No detectable differential microRNA expression between non-atherosclerotic arteries of type 2 diabetic patients (treated or untreated with metformin) and non-diabetic patients

Can miR-145-5p be used as a marker in diabetic patients?

In the light of emerging global epidemics of type 2 diabetes mellitus significant efforts are continuing to discover novel biomarkers for early detection of the disease. Since miRNAs play an important role in both the initiation and progress of many pathologic processes such as diabetes, in this study we aimed to evaluate expression level of plasma miR-145-5p in diabetics and pre-diabetics in comparison to the control group and assess its use as a biomarker in diagnosis of T2D. The plasma level of miR-145-5p was assessed in three groups including 20 prediabetic patients, 20 T2D patients and 20 healthy controls using RT-qPCR. Biochemical parameters were also measured by the auto-analyzer. Expression level of miR-145-5p was down-regulated in the prediabetics and the T2D patients compared to the controls. In the control group miR-145-5p showed a borderline correlation with FBS (p = .06), while in the prediabetic group miR-145 showed a significant negative correlation with FBS and finally in the T2D patients miR-145 was negatively correlated with HbA1c and TC and showed a negative borderline correlation with FBS. The ROC analysis indicated a significant ability for miR-145-5p in discriminating between the diabetics and pre-diabetics from the healthy subjects. Our results demonstrated that the miR-145-5p expression level is deregulated in the diabetics and the prediabetics. Furthermore miR-145-5p displayed a significant ability to discriminate the diabetics from the healthy subjects. These results suggest that miR-145-5p may be a useful biomarker for the diagnosis of T2DM.

Metformin therapy in patients with diabetes mellitus is associated with a reduced risk of vasculopathy and cardiovascular mortality after heart transplantation

Background

Cardiac allograft vasculopathy (CAV) is a major cause of morbidity and mortality following heart transplantation (HT). Reduced cardiovascular mortality and morbidity have been reported in non-HT patients treated with metformin. Given the high prevalence of type 2 diabetes mellitus (T2DM) in HT patients, we investigated the association between metformin therapy and cardiovascular outcomes after HT.

Methods

The study population comprised 103 DM patients who had undergone HT between 1994 and 2018 and were prospectively followed-up. We excluded from the study patients with type 1 diabetes mellitus. Fifty-five HT patients (53%) in the cohort were treated with metformin. Clinical data were recorded on prospectively designed forms. The primary outcomes included CAV, survival, and the combined end-point of CAV or cardiovascular mortality.

Results

Kaplan–Meier survival analysis showed that the CAV rate at 20 years of follow-up was lower in DM patients treated with metformin than in those who were not (30 vs. 65%; log-rank p = 0.044). Similarly, the combined risk of CAV or cardiovascular mortality was lower in the metformin-treated patients than in those not receiving metformin (32 vs. 68%; log rank p = 0.01). Consistently, multivariate analysis adjusted for age and comorbidities showed that metformin therapy was independently associated with a significant 90% reduction (95% confidence interval 0.02–0.46, p = 0.003) in the risk for the development of CAV, and a 91% reduction (95% confidence interval 0.02–0.42; p = 0.003) in the risk for CAV or cardiovascular mortality.

Conclusions

In diabetic HT patients, metformin therapy is independently associated with a significant reduction in the long-term risk for CAV and the combined end-point of CAV or cardiovascular mortality after HT.