Involvement of high density lipoprotein as substrate cholesterol for steroidogenesis by bovine adrenal fasciculo-reticularis cells

Low glucocorticoids in stress-related disorders: the role of inflammation

There is evidence that plasma cortisol concentration can be either increased or decreased in patients with depression and related anxiety and stress-related disorders; the exact pathophysiological mechanisms of this state are not almost clear. Several distinct theories were proposed and mechanisms, which could lead to decreased glucocorticoid signaling and/or levels, were described. However, there is a possible drawback in almost all the theories proposed: insufficient attention to the inflammatory process, which is undoubtedly present in several stress-related disorders, including post-traumatic stress disorder (PTSD). Previous studies only briefly mentioned the presence of an inflammatory reaction's signs in PTSD, without giving it due importance, although recognizing that it can affect the course of the disease. With that, the state of biochemical changes, characterized by the low glucocorticoids, glucocorticoid receptor's resistance and the signs of the persistent inflammation (with the high levels of circulating cytokines) might be observed not only in PTSD but in coronary heart diseases and systemic chronic inflammatory diseases (rheumatoid arthritis) as well. That is why the present review aims to depict the pathophysiological mechanisms, which lead to a decrease in glucocorticoids in PTSD due to the action of inflammatory stimuli. We described changes in the glucocorticoid system and inflammatory reaction as parts of an integral system, where glucocorticoids and the glucocorticoid receptor reside at the apex of a regulatory network that blocks several inflammatory pathways, while decreased glucocorticoid signaling and/or level leads to unchecked inflammatory reactions to promote pathologies such as PTSD. LAY SUMMARY This review emphasizes the importance of inflammatory reaction in the development of puzzling conditions sometimes observed in severe diseases including post-traumatic stress disorder - the decreased levels of glucocorticoids in the blood. Following the classical concepts, one would expect an increase in glucocorticoid hormones, since they are part of the feedback mechanism in the immune system, which reduces stress and inflammation. However, low levels of glucocorticoid hormones are also observed. Thus, this review describes potential mechanisms, which can lead to the development of such a state.

Endocrine Diseases and the Liver: An Update

The endocrine system is a complex interconnected system of organs that control corporeal processes and function. Primary endocrine organs are involved in hormonal production and secretion but rely on a bevy of signals from the hypothalamic-pituitary axis and secondary endocrine organs, such as the liver. In turn, proper hepatic function is maintained through hormonal signaling. Thus, the endocrine system and liver are codependent, and diseases affecting either organs can lead to alterations in function within their counterparts. This article explores the hepato-endocrine relationship, including the effects on endocrine diseases on the liver.

Effects of hormonal contraceptive phase and progestin generation on stress-induced cortisol and progesterone release

The stress response differs between women using hormonal contraception and naturally cycling women. Yet, despite ample evidence showing that the stress response differs across the menstrual cycle in naturally cycling women, limited work has investigated whether the stress response differs across the hormonal contraceptive cycle, during which synthetic hormones are taken most of the month but not all of it. To induce a stress response, women using hormonal contraception completed the cold pressor test during either the active phase, when hormones are present, or during the inactive phase, when hormones are not present. Saliva was collected and assayed for free cortisol and progesterone levels prior to stress onset, immediately after stress termination, and 15-min post stress onset. Free cortisol and progesterone increased to a similar degree across both hormonal contraceptive phases in response to the cold pressor test. Post-hoc investigation indicates that the progestin “generation” (classification of synthetic progestins based on the compounds they are derived from) can differentially affect the free steroid response to cold pressor test stress, with the largest effects observed in women using formulations containing second-generation progestins. These findings indicate that progestin generation, particularly second-generation progestins, may have a more impactful influence on the stress response than hormonal contraceptive cycle phase. Potential mechanisms driving this effect and need for additional research are discussed.

Relative adrenal insufficiency in cirrhotic patients with ascites (hepatoadrenal syndrome)

AIM

Relative adrenal insufficiency (RAI) has been reported in critically ill patients with cirrhosis. We evaluated the prevalence of RAI and its relationship to clinical course in non-septic cirrhosis patients with ascites.

METHODS

The study included 66 consecutive non-septic cirrhosis patients with ascites. RAI was defined by a delta cortisol lower than 9 μg/dL and/or a peak cortisol lower than 18 μg/dL.

RESULTS

Sixty-six patients with cirrhosis and ascites were studied. The mean Child-Turcotte-Pugh (CTP) and model for end stage liver disease (MELD) scores were 10.6 ± 1.9 and 21.5 ± 7.3, respectively. The prevalence of RAI in patients with cirrhosis and ascites was 47% (31/66). The prevalence of RAI in patients with and without spontaneous bacterial peritonitis, renal failure and type 1 hepatorenal syndrome (HRS) was comparable. Baseline hyponatremia was common in RAI (42% versus 17%, p = 0.026). There was a significant correlation of prevalence of RAI with prothrombin time, international normalized ratio, MELD scores and CTP class. During follow-up, there was no association between RAI and the risk to develop new infections, severe sepsis, type 1 HRS and death.

CONCLUSIONS

RAI is common in non-septic cirrhotic patients with ascites and its prevalence increases with severity of liver disease. However, it does not affect the short-term outcome in these patients.

Hypothalamus-Pituitary-Adrenal Dysfunction in Cholestatic Liver Disease

The Hypothalamic-Pituitary-Adrenal (HPA) axis has an important role in maintaining the physiological homeostasis in relation to external and internal stimuli. The HPA axis dysfunctions were extensively studied in neuroendocrine disorders such as depression and chronic fatigue syndrome but less so in hepatic cholestasis, cirrhosis or other liver diseases. The HPA axis controls many functions of the liver through neuroendocrine forward signaling pathways as well as negative feedback mechanisms, in health and disease. This review describes cell and molecular mechanisms of liver and HPA axis physiology and pathology. Evidence is presented from clinical and experimental model studies, demonstrating that dysfunctions of HPA axis are correlated with liver cholestatic disorders. The functional interactions of HPA axis with the liver and immune system in cases of bacterial and viral infections are also discussed. Proinflammatory cytokines stimulate glucocorticoid (GC) release by adrenals but they also inhibit bile acid (BA) efflux from liver. Chronic hepatic inflammation leads to cholestasis and impaired GC metabolism in the liver, so that HPA axis becomes depressed. Recently discovered interactions of GC with self-oscillating transcription factors that generate circadian rhythms of gene expression in brain and liver, in the context of GC replacement therapies, are also outlined.

The Evaluation of Adrenal Function in Two Cases of Hypocortisolism Accompanied by Liver Cirrhosis

Adrenal insufficiency may occur in patients with liver cirrhosis. The assessment of hypothalamus-pituitary-adrenal function is important in such patients, but there is no consensus as to how it should be performed. We herein report the results of our evaluation of the adrenal function in two patients with hypocortisolism accompanied by liver cirrhosis. The patients lacked the typical features of hypocortisolism. One was diagnosed with hypocortisolism accompanied by liver cirrhosis while the other had secondary adrenal insufficiency caused by a hypothalamic disorder. Hypocortisolism accompanied by liver cirrhosis should be evaluated by endocrine tests to determine its pathogenesis. A low-dose adrenocorticotropic hormone test may be appropriate for non-critically ill cirrhotic patients.

Adrenal insufficiency predicts early mortality in patients with cirrhosis

BACKGROUND

Adrenal insufficiency (AI), also known as hepato-adrenal syndrome, is a well-known entity in cirrhotic patients. However, factors associated with AI and its effect on survival are still not clear. We determined the prevalence of AI in patients with cirrhosis who had no hemodynamic instability or any acute deterioration, and studied its influence on short-term survival.

PATIENTS AND METHODS

In consecutive cirrhotic patients, presence of AI was determined either by total serum cortisol <18 µg/dl, 60 minutes after 250 µg synacthen injection, or when the delta-fraction (post-synacthen serum cortisol minus basal serum cortisol) was <9 µg/dl.

RESULTS

A total of 120 patients were included in the study (median age 50 years (range 27-73), males 87%). The median CTP and MELD scores were 10 (range 6-13) and 20 (range 6-40). The etiology of cirrhosis was alcohol (51%), cryptogenic (28%), viral (19%) and autoimmune (2%). Sixty-nine patients (58%) had AI and the remaining 51 (42%) had normal adrenal function. Serum bilirubin was significantly higher (p < 0.05) in the AI group, and total cholesterol, HDL, LDL and hemoglobin were significantly lower (p < 0.05) in the AI group. CTP score, MELD score, and basal cortisol levels were not different between those with and without AI (p = NS). By 120 days of follow-up, 41 patients had died. Thus, the 120-day survival was 66%, and this was higher in patients without AI than in patients with AI (78% vs 56%; p = 0.019). On multivariate analysis absence of AI, low WBC and low CTP score independently predicted 120-day survival.

CONCLUSIONS

AI is present in more than half of cirrhotic patients but does not parallel the severity scores of cirrhosis. Its presence predicts early mortality in these patients, and this prediction is independent of CTP or MELD scores.

Adrenocortical LDL receptor function negatively influences glucocorticoid output

Over 50% of the cholesterol needed by adrenocortical cells for the production of glucocorticoids is derived from lipoproteins. However, the overall contribution of the different lipoproteins and associated uptake pathways to steroidogenesis remains to be determined. Here we aimed to show the importance of LDL receptor (LDLR)-mediated cholesterol acquisition for adrenal steroidogenesis in vivo. Female total body LDLR knockout mice with a human-like lipoprotein profile were bilaterally adrenalectomized and subsequently provided with one adrenal either expressing or genetically lacking the LDLR under their renal capsule to solely modulate adrenocortical LDLR function. Plasma total cholesterol levels and basal plasma corticosterone levels were identical in the two types of adrenal transplanted mice. Strikingly, restoration of adrenal LDLR function significantly reduced the ACTH-mediated stimulation of adrenal steroidogenesis (P<0.001), with plasma corticosterone levels that were respectively 44-59% lower (P<0.01) as compared to adrenal LDLR negative controls. In addition, LDLR positive adrenal transplanted mice exhibited a significant decrease (-39%; P<0.001) in their plasma corticosterone level under fasting stress conditions. Biochemical analysis did not show changes in the expression of genes involved in cholesterol mobilization. However, LDLR expressing adrenal transplants displayed a marked 62% reduction (P<0.05) in the transcript level of the key steroidogenic enzyme HSD3B2. In conclusion, our studies in a mouse model with a human-like lipoprotein profile provide the first in vivo evidence for a novel inhibitory role of the LDLR in the control of adrenal glucocorticoid production.

Apolipoprotein AI and HDL are reduced in stable cirrhotic patients with adrenal insufficiency: a possible role in glucocorticoid deficiency

BACKGROUNDS AND AIMS

Adrenal insufficiency (AI) has been reported in patients with stable cirrhosis. A lack of substrates has been suggested as a possible contributing pathogenic mechanism leading to glucocorticoid deficiency in these subjects. To better explore this hypothesis, we studied lipoproteins in cirrhotics with and without AI.

METHODS

A total of 81 cirrhotic patients and 30 normal volunteers were enrolled. The severity of liver disease was graded by Child-Pugh score. Total cholesterol (TC), high-density lipoprotein (HDL), low-density lipoprotein (LDL), triglyceride (TG), and apolipoprotein AI (Apo-AI) levels were evaluated. HDL subfractions were measured by gradient gel electrophoresis. Adrenal function was assessed by the Low-Dose Short Synacthen Test.

RESULTS

Cirrhotic patients showed a significant reduction of TC, HDL, LDL, TG, and Apo-AI levels compared with controls. HDL3 was significantly lower, while HDL2 was higher, in cirrhotics compared with the controls. AI was observed in 26 patients. TC, TG, HDL, and Apo-AI were significantly reduced in cirrhotics with AI compared with those with normal adrenal function. HDL2 and HDL3 did not differ between these two groups. Delta cortisol was related to TC (r = 0.30, p < 0.01), TG (r = 0.22, p = 0.05), and Apo-AI (r = 0.37, p < 0.001). Multivariate analysis revealed that Apo-AI and HDL were independently associated with AI.

CONCLUSION

Our study shows that TC, TG, HDL, and Apo-AI are reduced in cirrhotics with AI. In particular, because both HDL and Apo-AI play a primary role in providing substrates for steroidogenesis to adrenal cells, this deficiency may contribute to the pathogenesis of AI in these patients.

Adrenal Function in females with low plasma HDL-C due to mutations in ABCA1 and LCAT

INTRODUCTION

Adrenal steroidogenesis is essential for human survival and depends on the availability of the precursor cholesterol. Male subjects with low plasma levels of high density lipoprotein (HDL) cholesterol are characterized by decreased adrenal function. Whether this is also the case in female subjects with low plasma HDL-C levels is unresolved to date.

FINDINGS

15 female ATP binding cassette transporter AI (ABCAI) and 14 female lecithin-cholesterol acyltransferase (LCAT) were included in the study. HDL-C levels were 38% and 41% lower in ABCA1 and LCAT mutation carriers compared to controls, respectively. Urinary steroid excretion of 17-ketogenic steroids or 17-hydroxy corticosteroids did not differ between 15 female ABCA1 mutation carriers (p = 0.27 vs 0.30 respectively) and 30 matched normolipidemic controls or between 14 female LCAT mutation carriers and 28 matched normolipidemic controls (p = 0.10 and 0.14, respectively). Cosyntropin testing in an unselected subgroup of 8 ABCA1 mutation carriers and 3 LCAT mutation carriers did not reveal differences between carriers and controls.

CONCLUSION

Adrenal function in females with molecularly defined low HDL-C levels is not different from controls. The discrepancy with the finding of impaired steroidogenesis in males with molecularly defined low HDL-C levels underscores the importance of gender specific analyses in cholesterol-related research.

Vascular aldosterone production at the pre-diabetic stage of young Otsuka Long-Evans Tokushima Fatty (OLETF) rats, compared with Long-Evans Tokushima Otsuka (LETO) rats

We examined the ability of aortic smooth muscle cells (AoSMC) prepared from spontaneously diabetic rats to produce aldosterone (Aldo) and the regulatory mechanism that controls their Aldo production. AoSMC of 6 week-old Long-Evans Tokushima Otsuka (LETO: the control group) and 6 week-old Otsuka Long-Evans Tokushima Fatty (OLETF: the type 2 diabetes group) rats were used in the present experiments. CYP11B2 (Aldo synthetase) mRNA expression was detected in both the LETO and OLETF AoSMC. Basal Aldo production was significantly greater (4-5 fold higher) in the OLETF AoSMC culture medium than in the LETO AoSMC culture medium. When AoSMC were co-incubated with high-density lipoproteins (HDL), supplying cholesterol as a substrate for steroidogenesis in rats, angiotensin II (AII) significantly increased greater Aldo production in the OLETF AoSMC than in the LETO AoSMC. The present data suggested that future onset of diabetic vascular dysfunction is partly caused by excess Aldo production by AoSMC in young OLETF rats. Concomitant stimulation by HDL and AII resulted in elevated Aldo production in the OLETF and the LETO AoSMC, and also demonstrated that AII-induced Aldo production is greatly enhanced by HDL in OLETF, rather than in LETO. In conclusion, our data clearly demonstrated that Aldo production in the OLETF AoSMC was significantly higher than in the LETO AoSMC, suggesting possible future onset of vascular dysfunction in diabetes, induced by local Aldo production in the AoSMC.

Assessment of adrenal function in liver diseases

BACKGROUND

In recent times, there are reports of adrenal dysfunction in whole spectrum of liver disease. Adrenal insufficiency (AI) has been shown to correlate with progression of liver disease. Hence this study was conducted to assess adrenal function in subjects with acute liver disease (ALD), chronic liver disease (CLD) and post liver transplantation (LT).

MATERIAL AND METHODS

This study included 25 healthy controls, 25 patients of ALD, 20 subjects of CLD with Child-Pugh stage A (CLD-1) and 30 with Child-Pugh stage B or C (CLD-2), and 10 subjects with LT. All subjects were assessed clinically, biochemically and for adrenal functions.

RESULTS

AI was present in 9 (34.6%) patients with ALD, 20 (40%) patients with CLD and 4 (40%) in subjects with LT. AI was more common in CLD-2 (18 patients - 60%) than CLD-1 (2 patients - 10%). All patients with chronic liver disease had significantly lower basal cortisol (8.8±4.8, P=0.01), stimulated cortisol (18.2±6.3, P <0.00001) and incremental cortisol (9.4±4.6, P <0.00001) as compared to controls. There was increase in percentage of subjects with adrenal dysfunction with progression of liver disease as assessed by Child-Pugh staging. AI was predicted by lower levels of serum protein, serum albumin, total cholesterol and HDL cholesterol and higher levels of serum bilirubin and INR. Adrenal functions showed recovery following liver transplantation.

CONCLUSIONS

AI forms important part of spectrum of acute and chronic liver disease. Deterioration of synthetic functions of liver disease predicts presence of AI, and these patients should be evaluated for adrenal dysfunction periodically.

High density lipoprotein as a source of cholesterol for adrenal steroidogenesis: a study in individuals with low plasma HDL-C

Few studies have addressed the delivery of lipoprotein-derived cholesterol to the adrenals for steroid production in humans. While there is evidence against a role for low-density lipoprotein (LDL), it is unresolved whether high density lipoprotein (HDL) contributes to adrenal steroidogenesis. To study this, steroid hormone profiles in urine were assessed in male subjects suffering from functional mutations in ATP binding cassette transporter A1 (ABCA1) (n = 24), lecithin:cholesterol acyltransferase (LCAT) (n = 40), as well as in 11 subjects with low HDL cholesterol (HDL-C) without ABCA1/LCAT mutations. HDL-C levels were 39% lower in the ABCA1, LCAT, and low HDL-C groups compared with controls (all P < 0.001). In all groups with low HDL-C levels, urinary excretion of 17-ketogenic steroids was reduced by 33%, 27%, and 32% compared with controls (all P < 0.04). In seven carriers of either type of mutation, adrenocorticotropic hormone (ACTH) stimulation did not reveal differences from normolipidemic controls. In conclusion, this study shows that basal but not stimulated corticosteroid metabolism is attenuated in subjects with low HDL-C, irrespective of its molecular origin. These findings lend support to a role for HDL as a cholesterol donor for basal adrenal steroidogenesis in humans.

Update on adrenal insufficiency in patients with liver cirrhosis

Liver cirrhosis is a major cause of mortality worldwide, often with severe sepsis as the terminal event. Over the last two decades, several studies have reported that in septic patients the adrenal glands respond inappropriately to stimulation, and that the treatment with corticosteroids decreases mortality in such patients. Both cirrhosis and septic shock share many hemodynamic abnormalities such as hyperdynamic circulatory failure, decreased peripheral vascular resistance, increased cardiac output, hypo-responsiveness to vasopressors, increased levels of proinflammatory cytokines [interleukine(IL)-1, IL-6, tumor necrosis factor-alpha] and it has, consequently, been reported that adrenal insufficiency (AI) is common in critically ill cirrhotic patients. AI may also be present in patients with stable cirrhosis without sepsis and in those undergoing liver transplantation. The term hepato-adrenal syndrome defines AI in patients with advanced liver disease with sepsis and/or other complications, and it suggests that it could be a feature of liver disease per se, with a different pathogenesis from that of septic shock. Relative AI is the term given to inadequate cortisol response to stress. More recently, another term is used, namely "critical illness related corticosteroid insufficiency" to define "an inadequate cellular corticosteroid activity for the severity of the patient's illness". The mechanisms of AI in liver cirrhosis are not completely understood, although decreased levels of high-density lipoprotein cholesterol and high levels of proinflammatory cytokines and circulatory endotoxin have been suggested. The prevalence of AI in cirrhotic patients varies widely according to the stage of the liver disease (compensated or decompensated, with or without sepsis), the diagnostic criteria defining AI and the methodology used. The effects of corticosteroid therapy on cirrhotic patients with septic shock and AI are controversial. This review aims to summarize the existing published information regarding AI in patients with liver cirrhosis.

Adrenocortical dysfunction in liver disease: a systematic review

In patients with cirrhosis, adrenal insufficiency (AI) is reported during sepsis and septic shock and is associated with increased mortality. Consequently, the term "hepato-adrenal syndrome" was proposed. Some studies have shown that AI is frequent in stable cirrhosis as well as in cirrhosis associated with decompensation other than sepsis, such as bleeding and ascites. Moreover, other studies showed a high prevalence in liver transplant recipients immediately after, or some time after, liver transplantation. The effect of corticosteroid therapy in critically ill patients with liver disease has been evaluated in some studies, but the results remain controversial. The 250-μg adreno-cortico-tropic-hormone stimulation test to diagnose AI in critically ill adult patients is recommended by an international task force. However, in liver disease, there is no consensus on the appropriate tests and normal values to assess adrenal function; thus, standardization of normal ranges and methodology is needed. Serum total cortisol assays overestimate AI in patients with cirrhosis, so that direct free cortisol measurement or its surrogates may be useful measurements to define AI, but further studies are needed to clarify this. In addition, the mechanisms by which liver disease leads to adrenal dysfunction are not sufficiently documented. This review evaluates published data regarding adrenal function in patients with liver disease, with a particular focus on the potential limitations of these studies as well as suggestions for future studies.

Assessment of adrenocortical reserve in stable patients with cirrhosis

BACKGROUND & AIMS

Adrenal insufficiency (AI) is reported in critically ill patients with cirrhosis and is associated with increased mortality. It is unclear if AI is an underlying condition or triggered by critical events (e.g. sepsis). We investigated AI in cirrhosis without infection or hemodynamic instability.

METHODS

A total of 101 consecutive patients with cirrhosis were studied. AI was defined by a total serum cortisol (TC) <18 μg/dl at 20 or 30 min after injection of 1 μg of tetracosactrin. Transcortin, calculated free cortisol (cFC), and free cortisol index (FCI) were assessed in a subgroup of 41 patients, with FCI>12 representing normal adrenal function.

RESULTS

AI was present in 38 patients (38%). Child score (median, 10 vs 7, p<0.0001), MELD score (median, 17 vs 12, p<0.0001), ascites (68% vs 37%, p<0.01), basal TC (median,7.6 vs 14.9 μg/dl, p<0.001), albumin (28 ± 0.8 vs 33 ± 0.7 g/L, p<0.0001), INR (median, 1.6 vs 1.2, p<0.0001), total bilirubin (median, 51 vs 31 μmol/L, p<0.05), total cholesterol (median, 120 vs 142, p<0.05), and LDL (median, 76 vs 81, p<0.05) were significantly different between those with and without AI. ROC curves showed a basal TC ≤ 12.8 μg/dl to be a cut-off value closely associated with AI. The cFC was significantly related to TC for baseline values (R=0.94, p<0.0001), peak values (R=0.90, p<0.0001), and delta values (R=0.95, p<0.0001), in patients with and without AI. However, no patient had a FCI<12.

CONCLUSIONS

AI defined by an abnormal response to 1 μg tetracosactrin is frequent in stable patients with cirrhosis, in the absence of infections or hemodynamic instability and is related to the severity of liver disease. However, evaluation of the true incidence of AI should comprise direct assays of free cortisol. Clinical consequences of AI need to be explored.

Digital fluorescence analysis of trafficking of single endosomes containing low-density lipoprotein in adrenocortical cells: facilitation of centripetal motion by adrenocorticotropic hormone

Imaging of trafficking of endosomes containing low-density lipoprotein (LDL) is useful to analyze cholesterol transport in adrenocortical cells. At 60 min after the application of fluorescently labeled LDL to adrenocortical cells, individual endosomes containing LDL were demonstrated to undergo frequent switching between forward and reverse movement and immobility. The population of moving endosomes (>or=0.065 microm/s) was approximately 75% in control cells. The remaining endosomes were either slowly moving or temporarily immobile. At 3h after the LDL addition, endosomes were concentrated around the circumference of the cell nuclei. The endosome movement was inhibited by nocodazole, implying that endosomes undergo movement along microtubule networks. Anti-dynein antibodies inhibited the motion of endosomes towards the nucleus, and anti-kinesin antibodies inhibited peripherally directed motion. These results imply that both dynein-like and kinesin-like motor proteins bind to the same endosome, resulting in saltatory movements with centripetal or peripherally directed direction, depending on which motor binds to microtubules. Though the dynein and kinesin motors drive the endosomes very rapidly (microm/s), frequent saltatory motions of single endosomes may induce the very slow net centripetal motion (microm/h).The application of adrenocorticotropic hormone (ACTH) resulted in a facilitation of the centripetal motion of endosomes, resulting in the establishment of the concentration of endosomes around cell nuclei within 1 h.

Endocrine and liver interaction: the role of endocrine pathways in NASH

This article reviews evidence that causally links hormonal disorders with hepatobiliary disease, and gives particular focus to nonalcoholic steatohepatitis (NASH). The downstream mechanisms by which endocrine disturbances cause liver disease might be similar to those involved in the development of primary liver disease. Hypothyroidism, for example, might lead to NASH, cirrhosis and potentially liver cancer via the development of hyperlipidemia and obesity. Patients with growth hormone deficiency have a metabolic-syndrome-like phenotype that is also associated with the development of NASH. Polycystic ovary syndrome is a common endocrine disorder that is often associated with insulin resistance, the metabolic syndrome, altered levels of liver enzymes and the development of NASH. Recent findings support a role of dehydroepiandrosterone sulfate deficiency in the development of advanced NASH. In addition, adrenal failure is increasingly reported in patients with end stage liver disease and in patients who have received a liver transplant, which suggests a bidirectional relationship between liver and endocrine functions. Clinicians should, therefore, be aware of the potential role of endocrine disorders in patients with cryptogenic liver disease and of the effects of liver function on the endocrine system.

Critical illness-related corticosteroid insufficiency

The diagnosis of adrenal failure and the indications for corticosteroid therapy in critically ill patients are controversial. This controversy is fueled by the complexity of the issues and the paucity of data from high quality clinical trials. Nevertheless, while the use of high-dose corticosteroids in patients with severe sepsis and ARDS failed to improve outcome and was associated with increased complications, an extended course of stress-dose corticosteroids has been reported to increase the occurrence of ventilator-free days and survival in select groups of ICU patients. These patients typically have an exaggerated proinflammatory response. Until recently the exaggerated proinflammatory response that characterizes critically ill patients with systemic inflammation has focused on suppression of the hypothalamic-pituitary-adrenal axis and adrenal failure. However, experimental and clinical data suggest that glucocorticoid tissue resistance may also play an important role. This complex syndrome is referred to as critical illness-related corticosteroid insufficiency (CIRCI) and is defined as inadequate corticosteroid activity for the severity of the illness of a patient. The paper reviews cortisol physiology, CIRCI, and the role of corticosteroid therapy in critically ill patients.

Effect of very low LDL-cholesterol on cortisol synthesis

BACKGROUND

Cardiovascular disease is the most common cause of mortality around the world. The relationship between coronary artery disease and serum LDL-cholesterol levels has become obvious in recent years and statin treatment has been used more commonly. However, influence of intensive statin treatment on steroidal hormonal functions has remained unclear. In this paper, we evaluated the effect of very low LDL levels (<70 mg/dl) on serum cortisol concentrations, which is mainly synthesized from cholesterol.

SUBJECTS AND METHODS

Forty-one patients with serum LDL-cholesterol levels below 70 mg/dl were included in the study. The control group consisted of 38 healthy people. Adrenal axis was evaluated by means of cortisol response to 1 microg ACTH test.

RESULTS

The mean age of patients was 52.45+/-10.74 yr. Of 41 patients, 19 (46.9%) were female. There were statistically significant differences between the study and control group according to their serum cholesterol and LDL levels. Main serum LDL levels were 58+/-11.4 mg/dl and 131+/-25.8 mg/dl in the study and control group, respectively. There were no statistically significant differences in response to 1 microg ACTH stimulation test at basal, 30 min and 60 min among both study and control group. Atorvastatin treatment was generally well tolerated.

CONCLUSIONS

Our data reflect that having serum LDL-cholesterol levels below 70 mg/dl did not affect the adrenal axis function in terms of cortisol.

Recommendations for the diagnosis and management of corticosteroid insufficiency in critically ill adult patients: consensus statements from an international task force by the American College of Critical Care Medicine

OBJECTIVE

To develop consensus statements for the diagnosis and management of corticosteroid insufficiency in critically ill adult patients.

PARTICIPANTS

A multidisciplinary, multispecialty task force of experts in critical care medicine was convened from the membership of the Society of Critical Care Medicine and the European Society of Intensive Care Medicine. In addition, international experts in endocrinology were invited to participate.

DESIGN/METHODS

The task force members reviewed published literature and provided expert opinion from which the consensus was derived. The consensus statements were developed using a modified Delphi methodology. The strength of each recommendation was quantified using the Modified GRADE system, which classifies recommendations as strong (grade 1) or weak (grade 2) and the quality of evidence as high (grade A), moderate (grade B), or low (grade C) based on factors that include the study design, the consistency of the results, and the directness of the evidence.

RESULTS

The task force coined the term critical illness-related corticosteroid insufficiency to describe the dysfunction of the hypothalamic-pituitary-adrenal axis that occurs during critical illness. Critical illness-related corticosteroid insufficiency is caused by adrenal insufficiency together with tissue corticosteroid resistance and is characterized by an exaggerated and protracted proinflammatory response. Critical illness-related corticosteroid insufficiency should be suspected in hypotensive patients who have responded poorly to fluids and vasopressor agents, particularly in the setting of sepsis. At this time, the diagnosis of tissue corticosteroid resistance remains problematic. Adrenal insufficiency in critically ill patients is best made by a delta total serum cortisol of < 9 microg/dL after adrenocorticotrophic hormone (250 microg) administration or a random total cortisol of < 10 microg/dL. The benefit of treatment with glucocorticoids at this time seems to be limited to patients with vasopressor-dependent septic shock and patients with early severe acute respiratory distress syndrome (PaO2/FiO2 of < 200 and within 14 days of onset). The adrenocorticotrophic hormone stimulation test should not be used to identify those patients with septic shock or acute respiratory distress syndrome who should receive glucocorticoids. Hydrocortisone in a dose of 200 mg/day in four divided doses or as a continuous infusion in a dose of 240 mg/day (10 mg/hr) for > or = 7 days is recommended for septic shock. Methylprednisolone in a dose of 1 mg x kg(-1) x day(-1) for > or = 14 days is recommended in patients with severe early acute respiratory distress syndrome. Glucocorticoids should be weaned and not stopped abruptly. Reinstitution of treatment should be considered with recurrence of signs of sepsis, hypotension, or worsening oxygenation. Dexamethasone is not recommended to treat critical illness-related corticosteroid insufficiency. The role of glucocorticoids in the management of patients with community-acquired pneumonia, liver failure, pancreatitis, those undergoing cardiac surgery, and other groups of critically ill patients requires further investigation.

CONCLUSION

Evidence-linked consensus statements with regard to the diagnosis and management of corticosteroid deficiency in critically ill patients have been developed by a multidisciplinary, multispecialty task force.

Mechanisms and clinical consequences of critical illness associated adrenal insufficiency

PURPOSE OF REVIEW

Adrenal insufficiency is being diagnosed with increasing frequency in critically ill patients. There exists, however, much controversy in the literature as to the nature of this entity, including its pathophysiology, epidemiology, diagnosis and treatment. The review summarizes our current understanding of the causes and consequences of adrenal insufficiency in critically ill patients.

RELEVANT FINDINGS

Activation of the hypothalamic-pituitary-adrenal axis with the production of cortisol is a fundamental component of the stress response and is essential for survival of the host. Dysfunction of the hypothalamic-pituitary-adrenal axis with decreased glucocorticoid activity is being increasingly recognized in critically ill patients, particularly those with sepsis. This condition is best referred to as 'critical illness-related corticosteroid insufficiency'. Critical illness-related corticosteroid insufficiency may occur due to dysfunction at any point in the hypothalamic-pituitary-adrenal axis including tissue glucocorticoid resistance. Critical illness-related corticosteroid insufficiency leads to an exaggerated proinflammatory response with increased tissue injury and organ dysfunction.

SUMMARY

Critical illness-related corticosteroid insufficiency is common in critically ill patients, particularly those with sepsis. Supplemental corticosteroids may restore the balance between the pro-and anti-inflammatory mediators in patients with severe sepsis, septic shock and acute respiratory distress syndrome, and thereby improve the outcome of patients with these conditions.

Adrenal-exhaustion syndrome in patients with liver disease

OBJECTIVE

Adrenal failure is emerging as an important cause of excess morbidity and mortality in critically ill patients. We have recently reported the high incidence of adrenal failure in patients with liver disease, the so called "hepato-adrenal syndrome." It has been noted that patients who on initial testing may have "normal" adrenal function subsequently progress to overt adrenal failure, the adrenal-exhaustion syndrome. The goal of this study was to further characterize this syndrome.

DESIGN

Retrospective review of the "Hepatic Cortisol Research and Adrenal Pathophysiology Study" database.

SETTING

Liver transplant ICU of a tertiary care university hospital.

PATIENTS AND METHODS

Patients who on initial testing had "normal" adrenal function were followed, and adrenal function testing was repeated in those who failed to improve. The patients were grouped as follows: (1) patients who developed adrenal failure on follow-up testing; and (2) patients who had normal adrenal function during their ICU stay. The incidence and risk factors for the development of adrenal-exhaustion syndrome were determined.

MEASUREMENTS AND RESULTS

The study cohort consisted of 221 patients, of whom 120 (54%) were diagnosed with adrenal insufficiency on initial diagnostic testing and were excluded from further analysis. The remaining 101 patients comprised those who made up the group of interest. On follow-up, 16 (16%) of these developed adrenal failure a mean of 3 days after initial testing. The only factor that predicted the development of adrenal-exhaustion syndrome was a low HDL level (p<0.001).

CONCLUSION

This study demonstrates that adrenal failure is a dynamic process and that repeat adrenal function testing is indicated in patients who remain hemodynamically unstable or fail to improve with aggressive supportive treatment. Low HDL levels may be pathogenetically linked to the development of adrenal failure.

Dyslipidemia in the Critically Ill

Total and HDL cholesterol levels fall at the onset of acute illness and the cholesterol levels normalize as the patient recovers. Hypocholesterolemia may predispose the critically ill patient to sepsis and adrenal failure. Early enteral nutrition and tight glycemic control accelerate the recovery of the cholesterol levels.

The hepatoadrenal syndrome: a common yet unrecognized clinical condition

OBJECTIVE

Adrenal failure is common in critically ill patients, particularly those with sepsis. As liver failure and sepsis are both associated with increased circulating levels of endotoxin and proinflammatory mediators and reduced levels of apoprotein-1/high-density lipoprotein, we postulated that adrenal failure may be common in patients with liver disease.

DESIGN

Clinical study.

SETTING

Liver transplant intensive care unit.

PATIENTS

The study cohort included 340 patients with liver disease.

INTERVENTIONS

Based on preliminary observational data, all patients admitted to our 28-bed liver transplant intensive care unit (LTICU) undergo adrenal function testing. An honest broker system was used to extract clinical, hemodynamic, medication, and laboratory data on patients admitted to the LTICU from March 2002 to March 2004. A random (stress) cortisol level <20 microg/dL in a highly stressed patient (respiratory failure, hypotension) was used to diagnose adrenal insufficiency. In all other patients, a random cortisol level <15 microg/dL or a 30-min level <20 microg/dL post-low-dose (1 microg) cosyntropin was considered diagnostic of adrenal insufficiency. Patients were grouped as follows: a) chronic liver failure; b) fulminant hepatic failure; c) patients immediately status post-orthotopic liver transplantation receiving a steroid-free protocol of immunosuppression; and d) patients status post-remote liver transplant (>/=6 months). The decision to treat patients with stress doses of hydrocortisone was at the discretion of the treating intensivist and transplant surgeon.

MEASUREMENTS AND MAIN RESULTS

Two-hundred and forty-five (72%) patients met our criteria for adrenal insufficiency (the hepatoadrenal syndrome). Eight (33%) patients with fulminant hepatic failure, 97 (66%) patients with chronic liver disease, 31(61%) patients with a remote history of liver transplantation, and 109 (92%) patients who had undergone liver transplantation under steroid-free immunosuppression were diagnosed with adrenal insufficiency. The high-density lipoprotein level at the time of adrenal testing was the only variable predictive of adrenal insufficiency (p < .0001). In vasopressor-dependent patients with adrenal insufficiency, treatment with hydrocortisone was associated with a significant reduction (p = .02) in the dose of norepinephrine at 24 hrs, whereas the dose of norepinephrine was significantly higher (p = .04) in those patients with adrenal failure not treated with hydrocortisone. In vasopressor-dependent patients without adrenal insufficiency, treatment with hydrocortisone did not affect vasopressor dose at 24 hrs. One hundred and forty-one patients (26.4%) died during their hospitalization. The baseline serum cortisol was 18.8 +/- 16.2 microg/dL in the nonsurvivors compared with 13.0 +/- 11.8 microg/dL in the survivors (p < .001). Of those patients with adrenal failure who were treated with glucocorticoids, the mortality rate was 26% compared with 46% (p = .002) in those who were not treated. In those patients receiving vasopressor agents at the time of adrenal testing, the baseline cortisol was 10.0 +/- 4.8 microg/dL in those with adrenal insufficiency compared with 35.6 +/- 21.2 microg/dL in those with normal adrenal function. Vasopressor-dependent patients who did not have adrenal failure had a mortality rate of 75%.

CONCLUSIONS

Patients with liver failure and patients post-liver transplantation have an exceedingly high incidence of adrenal failure, which may be pathophysiologically related to low levels of high-density lipoprotein. Treatment of patients with adrenal failure may improve outcome. High baseline serum cortisol levels may be a maker of disease severity and portend a poor prognosis.

Acute inflammation increases selective uptake of HDL cholesteryl esters into adrenals of mice overexpressing human sPLA2

The acute-phase protein secretory phospholipase A2 (sPLA2) influences the metabolism of high-density lipoproteins (HDL). The adrenals are known to utilize HDL cholesterol as a source of sterols. The aim of the present study was to test the hypothesis that sPLA2 enhances the selective uptake of HDL into the adrenals in response to acute inflammation as a possible physiological role for the sPLA2-HDL interaction. Human sPLA2-transgenic mice, in which sPLA2 expression is upregulated by inflammatory stimuli, were used. Ten hours after induction of the acute-phase response (APR) by injection of bacterial lipopolysaccharide (LPS), plasma levels of HDL cholesterol decreased significantly in sPLA2-transgenic mice (-18%, P < 0.05) but remained unchanged in wild-type mice. The fractional catabolic rates of both 125I-labeled tyraminecellobiose (TC)-HDL and [3H]cholesteryl ether increased significantly in the sPLA2-transgenic mice after induction of the APR (0.18 +/- 0.01 vs. 0.21 +/- 0.01 pool/h, P < 0.05, and 0.31 +/- 0.02 vs. 0.42 +/- 0.05 pool/h, P < 0.05, respectively) but remained unchanged in the wild-type mice (0.10 +/- 0.01 vs. 0.22 +/- 0.02 pool/h, respectively). After induction of the APR, in both groups HDL holoparticle uptake by the liver was increased (P < 0.001). sPLA2-transgenic mice had 2.4-fold higher selective uptake into the adrenals after induction of the APR than wild-type mice (156 +/- 6 vs. 65 +/- 5%/ micro g tissue protein, P < 0.001). In summary, upregulation of sPLA2 expression during the APR specifically increases the selective uptake of HDL cholesteryl ester into the adrenals. These data suggest a novel metabolic role for sPLA2: modification of HDL during the APR to promote increased adrenal uptake of HDL cholesteryl ester to serve as source for steroid hormone synthesis.

Scavenger receptor class BI and selective cholesteryl ester uptake: partners in the regulation of steroidogenesis

The steroidogenic tissues have a special requirement for cholesterol, which is used as a substrate for steroid hormone biosynthesis. In many species this cholesterol is obtained from plasma lipoproteins by a unique pathway in which circulating lipoproteins bind to the surface of the steroidogenic cells and contribute their cholesteryl esters to the cells by a 'selective' process in which the whole lipoprotein particle does not enter the cell. This review describes the lipoprotein selective cholesteryl ester uptake process and its specific partnership with the HDL receptor, scavenger receptor class BI (SR-BI). It describes the characteristics of the selective pathway, and the molecular properties, localization, regulation, anchoring sites and potential mechanisms of action of SR-BI in facilitating cholesteryl ester uptake by steroidogenic cells.

Physical activity may modulate effects of ApoE genotype on lipid profile

Increased levels of physical activity may improve the lipid profile, but is this effect identical across apolipoprotein E (apoE) genotypes? A population-based cross-sectional survey conducted from 1999 to 2000 included 1708 randomly selected men and women aged 35 to 74 years. A validated physical activity questionnaire measured, for each participant, the total energy expenditure and its percentage used in high-intensity activities (%high-intensity activity), eg, brisk walking and sports. The effects of the apoEx%high-intensity activity interaction on the lipid profile were investigated by using multiple linear regression models. Among men, increased %high-intensity activity had greater protective effects in the apoE4 group regarding (1) high density lipoprotein (HDL) cholesterol (P<0.001), compared with either the apoE2 (interaction P=0.05) or apoE3 (interaction P<0.03) groups, and (2) triglycerides (P<0.03), compared with the apoE3 group (interaction P=0.07). A 10% increase of %high-intensity activity by an apoE4 man would correspond with a 0.07-mmol/L increase in HDL cholesterol and a -0.15-mmol/L decrease in triglycerides. Among women, only the protective effects of physical activity on HDL cholesterol in the apoE4 group versus the apoE2 group was statistically significant. Spending a larger fraction of the total energy expenditure in high-intensity activities may counteract the atherogenic effects of the epsilon4 allele on the lipid profile.

Angiotensin II promotes selective uptake of high density lipoprotein cholesterol esters in bovine adrenal glomerulosa and human adrenocortical carcinoma cells through induction of scavenger receptor class B type I

Angiotensin II is one of the main physiological regulators of aldosterone biosynthesis in the zona glomerulosa of the adrenal cortex. The hormone stimulates intracellular cholesterol mobilization to the mitochondrion for steroid biosynthesis. Here we have examined whether angiotensin II also modulates exogenous lipoprotein cholesterol ester supply to the steroidogenic machinery and whether this control is exerted on the selective transport of high density lipoprotein-derived cholesterol ester to intracellular lipid droplets through the scavenger receptor class B type I. In bovine adrenal glomerulosa and human NCI H295R adrenocortical carcinoma cells, high density lipoprotein stimulated steroid production. Angiotensin II pretreatment for 24 h potentiated this response. Fluorescence microscopy of cellular uptake of reconstituted high density lipoprotein containing a fluorescent cholesterol ester revealed an initial, time-dependent narrow labeling of the cell membrane followed by an intense accumulation of the fluorescent cholesterol ester within lipid droplets. At all time points, labeling was more pronounced in cells that had been treated for 24 h with angiotensin II. Fluorescence incorporation into cells was prevented by a monoclonal antibody directed against apolipoprotein A-I. Upon quantitative fluorometric determination, cholesterol ester uptake in angiotensin II-treated bovine cells was increased to 175 +/- 15% of controls after 2 h and to 260 +/- 10% after 4 h of exposure to fluorescent high density lipoprotein. The amount of scavenger receptor class B type I protein detected in cells treated with angiotensin II for 24 h reached 203 +/- 12% of that measured in control cells (n = 3, P < 0.01). In contrast, low density lipoprotein receptors were only minimally affected by angiotensin II treatment. This increase in scavenger receptor class B type I protein was associated with a 3-fold induction of scavenger receptor class B type I mRNA, which could be prevented by actinomycin D but not by cycloheximide. Similar results were obtained in the human adenocarcinoma cell line H295R. These observations show that angiotensin II regulates the scavenger receptor class B type I-mediated selective transport of lipoprotein cholesterol ester across the cell membrane as a major source of precursor for mineralocorticoid biosynthesis in both human and bovine adrenal cells.