Ever noticed that thing called RDW (red cell distribution width) reported in your patients’ haematology results? Given that this parameter is currently regarded as one of the most important & earliest markers of a wide range of serious diseases, you might start paying some more attention to it from now on!

Dr. Michael Hayter, cleverly refers to RDW as being a reflection of the ‘Quality Control’ of an individual’s red blood cell synthesis.

As it’s a measure of how similar or dissimilar our rbcs are in terms of size, smaller values (suggesting homogeneous rbcs) are regarded as healthy, while higher RDWs suggest that some part of  rbc synthesis and/or clearance process is faulty.

This makes perfect sense in the context of nutritional anaemias like iron and B12/folate which all produce elevated RDW results but new research proposes that this rbc size disparity is also a common linking feature in just about every major disease, often predating diagnosis or in cases of established pathology signalling progression and warning of imminent poor outcomes for the individual.

There have been 100s of papers published just in the past 4 years on this topic and the findings are nothing if not dramatic. One of the biggest things I’ve realised is that, while Australian pathology companies suggest that all RDW results < 16% are acceptable, in the light of these new associations, a more accurate cut-off is probably around 13.5%! The big question now to answer is, is the increased RDW a passive marker of pathology or actively involved in the pathogenesis of these major diseases. For now, we should be scrutinising our patients’ RDW results more closely and being alert to what these markers are telling us about our clients threats & risks. I’ve recorded a 30min audio summarising all the information I’ve come across on this topic and how to apply it in your patients which you can access here.

Alternatively, if you’re happy to chomp into some juicy journal articles yourself then check out these ones to start with

https://jaha.ahajournals.org/content/3/4/e001109.full

https://www.researchgate.net/profile/Fabian_Sanchis-Gomar/publication/269930590_Red_blood_cell_distribution_width_A_simple_parameter_with_multiple_clinical_applications/links/5499b0e50cf2d6581ab15143.pdf