Alkaline phosphatase isoenzymes in plasma in hyperthyroidism

Area of Science:

• Biochemistry
• Endocrinology
• Clinical Chemistry

Background:

• Hyperthyroidism is a condition characterized by excessive thyroid hormone production.
• Alkaline phosphatase (ALP) is an enzyme found in various tissues, with different isoenzymes.
• Elevated ALP levels can indicate bone or liver disease, and may be affected by metabolic conditions.

Purpose of the Study:

• To investigate the levels of alkaline phosphatase (ALP) isoenzymes in patients with hyperthyroidism.
• To compare ALP isoenzyme profiles between untreated hyperthyroid, treated hyperthyroid, and healthy individuals.
• To explore the relationship between ALP levels, calcium, and parathyrin in hyperthyroidism.

Main Methods:

• Plasma samples were collected from 63 untreated hyperthyroid patients, 58 treated hyperthyroid patients, and 100 blood donors.
• Total, liver, bone, and intestinal alkaline phosphatase (ALP) isoenzyme activities were measured.
• Plasma calcium and serum parathyrin concentrations were also determined.

Main Results:

• Total, liver, and bone ALP activities were significantly higher in untreated hyperthyroid patients compared to treated patients and blood donors.
• Bone ALP abnormalities were more frequent and pronounced than liver ALP abnormalities.
• Intestinal ALP levels did not differ significantly across the groups. Untreated hyperthyroid patients exhibited higher plasma calcium and lower serum parathyrin levels.

Conclusions:

• Untreated hyperthyroidism is associated with significantly elevated alkaline phosphatase (ALP) activity, predominantly affecting bone isoenzymes.
• Bone ALP is a more sensitive indicator of ALP dysregulation in hyperthyroidism than liver ALP.
• Hyperthyroidism influences calcium and parathyrin homeostasis, which may contribute to the observed ALP alterations.