The causal relationship between abdominal obesity and lower bone mineral density: A two-sample mendelian randomization study

Disentangling the divergent causal pathways underlying the association between body mass index and bone mineral density: a comprehensive Mendelian randomization study

BACKGROUND

While the protective role of body mass index (BMI) in bone mass has been well-documented, the divergent associations between BMI and estimated bone mineral density (eBMD), attributed to its highly heterogeneous nature, remain insufficiently understood.

METHODS

Leveraging the hitherto largest genome-wide summary statistics, we conducted a two-sample Mendelian randomization (MR) to re-evaluate the effect of genetically predicted BMI on eBMD. Then, MR-Clust was applied to examine the potential presence of distinct causal pathways underlying the BMI-eBMD link. Utilizing tissue-partitioned MR, we estimated the distinct effects of separated tissue-specific subcomponents of BMI on eBMD, further supplemented by multivariable MR of body composition phenotypes on eBMD.

RESULTS

We reconfirmed the significant positive association between genetically predicted BMI and eBMD (βIVW = 0.13, P value = 1.28 × 10-34). Potential distinct causal pathways contributing to the observed total effect were identified by MR-Clust, with some exerting a protective effect while others leading to its deterioration. Tissue-partitioned MR suggested a marginally independent protective association between skeletal muscle-tissue instrumented BMI and eBMD (βIVW = 0.14, P value = 4.98 × 10-2) after accounting for adipose-tissue instrumented BMI, which was supported by the independent association between genetically predicted lean mass and eBMD after accounting for other body composition phenotypes.

CONCLUSIONS

Our results shed preliminary insights into the intricate relationship between obesity and bone mass, highlighting divergent causal pathways underlying the association between BMI and eBMD. Our findings emphasize the potential importance of precision obesity management over merely a general indicator as BMI in future public health strategies for osteoporosis prevention.

Correlations Between TyG-Related Indices and Bone Health: A Cross-Sectional Study of Osteoporosis in a Rural Chinese Population

Background

Osteoporosis (OP) is a major metabolic bone disease with significant health and socioeconomic impacts. The triglyceride-glucose (TyG) index and its derivatives, which reflect insulin resistance (IR), may play a role in bone metabolism. However, the relationship between TyG indices and OP is unclear. This study aimed to explore the association between TyG indices and OP in a low-income rural Chinese population.

Methods

This cross-sectional study was conducted in rural Tianjin, China, in 2020. Participants aged 60 years or older were included. Data were collected through interviews, including sociodemographic and clinical information, and physical examinations. Bone mineral density (BMD) of the femoral neck was measured using dual-energy X-ray absorptiometry (DXA). Multivariate regression models and restricted cubic spline (RCS) curves were used to assess the relationships between TyG indices and OP.

Results

A total of 437 individuals were included in the final analysis, with 38 diagnosed with osteoporosis (prevalence of 8.7%). After adjusting for all covariates, each 1-unit increase in triglyceride-glucose-body mass index (TyG-BMI) was associated with a 2% lower risk of osteoporosis, (OR: 0.98, 95% CI: 0.96-1.00, P=0.029), especially in women, individuals with hypertension, and non-diabetic populations. The OP risk of the fourth quartile (Q4) of the triglyceride-glucose-waist circumference (TyG-WC) index after correcting for all covariates is 5.58 times that of the first quartile (Q1)(OR: 5.58, 95% CI: 1.14-27.41, P=0.034). Linear regression showed a positive correlation between TyG-BMI and BMD, particularly in women, individuals under 70, and those with hypertension or non-hypertension, with the strongest correlation in the non-hypertensive group.

Conclusion

TyG-related indices are associated with OP, suggesting a potential role in the early prevention and management of osteoporosis in this population, ultimately improving public health outcomes.

Association between a body shape index and bone mineral density in US adults based on NHANES data

The relationship between a body shape index (ABSI) and bone mineral density (BMD) remains uncertain, prompting further investigation. This study aims to elucidate the association between ABSI and BMD using data from the 2011-2018 National Health and Nutrition Examination Survey (NHANES), involving participants aged 20-60. ABSI was calculated using the formula: ABSI = 1000 × waist circumference (m)×weight (kg)-2/3×height (m)5/6. The analysis employed weighted multiple linear regression, smooth curve fitting, stratified analysis, and interaction tests to explore the relationship between ABSI and total BMD. The study included 10,291 participants, with a mean age of 39.11 ± 10.77 years, and 49.20% were women. The average ABSI was 80.21 ± 1.50. Total BMD, thoracic spine BMD, lumbar spine BMD, and pelvis BMD were measured, with mean values of 0.82 ± 0.11 g/cm², 1.03 ± 0.15 g/cm², and 1.24 ± 0.16 g/cm2, respectively. A negative correlation between ABSI and total BMD was observed. In the fully adjusted model, individuals in the highest ABSI quartile had total BMD levels 0.045 g/cm² lower than those in the lowest quartile. Interaction tests showed a consistent association between ABSI and total BMD across subgroups, with variations in sex and BMI. This analysis of NHANES data confirms a persistent negative association between ABSI and BMD, suggesting that ABSI could be useful in osteoporosis prevention and diagnosis.

Analysis of the predictive value of the Geriatric Nutritional Risk Index for osteoporosis in elderly patients with T2DM: a single-center retrospective study

BACKGROUND

Malnutrition is recognized as a risk factor for osteoporosis and T2DM. Previous studies have demonstrated the relationship between nutritional assessment tools and BMD. However, few studies have compared the effects of three nutritional risk assessment tools (GNRI, CONUT, and PNI). This study aimed to investigate the correlation between three nutritional assessment tools and BMD and to compare their validity in predicting osteoporosis in type 2 diabetes mellitus in the elderly.

METHODS

This retrospective study collected clinical data from 525 elderly patients with type 2 diabetes mellitus and categorized the patients into osteoporotic and non-osteoporotic groups. The correlation between the three nutritional assessment tools and BMD was analyzed using Spearman partial correlation. Binary logistics regression was used to analyze the relationship between GNRI and osteoporosis. ROC curves were used to compare the validity of GNRI, PNI, and CONUT in predicting osteoporosis.

RESULTS

Spearman's partial correlation showed a positive correlation between femoral neck BMD and lumbar spine BMD, but no correlation was observed between total hip BMD and GNRI. Logistic regression analyses showed no association between PNI, CONUT scores, and the development of osteoporosis. After adjusting for age, sex, smoking, alcohol consumption, BMI, ALB, Cr, UA, FBG, TG, and HDL, the correlation between GNRI and osteoporosis remained. ROC curve analysis showed that GNRI in combination with age and albumin had better predictive ability for osteoporosis than PNI and CONUT.

CONCLUSION

GNRI was an independent protective factor against osteoporosis in elderly patients with T2DM, and the predictive ability of GNRI for osteoporosis in elderly patients with T2DM was better than that of PNI and CONUT scores.

Associations of Dietary Anthocyanidins Intake with Bone Health in Children: A Cross-Sectional Study

PURPOSE

Bone health and body composition share several common mechanisms like oxidative stress and inflammation. Anthocyanins have antioxidant and anti-inflammatory properties. We have reported that anthocyanins are associated with better body composition in children, but the associations with bone health have not been elucidated. We aimed to explore the association of anthocyanins with bone mineral content (BMC) and bone mineral density (BMD) at multiple sites in children.

METHODS

In this cross-sectional study, 452 Chinese children aged 6-9 years were recruited. A validated 79-item food frequency questionnaire was used to collect dietary information. BMC and BMD at multiple sites (whole body; whole body excluding head, WBEH; limbs; arms; legs) were measured by dual-energy X-ray.

RESULTS

Higher dietary intake of total anthocyanidins (per one standard deviation increase) was associated with a 1.28-13.6 g (1.31-1.60%, compared to median) higher BMC at all sites and a 3.61-6.96 mg (0.65-0.90%) higher BMD at the whole body, WBEH, and arm sites after controlling for a number of possible covariates. The results were similar and more pronounced for cyanidin, but not for delphinidin and peonidin. Higher dietary intake of cyanidin (per one standard deviation increase) was associated with a 1.33-15.4 g (1.48-1.68%) higher BMC at all sites and a 4.15-7.77 mg (0.66-1.00%) higher BMD at all sites except the legs. No statistically significant associations with BMC or BMD were found for dietary intake of delphinidin and peonidin.

CONCLUSIONS

Higher dietary intake of total anthocyanidins and cyanidins were associated with higher BMC and BMD in Chinese children.

Relationship between bone mineral density and hyperuricemia in obesity: A cross-sectional study

BACKGROUND

Obesity is an increasingly severe global public health issue. This study aims to estimate the cross-sectional association between bone mineral density (BMD) and hyperuricemia (HU) in obesity.

METHOD

A total of 275 obese subjects (126 men and 149 women) participated in this cross-sectional study. Obesity was diagnosed as body mass index (BMI) ≥28 kg/m2, whereas HU was defined as the blood uric acid level of 416 μmol/L in men and 360 μmol/L in women. The BMD of the lumbar spine and right hip was measured by dual-energy X-ray absorptiometry (DXA). The multivariable logistic regressions were employed to examine the relationship between BMD and HU in obesity, with the adjustment of gender, age, fasting blood glucose, fasting insulin, homeostasis model assessment of insulin resistance (HOMA-IR), cholesterol, triglycerides, low-density lipoprotein, high-density lipoprotein, creatinine, blood urea nitrogen, high-sensitivity C-reactive protein (hs-CRP), cigarette smoking, and alcohol drinking status.

RESULT

The overall prevalence of HU was 66.9% in this obese population. The mean age and BMI of this population were 27.9 ± 9.9 years and 35.2 ± 5.2 kg/m2, respectively. The multivariable-adjusted OR (the highest vs. lowest BMD quartile) demonstrated a negative relationship between BMD and HU in total (OR = 0.415, 95%CI: 0.182-0.946; p = 0.036), L1 (OR = 0.305, 95%CI: 0.127-0.730; p = 0.008), L2 (OR = 0.405, 95%CI: 0.177-0.925; p = 0.032), and L3 (OR = 0.368, 95%CI: 0.159-0.851; p = 0.020) lumbar vertebrae. In the subgroup analysis for the male population, the BMD was also negatively associated with HU in total (OR = 0.077, 95%CI: 0.014-0.427; p = 0.003), L1 (OR = 0.019, 95%CI: 0.002-0.206; p = 0.001), L2 (OR = 0.161, 95%CI: 0.034-0.767; p = 0.022), L3 (OR = 0.186, 95%CI: 0.041-0.858; p = 0.031), and L4 (OR = 0.231, 95%CI: 0.056-0.948; p = 0.042) lumbar vertebrae. However, such findings did not exist in women. In addition, there was no significant relationship between hip BMD and HU in obesity.

CONCLUSION

Our results showed that the lumbar BMD was negatively associated with HU in obesity. However, such findings only existed in men, rather than women. In addition, no significant relationship between hip BMD and HU existed in obesity. Due to the limited sample size and nature of the cross-sectional design, further large prospective studies are still needed to clarify the issues.