Association between anthropometric measures and spinal bone mineral density

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.

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.

IN WHICH PATIENTS IS IT POSSIBLE TO PERFORM STANDALONE LATERAL LUMBAR INTERBODY FUSION WITHOUT CAGE SUBSIDENCE?

ABSTRACT Objective: To identify the factors related to the non-occurrence of cage subsidence in standalone lateral lumbar interbody fusion procedures. Methods: Case-control study of single level standalone lateral lumbar interbody fusion (LLIF) including 86 cases. Patients without cage subsidence composed the control group (C), while those in the subsidence group (S) developed cage subsidence. Preoperative data were examined to create a risk score based on correlation factors with S group. The proven risk factors were part of an evaluation score. Results: Of the 86 cases included, 72 were in group C and 14 in group S. The following risk factors were more prevalent in group S compared to C group: spondylolisthesis (93% vs 18%; p<0.001); scoliosis (31% vs 12%; p=0.033); women (79% vs 38%; p=0.007); older patients (average 57.0 vs 68.4 years; p=0.001). These risk factors were used in a score (0-4) to evaluate the risk in each case. The patients with higher risk scores had greater subsidence (p<0.001). Scores ≥2 were predictive of subsidence with 92% sensitivity and 72% specificity. Conclusions: It was possible to correlate the degree of subsidence in standalone LLIF procedures using demographic (age and gender) and pathological (spondylolisthesis and scoliosis) data. With a score based on risk factors and considering any score <2, the probability of non-occurrence of subsidence following standalone LLIF (negative predictive value) was 98%.

Fam3c modulates osteogenic cell differentiation and affects bone volume and cortical bone mineral density

Fam3c, a cytokine-like growth factor, has been suggested to have a role in epithelial-to-mesenchymal transition (EMT), tumor growth and metastasis. A single-nucleotide polymorphism affecting bone mineral density has been found in the first intron of the Fam3c gene in a study analyzing an Asian population cohort. Other independent studies on different population cohorts have found the fam3c locus to be associated with bone mineral density and fractures. In order to investigate the role of Fam3c in bone biology, we have generated a Fam3c knock-out (KO) mouse strain. The Fam3c KO mice were found to have normal appearance, behavior and fertility, but small changes in bone morphology and content were also observed. Micro-CT analysis of tibiae of the female mice revealed decreased number of trabeculae. In male mice the changes in the bone phenotype were smaller, but hematological changes were observed. Furthermore, there was a negative correlation between body weight and tibial trabecular and cortical bone volume in the male KO mice. There was a small increase in cortical bone mineral density, but in the lateral direction of tibiae the breaking strength was reduced. Fam3c KO bone marrow cells showed accelerated osteogenic differentiation and mineralization in vitro. The reduced number of bone trabeculae in Fam3c KO mice and the stimulated osteogenic differentiation indicate a role for Fam3c in osteoblast differentiation and bone homeostasis.

Recent progress in bone imaging for osteoporosis research

Advances in bone imaging techniques have provided tools for analyzing bone structure at the macro-, micro- and nano-level. Quantitative assessment of macrostructure can be achieved using dual X-ray absorptiometry (DXA) and quantitative computed tomography (QCT), particularly volumetric quantitative CT (vQCT). In vivo quantitative techniques for assessing the microstructure of trabecular bone non-invasively and non-destructively include high-resolution CT (HR-CT) and high-resolution magnetic resonance (HR-MR). Compared with MR imaging, CT-based techniques have the advantage of directly visualizing the bone in the axial skeleton, with high spatial resolution, but the disadvantage of delivering a considerable radiation dose. Micro-CT (μCT), which provides a higher resolution of the microstructure and is principally applicable in vitro, has undergone technological advances such that it is now able to elucidate the physiological skeletal change mechanisms associated with aging and determine the effects of therapeutic intervention on the bone microstructure. In particular, synchrotron μCT (SR-CT) provides a more detailed view of trabecular structure at the nano-level. For the assessment of hip geometry, DXA-based hip structure analysis (HSA) and CT-based HSA have been developed. DXA-based HSA is a convenient tool for analyzing biomechanical properties and for assuming cross-sectional hip geometry based on two-dimensional (2D) data, whereas CT-based HSA provides these parameters three-dimensionally in robust relationship with biomechanical properties, at the cost of greater radiation exposure and the lengthy time required for the analytical procedure. Further progress in bone imaging technology is promising to bring new aspects of bone structure in relation to bone strength to light, and to establish a means for analyzing bone structural properties in the everyday clinical setting.

Osteoporosis Risk Factors and Association with Somatotypes in Males

BACKGROUND

Osteoporosis is a systemic and metabolic skeletal disease characterized by reduced bone mass, changes in microarchitecture, and consequential increased fracture risk. Previous reports described a relationship between bone content with fat mass and lean body mass. In this study, we assessed osteoporosis risk factors and the association with somatotypes in males aged 45-65 years.

METHODS

Standard axial spine and proximal femur bone mineral density (BMD) were measured using dual x-ray (DXA) absorptiometry in 70 healthy men. Heath-Carter procedure was followed to assess individual's somatotype.

RESULTS

All body types were grouped as endomorphy, mesomorphy, and ectomorphy. Moderate to weak correlations were found between lumbar BMD with endomorphy and mesomorphy. Negative correlation was found between lumbar BMD and ectomorphy. Total femur BMD correlated positively with endomorphy and mesomorphy and negatively correlated with ectomorphy. Body mass index correlated weakly with lumbar, femur neck, and total femur BMD. Multiple regression analysis revealed that endomorphy was significantly related to BMD measurements at lumbar spine (standardized coefficient, SC = 0.51, p = 0.001), femur neck (SC = 0.52, p = 0.001), and total femur BMD (SC = 0.41, p = 0.01). Lumbar BMD and age, hand grip strength, smoking, tea and coffee consumption, calorie expenditure, calcium intake, PTH, albumin, total protein, sex hormone-binding globulin, and testosterone were not significantly correlated.

CONCLUSIONS

Endomorphy seems related to high BMD values at the lumbar spine and the proximal femur in middle-aged men. Somatotype together with daily calorie expenditure may be taken into account when assessing risk factors for male osteoporosis.

Association between bone mineral density (DXA), body structure, and body composition in middle-aged men

The association between bone mass, body structure, and body composition was explored in 156 men, 40 years of AGE. Bone mineral density (total body, lumbar spine, left arm, and left leg) was obtained by dual-energy X-ray absorptiometry (DXA; Hologic QDR 4500A). Body structure was determined from a battery of anthropometric dimensions with a principal components analysis. Body composition was estimated with DXA. From the 24 anthropometric dimensions, three components were extracted and identified as muscle, fat, and skeletal length. Significant correlations between the muscle component and all BMD measurements (r = 0.28-0.44) were obtained. Except for BMD of the left arm, which correlated significantly, but negatively, with the fat component (r = -0.16), no significant relations were found between the fat component and BMD. There were significant correlations between lean mass, fat mass, and BMD measurements. The correlations were higher between lean mass and BMD (r = 0.22-0.44) than between fat mass and BMD (r = 0.08-0.24). The multiple regression analysis revealed that except for BMD of the left arm only lean mass or the muscle component, and not fat mass or the fat component, were independent predictors of BMD. It is concluded that the principal anthropometric determinant of BMD in middle-aged men is lean mass or muscle.

Mandibular condyle bone mineral density measurement by quantitative computed tomography: a gender-related difference in correlation to spinal bone mineral density

We conducted volunteer studies to assess age-related changes of mandibular condyle bone mineral density (BMD) and its correlation to the spinal BMD. Quantitative computed tomography was performed on the condyles and spines (L1-3) of 210 healthy subjects (114 men and 96 women, aged 5-85 years). A separate study was performed on 73 young student subjects (39 men and 34 women, aged 23-25 years). The mandibular condyle BMD showed a decrement rate similar to spinal BMD in men, but in women the decrement rate of the mandibular condyle BMD was lower than that of the L1-3 BMD. On the other hand, correlation coefficients in BMD between the mandibular condyle and spine were similar in women and men. Gender-related differences were found to be dramatic when assessed in the young student group; the mandibular condyle and spinal BMDs were highly correlated in women (r = 0.82, p < 0.0001), but no correlation was found in men (r = 0.22). Taken together, these results suggest that the same regulatory mechanisms exist in the mandibular condyle and spine BMDs. However, aside from the spine BMD, additional undefined factor(s), including mechanical stress from the occlusion, may be involved in maintaining mandibular BMD.