Predictive value of neuronal markers for pituitary dysfunction following traumatic brain injury: A preliminary study.

PURPOSE: Traumatic brain injury (TBI), a well-known risk factor for pituitary dysfunction, is associated with increased serum neurofilament light chain (NFL), glial fibrillary acidic protein (GFAP), and total tau (t-tau) levels. We aimed to assess the predictive value of these markers and pituitary dysfunction following TBI in a prospective manner. METHODS: Adult patients following TBI were included. Serum levels of NFL, GFAP, t-tau and pituitary and target hormones were analyzed prospectively during first week and one year after TBI. RESULTS: Twenty-two patients (17 males, 5 females; mean age 40±15 years) were included in the study. Basal NFL levels correlated positively with length of hospital stay and basal cortisol (r=0.643, p=0.001 and r=0.558, p=0.007, respectively) and negatively with Glasgow Coma Scale (GCS) score and basal IGF-1 levels (r=-0.429, p=0.046 and r=-0.481, p=0.023, respectively), while there was no significant correlation between GFAP, t-tau and hormone levels. NFL, GFAP, and t-tau levels significantly decreased, and none of the patients developed hormone deficiencies one year after TBI. No correlations were detected between basal markers and first year pituitary hormone levels. CONCLUSION: Serum NFL levels were correlated with hormonal changes during acute phase of TBI reflecting the physiological response to trauma. Larger studies are needed to analyze the associations during chronic phase.

Can salivary cortisol be used in diagnosing adrenal insufficiency during the acute and subacute phases of traumatic brain injury?

INTRODUCTION: The diagnosis of adrenal insufficiency (AI) related to traumatic brain injury (TBI) remains a challenge. We investigated the basal and low-dose adrenocorticotropic hormone (ACTH)-stimulated serum cortisol and salivary cortisol (SaC) levels and the diagnostic utility of SaC levels during 28 days following TBI. MATERIALS AND METHODS: Blood samples were collected for basal levels [sequentially from day 1 (D1) to D7 and on D28)] and for peak serum cortisol and SaC responses to the low-dose ACTH stimulation test (on D1, D7, and D28). After the patient enrollment period was completed, patients were retrospectively categorized as AI or AS (adrenal sufficiency) for each day separately, based on a basal serum cortisol cut-off level of 11 µg/dL, and data analysis was performed between the groups. RESULTS: Thirty-seven patients and 40 healthy controls were included. Median basal serum cortisol levels were higher in patients on D1 but were similar on other days. Median basal SaC levels were higher in patients on D1 and D2 but were similar on other days. Median peak serum cortisol and SaC levels were similar on D1 but were lower in patients on D7 and D28. Median basal SaC levels were higher in the AS group than in the AI group on all days. DISCUSSION AND CONCLUSIONS: When evaluating AI during the course of TBI, the cut-off for basal SaC levels is 0.5-0.6 µg/dL throughout the first week, except for 1.38 µg/dL on D2. SaC levels may serve as a surrogate marker for accurately reflecting circulating glucocorticoid activity.

Diagnosis of hypoprolactinemia.

Prolactin is a polypeptide hormone composed of 199 amino acids, synthesized by lactotroph cells. Its primary effects are on the mammary gland and gonadal axes, but it also influences different organs and systems, particularly metabolic functions. Current literature has mainly focused on the diagnosis, monitoring, and treatment of hyperprolactinemia. Due to the lack of a well-established effective treatment for hypoprolactinemia, it is not clinically emphasized. Therefore, data on its diagnosis is limited. Hypoprolactinemia has been associated with metabolic dysfunctions such as type 2 diabetes mellitus, fatty liver, dyslipidemia, fertility problems, sexual dysfunction, and increased cardiovascular disease. While often seen as a part of combined hormone deficiencies due to pituitary damage, isolated prolactin deficiency is rare. Hypoprolactinemia can serve as a marker for extensive pituitary gland damage and dysfunction.Low or undetectable serum prolactin levels and the absence of a sufficient prolactin peak in the thyrotropin-releasing hormone (TRH) stimulation test are considered diagnostic for hypoprolactinemia. Gender appears to influence both basal prolactin levels and TRH stimulation test responses. Basal prolactin levels of, at least, 5 ng/mL for males and 7 ng/mL for females can be used as cut-off levels for normal prolactin reserve. Minimum peak prolactin responses of 18 ng/mL for males and 41 ng/mL for females to TRH stimulation can exclude hypoprolactinemia. However, larger population studies across different age groups and sexes are needed to better define normal basal prolactin levels and prolactin responses to the TRH stimulation test.

The coexistence of newly diagnosed acromegaly with primary empty sella: More frequent than expected?

OBJECTIVE: We investigated the coexistence of newly diagnosed acromegaly with primary empty sella (ES), which is considered to be a rare association, and the impact of ES on the laboratory, radiological and prognostic status of acromegaly. DESIGN: Acromegaly patients diagnosed and followed-up between 2012 and 2021 were included. Empty sella was defined as the pituitary gland and adenoma filling <50% of the sella turcica on preoperative T1 magnetic resonance imaging (MRI). RESULTS: 102 acromegalic patients (45 male, 57 female, 45.5 ± 12.8 (range: 20-70 years) were included and data of a median 3 years (range: 0.5-9 years) were presented. ES was detected in 19 (18.6%) patients and 4 had complete and 15 had partial ES. Although not significant, adenoma size and residual adenoma on MRI on postoperative 3rd month, and disease remission at last control were lower in acromegaly with ES than in acromegaly without ES, while the rate of female gender and remission on postoperative 3rd month were higher. While preoperative serum prolactin and nadir GH responses to OGTT were significantly lower in patients with ES, there was no difference in terms of other pituitary hormones among both groups. CONCLUSION: The present study revealed the coexistence of newly diagnosed acromegaly with primary ES at a rate of nearly 20% which is more frequent than expected and this association is not rare. The presence of ES was not associated with any preoperative/postoperative pituitary hormone levels and remission status, except lower preoperative prolactin and nadir GH responses to OGTT.

Assessment of semaphorin 3A and semaphorin 7A levels in primary Sjogren's syndrome.

Sjogren's syndrome (SS) is a chronic autoimmune connective tissue disease. Varying rates of system involvements may be seen in the course of the disease. Semaphorins has multifunctions in several physiological and pathological processes such as immune system regulation. The association of Semaphorin 3A (Sema3A) and Semaphorin 7A (Sema7A), which are immune semaphorins, with autoimmune diseases is interesting for researchers. We aimed to compare serum Sema3A and Sema7A levels between primary SS and control subjects, and investigated Sema3A and Sema7A levels in disease subgroups and associated system involvements. 50 consecutive primary SS patients and 40 healthy subjects followed in the Rheumatology clinic of Cumhuriyet University Medical Faculty between 2017 and 2018 were included in the study. Inclusion criteria of patients were diagnosis of primary SS according to the 2016 ACR/EULAR classification criteria. Serum Sema3A and Sema7A levels were measured by commercial ELISA kit. Both groups were similar in terms of age, gender, and body mass index. Serum Sema3A and Sema7A levels were significantly lower in SS than in the controls (p = 0.001 and p = 0.005, respectively). Serum Sema3A levels were significantly lower in patients with renal involvement than in patients without (p = 0.03). Sema3A and Sema7A may play a role in the etiopathogenesis of SS and may be a potential serological marker for the diagnosis of SS and may be a target for treatment.

The effect of additional acarbose on metformin-associated artificially high 18F-Fluorodeoxyglucose uptake in positron emission tomography/computed tomography.

AIM: Metformin causes diffuse and intense fluorodeoxyglucose (FDG) uptake more frequently in the colon and less frequently in the small intestine. In this study, we aimed to investigate the effect of simultaneous use of acarbose and metformin on FDG uptake in positron emission tomography/computed tomography (PET/CT), which has not been investigated previously. METHODS: Totally 145 patients with a median age of 65 years (range: 18-80 years), who underwent FDG PET/CT in the Department of Nuclear Medicine of Erciyes University Medical School between 2018 and 2021, were involved in the study. The patients undergoing PET/CT were categorized as metformin plus acarbose users (group MA), metformin users (group M), and control subjects without diabetes (group C). The maximum and mean standard uptake values (SUVmax and SUVmean) of FDG uptake of the all intestine segments were measured separately. RESULTS: The number of participants in each group was 35, 51 and 59 in group MA, group M and group C, respectively. The FDG uptake of all intestine was significantly higher in group MA and group M than in group C. The FDG uptake of ascending, transverse, descending, and sigmoid colon was significantly lower in group MA than in group M. The FDG uptake of the small intestine was not different between group MA and group M. The FDG uptake of the rectum was lower in group MA than group M and it was significant for SUVmean, but not significant for SUVmax. CONCLUSION: The addition of acarbose to metformin therapy decreased SUV and artificially high FDG uptake in the colon and may be an alternative recommendation to discontinuing metformin in patients going to PET/CT imaging.

The potential impact of COVID-19 on thyroid gland volumes among COVID-19 survivors.

PURPOSE: Data about the effects of COVID-19 on the endocrine system are increasing over time. In the present study, we investigated the effects of COVID-19 on the thyroid gland among COVID-19 survivors by comparing them with healthy subjects. METHODS: Adult COVID-19 survivors who were managed and followed up in the Infectious Disease clinic were asked to participate in this study. COVID-19 survivors were recruited via a convenience sampling and those who agreed to participate in this study were seen by endocrinologists for assessments. The blood tests were obtained for thyroid antibodies and thyroid function tests. Thyroid ultrasonography (USG) was done by the same physician. The ellipsoid formula was used for the calculation of thyroid gland volume. RESULTS: 64 adult COVID-19 survivors and 70 control subjects were enrolled in the study. The COVID-19 survivors were evaluated at median 5.7 months (IQR: 4-6.5) (range: 2-7 months) after acute infection. The mean thyroid gland volume was significantly lower in COVID-19 survivors (10.3 ± 3.4 mL) than in the controls (14 ± 5.3 mL) (p = 0.001). There was no significant difference in free triiodothyronine (fT3), free thyroxine (fT4) and thyroid-stimulating hormone (TSH) levels between the groups. Among the twelve patients who had thyroid function evaluated in acute COVID-19, fT3 values were lower in acute COVID-19 than at the time of USG evaluation (3.04 ± 0.41 vs 3.47 ± 0.31 pg/mL), (p = 0.02). Among COVID-19 survivors, mild TSH elevation was detected in 4 (6.2%) patients and all of the other COVID-19 survivors (93.7%) were euthyroid. CONCLUSIONS: At 6 months after acute COVID, COVID-19 survivors had smaller thyroid gland volume than healthy controls, and only a few of the COVID-19 survivors had abnormal thyroid function.

Investigation of pituitary functions after acute coronavirus disease 2019.

Although coronavirus disease 2019 (COVID-19) mainly involves the lungs, it also affects many systems. The hypothalamic/pituitary axis is vulnerable to hypoxia, hypercoagulation, endothelial dysfunction and autoimmune changes induced by COVID-19 infection. Given that there is no extensive investigation on this issue, we investigated the pituitary functions three to seven months after acute COVID-19 infection. Forty-three patients after diagnosis of COVID-19 infection and 11 healthy volunteers were included in the study. In addition to the basal pituitary hormone levels, growth hormone (GH) and hypothalamo-pituitary adrenal (HPA) axes were evaluated by glucagon stimulation test (GST) and low-dose adrenocorticotropic hormone (ACTH) stimulation test, respectively. The peak cortisol responses to low-dose ACTH test were insufficient in seven (16.2%) patients. Twenty (46.5%) and four (9.3%) patients had inadequate GH and cortisol responses to GST, respectively. Serum insulin-like growth factor-1 (IGF-1) values were also lower than age and sex-matched references in four (9.3%) patients. The peak GH responses to GST were lower in the patient group when compared to the control group. Other abnormalities were mild thyroid-stimulating hormone elevation in four (9.3%) patients, mild prolactin elevation in two (4.6%) patients and central hypogonadism in four (9.3%) patients. Mean total testosterone values were lower in male patients when compared to male controls; however, the difference was not significant. These findings suggest that COVID-19 infection may affect pituitary functions, particularly the HPA and GH axes. These insufficiencies should be kept in mind in post-COVID follow-up. Long-term data are needed to determine whether these deficiencies are permanent or not.