Does endothelial function differ among sexes in patients with diabetes or kidney disease?

Abstract Background/introduction Endothelial dysfunction is a known driver of disease progression in both type 2 diabetes mellitus (T2DM) and kidney disease. Brachial artery flow-mediated dilation (FMD), representing endothelium-dependent nitric oxide-mediated dilation in response to increased shear stress, is considered gold standard to quantify macrovascular dysfunction non-invasively. As evidence is mounting that men are more likely to suffer from macrovascular dysfunction than women, we hypothesized that this would be reflected in patient populations with T2DM and/or kidney disease. Purpose To assess gender differences in macrovascular dysfunction, as measured by FMD, in patients with T2DM and/or kidney disease. Methods Preliminary baseline data was collected from two ongoing randomized controlled trials in patients with T2DM and in kidney transplant recipients (KTRs) 3 months post-transplantation. FMD was assessed with the semi-automated UNEX EF device under standardized conditions. Biochemical analyses were done using routine techniques. Images were manually analyzed by a single researcher (MR) using PCAnalysis software (version 1.0.14). Results Twenty-six subjects, 13 with T2DM and 12 KTRs were included. As expected, patients with T2DM had a higher BMI, higher HbA1c but higher eGFR compared to KTRs (Table 1). Compared to KTRs, patients with T2DM presented with a significantly worse FMD (FMD= 4.50% IQR=5.77 vs 10.88% 6.48). Overall, no significant difference in FMD between men and women was found (p=0.11), but higher values could be observed in females (FMD= 9.08% IQR=6.97 vs 4.50% 7.88). As depicted in Figure 2 this tendency was also observed in the two subgroups: KTR (M: FMD = 9.07% IQR=9.62 | F: 11.92% 5.16) and T2DM (M: FMD = 3.90% IQR=5.00% | F: 07.09% 6.83). Conclusion(s) Although no significant differences in vascular function between sexes were detected, our preliminary data showed a tendency for higher FMD-values in women; both in T2DM and KTRs. This supports the statement that male subjects seem to suffer more from macrovascular dysfunction. Further research is needed to elucidate the underlying pathways via which sex impacts the disease process in T2DM and kidney disease and to evaluate how personalized preventive lifestyle measures might differentially impact on outcome.