Endocrine Weight Loss Thyroid Function and Weight Loss

Question 1

Which thyroid hormone is considered the most metabolically active form at the cellular level?

Accepted Answer

T3 (triiodothyronine)

Answer

T3 (triiodothyronine) is 3–4 times more potent than T4 and is the primary hormone that binds thyroid hormone receptors in cell nuclei to regulate gene expression and metabolism.

Question 2

Subclinical hypothyroidism is defined as:

Accepted Answer

Elevated TSH with normal free T4, often asymptomatic

Answer

Subclinical hypothyroidism is characterized by a TSH above the upper reference limit (typically >4.5 mIU/L) with a normal free T4, and may present with subtle or no symptoms.

Question 3

Which autoantibody is most closely associated with Hashimoto's thyroiditis, the most common cause of hypothyroidism in the US?

Accepted Answer

Anti-thyroid peroxidase antibody (anti-TPO)

Answer

Anti-thyroid peroxidase (anti-TPO) antibodies are present in >90% of patients with Hashimoto's thyroiditis and are the hallmark autoimmune marker of this condition.

Question 4

A patient with hypothyroidism gains weight primarily because of:

Accepted Answer

Accumulation of myxedema fluid and reduced metabolic rate leading to fat deposition

Answer

Hypothyroid weight gain results from reduced metabolic rate (lower thermogenesis) plus accumulation of glycosaminoglycan-rich interstitial fluid (myxedema), though the latter is not true fat.

Question 5

Which thyroid function test is considered the single best screening test for thyroid dysfunction?

Accepted Answer

Thyroid-stimulating hormone (TSH)

Answer

TSH is the most sensitive indicator of thyroid status because it reflects pituitary integration of free thyroid hormone levels; even small changes in free T4/T3 cause large TSH changes.

Endocrine Weight Loss Practice Test

Endocrine Weight Loss Practice Test

Endocrine Weight Loss Thyroid Function and Weight Loss