Relation between cortisol and metabolic dysfunction-associated steatotic liver disease: A dog chasing its tail

Abstract

Patients with hypercortisolism and metabolic dysfunction-associated steatotic liver disease (MASLD) share several common comorbidities. Notably, individuals with Cushing’s syndrome appear to have a higher prevalence of MASLD, suggesting a potential pathogenic role of cortisol in the development of this liver condition. The liver is a key target of cortisol action, and it promotes both gluconeogenesis and lipogenesis. Simultaneously, the liver is a major site for cortisol metabolism and clearance. This dual role supports the notion that the liver should be considered an integral component of the hypothalamic-pituitary-adrenal axis. In this minireview, we examine current evidence linking MASLD with hypercortisolism, discuss the principal molecular and metabolic pathways through which cortisol affects liver function, and explore the potential of using cortisol metabolites as novel biomarkers of liver status in this context.

Key Words: Metabolic dysfunction-associated steatotic liver disease; Cushing syndrome; Liver; Hypercortisolism; Hepatic steatosis; Metabolic syndrome; Nonalcoholic fatty liver disease

Core Tip: Hypercortisolism and metabolic dysfunction-associated steatotic liver disease share multiple comorbidities, with a higher prevalence in Cushing’s syndrome, indicating that cortisol contributes to liver pathogenesis. As a key target and major metabolic site of cortisol, the liver is integral to the hypothalamic-pituitary-adrenal axis. This minireview summarizes their association, underlying molecular pathways, and cortisol metabolites as potential liver biomarkers.

INTRODUCTION

The rising prevalence of obesity and type 2 diabetes mellitus has led to an increase in diagnosis of metabolic dysfunction-associated steatotic liver disease (MASLD)[1]. MASLD is currently the most common chronic liver condition worldwide, affecting an estimated 25%-30% of the global population[1,2]. It is characterized by the accumulation of lipids in the liver in individuals with at least one component of metabolic syndrome (overweight or obesity, dysglycaemia or type 2 diabetes, hypertriglyceridemia, hypercholesterolemia, or hypertension)[3,4]. Increased lipid deposition can determine increased reactive oxygen species production and hepatic inflammation[5]. MASLD encompasses a broad spectrum of liver conditions, ranging from simple hepatic steatosis to metabolic dysfunction-associated steatohepatitis (MASH) and varying degrees of fibrosis (F0 to F4)[3,6]. It is considered a leading cause of liver cirrhosis and hepatocellular carcinoma, as well as of extrahepatic complications, mostly cardiovascular events and extrahepatic cancers, with metabolic risk factors serving as the primary drivers of disease progression. The role of glucocorticoids in the pathogenesis of nonalcoholic fatty liver disease (NAFLD) has been explored[7,8]. Patients with endogenous Cushing’s syndrome (CS) and those exposed to glucocorticoid exhibit MASLD[9,10]. Excess cortisol is linked to increased hunger, visceral obesity, insulin resistance, and dyslipidemia; all of which are recognized risk factors for MASLD[11]. Cortisol appears to have a direct effect on hepatic fat accumulation, beyond its role in promoting obesity and visceral adiposity[11].

In this minireview, we move beyond a classical and previously explored unidirectional view of cortisol excess as a mere driver of metabolic dysfunction and propose a novel, bidirectional framework linking cortisol and liver disease. We first describe the distinctive features of MASLD in patients with CS, then dissect the cortisol-mediated molecular and metabolic pathways that promote hepatic steatosis and progression of liver injury. Importantly, we highlight emerging evidence that the liver is not only a target of cortisol excess but also an active regulator of systemic and local glucocorticoid metabolism, thereby perpetuating cortisol dysregulation in a self-reinforcing, “dog-chasing-its-tail” loop. Finally, we discuss how alterations in circulating and urinary steroid profiles, including the urinary steroid metabolome, may serve as innovative prognostic tools to stage disease severity and refine risk stratification in patients with MASLD.

REVIEW METHODOLOGY

Although this is a narrative minireview, it is based on an in-depth and systematic exploration of the available literature. We carefully selected articles that were most relevant to the topic, with an emphasis on high-quality and up-to-date studies. Literature searches were conducted using PubMed, Scopus, and Web of Science, and the reference lists of selected articles were manually reviewed to identify additional relevant publications.

CORTISOL PHYSIOLOGY

Glucocorticoids are steroid hormones secreted by the adrenal cortex under the control of the hypothalamic-pituitary-adrenal axis[12,13]. They play a crucial role in the response to stress and are involved in various physiological processes, including inflammation and metabolism[14-16]. Cortisol secretion is under the hypothalamic-pituitary control (Figure 1A)[17]. Corticotropin-releasing hormone is secreted by the paraventricular nucleus of the hypothalamus. It then acts on the corticotropic cells located in the anterior pituitary to promote adrenocorticotropin secretion, which in turn, binds to melanocortin 2 receptor on the adrenal cortex to stimulate cortisol synthesis[17]. A review of all the pathways involved in steroidogenesis is beyond the scope of this paper and can be found in a recent publication by Kater et al[18]. Therefore, we only focus on those aspects relevant to understanding the complex liver/cortisol relation. Once secreted in the circulation, normally, only 5%-10% of cortisol circulates freely, while the majority is bound to cortisol-binding globulin (90%-95%) and albumin (5%-10%)[19]. Beyond the adrenal glands, peripheral metabolism is fundamental in regulating cortisol availability and activity at target tissues. In this context, the liver emerges as a key modulator of cortisol levels and function. 11β-Hydroxysteroid dehydrogenases (HSD) and ketoreductase are highly expressed in the liver[20,21]. Cortisol is a liposoluble molecule that freely diffuses across the cell membrane[17,22], but importantly, only the free form is able to do so. Once in the cytoplasm, cortisol binds to glucocorticoid receptor, determining a change in structure and the recruitment of co-regulatory protein that mediate transcriptional control[22,23]. Glucocorticoid receptor belongs to the nuclear receptor family, and upon binding, it translocases to the nucleus, where it regulates gene expression after binding glucocorticoid response elements[24].

Figure 1 Role of cortisol in liver metabolism and its metabolic pathways. A: Cortisol is produced upon stimulation by adrenocorticotropic hormone. In the liver, it enhances gluconeogenesis, fatty acid absorption, and lipogenesis, thereby increasing the risk of liver steatosis; B: Cortisone is metabolized by 11β-hydroxysteroid dehydrogenase type 1 into cortisol, and by 5α-reductase and 5β-reductase into inactive metabolites. ACTH: Adrenocorticotropic hormone; FA: Fatty acid; 11β-HSD1: 11β-hydroxysteroid dehydrogenase type 1; 5α-R: 5α-reductase; 5β-R: 5β-reductase.

ENDOGENOUS HYPERCORTISOLISM AND MASLD

In this section, endogenous hypercortisolism is utilized as a model to examine the impact of cortisol on liver pathology. This condition provides a unique framework for investigation, as affected individuals typically lack confounding factors that might otherwise influence hepatic alterations. Metabolic complications are common in patients with CS[25]. Most studies have focused on diabetes, dyslipidemia, and obesity. Impairments in glucose metabolism affect nearly 70% of individuals with CS, with 20%-45% diagnosed with diabetes and the remainder exhibiting impaired glucose tolerance[26]. Dyslipidemia is also a frequent finding in this population[27]. In our previous study, in 48 patients with CS, we found a prevalence of ~40% of dyslipidemia according to 1999 World Health Organization/International Society of Hypertension guidelines. A retrospective study by Dhingra et al[28] reported an alteration of lipid metabolism in 65% of 68 patients of South Asian Indian origin; a population in which dyslipidemia is more frequent than in other ethnic groups. Notably, only glycemia correlated with cortisol values, while no significant correlation was found regarding dyslipidemia[29]. Around 40% of patients with CS suffer from obesity[29]. In particular, CS is associated with visceral obesity, which is linked to adverse metabolic effects[30]. Around 60% of liver fat derives from nonesterified fatty acids stored in the visceral adipose tissue[31]. CS patients therefore exhibit multiple metabolic risk factors for MASLD[8]. However, fewer, mainly retrospective studies, have examined the prevalence of MASLD in patients with CS compared to other comorbidities (Table 1). Using ICD10 codes, a Chinese retrospective study found that 27.4% of CS patients also had MASLD[10]. Being a retrospective study based on ICD10 codes the risk of missing patients due to lack of registration of the code or poor screening is high. Another group from the UK reported a 20% prevalence of hepatic steatosis in patients with CS, using a liver-to-spleen computed tomography attenuation ratio of < 1 as the diagnostic criterion[32]. Similarly, a recent study by Marengo et al[33] reported a MASLD prevalence of 26.5% among individuals with CS. Steatosis was determined by ultrasound or computed tomography, enforcing the same criteria as in the previous study. Hepatic steatosis appears to be more common in patients with CS, adrenal adenoma, and adrenal hyperplasia compared to those with adrenocortical carcinoma or ectopic CS[33], suggesting that length of exposure could have a more important effect compared to cortisol values. The authors explored the use of fibrosis 4, enhanced liver investigation scoring tool, and NAFLD fibrosis score to evaluate whether patients with hepatic steatosis had fibrosis. Out of 13 patients with hepatic steatosis, only two had an increased risk of advanced fibrosis (on using the enhanced liver investigation scoring tool and one using the NAFLD fibrosis score)[33]. However, it is important to note that these observations are based on studies involving a small number of patients and the number of patients with follow-up was too small to understand the history of MASLD in CS[33]. Liver attenuation and the liver-to-spleen ratio correlated with total abdominal fat area, visceral fat area, percentage of visceral fat, and visceral-to-subcutaneous fat ratio[32]. A recent study reported a significantly higher prevalence of liver steatosis, with rates reaching 66% in patients with CS and similarly elevated levels in those with mild autonomous cortisol secretion[34]. To confirm the importance of long-term exposure to high cortisol levels, there is the increased prevalence of hepatic steatosis even in patients with mild autonomous cortisol secretion[34,35]. Patients with adrenal incidentaloma with mild autonomous cortisol secretion present with higher frequency of fatty liver compared to patients with nonfunctioning adenomas but lower than patients with CS[34]. In contrast, it is worth mentioning that even MASLD can alter metabolism of cortisol, for example a cross-sectional study investigated 24 h urinary free cortisol (UFC) and post-Nugent test levels of cortisol in 50 patients with biopsy-proven MASLD and 40 controls. Patients with MASLD had higher levels of UFC and reduced suppression after Nugent compared to controls[36]. Moreover, higher UFC and reduced post-Nugent suppression was seen in patient with biopsy proven MASH compared to patients with biopsy proven steatosis[36].

Table 1 Studies reporting prevalence of metabolic dysfunction-associated steatotic liver disease in patients with endogenous hypercortisolism.

Ref.	Number of patients	Patients	MASLD criteria for diagnosis	Results	Additional findings and comments
Marengo et al[33]	49	27 CS; 10 adrenal adenoma; 6 adrenal hyperplasia; 1 ACC; 5 ectopic ACTH	Reported on ultrasound. TC (liver/spleen attenuation ratio)	26% of liver steatosis	MASLD appears to be more frequent in adrenal adenomas. Data on follow up are limited from the small number of patients
Rockall et al[32]	50	50 CS	Liver/spleen attenuation ratio	20% of liver steatosis	The author showed a correlation between hepatic steatosis and abdominal fat area and visceral fat area
Zhou et al[10]	1652	905 CD; 16 ACC; 30 primary pigmented nodular adrenocortical disease; 346 adrenal adenomas; 102 bilateral macronodular adrenal hyperplasia; 98 ectopic; 20 unknown	ICD10 codes	24.5% liver steatosis	The study is retrospective and based on ICD10 codes and therefore there is high risk of bias
Candemir et al[35]	40	40 metabolically healthy MACS	Liver/spleen attenuation ratio	25%	The authors found that DEX1 response is a predictor of MASLD
Yu et al[34]	159	100 MACS; 59 CS	Liver/spleen attenuation ratio	57% in MACS; 66% CS	TyG-index, and HOMA-IR are critical markers in the development of nonalcoholic fatty liver disease in patients with excess cortisol

MASLD: Metabolic dysfunction-associated steatotic liver disease; CS: Cushing’s syndrome; ACC: Adrenocortical cancer; ACTH: Adrenocorticotropic hormone; CD: Cushing’s disease; MACS: Mild autonomous cortisol secretion; TC: Total cholesterol; DEX 1: 1 milligram dexhametasone suppression test; TyG: Triglyceride glucose; HOMA-IR: Homeostasis model assessment of insulin resistance.

ROLE OF 11-HSD1

The liver is a key target of cortisol action and metabolism. The effect of cortisol is not only dependent on its circulating levels but also on its concentrations at target tissues, which are primarily regulated at the pre-receptor level by 11β-HSD1, 11β-HSD2, and 5α-reductases. 11β-HSD1 converts inactive cortisone to active cortisol within cells and is critical in mediating cortisol-induced lipogenesis in the liver. Overexpression of 11β-HSD1 in the adipose tissue in mice, Zucker fat rats, and obese adults is linked to visceral adipose tissue deposition[37-39]. Evidence from animal studies supports a causative role of 11β-HSD1 in metabolic dysregulation. Recombinant 11β-HSD1 knockout mice are protected from stress or obesity-induced hyperglycemia[40], while inhibition of 11β-HSD1 in rodent models mitigated liver steatosis and reduced activation of hepatic stellate cells acting on the β-catenin Smad2/3 pathway[41-43]. Transfection of Hep1-6 hepatocytes with 11β-HSD1 resulted in significant fat accumulation compared to controls[44]. In humans, hepatic expression of 11β-HSD1 correlates positively with visceral and subcutaneous adipose tissue, glucose and alanine aminotransferase[37]. Genetic polymorphisms in the 11β-HSD1 gene have been associated with increased hepatic fat content. Specifically, the single nucleotide polymorphisms rs2235543, rs12565406, and rs4844880 strongly correlated with liver lipid levels[45]. Individuals homozygous for these alleles demonstrated nearly double the risk of developing MASLD, independent of total and visceral fat mass[45]. It is interesting to note that the activity of 11β-HSD1 varies along the spectrum of MASLD, with reduced activity in early phases of steatosis and increased activity in MASH patients[46], which could be a protective response to excess of cortisol in early phases, and indicates the need for a glucocorticoid anti-inflammatory effect to prevent steatohepatitis in the later phases[46]. The increasing evidence on the role of 11β-HSD1 in the metabolism of cortisol suggests it could be a potential therapeutic target. Several 11β-HSD1 inhibitors have been developed and are under investigation (Table 2)[47]. A phase 2 randomized, double-blind, placebo-controlled trial of the 11β-HSD1 inhibitor AZD4017 in patients with MASLD or MASH showed a reduction in liver fat fraction after 12 weeks. However, no differences were observed in fibrosis, weight, liver enzymes, or lipid levels[48]. This may have been due to the short trial duration and inclusion of both MASLD and MASH patients, as 11β-HSD1 activity may differ across the disease spectrum[46], although this was not confirmed by all studies[49]. In vitro studies have shown reduced 11β-HSD1 expression in hepatocytes from steatotic livers; possibly reflecting a compensatory mechanism to limit cortisol activity[46,50]. 11β-HSD1 inhibitor S-707106 has been studied in CS and patients with mild autonomous cortisol secretion[51]. The authors did not report any data regarding liver function or steatosis in these patients[51].

Table 2 List of preclinical studies and trial involving 11β-hydroxysteroid dehydrogenase type 1.

Compound	Study type	Subjects	Key findings related to liver	Potential indication	Ref.
J2H-1702	Preclinical study	Mice (high fat/high carbohydrate fed)	Decreased triglyceride levels in the liver	MASLD	[82]
INU-101	Preclinical study	Mice (fast-food diet model)	Reduced hepatic lipid accumulation and fibrosis	MASLD and liver fibrosis	[43]
J2H-1702	Preclinical study	Mice (NASH models)	Reduced lipid accumulation and fibrosis	MASH	[41]
BVT2733	Preclinical study	Mice (high fat diet)	Decrease in body weight, better glucose tolerance, reduced inflammation	Obesity-related liver disease	[83]
AZD6925	Preclinical study	Mice	Prevented hepatic steatosis and reduced liver triglycerides levels	MASLD	[84]
BI 135585	Single-dose study and double blind, placebo controlled clinical trial	Healthy volunteers (single dose) and patients with type 2 diabetes	Demonstrated liver 11β-HSD1 inhibition	MASLD in T2D	[85]
BI 187004	Randomized, double-blind, placebo-controlled	Patients with T2D and obesity	Near-full liver 11β-HSD1 inhibition	Liver-related metabolic disorders	[86]
J2H-1702	Randomized, double blinded, placebo-controlled trial	Healthy volunteers	Effectively reduced 11β-HSD1 activity	NASH	[87]
RO5093151	Phase 1b trial. Multicenter, randomized, double-blind, placebo-controlled trial	MASLD patients	Significantly reduced liver-fat content vs placebo	MASLD	[88]
AZD4017	Phase II, randomized, double-blind, placebo-controlled study	NASH or MASLD patients	Reduced conversion of cortisone to cortisol. Able to find a significant difference in reduction of liver fat fraction only in patients with NASH and T2D	MASH with T2D	[48]

MASLD: Metabolic dysfunction-associated steatotic liver disease; NASH: Non-alcoholic steatohepatitis; MASH: Metabolic dysfunction associated steatohepatitis; 11β-HSD1: 11β-hydroxysteroid dehydrogenase type 1; T2D: Type 2 diabetes.

ROLE OF 5Α-REDUCTASE AND 5Β-REDUCTASE

In addition to 11β-HSD1, 5α-reductase and 5β-reductase have been investigated in the pathogenesis of MASLD (Figure 1B)[52]. They are key enzymes in the metabolism of both cortisol and testosterone. 5α-Reductase converts testosterone into its more potent form dihydrotestosterone[53]. These enzymes catalyze the irreversible A-ring reduction of cortisol and other glucocorticoids, leading to the formation of 5α- and 5β-dihydro metabolites, respectively. This process represents the major pathway for glucocorticoid inactivation in the liver and peripheral tissues. 5α-Reduced glucocorticoid metabolites can retain some glucocorticoid receptor activity, whereas 5β-reductase (AKR1D1) generates 5β-reduced metabolites (5β-dihydrocortisol and 5β-tetrahydrocortisol) that are biologically inactive. These enzymes regulate the metabolic clearance rate of cortisol and modulates tissue-specific glucocorticoid exposure. 5α-Reductase is expressed in types 1 and 2. Type 1 is principally expressed in metabolic tissues while type 2 in the reproductive tract[51]. Therefore, metabolic effects appear to be principally mediated by 5α-reductase type 1 while mutations in type 2 are principally linked to disorders of sexual development[54]. Although the first evidence of 5α-reductase activity in the liver came from its isolation in rat liver in the 1950s[55], only recently its role in liver disease progression has been explored. Loss of 5α-reductase type 1 5α-reductase type 1 (-/-) mice undergoing American lifestyle-induced obesity syndrome diet developed more steatosis compared to wild type and 5α-reductase type 2 (-/-) mice[56]. 5α-Reductase type 1 (-/-) mice had a 0% incidence of hepatocarcinoma after 12 months of American lifestyle-induced obesity syndrome diet compared to wild-type mice[56]. 5β-Reductase acts as a pre-receptor regulator of steroid hormones action as it metabolizes cortisol and other steroid hormones into inactive forms, 5β-reduced cortisol is unable to bind the glucocorticoid receptor[52,57]. The role of 5β-reductase in the setting of metabolic syndrome and MASLD has less evidence compared to 11β-HSD1 and 5α-reductase. In vitro studies on HepG2 cells showed that dexamethasone reduced 5β-reductase mRNA expression, consequently reducing cortisol clearance[58]. No effect of dexamethasone was seen on 5α-reductase and 11β-HSD2 mRNA expression[58]. In vitro studies with human liver cells showed that knockdown of 5β-reductase reduced bile acid biosynthesis and increased fat deposition in hepatocytes and glycogen synthesis[59]. Another study on obese rats showed increase in 5β-reductase mRNA, which was reversed after use of insulin sensitizer such as metformin and rosiglitazone[59]. 5β-Reductase activity on synthetic glucocorticoids (dexamethasone and prednisolone) appears to be lower compared to its activity on endogenous cortisol[58]. Nikolaou et al[59] investigated 5β-reductase mRNA in 34 obese patients that underwent liver biopsy. Progression of fibrosis was associated with reduced expression of 5β-reductase[59]. 5β-Reductase knockdown promotes lipid accumulation, increasing de novo lipogenesis and decreasing β-oxidation. The role of 5α-reductase inhibitors as potential drivers of hepatic steatosis has been studied[60,61]. Dual inhibitors such as dutasteride, have been linked to increased intrahepatic lipid accumulation, while exclusively type 5α-reductase inhibitors such as finasteride have no effect on hepatic steatosis[60,61]. In conclusion, 5α-reductase and 5β-reductase inactivate cortisol and glucocorticoids by producing metabolites with little or no receptor activity with potential effects on fatty liver disease (Table 3).

Table 3 Summary of the main enzymes involved in hepatic cortisol metabolism and their role in metabolic dysfunction-associated steatotic liver disease. The table highlights enzyme function, expression changes across disease stages, effects on hepatic steatosis, and potential therapeutic implications.

Enzyme	Primary function	Hepatic expression	Effects on hepatic steatosis	Possible therapeutic implications
11β-HSD1	Converts inactive cortisone to active cortisol; amplifies intracellular cortisol action	Reduced in early steatosis; increased in MASH	Overexpression promotes lipogenesis and fat accumulation; knockout protects against steatosis	Inhibition may provide reduction in liver steatosis
11β-HSD2	Inactivates cortisol to cortisone	Not extensively studied in MASLD	Primarily renal/placental function; limited hepatic role in MASLD	Not a primary therapeutic target at the moment for MASLD
5α-reductase type 1	Converts cortisol to 5α-dihydrocortisol (retains some GR activity); converts testosterone to DHT	Increased in steatosis	Deficiency/inhibition increases steatosis but protects against HCC; mediates metabolic effects	Dual inhibitors (dutasteride) increase hepatic lipid accumulation. Selective type 2 inhibitors (finasteride) have no effect on steatosis
5α-reductase type 2	Converts cortisol to 5α-dihydrocortisol; converts testosterone to DHT in reproductive tissues	Primarily reproductive tract expression	Minimal metabolic effects; deficiency does not increase steatosis	Limited metabolic relevance
5β-reductase (AKR1D1)	Converts cortisol to 5β-dihydrocortisol (biologically inactive); major cortisol inactivation pathway	Variable in early disease; reduced with progressive fibrosis	Knockdown promotes lipid accumulation via increased de novo lipogenesis	Increasing its activity may have a potential protective role

MASLD: Metabolic dysfunction-associated steatotic liver disease; 11β-HSD1: 11β-hydroxysteroid dehydrogenase type 1; MASH: Metabolic dysfunction associated steatohepatitis; 11β-HSD2: 11β-hydroxysteroid dehydrogenase type 2; GR: Glucocorticoid receptor; DHT: Dihydrotestosterone; HCC: Hepatocellular carcinoma.

KEY PATHWAYS IN CORTISOL-INDUCED LIPOGENESIS

Glucocorticoids increase the availability of glucose by stimulating gluconeogenesis and glycogenolysis by enhancing activity of enzymes involved in glucose metabolism, such as phosphoenolpyruvate carboxy kinase and glucose-6-phosphatase. Glucose, in turn, serves as a key substrate for de novo lipogenesis; the process by which fatty acids are synthesized from nonlipid precursors[7,8]. Cortisol can induce liver lipogenesis alone, but it is also mediated by its inhibitory effects on insulin action[7,34,62]. Increased availability of glucose and fatty acid absorption play a major role in the development of MASLD. CD36 is a multifunctional transmembrane protein that plays a key role in the absorption of long-chain fatty acids into cells and is significantly upregulated in patients with nonalcoholic steatohepatitis (NASH)[63,64]. Dexamethasone induces dose-dependent upregulation of CD36 in mouse hepatocytes[65]. Cortisol upregulates key lipogenic transcription factors such as sterol regulatory element-binding protein 1c (SREBP1) and carbohydrate-responsive element-binding protein. In Hep3B cells, expression of SREBP1 and carbohydrate-responsive element-binding protein increases proportionally with cortisol concentration[43]. SREBP1 expression is also upregulated in Hep1-6 cells transfected with an adenovirus containing 11β-HSD1; partly via downregulation of its inhibitor Insig2, mediated by increased levels of gp78, an E3 ubiquitin ligase[44]. Overexpression of 11β-HSD1 also upregulates fatty acid synthase, stearoyl-CoA desaturase 1, and acetyl-CoA carboxylase 1; all of which are transcription factors involved in lipogenesis[44]. Accumulation of ceramides is linked to inflammation and liver steatosis. Angiopoietin-like 4 is involved in ceramide production and is involved in dexamethasone-mediated liver adipogenesis[9]. Angiopoietin-like 4 null mice have lower levels of hepatic triglycerides after dexamethasone exposure[9]. FK506 binding protein 5 is considered the principal marker of cortisol action[66]. It has been shown to play an important role in insulin and glucose homeostasis[67]. A role of FK506 binding protein 5 upregulation has been suggested in the pathogenesis of alcoholic liver disease[68]. Its role in the development of MASLD needs further elucidation. Another pathway investigated is AMP-activated protein kinase (AMPK) phosphorylation. AMPK has a tissue-specific action, and is known to switch metabolism from anabolic to catabolic pathways, therefore reducing lipogenesis, and it is a known regulator of adipogenesis[69,70]. Cortisol and synthetic glucocorticoids are linked to a reduction in phosphorylated AMPK and reduced AMPK action[43,71]. MAP kinase phosphatase-3 (MPK3) appears to play a role in glucocorticoid-induced liver steatosis[72]. Dexamethasone exposure increases MPK3 expression, which is likely mediated by forkhead box protein O1[72]. Knockout mice for MPK3 are protected from accumulation of fat after dexamethasone exposure[72]. MPK3 knockout mice are also protected from insulin resistance and increased body weight[72]. Use of metformin in patients exposed to dexamethasone showed reduced liver enzymes in a double-blind randomized trial[73]. The authors suggested that metformin action could be mediated by the AMPK pathway[73]. Liraglutide increases AMPK phosphorylation and appears to reduce expression of CD36, which has a beneficial effect on both pathways[71]. Another pathway that has been explored is Kruppel-like factor 9 (Klf9). Dexamethasone-induced overexpression of Klf9 appears to be essential for glucocorticoid-induced obesity. Dexamethasone-induced Klf9 overexpression in macrophages leads to recruitment of the SIN3A/histone deacetylase complex to the promoters of interleukin-6, prostaglandin-endoperoxide synthase 2, chitinase-like protein 3, and arginase 1, determining a suppression of signal transducer and activator of transcription 3 signaling. This results in reduced thermogenesis and increased fat deposition[74]. The same group showed that dexamethasone-induced Klf9 overexpression in hepatocytes is linked to increased hepatic gluconeogenesis[75]. Another group showed increased hepatic weight in Klf9 knockout mice but no changes regarding liver lipid content[76].

CORTISOL METABOLISM AS A MARKER OF LIVER FUNCTION

Liver biopsy is the gold standard in the staging of MASLD severity; however, it is an invasive and costly tool that can be associated with complications. Therefore, there is a need for noninvasive markers of MASLD severity. Changes in hepatic cortisol metabolism could be a valuable prognostic marker in patients with liver disease. Alterations in cortisol metabolism have been observed across the spectrum of liver pathology. The regulation of 11β-HSD differs between patients with simple steatosis and those with MASH. In steatosis, a reduction in active cortisol levels has been reported, which may play a protective role by limiting further fat accumulation[46,50]. Conversely, patients with NASH tend to exhibit elevated cortisol levels, potentially reflecting an adaptive, anti-inflammatory response aimed at controlling hepatic inflammation[46].

Disturbances in cortisol metabolism have been associated with liver-related complications and increased mortality. For example, in a cohort study involving 78 patients, Michailidou et al[77] found that lower levels of cortisol clearance (< 55 μg/24 h) were associated with poorer prognostic outcomes. Westerbacka et al[50] found that patients with liver disease exhibited higher urinary excretion of 5β-reduced cortisol metabolites, which was associated with insulin resistance and hypertriglyceridemia. The urinary steroid metabolome has the potential to be a useful tool in the staging of liver pathology. Moolla et al[78] were able to distinguish between fibrosis stage (F1-F2/F3-F4) using machine-learning-based Generalised Matrix Learning Vector Quantisation analysis. The overall activity of 11β-HSD, as assessed by the urinary (tetrahydrocortisol + 5α-tetrahydrocortisol)/tetrahydrocortisone ratio and 11β-HSD1 mRNA expression, showed no significant difference between healthy lean subjects and patients with fatty liver or NASH[49]. These findings highlight the potential of urinary steroid profiling as a noninvasive tool for the diagnosis and stratification of patients with liver disease including hepatocarcinoma[79]. Recently the TrUSt-NAFLD study (trial registration number: ISRCTN19370855) was proposed[80]. It was a multicenter prospective study to evaluate the use of urine steroid metabolome to stage MASLD severity[80]. The ratio between dehydroepiandrosterone sulfate and cortisol has been shown to be a predictor of mortality in cirrhotic patients with septic shock[81]. A lower dehydroepiandrosterone sulfate/cortisol ratio is associated with more severe disease suggesting a hepatoadrenal syndrome[81].

CONCLUSION

CS appears to confer an increased risk of MASLD through both direct cortisol-mediated effects on hepatocytes and indirect mechanisms related to systemic metabolic dysfunction. However, available data on MASLD prevalence in this setting remain limited, largely retrospective, and predominantly based on imaging rather than histological assessment. As imaging endpoints are only surrogate markers of disease severity, prospective studies incorporating liver histology and longitudinal follow-up are needed to better define the natural history and clinical burden of MASLD in patients with hypercortisolism.

Beyond its pathogenic role, cortisol metabolism is increasingly recognized as a clinically relevant biomarker of liver function and disease progression. Alterations in hepatic steroid handling reflect both disease stage and prognosis, supporting the concept that the liver actively shapes systemic glucocorticoid exposure. In this context, urinary steroid metabolomics offers a promising, noninvasive approach for disease stratification, risk prediction, and potentially treatment monitoring in MASLD. With ongoing studies such as TrUSt-NAFLD, cortisol-related biomarkers may soon find translational application in routine clinical practice, aiding personalized risk assessment and improving the management of patients with MASLD, particularly in those with disorders of cortisol excess.