Physical activity and kidney function in health and disease
Roy J. Shephard in Physical Activity and the Abdominal Viscera, 2017
This chapter examines the impact of physical activity upon the normal functioning of the kidneys, and explores such manifestations of temporary dysfunction as exercise-induced microproteinuria and microhaematuria. It considers the potential of developing acute renal failure during a prolonged bout of exhausting exercise and the possibility of chronic renal damage in athletes with an excessive intake of creatine supplements or non-steroidal anti-inflammatory drugs (NSAIDs). The chapter examines the place of exercise programmes in the rehabilitation of patients who are undergoing dialysis or who have received renal transplants, and it considers the possibility that regular physical activity may reduce the risk of renal cancer. A large intake of anti-inflammatory drugs can also have adverse effects on the kidney, particularly in individuals whose bodies normally rely on an increased prostaglandin secretion to counter a reduced renal blood flow. In humans, vigorous physical activity leads to a progressive drop in the glomerular filtration rate (GFR) as renal perfusion decreases.
Acute kidney injury
Sherif Gonem, Ian Pavord in Diagnosis in Acute Medicine, 2017
Acute kidney injury (AKI) is diagnosed on the basis of an acute rise in serum creatinine concentration, a fall in glomerular filtration rate or a fall in urine output. AKI may be caused by a drop in renal perfusion obstruction to urine outflow at any point from the ureters to the urethral outlet or intrinsic disease of the kidneys. Intrinsic renal disease may be further sub-divided into vascular disease, glomerular disease, acute interstitial nephritis and acute tubular necrosis. Thus the mechanisms of acute kidney injury may be summarised as follows; pre-renal; post-renal; renal. Initial management focuses on the detection and treatment of life-threatening complications of acute kidney injury, and correction of easily reversible causes of renal dysfunction, such as hypovolaemia and urinary tract obstruction. Perform a full systemic enquiry, as multi-system disease may present with acute kidney injury. Hyperphosphataemia is a common feature of acute kidney injury.
Clinical biochemistry at the extremes of age
Martin Andrew Crook in Clinical Biochemistry & Metabolic Medicine, 2013
This chapter looks at clinical biochemistry at the extremes of age, that is, in neonates and the elderly. The most significant advances in medical care has been the survival rate of very small preterm infants, which has increased because of improved specialized medical and nursing techniques for treating the neonate. The chapter examines these infants can experience a number of abnormal biochemical conditions. Diseases occurring during the neonatal period can be divided into two main groups: those of infants born before term, in whom immaturity contributes to the severity of the disease, and those of full-term infants. The plasma urea concentration is low in newborn infants compared with that in adults, despite the relatively low glomerular filtration rate; the high anabolic rate results in more nitrogen being incorporated into protein rather than into urea than in adults. Renal function in newborn infants can maintain basic homeostasis but may not be able to respond adequately to illness or other stresses.
A Comparison of Prediction Equations for Estimating Glomerular Filtration Rate in Pregnancy
Published in Hypertension in Pregnancy, 2009
Sofia B. Ahmed, Rhonda Bentley-Lewis, Norman K. Hollenberg, Steven W. Graves, Ellen W. Seely
Objective: To compare existing glomerular filtration rate (GFR) prediction equations with the gold standard, inulin clearance, in pregnancy. Methods: Five equations were assessed for precision, bias, and accuracy in prediction of true GFR, measured by inulin clearance in 12 healthy, pregnant women during the second (T2) and third (T3) trimesters and in postpartum (PP). Results: Precision was greatest with 24-hour creatinine clearance estimation of GFR (R2 = 13% (T2), R2 = 26% (T3)). Other than 100/SCr, all equations underestimated true GFR. 30% accuracy was greatest in 100/SCr (83% (T2), 92% (T3)). Conclusions: Current GFR prediction formulae do not appear to be sufficient for estimating GFR in the gravid state.
Correlation of Cystatin-C with Glomerular Filtration Rate by Inulin Clearance in Pregnancy
Published in Hypertension in Pregnancy, 2012
A. R. Saxena, S. Ananth Karumanchi, S.-L. Fan, G. L. Horowitz, N. K. Hollenberg, S. W. Graves, E. W. Seely
Objective. To test utility of cystatin-C as a marker of glomerular filtration rate during pregnancy, we performed serial correlations with inulin clearance during pregnancy and postpartum. Methods. Twelve subjects received inulin infusions and serum cystatin-C at three time points. Pearson's correlation coefficient was calculated. Results. Cystatin-C levels ranged 0.66–1.48 mg/L during pregnancy, and 0.72–1.26 mg/L postpartum. Inulin clearance ranged 130–188 mL/min during pregnancy, and 110–167 mL/min postpartum. Cystatin-C did not correlate with inulin clearance at any time point. Conclusion. Serum cystatin-C did not correlate with inulin clearance during pregnancy or postpartum.
Obesity in kidney transplant recipients: association with decline in glomerular filtration rate
Published in Renal Failure, 2013
Thaís Rodrigues Moreira, Tayron Bassani, Gizele de Souza, Roberto Ceratti Manfro, Luiz Felipe Santos Gonçalves
In this study we aimed to evaluate the influence of obesity in kidney and patient survival and graft function. Retrospective cohort study of kidney transplant recipients performed between 2001 and 2009. The body mass index was calculated at time of transplantation, one and five years after. The main outcomes studied were incidence of delayed graft function, new onset diabetes after transplantation, patient and graft survival, and glomerular filtration rate. The prevalence of obesity and overweight patients were 10.7% and 26.8% respectively, with an increase to 16.9% and 32.5% one year after transplantation. Underweight and obese recipients presented a higher incidence of early graft loss. The incidence of new onset diabetes after transplantation was significantly higher at one and five years in overweight or obese recipients at baseline. Overweight and obese recipients presented significantly lower estimated glomerular filtration rate at five years posttransplantation (p = 0.002). In the Kaplan–Meier analyses no statistically significant differences in patients or grafts survivals were observed. Obese patients have a higher rate of early graft failure and a higher new onset diabetes after transplantation incidence. Also, the finding of decreased glomerular filtration rate is worrisome and perhaps longer follow-up will reveal more graft failures and patients deaths in the group of obese recipients.
Related Knowledge Centers
- Inulin
- Urinary Tract
- Kidney
- Kidney Function Tests
- Urinary Tract Physiological Phenomena
- Nephrology
- Renal Physiology