Hypopituitarism in the elderly: a narrative review on clinical management of hypothalamic-pituitary-gonadal, hypothalamic-pituitary-thyroid and hypothalamic-pituitary-adrenal axes dysfunction

Diagnosis and therapeutic approach to bone health in patients with hypopituitarism

The results of many studies in recent years indicate a significant impact of pituitary function on bone health. The proper function of the pituitary gland has a significant impact on the growth of the skeleton and the appearance of sexual dimorphism. It is also responsible for achieving peak bone mass, which protects against the development of osteoporosis and fractures later in life. It is also liable for the proper remodeling of the skeleton, which is a physiological mechanism managing the proper mechanical resistance of bones and the possibility of its regeneration after injuries. Pituitary diseases causing hypofunction and deficiency of tropic hormones, and thus deficiency of key hormones of effector organs, have a negative impact on the skeleton, resulting in reduced bone mass and susceptibility to pathological fractures. The early appearance of pituitary dysfunction, i.e. in the pre-pubertal period, is responsible for failure to achieve peak bone mass, and thus the risk of developing osteoporosis in later years. This argues for the need for a thorough assessment of patients with hypopituitarism, not only in terms of metabolic disorders, but also in terms of bone disorders. Early and properly performed treatment may prevent patients from developing the bone complications that are so common in this pathology. The aim of this review is to discuss the physiological, pathophysiological, and clinical insights of bone involvement in pituitary disease.

Treating Hypopituitarism in the Over 65s: Review of Clinical Studies

The current increase of life expectancy is associated with the presence of endocrine diseases in the elderly. The management of hypopituitarism in this group of patients is a challenging task. A correct diagnosis, which represents an essential requisite for an appropriate medical treatment, can be difficult because of the physiological changes occurring in pituitary function with aging, which may lead to challenges in the interpretation of laboratory results. Furthermore, the treatment requires several careful considerations: the need to restore the hormonal physiology with replacement therapies must be balanced with the need to avoid the risks of the over-replacement, especially in the presence of concomitant cardiovascular and metabolic disease. Interactions with other drugs able to modify the absorption and/or the metabolism of hormonal replacement therapies should be considered, in particular for the treatment of hypoadrenalism and hypothyroidism. The most important challenges stem from the lack of specific studies focused on the management of hypopituitarism in older people.

Acute Secondary Adrenal Insufficiency Misdiagnosed as Acute Cholecystitis

Hypopituitarism refers to insufficient secretion of the pituitary hormones. Patients with acute adrenocorticotropic hormone (ACTH) deficiency may be presented with fatigue, dizziness, orthostatic hypotension, hypoglycemia, nausea, vomiting, or nonspecific abdominal pain. This study described an unusual case of hypopituitarism in a patient who presented with general abdominal pain, abdominal tenderness, nausea, vomiting, hypotension, and hypoglycemia. At first, the patient was admitted with the diagnosis of acute cholecystitis, but after treatment of hypopituitarism and adrenal insufficiency, his symptoms resolved completely, without the need for surgery. Hypopituitarism and secondary adrenal insufficiency should be considered in the differential diagnosis of the patients who present with acute abdomen, hypotension, or hypoglycemia.

Activation of Age-Related Nuclear Factor-κB Signaling Pathway Leads to Chronic Inflammation and Pituitary Fibrosis

OBJECTIVE

The purpose of the present study was to investigate the mechanism of pituitary fibrosis in elderly people.

METHODS

First, 20 pituitary glands obtained from 11 elderly people and 9 young people were studied using Masson's trichrome staining for fibrosis detection. Second, pituitary glands from 12 male rats, including 6 aged rats (OM group) and 6 young rats (YM group), were also studied. Western blotting was performed to detect collagen 1 and phosphorylation of the nuclear factor (NF)-κB subunit p65 in the OM and YM groups. The levels of 8 proinflammatory cytokines (interleukin [IL]-1α, IL-1β, IL-2, IL-4, IL-6, IL-8, interferon-γ, and tumor necrosis factor-α) in the rat pituitary glands were detected using liquid suspension chip technology. Enzyme-linked immunosorbent assays were performed to detect the growth hormone (GH) levels in the venous blood samples from the rats. Next, 12 aged rats were randomly divided into 2 groups: the QNZ (Q)+OM and normal physiological saline (N)+OM groups. The Q+OM and N+OM groups had undergone intervention by intraperitoneally injection of QNZ and physiological saline (1 mg/kg) for 28 days, respectively. Finally, biochemical and histological examinations were performed, including Masson's trichrome staining for fibrosis, Western blotting for phosphorylation of p65, Millipore multiplex bead arrays (Millipore, Billerica, Massachusetts, USA) for proinflammatory cytokine levels, and enzyme-linked immunosorbent assays for GH secretion.

RESULTS

Fibrosis was detected in the elderly patient group. Collagen 1, phosphorylation of the NF-κB signaling pathway, and the proinflammatory cytokine levels showed a significant increase in the OM group. Compared with the N+OM group, pituitary fibrosis was alleviated in the Q+OM group, with an increase in GH secretion and decreased proinflammatory cytokine levels and NF-κB.

CONCLUSIONS

Pituitary fibrosis was found in the elderly group, and the pathological change was antagonized by decreasing the proinflammatory cytokine levels using QNZ and further increasing GH secretion.

Untargeted LC/MS-Based Metabolic Phenotyping of Hypopituitarism in Young Males

Objective: Hypopituitarism (Hypo-Pit) is partial or complete insufficiency of anterior pituitary hormones. Besides hormone metabolism, the global metabolomics in Hypo-Pit are largely unknown. We aimed to explore potential biomarkers to aid in diagnosis and personalized treatment.

Methods: Using both univariate and multivariate statistical methods, we identified 72 differentially abundant features through liquid chromatography coupled to high-resolution mass spectrometry, obtained in 134 males with Hypo-Pit and 90 age matched healthy controls.

Results: Hypopituitarism exhibits an increased abundance of metabolites involved in amino acid degradation and glycerophospholipid synthesis, but decreased content of metabolites in steroid hormone synthesis and fatty acid beta-oxidation. Significantly changed metabolites included creatine, creatinine, L-alanine, phosphocholines, androstenedione, hydroprenenolone, and acylcarnitines. In Hypo-Pit patients, the increased ratio of creatine/creatinine suggested reduced creatine uptake and impaired creatine utilization, whereas the decreased level of beta-hydroxybutyrate, acetylcarnitine (C2) and a significantly decreased ratio of decanoylcarnitine (C10) to free carnitine suggested an impaired beta-oxidation. Furthermore, the creatine/creatinine and decanoylcarnitine/carnitine ratio were identified as diagnostic biomarkers for Hypo-Pit with AUCs of 0.976 and 0.988, respectively. Finally, we found that the creatinine and decanoylcarnitine/carnitine ratio could distinguish cases that were sensitive vs. resistant to human chorionic gonadotropin therapy.

Conclusion: We provided a global picture of altered metabolic pathways in Hypo-Pit, and the identified biomarkers in creatine metabolism and beta-oxidation might be useful for the preliminary screening and diagnosis of Hypo-Pit.

Classic cardiovascular risk factors improve in very elderly hypopituitary patients treated on standard hormone replacement in long term follow- up

Background

Hypopituitarism in the elderly population is an underdiagnosed condition and may increase comorbidities related to glucose metabolism, dyslipidemia, and cardiovascular risk factors. Optimization of hormone replacement that considers alterations in clearance rates of hormones, interaction with other medications, and evaluation of the risk-benefit ratio of treatment is a big challenge for clinical practice.

Objectives

This study aimed to evaluate classic cardiovascular risk factors in hypopituitary septuagenarians and octagenarians by diagnosis and after long-term hormone replacement.

Methods

This is a retrospective observational study, with patients recruited and selected from a registry in a tertiary medical center. We included patients aged 70–99 years with hypopituitarism, evaluated hormonal and biochemical parameters, and cardiovascular risk scores were calculated by diagnosis and compared after long-term follow-up. All patients gave informed consent. Patient data were compared to a sex and age-matched control group, with long-term geriatric follow-up, without endocrine diseases.

Results

Thirty-five patients were included, 16 patients aged 70–75 years (72.61), 12 patients 76–80 years (72.28), 7 patients 81–99 years (89.28). Pituitary macroadenomas were the main cause of hypopituitarism, mean maximal diameter 3.4 cm (2.9–4.3), and invasive craniopharyngiomas. At the moment of diagnosis, most patients were overweight, and abdominal adiposity was observed in 76.9% of women and 36.4% of men, primarily in octagenarians and nonagenarians. Comorbidities were frequent; 85.7% presented hypertension, 37.1% diabetes, 53.1% low HDL, 51.5% hypertriglyceridemia. Most patients presented more than two combined pituitary deficiencies; hypogonadism in 88.6%, central hypothyroidism in 82.9%, GH deficiency in 65.7%, and adrenal insufficiency in 25.7%. Analysis of cardiovascular risk prediction in the total cohort showed that 57.1% of patients presented a reduction in the General Cardiovascular Disease (CVD) Risk Prediction Score and 45.7% in atherosclerotic CVD risk estimated by ACC/AHA 2013 Pooled Cohort Equation, despite being submitted to conventional hormone replacement, during the mean follow-up of 14.5 years. This reduction was not observed in the control group.

Discussion and conclusion

In this study, aged hypopituitary patients presented a reduction in estimated general CVD risk during long-term follow-up, despite replacement with corticosteroids, levothyroxine, or gonadal steroids. Early diagnosis and treatment of hypopituitarism in the elderly remain challenging. Larger studies should be performed to assess the risk-benefit ratio of hormone replacement on the metabolic profile in septuagenarian and octogenarian patients.

Pituitary macroadenoma presenting as severe hyponatremia: a case report

Background

Hyponatremia is defined as a serum sodium level of less than 135 mEq/L in a patient. Although hyponatremia is not an uncommon laboratory finding, especially in the elderly, hunting for the etiology is a challenging issue for any clinician. The three first-line investigations that are required for further analysis are urine osmolality, serum osmolality, and urinary sodium levels in addition to clinical assessment of volume status.

Case presentation

A 69-year-old previously well Sinhalese man presented with lethargy, loss of appetite, vomiting, and altered behavior of 1 week’s duration. An examination revealed Glasgow Coma Scale of 13/15 and marginally low blood pressure. Initial serum sodium level was 104 mmol/L, and plasma and urinary osmolalities were 251 mOsm/kg and 305 mOsm/kg, respectively. His urinary sodium level of 158 mmol/L was suggestive of a clinical picture of a syndrome of inappropriate secretion of antidiuretic hormone. Even after correction of hyponatremia with intravenously administered 3% saline, a persistent altered behavior necessitated cerebral imaging that confirmed the presence of pituitary macroadenoma. Meanwhile, his hormone profile showed very low serum cortisol and low free tetraiodothyronine levels. An ultrasound scan of his abdomen affirmed the presence of normal adrenal glands. With intravenously administered hydrocortisone and orally administered levothyroxine replacement, he showed marked clinical improvement that supported the diagnosis of hypopituitarism.

Conclusion

Hyponatremia in the elderly is not an uncommon presentation. However, etiological diagnosis is a challenging task as there are multiple overlapping differential diagnoses.

Hypothalamic hypopituitarism secondary to suprasellar metastases from small cell lung cancer: a case report and review of the literature

Background

Metastasis to the pituitary gland is an infrequent clinical problem, and the symptoms caused by metastases have been reported in only 2.5–18.2% of the cases. However, metastasis to the suprasellar lesion has rarely been reported in the literature. To the best of our knowledge, only nine cases of hypothalamic hypopituitarism due to metastases of solid tumors have been reported in English-language journals.

Case presentation

A 67-year-old Japanese man presented to our hospital with generalized weakness, lethargy, and weight loss. Laboratory data showed hypoglycemia together with low thyroid-stimulating hormone and free thyroxine. We suspected hypopituitarism and performed imaging of the head, which revealed multiple tumors, one of which was in the suprasellar region. Computed tomography of the chest showed a tumor shadow, and a bronchoscopic biopsy pathologically showed small cell lung cancer. Hormone profiling demonstrated hypothalamic pan-hypopituitarism. We diagnosed hypothalamic hypopituitarism secondary to metastases from the primary lung cancer and initiated radiation, chemotherapy, and hormone replacement, but the patient died 10 months later.

Conclusions

We report a case of a 67-year-old man with hypothalamic hypopituitarism secondary to a suprasellar metastasis from a primary small cell lung cancer, and we review ten cases of hypothalamic hypopituitarism due to metastases, including our patient. Recognizing hypopituitarism can be challenging, especially in the elderly, whose symptoms such as lethargy and visual decline may be mistaken for the natural aging process. In patients with established metastatic conditions, the symptoms may be wrongly attributed to malignancy or to the side effects of therapy. When a patient is suspected of having hypopituitarism, a hormone load test can help to diagnose the type of hypopituitarism. It is important to evaluate the brain and the whole body to confirm whether metastasis and primary cancer exist. Because the mortality rate is very high, aggressive intervention for both diagnosis and therapy is required in cases of hypothalamic hypopituitarism secondary to tumor metastasis.

Effect of hypothyroidism on the hypothalamic-pituitary-ovarian axis and reproductive function of pregnant rats

BACKGROUND

This study aimed to detect changes in hormone levels in the hypothalamic-pituitary-ovarian axis in Sprague-Dawley (SD) rats with hypothyroidism, and identify differences in the pregnancy and abortion rates of female adult rats. The potential role of gonadotropin releasing hormone (GnRH) as the link between the hypothalamic-pituitary-ovarian axis and reproductive function regulated by thyroid hormones was also investigated.

METHODS

Female SD rats (n = 136) were causally classified into two groups: the normal-drinking-water group (n = 60) and the 0.05% propylthiouracil-drinking-water group (PTU 2 mg/kg/day, n = 76) to establish an adult rat model of hypothyroidism (6 weeks). Female and male rats at a ratio of 1:2 were used to establish a hypothyroidism pregnancy model. GnRH mRNA and GnRH receptor (GnRHR) expression in rats was detected using real time quantitative PCR(qRT-PCR) and immunohistochemistry, respectively.

RESULTS

The abortion rate differed significantly between the hypothyroidism pregnancy group and the normal pregnancy group (P < 0.05). No significant differences were found in the distribution of the GnRHR among the five nuclei (hypothalamic arcuate nucleus, hypothalamic ventromedial nucleus, hypothalamic anterior nucleus, paraventricular nucleus of the hypothalamus, and ventral premammillary nucleus) of the hypothalamus and ovary (P > 0.05). Hypothyroidism had no significant effect on GnRH mRNA expression in the hypothalamic-pituitary-ovarian axis in the four groups (normal control group, normal pregnancy group, hypothyroidism pregnancy group, and hypothyroidism group) (P > 0.05).

CONCLUSIONS

Hypothyroidism had an adverse impact on pregnancy in rats and may affect the distribution of pituitary GnRHR, whereas it did not obviously affect the distribution of GnRHR in the nuclei of the hypothalamus and ovary. Hypothyroidism had no effect on GnRH mRNA expression.

Mouse Thyroid Gland Changes in Aging: Implication of Galectin-3 and Sphingomyelinase

Prevalence of thyroid dysfunction and its impact on cognition in older people has been demonstrated, but many points remain unclarified. In order to study the effect of aging on the thyroid gland, we compared the thyroid gland of very old mice with that of younger ones. We have first investigated the changes of thyroid microstructure and the possibility that molecules involved in thyroid function might be associated with structural changes. Results from this study indicate changes in the height of the thyrocytes and in the amplitude of interfollicular spaces, anomalous expression/localization of thyrotropin, thyrotropin receptor, and thyroglobulin aging. Thyrotropin and thyrotropin receptor are upregulated and are distributed inside the colloid while thyroglobulin fills the interfollicular spaces. In an approach aimed at defining the behavior of molecules that change in different physiopathological conditions of thyroid, such as galectin-3 and sphingomyelinase, we then wondered what was their behavior in the thyroid gland in aging. Importantly, in comparison with the thyroid of young animals, we have found a higher expression of galectin-3 and a delocalization of neutral sphingomyelinase in the thyroid of old animals. A possible relationship between galectin-3, neutral sphingomyelinase, and aging has been discussed.