Two years of growth hormone replacement therapy in a group of patients with Sheehan's syndrome

High prevalence of coronary artery calcification and increased risk for coronary artery disease in patients with Sheehan syndrome-A case-control study

OBJECTIVE

Patients with Sheehan syndrome (SS) are predisposed to coronary artery disease (CAD) due to risk factors like abdominal obesity, dyslipidemia and chronic inflammation. In addition to estimate CAD risk enhancers like high sensitive C reactive protein (hsCRP), apolipoprotein B (ApoB) and lipoprotein A [Lp(a)], this study applies Framingham risk score (FRS) and coronary artery calcium (CAC) score to compute a 10-year probability of cardiovascular (CV) events in SS patients.

DESIGN

Case-control study Sixty-three SS patients, on a stable hormonal replacement treatment except for growth hormone and 65 age, body mass index and parity-matched controls.

MEASUREMENTS

Measurement of serum hsCRP, ApoB and Lp(a) and estimation of CAC with 16-row multislice computed tomography scanner.

RESULTS

The concentrations of hsCRP, ApoB and Lp(a) were significantly higher in SS patients than in controls (p < .01). After calculating FRS, 95.2% of SS patients were classified as low risk, 4.8% as intermediate risk and all controls were classified as low risk for probable CV events. CAC was detected in 50.7% SS patients and 7.6% controls (p = .006). According to the CAC score, 26.9% SS patients were classified as at risk (CAC > 10) for incident CV events as against 1.6% controls. The mean Multi-Ethnic Study of Atherosclerosis (MESA) score was significantly higher in patients with SS than controls. CAC corelated significantly with fasting blood glucose (r = .316), ApoB (r = .549), LP(a) (r = .310) and FRS (r = .294).

CONCLUSION

Significant number of asymptomatic SS patients have high coronary artery calcium score and are classified at risk for CAD.

Sheehan syndrome: Cardiovascular and metabolic comorbidities

Sheehan syndrome (SS) caused by postpartum hemorrhage leads to partial or complete pituitary hormone deficiency. In addition to lipid and glucose abnormalities, patients with SS have increased body fat, insulin resistance (IR), coagulation abnormalities, increased leptin concentration, low-grade inflammation, and endothelial dysfunction that predispose them to cardiovascular diseases. Untreated growth hormone (GH) deficiency, hypogonadism, and excess glucocorticoid use are considered risk factors for these abnormalities. Compared to other hypopituitary subjects, patients with SS are younger and have a longer duration of disease and severe GH deficiency. Replacement with GH in addition to standard hormone replacement improves their cardiometabolic profile.

Sheehan syndrome

Sheehan syndrome or postpartum hypopituitarism is a condition characterized by hypopituitarism due to necrosis of the pituitary gland. The initial insult is caused by massive postpartum haemorrhage (PPH), leading to impaired blood supply to the pituitary gland, which has become enlarged during pregnancy. Small sella turcica size, vasospasms (caused by PPH) and/or thrombosis (associated with pregnancy or coagulation disorders) are predisposing factors; autoimmunity might be involved in the progressive worsening of pituitary functions. Symptoms are caused by a decrease or absence of one or more of the pituitary hormones, and vary, among others, from failure to lactate and nonspecific symptoms (such as fatigue) to severe adrenal crisis. In accordance with the location of hormone-secreting cells relative to the vasculature, the secretion of growth hormone and prolactin is most commonly affected, followed by follicle-stimulating hormone and luteinizing hormone; severe necrosis of the pituitary gland also affects the secretion of thyroid-stimulating hormone and adrenocorticotropic hormone. Symptoms usually become evident years after delivery, but can, in rare cases, develop acutely. The incidence of Sheehan syndrome depends, to a large extent, on the occurrence and management of PPH. Sheehan syndrome is an important cause of hypopituitarism in developing countries, but has become rare in developed countries. Diagnosis is based on clinical manifestations combined with a history of severe PPH; hormone levels and/or stimulation tests can confirm clinical suspicion. Hormone replacement therapy is the only available management option so far.

Pituitary disorders in pregnancy

The pituitary gland is significantly affected during gestation in terms of both size and function. Due to this physiologic adaptation, endocrine evaluation and interpretation of imaging is far more complex than in the non-pregnant state. Pituitary disorders are rare in pregnancy, as they are usually associated with gonadal dysfunction, thereby posing difficulties with fertility. This review will focus on pituitary adenomas (prolactinomas, GH-secreting and ACTH-secreting), their diagnostic handicaps and the recommendations for treatment. We will also discuss the two pituitary disorders encountered in pregnancy, Sheehan's syndrome and lymphocytic hypophysitis.

Estrogen suppresses adipogenesis by inhibiting S100A16 expression

The aim of this study is to determine the effects of E2 on metabolic syndrome and the molecular mechanisms involving S100A16. Ovariectomized (OVX) rat models and mouse embryonic fibroblasts cell models were used. E2 loss in OVX rats induced body weight gain and central abdominal fat accumulation, which were ameliorated by E2 treatment under chow and high-fat diet (HFD) conditions. E2 decreased the expression of the adipocyte marker genes PPARγ, aP2, C/EBPα, and S100A16. E2 inhibited adipogenesis. Overexpression of S100A16 reversed the E2-induced adipogenesis effect. A luciferase assay showed that E2 inhibited the expression of S100A16. E2 treatment decreased body weight gain and central abdominal fat accumulation under both chow and HFD conditions. Also, E2 suppressed adipogenesis by inhibiting S100A16 expression.

Sheehan's syndrome with reversible dilated cardiomyopathy: A case report and brief overview

Sheehan's syndrome is a rare condition characterized by post-partal panhypopituitarism due to necrosis of adenohypophysis resulting from severe post-partum hemorrhage. Lethargy, amenorrhea and failure of lactation are the usual presenting features. Cardiac involvement in Sheehan's syndrome is rare. The case presented here describes dilated cardiomyopathy in a 36-year-old lady who failed to respond adequately to the standard anti-failure treatment. Further investigation revealed the diagnosis of Sheehan's syndrome. Besides other manifestations, cardiac function reverted to normal after giving replacement therapy with glucocorticoid, levothyroxine and sex hormone. Physicians, specially those in developing countries, should have high index of suspicion for the diagnosis of Sheehan's syndrome while dealing with a case of 'peripartal dilated cardiomyopathy'. Persistent amenorrhea and failure of lactation may be important clues in this context. Timely diagnosis and appropriate treatment can lessen the sufferings of the patients.

Pregnancy and other pituitary disorders (including GH deficiency)

The pituitary gland is one of the most affected organs with altered anatomy and physiology during pregnancy. Acromegaly is the second most common pituitary adenoma seen in relation to gestation after prolactinomas. Acromegaly should be treated before conception to prevent potential tumor growth in patients who desire fertility. Medical therapy can be ceased safely after confirmation of pregnancy in acromegalic patients, but octreotide may be used in selected cases with compressive signs. Other hormonal and non-functional tumors are rarer and have been presented as case reports. Sheehan's syndrome, which is one of the most common causes of hypopituitarism in developing countries, and lymphocytic hypophysitis are known to be associated with pregnancy. They usually result in hypopituitarism, sometimes with delays in diagnosis and difficulties in differential diagnosis. Pregnancy is not common among patients with hypopituitarism or pituitary adenomas due to altered gonadotroph functions. Ovulation induction is essential for fertility achievement, but the replacement of other deficient pituitary hormones, including GH, seems to play an important role in the preparation of the uterus for implantation of the embryo.

[Clinical, laboratory and therapeutics aspects of Sheehan's syndrome]

Sheehan's syndrome is characterized by hypopituitarism that occurs as a result of ischemic pituitary necrosis due to severe postpartum hemorrhage. Nowadays it is not usually seen in developed countries because of the improvements in obstetric care. However, in developing countries it is still frequent and probably one of the most common causes of hypopituitarism. Most patients usually present it months to years later, with a history of failure of postpartum lactation, failure to resume menses and other signs of panhypopituitarism. In mild forms of the disease, patients may remain undetected and do not receive treatment for many years. Early diagnosis and appropriate treatment are important to reduce the morbimortality of the patients with Sheehan's syndrome. The aim of this review is to describe clinical, laboratory and therapeutic aspects of Sheehan's syndrome, including our experience in the replacement of recombinant GH in these patients.