Effect of normalization of fasting glucose by intensified insulin therapy and influence of eNOS polymorphisms on the incidence of restenosis after peripheral angioplasty in patients with type 2 diabetes: a randomized, open-label clinical trial

Systematic review and meta-analysis of the genetics of peripheral arterial disease

Background

Peripheral artery disease (PAD) impacts more than 200 million people worldwide. The understanding of the genetics of the disease and its clinical implications continue to evolve. This systematic review provides a comprehensive summary of all DNA variants that have been studied in association with the diagnosis and progression of PAD, with a meta-analysis of the ones replicated in the literature.

Methods

A systematic review of all studies examining DNA variants associated with the diagnosis and progression of PAD was performed. Candidate gene and genome-wide association studies (GWAS) were included. A meta-analysis of 13 variants derived from earlier smaller candidate gene studies of the diagnosis of PAD was performed. The literature on the progression of PAD was limited, and a meta-analysis was not feasible because of the heterogeneity in the criteria used to characterize it.

Results

A total of 231 DNA variants in 112 papers were studied for the association with the diagnosis of PAD. There were significant variations in the definition of PAD and the selection of controls in the various studies. GWAS have established 19 variants associated with the diagnosis of PAD that were replicated in several large patient cohorts. Only variants in intercellular adhesion molecule-1 (rs5498), IL-6 (rs1800795), and hepatic lipase (rs2070895) showed significant association with the diagnosis of PAD. However, these variants were not noted in the published GWAS.

Conclusions

Genetic research in the diagnosis of PAD has significant heterogeneity, but recent GWAS have demonstrated variants consistently associated with the disease. More research focusing on the progression of PAD is needed to identify patients at risk of adverse events and develop strategies that would improve their outcomes.

The Impact of Modern Anti-Diabetic Treatment on Endothelial Progenitor Cells

Diabetes is one of the leading chronic diseases globally with a significant impact on mortality. This condition is associated with chronic microvascular and macrovascular complications caused by vascular damage. Recently, endothelial progenitor cells (EPCs) raised interest due to their regenerative properties. EPCs are mononuclear cells that are derived from different tissues. Circulating EPCs contribute to regenerating the vessel's intima and restoring vascular function. The ability of EPCs to repair vascular damage depends on their number and functionality. Diabetic patients have a decreased circulating EPC count and impaired EPC function. This may at least partially explain the increased risk of diabetic complications, including the increased cardiovascular risk in these patients. Recent studies have confirmed that many currently available drugs with proven cardiovascular benefits have beneficial effects on EPC count and function. Among these drugs are also medications used to treat different types of diabetes. This manuscript aims to critically review currently available evidence about the ways anti-diabetic treatment affects EPC biology and to provide a broader context considering cardiovascular complications. The therapies that will be discussed include lifestyle adjustments, metformin, sulphonylureas, gut glucosidase inhibitors, thiazolidinediones, dipeptidyl peptidase 4 inhibitors, glucagon-like peptide 1 receptor analogs, sodium-glucose transporter 2 inhibitors, and insulin.

Medical adjunctive therapy for patients with chronic limb-threatening ischemia: a systematic review

INTRODUCTION

The aim of this article is to systematically review the literature on medical adjunctive therapy for patients with chronic limb-threatening ischemia (CLTI).

EVIDENCE ACQUISITION

MEDLINE, Embase, and Cochrane Database of Systematic Reviews were searched for studies published between January 1st, 2009, and June 1st, 2019. Articles that studied medical treatment of CLTI patients and reported clinical outcomes were eligible. Main exclusion criteria were case reports <20 patients, incorrect publication type, and CLTI caused by Buerger disease. The primary end point was major amputation (above the ankle) in studies with a follow-up of ≥6 months. Secondary end points were other clinical end points such as death and wound healing. Study quality was assessed according to the Downs and Black checklist.

EVIDENCE SYNTHESIS

Included were 42 articles: four focused on antiplatelet therapy, five on antihypertensive medication, 6 on lipid-lowering therapy, 16 on stem cell therapy, three on growth factors, five on prostanoids, and one study each on cilostazol, glucose-lowering therapy, spinal cord stimulation, sulodexide, and hemodilution. Calcium channel blockers, iloprost, cilostazol, and hemodilution showed significant improvement of limb salvage, but data are limited. Stem cell therapy showed no significant improvement of limb salvage but could potentially improve wound healing. Antiplatelets, antihypertensives, and statins showed significantly lower cardiovascular events rates but not evident lower major amputation rates. The quality of the studies was fair to good.

CONCLUSIONS

Certain medical therapies serve to improve limb salvage next to revascularization in CLTI patients, whereas others are important in secondary prevention. Because high quality evidence is limited, further research is needed.

Improved angiogenic activity of endothelial progenitor cell in diabetic patients treated with insulin plus metformin

Type 2 diabetes (T2DM) is associated with an increased vascular disease. Moreover, endothelial progenitor cell (EPC) function is impaired in diabetic patients. Decreased EPC number plays a critical role in reduced endothelial repair and development of the vascular disorder. To determine the effect of metformin and insulin plus metformin on functional activity of EPCs, 130 participants were divided into three groups (group 1: healthy control; group 2: metformin; group 3: insulin plus metformin). The concentration of EPCs in the circulation was first quantified. Thereafter, circulating EPCs (cEPCs) were harvested and the biological features of these cells including proliferative, clonogenicity, tubulogenic, and migratory properties were analyzed after expansion. The serum protein levels of some proangiogenic factors were also measured. Our results showed greater numbers of cEPCs in control and in diabetic patients treated with insulin plus metformin than in metformin-treated patients. Insulin plus metformin therapy was associated with augmented proliferative, clonogenicity, migratory, and tubulogenic activity of cEPCs in patients with T2DM. Increased serum concentrations of angiogenic factors were also observed in patients treated with insulin plus metformin. Western blot analysis showed increased protein levels of pTie-2/Tie2 and Pakt/AKT in cEPCs harvested from T2DM, treated with insulin metformin plus. This study showed that treatment with insulin plus metformin in diabetic patients is associated with increased mobilization of EPCs into the circulation, with potential beneficial effect in vascular protection in diabetic patients.

Pharmacogenetic influence of eNOS gene variant on endothelial and glucose metabolism responses to L-arginine supplementation: Post hoc analysis of the L-arginine trial

OBJECTIVE

To evaluate whether variants of the eNOS gene are associated with endothelial and metabolic responses to L-arginine (L-arg) supplementation.

MATERIAL AND METHODS

We examined a single nucleotide polymorphism of the eNOS gene (rs753482-A>C) to investigate the effects of this variant on endothelial function (EF), colony-forming unit-endothelial cell (CFU-EC) number, asymmetric-dimethylarginine (ADMA) level, insulin sensitivity index (ISI), and insulin secretion (IS) in a post hoc analysis of the L-arg trial. The L-arg trial (6.4 g/day for 18 months) was a single-center, randomized, double-blind, parallel-group, placebo-controlled, phase III trial in individuals with impaired glucose tolerance and metabolic syndrome. followed by a 12-month extended follow-up period after termination of the study drug (NCT 00917449).

RESULTS

At baseline, EF, CFU-EC numbers, ADMA levels, and ISI were impaired in subjects carrying minor allele C (both heterozygotes, AC and homozygotes, CC) as compared to subjects carrying major allele A (homozygotes, AA) (p<0.01). Compared to placebo, L-arg increased EF, CFU-EC numbers, and ISI, and improved ADMA levels and IS (p<0.01). The greatest improvements were found in AA subjects treated with L-arg, while the worst results were found in AC+CC subjects treated with placebo. In the placebo-treated subjects, EF, CFU-EC, ISI, and IS were significantly lower and ADMA was significantly higher in AC+CC subjects than in AA subjects.

CONCLUSIONS

Treatment with L-arg induced similar improvements in EF, CFU-EC numbers, ADMA levels, ISI, and IS in both AA subjects and AC+CC subjects. The presence of minor allele resulted in the worst prognosis in terms of EF, CFU-EC numbers, ADMA levels, ISI, and IS during the 30-month observation period.

Systematic review and meta-analysis of randomized clinical trials comparing efficacy and safety outcomes of insulin glargine with NPH insulin, premixed insulin preparations or with insulin detemir in type 2 diabetes mellitus

AIMS

A variety of basal insulin preparations are used to treat patients with type 2 diabetes mellitus (T2DM). We aimed to summarize scientific evidence on relative efficacy and safety of insulin glargine (IGlar) and other insulins in T2DM.

METHODS

A systematic review was carried out in major medical databases up to December 2012. Relevant studies compared efficacy and safety of IGlar, added to oral drugs (OAD) or/and in combination with bolus insulin, with protamine insulin (NPH) or premixed insulin (MIX) in the same regimen, as well as with insulin detemir (IDet), in T2DM. Target HbA1c level without hypoglycemic events was considered the primary endpoint.

RESULTS

Twenty eight RCTs involving 12,669 T2DM patients followed for 12-52 weeks were included in quantitative analysis. IGlar + OAD use was associated with higher probability of reaching target HbA1c level without hypoglycemia as compared to NPH + OAD (RR = 1.32 [1.09, 1.59]) or MIX without OAD (RR = 1.61 [1.22, 2.13]) and similar effect as IDet + OAD (RR = 1.07 [0.87, 1.33]) and MIX + OAD (RR = 1.09 [0.86, 1.38]). IGlar + OAD demonstrated significantly lower risk of symptomatic hypoglycemia as compared to NPH + OAD (RR = 0.89 [0.83, 0.96]), MIX + OAD (RR = 0.75 [0.68, 0.83]) and MIX without OAD(RR = 0.75 [0.68, 0.83]), but not with IDet + OAD (RR = 0.99 [0.90, 1.08]). In basal-bolus regimens, IGlar demonstrated similar proportion of T2DM patients achieving target HbA1c as compared to NPH (RR = 1.14 [0.91, 1.44]) but higher than MIX (RR = 1.26 [1.12, 1.42) or IDet (RR = 1.38 [1.11, 1.72]). The risk of severe hypoglycemia was lower in IGlar than in NPH (RR = 0.77 [0.63, 0.94]), with no differences in comparison with MIX (RR = 0.74 [0.46, 1.20]) and IDet (RR = 1.10 [0.54, 2.25]). IGlar + OAD has comparable safety profile to NPH, with less frequent adverse events leading to treatment discontinuation than MIX + OAD (RR = 0.41 [0.22, 0.76]) and IDet + OAD (RR = 0.40 [0.24, 0.69]). Also severe adverse reactions were less common for IGlar + OAD when compared to MIX + OAD (RR = 0.71 [0.52; 0.98]).

CONCLUSION

For the majority of examined efficacy and safety outcomes, IGlar use in T2DM patients was superior or non-inferior to the alternative insulin treatment options.