Wednesday, May 25, 2011
TOPIC DISCUSSION: Origins of the 1.73m2 in the GFR formula?
Basically, the simple answer is "arbitary". The 1.73 refers to the standardized body surface area(BSA) used to normalize for all variables for an average 70kg man. Interestingly, this one paper that I reference below taunts the idea of this in a very comical way and shows where this originally came from. Apparently in 1928, on a basis of just 8 children and 7 adults, the authors found a constant value can be substituted and they said it was 1.73m2- which was the mean of the areas of men and women age 25 from prior medical and acturial tables. So this was based on actuarial data showing the BSA using Dubose formula and then subtracting 1 inch from height in shoes and 5 pounds from weight in clothes and different variables for children and women. Basically,this was based on american clothing standards and weights in 1920s.
Nothing has changed in using that number in last 80+ years. The authors of the paper referenced below show that compared to 1920s, current average male weight is 80kg and hence the BSA should be technically corrected by 1.92m2 and not 1.73m2.
Even if they chose less obese European population, it came to 1.86m2. Interesting, if we did that, there would be an immediate 9% increase in world GFR per the authors. In general, to get a BSA measurement in the over weight and obese population is a tough task and not easy to measure- for us making GFR a harder thing to measure then as well as almost all measurements of GFR including MDRD correct for BSA and use 1.73m2.
"Is it a time to change or is 1.73m2 going to live longer than all of us like it has been!!"
image source: wikipedia.com
- ► 2018 (55)
- ► 2017 (52)
- ► 2016 (45)
- ► 2015 (63)
- ► 2014 (95)
- ► 2013 (133)
- ► 2012 (201)
- TOPIC DISCUSSION: The return of "Spironolactone"
- Match the drugs with the toxicity game!
- CLINICAL CASE and ANSWERS 38
- TOPIC DISCUSSION: Clinical Pearls for electrolytes...
- TOPIC DISCUSSION: Origins of the 1.73m2 in the GFR...
- Prolia or Xgeva, Denosumab and The Renal world!
- Alemtuzumab for Induction- the 2011 update
- TOPIC DISCUSSION: Hibernating Bear's urine?
- CONSULT ROUNDS: Ethylene Glycol Toxicity
- Asian Dialysis Modality Survey by Pediatric Nephro...
- Check out this website
- Tumor Lysis Syndrome
- Medicine for residents: Elevated pulse pressure an...
- TOPIC DISCUSSION: Micro Rnas and Chronic Kidney Di...
- Nephrology Crosswords- Pediatric Nephrology
- NKF 2011 Recap- Rhabdomyolysis as the theme
- Donor Risk Scores?
- CLINICAL CASE 37, ANSWERS AND SUMMARY
- "Brain Drain" in nephrology
- TOPIC DISCUSSION: The Distal Hypoperfusion Ischemi...
- Nephrology Fellow Career Choice Satisfaction Surve...
- Dual Live Transplants performed
- Interesting Urine Lytes
- NKF 2011 Live: First Clinical Guidelines on Acute ...
- CLINICAL CASE 36, ANSWERS AND SUMMARY
- IN THE NEWS- Hyponatremia and Mortality( its the u...
- ▼ May (26)
- ► 2010 (461)