Association of total testosterone status with bone mineral density in adults aged 40–60 years

Objective Evidence linking total testosterone and bone mineral density (BMD) in adults is very limited. According to our review of the literature, only a few reports have focused on the relationship between total testosterone and bone mineral density in adults. Therefore, the purpose of this study was to determine the relationship between total testosterone and total bone mineral density in adults aged 40–60 years. Methods We used a cross-sectional study of a non-institutionalized U.S. population sample from the National Health and Nutrition Examination Survey. A weighted multivariate linear regression model was used to evaluate the relationship between total testosterone and total bone mineral density. Subgroup analyses were further performed. Results In multiple regression models adjusted for potential confounders, total testosterone levels were inversely associated with total bone mineral density. However, in the sex-stratified subgroup analysis, the association between total testosterone levels and total bone mineral density was not significant in female adolescents. There was no negative association between total testosterone and total BMD among men, adults 40 to 60 years of age, and other racial/ethnic groups. There is a negative association between total testosterone and total bone mineral density when total testosterone concentration is greater than 500 ng/dL among Non-Hispanic black. Conclusion Our statistical results show that the association between total testosterone levels and total bone mineral density varies by gender and race. Elevated total testosterone levels below 500 ng/dL have adverse effects on bone health. Total testosterone concentrations below 500 ng/dL may have no effect on bone health.

Bone Mineral Density Trends During the First Year After Laparoscopic Sleeve Gastrectomy—a Cohort Study on 241 Patients

Purpose Laparoscopic sleeve gastrectomy (LSG) is an effective weight loss procedure, but detrimental effects on bone health have been described. We aimed to assess the dynamics of regional and total bone mineral density (BMD) in a cohort of patients undergoing LSG and to capture gender differences in terms of evolution. Materials and Methods We conducted a retrospective study on 241 patients who underwent LSG to determine the regional and total BMD changes at 6 and 12 months after the intervention. Results One hundred ten males and 140 females (97 pre-, 43 postmenopausal) were included. Mean baseline body mass index (BMI) was 44.16 ± 6.11 kg/m2 in males and 41.60 ± 5.54 kg/m2 in females, reaching 28.62 ± 4.26 kg/m2 and 27.39 ± 4.2 kg/m2, respectively, at 12 months. BMD showed a continuous decline, with significant loss from 6 months postoperatively. There was a positive correlation between BMD and BMI decline at 12 months (r = 0.134, p < 0.05). Total BMD loss at 12 months was significantly greater in males than premenopausal females, independent of BMI variation and age. During the first 6 months, men lost significantly more bone mass than premenopausal and postmenopausal women (BMD variation was 2.62%, 0.27%, 1.58%, respectively). The second period (6–12 months) was similar in all three groups, revealing a further steady (~ 1.4%) BMD decline. Conclusions Our results are consistent with previous findings that LSG negatively impacts BMD, stressing the importance of bone health-oriented measures in postoperative care. Moreover, the impact that seems more significant in males warrants future exploration, as it might change clinical practice. Graphical abstract

Bone Mineral Reference Values for Athletes 11 to 20 Years of Age

Objectives. Training for sport is associated with the development of bone minerals, and the need for reference data based on athletes is often indicated. The purpose of this study was to develop a reference for bone mineral density (BMD) and content (BMC) specific for youth athletes of both sexes participating in several sports. Methods DEXA (dual energy X-ray absorptiometry) was used for total body measurements of bone minerals in 1385 athletes 11 to 20 years, 1019 males and 366 females. The athletes were training in several sports at Hungarian academies. Reference values for total bone mineral density and bone mineral content, and also BMD excluding the head (total body less head, TBLH) were developed using the LMS chartmaker pro version 2.3. Results. The centile distributions for BMD and BMC of the athletes differed significantly from those of the age- and sex-specific references for the general population. The youth athletes had higher BMD and BMC than those of the reference for the general population. Conclusion. The potential utility of the DEXA reference for male and female youth athletes may assist in monitoring changes in the BMC and BMD associated with normal growth and maturation, and perhaps more importantly, may be useful in monitoring changes specific to different phases of sport-specific training protocols.

Pedicle Screws Challenged: Lumbar Cortical Density and Thickness Are Greater in the Posterior Elements Than in the Pedicles

Study Design: Controlled laboratory study. Objective: To measure the total bone mineral density (BMD), cortical volume, and cortical thickness in seven different anatomical regions of the lumbar spine. Methods: Using computed tomography (CT) images, 3 cadaveric spines were digitally isolated by applying filters for cortical and cancellous bone. Each spine model was separated into 5 lumbar vertebrae, followed by segmentation of each vertebra into 7 anatomical regions of interest using 3-dimensional software modeling. The average Hounsfield units (HU) was determined for each region and converted to BMD with calibration phantoms of known BMD. These BMD measurements were further analyzed by the total volume, cortical volume, and cancellous volume. The cortical thickness was also measured. A similar analysis was performed by vertebral segment. St Mary’s Medical Center’s Institutional Review Board approved this study. No external funding was received for this work. Results: The lamina and inferior articular process contained the highest total BMD, thickest cortical shell, and largest percent volumes of cortical bone. The vertebral body demonstrated the lowest BMD. The BMDs of the L4 and L5 segments were lower; however, there were no statistically significant differences in BMD between the L1-L5 vertebral segments. Conclusion: Extrapedicular regions of the lumbar vertebrae, including the lamina and inferior articular process, contain denser bone than the pedicles. Since screw pullout strength relies greatly on bone density, the lamina and inferior articular processes may offer stronger fixation of the lumbar spine.

Effect of ovariectomy on proximal tibia metaphysis and lumbar vertebral body in common marmoset monkeys

This study aimed to investigate the effect of estrogen withdrawal on bone tissue in adult female marmoset monkeys. In a 1-year follow-up study we used quantitative computer tomography to measure total bone mineral density (BMD) of the proximal tibia and the second-last lumbar vertebral body (L5/L6) before and 1, 3, 6, and 12 months after ovariectomy. Body mass did not significantly change during the 1-year observation period. However, a significant decline of total BMD after ovariectomy was observed in the proximal tibia but not in L5/L6. In addition, regression analysis showed a significant positive relationship between BMD and body mass in both tibia and L5/L6. The results of our study support the idea that ovariectomized marmoset monkeys may serve as a model to investigate bone loss related to decline of estrogen production.

Abstract P615: Stress-Induced Changes in Total Bone Mineral Content and Total Bone Mineral Density due to Activation of the Renin-Angiotensin-Aldosterone System in Adolescent Females

Background: Previous literature has shown a strong negative effect of angiotensin II (ANGII) on bone metabolism within mouse models. Additionally, psychological stress has been associated with activation of the renin-angiotensin-aldosterone system (RAAS). Stress has also been related to lower total bone mineral density (TBMD). However, there is controversy in the literature examining the relationship between the RAAS and bone metabolism within humans and stress has not been considered as a direct link between these systems. Purpose: We aimed to examine the relationship between stress-induced RAAS activation and TBMD and total bone mineral content (TBMC). Methods: Participants were placed on a sodium controlled diet for three days. Participants then underwent two hours rest, one hour mental stressor, and two hours recovery with hourly collections of blood/urine samples. Renin, ANGII, aldosterone, TBMD and TBMC were measured. Results: This study recruited 586 adolescents (mean age 16±1.116) with 51% women and 62% African-American and 38% Caucasian. Overall, relationships were observed between ANGII and aldosterone, and TBMC and TBMD controlling for age, race, and BMI. During stress, aldosterone was related to TBMD (r=-.150, p<0.05) and ANGII was related to TBMC (r=-.156, p<0.05) and TBMD (r=-.139, p<0.05). When comparing males and females, only females demonstrated a relationship between TBMC and ANGII in response to stress (stress: r=-.229, p<0.05; post-stress: r=-.277, p<0.01) and between aldosterone and TBMC (stress: r=-.199, p<0.05) and TBMD (stress: r=-.250, p<0.01). Renin was not significantly correlated with TBMD nor TBMC in any population. Conclusion/Interpretations: These data suggest that stress-induced RAAS activation may be associated with lower TBMD and TBMC in girls. Despite small correlations, consistency across multiple measures of RAAS activation being apparent in adolescents is significant. This observation may indicate that stress activation of RAAS contributes to bone remodeling in early life.