Testosterone therapy reduces hepatic steatosis in men with type 2 diabetes and low serum testosterone concentrations

Sexual dimorphism of metabolic dysfunction-associated steatotic liver disease

Metabolic dysfunction-associated steatotic liver disease (MASLD) is the most common chronic liver condition. MASLD is a sexually dimorphic condition, with its development and progression influenced by sex chromosomes and hormones. Estrogens typically protect against, whereas androgens promote, MASLD. Therapeutic approaches for a sex-specific personalized medicine include estrogen replacement, androgen blockers, and novel drugs targeting hormonal pathways. However, the interactions between hormonal factors and inherited genetic variation impacts MASLD risk, necessitating more tailored therapies. Understanding sex disparities and the role of estrogens could improve MASLD interventions and management, whereas clinical trials addressing sex differences are crucial for advancing personalized treatment. This review explores the underappreciated impact of sexual dimorphism in MASLD and discusses the potential therapeutic application of sex-related hormones.

Hypogonadism and nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD), recently proposed to be renamed to metabolic dysfunction-associated steatotic liver disease (MASLD), is a major global public health concern, affecting approximately 25-30% of the adult population and possibly leading to cirrhosis, hepatocellular carcinoma, and liver transplantation. The liver is involved in the actions of sex steroids via their hepatic metabolism and production of the sex hormone-binding globulin (SHBG). Liver disease, including NAFLD, is associated with reproductive dysfunction in men and women, and the prevalence of NAFLD in patients with hypogonadism is considerable. A wide spectrum of possible pathophysiological mechanisms linking NAFLD and male/female hypogonadism has been investigated. As therapies targeting NAFLD may impact hypogonadism in men and women, and vice versa, treatments of the latter may affect NAFLD, and an insight into their pathophysiological pathways is imperative. This paper aims to elucidate the complex association between NAFLD and hypogonadism in men and women and discuss the therapeutic options and their impact on both conditions.

Noninvasive Indices of MASLD Are Associated With Hypogonadism in Male Patients With Type 2 Diabetes Mellitus

CONTEXT

Metabolic dysfunction-associated steatotic liver disease (MASLD) is the most prevalent chronic liver disease, affecting one-fourth of the adult population worldwide. Recent data found an association between MASLD and hypogonadism, but this relation in patients with type 2 diabetes mellitus (T2DM) is still unclear.

OBJECTIVE

To evaluate in men with T2DM the association between total testosterone (TT) and noninvasive indices of hepatic steatosis (Fatty Liver Index [FLI], Hepatic Steatosis Index [HSI], Dallas Steatosis Index [DSI]) and fibrosis (AST to Platelet Ratio Index [APRI], Fibrosis-4 Index [FIB-4]), and their predictive cutoff values in identifying hypogonadism.

METHODS

Cross-sectional study on 189 men with T2DM, without history of liver diseases and alcoholism, recruited on an outpatient basis. Interventions were andrological evaluation, metabolic parameters, TT, and liver indices. The main outcome measures were comparison of steatosis and fibrosis indices with testosterone levels and presence of hypogonadism. Receiver operating characteristic curves were used to identify cutoff values of liver indices in predicting low testosterone (<12 nmol/L).

RESULTS

FLI, HSI, and DSI were negatively related with TT and were higher in the low-testosterone group than in the normal-testosterone group (FLI: 74.1 [61.4-93.5] vs 56.5 [32.1-78.2], P < .001; HSI: 41.5 [39.2-45.9] vs 40.1 [36.6-43.2], P = .005; DSI: 0.45 [-0.08-+1.04] vs -0.07 [-1.02-+0.58], P < .001). FLI and DSI also correlated with clinical symptoms of hypogonadism. No differences between groups were observed for APRI and FIB-4. FLI ≥63 was the best parameter as predictive index of low TT (sensitivity 73%, specificity 64%).

CONCLUSION

We found an association between noninvasive indices of steatosis and hypogonadism in patients with T2DM. These indices could be used to direct the patients to andrological evaluation.

The Effect of Testosterone Replacement Therapy on Nonalcoholic Fatty Liver Disease in Older Hypogonadal Men

CONTEXT

Male hypogonadism is associated with visceral obesity and the metabolic syndrome: factors important for the development of nonalcoholic fatty liver disease (NAFLD). The Testosterone Trials (The T Trials) showed testosterone (T) treatment compared with placebo in older hypogonadal men was associated with decreases in cholesterol and insulin levels suggesting that T treatment may improve NAFLD.

OBJECTIVE

Compare effects of T vs placebo treatment on NAFLD scores and liver scans in elderly hypogonadal men.

METHODS

Secondary data analyses from 479 older hypogonadal men with total T < 275 ng/dL from The T Trials were performed. Three clinical liver fat scores-lipid accumulation product index, hepatic steatosis index, nonalcoholic fatty liver disease-metabolic syndrome score-and liver computed tomography (CT) Hounsfield units and liver to spleen ratio were evaluated at baseline and 12 months after treatment.

RESULTS

There were no statistically significant differences of change in lipid accumulation product index (P = .98), hepatic steatosis index (P = .67), and nonalcoholic fatty liver disease-metabolic syndrome (P = .52) in 246 men treated with T compared with 233 treated with placebo for 12 months. Liver CT showed no statistically significant difference of change in Hounsfield units (P = .24; n = 71 for T, n = 69 for placebo) and liver to spleen ratio (P = .74; n = 55 for T, n = 62 for placebo) between the 2 groups.

CONCLUSIONS

Our study did not show improvement of NAFLD in older hypogonadal men after 12 months of T vs placebo treatment, as assessed by 3 clinical scores and liver CT for hepatic steatosis. Future studies with longer treatment duration and additional NAFLD diagnostic modalities as primary outcome are warranted.

Maternal obesity impacts fetal liver androgen signalling in a sex-specific manner

BACKGROUND

Maternal obesity (MO) increases fetal androgen concentrations, the prevalence of macrosomia, and predisposes offspring to metabolic dysfunction in later life, especially males. These risks may be, in part, the result of increased liver-specific androgen signalling pathway activity in utero. Androgen signalling activity can be suppressed by androgen metabolism via cytochrome P450 (CYP) isoenzymes (CYP2B6, CYP3A) or through inhibition of the full-length androgen receptor (AR-FL) via the antagonistic isoform, AR-45. We hypothesised MO impairs CYP enzyme activity and AR-45 expression in male fetal livers, thereby enhancing activity of androgen signalling pathways.

METHODS

Nine months prior to pregnancy, nulliparous female baboons were assigned to either ad libitum control or high fat diet. At 165 day (d) gestation (term, 180 d) fetal liver was collected (n = 6/sex/group). CYP activity was quantified using functional assays; subcellular AR expression was measured using Western blot.

RESULTS

CYP2B6 and CYP3A activity, and nuclear expression of AR-45, was reduced in MO males only. Nuclear AR-45 expression was inversely related with fetal body weight of MO males only.

CONCLUSIONS

Reduced CYP2B6 and CYP3A activity in conjunction with decreased nuclear AR-45 expression may enhance liver androgen signalling in males from MO pregnancies, thereby increasing the risk of macrosomia, as well as metabolic dysfunction in later life.

Metabolic dysfunction-associated fatty liver disease is an early predictor for testosterone deficiency in aging men without metabolic syndrome

Background and aims

Metabolic dysfunction-associated fatty liver disease (MAFLD) has emerged as a valuable marker for identifying individuals at increased risk of metabolic dysfunction, liver-related complications, and cardiovascular disease. However, the association between MAFLD and testosterone deficiency (TD) in aging men remains poorly understood. This study aimed to investigate the association between MAFLD and the risk of TD in aging Taiwanese men, with a specific focus on those without metabolic syndrome (MetS).

Methods

A free health screening program was conducted for Taiwanese men aged over 40 years in Kaohsiung, Taiwan. Participants underwent physical examinations, completed questionnaires regarding demographics, medical history, and clinical symptoms of TD, and provided 20-mL whole blood samples for biochemical, adipocytokine, and hormonal evaluations. Fatty liver index was used to evaluate the risk of fatty liver. Diagnostic criteria for MAFLD included fatty liver along with overweight/obesity, type 2 diabetes, or evidence of metabolic dysregulation.

Results

A total of 631 men (mean age: 54.4 ± 8.4 years) were enrolled. The prevalence rates of TD and MetS were significantly higher in men with MAFLD compared to those without (both p < 0.001). Additionally, the presence of MAFLD showed a significant correlation with adipocytokines associated with insulin resistance, such as adiponectin, leptin, and retinol-binding protein-4 (RBP-4) levels (all p < 0.001). Among men without MetS, those with MAFLD had a 3.89- and 4.74-fold higher risk of total testosterone < 300 ng/dL and TD, respectively, after adjusting for potential covariates.

Conclusion

MAFLD is associated with an elevated risk of TD in aging Taiwanese men, particularly in the absence of MetS. This finding suggests that MAFLD could serve as an early predictor of TD, facilitating the identification of high-risk individuals and enabling timely interventions. Further research is needed to validate these findings and explore the underlying mechanisms linking MAFLD, TD, and MetS in diverse populations.

Testosterone is lower in men with non-alcoholic fatty liver disease and alcohol-related cirrhosis and is associated with adverse clinical outcomes

BACKGROUND/AIMS

Low serum testosterone is common in cirrhotic men, but the impact of disease aetiology remains uncertain. This study compares serum total testosterone (TT) levels by disease aetiology and assesses its prognostic value.

METHODS

Single-centre retrospective study of cirrhotic men who had TT levels measured between 2002 and 2020. A cut-off of 12 nmol/L was used to define low TT and 230 pmol/L for calculated free testosterone (cFT). Linear and logistic regression used to adjust for variables known to affect testosterone levels and assess for an association between levels and outcomes.

RESULTS

Of 766 cirrhotic men, 33.3% had alcohol-related liver disease (ALD) and 11.9% had non-alcoholic fatty liver disease (NAFLD). The median age was 56 years (interquartile range (IQR) 50-61), and the model for end-stage liver disease (MELD) score 14 (IQR 9-20). TT levels were low in 53.3% of patients, (median 11.0 nmol/L; IQR 3.7-19.8) and cFT low in 79.6% (median 122 pmol/L; IQR 48.6-212). Median TT was lower in men with ALD (7.6 nmol/L; IQR 2.1-16.2) and NAFLD (9.8 nmol/L; IQR 2.75-15.6) compared to other aetiologies (11.0 nmol/L; IQR 3.73-19.8) (p < 0.001 for all), which remained true after adjustment for age and MELD score. TT was inversely associated with 12-month mortality or transplant (381 events, p = 0.02) and liver decompensation (345 events, p = 0.004).

CONCLUSIONS

Low serum testosterone is common in cirrhotic men and is associated with adverse clinical outcomes. TT levels are significantly lower in ALD and NAFLD compared to other disease aetiologies. Further large-scale studies are required to assess the potential benefits of testosterone therapy.

The Influence of Sex Hormones in Liver Function and Disease

The liver performs a multitude of bodily functions, whilst retaining the ability to regenerate damaged tissue. In this review, we discuss sex steroid biology, regulation of mammalian liver physiology and the development of new model systems to improve our understanding of liver biology in health and disease. A major risk factor for the development of liver disease is hepatic fibrosis. Key drivers of this process are metabolic dysfunction and pathologic activation of the immune system. Although non-alcoholic fatty liver disease (NAFLD) is largely regarded as benign, it does progress to non-alcoholic steatohepatitis in a subset of patients, increasing their risk of developing cirrhosis and hepatocellular carcinoma. NAFLD susceptibility varies across the population, with obesity and insulin resistance playing a strong role in the disease development. Additionally, sex and age have been identified as important risk factors. In addition to the regulation of liver biochemistry, sex hormones also regulate the immune system, with sexual dimorphism described for both innate and adaptive immune responses. Therefore, sex differences in liver metabolism, immunity and their interplay are important factors to consider when designing, studying and developing therapeutic strategies to treat human liver disease. The purpose of this review is to provide the reader with a general overview of sex steroid biology and their regulation of mammalian liver physiology.

Association of non-alcoholic fatty liver disease with total testosterone in non-overweight/obese men with type 2 diabetes mellitus

PURPOSE

Non-alcoholic fatty liver disease (NAFLD) is considered as both a vital risk factor and a consequence of type 2 diabetes mellitus (T2DM). Low total testosterone (TT) is common in men with T2DM, contributing to increased risks of metabolic diseases. This study aimed to investigate the association between TT levels and the prevalence of NAFLD in men with T2DM.

METHODS

In this cross-sectional study, 1005 men with T2DM were enrolled in National Metabolic Management Center (MMC) of First Affiliated Hospital of Wenzhou Medical University between January 2017 and August 2021. NAFLD was diagnosed using ultrasound as described by the Chinese Liver Disease Association. Overweight/obesity was defined as body mass index (BMI) ≥ 25 kg/m² according to WHO BMI classifications.

RESULTS

Individuals without NAFLD had higher serum TT levels than those with NAFLD. After adjustments for potential confounding factors, the top tertile was significantly associated with lower prevalence of NAFLD compared with the bottom tertile of TT level [odds ratio (OR) 0.303, 95% confidence interval (CI) 0.281-0.713; P < 0.001]. The association between TT with NAFLD in individuals with normal weight (OR 0.175, 95% CI 0.098-0.315; P < 0.001) was stronger than in individuals with overweight/obesity (OR 0.509, 95% CI 0.267-0.971; P = 0.040). There was a significant interaction of TT with overweight/obesity (P for interaction = 0.018 for NAFLD).

CONCLUSION

Higher serum TT was significantly associated with a lower prevalence of NAFLD in men with T2DM. We found that the relationship of TT and NAFLD was stronger in individuals with non-overweight/obesity.

The associations of total testosterone with probable nonalcoholic steatohepatitis and nonalcoholic fatty liver disease fibrotic progression in men with type 2 diabetes: a cross-sectional study

BACKGROUND

Testosterone has an impact on metabolic disorders and men with type 2 diabetes mellitus (T2DM) are predisposed to hypogonadism; meanwhile, patients with T2DM have higher risk of NAFLD. Therefore, we speculate that testosterone may affect the progression of NAFLD in T2DM patients and we aim to investigate whether total testosterone is associated with NAFLD progression in men with T2DM.

METHODS

A cross-sectional study. A total of 1782 male participants with T2DM were enrolled from seven communities in Shanghai. Probable nonalcoholic steatohepatitis (NASH) was defined by the concurrence of NAFLD and metabolic syndrome (MetS). NAFLD fibrosis score was used to identify patients with probable advanced fibrosis. Multinomial logistic regression and ordinal logistic regression was used to measure the association of total testosterone (independent variable) and the progression category of NAFLD (dependent variable).

RESULTS

In male, TT quartiles were negatively associated with probable NASH (Q1 vs. Q4 OR 2.07 95% CI 1.31-3.28, P for trend = 0.001) and inflammatory progression of NAFLD with OR of 1 SD increment of ln (TT) 0.81 (95% CI 0.72-0.92, P for trend < 0.001), but positively with fibrotic progression (Q1 vs. Q4 OR 0.45, 95% CI 0.29-0.72, P for trend = 0.001) with OR of 1 SD increment of ln (TT) 1.24 (95% CI 1.07-1.45). According to stratified analyses, for inflammatory progression, the interactions of age strata, duration of diabetes strata, and dyslipidemia status with 1 SD increment of ln (TT) were significant (P for interaction 0.007, 0.003, and 0.012, respectively); as for fibrotic progression, we found no interactions (all P for interaction ≥ 0.05).

CONCLUSIONS

Different associations between TT and inflammatory and fibrotic progression of NAFLD in male were observed, suggesting different roles of TT in inflammatory and fibrotic stages of NAFLD.