Special Interest: Renal medicine

Nephrotic syndrome is uncommon in general practice. A GP may only see two or three adult cases in their career. Nephrotic syndrome develops following pathological injury to renal glomeruli. This may be a primary problem, with a disease specific to the kidneys, or secondary to a systemic disorder such as diabetes mellitus. The most common cause in children is minimal change glomerulonephritis. In white adults, nephrotic syndrome is most frequently due to membranous nephropathy whereas in populations of African ancestry the most common cause of nephrotic syndrome is focal segmental glomerulosclerosis (FSGS). Diabetic nephropathy is the most common multisystem disease that can cause nephrotic syndrome. 

The incidence of renal stone disease is increasing globally. In the UK the lifetime risk is estimated to be 8-10%. On a population level, the increase in stone incidence, erosion of gender disparity, and younger age of onset is likely to reflect increasing prevalence of obesity and a Western diet with a high intake of animal protein and salt.

Glomerulonephritis is an important cause of kidney disease and, in the UK, the most common diagnosis in patients receiving chronic dialysis or waiting for kidney transplantation. A key feature is the presence of urinary abnormalities (proteinuria ± haematuria). Timely diagnosis and treatment of glomerulonephritis can help to minimise both the occurrence and severity of complications.

End-stage renal disease describes loss of kidney function which is both substantial and irreversible. The form of renal replacement therapy (RRT) instituted should primarily be based on patient preference subsequent to an individually tailored education programme from specialist staff. This programme needs to take into account the patient’s comorbidities and any contraindications to specific modalities of RRT. For those who will be suitable for transplantation, optimum management of diabetes, smoking cessation, weight loss, and general fitness is crucial in facilitating this.

CKD affects 8.5% of the UK population. Early recognition allows intervention that may delay or avoid progression to end-stage disease and modify the cardiovascular risk associated with CKD. The most frequent specific renal diseases resulting in progressive CKD in the UK are: diabetes mellitus, atheromatous renal vascular disease, glomerulonephritis, chronic pyelonephritis and inherited renal disease.

About 20% of all adult emergency admissions are affected by acute kidney injury (AKI) and the mortality rate is almost 25%.  It has been estimated that AKI, excluding cases in the community, causes more than 10,000 preventable deaths a year in England. AKI represents a wide spectrum of injury to the kidneys, not just kidney failure, the vast majority of AKI cases start with an illness in the community. In AKI, loss of kidney function contributes to morbidity and mortality. Patients die from AKI rather than with AKI as a complication of an underlying illness. The definition of AKI now includes any adult with ≥ 26 µmol/L rise in creatinine from baseline over 48 hours or less, or  ≥ 50% rise in creatinine from baseline known or presumed to have occurred over seven days or less.