Lipid Abnormalities in Patients With Cushing's Disease and Its Relationship With Impaired Glucose Metabolism

Metyrapone Treatment Protects Low-Density Lipoprotein Receptor Knockout Mice against Hypercorticosteronemia Development without Changing Atherosclerosis Susceptibility

The steroid 11beta-hydroxylase inhibitor metyrapone is able to effectively reverse the hypercortisolemia detected in human Cushing's Syndrome patients. In this current preclinical study, we investigated whether metyrapone monotherapy can also reverse the hypercortisolemia-associated increase in atherosclerotic cardiovascular disease risk. In this instance, female low-density lipoprotein receptor knockout mice fed a cholic acid-containing high cholesterol/high fat diet to induce the development of hypercorticosteronemia and atherosclerotic lesions were treated twice daily with 100 mg/kg metyrapone for 4 weeks. Metyrapone effectively protected against hypercorticosteronemia development with endpoint plasma corticosterone levels remaining 43% lower than in controls (p < 0.01). Gene expression analysis in livers and adrenals validated that glucocorticoid receptor signaling was also reduced. Importantly, metyrapone treatment did not impact plasma cholesterol levels or alter atherosclerotic plaque areas or lesional collagen contents. However, metyrapone induced significant systemic lymphocytopenia as evident from marked decreases in splenic white pulp contents and thymus weights (-48% and -41%, respectively; p < 0.001). In conclusion, we have shown that treatment with metyrapone diminishes hypercorticosteronemia without affecting atherosclerosis susceptibility in cholic acid-containing high cholesterol/high fat diet-fed low-density lipoprotein receptor knockout mice. These preclinical findings highlight that restoring plasma glucocorticoid levels to normal is not necessarily sufficient to overcome the cardiovascular co-morbidities associated with human Cushing's disease.

Clinical Biology of the Pituitary Adenoma

All endocrine glands are susceptible to neoplastic growth, yet the health consequences of these neoplasms differ between endocrine tissues. Pituitary neoplasms are highly prevalent and overwhelmingly benign, exhibiting a spectrum of diverse behaviors and impact on health. To understand the clinical biology of these common yet often innocuous neoplasms, we review pituitary physiology and adenoma epidemiology, pathophysiology, behavior, and clinical consequences. The anterior pituitary develops in response to a range of complex brain signals integrating with intrinsic ectodermal cell transcriptional events that together determine gland growth, cell type differentiation, and hormonal production, in turn maintaining optimal endocrine health. Pituitary adenomas occur in 10% of the population; however, the overwhelming majority remain harmless during life. Triggered by somatic or germline mutations, disease-causing adenomas manifest pathogenic mechanisms that disrupt intrapituitary signaling to promote benign cell proliferation associated with chromosomal instability. Cellular senescence acts as a mechanistic buffer protecting against malignant transformation, an extremely rare event. It is estimated that fewer than one-thousandth of all pituitary adenomas cause clinically significant disease. Adenomas variably and adversely affect morbidity and mortality depending on cell type, hormone secretory activity, and growth behavior. For most clinically apparent adenomas, multimodal therapy controlling hormone secretion and adenoma growth lead to improved quality of life and normalized mortality. The clinical biology of pituitary adenomas, and particularly their benign nature, stands in marked contrast to other tumors of the endocrine system, such as thyroid and neuroendocrine tumors.

Ketogenic Diet Initially Masks Symptoms of Hypercortisolism in Cushing's Disease

Cushing’s syndrome (CS) is a diagnosis used to describe multiple causes of serum hypercortisolism. Cushing’s disease (CD), the most common endogenous subtype of CS, is characterized by hypercortisolism due to a pituitary tumor secreting adrenocorticotropic hormone (ACTH). A variety of tests are used to diagnose and differentiate between CD and CS. Hypercortisolism has been found to cause many metabolic abnormalities including hypertension, hyperlipidemia, impaired glucose tolerance, and central adiposity. Literature shows that many of the symptoms of hypercortisolism can improve with a low carb (LC) diet, which consists of consuming <30 g of total carbohydrates per day. Here, we describe the case of a patient with CD who presented with obesity, hypertension, striae and bruising, who initially improved some of his symptoms by implementing a LC diet. Ultimately, as his symptoms persisted, a diagnosis of CD was made. It is imperative that practitioners realize that diseases typically associated with poor lifestyle choices, like obesity and hypertension, can often have alternative causes. The goal of this case report is to provide insight on the efficacy of nutrition, specifically a LC diet, on reducing metabolic derangements associated with CD. Additionally, we will discuss the importance of maintaining a high index of suspicion for CD, especially in those with resistant hypertension, obesity and pre-diabetes/diabetes.

Hypertriglyceridemia and Other Plasma Lipid Profile Abnormalities among People Living with Diabetes Mellitus in Ethiopia: A Systematic Review and Meta-Analysis

Background

Dyslipidemia is one of the leading causes of cardiovascular complications in diabetes mellitus (DM) patients. Though it is a major public health problem in Ethiopia, there is no a nation-wide study to determine dyslipidemia among DM patients yet. Therefore, this systematic review and meta-analysis intended to estimate the prevalence of hypertriglyceridemia and other plasma lipid abnormalities among people living with DM in Ethiopia.

Methods

We systematically searched PubMed, Google Scholar, African Journals Online, Hinari, and direct Google. Studies conducted until May 9, 2020, that reports the prevalence of dyslipidemia among people living with DM were included. The DerSimonian and Laird random-effects model was used to determine the pooled prevalence of lipid profile abnormalities. Heterogeneity was checked using the I ² statistic, whereas publication bias was tested by funnel plot and Egger's test. Besides, subgroup and sensitivity analyses were performed.

Results

We used 18 primary studies, including 4961 participants living with DM, which met the eligibility criteria for the meta-analysis of hypertriglyceridemia. The estimate of hypertriglyceridemia (≥150 mg/dl) was 48.15% (95% CI: 38.15-58.15, I ² = 98.4%) after performing the main meta-analysis using the random-effects model. The subgroup analysis showed a higher pooled estimate of hypertriglyceridemia among T2DM (57.80% (95% CI: 50.50-65.10), I ² = 92.5%), studies that used probability sampling technique (59.09% (95% CI: 43.58-74.59), I ² = 98.6%, p < 0.001), and studies from primary data sources (51.43% (95% CI: 40.72-62.13), I ² = 98.0%, p < 0.001). Moreover, the estimated pooled prevalence of the total plasma cholesterol (TC ≥ 200 mg/dl) was 34.08% (95% CI: 28.41-39.75, I ² = 92.4%), LDL - C ≥ 100 mg/dl was 41.13% (95% CI: 27.15-55.11, I² = 98.8%), and HDL ≤ 40 mg/dl for men and ≤ 50 mg/dl for women was 44.36% (95% CI: 31.82-56.90, I ² = 98.8%).

Conclusions

The pooled prevalence of hypertriglyceridemia and other lipid abnormalities among DM patients was relatively high in Ethiopia. It strongly suggests the need to give maximal attention to the adherence of DM management to reduce the circulatory lipid profile abnormalities and subsequent complications. Prospero Registration. CRD42020182291.