This is incredibly helpful, thank you! As an endurance athlete I see a lot of my fellow athlete friends stress over their A1C readings. Mine personally tend to be a bit higher but my insulin is extremely low. I haven't done a CGM because I think that would lead me down a terrible rabbit hole (that I've seen other athletes go through). Appreciate this info!
Hi Dr, you reference blood test readings here. Can you say (or point me at) something which indicates how our reference ranges are determined? I see comparisons of serum tests against good and bad levels, so much of primary care is nowadays built on these but the mystery is are these ranges linear, exponential, cognizant of age or body size, are they (example) +/- 1xSD from median? Where are the data from? Typically only poorly people get tested, intuitively this surely skews the figures.
Hi Gary. I know this question wasn’t for me. But my natural curiosity about your excellent question led me down a small rabbit hole. I found a fascinating discussion of the issues with reference ranges here:
Thanks. Interesting, and disappointing, but not surprising. Key quote "different labs may use very different reference ranges for no good reason; or there may be a good reason, but the users of the service may not know."
In a world where metrology is understood and most measurements in the UK/EU are accredited ( in the UK by UKAS) this is bananas.
There is very little of what might be called a 'chain of trust' here.
Super interesting post and I am interested to learn more about the link between animal protein/fat and glucose. I was vegan for 3 years and had the lowest lipid and blood sugar. The changed to normal whole food diet with tons of vegetables and whole grains with occasional eggs fish and chicken. Lipid still great except LDL 111, but BS went up to close to 100 fasting and ha1bc steadily increased to 5.6. Endurance runner, 40-60 miles a week of running with 2-3 resistant training. Any insight on the link between LDL, BS, vegan/animal protein, would be appreciated.
This and your Pre-diabetes in Athletes were OUTSTANDING. I have dealt with FBG 98-107 for years with A1C since 2012 5.1-5.9 (fasting insulin .9-2.5 typical, normal OGTT, normal Kraft Test). Diet is very low fat because I found if I eat much animal products the glucose will creep up to 120 and the A1C to 6.2 so I am virtually vegan for a decade (liver insulin resistance due to sat. fat probably). I do cardio and resistance 7 days a week usually and used to race 2-3 IM events for 10 years and maintain very low body fat secondary to lifestyle. At 61 have worried about this for years and it is so good to see that this may simply be more of a "physiologic aberrancy" related to training. Any further insights, caveats, etc on this topic are appreciated. I would encourage you to right and research more on this as I think there are many athletes who are doing their level best and are probably getting themselves into issues like RED-S (relative energy deficiency in sport) with the hormonal, reproductive, skeletal complications by trying to correct what may be a normal physiologic adaptation. This would be a seriously valuable research project ie to confirm or refute physiologic sequelae from this fasting only mild glucose elevation.
Unrealted to this topic, my wife is T2D, and everytime she supplements with any kind of liquid fat, her LDL, TG, & H1C goes up. First she tried supplementing with 1 tbsp per day of olive oil and it worsened those 3 markers, so she stopped, and those 3 markers went back down.
Now she's supplementing with 2.5 grams of fish oil per day, and same thing! All 3 markers went up again! What the heck? Now she has to stop taking fish oil. Anyone knows what's going on?
How healthy is it to elevate stress hormones via exercising? Does life-long exercise-induced stress-hormone elevation lead to longer lifespan, or does it shorten lifespan?
This is incredibly helpful, thank you! As an endurance athlete I see a lot of my fellow athlete friends stress over their A1C readings. Mine personally tend to be a bit higher but my insulin is extremely low. I haven't done a CGM because I think that would lead me down a terrible rabbit hole (that I've seen other athletes go through). Appreciate this info!
Hi Dr, you reference blood test readings here. Can you say (or point me at) something which indicates how our reference ranges are determined? I see comparisons of serum tests against good and bad levels, so much of primary care is nowadays built on these but the mystery is are these ranges linear, exponential, cognizant of age or body size, are they (example) +/- 1xSD from median? Where are the data from? Typically only poorly people get tested, intuitively this surely skews the figures.
Hi Gary. I know this question wasn’t for me. But my natural curiosity about your excellent question led me down a small rabbit hole. I found a fascinating discussion of the issues with reference ranges here:
https://www.bennett.ox.ac.uk/blog/series/openpathology-issues-with-reference-ranges/
Thanks for asking this question because I think it’s information that the general population should be aware of.
Thx Micheila, I'll take a long look at that link :-)
Thanks. Interesting, and disappointing, but not surprising. Key quote "different labs may use very different reference ranges for no good reason; or there may be a good reason, but the users of the service may not know."
In a world where metrology is understood and most measurements in the UK/EU are accredited ( in the UK by UKAS) this is bananas.
There is very little of what might be called a 'chain of trust' here.
Super interesting post and I am interested to learn more about the link between animal protein/fat and glucose. I was vegan for 3 years and had the lowest lipid and blood sugar. The changed to normal whole food diet with tons of vegetables and whole grains with occasional eggs fish and chicken. Lipid still great except LDL 111, but BS went up to close to 100 fasting and ha1bc steadily increased to 5.6. Endurance runner, 40-60 miles a week of running with 2-3 resistant training. Any insight on the link between LDL, BS, vegan/animal protein, would be appreciated.
This and your Pre-diabetes in Athletes were OUTSTANDING. I have dealt with FBG 98-107 for years with A1C since 2012 5.1-5.9 (fasting insulin .9-2.5 typical, normal OGTT, normal Kraft Test). Diet is very low fat because I found if I eat much animal products the glucose will creep up to 120 and the A1C to 6.2 so I am virtually vegan for a decade (liver insulin resistance due to sat. fat probably). I do cardio and resistance 7 days a week usually and used to race 2-3 IM events for 10 years and maintain very low body fat secondary to lifestyle. At 61 have worried about this for years and it is so good to see that this may simply be more of a "physiologic aberrancy" related to training. Any further insights, caveats, etc on this topic are appreciated. I would encourage you to right and research more on this as I think there are many athletes who are doing their level best and are probably getting themselves into issues like RED-S (relative energy deficiency in sport) with the hormonal, reproductive, skeletal complications by trying to correct what may be a normal physiologic adaptation. This would be a seriously valuable research project ie to confirm or refute physiologic sequelae from this fasting only mild glucose elevation.
Unrealted to this topic, my wife is T2D, and everytime she supplements with any kind of liquid fat, her LDL, TG, & H1C goes up. First she tried supplementing with 1 tbsp per day of olive oil and it worsened those 3 markers, so she stopped, and those 3 markers went back down.
Now she's supplementing with 2.5 grams of fish oil per day, and same thing! All 3 markers went up again! What the heck? Now she has to stop taking fish oil. Anyone knows what's going on?
How healthy is it to elevate stress hormones via exercising? Does life-long exercise-induced stress-hormone elevation lead to longer lifespan, or does it shorten lifespan?
My pleasure. I learned something new!
You are THE BOMB DOC!!!!