The obesity indices mediate the relationships of blood lipids and bone mineral density in Chinese elders

Association between high-density lipoprotein cholesterol and lumbar bone mineral density in Chinese: a large cross-sectional study

BACKGROUND

The association between lipid and bone metabolism, particularly the role of high-density lipoprotein cholesterol (HDL-C) in regulating bone mineral density (BMD), is of significant interest. Despite numerous studies, findings on this relationship remain inconclusive, especially since evidence from large, sexually diverse Chinese populations is sparse. This study, therefore, investigates the correlation between HDL-C and lumbar BMD in people of different genders using extensive population-based data from physical examinations conducted in China.

METHODS

Data from a cross-sectional survey involving 20,351 individuals aged > = 20 years drawn from medical records of health check-ups at the Health Management Centre of the Henan Provincial People's Hospital formed the basis of this study. The primary objective was to determine the correlation between HDL-C levels and lumbar BMD across genders. The analysis methodology included demographic data analysis, one-way ANOVA, subgroup analyses, multifactorial regression equations, smoothed curve fitting, and threshold and saturation effect analyses.

RESULTS

Multifactorial regression analysis revealed a significant inverse relationship between HDL-C levels and lumbar BMD in both sexes, controlling for potential confounders (Male: β = -8.77, 95% CI -11.65 to -5.88, P < 0.001; Female: β = -4.77, 95% CI -8.63 to -0.90, P = 0.015). Subgroup and threshold saturation effect analyses indicated a stronger association in males, showing that increased HDL-C correlates with reduced lumbar BMD irrespective of age and body mass index (BMI). The most significant effect was observed in males with BMI > 28 kg/m2 and HDL-C > 1.45 mmol/L and in females with a BMI between 24 and 28 kg/m2.

CONCLUSION

Elevated HDL-C is associated with decreased bone mass, particularly in obese males. These findings indicate that individuals with high HDL-C levels should receive careful clinical monitoring to mitigate osteoporosis risk.

TRIAL REGISTRATION

The research protocol received ethics approval from the Ethics Committee at Beijing Jishuitan Hospital, in conformity with the Declaration of Helsinki guidelines (No. 2015-12-02). These data are a contribution of the China Health Quantitative CT Big Data Research team, registered at clinicaltrials.gov (code: NCT03699228).

Association between total cholesterol and lumbar bone density in Chinese: a study of physical examination data from 2018 to 2023

BACKGROUND

The impact of total cholesterol (TC) on lumbar bone mineral density (BMD) is a topic of interest. However, empirical evidence on this association from demographic surveys conducted in China is lacking. Therefore, this study aimed to examine the relationship between serum TC and lumbar BMD in a sample of 20,544 Chinese adults between the ages of 20 and 80 years over a period of 5 years, from February 2018 to February 2023. Thus, we investigated the effect of serum TC level on lumbar BMD and its relationship with bone reduction in a Chinese adult population.

METHODS

This cross-sectional study used data obtained from the Department of Health Management at Henan Provincial People's Hospital between February 2018 and February 2023. The aim of this study was to examine the correlation between serum TC and lumbar BMD in individuals of different sexes. The research methodology encompassed population description, analysis of stratification, single-factor and multiple-equation regression analyses, smooth curve fitting, and analysis of threshold and saturation effects. The R and EmpowerStats software packages were used for statistical analysis.

RESULTS

After adjusting for confounding variables, a multiple linear regression model revealed a significant correlation between TC and lumbar BMD in men. In subgroup analysis, serum TC was found to have a positive association with lumbar BMD in men, specifically those aged 45 years or older, with a body mass index (BMI) ranging from 24 to 28 kg/m2. A U-shaped correlation arose between serum TC and lumbar BMD was detected in women of different ages and BMI, the inflection point was 4.27 mmol/L for women aged ≥ 45 years and 4.35 mmol/L for women with a BMI of ≥ 28 kg/m2.

CONCLUSION

In this study, Chinese adults aged 20-80 years displayed different effects of serum TC on lumbar BMD in sex-specific populations. Therefore, monitoring BMI and serum TC levels in women of different ages could prevent osteoporosis and osteopenia.

TRIAL REGISTRATION

The research protocol was approved by the Ethics Committee of Beijing Jishuitan Hospital, in accordance with the Declaration of Helsinki guidelines (No. 2015-12-02). These data are part of the China Health Quantitative CT Big Data Research team, which has been registered at clinicaltrials.gov (code: NCT03699228).

The Paradoxical Association of Lipids with Survival and Walking Ability of Hip Fractures in Geriatric Patients After Surgery: A 1-Year Follow-Up Study

Background

We aimed to explore the association between lipids and the survival and walking ability of hip fractures in geriatric patients after surgery.

Methods

Restricted cubic spline (RCS) was established to explore the nonlinear relationship between lipids and 1-year mortality of hip fractures, and the cut-off points were also determined by RCS. Then, the patients were divided into three groups: low, middle, and high levels of LDL-c. Then, the survival and walking ability of patients from different groups were compared, and the Cox regression and Logistics regression were used to identify the relationships between lipids and the survival and walking ability of hip fractures.

Results

The patients with middle levels of LDL-c had a significantly high survival probability than those with low or high levels of LDL-c (p < 0.001). The patients with low levels of LDL-c and with high levels of LDL-c may have a poor prognosis compared with patients with middle levels of LDL-c in 6-month mortality, 6-month free walking ability, 1-year mortality, and 1-year free walking ability (All p < 0.05).

Conclusion

Low and high levels of LDL-c may both relate to the poor survival and walking ability of hip fractures.

The Casual Association Inference for the Chain of Falls Risk Factors-Falls-Falls Outcomes: A Mendelian Randomization Study

Previous associations have been observed not only between risk factors and falls but also between falls and their clinical outcomes based on some cross-sectional designs, but their causal associations were still largely unclear. We performed Mendelian randomization (MR), multivariate Mendelian randomization (MVMR), and mediation analyses to explore the effects of falls. Our study data are mainly based on White European individuals (40-69 years) downloaded from the UK Biobank. MR analyses showed that osteoporosis (p = 0.006), BMI (p = 0.003), sleeplessness (p < 0.001), rheumatoid arthritis (p = 0.001), waist circumference (p < 0.001), and hip circumference (p < 0.001) have causal effects on falls. In addition, for every one standard deviation increase in fall risk, the risk of fracture increased by 1.148 (p < 0.001), the risk of stroke increased by 2.908 (p = 0.003), and a 1.016-fold risk increase in epilepsy (p = 0.009). The MVMR found that sleeplessness is an important risk factor for falls. Finally, our mediation analyses estimated the mediation effects of falls on the hip circumference and fracture (p < 0.001), waist circumference and epilepsy (p < 0.001), and sleeplessness and fracture (p = 0.005). Our study inferred the causal effects between risk factors and falls, falls, and outcomes, and also constructed three causal chains from risk factors → falls → falls outcomes.

A Comparison Study on the Therapeutic Effect of High Protein Diets Based on Pork Protein versus Soybean Protein on Obese Mice

In this study, an obese C57BL/6J mice model was induced to compare the effect of different high protein diets (soybean protein and pork protein) on obesity. The obese mice were randomly divided into four groups: natural recovery (NR), high-fat diet (HF), high soybean protein diet (HSP), and high pork protein diet (HPP) groups. After 12 weeks of dietary intervention, the obesity-related indexes of mice were measured, such as body weight, fat coefficients, blood lipid indexes and so on. Results showed that HSP and HPP decreased the weight and fat coefficients of mice, the levels of serum total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C) and leptin (p < 0.05). Soybean protein was shown to be more effective in reducing the weight and fat mass of obese mice, although pork protein seemed to have a better effect on regulating serum triglyceride (TG). In addition, the two high protein diets both alleviated hepatic fat deposition effectively. Furthermore, HPP and HSP decreased the expression of hepatic peroxisome proliferator-activated receptor-γ (PPAR-γ) and increased the protein expression of phosphorylated AMP-activated protein kinase (pAMPK), phosphorylated acetyl CoA carboxylase (pACC), and uncoupling protein 2 (UCP2) (p < 0.05). In conclusion, the study shows that high protein diets based on both pork protein and soybean protein alleviated abdominal obesity in mice effectively by regulating lipid metabolism, probably via the UCP2-AMPK-ACC signaling pathway.