학술논문
The Hypothalamic-Pituitary-Thyroid Axis in Cushing Syndrome Before and After Curative Surgery
Clinical Research Article
Clinical Research Article
Document Type
Report
Source
Journal of Clinical Endocrinology & Metabolism. March 2021, Vol. 106 Issue 3, pe1316, 16 p.
Subject
Language
English
ISSN
0021-972X
Abstract
In humans, individual studies suggest that endogenous hypercortisolism reduces thyroid hormone action through interactions at the hypothalamus, pituitary, liver, or other peripheral tissues. Inhibition of hypothalamic stimulation is suggested by [...]
Background: We do not fully understand how hypercortisolism causes central hypothyroidism or what factors influence recovery of the hypothalamic-pituitary-thyroid axis. We evaluated thyroid function during and after cure of Cushing syndrome (CS). Methods: We performed a retrospective cohort study of adult patients with CS seen from 2005 to 2018 (cohort 1, c1, n = 68) or 1985 to 1994 (cohort 2, c2, n = 55) at a clinical research center. Urine (UFC) and diurnal serum cortisol (F: ~8 AM and ~midnight [PM]), morning 3,5,3'-triiodothyronine (T3), free thyroxine (FT4), and thyrotropin (TSH) (c1) or hourly TSH from 1500 to 1900 h (day) and 2400 to 04000 h (night) (c2), were measured before and after curative surgery. Results: While hypercortisolemic, 53% of c1 had central hypothyroidism (low/low normal FT4 + unelevated TSH). Of those followed long term, 31% and 44% had initially subnormal FT4 and T3, respectively, which normalized 6 to 12 months after cure. Hypogonadism was more frequent in hypothyroid (69%) compared to euthyroid (13%) patients. Duration of symptoms, morning and midnight F, adrenocorticotropin, and UFC were inversely related to TSH, FT4, and/or T3 levels (r = -0.24 to -0.52, P< .001 to 0.02). In c2, the nocturnal surge of TSH (mIU/L) was subnormal before (day 1.00 [+ or -] 0.04 vs night 1.08 [+ or -] 0.05, P = .3) and normal at a mean of 8 months after cure (day 1.30 [+ or -] 0.14 vs night 2.17 [+ or -] 0.27, P= .01). UFC greater than or equal to 1000 [micro]g/day was an independent adverse prognostic marker of time to thyroid hormone recovery. Conclusions: Abnormal thyroid function, likely mediated by subnormal nocturnal TSH, is prevalent in Cushing syndrome and is reversible after cure. Freeform/Key Words: hypothyroidism, central hypothyroidism, Cushing syndrome, cortisol, hypothalamic-pituitarythyroid axis
Background: We do not fully understand how hypercortisolism causes central hypothyroidism or what factors influence recovery of the hypothalamic-pituitary-thyroid axis. We evaluated thyroid function during and after cure of Cushing syndrome (CS). Methods: We performed a retrospective cohort study of adult patients with CS seen from 2005 to 2018 (cohort 1, c1, n = 68) or 1985 to 1994 (cohort 2, c2, n = 55) at a clinical research center. Urine (UFC) and diurnal serum cortisol (F: ~8 AM and ~midnight [PM]), morning 3,5,3'-triiodothyronine (T3), free thyroxine (FT4), and thyrotropin (TSH) (c1) or hourly TSH from 1500 to 1900 h (day) and 2400 to 04000 h (night) (c2), were measured before and after curative surgery. Results: While hypercortisolemic, 53% of c1 had central hypothyroidism (low/low normal FT4 + unelevated TSH). Of those followed long term, 31% and 44% had initially subnormal FT4 and T3, respectively, which normalized 6 to 12 months after cure. Hypogonadism was more frequent in hypothyroid (69%) compared to euthyroid (13%) patients. Duration of symptoms, morning and midnight F, adrenocorticotropin, and UFC were inversely related to TSH, FT4, and/or T3 levels (r = -0.24 to -0.52, P< .001 to 0.02). In c2, the nocturnal surge of TSH (mIU/L) was subnormal before (day 1.00 [+ or -] 0.04 vs night 1.08 [+ or -] 0.05, P = .3) and normal at a mean of 8 months after cure (day 1.30 [+ or -] 0.14 vs night 2.17 [+ or -] 0.27, P= .01). UFC greater than or equal to 1000 [micro]g/day was an independent adverse prognostic marker of time to thyroid hormone recovery. Conclusions: Abnormal thyroid function, likely mediated by subnormal nocturnal TSH, is prevalent in Cushing syndrome and is reversible after cure. Freeform/Key Words: hypothyroidism, central hypothyroidism, Cushing syndrome, cortisol, hypothalamic-pituitarythyroid axis