Muscle strength, physical performance, and metabolic changes after subtotal parathyroidectomy for secondary hyperparathyroidism.

BACKGROUND: Hyperparathyroidism in patients on chronic hemodialysis presents with bone pain, pruritus, and extra-skeletal calcifications. Little attention has been paid to low plasma protein concentrations and muscle weakness in these patients. The present study was undertaken to characterize the impact of subtotal parathyroidectomy for chronic hemodialysis on body composition, muscle strength, plasma proteins, quality of life, and long-term clinical course.

METHODS: We performed a prospective observational before-after assessment study of consecutive chronic hemodialysis patients referred for parathyroidectomy. Patients were investigated at baseline before parathyroidectomy and then at 1 and 6 months after surgery, with the aim to assess changes in metabolic parameters, body composition by bioimpedance, muscle strength, and quality of life (36-items Short Form Health Survey questionnaire). Follow-up was terminated when patients reached 1 of the 3 pre-defined end points: recurrence of secondary hyperparathyroidism, transplantation, or death.

RESULTS: A group of 23 patients on hemodialysis were included. Preoperative handgrip strength was diminished by 52.4 ± 17%. After parathyroidectomy, a drop of immunoreactive parathyroid hormone concentrations (1,153 vs 237 pg/mL; P < .001) was observed together with increases in plasma protein (total: 6.8 vs7.8 g/dL, s-albumin 3.7 vs 4.4 g/dL and prealbumin: 31.7 vs 35.2 mg/dL; P < .001), handgrip strength (18.3 vs 22.9 kg: P = .001) as well as an improvement in physical dimension (32.9 vs 35.6; P = .004) and vitality (32.3 vs 47.1; P = .002) domains of the 36-items Short Form Health Survey questionnaire. After10 years, one-third of the patients had died, one-third of the patients had a recurrence of secondary hyperparathyroidism, and one-third of patients had received a kidney transplant and maintained a normal parathyroid function.

CONCLUSION: Subtotal parathyroidectomy improves protein metabolic markers, muscle strength, and physical performance in chronic hemodialysis patients.