I often say that if my surname was Rubin I wouldn’t be able to resist calling my son Billy. I am sure the joke would be lost on 90% of people & certainly on my poor child who might never forgive me but never on me – I get a giggle every time 🙂  Recently, I’ve been reading a lot of scientific literature on bilirubin, previously regarded as simply the end waste product of haem, it’s now attracting huge interest as a biomarker of oxidative stress.  There’s still lots of ongoing debate & contradictory research findings but here’s the general consensus so far…bilirubin is an antioxidant (particularly protective against peroxyl radicals & lipid oxidation although the latter is still being hotly debated).  Not surprisingly then, several studies have shown that smokers for example, consistently have lower total bilirubin blood values, indicative of their greater oxidative stress & yes, smoking cessation leads to partial correction of this (O’Malley et al. 2014 Smoking Cessation Is Followed by Increases in Serum Bilirubin, an Endogenous Antioxidant Associated With Lower Risk of Lung Cancer and Cardiovascular Disease)  A recent study also found a positive correlation between higher flavonoid rich fruit & vegetable intake and total bilirubin (Laprinzi & Mahoney 2014 Association Between Flavonoid-Rich Fruit and Vegetable Consumption and Total Serum Bilirubin).

On top of this, there is a wave of epidemiological research to currently surf, suggesting inverse relationships between total bilirubin levels and several diseases: hypertension & CVD, T2DM, metabolic syndrome, MS, renal disease, IBD, lung cancer and the list goes on.  The sort of cut-off point being talked about is a result < 10 µmol/L being associated with the highest risk.  What remains unclear is whether lower bilirubin levels are actually risk-promoting or whether they are just a signal of the individual’s oxidative stress.

Total bilirubin (aka Indirect or Unconjugated bilirubin) values are typically included in most pathology company’s basic general chemistry or E/LFT panels which means most of your patients already have had this test performed in the previous 12 months.  So next time you’re looking at patient results check out their bilirubin values and if they have bilirubin levels consistently <10µmol/Lconsider how you might better support your patient manage their oxidative burden to reduce risk of future disease and if you’re hitting the mark the bilirubin level should rise 🙂

Want to know more about Bilirubin and Pathology interpretation in general – Rachel is collaborating with Dr. Michael Hayter to present an online Master Class in Diagnostics starting this week.  For more information check out Health Masters Live https://www.healthmasterslive.com/product/clinical-diagnostics-masterclass/?mc_cid=cfd82dd367&mc_eid=014c831228