What blood tests have reference ranges that depend on age?

DragonBits

Well-Known Member
We know some reference ranges on blood test are adjusted for age, but I don’t know which ones are and which aren’t. This is important because it tells us if we are over or under range, creates flags on blood tests, may concern patients or doctors.



Recently Dr. X contributed the fact that Free T range is age adjusted, which I did not know.



Here are some blood tests I know are age adjusted, some I don’t know.



I see IGF-1 has a reference range which I got from a Mayo Med lab site, I don’t know what range Labcorp uses, on my most recent blood test for IGF-1 the range they used was 47-192 and I was 66,but the blood test 6 months earlier the range was 49-188 ng/mL, I was 65. The range changed, not exactly in a way I would expect.



18-22 years: 91-442 ng/mL
23-25 years: 66-346 ng/mL
26-30 years: 60-329 ng/mL
31-35 years: 54-310 ng/mL
36-40 years: 48-292 ng/mL
41-45 years: 44-275 ng/mL
46-50 years: 40-259 ng/mL
51-55 years: 37-245 ng/mL
56-60 years: 34-232 ng/mL
61-65 years: 33-220 ng/mL
66-70 years: 32-209 ng/mL
71-75 years: 32-200 ng/mL
76-80 years: 33-192 ng/mL
81-85 years: 33-185 ng/mL
86-90 years: 33-179 ng/mL
91 years: 32-173 ng/mL

Dr Justin Saya MD recently contributed that the Free T test also has an age adjusted range.


It seems Jay who is younger than me has a range for free T of 6.8-21.5
I have a range of 6.6-18.1 when I was 66, but the range when I was 60 was 5-21. This is all from labcorp.


Labcorp DHEA reference range.

Age Male Female
20 to 24 y 164.3−530.5 110.0−431.7
25 to 34 y 138.5−475.2 84.8−378.0
35 to 44 y 102.6−416.3 57.3−279.2
45 to 54 y 71.6−375.4 41.2−243.7
55 to 64 y 48.9−344.2 29.4−220.5
65 to 74 y 30.9−295.6 20.4−186.6
≥75 y 20.8−226.4 13.9−142.8




004020: Dehydroepiandrosterone (DHEA) Sulfate | LabCorp



So far, IGF-1, Free T and Dhea all have ranges that change with age. PSA has a suggested age adjustment, but labs don’s seem to use it.


Do people know if these are the only blood tests where the range depends on age?
 
We know some reference ranges on blood test are adjusted for age, but I don’t know which ones are and which aren’t. This is important because it tells us if we are over or under range, creates flags on blood tests, may concern patients or doctors.



Recently Dr. X contributed the fact that Free T range is age adjusted, which I did not know.



Here are some blood tests I know are age adjusted, some I don’t know.



I see IGF-1 has a reference range which I got from a Mayo Med lab site, I don’t know what range Labcorp uses, on my most recent blood test for IGF-1 the range they used was 47-192 and I was 66,but the blood test 6 months earlier the range was 49-188 ng/mL, I was 65. The range changed, not exactly in a way I would expect.



18-22 years: 91-442 ng/mL
23-25 years: 66-346 ng/mL
26-30 years: 60-329 ng/mL
31-35 years: 54-310 ng/mL
36-40 years: 48-292 ng/mL
41-45 years: 44-275 ng/mL
46-50 years: 40-259 ng/mL
51-55 years: 37-245 ng/mL
56-60 years: 34-232 ng/mL
61-65 years: 33-220 ng/mL
66-70 years: 32-209 ng/mL
71-75 years: 32-200 ng/mL
76-80 years: 33-192 ng/mL
81-85 years: 33-185 ng/mL
86-90 years: 33-179 ng/mL
91 years: 32-173 ng/mL

Dr Justin Saya MD recently contributed that the Free T test also has an age adjusted range.


It seems Jay who is younger than me has a range for free T of 6.8-21.5
I have a range of 6.6-18.1 when I was 66, but the range when I was 60 was 5-21. This is all from labcorp.


Labcorp DHEA reference range.

Age Male Female
20 to 24 y 164.3−530.5 110.0−431.7
25 to 34 y 138.5−475.2 84.8−378.0
35 to 44 y 102.6−416.3 57.3−279.2
45 to 54 y 71.6−375.4 41.2−243.7
55 to 64 y 48.9−344.2 29.4−220.5
65 to 74 y 30.9−295.6 20.4−186.6
≥75 y 20.8−226.4 13.9−142.8




004020: Dehydroepiandrosterone (DHEA) Sulfate | LabCorp



So far, IGF-1, Free T and Dhea all have ranges that change with age. PSA has a suggested age adjustment, but labs don’s seem to use it.


Do people know if these are the only blood tests where the range depends on age?

Those are the big ones for our purposes. Add SHBG although (for LabCorp) only divided into 2 reference ranges:

Age 20-49: 16.5 - 55.9 nmol/L
Age > 49: 19.3 - 76.4 nmol/L

This is indicative of the age-related increase in SHBG.
 

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Scientific Reference

Lakshman KM, Kaplan B, Travison TG, Basaria S, Knapp PE, Singh AB, LaValley MP, Mazer NA, Bhasin S. The effects of injected testosterone dose and age on the conversion of testosterone to estradiol and dihydrotestosterone in young and older men. J Clin Endocrinol Metab. 2010 Aug;95(8):3955-64.

DOI: 10.1210/jc.2010-0102 | PMID: 20534765 | PMCID: PMC2913038

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