2 research outputs found
The Effect of Biochemical Remission on Bone Metabolism in Cushing's Syndrome: A 2âYear FollowâUp Study
Endogenous Cushing's syndrome (CS) is a rare cause of secondary osteoporosis. The longâterm consequences for bone metabolism after successful surgical treatment remain largely unknown. We assessed bone mineral density and fracture rates in 89 patients with confirmed Cushing's syndrome at the time of diagnosis and 2âyears after successful tumor resection. We determined five bone turnover markers at the time of diagnosis, 1 and 2âyears postoperatively. The bone turnover markers osteocalcin, intact procollagenâINâpropeptide (PINP), alkaline bone phosphatase, CTXâI, and TrAcP 5b were measured in plasma or serum by chemiluminescent immunoassays. For comparison, 71 sexâ, ageâ, and body mass index (BMI)âmatched patients in whom Cushing's syndrome had been excluded were studied. None of the patients received specific osteoanabolic treatment. At time of diagnosis, 69% of the patients had low bone mass (mean Tâscore = â1.4â±â1.1). Two years after successful surgery, the Tâscore had improved in 78% of patients (mean Tâscore 2âyears postoperatively â1.0â±â0.9). The bone formation markers osteocalcin and intact PINP were significantly decreased at time of diagnosis (p â€â0.001 and p =â0.03, respectively), and the bone resorption marker CTXâI and TrAcP 5b increased. Postoperatively, the bone formation markers showed a threeâ to fourfold increase 1âyear postoperatively, with a moderate decline thereafter. The bone resorption markers showed a similar but less pronounced course. This study shows that the phase immediately after surgical remission from endogenous CS is characterized by a high rate of bone turnover resulting in a striking net increase in bone mineral density in the majority of patients
Patients with low IGF-I after curative surgery for Cushing's syndrome have an adverse long-term outcome of hypercortisolism-induced myopathy
Background
Glucocorticoid excess leads to muscle atrophy and weakness in patients with endogenous Cushing's syndrome. Insulin-like growth factor I (IGF-I) is known to have protective effects on muscle loss. We hypothesized that individual serum IGF-I concentrations might be predictive for long-term myopathy outcome in Cushing's syndrome.
Patients and methods
In a prospective longitudinal study of 31 patients with florid Cushing's syndrome, we analyzed IGF-I and IGF binding protein 3 (IGFBP 3) concentrations at the time of diagnosis and following surgical remission over a period of up to 3 years. We assessed muscle strength by grip strength measurements using a hand grip dynamometer and muscle mass by bio-impedance measurements.
Findings
Individual serum IGF-I concentrations in the postoperative phase were strongly predictive of long-term grip strength outcome (rs = 0.696, P †0.001). Also, lower IGF-I concentrations were associated with a lower muscle mass after 3 years (rs = 0.404, P = 0.033). While patients with high IGF-I s.d. scores (SDS; >1.4) showed an improvement in grip strength within the follow-up period (P = 0.009), patients with lower IGF-I SDS (â€-0.4) had a worse outcome with persisting muscle dysfunction. In contrast, preoperative IGF-I concentrations during the florid phase of Cushing's syndrome did not predict long-term muscle function outcome (rs = 0.285, P = 0.127).
Conclusion
Lower individual IGF-I concentrations 6 months after curative surgery for Cushing's syndrome are associated with adverse long-term myopathy outcome and IGF-I might be essential for muscle regeneration in the early phase after correction of hypercortisolism