Serum ionized calcium and corrected total calcium in borderline hyperparathyroidism

Area of Science:

• Endocrinology
• Clinical Chemistry

Background:

• Borderline hyperparathyroidism presents diagnostic challenges.
• Total serum calcium levels can be within normal limits despite the condition.
• Serum albumin levels can affect total calcium measurements.

Purpose of the Study:

• To compare the diagnostic accuracy of corrected serum calcium versus serum ionized calcium in borderline hyperparathyroidism.
• To evaluate the effectiveness of albumin correction in identifying hyperparathyroid patients.

Main Methods:

• Studied 25 patients with histopathologically verified borderline hyperparathyroidism.
• Analyzed serum calcium and albumin concentrations in a reference group of 2098 patients.
• Calculated corrected serum calcium using an albumin correction factor.

Main Results:

• Serum ionized calcium levels were elevated in borderline hyperparathyroidism patients with normal total calcium.
• Corrected serum calcium values improved discrimination but still fell within normal ranges for 13 of 25 patients.
• Serum ionized calcium demonstrated superior diagnostic capability.

Conclusions:

• Correcting total serum calcium for albumin enhances the identification of borderline hyperparathyroid patients.
• Serum ionized calcium measurement offers superior diagnostic discrimination for borderline hyperparathyroidism.