Association between Serum Testosterone Levels and Body Composition among Men 20-59 Years of Age

Effects of testosterone and vitamin D on fall risk in pre-frail hypogonadal men: a factorial design RCT

OBJECTIVE

To test whether transdermal testosterone at a dose of 75 mg per day and/or monthly 24'000 IU Vitamin D reduces the fall risk in pre-frail hypogonadal men aged 65 and older.

DESIGN

2 × 2 factorial design randomized controlled trial, follow up of 12 months.

METHODS

Hypogonadism was defined as total testosterone <11.3 nmol/L and pre-frailty as ≥1 Fried- frailty criteria and/or being at risk for falling at the time of screening. The primary outcomes were number of fallers and the rate of falls, assessed prospectively. Secondary outcomes were appendicular lean mass (ALM), sit-to-stand, gait speed, and the short physical performance test battery. Analyses were adjusted for age, BMI, fall history and the respective baseline measurement.

RESULTS

We aimed to recruit 168 men and stopped at 91 due to unexpected low recruitment rate (1266 men were pre-screened). Mean age was 72.2 years, serum total testosterone was 10.8 ± 3.0 nmol/l, and 20.9% had 25(OH)D levels below 20 ng/mL. Over 12 months, 37 participants had 72 falls. Neither the odds of falling nor the rate of falls were reduced by testosterone or by vitamin D. Testosterone improved ALM compared to no testosterone (0.21 kg/m2 [0.06, 0.37]), and improved gait speed (0.11 m/s, [0.03, 0.20]) compared to placebo.

CONCLUSION

Transdermal testosterone did not reduce fall risk but improved ALM and gait speed in pre-frail older men. Monthly vitamin D supplementation had no benefit.

Roles of sex hormones in mediating the causal effect of vitamin D on osteoporosis: A two-step Mendelian randomization study

Background

Although 25-hydroxyvitamin D [25(OH)D] is a risk factor for osteoporosis, it is not clear whether sex hormones mediate this casual association. We aimed to explore how sex hormones affect the association between 25(OH)D and osteoporosis to provide meaningful insights on the underlying mechanisms from a genetic perspective.

Methods

Genetic variations in 25(OH)D, total testosterone (TT), androstenedione (A4), estradiol (E2), and testosterone/17β-estradiol (T/E2) were determined through summary statistics. Taking osteoporosis as the outcome (FinnGen biobank, 332,020 samples), we conducted a Mendelian randomization (MR) analysis to establish the association between 25(OH)D and these sex hormones. The two-step MR analysis quantified the mediatory effects of sex hormones on osteoporosis. The results were further verified by pleiotropy and heterogeneity analyses.

Results

MR results showed that 25(OH)D (OR= 1.27, p = 0.04) and TT (OR= 1.25, p = 0.04) had a causal effect on osteoporosis. No significant associations were observed between the other sex hormones (A4, E2, and T/E2) and osteoporosis (p&gt;0.05). Sensitivity analysis (p&gt;0.05) confirmed the robustness of the MR results. The two-step MR analysis provided evidence that the mediatory effect of TT was 0.014 (the percentage of TT mediation was 5.91%). Moreover, the direct effect of 25(OH)D on osteoporosis was 0.221. A4, E2, and T/E2 were not considered as potential mediators of the role of 25(OH)D as a risk factor for OP.

Conclusion

This study, through MR analysis, showed that TT mediates the causal effect of 25(OH)D on osteoporosis. Interventions targeting TT, therefore, have the potential to substantially reduce the burden of osteoporosis attributable to high 25(OH)D.

Higher serum apolipoprotein B level will reduce the bone mineral density and increase the risk of osteopenia or osteoporosis in adults

Objective: There is very limited evidence in the NHANES database linking serum apolipoprotein B and lumbar bone mineral density (BMD) in adults aged 20-59 years. There are few studies associating apolipoprotein B concentrations with BMD, and there is some debate about the association between obesity and BMD. Therefore, the purpose of this study was to determine the association between serum apolipoprotein B concentrations and lumbar spine BMD in adults aged 20-59 years and to predict its association with risk of osteopenia or osteoporosis. Methods: A cross-sectional study of the entire US ambulatory population was conducted using data from the National Health and Nutrition Examination Survey (NHANES) database. Weighted multiple regression equation models were used to assess the association between serum apolipoprotein B and lumbar BMD. A logistic weighted regression model was used to assess the association between serum apolipoprotein B concentrations and risk of osteopenia or osteoporosis. Subsequent stratified analyses were performed to refine the primary population of association. Results: Our study showed a significant negative association between serum apolipoprotein B concentration and lumbar BMD and a significant positive association with the risk of osteoporosis or osteopenia in the total population. After stratifying by sex, age and race, we concluded differently. The association of serum apolipoprotein B concentration with lumbar spine BMD and risk of osteopenia or osteoporosis was significant in male, but not in female. After stratification by age, the negative association between serum apolipoprotein B concentrations and lumbar BMD and the positive association with risk of osteopenia or osteoporosis was more significant in the 30-39 and 50-59 years age groups. When stratified by race, serum apolipoprotein B concentrations were significantly negatively associated with lumbar BMD and positively associated with risk of osteopenia or osteoporosis in Mexican American and non-Hispanic black populations. Thus, these findings suggest that these associations are influenced by sex, age, and race, respectively. Conclusion: Our results suggest that the association between serum apolipoprotein B levels and the risk of lumbar BMD and osteopenia or osteoporosis varies by sex, age, and race. In men, elevated serum apolipoprotein B levels were negative for bone quality. Elevated serum apolipoprotein B levels in the age groups 30-39 and 50-59 years also had a negative effect on bone quality. In the Mexican American and Non-Hispanic Black populations, elevated serum apolipoprotein B levels also had a significant negative effect on bone quality.

Protection against Osteoarthritis Symptoms by Aerobic Exercise with a High-Protein Diet by Reducing Inflammation in a Testosterone-Deficient Animal Model

A testosterone deficiency potentially increases osteoarthritis (OA) symptoms, and dietary protein and exercise affect them. However, their efficacy and their interactions are still unclear. We hypothesized that a high-protein diet (HPD) and regular exercise modulated OA symptoms in testosterone-deficient rats, and it was examined in bilateral orchidectomized (ORX) and monoiodoacetate (MIA)-injected rats. The ORX rats were given a 30 energy percent (En%) protein (HPD) or 17.5 En% protein (CD). Both groups had 39 En% fat in the diet. Non-ORX-CD rats (sham-operation of ORX) were given the CD and no exercise (normal control). After an eight-week intervention, all rats had an injection of MIA into the left knee, and the treatments were continued for an additional four weeks. The non-ORX-CD rats showed a significant increase in body weight compared to the ORX rats, but the ORX rats had elevated fat mass. ORX exacerbated the glucose tolerance by lowering the serum insulin concentrations and increasing insulin resistance. ORX exacerbated the OA symptoms more than the non-ORX-CD. The HPD and exercise improved bone mineral density and glucose metabolism without changing serum testosterone concentrations, while only exercise increased the lean body mass and decreased fat mass, lipid peroxide, and inflammation. Exercise, but not HPD, reduced the OA symptoms, the weight distribution in the left leg, and running velocity and provided better relief than the non-ORX-CD rats. Exercise with HPD improved the histology of the knee joint in the left leg. Exercise reduced lipid peroxide contents and TNF-α and IL-1β mRNA expression in the articular cartilage, while exercise with HPD decreased MMP-3 and MMP-13 mRNA expression as much as in the non-ORX-CD group. In conclusion, moderate aerobic exercise with HPD alleviated OA symptoms and articular cartilage degradation in a similar way in the non-ORX rats with OA by alleviating inflammation and oxidative stress.

Quercetin Attenuates Osteoporosis in Orchiectomy Mice by Regulating Glucose and Lipid Metabolism via the GPRC6A/AMPK/mTOR Signaling Pathway

Quercetin, a flavonoid found in natural medicines, has shown a role in disease prevention and health promotion. Moreover, because of its recently identified contribution in regulating bone homeostasis, quercetin may be considered a promising agent for improving bone health. This study aimed to elucidate the role of quercetin in androgen deprivation therapy-induced osteoporosis in mice. C57BL/6 mice were subjected to orchiectomy, followed by quercetin treatment (75 and 150 mg/kg/d) for 8 weeks. Bone microstructure was then assessed by micro-computed tomography, and a three-point bending test was used to evaluate the biomechanical parameters. Hematoxylin and eosin (H&E) staining was used to examine the shape of the distal femur, gastrocnemius muscle, and liver. The balance motion ability in mice was evaluated by gait analysis, and changes in the gastrocnemius muscle were observed via Oil red O and Masson's staining. ELISA and biochemical analyses were used to assess markers of the bone, glucose, and lipid metabolism. Western blotting analyses of glucose and lipid metabolism-related protein expression was performed, and expression of the GPCR6A/AMPK/mTOR signaling pathway-related proteins was also assessed. After 8 weeks of quercetin intervention, quercetin-treated mice showed increased bone mass, bone strength, and improved bone microstructure. Additionally, gait analysis, including stride length and frequency, were significantly increased, whereas a reduction of the stride length and gait symmetry was observed. H&E staining of the gastrocnemius muscle showed that the cross-sectional area of the myofibers had increased significantly, suggesting that quercetin improves balance, motion ability, and muscle mass. Bone metabolism improvement was defined by a reduction of serum levels of insulin, triglycerides, total cholesterol, and low-density lipoprotein, whereas levels of insulin-like growth factor-1 and high-density lipoprotein were increased after quercetin treatment. Expression of proteins involved in glucose uptake was increased, whereas that of proteins involved in lipid production was decreased. Moreover, the GPRC6A and the phospho-AMPK/AMPK expression ratio was elevated in the liver and tibia tissues. In contrast, the phospho-mTOR/mTOR ratio was reduced in the quercetin group. Our findings indicate that quercetin can reduce the osteoporosis induced by testosterone deficiency, and its beneficial effects might be associated with the regulation of glucose metabolism and inhibition of lipid metabolism via the GPCR6A/AMPK/mTOR signaling pathway.

Association between Serum Total Testosterone Level and Bone Mineral Density in Middle-Aged Postmenopausal Women

BACKGROUND

Hormone status strongly affects women's health and quality of life. To date, studies investigating the association between total testosterone (T) level and bone mineral density (BMD) in women are limited and have yielded contradictory conclusions. The aim of our study was to examine the association between serum total T level and lumbar BMD in postmenopausal women aged 40-59 years.

METHODS

The study group included 1,058 women from the 2011-2016 National Health and Nutrition Examination Survey. Multiple regression analyses were used to evaluate the association between serum total T level and lumbar BMD.

RESULTS

After adjusting for covariates, there was a positive association between the serum total T level and lumbar BMD (β, 1.07; 95% confidence interval, 0.17-1.97). A non-linearity in this association was identified, with a point of inflection at 30 ng/dL.

CONCLUSIONS

Serum total T level was positively associated with lumbar BMD in middle-aged postmenopausal women up to a T level >30 ng/dL. Therefore, increasing T level in women with a low serum total T level may have beneficial outcomes on bone health.