The clinical consequences of obesity on the kidneys, with or without metabolic abnormalities, involve both renal function and structures. The mechanisms linking obesity and renal damage are well understood, including several effector mechanisms with interconnected pathways. Higher prevalence of urinary albumin excretion, sub-nephrotic syndrome, nephrolithiasis, increased risk of developing CKD, and progression to ESKD have been identified as being associated with obesity and having a relevant clinical impact. Moreover, renal replacement therapy and kidney transplantation are also influenced by obesity. Losing weight is key in limiting the impact that obesity produces on the kidneys by reducing albuminuria/proteinuria, declining rate of eGFR deterioration, delaying the development of CKD and ESKD, and improving the outcome of a renal transplant. Weight reduction may also contribute to appropriate control of cardiometabolic risk factors such as hypertension, metabolic syndrome, diabetes, and dyslipidemia which may be protective not only in renal damage but also cardiovascular disease. Lifestyle changes, some drugs, and bariatric surgery have demonstrated the benefits.

There is increasing interest in using extracellular vesicle-derived microRNAs (miRNAs) as biomarkers in renal dysfunction and injury. Preliminary evidence indicates that miRNAs regulate the progression of glomerular disease. Indeed, exosomes from the renal system have provided novel evidence in the clinical setting of albuminuria. Thus, the aim of this study was to quantify the urinary miRNAs present in exosome and microvesicles (MVs), and to assess their association with the presence of increased urinary albumin excretion in essential hypertension. Exosomes were collected from urine specimens from a cohort of hypertensive patients with (n = 24) or without albuminuria (n = 28), and from 20 healthy volunteers as a control group. Urinary exosomes were phenotyped by Western blot, tunable resistive pulse sensing, and electronic microscopy. Expression of miR-146a and miR-335* was analysed by qRT-PCR and any associations between albuminuria and exosomal miRNAs were analysed. Urinary miRNAs are highly enriched in exosome subpopulations compared to MVs, both in patients with or without increased albuminuria (p < 0.001), but not in the control group. High albuminuria was associated with 2.5-fold less miR-146a in exosomes (p = 0.017), whereas miR-146a levels in MV did not change. In addition, exosome miR-146a levels were inversely associated with albuminuria (r = 0.65, p < 0.0001), and discriminated the presence of urinary albumin excretion presence [area under the curve = 0.80, 95% confidence interval: 0.66–0.95; p = 0.0013]. Our results indicate that miRNAs were enriched in the urinary exosome subpopulation in hypertensive patients and that low miR-146a expression in exosomes was associated with the presence of albuminuria. Thus, urinary exosome miR-146a may be a potentially useful tool for studying early renal injury in hypertension.

Urinary albumin excretion (UAE) is a marker of cardiovascular risk and renal damage in hypertension. MicroRNAs (miRNAs) packaged into exosomes function as paracrine effectors in cell communication and the kidney is not exempt. This study aimed to state an exosomal miRNA profile/signature associated to hypertension with increased UAE and the impact of profibrotic TGF-β1 (transforming growth factor β1) on exosomes miRNA release. Therefore, exosomes samples from patients with hypertension with/without UAE were isolated and characterized. Three individual and unique small RNA libraries from each subject were prepared (total plasma, urinary, and plasma-derived exosomes) for next-generation sequencing profiling. Differentially expressed miRNAs were over-represented in Kyoto Encyclopedia of Genes and Genomes pathways, and selected miRNAs were validated by real-time quantitative polymerase chain reaction in a confirmation cohort. Thus, a signature of 29 dysregulated circulating miRNAs was identified in UAE hypertensive subjects, regulating 21 pathways. Moreover, changes in the levels of 4 exosomes-miRNAs were validated in a confirmation cohort and found associated with albuminuria. In particular miR-26a, major regulator of TGF-β signaling, was found downregulated in both type of exosomes when compared with healthy controls and to hypertension normoalbuminurics ( P <0.01). Similarly, decreased miR-26a levels were found in podocyte-derived exosomes after TGF-β stress. Our results revealed an exosomes miRNA signature associated to albuminuria in hypertension. In particular, exosomes miR-26a seemed to play a key role in the regulation of TGF-β, a relevant effector in podocyte damage. These findings support the use of exosomes miRNAs as biomarkers of cardiovascular risk progression and therapeutic tools in early kidney damage.

The objective was to assess the role of office and ambulatory blood pressure (BP) on the development of end-stage renal disease (ESRD) in nondiabetic chronic renal failure. Seventy-nine patients [mean age 57 (standard deviation 11) years, 47 men, BMI 28 (4), office BP 151 (25)/92 (14) mmHg, estimated glomerular filtration rate 28 (14) ml/min per 1.73 m3] were included. The causes of renal disease were nephrosclerosis (n = 33), glomerulonephritis (n = 19), interstitial (n = 12) and others (n = 15). The average follow-up was 44 months (range 9-72 months). The primary outcome was a composite of death, from any cause, or the development of ESRD that require initiation of renal replacement therapy. In all patients, 24-h ambulatory BP monitoring and left ventricular mass assessment were performed at the beginning of the study. During the follow-up period, 41 (52%) patients progressed to ESRD. In addition, nine (11%) patients died, four before reaching ESRD. Then the combined endpoint rate, 45 patients, was 6.3/100 patients per year. In a multivariate Cox proportional hazard model, which includes age, sex, angiotensin-converting enzyme inhibitor/angiotensin II receptor blocker status and the estimated glomerular filtration rate, office BP still provided no further prognostic information on risk of the primary outcome. In addition, daytime ambulatory BP and the no-dipper status did not further discriminate in terms of predicting endpoint. Nocturnal SBP more than 130 mmHg was associated with a doubling of risk [heart rate 2.07 (95% confidence interval 1.01-4.25)] on top of the other significant factors. Glomerular filtration rate and nocturnal SBP values, but not nondipper pattern, were associated with risk to develop ESRD.

Objective We assessed the relationship between pulse pressure and intermediate cardiovascular phenotypes in a middle-aged cohort with high prevalence of hypertension. Background It has been suggested that central pulse pressure (cPP) is a better predictor of cardiovascular outcome than peripheral pulse pressure (pPP), particularly in the elderly. Yet, it is unclear if cPP provides additional prognostic information to pPP in younger individuals. Methods In 535 individuals we assessed cPP and pPP as well as the intermediate cardiovascular phenotypes pulse wave velocity (PWV; SphygmoCor, Complior, PulsePen), carotid intima-media thickness (C-IMT; carotid ultrasound), left-ventricular mass index (LVMI; echocardiography) and urinary albumin : creatinine ratio (ACR). cPP was derived noninvasively from brachial blood pressure by pulse wave analysis (PWA; SphygmoCor) based on radial pulse wave tonometry and a validated transfer function. Results The cohort contained 331 hypertensive participants of whom 84% were treated. The average age was 46 ± 16 years. When compared to pPP, cPP had stronger associations with PWV (r = 0.471 vs. r = 0.372; P < 0.01), C-IMT (r = 0.426 vs. r = 0.235; P < 0.01) and LVMI (r = 0.385 vs. r = 0.189; P < 0.01), but equal association with ACR (r = 0.236 vs. r = 0.226; P = n.s.). In contrast, after adjustment for age, mean arterial pressure, heart rate and hypertension status there was no significant difference between cPP and pPP for prediction of PWV (adjusted R², 0.399 vs. 0.413; P = 0.066), C-IMT (adjusted R², 0.399 vs. 0.413; P = 0.487) and LVMI (adjusted R², 0.181 vs. 0.170; P = 0.094) in multivariate analysis. Conclusion In our middle-aged cohort with high prevalence of hypertension cPP is more closely correlated with cardiovascular phenotypes than pPP. When adjusted for relevant cofactors, however, cPP does not provide additional information beyond pPP.