Garovic, Vesna D.

ABSTRACT Background: An increased number of podocyte-derived extracellular vesicles (pEVs) may reflect podocyte injury in renal disease. Elevated glomerular pressure and other insults may injure podocytes, yet it remains unclear whether the numbers of pEVs are altered in hypertensive patients. We tested the hypothesis that urinary pEV levels would be elevated in patients with renovascular hypertension (RVH) compared with essential hypertension (EH) or healthy volunteers (HVs). Methods: We prospectively enrolled patients with EH (n = 30) or RVH (n = 31) to study renal blood flow (RBF) and cortical perfusion using multidetector computed tomography under controlled condition (regulated sodium intake and renin—angiotensin blockade). After isolation from urine samples, pEVs (nephrin and podocalyxin positive) were characterized by flow cytometry. Fourteen RVH patients were studied again 3 months after stenting or continued medical therapy. HVs (n = 15) served as controls. Results: The fraction of pEV among urinary EVs was elevated in RVH compared with HVs and EH (11.4 ± 6.4, 6.8 ± 3.4 and 6.3 ± 3.7%, respectively; P < 0.001) and remained unchanged after 3 additional months of therapy and after controlling for clinical parameters. However, eGFR- and age-adjusted pEV levels did not correlate with any clinical or renal parameters. Conclusions: In hypertensive patients under controlled conditions, urinary pEV levels are elevated in patients with RVH and low eGFR compared with patients with EH and relatively preserved renal function. These pEVs may reflect podocyte injury secondary to kidney damage, and their levels might represent a novel therapeutic target.

Background— Hypertensive pregnancy disorders have been associated with subjective cognitive complaints or brain white-matter lesions 5 to 10 years after the hypertensive pregnancy. The long-term effects of hypertensive pregnancies on brain structure and cognitive function remain unknown. Methods and Results— This study included 1279 women who participated in the Family Blood Pressure Project Genetic Epidemiology Network of Arteriopathy (GENOA) study. As part of the ancillary Genetics of Microangiopathic Brain Injury (GMBI) study, a neurocognitive battery was administered; 1075 also had a brain magnetic resonance imaging. A history of a hypertensive pregnancy disorder was obtained by a self-report using a validated questionnaire. Linear models fit with generalized estimating equations were used to assess the association between hypertensive pregnancy disorders and cognition, adjusting for age, race, education, body mass index, smoking, current hypertension, hypertension duration, and family history of hypertension. Regression models for the brain magnetic resonance imaging outcomes also were adjusted for total intracranial volume. Women with histories of hypertensive pregnancy disorders performed worse on all measures of processing speed (Digital Symbol Substitution Test [mean score, 41.2 versus 43.4; P =0.005], Trail Making Test Part A [mean seconds, 45.1 versus 42.2; P =0.035], and Stroop [mean score, 173.9 versus 181.0; P =0.002]) and had smaller brain volumes compared with women with histories of normotensive pregnancies (286 versus 297; P =0.023). Conclusions— Hypertensive pregnancy disorders are associated with worse performance on tests of processing speed and smaller brain volumes decades later. Population-based studies are needed to provide critical insight as to the contribution of hypertensive pregnancies to risk of cognitive decline and dementia.

Endothelial dysfunction is believed to play a critical role in preeclampsia; however, it is unclear whether this dysfunction precedes the pregnancy or is caused by pathophysiological events in early pregnancy. It is also unclear for how long vascular dysfunction may persist postpartum and whether it represents a mechanism linking preeclampsia with future cardiovascular disease. Our objective was to determine whether women with preeclampsia had worse vascular function compared with women who did not have preeclampsia by performing a systematic review and meta-analysis of studies that examined endothelial dysfunction using flow-mediated dilation. We included studies published before May 29, 2015, that examined flow-mediated dilation before, during, or after preeclampsia. Differences in flow-mediated dilation between study groups were evaluated by standardized mean differences. Out of 610 abstracts identified through PubMED, EMBASE, and Web of Science, 37 studies were eligible for the meta-analysis. When compared with women who did not have preeclampsia, women who had preeclampsia had lower flow-mediated dilation before the development of preeclampsia (≈20–29 weeks gestation), at the time of preeclampsia, and for 3 years postpartum, with the estimated magnitude of the effect ranging between 0.5 and 3 standard deviations. Similar effects were observed when the analysis was limited to studies that excluded women with chronic hypertension, smokers, or both. Vascular dysfunction predates preeclampsia and may contribute to its pathogenesis. Future studies should address whether vascular changes that persist after preeclamptic pregnancies may represent a mechanistic link with increased risk for future cardiovascular disease.

Objective Cardiac changes of hypertensive pregnancy include left ventricular hypertrophy (LVH) and diastolic dysfunction. These are thought to regress postpartum. We hypothesised that women with a history of hypertensive pregnancy would have altered LV geometry and function when compared with women with only normotensive pregnancies. Methods In this cohort study, we analysed echocardiograms of 2637 women who participated in the Family Blood Pressure Program. We compared LV mass and function in women with hypertensive pregnancies with those with normotensive pregnancies. Results Women were evaluated at a mean age of 56 years: 427 (16%) had at least one hypertensive pregnancy; 2210 (84%) had normotensive pregnancies. Compared with women with normotensive pregnancies, women with hypertensive pregnancy had a greater risk of LVH (OR: 1.42; 95% CI 1.01 to 1.99, p=0.05), after adjusting for age, race, research network of the Family Blood Pressure Program, education, parity, BMI, hypertension and diabetes. When duration of hypertension was taken into account, this relationship was no longer significant (OR: 1.19; CI 0.08 to 1.78, p=0.38). Women with hypertensive pregnancies also had greater left atrial size and lower mitral E/A ratio after adjusting for demographic variables. The prevalence of systolic dysfunction was similar between the groups. Conclusions A history of hypertensive pregnancy is associated with LVH after adjusting for risk factors; this might be explained by longer duration of hypertension. This finding supports current guidelines recommending surveillance of women following a hypertensive pregnancy, and sets the stage for longitudinal echocardiographic studies to further elucidate progression of LV geometry and function after pregnancy. Clinical trial registrations GENOA- NCT00005269; HyperGEN- NCT00005267; Sapphire- NCT00005270; GenNet- NCT00005268.

Free vascular endothelial growth factor (VEGF) is undetectable in plasma during human pregnancy. However, studies examining pregnant rats have reported both low (8–29 pg/ml) and high (527–1,030 pg/ml) free VEGF. These discrepancies cast uncertainty over the use of rat models to study angiogenic factors in pregnancy and preeclampsia. This study investigates methodological factors that may explain these discrepancies. Plasma VEGF in nonpregnant, day 7 pregnant, and day 19 pregnant rats was measured using rat and mouse ELISAs (R&D Systems). The rat ELISA detected VEGF in plasma from nonpregnant rats but not in plasma from day 19 pregnant rats. The mouse ELISA detected higher VEGF concentrations than the rat ELISA in every sample tested. This discrepancy was greater in day 19 pregnant rats (median: 2,273 vs. 0 pg/ml) than in nonpregnant (97 vs. 20 pg/ml) and day 7 pregnant (66 vs. 2 pg/ml) rats. Recovery of recombinant rat VEGF (rrVEGF) spiked into plasma from nonpregnant and day 7 pregnant rats was high for the rat ELISA (82–105%) but low for the mouse ELISA (17–22%). The rat ELISA did not recover rrVEGF in plasma from day 19 pregnant rats, suggesting that this ELISA measures free VEGF. The use of the rat versus mouse ELISA likely explains the differences in reported VEGF concentrations in pregnant rats. While the rat ELISA appears to measure free VEGF, plasma concentrations in nonpregnant and pregnant rats are below the assay sensitivity limit. As most previous studies of pregnant rats used the mouse VEGF ELISA, these data should be interpreted cautiously.