Thyroid Function Test (FT3,FT4 & TSH)
Uncovering the Hidden Link with Diabetes
The Thyroid Function Test (TFT) is a series of blood tests that measure how well your thyroid gland is working. For people with diabetes, checking thyroid health is essential, as thyroid disorders can significantly impact blood sugar control, weight, metabolism and overall diabetes management.
What Does a Thyroid Function Test Include?
A typical TFT panel includes:
- TSH (Thyroid Stimulating Hormone): Secreted by the pituitary gland; Regulates thyroid hormone production
- Free T3 (Triiodothyronine) and Free T4 (Thyroxine): These are hormones secreted by the thyroid gland that control metabolism and energy usage, and support heart, muscle and brain function
Why Is Thyroid Testing Important for People with Diabetes?
There is a strong connection between thyroid disorders and diabetes:
- People with Type 1 diabetes have a higher risk of autoimmune thyroid disease (Hashimoto’s or Graves’ disease)
- Individuals with Type 2 diabetes often develop hypothyroidism, which can worsen insulin resistance, lead to weight gain, and elevate cholesterol
Thyroid disorders can:
- Affect blood sugar levels unpredictably
- Interfere with diabetes medications
- Increase the risk of heart and kidney complications
Worsen fatigue, depression, and slow metabolism
Normal Reference Ranges
| Test | Normal Range |
|---|---|
| TSH | 0.4 – 4.0 mIU/L |
| Free T3 | 2.0 – 4.4 pg/mL |
| Free T4 | 0.9 – 2.3 ng/dL |
When Should You Get a TFT?
- Annually, for routine diabetes health monitoring
- If you experience symptoms like fatigue, weight changes, hair loss or mood swings
- If you have a family history of thyroid disease
Tips to Support Thyroid and Diabetes Health
- Take thyroid medication at the same time daily
- Manage stress and get adequate sleep
- Monitor blood sugar regularly
- Eat a balanced diet with selenium, iodine and zinc