Association of covert brain infarcts and white matter hyperintensities with risk of hip fracture in older adults: the Cardiovascular Health Study

Estimated bone mineral density and white matter hyperintensities: A bidirectional Mendelian randomization study

PURPOSE

Greater white matter hyperintensities (WMH) in older adults have been associated with reduced bone mineral density (BMD) and increased fractures and falls. However, it is unclear whether there is a causal relationship between BMD reduction and WMH. In this study, Mendelian randomization (MR) was used to find the causality between WMH and estimated BMD (eBMD).

METHODS

We performed a two-sample bidirectional MR analysis using statistical data obtained from publicly available genome-wide association studies (GWAS). The main method of MR analysis is the inverse-variance weighted (IVW) method. To identify and account for the impact of horizontal pleiotropy, we also employed MR-Egger regression, MR pleiotropy residual sum, and outlier (MR-PRESSO).

RESULTS

MR analysis found a causal relationship between eBMD and WMH (IVW OR = 0.938, 95 % CI: 0.889-0.990, p = 0.020). Our causal estimates are unlikely to be distorted by horizontal pleiotropy according to heterogeneity test (both p > 0.05) and MR-Egger regression (p > 0.05). However, in the reverse MR analysis, there was no evidence that WMH was causally correlated with eBMD (IVW OR = 0.979, 95 % CI: 0.954-1.005, p = 0.109).

CONCLUSION

Our results suggest that low eBMD increased the risk of WMH; conversely, no evidence that WMH causally affects eBMD was found.

Association of white matter hyperintensities with BMD, incident fractures, and falls in the UK Biobank cohort

Osteoporosis is the most common metabolic bone disease globally, which increases the healthcare service burden. Recent studies have linked higher white matter hyperintensities (WMH) to reduced BMD, increasing the risk of fractures and falls in older adults. However, limited evidence exists regarding the dose-response relationship between WMH and bone health in a larger and younger population. Our study aimed to examine the association of WMH volume with BMD, incident fractures and falls, focusing on dose-response relationship with varying levels of WMH volume. We included 26 410 participants from the UK Biobank. The association between WMH volume and BMD was analyzed using multiple linear regression. Cox regression models were used to estimate the hazard ratios of incident fractures and falls. Restricted cubic spline (RCS) fitted for linear and Cox regression models were employed to explore potential non-linearity. Over a mean follow-up time of 3.8 yr, we documented 59 hip fractures, 392 all fractures, and 375 fall incidents. When applying RCS, L-shaped relationships were identified between WMH volume and BMD across all 4 sites. Compared with those in the lowest fifth of WMH volume, individuals in the second to the highest fifths were associated with a reduction of 0.0102-0.0305 g/cm2 in femur neck BMD, 0.0075-0.0273 g/cm2 in femur troch BMD, 0.0173-0.0345 g/cm2 in LS BMD, and 0.0141-0.0339 g/cm2 in total body BMD. The association was more pronounced among women and younger participants under age 65 (Pinteraction < .05). Per 1 SD increment of WMH volume was associated with 36.9%, 20.1%, and 14.3% higher risks of incident hip fractures, all fractures, and falls. Genetically determined WMH or apolipoprotein E genotypes did not modify these associations. We demonstrated that a greater WMH was associated with BMD in an L-shaped dose-response manner, especially in women and those under 65 yr.

Association between osteoporosis and cardiovascular disease in elderly people: evidence from a retrospective study

Objective

This study aimed to investigate the associations between osteoporosis, biochemical indexes, bone mineral density (BMD), and cardiovascular disease.

Methods

A cross-sectional study design was used to examine the relationships between these parameters. Logistic regression and correlation analyses were conducted to assess the associations between elevated levels of triglyceride, total cholesterol, low-density lipoprotein (LDL), high-density lipoprotein (HDL), homocysteine, and the presence of osteoporosis. Additionally, correlations between BMD and biochemical indexes were analyzed. The incidence of cardiovascular disease and its correlation with BMD were evaluated. Receiver operating characteristic (ROC) analysis was performed to determine the utility of BMD in identifying cardiovascular disease.

Results

The results revealed that elevated triglyceride, total cholesterol, and LDL levels were positively associated with osteoporosis, while higher HDL levels and homocysteine were negatively associated. Correlation analysis demonstrated negative correlations between triglyceride levels and BMD, and positive correlations between total cholesterol and HDL levels with BMD. LDL levels showed a weak negative correlation, and homocysteine levels exhibited a strong negative correlation with BMD. The osteoporosis group had lower BMD and a higher incidence of cardiovascular disease compared to the non-osteoporosis group. Logistic regression analysis confirmed the correlation between lower BMD and increased risk of cardiovascular disease.

Conclusion

This study provides evidence supporting the associations between osteoporosis, biochemical indexes, BMD, and cardiovascular disease. Aberrations in lipid profiles and homocysteine levels may contribute to osteoporosis development. Lower BMD, particularly in individuals with osteoporosis, appears to increase the risk of cardiovascular disease. BMD shows promise as a diagnostic tool for identifying individuals at risk of cardiovascular disease. Further research is needed to elucidate the underlying mechanisms and establish the clinical implications of these relationships. Future longitudinal studies are necessary to determine causality and long-term prognostic implications.