Endocrine Abstracts

Introduction: MSC is a simple and reliable mean to diagnose hypercortisolism, yet its value to asses the outcome of treatment has rarely been addressed.

Objective: Compare MSC and other classical parameters, to assess the outcome of TSS in CD.

Patients and methods: Sixty-eight patients from a single Center operated for CD between 1996 and 2006. Outcome was assessed between 6–12 months post TSS. Remission was defined as: morning plasma cortisol <50 ng/ml and/or insufficient response to ACTH; or normal urinary free cortisol (UFC<90 μg/d) together with midnight plasma cortisol <75 ng/ml and normal suppression to dexamethasone. Morning plasma cortisol at day five post TSS (TSS +5) was also retrospectively analysed.

Results: The 73.5% of the patients achieved remission. MSC was significantly lower remission group (group 1, n=50) than of failure (group 2, n=18): 0.7±0.4 ng/ml (mean ±S.D., range: 0.4–2.2 ng/ml) versus 6.5±6.6 ng/ml (range: 2.1–27.2 ng/ml), P<0.001. Similarly, UFC was significantly lower in group 1 than in group 2: 14±19 μg/d (range: 2–105 mg/d) versus 307±304 μg/d (range: 20–1070 μg/d), P<0.001. Retrospectively, morning plasma cortisol at TSS+5 was lower in group 1 than in group 2: 26.8±46.4 ng/ml (range: 10–270 ng/ml) versus 136.6±85.6 ng/ml (range:14–298 ng/ml), P<0.001. MSC was correlated to UFC (r 0.618, P<0.001), as well as to morning plasma cortisol at TSS+5 (r 0.410, P<0.001). For the diagnosis of remission the performances (specificity-sensitivity) of the different measurements were as follows: MSC (cut off of 2 ng/ml) 100%–98%; morning plasma cortisol post TSS +5 (cut off 18 ng/ml) 92.9%–26%; UFC (cut off of 90 μg/day) 70.6%–21%.

Conclusion: MSC is a valid marker of remission after TSS for CD, with better sensitivity and specificity than UFC or early morning plasma cortisol immediately after TSS.