Muscle Function Improves After Parathyroidectomy: The Role of Calcium Reduction Over Parathyroid Hormone Decline

Area of Science:

• Endocrinology
• Neuromuscular Medicine
• Surgical Research

Background:

• Primary hyperparathyroidism (PHPT) is linked to subclinical neuromuscular issues.
• Clinical manifestations of muscle strength and morphology in PHPT are not well understood.

Purpose of the Study:

• To investigate if muscle dysfunction in PHPT is reversible after parathyroidectomy (PTX).
• To determine if reduced serum calcium predicts early postoperative functional improvement.

Main Methods:

• Prospective observational study comparing 53 PHPT patients to 53 controls.
• Assessed handgrip strength (HGS), 4-meter walking speed (4MGS), timed-up-and-go (TUG), 5-time sit-to-stand (5XSTS), muscle thickness (ultrasound), and body composition (BIA).
• 34 patients underwent PTX and were reassessed; Generalized Linear Mixed Models (GLMM) analyzed predictors of muscle function changes.

Main Results:

• PHPT patients had lower HGS, slower TUG/5XSTS, and reduced gastrocnemius muscle (GM) thickness versus controls.
• Post-PTX, GM thickness and lower limb function (TUG, 5XSTS) significantly improved.
• Reduced serum calcium independently predicted functional improvement.

Conclusions:

• Parathyroidectomy improves muscle thickness and lower extremity function in PHPT patients.
• Recovery appears multimodal, with serum calcium reduction as a key predictor.
• Further research is needed to assess if these findings aid surgical decision-making and patient selection.