Changes in renal autacoids and hemodynamics associated with aging and isolated systolic hypertension

Acute renal impairment in older adults treated with percutaneous coronary intervention for ST-segment elevation myocardial infarction

BACKGROUND

Elderly individuals ( ≥ 75 years) constitute an increasing proportion of patients presenting with myocardial infarction treated with primary percutaneous coronary intervention (PCI), but only limited data are available regarding the incidence and prognostic implications of acute kidney injury (AKI) in this group of patients.

OBJECTIVE

To evaluate the incidence and prognostic implications of AKI in older adults ( ≥ 75 years) with ST-segment elevation myocardial infarction (STEMI) treated with primary PCI.

PATIENTS AND METHODS

A retrospective cohort, observational, single-center study of consecutive 416 older patients with STEMI (≥ 75 years) treated with primary PCI between January 2008 and August 2017 was conducted. AKI was defined as an increase of at least 0.3 mg/dl in serum creatinine within 48 h following admission.

RESULTS

A total of 96/416 (23%) patients developed AKI. The occurrence of AKI was associated with adverse in-hospital outcomes, higher 30 days (25 vs. 6%; P < 0.001), and long-term mortality (46 vs. 17%; hazard ratio: 3.2; 95% confidence interval: 2.1-4.7; P < 0.001). Among patients with AKI, 46/96 (48%) demonstrated recovery of renal function at hospital discharge. Lack of renal function recovery at discharge (50/96 patients; 52%) was associated with the occurrence of new or progression of baseline chronic kidney disease.

CONCLUSION

Among older patients with STEMI undergoing primary PCI, AKI is a frequent complication associated with adverse renal short-term and long-term outcomes.

Retinal pigment epithelium response to oxidant injury in the pathogenesis of early age-related macular degeneration

Age-related macular degeneration (AMD) represents the leading cause of vision loss in the elderly. Accumulation of lipid- and protein-rich deposits under the retinal pigment epithelium (RPE) heralds the onset of early AMD, but the pathogenesis of subretinal deposit formation is poorly understood. Numerous hypothetical models of deposit formation have been proposed, including hypotheses for a genetic basis, choroidal hypoperfusion, abnormal barrier formation, and lysosomal failure. This review explore the RPE injury hypothesis, characterized by three distinct stages (1) Initial RPE oxidant injury, caused by any number of endogenous or exogenous oxidants, results in extrusion of cell membrane "blebs," together with decreased activity of matrix metalloproteinases (MMPs), promoting bleb accumulation under the RPE as basal laminar deposits (BLD). (2) RPE cells are subsequently stimulated to increase synthesis of MMPs and other molecules responsible for extracellular matrix turnover (i.e., producing decreased collagen), affecting both RPE basement membrane and Bruchs membrane (BrM). This process leads to progression of BLD into basal linear deposits (BLinD) and drusen by admixture of blebs into BrM, followed by the formation of new basement membrane under the RPE to trap these deposits within BrM. We postulate that various hormones and other plasma-derived molecules related to systemic health cofactors are implicated in this second stage. (3) Finally, macrophages are recruited to sites of RPE injury and deposit formation. The recruitment of nonactivated or scavenging macrophages may remove deposits without further injury, while the recruitment of activated or reparative macrophages, through the release of inflammatory mediators, growth factors, or other substances, may promote complications and progression to the late forms of the disease.

Acute kidney injury in the elderly

The aging kidney undergoes several important anatomic and physiologic changes that increase the risk of acute kidney injury (formerly acute renal failure) in the elderly. This article reviews these changes and discusses the diagnoses frequently encountered in the elderly patient with acute kidney injury. The incidence, staging, evaluation, management, and prognosis of acute kidney injury are also examined with special focus given to older adults.

Glomerular Filtration Rate and Albumin Excretion After Maximal Exercise in Aging Sedentary and Active Men

BACKGROUND

From 30 years onwards there is a linear reduction of renal function of about 0.41% per year. Aging induces progressive impairment of glomeruli leading to an increase in protein excretion. The purpose of the present study was to investigate the effect of maximal exercise on glomerular filtration rate (GFR) and albumin excretion in an aging population.

METHODS

This is a cross-sectional study from 213 healthy men, sedentary or endurance-trained, aged 20-30 and 50-80 years submitted to maximal exercise on a cycle ergometer. Blood and urine samples were obtained at rest and after the strenuous exercise. We evaluated the GFR by measuring creatinine clearance and the urine albumin excretion rate.

RESULTS

After exercise, the older adults had a lesser reduction in GFR (mean 12%) than the young participants (mean 28%). As compared to those at rest, the increase of postexercise albumin excretion rates was lower in older participants (mean 7-fold) versus the young population (mean 20-fold). It appears that the exercise impact on some renal functions is related to the absolute load imposed on the individuals (r2 = 0.693).

CONCLUSION

As far as GFR and urine albumin excretion are concerned, regular endurance training does not induce any signs of potential incipient nephropathy in a healthy aging population.