Serum angiotensin-converting enzyme. Alterations in hyperthyroidism, hypothyroidism, and subacute thyroiditis

Area of Science:

• Endocrinology
• Biochemistry

Background:

• Thyroid hormones significantly influence various physiological processes.
• Angiotensin-converting enzyme (ACE) is a key enzyme in the renin-angiotensin system.
• Previous research has suggested potential links between thyroid status and ACE activity.

Purpose of the Study:

• To investigate the relationship between thyroid function and serum ACE activity.
• To determine if serum ACE levels vary across different thyroid states (hyperthyroidism, euthyroidism, hypothyroidism).
• To explore the potential of serum ACE as a marker for thyroid hormone action.

Main Methods:

• Serum samples from 247 patients with diverse thyroid states were analyzed for ACE activity.
• Patients were categorized into hyperthyroid, euthyroid, and hypothyroid groups.
• ACE levels were compared between groups and in patients before and after treatment or during disease progression.

Main Results:

• Hyperthyroid patients exhibited significantly higher mean serum ACE levels (29.5 +/- 9.7 U/mL) compared to euthyroid (17.0 +/- 5.1 U/mL) and hypothyroid (13.9 +/- 5.1 U/mL) groups.
• Serum ACE levels decreased in hyperthyroid patients following therapy (30.8 to 17.4 U/mL).
• Serum ACE levels increased in hypothyroid patients after thyroid hormone replacement (11.6 to 15.8 U/mL).
• In transient hyperthyroidism, ACE levels peaked during the hyperthyroid phase and declined during recovery.

Conclusions:

• Serum ACE activity is demonstrably influenced by thyroid hormone levels.
• Interpretation of serum ACE levels necessitates consideration of the patient's thyroid status.
• Serum ACE may serve as a valuable indicator for investigating peripheral thyroid hormone effects.