Changes in bone mineral density with age, menopausal status and body mass index in Turkish women

Thyroid Hormones Are Not Associated with Plasma Osteocalcin Levels in Adult Population with Normal Thyroid Function

Thyroid hormones (THs) play an indispensable role in skeletal development and bone remodeling. Some studies have reported associations of THs with serum osteocalcin (OC) levels, but the results are quite inconsistent and the molecular mechanism of their simultaneous or interdependent activity on bone is almost unknown. Therefore, the aim of this study was to determine the possible associations of plasma THs with plasma OC levels and the possible mediating effect of OC on the relationship between THs and bone mineral density (BMD). For this purpose, out of the initial 1981 participants, we selected healthy euthyroid participants controlled for available confounding factors that can affect thyroid function and bone metabolism (N = 694). Given our results, we could not confirm any associations of THs with plasma OC levels nor the mediating effect of OC on the relationship between THs and BMD in euthyroid population. In the group of women controlled for menopause status (N = 396), we found a significant negative association of body mass index (BMI) with OC levels (β = −0.14, p = 0.03). We also found a negative association of free triiodothyronine (fT3) (β = −0.01, p = 0.02) and age (β = −0.003, p < 0.001) with BMD, and a positive association of BMI (β = 0.004, p < 0.001) and male gender (β = 0.1, p < 0.001) with BMD. In addition, we found significantly higher plasma OC levels and lower values of BMD in postmenopausal euthyroid women compared with premenopausal euthyroid women. In our opinion, the results of previous studies suggesting an association between circulating THs and serum OC levels may be influenced by an inconsistent selection of participants and the influence of confounding factors.

A review of menopause nomenclature

Menopause nomenclature varies in the scholarly literature making synthesis and interpretation of research findings difficult. Therefore, the present study aimed to review and discuss critical developments in menopause nomenclature; determine the level of heterogeneity amongst menopause definitions and compare them with the Stages of Reproductive Aging Workshop criteria. Definitions/criteria used to characterise premenopausal and postmenopausal status were extracted from 210 studies and 128 of these studies were included in the final analyses. The main findings were that 39.84% of included studies were consistent with STRAW classification of premenopause, whereas 70.31% were consistent with STRAW classification of postmenopause. Surprisingly, major inconsistencies relating to premenopause definition were due to a total lack of reporting of any definitions/criteria for premenopause (39.84% of studies). In contrast, only 20.31% did not report definitions/criteria for postmenopause. The present findings indicate that there is a significant amount of heterogeneity associated with the definition of premenopause, compared with postmenopause. We propose three key suggestions/recommendations, which can be distilled from these findings. Firstly, premenopause should be transparently operationalised and reported. Secondly, as a minimum requirement, regular menstruation should be defined as the number of menstrual cycles in a period of at least 3 months. Finally, the utility of introducing normative age-ranges as supplementary criterion for defining stages of reproductive ageing should be considered. The use of consistent terminology in research will enhance our capacity to compare results from different studies and more effectively investigate issues related to women's health and ageing.

Changes in bone mass associated with obesity and weight loss in humans: Applicability of animal models

The implications of obesity and weight loss for human bone health are not well understood. Although the bone changes associated with weight loss are similar in humans and rodents, that is not the case for obesity. In humans, obesity is generally associated with increased bone mass, an outcome which is exacerbated by advanced age and menopause. In rodents, by contrast, bone mass decreases in proportion to severity and duration of obesity, and is influenced by sex, age and mechanical load. Despite these discrepancies, rodents are frequently used to model the situation in humans. In this review, we summarise the existing knowledge of the effects of obesity and weight loss on bone mass in humans and rodents, focusing on the translatability of findings from animal models. We then describe how animal models should be used to broaden the understanding of the relationship between obesity, weight loss, and skeletal health in humans. Specifically, we highlight the aspects of study design that should be considered to optimise translatability of the rodent models of obesity and weight loss. Notably, the sex, age, and nutritional status of the animals should ideally match those of interest in humans. With these caveats in mind, and depending on the research question asked, our review underscores that animal models can provide valuable information for obesity and weight-management research.

Association of bone mineral density with the development of knee osteoarthritis in men and women: a cross-sectional study using the fourth and fifth Korea National Health and Nutrition Examination Surveys

Bone mineral density (BMD) and osteoarthritis (OA) were correlated but the relationship was varied according to sex. An association between lumbar spine and femur neck BMDs and OA showed a positive relation in women, while lumbar spine and pelvis BMDs in men were associated with OA with a negative relation.

PURPOSE

The purpose of this study was to evaluate the association of BMD in various body parts in conjunction with the presence or severity of radiographic knee osteoarthritis (KOA) in relation to sex.

METHODS

This study was a cross-sectional analysis using Korea National Health and Nutrition Examination Surveys. KOA was graded using the Kellgren-Lawrence (KL) grading system. Radiographic KOA was defined as a KL grade 2 or higher. The associations between KOA and BMD in certain body parts (femur, pelvis, lumbar, lower leg, and whole-body) were assessed. BMD was measured using dual-energy X-ray absorptiometry. The BMD of each body part was divided into quartiles and the relationship between KOA and BMD was examined according to sex.

RESULTS

BMD did not show a significant tendency according to KL grade in either sex. In men, the severity of KL grade have a statistically significant relationship with total femur (R² = 0.303, p < 0.05), femur neck (R² = 0.257, p < 0.05), lumbar (R² = 0.137, p < 0.05), and pelvis BMD (R² = 0.185, p < 0.05). In women, total femur (R² = 0.466, p < 0.05), lumbar (R² = 0.316, p < 0.05), pelvis (R² = 0.343, p < 0.05), and lower leg BMD (R² = 0.133, p < 0.05) were associated with the severity of KL grade. When the BMD was divided into quartiles, lumbar (p < 0.05) and pelvis BMD (p < 0.05) in men had statistically significant association with knee OA as BMD decreased. In women, femur neck (p < 0.05) and lumbar BMD (p < 0.05) were significantly associated with knee OA as BMD increased.

CONCLUSION

The relationship between BMD and OA severity varied according to sex. In women, there was a positive association between femur neck and lumbar BMD and OA, while BMD of the lumbar and pelvis in men was negatively correlated with OA.

LEVEL OF EVIDENCE

Cohort study, III.

Fat mass changes during menopause: a metaanalysis

OBJECTIVE

Data: Fat mass has been shown to increase in aging women; however, the extent to which menopausal status mediates these changes remains unclear. The purpose of this review was to determine (1) how fat mass differs in quantity and distribution between premenopausal and postmenopausal women, (2) whether and how age and/or menopausal status moderates any observed differences, and (3) which type of fat mass measure is best suited to the detection of differences in fat mass between groups.

STUDY

This review with metaanalyses is reported according to Metaanalysis of Observational Studies in Epidemiology guidelines.

STUDY APPRAISAL AND SYNTHESIS METHODS

Studies (published up to May 2018) were identified via PubMed to provide fat mass measures in premenopausal and postmenopausal women. We included 201 cross-sectional studies in the metaanalysis, which provided a combined sample size of 1,049,919 individuals and consisted of 478,734 premenopausal women and 571,185 postmenopausal women. Eleven longitudinal studies were included in the metaanalyses, which provided a combined sample size of 2472 women who were premenopausal at baseline and postmenopausal at follow up.

RESULTS

The main findings of this review were that fat mass significantly increased between premenopausal and postmenopausal women across most measures, which included body mass index (1.14 kg/m²; 95% confidence interval, 0.95-1.32 kg/m²), bodyweight (1 kg; 95% confidence interval, 0.44-1.57 kg), body fat percentage (2.88%; 95% confidence interval, 2.13-3.63%), waist circumference (4.63 cm; 95% confidence interval, 3.90-5.35 cm), hip circumference (2.01 cm; 95% confidence interval, 1.36-2.65 cm), waist-hip ratio (0.04; 95% confidence interval, 0.03-0.05), visceral fat (26.90 cm²; 95% confidence interval, 13.12-40.68), and trunk fat percentage (5.49%; 95% confidence interval, 3.91-7.06 cm²). The exception was total leg fat percentage, which significantly decreased (-3.19%; 95% confidence interval, -5.98 to -0.41%). No interactive effects were observed between menopausal status and age across all fat mass measures.

CONCLUSION

The change in fat mass quantity between premenopausal and postmenopausal women was attributable predominantly to increasing age; menopause had no significant additional influence. However, the decrease in total leg fat percentage and increase in measures of central fat are indicative of a possible change in fat mass distribution after menopause. These changes are likely to, at least in part, be due to hormonal shifts that occur during midlife when women have a higher androgen (ie, testosterone) to estradiol ratio after menopause, which has been linked to enhanced central adiposity deposition. Evidently, these findings suggest attention should be paid to the accumulation of central fat after menopause, whereas increases in total fat mass should be monitored consistently across the lifespan.

Effect of surgical and natural menopause on proximal femur morphometry in obese women

The purpose of this study is to determine whether there are differences in proximal femur parameters of women subjected to menopause surgically or naturally. In this study, 10 parameters belonging to proximal femur of a total of 60 women cases of whom 30 had a mean age of 55.53 ± 4.57 years; body mass index, 33.06 ± 4.21 kg/m²; menopause age, 48.10 ± 5.92; and menopause years, 7.50 ± 4.58; and who were subjected to natural menopause; and 30 women whose mean age was 56.10 ± 6.87 years; body mass index, 33.33 ± 3.76 kg/m²; menopause age, 48.00 ± 4.64 years and menopause year, 8.10 ± 7.29; who were subjected to surgical menopause, and who did not use hormone replacement, were examined by radiography. Their anthropometric measurements, body compositions, blood hormone analyses (FSH, LH, estradiol, progesterone) and bone mineral densities (femur neck, femur total, lumbar t-score) were evaluated. It was found that there was no difference between surgical and natural menopause with respect to proximal femur parameters (p > 0.05). It was also found that FSH levels were high in the surgical menopause group and there were significant differences between the groups (p < 0.040). No significant difference was found even though bone mineral density t-score tests were lower in the surgical menopause group (p > 0.05). It was found that the difference in low bone mineral density level and high FSH values in the surgical menopause group do not have a relationship with proximal femur morphometry. It was determined that even though the women did not have ovaries, there was no difference between surgical menopause women and natural menopause women with respect to proximal femur morphometry.

Decreasing trend of bone mineral density in US multiethnic population: analysis of continuous NHANES 2005-2014

Studies examining recent bone mineral density (BMD) trends in the US population are limited. In our study, we found that age-adjusted mean BMD among US men and women was stable from 2005 to 2010, but then declined in 2013-2014. We also explored factors associated with decreasing BMD in recent years.

INTRODUCTION

Osteoporosis prevalence in the USA declined between 1988 and 2006, while the declining trend in hip fracture may have plateaued in 2013-2014. We aimed to examine whether there has been a corresponding change in BMD trajectory for the US population.

METHODS

Continuous National Health and Nutrition Examination Survey (NHANES) data from 2005-2006 to 2013-2014 were analyzed to examine BMD trends among US men and women aged 30 years and older and among different race/ethnicity subgroups. ANOVA and Bonferroni adjustments were used to examine the differences in mean BMD, and multiple linear regressions adjusting for potential confounding effects were employed to examine BMD trends.

RESULTS

After age standardization, the mean BMD of the femur neck for the first three NHANES cycles was stable (all p > 0.1) in both men and women, but significantly decreased in 2013-2014, from 0.864 g/cm2 to 0.846 g/cm2 (p = 0.0025) in men and from 0.789 to 0.771 g/cm2 (p = 0.03) in women. The overall mean femur neck BMD in 2013-2014 was significantly lower than that in earlier survey cycles in both men and women, even after adjusting for multiple covariates, including age, race, physical activity, previous fracture, BMI, and other variables. Similar results were observed in subgroup analyses of race and sensitivity analyses.

CONCLUSIONS

Age-adjusted mean BMD decreased in 2013-2014 in both men and women, and this significant decrease was also observed in sensitivity and subgroup analyses. The decreased BMD in 2013-2014 still remained significant even after being adjusted for multiple potentially confounding effects.

Variation of canine vertebral bone architecture in computed tomography

Focal vertebral bone density changes were assessed in vertebral computed tomography (CT) images obtained from clinically healthy dogs without diseases that affect bone density. The number, location, and density of lesions were determined. A total of 429 vertebral CT images from 20 dogs were reviewed, and 99 focal vertebral changes were identified in 14 dogs. Focal vertebral bone density changes were mainly found in thoracic vertebrae (29.6%) as hyperattenuating (86.9%) lesions. All focal vertebral changes were observed at the vertebral body, except for a single hyperattenuating change in one thoracic transverse process. Among the hyperattenuating changes, multifocal changes (53.5%) were more common than single changes (46.5%). Most of the hypoattenuating changes were single (92.3%). Eight dogs, 40% of the 20 dogs in the study and 61.6% of the 13 dogs showing focal vertebral changes in the thoracic vertebra, had hyperattenuating changes at the 7th or 8th thoracic vertebra. Our results indicate that focal changes in vertebral bone density are commonly identified on vertebral CT images in healthy dogs, and these changes should be taken into consideration on interpretation of CT images.

A new method for the estimation of age at death by using electrical impedance: A preliminary study

Estimation of age at death is an important part of physical and forensic anthropology. The aim of this study was to investigate whether bioelectrical impedance analysis (BIA) of long bones can be used in the field of forensic medicine as a method to estimate age at death. BIA is easy to use and allows repeat measurements to be taken over time, and the equipment is inexpensive and portable. Impedance values (Z values) in 378 long bones (humeri, radii, femora, tibiae) of 40 male (233 bones) and 26 female (145 bones) autopsy cadavers were measured using two wire electrodes (connected to an alternating current device and a measuring device) inserted into the metaphyses of long bones. Computed tomography of the greater trochanter of the femur was also analyzed to evaluate bone mineral density (BMD). The results showed that Z values could be used to estimate age in males, and with an age cut-off point of 50 years in females. When estimating age at death from femur and tibia in males by using BIA, it is not necessary to consider the length of subjects. And it was thought that Z values reflected BMD. Among the long bones, the tibia is the most suitable and easy to use for Z value measurement. Z value measurement is a useful method for quantitative evaluation of age at death that can be performed quickly with inexpensive, portable equipment.

Age-related bone mineral density patterns in Koreans (KNHANES IV)

CONTEXT

Bone loss is considered to begin with menopause in women and later in life in men; however, several recent studies have reported that bone loss began in young adults. There are still discordant results concerning age-related changes in bone mineral density (BMD), especially in nonvertebral bone.

OBJECTIVE

The objective of the study was to investigate the age-related changes in BMD in Korean youth.

DESIGN AND SETTING

This was a population-based, cross-sectional study from the Fourth Korea National Health and Nutrition Examination Surveys.

PARTICIPANTS

A total 10,575 Korean (4,731 males and 5,844 females) aged 10-80 yr were included.

MAIN OUTCOME MEASURES

BMD at the spine and hip was measured using dual X-ray absorptiometry.

RESULTS

Age-related bone loss at the femoral neck in males occurred continuously with temporary acceleration phase after achieving peak bone mass (PBM). In contrast, age-related bone loss at total hip in both sexes and femoral neck in females showed three obvious phases: acceleration, consolidation, and then the second acceleration phase after reaching PBM. Interestingly, this pattern of bone loss was more significant in the total hip and thus showed the acceleration phase until the late 20s and the consolidation phase until the late 40s. Early accelerated loss of BMD was not observed at the lumbar spine in each sex. Although body mass index and body fat percentage were more related with BMD than other clinical parameters, they could not explain the early accelerated loss of BMD at the femur.

CONCLUSIONS

There was an accelerated bone loss at the femur in both sexes during early adulthood and more than 60% of the bone loss before age 50 yr occurred during this period.

Different involutionary changes in bone mineral density with age in three skeletal sites in healthy Polish women

The aim of the study was to estimate the differences in bone mineral density (BMD) at three skeletal sites, with regard to age and menopausal status. The study was conducted between 2001 and 2006 in the Polish city of Wrocław and the sample was comprised of 440 healthy female inhabitants aged 40-88years. The measurements of bone mineral density were taken at three sites: femoral neck, Ward's triangle and trochanter major. Two bone mineral density characteristics were used in further analysis: absolute measure of bone mineral density (BMD) expressed in g/(100mm)(2), and % of BMD of the peak value calculated for young adults (20-45, USA reference population). Pre- and postmenopausal status was defined according to occurrence of menstruation within the last 60days. The changes in bone mineral density with age showed significantly different patterns in different skeletal sites. While the decrease in bone mineral density in the femoral neck and Ward's triangle were parallel and gradual, the changes in trochanter major were very small and between the age groups 51-55 and 71-75, nearly unnoticeable. A comparison between pre- and postmenopausal women aged 46-55, showed a significant effect of menopausal status. The average bone mineral densities in the three skeletal sites were higher in premenopausal than in postmenopausal women. The highest value of bone mineral density was found in the femoral neck, significantly lower in Ward's triangle, and a little lower (non-significantly) in the trochanter major than in the Ward's triangle. Postmenopausal women had a little higher BMD value in the trochanter major than in the Ward's triangle site.

Multiple vibration intensities and frequencies for bone mineral density improvement

Devices that deliver controlled quantum vibration intensities at multiple frequencies (QVIMF) provide optimal stress to the musculoskeletal system for improved bone mineral density and muscle strength. This paper presents development of a QVIMF system and pilot study to determine device performance. Development is centered on specially-designed actuators that comprise multiple nodes of controlled and smooth, but variable rates of contact on a telescoping platform through sets of damping subsystems. The combination of specially-designed actuators and damping subsystems, powered by a DC controlled motor, delivers quantum busts of vibration at multiple frequencies resulting in whole body vibration. An initial feasibility study involved a 79 year old adult male. After IRB approval from both the University of Wisconsin-Milwaukee (UWM) and the Zablocki VA Medical Center, Milwaukee, the subject's bone mineral density (BMD) was measured by dual x-ray absorptimetry (DXA) at baseline. The subject then visited the UWM laboratory for two fifteen-minute vibration sessions per visit, three times a week for a total of 60 visits. Post-vibration BMD was again measured by DXA. Comparison pre- and post-vibration test results showed increases in BMD at the femoral neck, trochanter, total hip, forearm and lower lumbar spine (L1-4).

Age-related trends in phalangeal bone mineral density in Sri Lankan men and women aged 20 years or more

To establish normative reference values and to study the age-related trends in phalangeal bone mineral density (BMD), 4504 male and 5215 female volunteers aged 20 yr or more were recruited from 7 provinces from October 2004 to October 2005. Subjects suffering from diseases and those who were taking medications, which could affect BMD were excluded from the analysis (n=530). Phalangeal BMD was measured in the nondominant hand using an AccuDXA. Men and women were categorized to age groups of 20-29 (1087 men and 1079 women), 30-39 (1122 men and 1146 women), 40-49 (1148 men and 1455 women), 50-59 (810 men and 1111 women), 60-69 (250 men and 335 women), and 70 yr or more (87 men and 94 women). Mean BMDs (SD) of men in above categories were 0.595 (0.057), 0.603 (0.061), 0.591 (0.066), 0.576 (0.069), 0.558 (0.077), and 0.522 (0.079) g/cm2, respectively. The corresponding BMDs (SD) in women were 0.495 (0.057), 0.506 (0.062), 0.502 (0.064), 0.462 (0.072), 0.406 (0.072), and 0.340 (0.055) g/cm2, respectively. Peak BMD was seen in 30-39-age category in both sexes. Women after 50 yr lost BMD at a rate of 0.006 (standard error 0.0003) g/cm2/yr, whereas the corresponding value in men was 0.002 (standard error 0.0001) g/cm2/yr. These data provide normative reference data for the calculation of T-score and Z-score for phalangeal BMD in Sri Lankan men and women aged more than 20 yr.

Linkage and association of the CA repeat polymorphism of the IL6 gene, obesity-related phenotypes, and bone mineral density (BMD) in two independent Caucasian populations

Genetic factors play an important role in osteoporosis and obesity, two serious public health problems in the world. We investigated the relationships between obesity-related phenotypes, bone mineral density (BMD) and the CA repeat polymorphism of the IL6 gene in two large independent samples using the quantitative transmission disequilibrium test (QTDT). The first sample consisted of 1,816 individuals from 79 multigenerational pedigrees. Each pedigree was identified through a proband with BMD Z-scores </=-1.28 at the hip or spine. The second sample was a randomly ascertained set of 636 individuals from 157 nuclear families. Ten alleles containing 9-18 CA repeats were identified in our Caucasian populations. For body mass index (BMI), fat mass and percentage fat mass (PFM), highly significant (P<0.01) or significant (P<0.05) results were found for linkage in our sample of nuclear families and for association in the multigenerational pedigrees. We also observed weak evidence for linkage (P=0.069) with spine BMD and for association with hip BMD in the sample of multigenerational pedigrees. Our results suggest that genetic variation in or near the IL6 locus may be involved in the etiology of obesity and osteoporosis.