Coming Full Circle: Prioritizing Early Glycemic Control to Reduce Microvascular and Macrovascular Complications in People With Type 2 Diabetes

Association of dipeptidyl peptidase-4 inhibitor initiation at glycated haemoglobin <7.5% with reduced major clinical events mediated by low glycated haemoglobin variability

AIM

Therapeutic inertia, hypoglycaemia and poor treatment persistence can lead to glycaemic fluctuation and poor outcomes in type 2 diabetes (T2D). We compared glycated haemoglobin (HbA1c) variability, insulin initiation, severe hypoglycaemia and clinical events in patients with T2D initiated dipeptidyl peptidase-4 inhibitors (DPP4is) at low versus high HbA1c thresholds.

METHODS

Using territory-wide electronic medical records in Hong Kong, we curated a propensity score-matched cohort of patients initiated DPP4i at HbA1c <7.5% versus ≥7.5% in 2007-2019. We expressed the HbA1c variability score (HVS) as a proportion of HbA1c varied by ≥0.5% compared with preceding values. We used the Cox model to compare the risks of insulin initiation and clinical outcomes, adjusted for time-varying variables between the two groups. Mediation analysis estimated the effects of HbA1c variability on outcomes.

RESULTS

Among 6874 insulin-naïve patients who initiated DPP4i, 88.7% were treated with metformin and 79.6% with sulphonylureas at baseline (54.9% men; mean age 65.2 ± 11.4 years). After a median follow-up of 4.6 years, compared with the high-threshold plus high-HVS group (≥50%), the low-threshold plus low-HVS (<50%) group had reduced hazard ratios (95% confidence interval) of insulin initiation (0.35, 0.31-0.40), severe hypoglycaemia (0.38, 0.34-0.44), major adverse cardiovascular endpoints (0.76, 0.66-0.88), heart failure (0.42, 0.36-0.49), end-stage kidney disease (0.65, 0.36-0.49) and mortality (0.45, 0.35-0.57). Reduced HbA1c variability explained 31.1%-81.2% of the effect size of DPP4i initiation at HbA1c <7.5% versus ≥7.5% on outcomes.

CONCLUSIONS

In Chinese patients with T2D, avoiding therapeutic inertia with intensified glycaemic control at HbA1c <7.5% using drugs with low risk of hypoglycaemia and good tolerability, such as DPP4i, delayed insulin treatment, reduced HbA1c variability and improved clinical events.

Glycaemic control and macrovascular and microvascular outcomes in type 2 diabetes: Systematic review and meta-analysis of cardiovascular outcome trials of novel glucose-lowering agents

AIM

Using a systematic review and meta-analysis of placebo-controlled cardiovascular outcome trials (CVOTs) of newer glucose-lowering agents [sodium-glucose cotransporter-2 inhibitors (SGLT-2is), glucagon-like peptide-1 receptor agonists (GLP-1RAs), and dipeptidyl peptidase-4 inhibitors (DPP-4is)] in type 2 diabetes (T2D), we aimed to determine the macrovascular and microvascular outcomes of these agents and clarify the relationships between glycated haemoglobin (HbA1c) reduction and risk of these outcomes.

MATERIALS AND METHODS

Randomized controlled trials were identified from MEDLINE, Embase and the Cochrane Library until September 2023. Study-specific hazard ratios with 95% confidence intervals (CIs) were pooled, and meta-regression was used to assess the relationships between outcomes and between trial arm HbA1c reductions.

RESULTS

Twenty unique CVOTs (six SGLT-2is, nine GLP-1RAs, five DPP-4is), based on 169 513 participants with T2D, were eligible. Comparing SGLT-2is, GLP-1RAs and DPP-4is with placebo, the hazard ratios (95% CIs) for 3-point major adverse cardiovascular events were 0.88 (0.82-0.94), 0.85 (0.79-0.92) and 1.00 (0.94-1.06), respectively. SGLT-2is and GLP-1RAs consistently reduced the risk of several macrovascular and microvascular complications, particularly kidney events. DPP-4is showed no macrovascular benefits. There was potential evidence of an inverse linear relationship between HbA1c reduction and 3-point major adverse cardiovascular event risk (estimated risk per 1% reduction in HbA1c: 0.84, 95% CI 0.67-1.06; p = .14; R2 = 14.2%), which was driven by the component of non-fatal stroke (R2 = 100.0%; p = .094). There were non-significant inverse linear relationships between HbA1c reduction and the risk of several vascular outcomes.

CONCLUSIONS

SGLT-2is and GLP-1RAs showed consistent risk reductions in macrovascular and microvascular outcomes. The vascular benefits of SGLT-2is and GLP-1RAs in patients with T2D extend beyond mere glycaemic control.

Advances in secondary prevention mechanisms of macrovascular complications in type 2 diabetes mellitus patients: a comprehensive review

Type 2 diabetes mellitus (T2DM) poses a significant global health burden. This is particularly due to its macrovascular complications, such as coronary artery disease, peripheral vascular disease, and cerebrovascular disease, which have emerged as leading contributors to morbidity and mortality. This review comprehensively explores the pathophysiological mechanisms underlying these complications, protective strategies, and both existing and emerging secondary preventive measures. Furthermore, we delve into the applications of experimental models and methodologies in foundational research while also highlighting current research limitations and future directions. Specifically, we focus on the literature published post-2020 concerning the secondary prevention of macrovascular complications in patients with T2DM by conducting a targeted review of studies supported by robust evidence to offer a holistic perspective.

Microvascular complications identify a specific coronary atherosclerotic phenotype in patients with type 2 diabetes mellitus

Background

Patients with type 2 diabetes mellitus (T2DM) are considered as a homogeneous cohort of patients. However, the specific role of diabetic microvascular complications (DMC), in determining the features of coronary plaques is poorly known. We investigated whether the presence of DMC may identify a different phenotype of patients associated to specific clinical, angiographic, optical coherence tomography (OCT) features and different prognosis.

Methods

We prospectively enrolled consecutive T2DM patients with obstructive coronary artery disease (CAD) at their first coronary event. Patients were stratified according to the presence or absence of DMC, including diabetic retinopathy, diabetic neuropathy, and diabetic nephropathy. OCT assessment of the culprit vessel was performed in a subgroup of patients. The incidence of major adverse cardiac events (MACEs) was assessed at follow-up.

Results

We enrolled 320 T2DM patients (mean age 70.3 ± 8.8 years; 234 [73.1%] men, 40% acute coronary syndrome, 60% chronic coronary syndrome). Patients with DMC (172 [53.75%]) presented a different clinical and biochemical profile and, of importance, a higher prevalence of multivessel CAD (109 [63.4%] vs. 68 [45.9%], p = 0.002). At OCT analysis, DMC was associated to a higher prevalence of large calcifications and healed plaques and to a lower prevalence of lipid plaques. Finally, MACEs rate was significantly higher (25 [14.5%] vs. 12 [8.1%], p = 0.007) in DMC patients, mainly driven by a higher rate of planned revascularizations, and DMC predicted the occurrence of MACEs (mean follow-up 33.4 ± 15.6 months).

Conclusions

The presence of DMC identifies a distinct diabetic population with more severe CAD but with a more stable pattern of coronary atherosclerosis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12933-022-01637-y.