Clinical and body composition predictors of bone turnover and mineral content in obese postmenopausal women

Role of Body Fat and Metabolic Rate in Site-Specific Fracture Risk: A 20-Year Taiwanese Cohort Study

BACKGROUND Osteoporotic fractures are a significant public health problem, yet traditional risk assessment methods have limitations. This retrospective study used the integrated Healthcare information (iHi) Data Platform of China Medical University Hospital (CMUH) (2000-2020) to evaluate associations between body mass index (BMI), bone mineral density (BMD), body fat percentage (BFP), basal metabolic rate (BMR), and site-specific fracture risk in 9583 Taiwanese individuals. MATERIAL AND METHODS We extracted DXA-measured BMD, BMI, BFP, and BMR data from CMUH's iHi Platform. Fracture events were identified using ICD-9/10 codes and verified through radiology reports. Cox proportional hazards regression models estimated fracture risk, adjusting for demographic and clinical factors. Mediation analysis quantified the contributions of BFP and BMR to the BMI-fracture relationship. RESULTS During median follow-up of 8.7 years, 1672 fractures (17.4%) occurred. Individuals with normal BMD showed an 82% lower fracture risk compared to those with osteoporosis (adjusted hazard ratio [aHR]=0.18, 95% CI: 0.15-0.22, p<0.001). Normal BFP significantly reduced fracture risk by 77% versus low BFP (aHR=0.23, 95% CI: 0.07-0.72, p=0.012). Higher BMR was consistently protective, with aHR=0.54 (95% CI: 0.36-0.82, p=0.004) for BMR ≥1500 versus BMR<1000. While underweight increased fracture risk (aHR=1.75, 95% CI: 1.29-2.36, p<0.001), obesity conferred no significant protection (aHR=1.04, 95% CI: 0.89-1.21, p=0.58). CONCLUSIONS This study demonstrates that fracture risk assessment should incorporate BFP and BMR alongside BMD and BMI. The "BMI paradox" was explained through mediation analysis, revealing BFP and BMR as critical intermediaries accounting for 50% and 32% of the BMI-fracture relationship, respectively. These findings support developing ethnicity-specific fracture risk models integrating body composition metrics for more precise risk stratification.

Relationships between multivitamins, blood biochemistry markers, and BMC and BMD based on RF: A cross-sectional and population-based study of NHANES, 2017-2018

BACKGROUND

Previous studies have separately suggested a possible association between the vitamin exposure, blood biochemical indicators, and bone density. Our study aimed to investigate the relationship between vitamin exposure serum concentrations, blood biochemical indicator serum concentrations, and BMC and BMD using the NHANES 2017-2018 nutrient survey data. This population-based cross-sectional study aimed to explore these associations.

METHODS

In this study, we measured vitamin serum concentrations, serum ion serum concentrations, and serum biochemical indicators in adults participating in the NHANES. Skeletal status was assessed by evaluating BMC and BMD in the whole body. Given the inclusion of multiple variables and diverse data types, we used the RF to fit a multivariable model to estimate the associations between vitamin serum concentrations, blood biochemical indicator serum concentrations, and skeletal status.

RESULTS

Under the dimension reduction and comparison selection of RF model, we identified ALP, CPK, and creatinine serum concentrations as the most important factors associated with BMC and BMD in multiple skeletal sites, and the gender, age, height, weight, and body mass index which were found to be related to BMC and BMD in different skeletal sites. Vitamin D and blood calcium serum concentrations were not the important factors associated with BMC and BMD and the three blood biochemical indexes were more important than the vitamin level for BMC and BMD.

CONCLUSION

The effect of vitamin serum concentrations and blood calcium serum concentrations on human bone density was not significant. ALP, CPK and creatinine serum concentrations body development indicators were identified as the most important factors related to bone status. The RF model can be used to comprehensively evaluate the effects of vitamin content and blood biochemistry serum concentrations in adults on BMC and BMD.

Correlation between Body Composition and Bone Mineral Density Differs by Sex and Skeletal Site in Overweight and Obese Chinese Subjects

Previous studies have yielded inconsistent results regarding the relationship between obesity and bone mineral density (BMD). The aim of this study was to determine the influence of body composition on BMD and the serum sclerostin level in overweight and obese adults. The study had a cross-sectional design and included 90 men and 118 women with a body mass index ≥25. Fat mass, lean mass, and spinal and pelvic BMD were measured using dual-emission X-ray absorptiometry. Subcutaneous fat, visceral fat, and lean mass were measured between L2 and L3 by 16-slice spiral computed tomography. The serum sclerostin level was determined by enzyme-linked immunosorbent assay. Pearson analysis showed that fat mass and appendicular lean mass were positively correlated with spinal BMD in both sexes. A positive association of both fat mass and lean mass with pelvic BMD, which was stronger in women, was also found. Partial correlation analysis showed the positive association between fat mass and BMD was significantly attenuated but the positive association between lean mass and pelvic BMD remained after adjustment for age and body weight. A negative correlation was observed between visceral fat and spinal and pelvic BMD only in women, and the positive association between lean mass with pelvic BMD was more obvious in women than in men, indicating body composition seemed to have a greater impact on the BMD in women. The serum sclerostin level was positively associated with BMD but not with body composition. These findings suggest that the correlation between body composition and BMD is influenced by sex and skeletal site.

Serum Resistin Levels and Related Genetic Variants Are Associated With Bone Mineral Density in Postmenopausal Women

BACKGROUND

Osteoporosis is a multifactorial disorder and a number of genetic variants or loci responsible for bone mineral density (BMD) have been identified. Resistin, a novel adipokine has diverse role in human body including its function in bone remodeling. The objective of this study was to see the association of serum resistin levels and related genetic variants (rs3931020, rs13144478) with BMD in postmenopausal females.

METHODS

This comparative analytical study was conducted on postmenopausal osteoporotic (n=101), osteopenic (n=77) and non-osteoporotic (n=74) females. For comparison and correlational analysis, Kruskal-Wallis test and Spearman's rho correlation were used respectively. Hardy-Weinberg equilibrium (HWE) was calculated by using Chi-square test (χ2).

RESULTS

There was significant difference in the serum levels of resistin (p <0.001), among the three groups. Significant negative correlation of resistin was observed with BMD at various sites. Serum resistin levels were significantly low in the rs3931020 AA homozygous genotype (p = 0.010), and significantly high in the rs13144478 AT heterozygous genotype (p = 0.020), BMD at all sites except left femoral neck was significantly high in rs3931020 AA genotype, while BMD at lumbar spine, left hip and total BMD were significantly low in the rs13144478 TT homozygotes.

CONCLUSION

High serum resistin levels are associated with low BMD and single nucleotide variation in rs3931020 and rs13144478 may lead to high serum resistin levels and low bone mineral density. Resistin can serve as a new genetic marker, potential therapeutic target and predictor of osteoporosis.

The Inverse Association of Leg Fat Mass and Osteoporosis in Individuals with Type 2 Diabetes Independent of Lean Mass

PURPOSE

Recent studies revealed that high levels of thigh fat were independently associated with better glucose and lipid metabolism, as well as lower risk of hypertension and cardiometabolic disease. Therefore, the purpose of this study was to evaluate the association between leg fat mass (FM) and osteoporosis (OP) in individuals with type 2 diabetes (T2DM).

PATIENTS AND METHODS

In this cross-sectional study, a total of 1,259 individuals aged 50 years or older with T2DM (female 536, male 723) were included. A bioelectrical impedance analyser was used to assess the segment body composition containing FM and lean mass (LM) of arms, legs, and trunk. Bone mineral density (BMD) was determined by dual-energy X-ray absorptiometry.

RESULTS

Leg FM was positively correlated with BMD of all sites in females and BMD of femoral neck and total hip in males after adjusting age, diabetes duration, glucose and lipid metabolism indexes, and lifestyle (all P<0.05). LM was positively associated with BMD at almost sites (P<0.001), while leg FM/LM ratio had no relationship with BMD at any skeleton sites (P>0.05). Compared with the bottom tertile group of leg FM, the risk of OP was significantly lower in the top tertile group both in females (T3 vs T1: OR=0.206, 95% CI=0.098-0.433, P<0.001) and males (T3 vs T1: OR=0.385, 95% CI=0.182-0.815, P<0.05), even after adjusting for LM.

CONCLUSION

In the present study, higher leg FM was correlated with the lower risk of OP in both men and postmenopausal women with T2DM independently of total LM.

Serum resistin levels as predictor of low bone mineral density in postmenopausal women

Resistin, a novel adipokine may play an important role in bone metabolism. The study is designed to discover the association of bone mineral density (BMD) with serum resistin levels, anthropometric measures and to elucidate serum resistin as a predictor of BMD in postmenopausal women. Postmenopausal women (n = 160) were recruited and divided into two groups, non-osteoporotic (n = 70) and osteoporotic (n = 90). BMD was evaluated by DXA scan. High serum resistin levels and low weight are independent contributors to low BMD and can influence BMD at lumbar spine, right femoral neck, right hip, left femoral neck, and left hip in postmenopausal women.