The TSH Reference Range Wars: What's "Normal?", Who is Wrong, Who is Right...

[Nelson Vergel]

There is ongoing controversy about whether reliance on the TSH test -- to the exclusion of clinical symptoms and other tests such as Free T4, Free T3, and antibodies tests -- is medically sound. That is a controversy that is unlikely to be decided for years. The situation today, however, is that the majority of physicians do rely almost exclusively on the TSH test to detect thyroid disease, and monitor the effectiveness of treatment.


Surprisingly, however, while the medical community does rely on the TSH test, there is complete disagreement within the community as to what constitutes the "normal range."

What Do High and Low TSH Levels Mean?

 

[Nelson Vergel]

The Big Lie Your Doctor is Telling You About Thyroid Treatment

 

[OMI100]

Good articles..... All one has to do is find a DR that understands that the TSH test is NOT the gospel.... That in itself is a daunting task... Much like finding a needle in a hay stack...

 

[Nelson Vergel]

Thyroid Lab Tests: A View From the Inside

 

[Nelson Vergel]

Only reverse T3 was associated with mortality.



J Clin Endocrinol Metab. 2016 Nov;101(11):4385-4394. Epub 2016 Aug 23

Serum Thyroid Function, Mortality and Disability in Advanced Old Age: The Newcastle 85+ Study.

Pearce SH1, Razvi S1, Yadegarfar ME1, Martin-Ruiz C1, Kingston A1, Collerton J1, Visser TJ1, Kirkwood TB1, Jagger C1.


Abstract

CONTEXT:
Perturbations in thyroid function are common in older individuals but their significance in the very old is not fully understood.

OBJECTIVE:

This study sought to determine whether thyroid hormone status and variation of thyroid hormones within the reference range correlated with mortality and disability in a cohort of 85-year-olds.

DESIGN:
A cohort of 85-year-old individuals were assessed in their own homes (community or institutional care) for health status and thyroid function, and followed for mortality and disability for up to 9 years.

SETTING AND PARTICIPANTS:

Six hundred and forty-three 85-year-olds registered with participating general practices in Newcastle and North Tyneside, United Kingdom.

MAIN OUTCOMES:
All-cause mortality, cardiovascular mortality, and disability according to thyroid disease status and baseline thyroid hormone parameters (serum TSH, FT4, FT3, and rT3). Models were adjusted for age, sex, education, body mass index, smoking, and disease count.

RESULTS:
After adjustment for age and sex, all-cause mortality was associated with baseline serum rT3 and FT3 (both P < .001), but not FT4 or TSH. After additional adjustment for potential confounders, only rT3 remained significantly associated with mortality (P = .001). Baseline serum TSH and rT3 predicted future disability trajectories in men and women, respectively.

CONCLUSIONS:

Our study is reassuring that individuals age 85 y with both subclinical hypothyroidism and subclinical hyperthyroidism do not have a significantly worse survival over 9 years than their euthyroid peers. However, thyroid function tests did predict disability, with higher serum TSH levels predicting better outcomes. These data strengthen the argument for routine use of age-specific thyroid function reference ranges.

 

[Nelson Vergel]

Thyroid. 2016 Nov 3. [Epub ahead of print]

The association between changes in thyroid hormones and incident type 2 diabetes: A 7-year longitudinal study.

Jun JE1, Jin SM2, Bae JC3, Jee JH4, Hur KY5, Lee MK6, Kim TH7, Kim SW8,9, Kim JH10.



Abstract
BACKGROUND:
Thyroid hormones are important regulators of glucose homeostasis; however, the association between thyroid hormones within the reference range and type 2 diabetes remains unclear. The aim of this study was to clarify the incidence of type 2 diabetes according to the baseline levels and changes of thyroid stimulating hormone (TSH) and thyroid hormones (free thyroxine [FT4] and triiodothyronine [T3]) in euthyroid subjects.

METHODS:
Among the participants who consecutively underwent thyroid function tests between 2006 and 2012 through a yearly health check-up program, 6,235 euthyroid subjects (3,619 men and 2,616 women) without diabetes were enrolled in the study. The change in each hormone was calculated by subtracting the baseline value from the level at the end of follow-up or 1 year before the diagnosis of diabetes.

RESULTS:
During 25,692 person-years of follow-up, there were 229 new cases of type 2 diabetes. After full adjustment for potential confounders including HbA1c and fasting glucose in Cox proportional hazards models, the individuals in the highest tertile of TSH change (2.5 to 4.2IU/mL) had a greater risk of incident type 2 diabetes (hazard ratio

---

=1.44, 95% confidence interval [CI]: 1.04 - 1.98, p for trend = 0.027) in comparison with individuals in the lowest tertile (-4.1 to -0.5 IU/mL). Simultaneously, the highest tertile of T3 change (16.3 to 104.7 ng/dL) and FT4 change (0.2 to 1.6 ng/dL) conferred protective effects against diabetes (HR = 0.60, 95% CI: 0.43-0.85, p for trend = 0.002 and HR = 0.34, 95% CI: 0.24 - 0.48, p for trend < 0.001, respectively) compared to those in the lowest tertile (-76.5 to -1.8 ng/dL and -0.6 to 0.0 ng/dL, respectively). These associations remained significant when each of the hormones was analyzed as a continuous variable. However, baseline levels or tertiles of TSH and thyroid hormones were not associated with the risk of diabetes.

---

CONCLUSIONS:
Individual changes in TSH and thyroid hormones even within the normal reference range were an additional risk factor of incident type 2 diabetes.

 

[Nelson Vergel]

Thyroid Tests and What They Mean

 

[GreenMachineX]

Only reverse T3 was associated with mortality.



J Clin Endocrinol Metab. 2016 Nov;101(11):4385-4394. Epub 2016 Aug 23

Serum Thyroid Function, Mortality and Disability in Advanced Old Age: The Newcastle 85+ Study.

Pearce SH1, Razvi S1, Yadegarfar ME1, Martin-Ruiz C1, Kingston A1, Collerton J1, Visser TJ1, Kirkwood TB1, Jagger C1.


Abstract

CONTEXT:
Perturbations in thyroid function are common in older individuals but their significance in the very old is not fully understood.

OBJECTIVE:

This study sought to determine whether thyroid hormone status and variation of thyroid hormones within the reference range correlated with mortality and disability in a cohort of 85-year-olds.

DESIGN:
A cohort of 85-year-old individuals were assessed in their own homes (community or institutional care) for health status and thyroid function, and followed for mortality and disability for up to 9 years.

SETTING AND PARTICIPANTS:

Six hundred and forty-three 85-year-olds registered with participating general practices in Newcastle and North Tyneside, United Kingdom.

MAIN OUTCOMES:
All-cause mortality, cardiovascular mortality, and disability according to thyroid disease status and baseline thyroid hormone parameters (serum TSH, FT4, FT3, and rT3). Models were adjusted for age, sex, education, body mass index, smoking, and disease count.

RESULTS:
After adjustment for age and sex, all-cause mortality was associated with baseline serum rT3 and FT3 (both P < .001), but not FT4 or TSH. After additional adjustment for potential confounders, only rT3 remained significantly associated with mortality (P = .001). Baseline serum TSH and rT3 predicted future disability trajectories in men and women, respectively.

CONCLUSIONS:

Our study is reassuring that individuals age 85 y with both subclinical hypothyroidism and subclinical hyperthyroidism do not have a significantly worse survival over 9 years than their euthyroid peers. However, thyroid function tests did predict disability, with higher serum TSH levels predicting better outcomes. These data strengthen the argument for routine use of age-specific thyroid function reference ranges.

High rt3 was associated more with mortality???

 

[Systemlord]

There was another guy on another forum who started TRT, 3 weeks in TSH was measured at 2.7, previously 2.3 and his Free T3 has dropped to the bottom of the ranges, here his TSH was in range.

 

[GreenMachineX]

There was another guy on another forum who started TRT, 3 weeks in TSH was measured at 2.7, previously 2.3 and his Free T3 has dropped to the bottom of the ranges, here his TSH was in range.

Interesting. My TSH is 1.5, free t3 top of range, but rt3 also in 20's.

 

[Nelson Vergel]

Many of us on TRT have high reverse T3:

reverse t3

www.excelmale.com

 

[Systemlord]

Interesting. My TSH is 1.5, free t3 top of range, but rt3 also in 20's.

My TSH went down from 0.89-> 0.45 on TRT.

 

[GreenMachineX]

View attachment 5109


There is ongoing controversy about whether reliance on the TSH test -- to the exclusion of clinical symptoms and other tests such as Free T4, Free T3, and antibodies tests -- is medically sound. That is a controversy that is unlikely to be decided for years. The situation today, however, is that the majority of physicians do rely almost exclusively on the TSH test to detect thyroid disease, and monitor the effectiveness of treatment.


Surprisingly, however, while the medical community does rely on the TSH test, there is complete disagreement within the community as to what constitutes the "normal range."

What Do High and Low TSH Levels Mean?

My wife just had thyroid labs done. Her tsh was 2.74, free t4 1.01 and free t3 2.8. Of course, her doctor said she's normal, but according to those images, suboptimal and I think the reason why she's been gaining fat and losing muscle too easily even while still training and eating fairly well for the most part. Unsure what to do for her.

 

[Nelson Vergel]

Her tsh was 2.74, free t4 1.01 and free t3 2.8.

I suggest that she gets thyroid antibodies and reverse T3 checked to make sure she does not have Hashimoto's.

 

[GreenMachineX]

I suggest that she gets thyroid antibodies and reverse T3 checked to make sure she does not have Hashimoto's.

Thanks. Her thyroid antibodies were normal too, but reverse t3 wasn't tested.

 

[Nelson Vergel]

If her antibodies are normal, that is a good thing. Is your wife on HRT?

 

[GreenMachineX]

If her antibodies are normal, that is a good thing. Is your wife on HRT?

No, she's not. That's another thing...her testosterone is very bottom of range normal, just like the thyroid numbers, normal but not optimal.

 

[doyouwantbirds]

Thanks for the info. I've heard somewhere that they have moved the "normal" for TSH, much like they did with Test.

 

[Cataceous]

Many of us on TRT have high reverse T3:

...

This seemed to be my situation. Elevated reverse T3 correlated with side effects that were ameliorated by liothyronine. However, the problem resolved when I lowered my TRT dose and switched to a propionate/enanthate blend. Does excessive testosterone act as a stressor?

 

[tareload]

Elevated reverse T3

DESSICATED THYROID CONTINUES HAVING ZERO EFFECT ON TSH; ELEVATED FT3, NORMAL FT4

As I indicated in my post, I have already experimented with every possible combination, including adding T3 in various doses, over the last 10+ years. The only instance in that time frame I sufficiently suppressed was when I took T4 alone, go figure, but I wasn't able to maintain it for whatever...

www.excelmale.com

Would be fun to extend the above info to the TRT/TOT world. Does RT3 give us any actionable information...?

Obviously RT3 exists for a reason. Fun to go back and study why it exists.