evidence favoring an initial choice of metformin, SUs, glinides, TZDs, or (table see text) DPP-4 inhibitors (alpha-glucosidase inhibitors, bromocriptine mesylate, and SGLT2 inhibitors were not included in this meta-analysis) with regard to the outcomes measures of all-cause mortality, cardiovascular events and mortality, and incidence of microvascular disease (retinopathy, nephropathy, and neuropathy) in previously healthy individuals with newly diagnosed T2DM. Likewise, the Bennett and colleagues meta-analysis judged these drugs to be of roughly equal efficacy with regard to reduction of HbA1c (1%–1.6%) from the pretreatment baseline. The ADOPT clinical trial of 3 different and, at the time, popular, oral monotherapies for T2DM provides support for the consensus recommendation of metformin as first-line therapy. The ADOPT trial showed slightly superior HbA1c reduction for rosiglitazone compared with metformin, which was in turn superior to glyburide. However, significant adverse events, including edema, weight gain, and fractures, were more common in the rosiglitazone-treated patients. The implication of this trial is that the combination of low cost, low risk, minimal adverse effects, and efficacy of metformin justifies use of this agent as the cornerstone of oral drug treatment of T2DM. Judicious use of metformin in groups formerly thought to be at high risk for lactic acidosis (ie, those with CHF, chronic kidney disease [eGFR >30 mL/min/1.73 m2], and the elderly) may be associated with mortality benefit rather than increased risk. Secondary and tertiary add-on drug therapy should be individualized based on cost, personal preferences, and overall treatment goals, taking into account the wishes and priorities of the patient.

Risk of diarrhea in patients with type 2 diabetes mellitus treated with sitagliptin: a meta-analysis of 30 randomized clinical trials

BACKGROUND

Sitagliptin is an important drug used for diabetes treatment and is used as a monotherapy in diabetic patients. However, there are also reported cases of diarrhea with sitagliptin use. Unfortunately, data concerning the relationship of diarrhea with sitagliptin use in various conditions have yet to be identified. Therefore, the overall incidence and risk of diarrhea with sitagliptin use have not been well defined.

METHODS

We conducted searches on Embase, PubMed, and the Cochrane Library databases for relevant randomized controlled trials. Registered relevant trials at the clinical trials registration website were also searched. Statistical analyses were conducted to calculate the overall incidence, odds ratios, and 95% confidence intervals (CI) by using either random-effects or fixed-effect models according to the heterogeneity of the included studies.

RESULTS

A total of 8,891 subjects with diabetes from 30 randomized clinical trials were included in the meta-analysis. The overall incidence of sitagliptin-associated diarrhea was 4.48% (95% CI: 3.59%-5.58%). Compared with the controls, the use of sitagliptin was not associated with a significantly increased risk of diarrhea with an odds ratio of 1.10 (95% CI: 0.78%-1.55%; P=0.58). No evidence of publication bias was observed.

CONCLUSION

Our study has shown that there is no difference in diarrhea risk between sitagliptin and controlled therapies. Moreover, sitagliptin is not a medicine that potentially increases the risk of diabetic diarrhea. More studies are recommended to further investigate this association.

Higher prevalence of metformin-induced vitamin B12 deficiency in sulfonylurea combination compared with insulin combination in patients with type 2 diabetes: a cross-sectional study

Long-term and high-dose treatment with metformin is known to be associated with vitamin B₁₂ deficiency in patients with type 2 diabetes. We investigated whether the prevalence of B₁₂ deficiency was different in patients treated with different combination of hypoglycemic agents with metformin during the same time period. A total of 394 patients with type 2 diabetes treated with metformin and sulfonylurea (S+M group, n = 299) or metformin and insulin (I+M group, n = 95) were consecutively recruited. The vitamin B₁₂ and folate levels were quantified using the chemiluminescent enzyme immunoassay. Vitamin B₁₂ deficiency was defined as vitamin B₁₂≤300 pg/mL without folate deficiency (folate>4 ng/mL). The mean age of and duration of diabetes in the subjects were 59.4±10.5 years and 12.2±6.7 years, respectively. The mean vitamin B₁₂ level of the total population was 638.0±279.6 pg/mL. The mean serum B₁₂ levels were significantly lower in the S+M group compared with the I+M group (600.0±266.5 vs. 757.7±287.6 pg/mL, P<0.001). The prevalence of vitamin B₁₂ deficiency in the metformin-treated patients was significantly higher in the S+M group compared with the I+M group (17.4% vs. 4.2%, P = 0.001). After adjustment for various factors, such as age, sex, diabetic duration, duration or daily dose of metformin, diabetic complications, and presence of anemia, sulfonylurea use was a significant independent risk factor for B₁₂ deficiency (OR = 4.74, 95% CI 1.41–15.99, P = 0.012). In conclusion, our study demonstrated that patients with type 2 diabetes who were treated with metformin combined with sulfonylurea require clinical attention for vitamin B₁₂ deficiency and regular monitoring of their vitamin B₁₂ levels.

Formulation and Evaluation of Multilayered Tablets of Pioglitazone Hydrochloride and Metformin Hydrochloride

In the treatment of type 2 diabetes mellitus a continuous therapy is required which is a more complex one. As in these patients there may be a defect in both insulin secretion and insulin action exists. Hence, the treatment depends on the pathophysiology and the disease state. In the present study, multilayered tablets of pioglitazone hydrochloride 15 mg and metformin hydrochloride 500 mg were prepared in an attempt for combination therapy for the treatment of type 2 diabetes mellitus. Pioglitazone HCl was formulated as immediate release layer to show immediate action by direct compression method using combination of superdisintegrants, namely, crospovidone and avicel PH 102. Crospovidone at 20% concentration showed good drug release profile at 2 hrs. Metformin HCl was formulated as controlled release layer to prolong the drug action by incorporating hydrophilic polymers such as HPMC K4M by direct compression method and guar gum by wet granulation method in order to sustain the drug release from the tablets and maintain its integrity so as to provide a suitable formulation. The multilayered tablets were prepared after carrying out the optimization of immediate release layer and were evaluated for various precompression and postcompression parameters. Formulation F13 showed 99.97% of pioglitazone release at 2 hrs in 0.1 N HCl and metformin showed 98.81% drug release at 10 hrs of dissolution in 6.8 pH phosphate buffer. The developed formulation is equivalent to innovator product in view of in vitro drug release profile. The results of all these evaluation tests are within the standards. The procedure followed for the formulation of these tablets was found to be reproducible and all the formulations were stable after accelerated stability studies. Hence, multilayered tablets of pioglitazone HCl and metformin HCl can be a better alternative way to conventional dosage forms.