Triglyceride Levels and Fracture Risk in Midlife Women: Study of Women's Health Across the Nation (SWAN)

Risk factors for decreased bone mineral density in patients with metabolic dysfunction-associated steatotic liver disease: A cross-sectional study at a health examination center

BACKGROUND & AIMS

Steatotic liver disease (SLD) is often detected in health examinations. However, although individuals with metabolic dysfunction-associated SLD (MASLD) may have decreased bone mineral density (BMD), the specific risk factors remain unclarified. The objective of this study was to identify the factors associated with decreased BMD in patients with MASLD.

METHODS

Individuals who underwent abdominal ultrasonography and BMD measurements at our healthcare center were included. The BMD of the calcaneus was assessed using an AOS-10SA bone densitometer. Decreased BMD was defined as a T-score below -1.0 SD or the administration of osteoporosis treatment. SLD was diagnosed based on specific ultrasonographic criteria.

RESULTS

A total of 1410 patients were diagnosed with MASLD. The median age was 52 years. Multivariate analysis using a logistic regression model revealed that the independent predictors of decreased BMD were a low body mass index (BMI) or a small waist circumference (odds ratio (OR): 0.48, 95% confidence interval (CI): 0.34-0.67), hypertriglyceridemia (OR: 1.29, 95% CI: 1.00-1.65), and a weak grip strength (OR: 0.98, 95% CI: 0.97-1.00). Subgroup analyses of individuals aged 50 years or older, men, and individuals with a FIB-4 index of 1.3 or greater revealed that the absence of a high BMI or a large waist circumference was associated with decreased BMD. The subgroup analysis of men revealed that a weaker grip strength was associated with decreased BMD.

CONCLUSION

The present study suggested several potential risk factors for decreased BMD in patients with MASLD. Individuals with the abovementioned risk factors should be encouraged to undergo BMD measurement from the perspective of preventive medicine.

Correlation between bone density, bone metabolism markers with lipid metabolism markers and body mass index

PURPOSE

We aimed to explore the relationship between bone mineral density (BMD), bone metabolism markers, and blood lipid-related indicators, body mass index (BMI) in elderly individuals.

METHODS

A retrospective analysis was conducted on 710 patients. Patients' gender, age, height, weight, bone density values, T-scores, bone metabolism markers (including serum N-terminal propeptide of type I collagen (s-PINP), serum C-terminal telopeptide of type I collagen (s-CTX) and 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) and lipid-related indicators (including total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), triglycerides (TG) and Castelli index 1 (TC/HDL-C index) and Castelli index 2 (LDL-C/HDL-C index) were recorded. Correlations between variables were analyzed, and patients were grouped according to gender and T-score for intergroup comparisons.

RESULTS

HDL-C negatively correlates with BMD and s-CTX. TG, Castelli index, and BMI positively correlate with BMD. BMI negatively correlates with s-PINP. 1,25(OH)2D3 negatively correlates with TC, LDL-C, and Castelli index. LDL-C positively correlates with BMD in males, and TC negatively correlates with s-PINP. In females, HDL-C negatively correlates with BMD, and s-CTX positively correlates with Castelli index. 1,25(OH)2D3 negatively correlates with TC, LDL-C, and Castelli index. TG and Castelli index were higher in normal bone mass group, while HDL-C is higher in the osteoporosis group. TG and BMI positively predicted bone mass density, while HDL-C negatively predicted bone mass density.

CONCLUSIONS

HDL-C may have a predictive role in osteoporosis, particularly in women. The likelihood of osteoporosis is lower in individuals with high BMI or hyperlipidemia. Some lipid metabolism markers can be used to predict osteoporosis, and further research is needed.

Chronic alcohol and nicotine consumption as catalyst for systemic inflammatory storm and bone destruction in apical periodontitis

AIM

To assess the periapical alveolar bone pattern and the serum levels of proinflammatory cytokines, biochemical markers and metabolites in rats subjected to chronic alcohol and nicotine consumption and induced apical periodontitis.

METHODOLOGY

Twenty-eight male Wistar rats were divided into four groups: Control, Alcohol, Nicotine and Alcohol+Nicotine. The alcohol groups were exposed to self-administration of a 25% alcohol solution, while the other groups were given only filtered water. The nicotine groups received daily intraperitoneal injections of a nicotine solution (0.19 μL of nicotine/mL), whereas the other groups received saline solution. Periapical lesions were induced by exposing the pulps of the left mandibular first molars for 28 days. After euthanasia, the mandibles were removed and the percentage bone volume, bone mineral density, trabecular thickness, trabecular separation and trabecular number of the periapical bone were measured using micro-computed tomography images. Serum samples were collected for analysis of proinflammatory cytokines (IL-1β, IL-4, IL-6 and TNF-α), biochemical and metabolomic analysis. Statistical analysis was performed with a significance level of 5%. Nonparametric data were analysed using the Kruskal-Wallis test followed by Dunn's test, while one-way anova followed by Tukey's test was performed for parametric data.

RESULTS

The groups exposed to alcohol or nicotine consumption exhibited an altered bone pattern indicating lower bone density and higher levels of IL-1β, IL-6 and TNF-α compared to the Control group (p < .05). Significant differences were observed among the groups in the levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase, cholesterol, triglycerides, urea, creatinine, albumin, uric acid, bilirubin and calcium. Metabolomic analysis revealed significant differences in glycine, phosphocholine, lysine, lactate, valine, pyruvate and lipids (CH2 CH2 CO), n(CH2 ) and n(CH3 ). Most of these parameters were even more altered in the simultaneous consumption of both substances compared to single consumption.

CONCLUSION

Alcohol and nicotine chronic consumption altered several metabolic markers, impaired liver and kidney function, increased the production of systemic proinflammatory mediators and harmed the periapical bone microarchitecture in the presence of apical periodontitis. The simultaneous consumption of alcohol and nicotine intensified these detrimental effects.

The interplay between circulating high-density lipoprotein, age and fracture risk: a new cohort study and systematic meta-analysis

Previous findings on the association between high-density lipoprotein cholesterol (HDL-C) and fracture have yielded inconsistent results and it is unclear if the association varies with age and sex. We sought to evaluate the prospective association between HDL-C levels and fracture risk and assess if the association is modified by age and sex. Circulating HDL-C levels were measured at baseline in a population-based sample of 2,448 men aged 42-61 years. Cox regression was used to estimate hazard ratios (HRs) and 95% CIs. Incident fractures (n = 134) occurred during a median follow-up of 25.7 years. In analysis adjusted for several risk factors, the HR (95% CI) for fractures was 1.00 (0.85-1.20) per 1 standard deviation (SD) increase in HDL-C levels. Comparing the extreme tertiles of HDL-C levels, the corresponding adjusted HR (95% CI) was 0.94 (0.62-1.45). In a meta-analysis of eight cohort studies (including the current study) comprising 74,378 participants and 4,621 fracture cases, the fully-adjusted risk estimate (95% CI) for fracture was 1.03 (0.96-1.10) per 1SD increase in HDL-C levels and 1.05 (0.92-1.20) comparing extreme tertiles of HDL-C. The pooled risk estimate (95% CIs) for fracture per 1SD increase were 1.09 (1.01-1.17) and 0.98 (0.93-1.04) for age groups ≥ 60 and < 60 years, respectively, and the corresponding risks comparing the extreme tertiles of HDL-C levels were 1.21 (1.09-1.33) and 0.95 (0.85-1.07) (p-value for interaction < 0.05). Age may modify the association between HDL-C levels and fracture risk - an increased fracture risk associated with increased HDL-C levels is only evident in older age (≥ 60 years).

Association of Plasma High-Density Lipoprotein Cholesterol Level With Risk of Fractures in Healthy Older Adults

Importance

Increased levels of high-density lipoprotein cholesterol (HDL-C) have been associated with osteoporosis. Preclinical studies have reported that HDL-C reduces bone mineral density by reducing osteoblast number and function. However, the clinical significance of these findings is unclear.

Objective

To determine whether higher HDL-C levels are predictive of an increased fracture risk in healthy older adults.

Design, Setting, and Participants

This cohort study is a post hoc analysis of data from the Aspirin in Reducing Events in the Elderly (ASPREE) clinical trial and the ASPREE-Fracture substudy. ASPREE was a double-blind, randomized, placebo-controlled primary prevention trial of aspirin that recruited participants between 2010 and 2014. These comprised community-based older adults (16 703 Australians aged ≥70 years, 2411 US participants ≥65 years) without evident cardiovascular disease, dementia, physical disability, and life-limiting chronic illness. The ASPREE-Fracture substudy collected data on fractures reported postrandomization from Australian participants. Cox regression was used to calculate hazard ratio (HR) and 95% CI. Data analysis for this study was performed from April to August 2022.

Exposure

Plasma HDL-C.

Main Outcomes and Measures

Fractures included were confirmed by medical imaging and included both traumatic and minimal trauma fractures. Fractures were adjudicated by an expert review panel.

Results

Of the 16 262 participants who had a plasma HDL-C measurement at baseline (8945 female participants [55%] and 7319 male [45%]), 1659 experienced at least 1 fracture over a median (IQR) of 4.0 years (0.02-7.0 years). In a fully adjusted model, each 1-SD increment in HDL-C level was associated with a 14% higher risk of fractures (HR, 1.14; 95% CI, 1.08-1.20). The results remained similar when these analyses were stratified by sex. Sensitivity and stratified analyses demonstrated that these associations persisted when the analyses were repeated to include only (1) minimal trauma fractures, (2) participants not taking osteoporosis medications, (3) participants who were never smokers and reported that they did not drink alcohol, and (4) participants who walked outside for less than 30 minutes per day and reported no participation in moderate/vigorous physical activity and to examine only (5) statin use. No association was observed between non-HDL-C levels and fractures.

Conclusions and Relevance

This study suggests that higher levels of HDL-C are associated with an increased fracture risk. This association was independent of common risk factors for fractures.

Bone mineral density and lipid profiles in older adults: a nationwide cross-sectional study

It has been hypothesized that lipid profiles are associated with bone mineral density (BMD), but previous results have been controversial. In this study, serum triglycerides showed a significant inverse association with BMD, and the relationship is thought to correlate with vitamin D status among older adults.

INTRODUCTION

The purpose of this study was to investigate the relationship between lipid profiles and bone mineral density (BMD) in older adults using data from the Korean National Health and Nutrition Examination Survey (KNHANES).

METHODS

We enrolled men older than 50 years and postmenopausal women who participated in the KNHANES 2008-2011. Subjects with liver cirrhosis, thyroid disease, or renal dysfunction and those receiving treatment for hyperlipidemia or osteoporosis were excluded.

RESULTS

A total of 4323 subjects (2286 men and 2037 women) was analyzed. The prevalence of osteoporosis was 8.7% in men older than 50 years and 38.4% in postmenopausal women. Osteopenia and osteoporosis groups were generally older and tended to have a lower body mass index compared to the normal group (p for trend < 0.001). The correlation between each lipid profile and BMD was analyzed in the linear model adjusted for age and body mass index. Total cholesterol and high-density lipoprotein cholesterol showed a negative correlation with BMD in the total population, but there was no significant correlation when analyzed separately for men and women. Triglycerides had a negative association with whole-body BMD in both men and women (p < 0.05). The adjusted odds ratio of logarithmic triglyceride level for osteoporosis was 2.50 (95% confidence interval 1.13-5.51) in women older than 65 years.

CONCLUSION

Serum triglycerides showed a significant inverse association with BMD, and the relationship is thought to correlate with vitamin D status among older adults.

Major osteoporosis fracture prediction in type 2 diabetes: a derivation and comparison study

The widely recommended fracture prediction tool FRAX was developed based on and for the general population. Although several adjusted FRAX methods were suggested for type 2 diabetes (T2DM), they still need to be evaluated in T2DM cohort.

INTRODUCTION

This study was undertaken to develop a prediction model for Chinese diabetes fracture risk (CDFR) and compare its performance with those of FRAX.

METHODS

In this retrospective cohort study, 1730 patients with T2DM were enrolled from 2009.08 to 2013.07. Major osteoporotic fractures (MOFs) during follow-up were collected from Electronic Health Records (EHRs) and telephone interviews. Multivariate Cox regression with backward stepwise selection was used to fit the model. The performances of the CDFR model, FRAX, and adjusted FRAX were compared in the aspects of discrimination and calibration.

RESULTS

6.3% of participants experienced MOF during a median follow-up of 10 years. The final model (CDFR) included 8 predictors: age, gender, previous fracture, insulin use, diabetic peripheral neuropathy (DPN), total cholesterol, triglycerides, and apolipoprotein A. This model had a C statistic of 0.803 (95%CI 0.761-0.844) and calibration χ² of 4.63 (p = 0.86). The unadjusted FRAX underestimated the MOF risk (calibration χ² 134.5, p < 0.001; observed/predicted ratio 2.62, 95%CI 2.17-3.08), and there was still significant underestimation after diabetes adjustments. Comparing FRAX, the CDFR had a higher AUC, lower calibration χ², and better reclassification of MOF.

CONCLUSION

The CDFR model has good performance in 10-year MOF risk prediction in T2DM, especially in patients with insulin use or DPN. Future work is needed to validate our model in external cohort(s).

The Association of Lipids and Lipoproteins with Hip Fracture Risk: The Cardiovascular Health Study

BACKGROUND

It is uncertain if lipids or lipoproteins are associated with osteoporotic fractures. In this study, incident hip fracture risk according to conventional lipid levels and lipoprotein levels and sizes was examined.

METHODS

We followed 5832 participants aged ≥65 years from the Cardiovascular Health Study for hip fracture for a mean of 13.5 (SD 5.7) years. Standard enzymatic methods were used to determine lipid levels (ie, high-density lipoprotein-cholesterol [HDL-c], low-density lipoprotein-cholesterol [LDL-c], and triglycerides). Nuclear magnetic resonance spectroscopy was used to measure lipoprotein fractions (ie, very-low-density lipoprotein-particle [VLDL-P], low-density lipoprotein-particle [LDL-P], high-density lipoprotein-particle [HDL-P]) in a subset of 1849 participants.

RESULTS

We documented 755 incident hip fractures among women (1.19 fractures per 100 participant years [95% confidence interval, 1.04, 1.35]) and 197 among men (0.67 fractures per 100 participant years [95% CI, 0.41, 1.10]) over an average follow-up. HDL-c and LDL-c levels had statistically significant nonlinear U-shaped relationships with hip fracture risk (HDL-c, P = .009; LDL-c, P = .02). Triglyceride levels were not significantly associated with hip fracture risk. In fully adjusted conjoint models, higher VLDL-P concentration (hazard ratio [HR] per 1 standard deviation [SD] increment 1.47 [1.13, 1.91] and size [HR per 1 SD increment 1.24 [1.05, 1.46]) and higher high-density lipoprotein particle size (HR per 1 SD increment 1.81 [1.25, 2.62]) were all associated with higher hip fracture risk.

CONCLUSIONS

Lipids and lipoproteins are associated with hip fracture risk in older adults. The associations are complex. Mechanistic studies are needed to understand these findings.

Association of different lipid measures with incident bone fractures: Tehran Lipid and Glucose Study

OBJECTIVE

to investigate the association between different lipid measures and long-term hospitalization-required incident fracture among Iranian men and women.

METHODS

A total of 3309 individuals aged ≥50 years (men = 1598) were included in the study. Multivariate Cox proportional hazard analyses were performed to assess the risk of incident fracture across quintiles, considering first quintile as reference, as well as for 1-standard deviation (SD) increase in each lipid measures i.e. total cholesterol (TC), triglycerides (TG), low and high density lipoprotein cholesterol (LDL-C and HDL-C, respectively), non-HDL-C, and related indices (TG/HDL-C and TC/HDL-C). Covariates included age, body mass index, current smoking, type 2 diabetes mellitus, hypertension, lipid lowering-drugs, and steroid medications (for women).

RESULTS

During a median follow-up of 18 years, incident fracture was observed in 201 cases (men=87). In both gender no linear association were found between different lipid measures and incident fracture. Among men only the fourth quartile of TG was associated with lower risk of fracture in the age adjusted analysis with hazard ratio (HR) and 95% confidence interval (CI) as [0.45 (0.21-0.95)]. Among women, the age-adjusted HRs and 95% CIs for the second, third, fourth and fifth quintiles of non-HDL-C were [0.46 (0.25-0.87)], [0.73 (0.42-1.25)], [0.90 (0.54-1.51)], [0.52 (0.29-0.95)], respectively; the corresponding values in the multivariate model, were [[0.48 (0.26-0.90)], [0.76 (0.4-1.32)], [0.94 (0.56-1.58)], and [0.52 (0.28-0.95)], respectively. The second quintile of LDL-C was also associated with lower risk for incident fracture in the multivariate analysis [0.53 (0.29-0.98)].

CONCLUSIONS

Among Iranian women a nonlinear association between non-HDL-C and LDL-C and incident fracture were found as the second and fifth quintile of the former and the second quintile of the latter were associated with about 50% lower risk of fracture .Generally our findings did not support harmful impact of these lipid measures on incident fracture.

Plasma lipidomics analysis reveals altered lipids signature in patients with osteonecrosis of the femoral head

INTRODUCTION

Although studies have established a link between lipid metabolism disorder and osteonecrosis of the femoral head (ONFH), the characteristics of the circulating lipidome signature of ONFH have not yet been investigated and need to be explored.

OBJECTIVES

We aimed to explore the plasma lipidome signatures in patients with ONFH, and to identify specific lipid biomarkers of ONFH.

METHODS

In this study, a comprehensive detection and analysis of plasma lipidomics was conducted in clinical human cohort, including 32 healthy normal control (NC) subjects and 91 ONFH patients in different subgroups [alcohol-induced ONFH (AONFH), steroid-induced ONFH (SONFH), and traumatic-induced ONFH (TONFH)] or at different disease stages (stage I, II, III and IV of ONFH) using ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS).

RESULTS

Overall, the plasma lipidome profile differs between ONFH and NC samples. Lipidome signature including 22 common differentially expressed lipids (DELs) in all three subgroups (variable importance in projection > 1, P < 0.05, fold change > 1.5 or < 0.67, compared to the NC group) was identified. Besides, the subtype-specific lipidome profiles for each ONFH subgroup were also analyzed. Generally, the AONFH subgroup has the largest number of DELs, and the plasma levels of triacylglycerol lipid compounds increased obviously in the AONFH samples. In the subgroup of SONFH, the relative abundance of lipid 4-Aminobenzoic acid increased significantly with changes in the expression of several of its interactive genes. We have identified that 9 stage-positive and 2 stage-negative lipids may function as novel biomarkers predicting the progression of ONFH.

CONCLUSION

Our study presents an overview of the phenotype-related plasma lipidome signature of patients with ONFH. The results will provide insight into the mechanisms underlying the metabolism of lipids in the pathogenesis and progression of ONFH and help identify novel lipids biomarkers or disease diagnosis and treatment targets.

Serum 25(OH)D Levels Modify the Association between Triglyceride and IR: A Cross-Sectional Study

BACKGROUND

Triglycerides and 25(OH)D had been reported as correlates of IR, but the results suggest substantial heterogeneity across races. In addition, little research reported on whether different 25(OH)D levels affect triglycerides and IR. Therefore, a similar study on the US population would be a great addition to the current one. This study investigated the association between triglycerides and IR at different 25(OH)D levels.

METHODS

A total of 19,926 participants were included, each containing specific indicators for the study project. IR was estimated as a HOMA-IR index ≥2.73. Four multivariate logistic regression models were developed to analyze the association between TG and IR and whether different 25(OH)D levels influenced this association. Smoothed fitting curves were plotted.

RESULTS

Triglyceride was significantly associated with IR (OR: 1.3, 95 CI %), while this association received different 25(OH)D levels (P for interaction <0.001). The effect value OR was 1.33 with the high levels, and its effect value OR was 1.28 with the low levels.

CONCLUSION

This study demonstrates that triglyceride levels are significantly associated with insulin in the US adult population and can be used as a predictor of IR. This correlation was compromised at different 25 (OH)D levels, so future studies need to be explored in more ethnically diverse contexts.

Dairy intake is not associated with improvements in bone mineral density or risk of fractures across the menopause transition: data from the Study of Women's Health Across the Nation

Objective:

Menopause represents a period in which bone deterioration is accelerated; thus, primary prevention strategies to address age-related bone loss are crucial. Dairy products contain more than a dozen essential nutrients, including calcium, phosphorus, vitamin D, and high-quality protein, as well as bioactive compounds that may promote bone mineralization. However, the relationship between dairy consumption and bone health across the menopause transition remains largely unknown. The purpose of this analysis was to estimate the change in lumbar spine and femoral neck bone mineral density and the risk of bone fracture by the frequency of dairy intakes among women across the menopausal transition using the publicly available data from the Study of Women's Health Across the Nation.

Methods:

We analyzed total dairy foods in four categories of <0.5, 0.5 to <1.5, 1.5 to <2.5, and ≥2.5 servings/d or <1.5 and ≥1.5 servings/d. A general linear model was used to estimate the association of dairy intake with the 10-year bone mineral density loss rate and a linear mixed model was used to estimate the annualized bone mineral density loss rate of the femoral neck and lumbar spine. A Cox proportional hazard model was applied to calculate hazard ratios and 95% confidence intervals of the nontraumatic fractures. Poisson regression was used to determine the relative risks and 95% confidence intervals of the nontraumatic fractures. The models were controlled for race/ethnicity, age, height, weight, smoking status, physical activity, alcohol consumption, calcium use, menopausal status, and total caloric intake.

Results:

No significant differences in bone mineral density change were observed, regardless of baseline menopausal status. No significant differences in the risk of nontraumatic fracture were observed.

Conclusions:

In this group of US women undergoing the menopausal transition, dairy food intake was neither associated with femoral and spine bone mineral density loss nor the risk of fractures.

The Role of Metabolic Syndrome and its Components in Incident Fracture: A 15-Year Follow-Up Among the Iranian Population

CONTEXT

The relationship between metabolic syndrome (MetS) and the risk of fracture is a matter of debate.

OBJECTIVE

This work aimed to determine the impact of MetS and its components on the risk of hospitalized fractures, during a median follow-up of 15.9 years.

METHODS

A total of 7,520 participants (4,068 women) 30 years or older entered the study. Multivariable Cox proportional hazards regression were applied for data analysis.

RESULTS

The prevalence of MetS was 40.0% and 40.4% in men and women, respectively. During the follow-up, hospitalized fracture was observed in 305 cases (men = 152). The multivariable hazard ratio (HR) and 95% confidence interval (CI) of MetS for incident fracture for men and women was 0.72 (0.49-1.05, P = .08) and 1.38 (0.96-1.98, P = .08), respectively. In the fully adjusted model, high fasting plasma glucose (FPG) among men tended to be associated with a lower risk of fracture [0.67 (0.44-1.02, P = .06)]; among women, high waist circumference (WC) was associated with a greater risk [2.40 (1.55-3.73)]. Among the population 50 years and older in the pooled sample, MetS was not accompanied by the risk of fracture, but high WC was associated with a higher risk [1.58 (1.07-2.33)]. For incident hip/pelvic fracture, abdominal obesity-but not MetS per se-was also a strong and independent risk factor.

CONCLUSION

A significant sex difference in the association between MetS and its components with incident fracture was observed. Women with central adiposity were at increased risk of hospitalized fracture, whereas men with high FPG were at decreased risk.

Two adipocytokines, leptin and adiponectin, independently predict osteoporotic fracture risk at different bone sites in postmenopausal women

Although associations among obesity, adipocytokines, and bone mineral density have been reported, the influence of adipocytokines on osteoporotic fractures remains unclear. This study aimed to assess the impact of the adipocytokines leptin and adiponectin on the risk of incident vertebral and long-bone fractures in postmenopausal women. Clinical data were obtained from the retrospective Nagano Cohort Study of outpatients followed at a single primary care institute in Nagano Prefecture, Japan, between 1993 and 2018. The primary outcome was the occurrence of incident vertebral or long-bone fractures. In total, 1167 Japanese postmenopausal women (mean age: 65.9 years) completed the follow-up and the average observation period was 7.2 years. The subjects were divided into 4 groups (quartile 1 to 4) based respective leptin and adiponectin values. Kaplan-Meier analysis demonstrated a significantly lower incident long-bone fracture rate in the higher quartiles of serum leptin levels (p = 0.002). A significantly higher and more rapid occurrence of incident vertebral fractures, but not long-bone fractures, was found in the highest adiponectin quartile (p < 0.001). A Cox proportional hazards model adjusted for confounders including age, body weight, and either leptin or adiponectin revealed lower leptin levels and higher adiponectin levels as significant independent risk factors for incident long-bone fractures (hazard ratio [HR] 0.70, 95% confidence interval [CI] 0.50-0.96; p = 0.03) and vertebral fractures (HR 1.18, 95% CI 1.02-1.37; p = 0.02), respectively. Therefore, serum leptin and adiponectin may be independent risk factors for osteoporotic fractures affecting different bone types and sites. Determining patient adipocytokine levels may help predict the occurrence of specific osteoporotic fractures, thereby enabling optimal treatment for osteoporosis and improving quality of life.

Are blood lipids risk factors for fracture? Integrative evidence from instrumental variable causal inference and mediation analysis using genetic data

BACKGROUND

The relationship between lipids and the risk of fracture is currently controversial and whether such association is causal remains elusive.

METHODS

We performed two-sample inverse variance weighted (IVW) Mendelian randomization (MR) analyses to evaluate causal effects of four lipids (i.e. high-density lipoprotein cholesterol [HDL], low-density lipoprotein cholesterol [LDL], total cholesterol [TC] and triglyceride [TG]) on fracture or bone mineral density (BMD) with summary statistics from large scale genome-wide association studies (up to ~190,000 for lipids, ~66,628 for BMD and ~53,000 for fracture). We validated our MR results with extensive sensitive analyses including MR-PRESSO and MR-Egger regression. Multivariable analyses were implemented to investigate whether other lipids (i.e. LDL and TG) may confound the causal effect of HDL on fracture and mediation analyses were conducted to assess indirect effects of lipids on fracture mediated by BMD.

RESULTS

The IVW MR showed there existed a statistically significant association between HDL and fracture, with the odd ratio (OR) per standard deviation change of HDL on fracture being 1.12 (95% CI: 1.02-1.22, p = 1.20E-02). HDL was also detected to be causally associated with BMD (beta = -0.116; 95% CI: -0.182 ~ -0.050, p = 5.47E-04). These associations were further confirmed by the weighted median and maximum likelihood methods, with the MR-Egger regression removing the possibility of pleiotropy and the multivariable analysis excluding the confounding effect of other lipids on HDL. Negative associations of HDL with BMD among the elderly and with BMD at the lumbar spine were also discovered. However, no causal associations were detected between other lipids (OR = 0.87, 95% CI: 0.74-1.03, p = .107 for LDL; OR = 1.03; 95% CI: 0.88-1.21, p = .696 for TC and OR = 1.04; 95% CI: 0.90-1.20, p = .610 for TG) and fracture; whereas TG was positively associated BMD (beta = 0.184; 95% CI: 0.048-0.319, p = 7.93E-03). Finally, the mediation effect of BMD was estimated to be -0.116 (95% CI: -0.182 to -0.05, p = 5.47E-04) for HDL or 0.184 (95% CI: 0.048-0.319, p = 7.93E-03) for TG, implying HDL and TG could be indirectly associated with fracture risk via the pathway of BMD.

CONCLUSION

Our study is supportive of the causal relationship between HDL and fracture but offers little direct evidence for causal associations between other lipids and fracture, and further reveals HDL and TG may have an indirect influence on fracture mediated by BMD.

Lipid Profile and Risk of Bone Fracture: A Systematic Review and Meta-Analysis of Observational Studies

Purpose: Earlier studies have linked lipid profile to osteoporotic fractures; however, to our knowledge, no study had summarized available data on this relationship. We aimed to summarize the current evidence on the association between lipid profile and bone fractures. Material and Methods: A systematic search of PubMed and Scopus was done to find relevant published studies until March 2018. To combine effect sizes, we applied fixed- or random-effects analysis, where appropriate. Cochran's Q test and I² were used to assess between-study heterogeneity. Results: Overall, 11 studies (seven prospective, three cross-sectional and one case-control studies) were included in the current systematic review. Out of them, 10 studies with a total sample size of 60,484 individuals, aged 25 years or more, were used in the meta-analysis. The results showed that total cholesterol concentration was positively associated with risk of bone fracture; such that a 50-mg/dl increase in plasma level of TC was associated with 15% greater odds of bone fracture (combined effect size: 1.15, 95% CI: 1.02-1.30, P = .02). Furthermore, we found that individuals with a decreased level of HDL (<40 mg/dl) had a lower risk of bone fracture compared with those with a normal level (≥40 mg/dl) (combined effect size: 0.82, 95% CI: 0.71-0.96, P = .01). No significant association was found between plasma level of TG and LDL with the risk of bone fractures either in prospective or cross-sectional studies. Conclusions: We found that plasma levels of total cholesterol were positively associated with bone fractures. In addition, decreased levels of HDL were associated with an increased risk of osteoporotic fractures. Abbreviations: TG: triglycerides, TC: total cholesterol, HDL: high-density lipoprotein, LDL: low-density lipoprotein, OR: odds ratio, RR: relative risk, HR: hazard ratio, DXA: dual-energy X-ray absorptiometry, ICD: International Classification of Diseases, SD: standard deviation.

Causal link between lipid profile and bone mineral density: A Mendelian randomization study

The level of serum lipids is associated with bone mineral density (BMD), an important skeletal trait. Yet the causality has not been determined. Here we performed a Mendelian randomization (MR) analysis to test potential causal links between BMD and lipid profile, i.e., low-density lipoprotein cholesterol (LDC-c), total cholesterol (TC), triglyceride (TG) and high-density lipoprotein cholesterol (HDL-c). We observed causal effect of LDL-c, TC and TG to BMD, and reversely the effect of BMD to HDL-c. We further explored the effect of body mass index (BMI) in these causalities and found that the effect of LDL-c, TC and TG to BMD is independent of BMI. Our findings provided useful information in the clinical relevance of blood lipids on BMD variation and osteoporosis risk.

Lipoprotein(a) plasma levels, bone mineral density and risk of hip fracture: a post hoc analysis of the Women's Health Initiative, USA

OBJECTIVES

Elevated Lipoprotein(a) (Lp[a]) is a well-known risk factor for cardiovascular disease. However, its roles in bone metabolism and fracture risk are unclear. We therefore investigated whether plasma Lp(a) levels were associated with bone mineral density (BMD) and incident hip fractures in a large cohort of postmenopausal women.

DESIGN

Post hoc analysis of data from the Women's Health Initiative (WHI), USA.

SETTING

40 clinical centres in the USA.

PARTICIPANTS

The current analytical cohort consisted of 9698 white, postmenopausal women enrolled in the WHI, a national prospective study investigating determinants of chronic diseases including heart disease, breast and colorectal cancers and osteoporotic fractures among postmenopausal women. Recruitment for WHI took place from 1 October 1993 to 31 December 1998.

EXPOSURES

Plasma Lp(a) levels were measured at baseline.

OUTCOME MEASURES

Incident hip fractures were ascertained annually and confirmed by medical records with follow-up through 29 August 2014. BMD at the femoral neck was measured by dual X-ray absorptiometry in a subset of participants at baseline.

STATISTICAL ANALYSES

Cox proportional hazards and logistic regression models were used to evaluate associations of quartiles of plasma Lp(a) levels with hip fracture events and hip BMD T-score, respectively.

RESULTS

During a mean follow-up of 13.8 years, 454 incident cases of hip fracture were observed. In analyses adjusting for confounding variables including age, body mass index, history of hysterectomy, smoking, physical activity, diabetes mellitus, general health status, cardiovascular disease, use of menopausal hormone therapy, use of bisphosphonates, calcitonin or selective-oestrogen receptor modulators, baseline dietary and supplemental calcium and vitamin D intake and history of fracture, no significant association of plasma Lp(a) levels with low hip BMD T-score or hip fracture risk was detected.

CONCLUSIONS

These findings suggest that plasma Lp(a) levels are not related to hip BMD T-score or hip fracture events in postmenopausal women.

TRIAL REGISTRATION NUMBER

NCT00000611; Post-results.

Bone Health During the Menopause Transition and Beyond

The menopause transition is a critical period for bone health, with rapid losses in bone mass and strength occurring in a 3-year window bracketing the date of the final menstrual period. Declines in bone mass are accompanied by deleterious changes in bone macrostructure and microarchitecture, which may be captured by changes in composite strength indices and indices of trabecular thickness and connectivity. The onset of the rapid bone loss phase is preceded by changes in sex steroid hormones and increases in markers of bone resorption, measurements of which may be clinically useful in predicting the onset of the rapid loss phase and in identifying the women who will lose the most bone strength over the menopause transition.