Background: Dyslipidemia has been found to contribute to increased risk of osteoporosis and its association with bone mineral density (BMD) remains controversial. We determined whether blood lipid levels are linked with change of BMD. Methods: In a large sample from the MIDUS II study, we sought to evaluate the relationship between blood lipid levels and BMD. Multivariate linear regression models and smooth curve analysis were constructed by controlling a great range of confounding factors. Results:The median age of them was 52.5 years, and the number of males was 176 (40%). Univariate analysis showed that blood high-density lipoprotein-cholesterol (HDL-C) level was negatively related to lunar total femur (r = −0.266, P < 0.001), lunar radius ultradistal (UD) (r = −0.297, P < 0.001), lunar radius 1/3 (r = −0.307, P = 0.001) and femoral neck (r = −0.172, P = 0.001). In multivariate linear analysis, except for blood triglyceride, total cholesterol and low-density lipoprotein cholesterol (LDL-C), we found that blood HDL-C level was still negatively related to lunar total femur [B = −0.002, B 95% CI (−0.002, −0.001), P < 0.001], lunar radius UD [B = −0.001, 95% CI (−0.001, 0), P = 0.002], lunar radius 1/3 [B = −0.001, 95% CI (−0.001, 0), P = 0.003] and femoral neck [B = −0.001, 95% CI (−0.002, 0), P = 0.039] after adjustments of demographic characteristics, lifestyle, disease history were made. Furthermore, we found that age, sex, and body mass index (BMI) had modifying effects on this negative association. Conclusion:This study confirmed the negative association between HDL-C and BMD in the observational analysis from (MIDUS) study and provides high-quality evidence that age, sex and BMI had modifying effects on this negative association.

Background Studies have confirmed that antioxidants contribute to a lower risk of osteoporosis, which is an independent factor for femoral neck fracture (FNF). However, the associations between blood antioxidant levels and femoral neck strength remain unclear. Objective Our aim was to test the hypothesis that levels of blood antioxidants are positively associated with composite indices of bone strength in femoral neck, which integrate the bending strength index (BSI), compressive strength index (CSI), and impact strength index (ISI), in a population of middle-aged and elderly individuals. Methods This cross-sectional study utilized data from the Midlife in the United States (MIDUS) study. Blood levels of antioxidants were measured and analyzed. Results In total, data from 878 participants were analyzed. Results of Spearman correlation analyses indicated that blood levels of 6 antioxidants (total lutein, zeaxanthin, alpha-carotene, 13-cis-beta-carotene, trans-beta-carotene and total lycopene) were positively associated with CSI, BSI, or ISI in middle-aged and elderly individuals. Conversely, blood gamma-tocopherol and alpha-tocopherol levels were negatively associated with CSI, BSI, or ISI scores. Furthermore, linear regression analyses suggested that only blood zeaxanthin levels remained positively associated with CSI (odds ratio, OR 1.27; 95% CI: 0.03, 2.50; p = 0.045), BSI (OR, 0.54; 95% CI: 0.03–1.06; p = 0.037), and ISI (OR, 0.06; 95% CI: 0.00, 0.13; p = 0.045) scores in the study population after adjusting for age and sex. Conclusions Our results indicated that elevated blood zeaxanthin levels were significantly and positively associated with femoral neck strength (CSI, BSI, or ISI) in a population of middle-aged and elderly individuals. These findings suggest that zeaxanthin supplementation may reduce FNF risk independently.