Thyroid Trends

Purpose

The purpose of this section is to analyze thyroid-related laboratory trends over time and evaluate:

Effectiveness of thyroid replacement therapy.
Stability of thyroid function.
Relationship between TSH, Free T4, and Free T3.
Potential areas for physician discussion.

The primary markers reviewed include:

Thyroid-Stimulating Hormone (TSH)
Free Thyroxine (Free T4)
Free Triiodothyronine (Free T3)
Thyroid antibodies

Overview

The thyroid laboratory record demonstrates stable thyroid replacement control over time.

The overall pattern shows:

Normal TSH values.
Normal Free T4 values.
Persistent lower Free T3 levels on advanced testing.
Negative thyroid antibody testing.

The current thyroid picture is:

Thyroid replacement therapy is maintaining normal standard thyroid markers, while the lower Free T3 pattern remains an area for continued monitoring and physician discussion.

1. Thyroid History

Condition

Hypothyroidism

Current Treatment

Levothyroxine 75 mcg daily in the morning.

Clinical Goal

The purpose of thyroid replacement therapy is to maintain adequate thyroid hormone availability and prevent symptoms associated with low thyroid function.

Monitoring generally includes:

TSH.
Free T4.
Clinical symptoms.

2. Thyroid-Stimulating Hormone (TSH)

What TSH Measures

TSH is produced by the pituitary gland and regulates thyroid hormone production.

A normal TSH generally indicates appropriate thyroid hormone feedback regulation.

TSH Trend

Date	TSH	Interpretation
June 2024	0.819 μIU/mL	Normal
November 2024	1.110 μIU/mL	Normal
2025 Function Health	Normal	Stable
June 2026	Normal	Stable

Interpretation

TSH has remained consistently controlled.

This suggests:

Appropriate thyroid hormone replacement.
Stable pituitary-thyroid regulation.
No evidence of under-treatment or significant over-treatment.

3. Free T4 Trend

What Free T4 Measures

Free T4 represents the circulating available form of thyroxine, the primary hormone produced by the thyroid gland and replaced with levothyroxine.

Free T4 Trend

Date	Free T4	Interpretation
June 2024	1.31 ng/dL	Normal
November 2024	1.24 ng/dL	Normal
2025 Testing	Normal	Stable
June 2026	Normal	Stable

Interpretation

Free T4 has remained in a healthy range.

This supports the conclusion that levothyroxine therapy is effectively maintaining thyroid hormone availability.

4. Free T3 Trend

What Free T3 Measures

Free T3 is the active thyroid hormone used by tissues throughout the body.

The body converts T4 into T3 through metabolic processes.

Findings

Advanced Function Health testing identified:

Free T3 below the reference range.

This finding has persisted despite:

Normal TSH.
Normal Free T4.

Interpretation

The Free T3 pattern is an important observation.

Possible explanations may include:

Individual variation in thyroid hormone conversion.
Effects of calorie restriction or fasting.
Low-carbohydrate nutritional patterns.
Metabolic adaptation.
Age-related changes.

This finding should be interpreted together with:

Symptoms.
Energy level.
Body temperature.
Heart rate.
Overall clinical status.

5. Thyroid Antibodies

Testing Included

Thyroid Peroxidase Antibodies (TPO)
Thyroglobulin Antibodies

Findings

Thyroid antibodies negative.

Interpretation

The absence of thyroid antibodies suggests no current laboratory evidence of autoimmune thyroid destruction.

This is important given the broader autoimmune evaluation.

6. Relationship Between Thyroid and Other Health Trends

Thyroid and Metabolic Health

Your thyroid results should be viewed alongside:

Excellent glucose control.
Low insulin levels.
Low inflammation.
Stable weight/metabolic status.

The laboratory picture does not suggest impaired metabolic health.

Thyroid and Cardiovascular Health

Because thyroid hormones influence:

Heart rhythm.
Cholesterol metabolism.
Cardiovascular function.

continued monitoring is appropriate, especially given your history of:

Atrial fibrillation.
Cardiovascular follow-up with Dr. Yoo.

Thyroid and Autoimmunity

The broader autoimmune picture shows:

Positive ANA.
Negative thyroid antibodies.

This suggests that the ANA finding is not explained by autoimmune thyroid disease.

Thyroid Summary Table

Category	Historical Finding	Current Status
Hypothyroidism	Established diagnosis	Managed
Levothyroxine	75 mcg daily	Continued
TSH	Normal	Controlled
Free T4	Normal	Controlled
Free T3	Lower	Monitor
Thyroid antibodies	Negative	No evidence of thyroid autoimmunity

Current Thyroid Assessment (2026)

Area	Status
Thyroid replacement	Effective
TSH control	Excellent
Free T4	Excellent
Free T3 conversion	Monitor
Autoimmune thyroid disease	Not demonstrated

Physician Discussion Points

Questions for Dr. George

Should Free T3 continue to be monitored along with TSH and Free T4?
Does the lower Free T3 value require any action given normal TSH and Free T4?
Could dietary pattern, fasting, or metabolic adaptation influence Free T3 levels?

Questions for Dr. Yoo

Given the history of atrial fibrillation, is the current thyroid replacement level appropriate?
Should thyroid values be considered when evaluating cardiovascular risk?

Overall Interpretation

The thyroid trend demonstrates stable and effective management of hypothyroidism.

The laboratory record shows:

Normal TSH.
Normal Free T4.
Negative thyroid antibodies.
Persistent lower Free T3 requiring observation.

The most accurate summary is:

Thyroid replacement therapy is providing excellent standard laboratory control. The persistent lower Free T3 pattern represents an area for continued monitoring and discussion but is not accompanied by evidence of thyroid instability.

Related Sections

This trend analysis connects directly with:

Section 3.5 — Hypothyroidism
Section 3.6 — Autoimmune Serology
Section 7.2.2 — Autoimmune Trends
Section 7.2.5 — Metabolic Trends
Section 8 — Physician Consultation Summaries