Oral antihyperglycemic therapy for type 2 diabetes mellitus

DIABETES MELLITUS IS A CHRONIC DISEASE that is growing in prevalence worldwide. Pharmacologic therapy is often necessary to achieve optimal glycemic control in the management of diabetes. Orally administered antihyperglycemic agents (OHAs) can be used either alone or in combination with other OHAs or insulin. The number of available OHAs has increased significantly in the last decade, which translates into more therapeutic options and complex decision-making for physicians. This review article is designed to help with these decisions. We review the mechanism of action, efficacy and side effects of the different classes of OHAs (α-glucosidase inhibitors, biguanides, insulin secretagogues, insulin sensitizers and intestinal lipase inhibitor) and discuss the current recommendations for their use.Diabetes mellitus is a chronic disease that is growing in prevalence worldwide.¹ Canadian data from the National Diabetes Surveillance Strategy demonstrate a prevalence of 4.8% among adults, with the vast majority having type 2 diabetes.²With the growing elderly Canadian population, the rising prevalence of obesity and the alarming increase in childhood and adolescent type 2 diabetes, the burden of this disease will continue to grow. Aggressive glycemic control has been demonstrated to decrease microvascular^3,4,5 and perhaps macrovascular^6,7 complications, although the latter claim remains controversial. The Canadian Diabetes Association 2003 Clinical Practice Guidelines for the Prevention and Management of Diabetes in Canada⁸ recommends a target hemoglobin A_1c concentration of 7.0% or less for all patients with diabetes and, for those in whom it can be safely achieved, a target hemoglobin A_1c concentration in the normal range (usually ≤ 6.0%).⁸ Although nonpharmacologic therapy (e.g., diet, exercise and weight loss) remains a critical component in the treatment of diabetes, pharmacologic therapy is often necessary to achieve optimal glycemic control. Orally administered antihyperglycemic agents (OHAs) can be used either alone or in combination with other OHAs or insulin. The number of available OHAs has increased significantly in the last decade, which translates into more therapeutic options and complex decision-making. This article reviews the mechanism of action, efficacy and side effects of each OHA drug class (α-glucosidase inhibitors, biguanides, insulin secretagogues, insulin sensitizers and intestinal lipase inhibitor) and the current recommendations for their use.     

Switching to basal-bolus insulin therapy is effective and safe in long-term type 2 diabetes patients inadequately controlled with other insulin regimens

AimTo assess in standard clinical practice the feasibility, efficacy, and safety of switching patients with long-standing type 2 diabetes (T2DM) and poor or unstable blood glucose control to basal-bolus insulin therapy.Material and methodsThis was a prospective, single center study including 37 patients with T2DM (age 65 ± 8 years, 62.2% men, body mass index 28.8 ± 6.2 kg/m², diabetes duration 18 ± 8 years) with poor or unstable glycemic control, who were switched to a basal-bolus insulin regimen with glargine and rapid-acting insulin analogue at the discretion of their physicians. After a group-structured outpatient diabetes training program, patients were followed in a clinical practice setting for 6 months. Clinical and biochemical variables were collected before switching and at 3 and 6 months.ResultsAfter switching to basal-bolus therapy, glycosylated hemoglobin (HbA1c) decreased from 9 ± 1.2% to 8.1 ± 1.2% (p < 0.001) at 3 months and to 8.0 ± 1.2% at 6 months (p < 0.001) without changing total daily insulin dose. The proportion of patients with HbA1c ≥ 9% decreased from 51% to 13.8% at 3 months and to 18.9% at 6 months respectively. There was a single episode of severe hypoglycemia. No changes were seen in body weight and quality of life. The size of LDL (low density lipoprotein) particles significantly increased at 3 and 6 months, while all other lipid parameters remained unchanged.ConclusionsOur study confirmed that basal-bolus insulin therapy is feasible, effective, and safe in patients with long-standing T2DM, and does not impair their quality of life.     

A randomized,placebo-controlled clinical trial evaluating the safety and efficacy of the once-weekly DPP-4 inhibitor omarigliptin in patients with type 2 diabetes mellitus inadequately controlled by glimepiride and metformin

Background

Type 2 diabetes (T2D) is a progressive disease that often requires a patient to use multiple antihyperglycemic agents to achieve glycemic control with disease progression. Omarigliptin is a once-weekly dipeptidyl peptidase-4 inhibitor. The purpose of this trial was to assess the efficacy and safety of adding omarigliptin to the treatment regimen of patients with T2D inadequately controlled by dual therapy with metformin and glimepiride.

Methods

Patients with T2D and HbA1c ≥7.5% and ≤10.5% while on metformin (≥1500 mg/day) and glimepiride (≥4 mg/day) were randomized to omarigliptin 25 mg once-weekly (N = 154) or placebo (N = 153) for 24 weeks. The primary objective was to assess whether omarigliptin was superior to placebo in reducing HbA1c at Week 24. Secondary objectives were to assess the effects of omarigliptin vs. placebo on FPG and the proportion of subjects attaining HbA1c goals of <7% and <6.5%.

Results

From a mean baseline HbA1c of 8.5% (omarigliptin) and 8.6% (placebo), the least squares (LS) mean change from baseline in HbA1c at Week 24 was ?0.67% in the omarigliptin group and ?0.06% in the placebo group, with a between-group difference (95% CI) of ?0.61% (?0.85, ?0.38). Treatment with omarigliptin resulted in a significantly greater reduction in FPG relative to placebo (LS mean difference [95% CI] -0.9 mmol/L [?1.4, ?0.4]; p < 0.001). The proportion of patients achieving glycemic goals of <7.0% and <6.5% was higher in the omarigliptin group relative to the placebo group. The overall incidences of adverse events (AEs), serious AEs, drug-related AEs and discontinuations were generally similar between treatment groups. The incidence of symptomatic hypoglycemia was 10.5% in the omarigliptin group and 8.5% in the placebo group. Relative to baseline, omarigliptin and placebo treatments were associated with LS mean changes in body weight of ?0.1 kg and ?0.9 kg, respectively.

Conclusion

In patients with T2D and inadequate glycemic control on dual therapy with metformin and glimepiride, compared with placebo, once-weekly omarigliptin provided greater improvement in glycemic control and was generally well tolerated.

Trial registration

ClinicalTrials.gov: NCT01704261, EudraCT Number: 2012-002612-10. Trial Registration Date: October 8, 2012.

     

Cost-effectiveness of self-monitoring of blood glucose in patients with type 2 diabetes mellitus managed without insulin

Background

The benefits of self-monitoring blood glucose levels are unclear in patients with type 2 diabetes mellitus who do not use insulin, but there are considerable costs. We sought to determine the cost effectiveness of self-monitoring for patients with type 2 diabetes not using insulin.

Methods

We performed an incremental cost-effectiveness analysis of the self-monitoring of blood glucose in adults with type 2 diabetes not taking insulin. We used the United Kingdom Prospective Diabetes Study (UKPDS) model to forecast diabetes-related complications, corresponding quality-adjusted life years and costs. Clinical data were obtained from a systematic review comparing self-monitoring with no self-monitoring. Costs and utility decrements were derived from published sources. We performed sensitivity analyses to examine the robustness of the results.

Results

Based on a clinically modest reduction in hemoglobin A_1C of 0.25% (95% confidence interval 0.15–0.36) estimated from the systematic review, the UKPDS model predicted that self-monitoring performed 7 or more times per week reduced the lifetime incidence of diabetes-related complications compared with no self-monitoring, albeit at a higher cost (incremental cost per quality-adjusted life year $113 643). The results were largely unchanged in the sensitivity analysis, although the incremental cost per quality-adjusted life year fell within widely cited cost-effectiveness thresholds when testing frequency or the price per test strip was substantially reduced from the current levels.

Interpretation

For most patients with type 2 diabetes not using insulin, use of blood glucose test strips for frequent self-monitoring (≥ 7 times per week) is unlikely to represent efficient use of finite health care resources, although periodic testing (e.g., 1 or 2 times per week) may be cost-effective. Reduced test strip price would likely also improve cost-effectiveness.Self-monitoring of blood glucose in patients with diabetes who use insulin may contribute to improved glycemic control and reduced hypoglycemia by allowing for self-adjustments in insulin dose to be made based on meter readings.¹ Self-monitoring may also allow for appropriate changes in diet and physical activity to be made. However, the benefits of self-monitoring of blood glucose for patients not using insulin are less clear. Hypoglycemia is less frequent in this population² and is confined mainly to those taking secretagogues. The degree to which patients can adjust the dose of oral antidiabetes drugs in response to readings is limited.Nevertheless, self-monitoring of blood glucose is routinely recommended for patients who are not using insulin.¹ This results in major investments in this technology by patients and payers.³ In 2006, $250 million was spent on blood glucose test strips in 8 publicly funded drugs plans in Newfoundland and Labrador, Nova Scotia, Quebec, Ontario, Manitoba, Saskatchewan and British Columbia, while over $120 million was spent in privately funded drug plans in Canada.⁴ In some publicly funded drug plans in Canada, blood glucose test strips are among the top 5 classes in terms of total expenditure,⁵ with costs exceeding those for all oral antidiabetes drugs combined.^4,6 It is estimated that more than 50% of the total expenditure on blood glucose test strips is for patients with type 2 diabetes who are not using insulin.³ Costs related to test strips are expected to rise steadily^5,7 because of the increasing prevalence of type 2 diabetes.⁸Decisions about the prescribing and reimbursement of blood glucose test strips require consideration of information about the costs and clinical benefits.^9,10 As part of a larger initiative to determine the optimal use of this technology, we sought to determine the cost-effectiveness of self-monitoring of blood glucose for patients with type 2 diabetes who do not use insulin, based on data from our systematic review¹¹ of the available clinical evidence.     

Empagliflozin on top of metformin treatment improves arterial function in patients with type 1 diabetes mellitus

Background

Deteriorated arterial function and high incidence of cardiovascular events characterise diabetes mellitus. Metformin and recent antidiabetic drugs, SGLT2 inhibitors, reduce cardiovascular events. We explored the possible effects of empagliflozin’s effect on top of metformin treatment on endothelial function and arterial stiffness parameters in type 1 diabetes mellitus (T1DM) patients.

Methods

Forty T1DM patients were randomised into three treatment groups: (1) empagliflozin (25 mg daily), (2) metformin (2000 mg daily) and (3) empagliflozin/metformin (25 mg daily and 2000 mg daily, respectively). The fourth group received placebo. Arterial function was assessed at inclusion and after 12 weeks treatment by: endothelial function [brachial artery flow-mediated dilation (FMD), reactive hyperaemia index (RHI)], arterial stiffness [pulse wave velocity (PWV) and common carotid artery stiffness (β-stiffness)]. For statistical analysis one-way analysis of variance with Bonferroni post-test was used.

Results

Empagliflozin on top of metformin treatment significantly improved endothelial function as did metformin after 12 weeks of treatment: FMD [2.6-fold (P?<?0.001) vs. 1.8-fold (P?<?0.05)] and RHI [1.4-fold (P?<?0.01) vs. 1.3-fold (P?<?0.05)]. Empagliflozin on top of metformin treatment was superior to metformin in improving arterial stiffness parameters; it significantly improved PWV and β-stiffness compared to metformin [by 15.8% (P?<?0.01) and by 36.6% (P?<?0.05), respectively]. Metformin alone did not influence arterial stiffness.

Conclusion

Empagliflozin on top of metformin treatment significantly improved arterial stiffness compared to metformin in T1DM patients. Endothelial function was similarly improved in all treatment groups. Empagliflozin seems to possess a specific capacity to decrease arterial stiffness, which could support its cardioprotective effects observed in large clinical studies.Trial registration Clinical trial registration: NCT03639545

     

利拉鲁肽联合二甲双胍对2型糖尿病合并肥胖患者胰岛β细胞功能以及内脏脂肪水平的影响

目的分析利拉鲁肽联合二甲双胍对2型糖尿病（T2DM）合并肥胖患者胰岛β细胞功能以及内脏脂肪水平的影响。 方法选取重庆两江新区第一人民医院2016年3月至2018年3月收治的194例T2DM合并肥胖患者,将其随机分为研究组、对照组,各97例,均给予为期16周的二甲双胍治疗,研究组加用利拉鲁肽皮下注射。比较两组患者治疗前后血糖、胰岛β细胞功能指数（HOMA-β）、内脏脂肪水平（VFL）等指标变化,总结利拉鲁肽在T2DM合并肥胖治疗中的临床价值。计数资料采用卡方检验,计量资料采用t检验。 结果研究组不良反应发生率为29.90﹪,对照组为23.71﹪,组间比较差异无统计学意义（χ²= 0.946,P > 0.05）。两组患者治疗后FPG、2 hPG、BMI均较治疗前下降,研究组治疗后FPG、2 hPG、BMI分别为（7.12±1.35）?mmol/?L、（9.03±2.66）?mmol/L、（26.32±1.60）kg/m²,均低于对照组的（7.83± 1.19）?mmol/L、（10.57±2.39）?mmol/?L、（27.74±1.66）kg/m²,差异有统计学意义（t = 3.886、4.241、6.066,P均?< 0.05）。两组患者治疗后HOMA-β较治疗前升高,HOMA-IR较治疗前下降,研究组治疗后HOMA-β为155.69±24.55,高于对照组的117.49±21.98,其HOMA-IR为2.30±0.71,低于后者的3.20±0.64,差异有统计学意义（t = 11.407、9.273,P均< 0.05）。两组患者治疗后VFL、脂肪率均较治疗前下降,研究组治疗后VFL、脂肪率低于对照组,且其治疗后肌肉含量较治疗前下降,差异有统计学意义（P < 0.05）。 结论在二甲双胍的基础上联合利拉鲁肽能够通过改善胰岛β细胞功能、减少内脏脂肪,达到改善T2DM合并肥胖患者的胰岛素抵抗的目的,是一种安全、有效的治疗方案。     

Anti-GAD-positive patients with type 1 diabetes mellitus have higher prevalence of autoimmune thyroiditis than anti-GAD-negative patients with type 1 and type 2 diabetes mellitus

The aim of our study was to evaluate antibodies against thyroglobulin (anti-TG) and thyroid peroxidase (anti-TPO) - markers of autoimmune thyroiditis - in several groups of adult patients with type 1 and type 2 diabetes mellitus (DM). We were particularly interested whether the presence of thyroid antibodies is related to the positivity of glutamic acid decarboxylase antibodies (anti-GAD). We found elevated anti-GAD in 46 % (97/210) patients with type 1 DM. All patients with type 2 diabetes were anti-GAD-negative. At least one thyroid antibody (anti-TG and/or anti-TPO) was found in 30 % (62/210) patients with type 1 DM and 27 % (22/83) type 2 diabetes patients. The patients with type 1 DM were further grouped according to their anti-GAD status. The anti-GAD-positive patients had a higher prevalence of anti-TG antibodies than the anti-GAD-negative patients (25 % vs. 12 %, p=0.03) as well as anti-TPO antibodies (32 % vs. 12 %, p<0.001). At least one thyroid antibody was detected in 39 % (38/97) of anti-GAD-positive but only in 21 % (24/113) of anti-GAD-negative patients with type 1 DM (p=0.006). No significant difference in the frequency of thyroid antibodies was found between anti-GAD-negative patients with type 1 and type 2 DM (21 % vs. 27 %, p=0.4). The groups with or without thyroid antibodies in both type 1 and type 2 diabetic patients did not differ in actual age, the age at diabetes onset, duration of diabetes, body mass index or HbA1c level. Patients with elevated thyroid antibodies had significantly higher levels of TSH than those without thyroid antibodies (1.86 vs. 3.22 mIU/l, p=0.04 in type 1 DM; 2.06 vs. 4.89 mIU/l, p=0.003 in type 2 DM). We conclude that there is a higher frequency of thyroid-specific antibodies in anti-GAD-positive adult patients with type 1 DM than in anti-GAD-negative patients or in patients with type 2 DM. Patients with or without thyroid antibodies do not differ in age, DM onset and duration, BMI or HbA1c. Thyroid antibodies-positive patients have higher levels of thyroid stimulating hormone (TSH).     

线粒体基因组D-Loop区基因多态性与2型糖尿病的相关性

随机选取199例浙江地区2型糖尿病患者与102例正常对照, 采用聚合酶链反应(Polymerase chain re-action, PCR)、基因片段直接测序来检测线粒体基因组D-Loop区域基因变异情况, 同时分析其与主要临床指标的关系。结果显示: 线粒体基因组D-Loop区域为一高变异区, np73A-G、np263A-G、np16223C-T、np16519T-C为4个高变异位点; 发现29个未见报道的新变异位点; np193A-G、np234A-G、np16108C-T等变异与糖尿病家族史有关。这表明浙江籍汉族人线粒体基因组D-Loop区存在大量基因多态性现象, 此区域的某些变异可能与糖尿病的发生发展等具有一定相关性。     

Gluconeogenesis in moderately and severely hyperglycemic patients with type 2 diabetes mellitus

We tested the generally accepted concept that increased gluconeogenesis (GNG) and endogenous glucose production (EGP) are the main reasons for postabsorptive hyperglycemia in patients with type 2 diabetes mellitus (T2DM). GNG was measured with the (2)H(2)O method by use of both the C5-to-C2 ratio (C5/C2, with gas chromatography-mass spectrometry) and the C5-to-(2)H(2)O ratio (C5/(2)H(2)O, with isotope ratio mass spectrometry), and EGP was measured with 3-[(3)H]glucose in 27 patients with T2DM [13 with fasting plasma glucose (FPG) >10 mM and 14 with FPG <10 mM] and in 7 weight- and age-matched nondiabetic controls. The results showed 1) that GNG could be determined accurately with (2)H(2)O by using either C5/C2 or C5/(2)H(2)O; 2) that whereas after an overnight fast of 16 h, GNG was higher in the entire group of patients with T2DM than in controls (6.4 vs. 5.0 micromol. kg(-1). min(-1) or 60.4 vs. 51.4% of EGP, P < 0.02), GNG was within normal limits (less than the mean +/- 2 SD of controls or <65.3%) in 11/14 (79%) patients with mild to moderate hyperglycemia (FPG <10 mM) and in 5/13 (38%) of patients with severe hyperglycemia (FPG 10-20 mM); 3) that elevated GNG in T2DM was associated with a 43% decrease in prehepatic insulin secretion, i.e., with hepatic insulin deficiency; and 4) that FPG correlated significantly with glucose clearance (insulin resistance) (r = 0.70) and with GNG (r = 0.50) or EGP (r = 0.45). We conclude 1) that peripheral insulin resistance is at least as important as GNG (and EGP) as a cause of postabsorptive hyperglycemia in T2DM and 2) that GNG and EGP in T2DM are increased under conditions of significant hepatic insulin deficiency and thus probably represent a late event in the course of T2DM.     

Randomised controlled trial of structured personal care of type 2 diabetes mellitus

ObjectiveTo assess the effect of a multifaceted intervention directed at general practitioners on six year mortality, morbidity, and risk factors of patients with newly diagnosed type 2 diabetes.DesignPragmatic, open, controlled trial with randomisation of practices to structured personal care or routine care; analysis after 6 years.Setting311 Danish practices with 474 general practitioners (243 in intervention group and 231 in comparison group).Participants874 (90.1%) of 970 patients aged ⩾40 years who had diabetes diagnosed in 1989-91 and survived until six year follow up.InterventionRegular follow up and individualised goal setting supported by prompting of doctors, clinical guidelines, feedback, and continuing medical education.ResultsPredefined non-fatal outcomes and mortality were the same in both groups. The following risk factor levels were lower for intervention patients than for comparison patients (median values): fasting plasma glucose concentration (7.9 v 8.7 mmol/l, P=0.0007), glycated haemoglobin (8.5% v 9.0%, P<0.0001; reference range 5.4-7.4%), systolic blood pressure (145 v 150 mm Hg, P=0.0004), and cholesterol concentration (6.0 v 6.1 mmol/l, P=0.029, adjusted for baseline concentration). Both groups had lost weight since diagnosis (2.6 v 2.0 kg). Metformin was the only drug used more frequently in the intervention group (24% (110/459) v 15% (61/415)).Intervention doctors arranged more follow up consultations, referred fewer patients to diabetes clinics, and set more optimistic goals.ConclusionsIn primary care, individualised goals with educational and surveillance support may for at least six years bring risk factors of patients with type 2 diabetes to a level that has been shown to reduce diabetic complications but without weight gain.

What is already known on this topic

Evidence is increasing that control of hyperglycaemia, hypertension, and dyslipidaemia may postpone the development of diabetic complications in patients with type 2 diabetesMaintaining good control over a long period can be difficult

What this study adds

Structured individualised personal care with educational and surveillance support for general practitioners reduced levels of risk factors in type 2 diabetic patients after six yearsRisk factors were reduced to a level that has been shown to have a beneficial effect on diabetic complicationsParticipants also showed modest weight loss     

1533例2型糖尿病患者合并症与并发症的调查分析

目的:了解上海地区门诊糖尿病患者的各种慢性合并症与并发症及其相关危险因素.方法:调查我院门诊糖尿病患者1533例,记录慢性合并症、并发症及各种相关危险因素并进行相关的统计分析.结果:上海地区糖尿病患者的各种慢性合并症与并发症的发生率由高到低依次为周围血管病变67.0%,高血压63.2%,血脂紊乱45.1%,家族糖尿病34.8%,高尿酸血症29.O%,视网膜病变28.0%,脂肪肝27.1%,糖尿病肾病21.1%.女性患者高尿酸血症、脂肪肝、家族糖尿病史发生率高于男性,各种慢性合并症与并发症多随年龄与病程的增加而升高.结论:上海地区门诊糖尿病患者各种慢性合并症与并发症的发病率较高,定期监测并联合控制血糖、血压、血脂水平是防治各种慢性合并症与并发症的关键.     

Effectiveness and safety of exenatide in Korean patients with type 2 diabetes inadequately controlled with oral hypoglycemic agents: an observational study in a real clinical practice

Background

Randomized clinical trials have shown the efficacy and safety of short-acting exenatide in patients with type 2 diabetes mellitus (T2DM). The aim of this observational study was to investigate the effectiveness and safety of exenatide twice a day in Korean patients with T2DM who are suboptimally controlled with oral hypoglycemic agents.

Methods

This study was a post hoc analysis of multi-center (71 centers), prospective, observational, single-arm, post-marketing study of short-acting exenatide 5 to 10 μg twice a day from March 2008 to March 2014 and analyzed those who finished the follow-up over 20 weeks of medication. Changes of hemoglobin A1c (HbA1c), fasting plasma glucose (FPG), and body weight values before and after exenatide treatment were analyzed. Adverse events and adverse drug reactions were estimated in patients who were treated with exenatide at least once and for whom follow-up for safety has been completed.

Results

After 20 weeks treatment with exenatide, mean HbA1c and body weight were significantly reduced from 8.4% to 7.7% and from 83.4 kg to 80.2 kg, respectively (both p < 0.001). Subjects with higher baseline glucose and HbA1c levels showed an independent association with a greater reduction in glucose level. In addition, short duration of diabetes less than 5 years was an independent predictor for the improvement in glucose level. The majority of study subjects showed a reduction in both body weight and glucose level (63.3%) after exenatide treatment. In terms of safety profile, exenatide treatment was generally well-tolerated and the incidence of severe adverse event was rare (0.8%). The gastrointestinal side effects were most common and hypoglycemia was reported in 1.7% of subjects.

Conclusion

In real clinical practice, 20 weeks treatment with short-acting exenatide was well tolerated and showed a significant body weight and glucose reduction in Korean patients with T2D who are suboptimally controlled with oral hypoglycemic agents.

Trial registration

ClinicalTirals.gov, number NCT02090673, registered 14 February 2008.