Few chronic kidney disease patients at risk from end-stage disease

The results of research led by academics at The University of Nottingham will be a cause for optimism among patients suffering from chronic kidney disease (CKD).

The five-year study, published this week in PLOS Medicine, revealed that the vast majority of CKD sufferers have a benign disease with little risk of progression and complications.

The research, which followed the fortunes of 1,700 patients, was led by Dr Adam Shardlow and colleagues in the University's School of Medicine based at the Royal Derby Hospital.

Dr Shardlow said: "These results will help clinicians explain the likely outcomes of chronic kidney disease to patients diagnosed with CKD in the community. In contrast to common ideas about CKD, we have shown the majority people in our cohort were stable over the five-year follow-up period, with a significant minority demonstrating improvement.

"Those with a high risk of progression can be identified using simple measures and referred early to specialist services."

Severe cases

CKD affects 10 to 20 per cent of adults in most countries and can progress to end-stage kidney disease, requiring dialysis or kidney transplantation. Previous studies on the progression of the disease have been conducted in large teaching hospitals by kidney specialists, where the most complicated and severe cases are generally referred, despite the fact that most CKD patients have a mild disease and are seen only by primary care doctors.

To understand the course of disease in the larger patient population seen by primary care, Dr Shardlow and colleagues recruited 1,741 patients with stage 3 CKD – a mild form of the disease – from 32 primary care practices in Derbyshire. They used the standard Kidney Disease Improving Global Outcomes (KDIGO) criteria to gauge the status of each person's disease at baseline, one year later, and five years later.

After five years, 247 patients (14.2 per cent) had died, mostly of cardiovascular causes; four patients (0.2 per cent) had progressed to end-stage; 308 others (17.7 per cent) had progressed to a lesser extent; 593 (34.1 per cent) still had stable, stage 3 CKD; and 336 (19.3 per cent) met the criteria for complete remission of CKD.

The results also indicated that a handful of factors – included estimated glomerular filtration rate and albuminuria – were associated with CKD progression or remission. The statistics on how patients progress may not be applicable to all populations since the study population was predominantly elderly and white. But in light of the new analysis, 'management of CKD in primary care should focus principally on identifying the minority of people at high risk of adverse outcomes,' the authors say.

Reassuring results

Chief Investigator Professor Maarten Taal added: "Our study will be very reassuring for people with chronic kidney disease because most worry that they will need dialysis but out results show that only a very small minority ever reach this stage.

"This study illustrates the value of well-designed prospective observational studies. Randomised trials are the best method for testing the efficacy of new treatments but high quality observational studies are essential to improve our knowledge of the natural history and pathogenesis of diseases."

In an accompanying editorial, Guiseppe Remuzzi and Richard Glassock discuss the evolution of classification and diagnosis of CKD and the challenges of pinpointing surveillance factors that can predict which patients are at risk of their CKD progressing. The new study, they say, 'identifies factors, easily obtained and possibly modifiable, that should heighten surveillance for the minority of subjects with CSK Stage 3 who are at risk for progression.'

The article can be accessed via the PLOS Medicine website.