Definition

Chronic kidney disease (CKD) can be defined as abnormalities in kidney function or structure (or both), sustained for more than 3 months. This may include a reduction in glomerular filtration rate (GFR), urinary abnormalities such as proteinuria, or structural abnormalities of the renal tract.

Epidemiology and impact

The estimated global prevalence of CKD is 9.1%, with an estimated 10-11% of individuals now affected in the UK. It is more common in females, but progresses to end stage kidney disease more frequently in males. Prevalence increases with age. CKD is also more common in individuals from Black or Asian backgrounds.

CKD and health inequalities

Two of the leading causes of CKD in the UK, diabetes and hypertension, are frequently driven by social determinants of health including economic status, where people live, healthcare access, and level of education. Studies have shown disproportionate rates of CKD in socially deprived populations, and these groups are also less likely to be listed for kidney transplantation. Patients from ethnic minority backgrounds are more likely to have CKD, progress to end stage kidney disease at a younger age, and are less likely to receive a kidney transplant. Rates of transplantation are lowest for those of Black ethnicity.

Outcomes for those with CKD

Approximately 2% of individuals with CKD progress to end stage kidney disease requiring kidney replacement therapy. Most morbidity and mortality in individuals with CKD results from a significantly increased risk of cardiovascular events compared to those without CKD. This increased risk is inversely proportional to eGFR, with later stages of CKD associated with greater risk of ischaemic heart disease, stroke, and heart failure. Higher levels of albuminuria also convey increased risk of adverse cardiovascular events.

CKD is often referred to as ‘silent’, however many individuals have a significant burden of symptoms particularly at later stages of disease. Whilst there is not a clear symptom complex in CKD in the same way as some other long-term conditions, fatigue, pain, breathlessness, and itch are commonly seen. There is also a high prevalence of associated psychological health problems.