The association between aortic distensibility and coronary flow reserve in newly diagnosed diabetic patients

Parathyroid Hormone and Ischemic Cerebrovascular Event

BACKGROUND

Increased parathyroid hormone (PTH) level is associated with coronary artery disease, hypertension and left ventricular hypertrophy which are all predisposing factors for the ischemic cerebrovascular event (ICVE). Carotid intima-media thickness (CIMT) and aortic distensibility are the two early, subclinical predictors of atherosclerosis. The relation of PTH with CIMT and aortic distensibility in patients with ICVE has not been previously studied.

OBJECTIVE

Our aim was to study the relationship of PTH levels with aortic distensibility and CIMT in patients with ICVE.

METHODS

Sixty-four ICVE patients and 50 control group were enrolled in the study. PTH levels, aortic distensibility and CIMT were measured in all individuals.

RESULTS

PTH levels were significantly higher in ICVE patients than in the controls (60.1±21.6 vs. 52.3±6.2 pg/ml) (p=0. 008). PTH levels were found to be inversely correlated with aortic distensibility (r= -0. 420, p=0.001) and positively correlated with CIMT (r:0, 285, p=0,002).

CONCLUSION

The present study shows that PTH levels are increased in patients with acute ischemic cerebrovascular event compared to the control group. It also demonstrates that PTH levels are inversely related to aortic distensibility of ascending aorta and positively associated with CIMT.

Longer diabetes duration reduces myocardial blood flow in remote myocardium assessed by dynamic myocardial CT perfusion

AIMS

To investigate the relationship of type 2 diabetes duration and myocardial blood flow (MBF) assessed by myocardial CT perfusion.

MATERIALS AND METHODS

We prospectively included 140 patients with type 2 diabetes who underwent dynamic myocardial CT perfusion exam. MBF of the remote myocardium was calculated using the deconvolution technique and the Voronoi method. The relationships of MBF and diabetic duration, diabetic complications, conventional risk factors, coronary calcium, and coronary stenosis were assessed by logistic regression analysis.

RESULTS

A weak but significantly negative relationship was present between diabetes duration and MBF (R² = 0.05, p < 0.01). The average MBF of patients with a duration of >8 years was 13% lower than that of the remaining patients (1.11 ± 0.35 vs 1.28 ± 0.27 ml min^-1 g^-1, p < 0.01). Duration of one year was associated with a 6% increased risk for low MBF (<1.18 ml min^-1 g^-1) (odds ratio 1.06, 95% confidence interval 1.01-1.12, p < 0.05). Calcium score was also a significant factor for low MBF (odds ratio 1.08 (per 100 Agatston units), 95% confidence interval 1.01-1.17, p < 0.05).

CONCLUSION

Longer diabetes duration is associated with lower MBF independent of conventional cardiac risk factors or the presence of coronary stenosis.

Impaired coronary microcirculation in type 2 diabetic patients is associated with elevated circulating regulatory T cells and reduced number of IL-21R⁺ T cells

Background

Low-grade systemic inflammation is considered to participate in the progression of type 2 diabetes (T2D) and in diabetic complications.

Methods

To determine if circulating leukocytes were abnormally regulated in T2D patients, 8-color flow-cytometry (FACS) analysis was performed in a cross-sectional study of 37 T2D patients and 16 controls. Data obtained from the FACS analysis were compared to coronary flow reserve (CFR), assessed by Rb⁸²-PET-imaging, to uncover inflammatory signatures associated with impaired CFR.

Results

Presence of T2D was associated with T cell attenuation characterized by reduced overall T cell, Th17, IL-21R⁺, Treg’s and TLR4⁺ T cells, while the monocyte population showed enhanced TLR4 expression. Further, our data revealed reduced M1-like CD11c expression in T2D which was associated with impaired CFR. In contrast, we show, for the first time in T2D, increased TLR4 expression on CD8 T cells, increased Treg cell number and Treg maturation and reduced IL-21R expression on CD8 T cells to be functionally associated with impaired CFR.

Conclusions

Our demonstration that HbA1c inversely correlates to several T cell populations suggests that T cells may play disease modulating roles in T2D. Further, the novel association between impaired CFR and regulatory T cells and IL-21R⁺ T cells imply an intricate balance in maintaining tissue homeostasis in vascular diabetic complications.

Electronic supplementary material

The online version of this article (doi:10.1186/s12933-016-0378-5) contains supplementary material, which is available to authorized users.