Search the Community
Showing results for tags 'hpa axis'.
The search index is currently processing. Current results may not be complete.
Central hypothyroidism is prevalent in about 1 in 2 adults with Cushing’s syndrome, and thyroid function can be restored after curative surgery for most patients, according to study findings. “Our study findings have confirmed and greatly extended previous smaller studies that suggested a link between hypercortisolism and thyroid dysfunction but were inconclusive due to smaller sample size and short follow-up,” Skand Shekhar, MD, an endocrinologist and clinical investigator in the reproductive physiology and pathophysiology group at the National Institute of Environmental Health Sciences, NIH, told Healio. “Due to our large sample and longer follow-up, we firmly established a significant negative correlation between hypercortisolemia measures — serum and urinary cortisol, serum adrenocorticotropic hormone — and thyroid hormones triiodothyronine, free thyroxine and thyrotropin.” Shekhar and colleagues conducted a retrospective review of two groups of adults aged 18 to 60 years with Cushing’s syndrome. The first group was evaluated at the NIH Clinical Center from 2005 to 2018 (n = 68; mean age, 43.8 years; 62% white), and the second group was evaluated from 1985 to 1994 (n = 55; mean age, 37.2 years; 89% white). The first cohort was followed for 6 to 12 months to observe the pattern of thyroid hormone changes after surgical cure of adrenocorticotropic hormone-dependent Cushing’s syndrome. The second group underwent diurnal thyroid-stimulating hormone evaluation before treatment and during remission for some cases. Urinary free cortisol and morning thyroid hormone levels were collected for all participants. In the second group, researchers evaluated diurnal patterns of TSH concentrations with hourly measurements from 3 to 7 p.m. and midnight to 4 p.m. In the first group, adrenocorticotropic hormone and serum cortisol were measured. In the first cohort, seven participants were receiving levothyroxine for previously diagnosed primary or central hypothyroidism. Of the remaining 61 adults, 32 had untreated central hypothyroidism. Thirteen participants had free T4 at the lower limit of normal, and 19 had subnormal levels. There were 29 adults with subnormal levels of T3 and seven with subnormal TSH. Before surgery, 36 participants in the first group had central hypothyroidism. Six months after surgery, central hypothyroidism remained for 10 participants. After 12 months, the number of adults with central hypothyroidism dropped to six. Preoperative T3 and TSH levels were negatively associated with morning and midnight cortisol, adrenocorticotropic hormone and urinary free cortisol. In post hoc analysis, a baseline urinary free cortisol of more than 1,000 g per day was adversely associated with baseline and 6-month T3 and free T4 levels. In the second group, there were 51 participants not on thyroid-modifying drugs who had a thyroid function test 6 or 12 months after surgery. Before surgery, free T4 levels were subnormal in 17 participants, T3 levels were subnormal in 22, and TSH levels were in the lower half of the reference range or below in all but one participant. After surgery, two participants had below normal free T4, one had subnormal T3, and TSH levels were in the lower half of the reference range or below in 23 of 48 participants. Before surgery, there was no difference in mean TSH between daytime and nighttime. A mean 8 months after surgery, the second group had a normal nocturnal TSH surge from 1.3 mIU/L during the day to 2.17 mIU/L at night (P = .01). The nocturnal TSH increase persisted as long as 3 years in participants who had follow-up evaluations. “We found a very high prevalence of thyroid hormone deficiency that appears to start at the level of the hypothalamus-pituitary gland and extend to the tissue level,” Shekhar said. “Some of these patients may experience thyroid hormone deficiency symptoms, such as fatigue, depression, cold intolerance, weight gain, etc, as a result of systematic and tissue-level thyroid hormone deficiency. We also noted a strong correlation between hypothyroidism and hypogonadism, which implies that hypothyroid patients are also likely to suffer adverse reproductive effects. Thus, it is imperative to perform thorough thyroid hormone assessment in patients with Cushing’s syndrome, and thyroid hormone supplementation should be considered for these patients unless cure of Cushing’s syndrome is imminent.” Researchers said providers should routinely screen for hypothyroidism in adults with Cushing’s syndrome. Even after thyroid function is restored, regular follow-up should also be conducted. Further research is needed to investigate thyroid dysfunction in iatrogenic Cushing’s syndrome and the impact of these findings on euthyroid sick syndrome, Shekhar said. For more information: Skand Shekhar, MD, can be reached at email@example.com. From https://www.healio.com/news/endocrinology/20210208/thyroid-dysfunction-highly-prevalent-in-cushings-syndrome
Recovery of the hypothalamus-pituitary-adrenal (HPA) axis can occur as late as 12 months after transsphenoidal adenomectomy (TSA), according to study results published in The Journal of Clinical Endocrinology & Metabolism. These findings emphasize the need to periodically assess these patients to avoid unnecessary hydrocortisone replacement. The primary treatment for most pituitary lesions is TSA. After pituitary surgery, the recovery of pituitary hormone deficits may be delayed; limited data are available regarding the postsurgical recovery of hormonal axes or predictors of recovery. The goal of this study was to assess HPA axis dysfunction and predictive markers of recovery following TSA, as well as time to recovery, to identify subgroups of patients who may be more likely to recover. This single-center observational retrospective study enrolled 109 patients in the United Kingdom (71 men; mean age, 56 years; range, 17 to 82 years) who underwent TSA between February 2015 and September 2018 and had ≥1 reevaluation of the HPA axis with the short Synacthen (cosyntropin) test. The primary outcome was recovery of HPA axis function 6 weeks, 3 months, 6 months, and 9 to 12 months after TSA. In 23 patients (21.1%), there was no evidence of pituitary hormone deficit before TSA. In 44 patients (40.4%), there was 1 hormone deficiency and in 25 patients (22.9%), preoperative evaluation showed >1 hormone deficiency. Of the 23 patients with abnormal HPA function before surgery, 8 patients (34.8%) had recovered 6 weeks after the surgery. Patients who recovered were younger (mean age, 50±14 vs 70±9 years; P =.008) compared with patients who did not respond. Of the 15 remaining patients, 2 (13.3%) recovered at 3 months and 3 (20%) recovered at 9 to 12 months. With regard to HPA function in the entire cohort 6 weeks after surgery, 32 patients (29.4%) did not pass the short Synacthen test. Of this group, 5 patients (15.6%) recovered at 3 months, 4 (12.5%) at 6 months, and 2 (6.2%) recovered 9 to 12 months after the surgery. Predictors of future adrenal recovery at 6 weeks included having preoperative 30-minute cortisol >430 nmol/L (P <.001) and a day 8 postoperative cortisol >160 nmol/L (P =.001). With these cutoffs, 80% of patients with preoperative 30-minute cortisol >430 nmol/L (odds ratio [OR], 7.556; 95% CI, 2.847-20.055) and 80% of patients with day 8 postoperative cortisol >160 nmol/L (OR, 9.00; 95% CI, 2.455-32.989) passed the short Synacthen test at 6 weeks postsurgery. In addition, a 6-week baseline short Synacthen test cortisol level above or below 180 nmol/L (P <.001) predicted adrenal recovery at that time point. None of the patients with all 3 variables below the aforementioned cutoffs recovered HPA axis within 1 year. On the other hand, 91.8% of patients with all 3 variables above those cutoffs had normal adrenal function at 6 weeks (OR, 12.200; 95% CI, 5.268-28.255). In addition to the retrospective design, the study had other limitations, including the potential for selection bias, a heterogeneous patient cohort, and no data beyond 12 months after the surgery. “[T]hese data offer the opportunity for patients who may have been given life-long replacement, to safely come off therapy and therefore avoid unnecessary glucocorticoid exposure,” wrote the researchers. Reference Pofi R, Gunatilake S, Macgregor V, et al. Recovery of the hypothalamo-pituitary-adrenal axis following transsphenoidal adenomectomy for non-ACTH secreting macroadenomas [published online June 21, 2019]. J Clin Endocrinol Metab. doi:10.1210/jc.2019-00406 From https://www.endocrinologyadvisor.com/home/topics/adrenal/recovery-of-hpa-axis-can-occur-late-after-transsphenoidal-adenomectomy/
All patients who undergo removal of one adrenal gland due to Cushing’s syndrome (CS) or adrenal incidentaloma (AI, adrenal tumors discovered incidentally) should receive a steroid substitutive therapy, a new study shows. The study, “Predictability of hypoadrenalism occurrence and duration after adrenalectomy for ACTH‐independent hypercortisolism,” was published in the Journal of Endocrinological Investigation. CS is a rare disease, but subclinical hypercortisolism, an asymptomatic condition characterized by mild cortisol excess, has a much higher prevalence. In fact, subclinical hypercortisolism, is present in up to 20 percent of patients with AI. The hypothalamic-pituitary-adrenal axis (HPA axis) is composed of the hypothalamus, which releases corticotropin-releasing hormone (CRH) that acts on the pituitary to release adrenocorticotropic hormone (ACTH), that in turn acts on the adrenal gland to release cortisol. To avoid excess cortisol production, high cortisol levels tell the hypothalamus and the pituitary to stop producing CRH and ACTH, respectively. Therefore, as CS and AI are characterized by high levels of cortisol, there is suppression of the HPA axis. As the adrenal gland is responsible for the production of cortisol, patients might need steroid substitutive therapy after surgical removal of AI. Indeed, because of HPA axis suppression, some patients have low cortisol levels after such surgeries – clinically known as post-surgical hypocortisolism (PSH), which can be damaging to the patient. While some researchers suggest that steroid replacement therapy should be given only to some patients, others recommend it should be given to all who undergo adrenalectomy (surgical removal of the adrenal gland). Some studies have shown that the severity of hypercortisolism, as well as the degree of HPA axis suppression and treatment with ketoconazole pre-surgery in CS patients, are associated with a longer duration of PSH. Until now, however, there have been only a few studies to guide in predicting the occurrence and duration of PSH. Therefore, researchers conducted a study to determine whether HPA axis activity, determined by levels of ACTH and cortisol, could predict the occurrence and duration of PSH in patients who undergo an adrenalectomy. Researchers studied 80 patients who underwent adrenalectomy for either CS or AI. Prior to the surgery, researchers measured levels of ACTH, urinary free cortisol (UFC), and serum cortisol after 1 mg dexamethasone suppression test (1 mg-DST). After the surgery, all patients were placed on steroid replacement therapy and PSH was determined after two months. For those with PSH, levels of cortisol were determined every six months for at least four years. Results showed that PSH occurred in 82.4 percent of CS patients and 46 percent of AI patients. PSH lasted for longer than 18 months in 50 percent of CS and 30 percent of AI patients. Furthermore, it lasted longer than 36 months for 35.7 percent of CS patients. In all patients, PSH was predicted by pre-surgery cortisol levels after the 1 mg-DST, but with less than 70 percent accuracy. In AI patients, a shorter-than-12-month duration of PSH was not predicted by any HPA parameter, but was significantly predicted by an absence of pre-surgery diagnosis of subclinical hypercortisolism. So, this study did not find any parameters that could significantly predict with high sensitivity and specificity the development or duration of PSH in all patients undergoing adrenalectomy. Consequently, the authors concluded that “the PSH occurrence and its duration are hardly predictable before surgery. All patients undergoing unilateral adrenalectomy should receive a steroid substitutive therapy.” From https://cushieblog.com/2017/12/14/patients-undergoing-adrenalectomy-should-receive-steroid-substitutive-therapy/