We recommend that all people with chronic anaemia associated with chronic kidney disease should be investigated for the cause and possible treatment, irrespective of the grade of kidney disease or requirement for kidney replacement therapy if:
- Their haemoglobin (Hb) levels are less than 110 g/L (less than 105 g/L if younger than 2 years), or they develop symptoms attributable to anaemia. This is to ensure the correct diagnosis and management of anaemia. (1A)
The UK Kidney Association (UKKA) and Royal College of Physicians endorse the NICE Guidelines for Chronic Kidney Disease: Managing Anaemia (1). The reader is referred to these guidelines as well as the European Renal Best Practice (ERBP) for Anaemia in CKD (2,3) and the KDOQI (4) Guidelines for management of anaemia in CKD. The KDIGO website (www.kdigo.org) (5) is a useful site of reference for comparison of evidence-based guidelines internationally.
Anaemia is defined as having a Hb value below the established cut off defined by the World Health Organisation (4). Different defined groups have different cut offs. For adults:
- Men and postmenopausal women Hb <130 g/L
- Premenopausal women Hb <120 g/L
- Pregnant women Hb <110 g/L
Rationale
In 2006, KDOQI modified this definition by giving a single criterion for diagnosing anaemia in adult males (Hb <135 g/L, regardless of age) because the decrease in Hb among males aged >60 years is often attributable to associated co-morbidities (4), while KDIGO suggest a diagnosis of anaemia in adults with CKD when the Hb concentration is <130 g/L in males and <120 g/L in females (5).
Anaemia is defined as a haemoglobin concentration less than the 5th percentile for age. Hb levels vary by age, and many laboratories use adult norms as references; therefore, the patient’s Hb level must be compared with age-based norms to diagnose anaemia (6).
In addition to sex, age and pregnancy other factors influence Hb level including smoking, altitude, race and genetic disorders (thalassemia and sickle cell disease). In CKD, a person‘s anaemia should be defined using these same criteria. The degree of kidney impairment affects the likelihood of any person developing anaemia. Although current treatment with ESAs is not recommended unless Hb falls consistently below 110 g/L, other causes of anaemia should be excluded in persons with Hb below normal range. The current definition for anaemia applies to adult subjects older than 18 years, of all races and ethnic groups, and living at relatively low altitude (<1,000 m or 3,000 ft.) (7). With increasing altitude, endogenous erythropoietin production is increased; as a result, Hb concentration can be expected to increase by about 6 g/L in women and 9 g/L in men for each 1,000 m of altitude above sea level (8).
References
- National Collaborating Centre for Chronic Conditions, Royal College of Physicians. Guideline on anaemia management in chronic kidney disease. 2015. National Institute for Clinical Health and Excellence. Available on http://www.nice.org.uk/guidance/NG8/evidence (accessed 15/06/2017).
Locatelli F, Aljama P, Barany P et al. Revised European Best Practice Guidelines for the management of anaemia in patients with chronic renal failure. Nephrol. Dial. Transplant. 2004; 19 Suppl 2: ii1-47.3.
Locatelli F, Bárány P, Covic A, et al. Kidney Disease: Improving Global Outcomes guidelines on anaemia management in chronic kidney disease: a European Renal Best Practice position statement. Nephrol Dial Transplant. 2013 Jun;28(6):1346-59.
KDOQI; National Kidney Foundation Clinical practice guidelines and clinical practice recommendations for anaemia in chronic kidney disease in adults. Am J Kidney Dis. 2006 May; 47(5 Suppl 3):S16-85.
KDIGO Clinical Practice Guideline for Anaemia in Chronic Kidney Disease. Kidney Int Suppl 2012;2:279-335.
Oski FA, Brugnara C, Nathan DG. A diagnostic approach to the anaemic patient. In: Nathan and Oski’s Haematology of Infancy and Childhood. 6th ed. Philadelphia, Pa.: Saunders; 2003:409–418
World Health Organisation. Iron deficiency anaemia, assessment, prevention and control: a guide for programme managers. 2001.
Beall CM, Goldstein MC. Haemoglobin concentration of pastoral nomads permanently resident at 4,850-5,450 meters in Tibet. Am J Phys Anthropol 1987; 73:433-438.