Nateglinide and glibenclamide metabolic effects in naïve type 2 diabetic patients treated with metformin

The current status of low-density lipoprotein cholesterol for primary prevention of coronary artery disease in late-stage elderly persons with type 2 diabetes mellitus: A retrospective, single-center study

Aims/Introduction

The importance of low‐density lipoprotein cholesterol (LDL‐C) in the primary prevention of cardiovascular disease has recently been reported in the population aged ≥75 years with hypercholesterolemia. Therefore, the current status of LDL‐C management for primary prevention of coronary artery disease in patients aged ≥75 years with type 2 diabetes mellitus was investigated.

Materials and Methods

A total of 124 patients aged ≥75 years who had type 2 diabetes mellitus, but no coronary artery disease, were investigated. The patients' background characteristics, LDL‐C, glycemic status, ankle‐brachial index and cardio‐ankle vascular index were compared between patients taking and not taking LDL‐C‐lowering agents, such as hydroxymethylglutaryl‐CoA reductase inhibitors (statins) and ezetimibe. The details of the antihyperlipidemic and antidiabetic agents used in the present study were also examined.

Results

LDL‐C was significantly lower in patients taking LDL‐C‐lowering agents (LDLCLT[+]) than in patients not taking them (LDLCLT[−]), although LDL‐C was maintained <120 mg/dL in both groups (93.0 mg/dL vs 102.1 mg/dL). Approximately half of the cases in the LDLCLT(+) group received moderate‐intensity statins, with pitavastatin being the most prescribed statin. Glycated hemoglobin was significantly lower in the LDLCLT(+) group than in the LDLCLT(−) group (6.9% vs 7.3%). Sodium‐glucose transporter 2 inhibitors were more frequently used in the LDLCLT(+) group than in the LDLCLT(−) group. The ankle‐brachial index/cardio‐ankle vascular index did not differ between the groups.

Conclusion

Low‐density lipoprotein cholesterol was properly managed for primary prevention of coronary artery disease in patients aged ≥75 years with type 2 diabetes mellitus regardless of the presence or absence of LDL‐C‐lowering agents.

Metformin and second- or third-generation sulphonylurea combination therapy for adults with type 2 diabetes mellitus

BACKGROUND

The number of people with type 2 diabetes mellitus (T2DM) is increasing worldwide. The combination of metformin and sulphonylurea (M+S) is a widely used treatment. Whether M+S shows better or worse effects in comparison with other antidiabetic medications for people with T2DM is still controversial.

OBJECTIVES

To assess the effects of metformin and sulphonylurea (second- or third-generation) combination therapy for adults with type 2 diabetes mellitus.

SEARCH METHODS

We updated the search of a recent systematic review from the Agency for Healthcare Research and Quality (AHRQ). The updated search included CENTRAL, MEDLINE, Embase, ClinicalTrials.gov and WHO ICTRP. The date of the last search was March 2018. We searched manufacturers' websites and reference lists of included trials, systematic reviews, meta-analyses and health technology assessment reports. We asked investigators of the included trials for information about additional trials.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) randomising participants 18 years old or more with T2DM to M+S compared with metformin plus another glucose-lowering intervention or metformin monotherapy with a treatment duration of 52 weeks or more.

DATA COLLECTION AND ANALYSIS

Two review authors read all abstracts and full-text articles and records, assessed risk of bias and extracted outcome data independently. We used a random-effects model to perform meta-analysis, and calculated risk ratios (RRs) for dichotomous outcomes and mean differences (MDs) for continuous outcomes, using 95% confidence intervals (CIs) for effect estimates. We assessed the certainty of the evidence using the GRADE instrument.

MAIN RESULTS

We included 32 RCTs randomising 28,746 people. Treatment duration ranged between one to four years. We judged none of these trials as low risk of bias for all 'Risk of bias' domains. Most important events per person were all-cause and cardiovascular mortality, serious adverse events (SAE), non-fatal stroke (NFS), non-fatal myocardial infarction (MI) and microvascular complications. Most important comparisons were as follows:Five trials compared M+S (N = 1194) with metformin plus a glucagon-like peptide 1 analogue (N = 1675): all-cause mortality was 11/1057 (1%) versus 11/1537 (0.7%), risk ratio (RR) 1.15 (95% confidence interval (CI) 0.49 to 2.67); 3 trials; 2594 participants; low-certainty evidence; cardiovascular mortality 1/307 (0.3%) versus 1/302 (0.3%), low-certainty evidence; serious adverse events (SAE) 128/1057 (12.1%) versus 194/1537 (12.6%), RR 0.90 (95% CI 0.73 to 1.11); 3 trials; 2594 participants; very low-certainty evidence; non-fatal myocardial infarction (MI) 2/549 (0.4%) versus 6/1026 (0.6%), RR 0.57 (95% CI 0.12 to 2.82); 2 trials; 1575 participants; very low-certainty evidence.Nine trials compared M+S (N = 5414) with metformin plus a dipeptidyl-peptidase 4 inhibitor (N = 6346): all-cause mortality was 33/5387 (0.6%) versus 26/6307 (0.4%), RR 1.32 (95% CI 0.76 to 2.28); 9 trials; 11,694 participants; low-certainty evidence; cardiovascular mortality 11/2989 (0.4%) versus 9/3885 (0.2%), RR 1.54 (95% CI 0.63 to 3.79); 6 trials; 6874 participants; low-certainty evidence; SAE 735/5387 (13.6%) versus 779/6307 (12.4%), RR 1.07 (95% CI 0.97 to 1.18); 9 trials; 11,694 participants; very low-certainty evidence; NFS 14/2098 (0.7%) versus 8/2995 (0.3%), RR 2.21 (95% CI 0.74 to 6.58); 4 trials; 5093 participants; very low-certainty evidence; non-fatal MI 15/2989 (0.5%) versus 13/3885 (0.3%), RR 1.45 (95% CI 0.69 to 3.07); 6 trials; 6874 participants; very low-certainty evidence; one trial in 64 participants reported no microvascular complications were observed (very low-certainty evidence).Eleven trials compared M+S (N = 3626) with metformin plus a thiazolidinedione (N = 3685): all-cause mortality was 123/3300 (3.7%) versus 114/3354 (3.4%), RR 1.09 (95% CI 0.85 to 1.40); 6 trials; 6654 participants; low-certainty evidence; cardiovascular mortality 37/2946 (1.3%) versus 41/2994 (1.4%), RR 0.78 (95% CI 0.36 to 1.67); 4 trials; 5940 participants; low-certainty evidence; SAE 666/3300 (20.2%) versus 671/3354 (20%), RR 1.01 (95% CI 0.93 to 1.11); 6 trials; 6654 participants; very low-certainty evidence; NFS 20/1540 (1.3%) versus 16/1583 (1%), RR 1.29 (95% CI 0.67 to 2.47); P = 0.45; 2 trials; 3123 participants; very low-certainty evidence; non-fatal MI 25/1841 (1.4%) versus 21/1877 (1.1%), RR 1.21 (95% CI 0.68 to 2.14); P = 0.51; 3 trials; 3718 participants; very low-certainty evidence; three trials (3123 participants) reported no microvascular complications (very low-certainty evidence).Three trials compared M+S (N = 462) with metformin plus a glinide (N = 476): one person died in each intervention group (3 trials; 874 participants; low-certainty evidence); no cardiovascular mortality (2 trials; 446 participants; low-certainty evidence); SAE 34/424 (8%) versus 27/450 (6%), RR 1.68 (95% CI 0.54 to 5.21); P = 0.37; 3 trials; 874 participants; low-certainty evidence; no NFS (1 trial; 233 participants; very low-certainty evidence); non-fatal MI 2/215 (0.9%) participants in the M+S group; 2 trials; 446 participants; low-certainty evidence; no microvascular complications (1 trial; 233 participants; low-certainty evidence).Four trials compared M+S (N = 2109) with metformin plus a sodium-glucose co-transporter 2 inhibitor (N = 3032): all-cause mortality was 13/2107 (0.6%) versus 19/3027 (0.6%), RR 0.96 (95% CI 0.44 to 2.09); 4 trials; 5134 participants; very low-certainty evidence; cardiovascular mortality 4/1327 (0.3%) versus 6/2262 (0.3%), RR 1.22 (95% CI 0.33 to 4.41); 3 trials; 3589 participants; very low-certainty evidence; SAE 315/2107 (15.5%) versus 375/3027 (12.4%), RR 1.02 (95% CI 0.76 to 1.37); 4 trials; 5134 participants; very low-certainty evidence; NFS 3/919 (0.3%) versus 7/1856 (0.4%), RR 0.87 (95% CI 0.22 to 3.34); 2 trials; 2775 participants; very low-certainty evidence; non-fatal MI 7/890 (0.8%) versus 8/1374 (0.6%), RR 1.43 (95% CI 0.49 to 4.18; 2 trials); 2264 participants; very low-certainty evidence; amputation of lower extremity 1/437 (0.2%) versus 1/888 (0.1%); very low-certainty evidence.Trials reported more hypoglycaemic episodes with M+S combination compared to all other metformin-antidiabetic agent combinations. Results for M+S versus metformin monotherapy were inconclusive. There were no RCTs comparing M+S with metformin plus insulin. We identified nine ongoing trials and two trials are awaiting assessment. Together these trials will include approximately 16,631 participants.

AUTHORS' CONCLUSIONS

There is inconclusive evidence whether M+S combination therapy compared with metformin plus another glucose-lowering intervention results in benefit or harm for most patient-important outcomes (mortality, SAEs, macrovascular and microvascular complications) with the exception of hypoglycaemia (more harm for M+S combination). No RCT reported on health-related quality of life.

Effects of sulfonylureas on lipids in type 2 diabetes mellitus: a meta-analysis of randomized controlled trials

OBJECTIVE

Previous studies suggested that dyslipidemia was potentially associated with anti-diabetic medications of sulfonylureas (SUs). The results were, however, inconsistent. Therefore, we conducted a meta-analysis of randomized controlled trials (RCTs) to assess the effects of SUs on the level of lipids in patients with type 2 diabetes mellitus (T2DM).

METHODS

We searched PubMed, EMBASE, and CENTRAL databases for RCTs that addressed the effects of second- and/or third-generation SUs used in T2DM patients on lipids profiles with study duration of at least 12 weeks. Two reviewers independently screened literature, collected data, and assessed methodological quality of included studies. The meta-analysis was performed by using the RevMan5.1 software.

RESULTS

A total of 59 RCTs were included, of which 52 were included for final meta-analysis. The results suggested that SUs statistically increased the levels of FFA (SMD = 0.24, 95%CI 0.06 to 0.42) and TG (MD = 0.06, 95%CI 0.02 to 0.10), but decreased HDL-C (MD = -0.07, 95%CI -0.11 to -0.04) and LDL-C (MD = -0.11, 95%CI -0.17 to -0.04); but the SUs had no effect on TC (MD = 0.01, 95%CI -0.05 to 0.08), ApoA1 (MD = 0.01, 95%CI -0.03 to 0.04), and Apo B (MD = -0.01, 95%CI -0.05 to 0.03). When compared to metformin, SUs could increase TC and LDL-C; compared to glinides, SUs increased TC and lowered HDL-C; compared to thiazolidinediones, SUs reduced TC, LDL-C, HDL-C, and increase TG.

CONCLUSIONS

SUs have a small effect on lipids, although they may statistically increase the level of FFA and TG, and decrease LDL-C and HDL-C.

The effect of a dual combination of noninsulin antidiabetic drugs on lipids: a systematic review and network meta-analysis

OBJECTIVE

As an ever widening array of anti-hyperglycemic agents are now available, the effect of these drugs on lipids is increasingly complex and controversial. The present meta-analysis was designed to clarify the effect of a dual combination of noninsulin anti-hyperglycemic agents on lipids in type 2 diabetes.

METHODS

Randomized controlled trials comparing different dual combinations of antidiabetic drugs were identified by searching PubMed, Cochrane Library, and Embase. Study selection, data abstraction and quality assessment were carried out by two reviewers independently. Change in low-density lipoprotein (LDL), high-density lipoprotein (HDL), triglyceride and total cholesterol were pooled by both traditional meta-analysis and network meta-analysis.

RESULTS

Eighteen studies with a total of 10,222 patients were included. Network meta-analysis suggested that metformin + dipeptidyl peptidase-4 inhibitors (DPP-4) (LDL cholesterol: -0.19 mmol/L; HDL cholesterol: 0.06 mmol/L; triglycerides: -0.73 mmol/L; total cholesterol: -0.4 mmol/L) and metformin + glucagon-like peptide-1 (GLP-1) agonist (LDL cholesterol: -0.3 mmol/L; HDL cholesterol: 0.06 mmol/L; triglycerides: -0.64 mmol/L; total cholesterol: -0.5 mmol/L) were associated with relatively larger beneficial effects on the lipid profile among all combinations. Compared with metformin + thiazolidinedione, metformin + GLP-1 agonist (mean difference: -0.38; 95% confidence interval [CI]: -0.66 to -0.10) significantly decreased LDL cholesterol. Metformin + thiazolidinedione showed a larger increase than metformin + sulfonylurea in HDL cholesterol (mean difference: 0.1; 95% CI: 0.01 to 0.21).

CONCLUSIONS

The effect of a dual combination of noninsulin anti-hyperglycemic agents on lipids is moderate to small, with metformin + DPP-4 inhibitor and metformin + GLP-1 agonist showing consistent beneficial effects on LDL cholesterol, HDL cholesterol, triglycerides and total cholesterol. Future trials are needed to confirm these findings.

The role of nateglinide and repaglinide, derivatives of meglitinide, in the treatment of type 2 diabetes mellitus

Type 2 diabetes mellitus (T2DM) is one of the most common chronic diseases worldwide, presenting a great challenge to the public health systems due to high morbidity and mortality, because of frequent micro-/macro-vascular complications. Many treatment options are now available, with different efficacy as well as mechanisms of action to improve deranged glucose metabolism. We review some of the available data on derivatives of meglitinide, namely nateglinide and repaglinide. These two compounds increase insulin secretion by a mechanism similar to the one of sulfonylureas, but with a shorter half-life. Nateglinide and repaglinide, derivatives of meglitinides, have characteristic pharmacodynamic and pharmacokinetic properties that, together with their proposed mechanism of action, make them useful for type 2 diabetes mellitus, especially when used in combination therapy.

Cardiovascular implications of antihyperglycemic therapies for type 2 diabetes

BACKGROUND

Several risk factors for cardiovascular disease (CVD), including insulin resistance/hyperinsulinemia, hyperglycemia, overweight/obesity, dyslipidemia, and hypertension, are often present in varying combinations in patients with type 2 diabetes mellitus (DM). Patients with a clustering of these risk factors, termed the metabolic syndrome, are at greater risk for CVD than are patients with only a single risk factor. Although glycemic control is the central feature of type 2 DM management, patients require an individualized approach to therapy that takes their other CVD risk factors into account.

OBJECTIVE

This review examined the effects of antidiabetes therapy on glycemic control, as well as its potential to affect body weight, serum lipids, and blood pressure (BP), and thus CVD risk.

METHODS

Information was obtained by searching the MEDLINE and EMBASE databases from 1995 through March 2010. The search terms included type 2 DM, metabolic syndrome, CV complications of type 2 DM, and therapy for type 2 DM. Articles that described relevant details of the metabolic syndrome, CV complications of type 2 DM, and effects of antidiabetes therapy on glycosylated hemoglobin, body weight, serum lipids, and BP were selected for in-depth review. Only English language publications were reviewed. Clinical trials, meta-analyses, and review articles on the key words were preferentially selected for review and analysis. Non-English language publications, case reports, letters to the editor, and similar types of publications were excluded.

RESULTS

Although all approved antidiabetes agents lowered glucose, their effect on other CV risk factors, such as BP, lipids, and weight, differed significantly. Therapy with insulin, the sulfonylureas, and the thiazolidinediones was associated with weight gain. Metformin and the dipeptidyl-peptidase-4 inhibitors were generally considered weight neutral, whereas the glucagon-like peptide-1 receptor agonists and amylin agonists were associated with weight loss. Metformin, sulfonylureas, thiazolidinedioness, and dipeptidyl-peptidase-4 inhibitors had modest effects on serum lipid levels and BP. The glucagon-like peptide-1 receptor agonists generally had beneficial effects on serum lipid levels and systolic and diastolic BP.

CONCLUSION

A wide variety of agents were available to aid glycemic control in patients with type 2 DM. These agents had variable effects on known CV risk factors that might be present in this patient population, including excess body weight, elevated BP, and increased serum lipids. Some of the newer agents improved glycemic control while also having potentially favorable effects on these CV risk factors. The impact of various agents on known CV risk factors should be considered when selecting a therapeutic regimen.

Therapies for type 2 diabetes: lowering HbA1c and associated cardiovascular risk factors

OBJECTIVES

To summarize data supporting the effects of antidiabetes agents on glucose control and cardiovascular risk factors in patients with type 2 diabetes.

METHODS

Studies reporting on the effects of antidiabetes agents on glycemic control, body weight, lipid levels, and blood pressure parameters are reviewed and summarized for the purpose of selecting optimal therapeutic regimens for patients with type 2 diabetes.

RESULTS

National guidelines recommend the aggressive management of cardiovascular risk factors in patients with type 2 diabetes, including weight loss and achieving lipid and blood pressure treatment goals. All antidiabetes pharmacotherapies lower glucose; however, effects on cardiovascular risk factors vary greatly among agents. While thiazolidinediones, sulfonylureas, and insulin are associated with weight gain, dipeptidyl peptidase-4 inhibitors are considered weight neutral and metformin can be weight neutral or associated with a small weight loss. Glucagon-like peptide-1 receptor agonists and amylinomimetics (e.g. pramlintide) result in weight loss. Additionally, metformin, thiazolidinediones, insulin, and glucagon-like peptide-1 receptor agonists have demonstrated beneficial effects on lipid and blood pressure parameters.

CONCLUSION

Management of the cardiovascular risk factors experienced by patients with type 2 diabetes requires a multidisciplinary approach with implementation of treatment strategies to achieve not only glycemic goals but to improve and/or correct the underlying cardiovascular risk factors.

Comparing the actions of older and newer therapies on body weight: to what extent should these effects guide the selection of antidiabetic therapy?

BACKGROUND

Type 2 diabetes patients are usually overweight or obese. Further weight gain induced by antidiabetic treatment should be avoided if possible. Much attention has been focussed recently on the potential for GLP-1 mimetics, in particular, to reduce weight.

AIMS

Effects on weight are but one of several important criteria in selecting antidiabetic therapy, however. This review explores the effects on weight of older classes of antidiabetic agents (metformin, sulfonylureas, thiazolidinediones) and the newer drugs acting via the GLP-1 system. Other aspects of their therapeutic profiles and current therapeutic use are reviewed briefly to place effects on weight within a broader context.

FINDINGS

Comparative trials demonstrated weight neutrality or weight reduction with metformin, and weight increases with a sulfonylurea or thiazolidinedione. There was no clinically significant change in weight with DPP-4 inhibitors and a small and variable decrease in weight (about 3 kg or less) with GLP-1 mimetics. Improved clinical outcomes have been demonstrated for metformin and a sulfonylurea (cardiovascular and microvascular benefits, respectively, in the UK Prospective Diabetes Study), and secondary endpoints improved modestly with pioglitazone in the PROactive trial. No outcome benefits have been demonstrated to date with GLP-1-based therapies, and these agents exert little effect on cardiovascular risk factors. Concerns remain over long-term safety of these agents and this must be weighed against any potential benefit on weight management.

CONCLUSIONS

Considering effects on weight within the overall risk-benefit profile of antidiabetic therapies, metformin continues to justify its place at the head of current management algorithms for type 2 diabetes, due to its decades-long clinical evidence base, cardiovascular outcome benefits and low cost.

Combination of nateglinide with thiazolidinediones in Type 2 diabetes

Insulin sensitivity and insulin secretion are reciprocally related such that insulin resistance is adapted by increased insulin secretion to maintain normal glucose and lipid homeostasis. Treatment of Type 2 diabetes should aim to restore and sustain the normal relationship between insulin sensitivity and secretion. Nateglinide is a rapid-onset, short-acting insulin-secretion enhancer that restores early-phase insulin secretion, reduces postprandial glucose excursions and prevents long-term hyperinsulinemia. Given its mechanism of action, it is evident that nateglinide would be more effective when used in combination with an insulin sensitizer, such as the thiazolidinediones. Thiazolidinediones do not stimulate insulin release and, therefore, are potentially suitable candidates for combination therapy with an insulin-secretion enhancer, such as nateglinide. Combination therapy of thiazolidinediones with nateglinide is effective, carries low risk of hypoglycemia and is suitable for patients with moderate renal impairment, although weight gain and edema are common side effects. Further studies are needed to determine whether nateglinide in combination with thiazolidinediones will help clinicians better achieve their treatment goals in targeting Type 2 diabetes. Moreover, comparative studies between nateglinide and medications targeting postprandial glycemia, such as dipeptidyl peptidase-4 inhibitors and glucagon-like peptide-1 analogues, are necessary. This article summarizes data concerning the mechanism of action, efficacy and safety of therapy with nateglinide and thiazolidinediones as monotherapy and in combination treatment, and aims at a better understanding of the substrate defects their synergy hopes to defy.