Sola Aoun Bahous

Aortic Stiffness, Living Donors, and Renal Transplantation

In subjects with renal disease, reduced renal function and increased arterial stiffness are significantly associated in cross-sectional studies. The relationship is independent of age, blood pressure (BP), and atherosclerosis. Because both variables are independent predictors of cardiovascular risk, time-dependent relationships between them are important to determine. Aortic pulse wave velocity was measured noninvasively by comparison with healthy volunteers in 101 living kidney donors and their 101 corresponding recipients. Healthy volunteers were divided into 2 groups: one was recipient related through familial links and the other was nonrecipient related. Independently of age, gender, and BP, pulse wave velocity was significantly elevated in donors and recipients by comparison with the 2 groups of healthy volunteers. Pulse wave velocity was significantly higher in the recipient-related than in the nonrecipient-related group. Whereas in healthy volunteers, pulse wave velocity was exclusively related to age, gender, and BP, in donors and recipients, it was rather associated with a cluster of cardiovascular risk factors, including smoking habits and plasma glucose. Major factors related to pulse wave velocity were renal: time since nephrectomy (donation date) in donors, in whom pulse pressure was specifically associated with proteinuria, and renal rejection in recipients. Plasma creatinine doubling secondary to chronic allograft nephropathy was significantly associated with renal rejection and donor pulse wave velocity, independent of age. Our findings strongly suggest consistent interactions (including familial factors) between kidney function and arterial stiffness. Assessment of cause–effect relationships and implication of biochemical and/or genetic factors warrant additional studies.

Cardiovascular and renal outcome in recipients of kidney grafts from living donors: role of aortic stiffness

BACKGROUND Cardiovascular (CV) risk remains high in renal transplant patients despite a clear improvement conferred by transplantation. This risk is attributed mostly to recipient-related risk factors. Donor vascular characteristics, such as arterial stiffness, have been poorly investigated in this regard. METHODS Recipients of living-related (n = 75) and living-unrelated (n = 20) kidney grafts were recruited at a mean time of 107 ± 41 months after transplantation for baseline evaluation and follow-up for the occurrence of the following composite outcome: myocardial infarction, stroke, CV death, doubling of serum creatinine or development of end-stage renal disease (ESRD). At inclusion, recipients and their corresponding donors underwent complete history, physical examination, laboratory tests and non-invasive measurement of aortic pulse wave velocity (PWV). RESULTS During a mean follow-up of 56 ± 18 months, 20 recipients doubled their serum creatinine, of whom 16 reached ESRD, and 9 suffered of a new CV event (5 of which were fatal). Cox proportional hazards regression analysis showed that, in addition to recipient-related parameters, such as the presence of CV event and the estimated glomerular filtration rate at inclusion, donor aortic PWV was a strong and independent predictor of the composite recipient outcome. CONCLUSIONS Donor large artery stiffness may predict recipient CV and graft outcome. This finding demonstrates the tight link that exists between the vascular system and the kidneys and suggests that donor contribution to recipient outcome goes beyond simple parameters like age, gender and even familial or non-familial donor type.

Change in Pulse Wave Velocity and Short-Term Development of Cardiovascular Events in the Hemodialysis Population

The association between single measurements of carotid‐femoral pulse wave velocity (cfPWV) and cardiovascular (CV) events is driven by late events beyond 12 months of follow‐up. This prospective study compares single measurements of cfPWV vs the 2‐year delta cfPWV and the association with short‐term development of CV events in hemodialysis patients. cfPWV was performed at t=0 and t=1 two years later, and patients were followed‐up for development of CV events through 12 months (n=66). In Cox regression models adjusted for CV risk factors, history of CV events and delta cfPWV remained associated with the development of CV events (hazard ratio for prior CV events=8.9, P=.03; hazard ratio for delta cfPWV=1.14; P=.002). When delta cfPWV was substituted for single cfPWV measurement, none of the single measures were associated with new CV events. The change in cfPWV, but not single measurements of cfPWV, was associated with the development of CV events through 12 months.

Renal Function Decline in Recipients and Donors of Kidney Grafts: Role of Aortic Stiffness

Background/Aims: Renal function decreases over time as a result of reduction in the number of functioning nephrons with age. In recipients and donors of kidney grafts, renal function decline may be linked differently to various parameters, namely arterial stiffness. Methods: We conducted a prospective cohort study including 101 recipients of kidney grafts and their donors aiming at determining the factors correlated to the renal function decline over time. Aortic stiffness was evaluated by the non-invasive measurement of aortic pulse wave velocity. The glomerular filtration rate was estimated using the Modification of Diet in Renal Disease (MDRD) equation and the annualized change was determined. Results: Decline in renal function was estimated at 1-year post-transplantation and annually thereafter (median follow-up 8 years, range 3.6-18.3), as the mean of the annualized decrease in the glomerular filtration rate. In recipients, filtration rate decreased by 4.8 ± 19.7 ml/min/1.73 m2 the first post-transplant year and at a yearly rate of 2.2 ± 3.8 ml/min/1.73 m2 thereafter. The first-year decline was related to smoking and acute rejection. Later decline was significantly associated with donor age and aortic stiffness. In living donors, renal function decline after the first year corresponded to 0.7 ml/min/1.73 m2, was significantly lower than that of recipients (p < 0.001), and was determined by donor age at nephrectomy. Conclusion: Recipients of kidney grafts show a glomerular filtration rate decline over time that is significantly associated with donor age and aortic stiffness after the first post-transplant year, while donors demonstrate a lower decline that is mostly determined by age at nephrectomy.

Sickle cell nephropathy: an update on pathophysiology, diagnosis, and treatment

Sickle cell nephropathy is a major complication of sickle cell disease. It manifests in different forms, including glomerulopathy, proteinuria, hematuria, and tubular defects, and frequently results in end-stage renal disease (ESRD). Different pathophysiologic mechanisms have been proposed to explain the development of nephropathy in SCD, where hemolysis and vascular occlusion are the main contributors in the manifestations of this disease. Markers of renal injury, such as proteinuria and tubular dysfunction, have been associated with outcomes among patients with sickle cell nephropathy and provide means for early detection of nephropathy and screening prior to progression to renal failure. In small-sized clinical trials, hydroxyurea has demonstrated to be effective in slowing the progression to ESRD. Dialysis and renal transplantation represent the last resort for patients with sickle cell nephropathy. Nevertheless, despite the availability of diagnostic and therapeutic strategies, sickle cell nephropathy remains a challenging and under-recognized complication for patients with sickle cell disease.

Longitudinal Study of Hypertensive Subjects With Type 2 Diabetes MellitusNovelty and Significance: Overall and Cardiovascular Risk

Despite adequate glycemic and blood pressure control, treated type 2 diabetic hypertensive subjects have a significantly elevated overall/cardiovascular risk. We studied 244 816 normotensive and 99 720 hypertensive subjects (including 7480 type 2 diabetics) attending medical checkups between 1992 and 2011. We sought to identify significant differences in overall/cardiovascular risk between hypertension with and without diabetes mellitus. Mean follow-up was 12.7 years; 14 050 all-cause deaths were reported. From normotensive to hypertensive populations, a significant progression in overall/cardiovascular mortality was observed. Mortality was significantly greater among diabetic than nondiabetic hypertensive subjects (all-cause mortality, 14.05% versus 7.43%; and cardiovascular mortality, 1.28% versus 0.7%). No interaction was observed between hemodynamic measurements and overall/cardiovascular risk, suggesting that blood pressure factors, even during drug therapy, could not explain the differences in mortality rates between diabetic and nondiabetic hypertensive patients. Using cross-sectional regression models, a significant association was observed between higher education levels, lower levels of anxiety and depression, and reduced overall mortality in diabetic hypertensive subjects, while impaired renal function, a history of stroke and myocardial infarction, and increased alcohol and tobacco consumption were significantly associated with increased mortality. Blood pressure and glycemic control alone cannot reverse overall/cardiovascular risk in diabetics with hypertension. Together with cardiovascular measures, overall prevention should include recommendations to reduce alcohol and tobacco consumption and improve stress, education levels, and physical activity.

Country of birth affects blood pressure in the French hypertensive diabetic population

In a population of 56,242 individuals living in France, we showed that individuals born in France have significantly different levels of blood pressure (BP) and cardiovascular (CV) risk factors than African and Asian populations born in their own country but living long-term in France (average duration of stay, 5–10 years). The objective of our study was to investigate the impact of country of birth on BP and CV risk factors in a subpopulation of 9245 patients selected solely on the diagnosis of hypertension, either alone or with simultaneous type 2 diabetes. In the subgroup of individuals with hypertension alone, brachial systolic, diastolic, mean and pulse pressure (PP), heart rate (HR), augmentation index and PP amplification were significantly higher in African-born than French- and Asian-born populations. In the subgroup of individuals with both hypertension and diabetes, only augmentation index, PP amplification and brachial and central PP, but not brachial systolic, diastolic, mean BP, and HR, were elevated when the African-born subgroup was compared to the French- and Asian-born populations. Increased body mass index (BMI), waist-hip ratio (WHR), and deprivation scores, but not increased plasma lipids or glycemia, were consistently associated with the African-born population. The combination of diabetes and hypertension in African populations was associated with increased aortic stiffness and PP, together with greater body weight and WHR. In individuals with increased PP and hence systolic hypertension, increased PP requires systolic BP to be reduced whereas notable reductions in diastolic BP may have deleterious consequences.

Influence of standardized patient body habitus on undergraduate student performance in an Objective Structured Clinical Examination

Purpose: Previous studies have shown that the standardized patients (SP) gender may affect student performance in an Objective Structured Clinical Examination (OSCE). The aim of this study is to investigate the influence of the SPs’ body habitus on students’ performance in an OSCE counseling station. Methods: Four equally trained female SPs, with either a normal or an obese BMI participated in an OSCE counseling station for cardiovascular risk factors. Ninety-two, second year medical students were randomly assigned to one of the SPs. Station scores were compared and student behavior and opinion regarding the influence of their SPs body habitus on their performance was assessed. Results: There was no difference in mean exam scores for students interacting with SPs with a normal BMI versus increased BMI (14.9 ± 2.2 versus 14.01 ± 2.2/20 respectively, p = 0.06). Additionally, almost all students gave advice about healthy diets (93.5% versus 95.7%) with no specificity regarding the BMI of the SP. Conclusions: The body habitus of the SP did not significantly affect students’ performance in an undergraduate OSCE about cardiovascular risk factors, suggesting that students at that level may primarily focus on gaining points the diagnostic checklist without considering SPs as real patients.