For today’s #ScienceSunday, I am going to have to discuss a murky subject brought on by the recent telomere results of my patients which arguably showed massive improvements in telomere length without commensurate increases in biological age. Here is the email I received:
“Elane and I reviewed the latest test data and she shared the discussion you and she had. What’s still not clear is the different scale that Life Length is using in 2014 vs the one used in 2013. Specifically, my median telomere length in 2013 was 7.64 against a normal range of 5.9 to 8.9 In 2014 the median length is 11.6, a significant increase but now is measured against a normal scale in 2014 of 8.5 to 13.7. Elane has a similar increase in median length, but against the new scale shows a “decline” compared to the normal range. Please help us understand the scale change. Also, since the number of short telomeres appears to be an item to watch, the 2013 report shows a percentage, for me at 13.6%. The 2014 report shows the 20th percentile to be 6.4kb. How does one get a relative comparison between the 2013 and 2014 tests?”
And this was my reply. Honest yet as encouraging as a barrel ride over Niagara Falls. (It should be noted that they both feel amazing and are convinced they are getting younger.)
You are absolutely correct and incisive in your analysis. As I attempted to sheepishly convey to Elaine, the current situation a bit like the Tower of Babel when it comes to telomere measurements.
Because of poor information sharing, esoteric and ill-defined criteria, and wildly disparate methodologies, the truth is that there is very little agreement in this field. When median telomere lengths of the same sample can be reported as 4k, 7k, and 11k, you have to wonder when these labs will get together and standardize what they are able to measure.
This is not to say that the testing is not repeatable. My considerable experience with the Repeat diagnostics test (FlowFSH out of Canada) and the LifeLength test (FlowFSH from Spain) has suggested that at least within current iterations of their tests, the results are highly repeatable and precise with very little margin of error.
So why did I have you do the testing?
Because…within an individual, over time, while attempting to understand an intervention like telomerase activation, and while using the same methodology, the results can be quite useful! (Although the interpretation is, for want of a better expression, open to interpretation.)I hope that this explanation helps, but I strongly suspect that it does not. Perhaps if you haven’t already read my book, “Telomere Timebombs: Defusing the terror of aging”, then you might benefit from the explanation I give about telomere measurements. If you would like to read a few musings about the topic, please refer to this blog posting that I did on the subject: http://wp.me/p3ZZaP-13Z Thank you and congratulations on getting 40 years “younger” (all caveats aside).Very best regards,
Ed Park, MD, MPH
I suppose the bottom line is “GIGO” (garbage in, garbage out). We need to have better quantification of genome-wide as well as telomere-specific variation, a way to assess clonality, and a way to sample more than just the easy-to-draw leukocytes. Because the academics are not interested in asking asking the fundamental questions (they have largely surrendered to the false idea that leukocyte telomere length is a proxy for “biological age”), we should continue supporting commercial labs which will be able to lower the cost of testing as they become financially more viable. To learn more about this fascinating topic, watch this video podcast: