Type 1 diabetic patients have better endothelial function after simultaneous pancreas-kidney transplantation than after kidney transplantation with continued insulin therapy

Comprehensive review: Frailty in pancreas transplant candidates and recipients

Well-selected patients with kidney disease and diabetes mellitus who undergo simultaneous kidney-pancreas transplantation often experience dramatic improvements in quality of life and long-term survival compared to those who remain on medical therapy. Over the past several years the importance of frailty in the pancreas transplant candidate and recipient populations has grown. More patients with advanced age have entered the waitlist, and complications from prolonged diabetes, even in younger patients, have created increased evidence of risk for frailty. Given these concerns, and the broad challenges facing pancreas transplantation volumes overall, we generated this review to help establish the impact and implications. We summarize the interplay of immunological factors, aging, environmental factors, diabetes mellitus, and chronic kidney disease that put these patients at risk for frailty. We discuss its measurement and recommend a combination of two instruments (both well-validated and one entirely objective). We describe the outcomes for patients before and after pancreas transplantation who may have frailty, and what interventions can be taken to mitigate its effects. Broader investigation into frailty in the pancreas transplant population is needed to better understand how to select patients for pancreas transplantation and to how manage its consequences thereafter.

Beneficial Effect of Successful Simultaneous Pancreas-Kidney Transplantation on Plasma Profile of Metalloproteinases in Type 1 Diabetes Mellitus Patients

It is not fully elucidated whether the restoring of normal glucose metabolism after successful simultaneous pancreas-kidney transplantation (SPK) improves vascular wall morphology and function in type 1 diabetic (T1D) patients. Therefore, we compared arterial stiffness, assessed by pulse wave velocity (PWV), carotid intima-media thickness (IMT), and biomarkers of arterial wall calcification in T1D patients after SPK or kidney transplantation alone (KTA). In 39 SPK and 39 KTA adult patients of similar age, PWV, IMT, circulating matrix metalloproteinases (MMPs) and calcification biomarkers were assessed at median 83 months post transplantation. Additionally, carotid plaques were visualized and semi-qualitatively classified. Although PWV and IMT values were similar, the occurrence of atherosclerotic plaques (51.3 vs. 70.3%, p < 0.01) and calcified lesions (35.9 vs. 64.9%, p < 0.05) was lower in SPK patients. There were significantly lower concentrations of MMP-1, MMP-2, MMP-3, and osteocalcin in SPK subjects. Among the analyzed biomarkers, only logMMP-1, logMMP-2, and logMMP-3 concentrations were associated with log HbA_1c. Multivariate stepwise backward regression analysis revealed that MMP-1 and MMP-3 variability were explained only by log HbA_1c. Normal glucose metabolism achieved by SPK is followed by the favorable profile of circulating matrix metalloproteinases, which may reflect the vasoprotective effect of pancreas transplantation.

Type 1 diabetes patients increase CXCR4+ and CXCR7+ haematopoietic and endothelial progenitor cells with exercise, but the response is attenuated

Exercise mobilizes angiogenic cells, which stimulate vascular repair. However, limited research suggests exercise-induced increase of endothelial progenitor cell (EPCs) is completely lacking in type 1 diabetes (T1D). Clarification, along with investigating how T1D influences exercise-induced increases of other angiogenic cells (hematopoietic progenitor cells; HPCs) and cell surface expression of chemokine receptor 4 (CXCR4) and 7 (CXCR7), is needed. Thirty T1D patients and 30 matched non-diabetes controls completed 45 min of incline walking. Circulating HPCs (CD34⁺, CD34⁺CD45^dim) and EPCs (CD34⁺VEGFR2⁺, CD34⁺CD45^dimVEGFR2⁺), and subsequent expression of CXCR4 and CXCR7, were enumerated by flow cytometry at rest and post-exercise. Counts of HPCs, EPCs and expression of CXCR4 and CXCR7 were significantly lower at rest in the T1D group. In both groups, exercise increased circulating angiogenic cells. However, increases was largely attenuated in the T1D group, up to 55% lower, with CD34⁺ (331 ± 437 Δcells/mL vs. 734 ± 876 Δcells/mL p = 0.048), CD34⁺VEGFR2⁺ (171 ± 342 Δcells/mL vs. 303 ± 267 Δcells/mL, p = 0.006) and CD34⁺VEGFR2⁺CXCR4⁺ (126 ± 242 Δcells/mL vs. 218 ± 217 Δcells/mL, p = 0.040) significantly lower. Exercise-induced increases of angiogenic cells is possible in T1D patients, albeit attenuated compared to controls. Decreased mobilization likely results in reduced migration to, and repair of, vascular damage, potentially limiting the cardiovascular benefits of exercise.Trial registration: ISRCTN63739203.

Endothelial function after pancreas transplantation-A single-center observational study

BACKGROUND

Patients with diabetes mellitus treated with successful pancreas transplantation (PTX) normalize hyperglycemia, but are exposed to immunosuppressive drugs that may impair endothelial function. This study aimed to evaluate endothelial function in single PTX recipients.

METHODS

Flow-mediated dilatation (FMD) in the brachial artery was measured by ultrasound 8 weeks after transplantation in single PTX (n = 27) and compared with healthy controls (n = 58), simultaneous pancreas and kidney recipients (n = 9), and kidney transplant recipients with (n = 41) and without (n = 95) diabetes mellitus. Adjustments for age, gender, blood pressure, and body mass index were included in a linear regression model. Changes in FMD from before to 1 year after transplantation were assessed in a subgroup of PTX recipients (n = 9).

RESULTS

Flow-mediated dilatation% in PTX recipients was not inferior to healthy controls (8.7 ± 3.6 vs 7.7 ± 3.3, P = .06) and simultaneous pancreas and kidney recipients (6.7 ± 4.5, P = .24) in an adjusted model, and superior to kidney recipients with and without diabetes (3.0 ± 3.0 and 4.8 ± 3.3, respectively, both P < .005). FMD% improved significantly from eight weeks to one year after PTX, mean 7.9 ± 4.2% vs 11.8 ± 4.8% (N = 9; P = .03).

CONCLUSION

Flow-mediated dilatation is well preserved in patients undergoing pancreas transplantation and is not impaired when immunosuppressive drugs are introduced.