Inverse association between serum bilirubin level and testosterone deficiency in middle-aged and older men

Positive association between serum bilirubin within the physiological range and serum testosterone levels

BACKGROUNDS

Research has demonstrated that elevated serum total bilirubin (STB) levels have a beneficial impact on various diseases, particularly metabolic syndrome. This study aims to investigate the association between STB levels and serum testosterone (STT) in order to determine if bilirubin plays a protective role in relation to testosterone deficiency (TD) risk.

METHODS

In this study, a total of 6,526 eligible male participants aged 20 years or older were analyzed, all of whom took part in the National Health and Nutrition Examination Survey (NHANES) conducted between 2011 and 2016. To investigate the relationship between STB and STT levels, we employed weighted multivariate regression models along with restricted cubic splines (RCS). Additionally, a subgroup analysis was conducted to explore the heterogeneity of this relationship across different subpopulations.

RESULTS

Among the participants, 1,832 individuals (28.07%) were identified as having testosterone deficiency (TD), defined as an STT level below 300 ng/dL. A significant positive correlation between STB and STT levels was observed in both crude and adjusted models (all P < 0.0001). The association between STB and STT levels was found to be statistically significant up to a threshold of 17.1 µmol/L, after which it became statistically insignificant(P for non-linearity = 0.0035). Weighted logistic regression analysis indicated that a 1 µmol/L increase in STB was associated with a 4% decrease in the likelihood of TD (odds ratio = 0.96, P < 0.0001). Subgroup analysis showed that the inverse relationship was limited to individuals aged 60 and over, non-smokers/drinkers, and obese individuals.

CONCLUSION

STB within the physiological range(17.1 µmol/L) was positively associated with STT in adult males. The potential protective role of bilirubin regarding testosterone levels merits further exploration.

Sex differences in the relationship between serum total bilirubin and risk of incident metabolic syndrome in community-dwelling adults: Propensity score analysis using longitudinal cohort data over 16 years

BACKGROUND

Research on identifiable risks for metabolic syndrome (MetS) is ongoing, and growing evidence suggests that bilirubin is a potent antioxidant and cytoprotective agent against MetS. However, there have been conflicting results on the association between bilirubin and MetS. Our study aimed to validate the association by separately stratifying data for men and women in a longitudinal prospective study.

METHODS

Data were derived from the Korean Genome Epidemiology Study provided by the Korea Centers for Disease Control and Prevention. Data from 5,185 adults aged 40-69 years (3,089 men and 2,096 women) without MetS were analyzed. The participants were divided according to sex-specific quartiles of serum total bilirubin levels and followed up biennially for 16 years (until 2018). The log-rank test was used for obtaining the Kaplan-Meier curves of cumulative incidence of MetS according to sex-specific serum total bilirubin quartiles, and the hazard ratios (HRs) with 95% confidence intervals (CIs) for incident metabolic syndrome were analyzed with a multiple Cox proportional hazard regression analysis model, after propensity score matching for removing differences at baseline.

RESULTS

With increasing serum total bilirubin quartiles, the incidence rate per 1000 person-years proportionally decreased in both men and women. After propensity score matching and adjusting for confounding variables, the HRs (95% CIs) for MetS of the highest quartile in reference to the lowest quartile were 1.00 (0.80-1.24) for men and 0.80 (0.65-0.99) for women. Higher quartiles of serum total bilirubin showed significantly lower cumulative incidence of MetS in women (log-rank test p = 0.009), but not in men (log-rank test p = 0.285).

CONCLUSION

Serum total bilirubin levels were significantly inversely associated with MetS in women, but there was no significant association observed in men. Sex differences in the effects of serum total bilirubin should be noted when predicting incident MetS by sex in clinical settings.

The sex life of male patients with cirrhosis and its organic factors: What we have got so far?

OBJECTIVE

The purpose of this study was to examine the sex lives of male cirrhotic patients organic factors affect them.

METHOD

We did an observational study of 220 cirrhotic men's satisfaction with their sexual lives. Assessment of sex satisfaction was carried out using the New Sexual Satisfaction Scale. The frequency of intercourse and masturbation was estimated. Then, the levels of albumin, total bilirubin, vitamin D, and sex steroids were examined. Ascites and sarcopenia subgroups of our patients were stratified.

RESULTS

Along with sex steroids, albumin, total bilirubin, and vitamin D all had an impact on how satisfying sex was (r = 0.22), (r = 0.24), and (r = -0.17) affected sex satisfaction. There were strong positive correlations between vitamin D (r = 0.33), albumin (r = 0.59), and free testosterone, along with a negative correlation between total bilirubin (r = -0.63) and free testosterone. An imbalance in sex steroid levels was observed, leading to decreased frequency of intercourse(p < 0.0001), weakened erections(p < 0.0001), and reduced quality of orgasm (p < 0.0001). Significant new sex behavior changes were found, such as an increase in masturbation. Physical limitations such as ascites and sarcopenia also impacted the decreasing sex life.

CONCLUSION

The sex life of cirrhotic men is affected. The decrease in the frequency of intercourse and sexual satisfaction is noticeable in male patients and leads to increased masturbation. Free Testosterone, vitamin D, albumin, and bilirubin play role in their sex life. In addition, ascites and sarcopenia not only affect their sex life but also hamper the quality of their well-being.

Relationship between serum indirect bilirubin levels and skeletal muscle mass in older male and female patients with type 2 diabetes

Objective

We previously showed that low serum bilirubin levels are associated with disability in quality of daily living in older patients with diabetes. However, the underlying mechanism is not fully understood. The aim of this study is to assess the relationship between serum bilirubin levels and skeletal muscle mass in older patients with type2 diabetes.

Methods

A total of 272 older patients with type2 diabetes (152 male and 120 female) aged 60 years and over were continuously recruited from April 2020 to July 2020. Body composition was evaluated by bioelectrical impedance analysis. The skeletal muscle mass index (SMI) was calculated as appendicular muscle mass divided by height squared (m²).

Results

The SMI was markedly lower in old-old patients (aged 75 years and over) than in young-old patients (aged 60–74 years) in both male and female (7.1 ± 0.8 kg/m² vs 7.6 ± 0.9 kg/m², P<0.001; 5.5 ± 0.9 kg/m² vs 6.3 ± 0.8 kg/m², P<0.001, respectively). Multivariate regression analysis showed that the SMI was associated with body mass index (BMI) (p<0.001) and age (p = 0.048) in male young-old patients, while it was associated with BMI (p<0.001), age (p = 0.008), and serum indirect bilirubin levels (p = 0.038) in male old-old patients. In female, the SMI was associated with BMI (p<0.001) and age (p = 0.042) in young-old patients and associated with BMI alone (p<0.001) in old-old patients.

Conclusion

Serum indirect bilirubin levels may be associated with the decreased skeletal muscle mass in male older patients (aged 75 years and over) with type 2 diabetes.