Glucocorticoid replacement is associated with hypertriglyceridaemia, elevated glucose and higher non-HDL cholesterol and may diminish the association of HDL cholesterol with the -629C>A CETP promoter polymorphism in GH-receiving hypopituitary patients

LIPEMIA RETINALIS DURING CHEMOTHERAPY WITH ADJUNCTIVE GLUCOCORTICOID TREATMENT IN A PATIENT WITH COLON CARCINOMA

PURPOSE

The purpose of this report is to describe a case of lipemia retinalis due to decompensating hyperlipidemia that occurred during chemotherapy in a patient with metastatic colon carcinoma.

METHODS

Retrospective case report.

RESULTS

A 55-year-old non-insulin-dependent diabetic man with well-controlled hyperlipidemia presented himself with temporarily blurred vision in both eyes occurring during chemotherapy. He was found to have lipemia retinalis in his both eyes. Blood tests revealed elevated cholesterol and triglyceride levels exceeding 8,200 mg/dL. He received six cycles of FOLFIRI/bevacizumab and accompanying dexamethasone because of colon cancer with pulmonary metastases. Lipemia retinalis had resolved after a 6-week follow-up when chemotherapy was finished, and the patients' triglyceride and glucose levels decreased to normal values.

CONCLUSION

Lipemia retinalis associated with visual impairment may occur during chemotherapy under accompanying treatment with dexamethasone. Even if patients with hyperlipidemia are metabolically well-controlled with oral medication, treatment with dexamethasone can potentially lead to decompensation of hyperlipidemia causing secondary lipemia retinalis.

Factors impacting on the action of glucocorticoids in patients receiving glucocorticoid therapy

Glucocorticoids (GCs) are steroid hormones, which are essential for life. They are secreted by the adrenal cortex under the control of the hypothalamic-pituitary-adrenal (HPA) axis. Glucocorticoids are essential for the normal function of most organ systems and, in both, excess and deficiency can lead to significant adverse consequences. Adrenal insufficiency (AI) is a rare, life-threatening disorder characterized by insufficient production of corticosteroid hormones. Primary AI is defined by the inability of the adrenal cortex to produce sufficient amounts of glucocorticoids and/or mineralocorticoids despite normal or increased adrenocorticotropin hormone (ACTH). Secondary AI is adrenal hypofunction due to insufficient amount of ACTH produced by the pituitary gland. Conventional treatment of both primary and secondary adrenal insufficiencies involves lifelong glucocorticoid replacement therapy. The role of cortisol deficiency and the impact of hydrocortisone replacement on morbidity and mortality in this patient group are under increasing scrutiny. Established glucocorticoid replacement regimens do not completely mirror endogenous hormonal production, and their monitoring to ensure optimum therapy is hampered by the lack of reliable biomarkers of hormone sufficiency. A further confounding issue is the tissue-specific regulation of glucocorticoid through the two isozymes of 11β-hydroxysteroid dehydrogenase (11β-HSD) with research focusing on the role of this prereceptor regulation in the development of adverse metabolic features in patients. This review defines the factors influencing glucocorticoid action in patients with adrenal insufficiency receiving glucocorticoid therapy.

Downregulation of cholesteryl ester transfer protein by glucocorticoids: a randomised study on HDL

BACKGROUND

High density lipoprotein (HDL) cholesterol is not decreased in hypercortisolism despite high triglycerides, which may be ascribed to effects on the cholesteryl ester transfer protein (CETP) pathway. We explored if CETP mRNA expression is modulated by glucocorticoid treatment in vitro. Effects of doubling the hydrocortisone (HCT) replacement dose on plasma CETP activity, and HDL characteristics were tested in patients with secondary adrenal insufficiency.

MATERIALS AND METHODS

Human THP-1 macrophages were incubated with corticosterone in vitro in the presence or absence of a liver X receptor (LXR) agonist, followed by determination of CETP mRNA levels by quantitative real-time PCR. In addition, a randomised double-blind cross-over study was performed in 47 patients with secondary adrenal insufficiency (university medical setting; 10 weeks exposure to a higher HCT dose (0·4-0·6 mg/kg body weight) vs. 10 weeks of a lower HCT dose (0·2-0·3 mg/kg body weight).

RESULTS

Corticosterone dose dependently decreased CETP mRNA in THP-1 macrophages. Corticosterone also decreased CETP mRNA expression after LXR pretreatment. In patients, CETP activity decreased with doubling of the HCT dose (P = 0·049), coinciding with an increase in HDL cholesterol, apolipoprotein A-I and the HDL cholesterol/apolipoprotein A-I ratio (reflecting HDL size; P < 0·01 for each). The increase in the HDL cholesterol/apolipoprotein A-I ratio was correlated with the decrease in plasma CETP activity (r = -0·442, P = 0·002).

CONCLUSION

Glucocorticoids downregulate CETP gene expression in a human macrophage cell system. In line, a higher glucocorticoid replacement dose decreases plasma CETP activity in patients, thereby contributing to higher HDL cholesterol and an increase in estimated HDL size.

High-density lipoproteins and adrenal steroidogenesis: A population-based study

BACKGROUND

Cholesterol trafficked within plasma lipoproteins, in particular high-density lipoproteins (HDL), may represent an important source of cholesterol that is required for adrenal steroidogenesis. Based on a urinary gas chromatography method, compromised adrenal function has been suggested in men but not in women with (genetically determined) low plasma HDL-cholesterol (HDL-C).

OBJECTIVE

The objective of the article was to examine the extent to which glucocorticoid production relates to HDL-C in a population-based cohort.

METHODS

A total of 240 subjects (120 men and 120 women, aged 20-79 years) without relevant comorbidities were recruited from the general population. Glucocorticoid metabolites were measured by gas chromatography with tandem mass spectrometric detection in 24-hour urine collections to estimate total glucocorticoid production (TGP). Fasting plasma (apo)lipoproteins were assayed by routine methods.

RESULTS

TGP was not decreased but tended to be increased in subjects with low HDL-C (NCEP-ATPIII criteria; P = .094). In univariate analysis, TPG was correlated inversely with HDL-C (r = -0.353, P < .001) and apoA-I (r = -0.263, P = .01). Multivariable linear regression analysis demonstrated that TGP was still inversely related to HDL-C (β = -0.145, P = .019) or alternatively to low HDL-C (β = -0.129, P = .013) taking age, sex, current smoking, and other metabolic syndrome components into account.

CONCLUSION

In this population-based study, urinary glucocorticoid metabolite excretion was inversely associated with HDL-C. We found no evidence for an attenuated adrenal function in men and women with low HDL-C.

Adrenal cortical insufficiency--a life threatening illness with multiple etiologies

BACKGROUND

The clinical signs of adrenal cortical insufficiency (incidence, ca. 25 per million per year; prevalence, ca. 400 per million) are nonspecific, and misdiagnoses are therefore common. Glucocorticoid substitution therapy has been in use for 50 years but is not a wholly adequate treatment. Our understanding of this disease remains incomplete in many ways.

METHOD

We selectively searched the Medline database for publications on adrenal cortical insufficiency, with particular attention to studies from the year 2000 onward (search terms: "adrenal insufficiency" or "Addison's disease" or "hypopituitarism").

RESULTS

Hydrocortisone substitution therapy is often given in doses of 10-25 mg/day, timed according to the circadian rhythm. Gastrointestinal and other, febrile infections account for 30-50% of life-threatening adrenocortical crises. Such crises affect 8 of 100 persons with adrenal cortical insufficiency per year and must be treated by the immediate administration of glucocorticoids and fluids. When persons with adrenal cortical insufficiency are acutely ill or are otherwise under unusual stress, they may need additional amounts of hydrocortisone, often in the range of 5-10 mg but occasionally as high as 200 mg. The sustained administration of excessive amounts of steroid can shorten patients lives by several years. Inappropriate substitution therapy can cause other major medical conditions, such as metabolic syndrome and osteoporosis.

CONCLUSION

Important measures for the prevention of adrenocortical crises include improved care by treating physicians, education of patients and their families, the provision of emergency identifying documents, and the prescription of glucocorticoid emergency kits.

Effect of swimming on the production of aldosterone in rats

It has been demonstrated that exercise is one of the stresses known to increase the aldosterone secretion. Both potassium and angiotensin II (Ang II) levels are shown to be correlated with aldosterone production during exercise, but the mechanism is still unclear. In an in vivo study, male rats were catheterized via right jugular vein (RJV), and divided into four groups namely water immersion, swimming, lactate infusion (13 mg/kg/min) and pyruvate infusion (13 mg/kg/min) groups. Each group was treated for 10 min. Blood samples were collected at 0, 10, 15, 30, 60 and 120 min from RJV after administration. In an in vitro study, rat zona glomerulosa (ZG) cells were challenged by lactate (1–10 mM) in the presence or absence of Ang II (10⁻⁸ M) for 60 min. The levels of aldosterone in plasma and medium were measured by radioimmunoassay. Cell lysates were analyzed by immunoblotting assay. After exercise and lactate infusion, plasma levels of aldosterone and lactate were significantly higher than those in the control group. Swimming for 10 min significantly increased the plasma Ang II levels in male rats. Administration of lactate plus Ang II significantly increased aldosterone production and enhanced protein expression of steroidogenic acute regulatory protein (StAR) in ZG cells. These results demonstrated that acute exercise led to the increase of both aldosterone and Ang II secretion, which is associated with lactate action on ZG cells and might be dependent on the activity of renin-angiotensin system.

Glucocorticoid replacement therapy is independently associated with reduced bone mineral density in women with hypopituitarism

OBJECTIVE

Patients with hypopituitarism have adverse cardiovascular morbidity and reduced bone mineral density (BMD). The objective of this study was to analyse the effects of glucocorticoid (GC) replacement on cardiovascular risk factors and BMD in patients with hypopituitarism.

DESIGN, PATIENTS AND METHODS

This was a cross-sectional study on 365 patients with hypopituitarism. Two-hundred and four patients (56%) were ACTH insufficient (ACTHins), receiving a mean ± SD hydrocortisone equivalent (HCeq) dose of 20·5 ± 5·8 mg/day. The difference in BMD and cardiovascular risk profile between ACTH sufficient (ACTHsuff) and ACTHins patients, before commencement of GH replacement, was analysed by multiple linear and logistic regression.

RESULTS

ACTHins was independently associated with lower fasting glucose but not other cardiovascular risk factors. The mean HCeq dose per kg body weight was 15% higher in ACTHins women than in ACTHins men (P = 0·009). In women, ACTHins was independently associated with decreased BMD at the lumbar spine (P = 0·002) and femoral neck (P = 0·006) and the presence of osteopenia (P = 0·004). BMD was not different between ACTHins and ACTHsuff men.

CONCLUSION

The current average HCeq dose of approximately 20 mg per day is not associated with an adverse metabolic profile, as compared with ACTHsuff patients with hypopituitarism. GC replacement in ACTHins women is independently associated with reduced BMD and higher prevalence of osteopenia.

What is the best long-term management strategy for patients with primary adrenal insufficiency?

Primary adrenal insufficiency is treated with glucocorticoid and mineralocorticoid replacement therapy. Recent data revealed that health-related quality of life in adrenal insufficiency is impaired in many patients and that patients with adrenal insufficiency are also threatened by an increased mortality and morbidity. This may be caused by inadequate glucocortiocid therapy and adrenal crisis. Therefore, the optimization of hormone replacement therapy remains one of the most challenging tasks in endocrinology because it is largely based on clinical grounds because of the lack of objective assessment tools. This article provides answers to the important daily clinical questions, such as correct dose finding, dose adaptation in special situations, e g, pregnancy, improvement of quality of life and measures for protection from adrenal crisis. Other important aspects discussed are side effects of glucocortiocid replacement therapy and interactions with other drugs.

The pituitary gland and age-dependent regulation of body composition

CONTEXT

The prevalence of obesity is increased in hypopituitarism. In the general population, body mass index (BMI) and waist circumference increase with advancing age. It remains uncertain whether age-related changes in pituitary function contribute to the changes in body composition associated with advancing years.

OBJECTIVE

Our objective was to study the relationship between pituitary function, body composition, and age in a large cohort of patients with hypopituitarism and a matched reference population.

DESIGN, SETTING, AND PARTICIPANTS

A total of 3632 GH-deficient adults with hypopituitarism, adequately replaced with all pituitary hormones except for GH, from the prospective KIMS database (Pfizer International Metabolic Database) were included in present analysis. A random sample of the general population (3427 subjects) was used as reference. Patients and controls were grouped by gender in five age cohorts of 10 yr from 28 yr onward.

MAIN OUTCOME MEASURES

Differences in BMI and waist circumference were evaluated.

RESULTS

Patients had a significantly higher BMI and waist circumference than controls, with larger differences at younger age. With advancing age, an increase in BMI and waist circumference was seen in controls but was virtually absent in the patients with adult-onset GH deficiency and hypopituitarism.

CONCLUSION

Patients with hypopituitarism have more excess body fat than age-matched controls, especially in the youngest age groups. The normal increase in fat mass with advancing age is not seen in adult-onset GH-deficient hypopituitarism, suggesting a potential role for the normal pituitary gland as an age-dependent regulator of body composition in adult life.