Impact of dyslipidemia on the severity of symptomatic lumbar spine degeneration: A retrospective clinical study

Mediating effect of metabolic syndrome in the association of educational attainment with intervertebral disc degeneration and low back pain

The causal association of educational attainment (EA) with intervertebral disc degeneration (IVDD) or low back pain (LBP), and the mediating effect of metabolic syndrome (MetS) in this association, is not studied to date. In this study, using summary statistics of genome-wide association studies primarily conducted in the individuals of European ancestry, Mendelian randomization (MR) analyses were performed to investigate: (1) the total and direct effects of EA on IVDD and LBP, (2) bidirectional associations of EA with MetS or the components of MetS, (3) causal effects of MetS or its components on IVDD and LBP, and (4) mediating effects of MetS or its components on the causal associations of EA with IVDD and LBP. Univariable MR analysis demonstrated that genetically proxied EA was inversely associated with IVDD (ORIVW: 0.90; 95 % CI: 0.87-0.92) and LBP (ORIVW: 0.86; 95 % CI: 0.84-0.89). Consistent results were obtained after adjusting for potential confounders (cognition, economic level, smoking traits, and metabolic factors). Mediation analysis proved that the effect of EA on IVDD mediated by MetS, waist circumference, and high-density lipoprotein cholesterol was 11.38 %, 9.22 %, and 2.17 %, respectively. Besides, MetS mediated 8.42 % and waist circumference mediated 5.81 % of the EA effects on LBP, respectively. Our findings provided support for MetS mediating the causal protective effects of EA on IVDD and LBP, which provided causal evidence to the etiology and intervention targets of IVDD and LBP.

Bioenergetic dysfunction in the pathogenesis of intervertebral disc degeneration

Intervertebral disc (IVD) degeneration is a frequent cause of low back pain and is the most common cause of disability. Treatments for symptomatic IVD degeneration, including conservative treatments such as analgesics, physical therapy, anti-inflammatories and surgeries, are aimed at alleviating neurological symptoms. However, there are no effective treatments to prevent or delay IVD degeneration. Previous studies have identified risk factors for IVD degeneration such as aging, inflammation, genetic factors, mechanical overload, nutrient deprivation and smoking, but metabolic dysfunction has not been highlighted. IVDs are the largest avascular structures in the human body and determine the hypoxic and glycolytic features of nucleus pulposus (NP) cells. Accumulating evidence has demonstrated that intracellular metabolic dysfunction is associated with IVD degeneration, but a comprehensive review is lacking. Here, by reviewing the physiological features of IVDs, pathological processes and metabolic changes associated with IVD degeneration and the functions of metabolic genes in IVDs, we highlight that glycolytic pathway and intact mitochondrial function are essential for IVD homeostasis. In degenerated NPs, glycolysis and mitochondrial function are downregulated. Boosting glycolysis such as HIF1α overexpression protects against IVD degeneration. Moreover, the correlations between metabolic diseases such as diabetes, obesity and IVD degeneration and their underlying molecular mechanisms are discussed. Hyperglycemia in diabetic diseases leads to cell senescence, the senescence-associated phenotype (SASP), apoptosis and catabolism of extracellualr matrix in IVDs. Correcting the global metabolic disorders such as insulin or GLP-1 receptor agonist administration is beneficial for diabetes associated IVD degeneration. Overall, we summarized the recent progress of investigations on metabolic contributions to IVD degeneration and provide a new perspective that correcting metabolic dysfunction may be beneficial for treating IVD degeneration.

Lumbar disc herniation is an independent predictor of plaque burden in the patients with unstable angina

Objective

Assessing the impact of lumbar disc herniation (LDH) on the plaque burden of coronary atherosclerosis is our objective.

Methods

In this study, a total of 212 patients (age 46-80 years) with unstable angina (UA) who underwent coronary angiography (CAG) in our hospital from January 2018 to July 2022 due to UA were included. Patients were divided into LDH group (n = 106) and no LDH group (n = 106). Gensini scores were calculated to assess the plaque burden of coronary. Logistic analysis was used to examine potential risk variables linked to the Gensini score. The association between lumbar disc lesions grading and coronary plaque burden was analysed by Spearman's correlation test. LDH patients with higher plaque burden (n = 56) were further divided into evolocumab treatment group (n = 28) and conventional treatment group (n = 28). Cox regression analysis were performed.

Results

Patients with LDH had higher Gensini scores (P < 0.01) and triglyceride (TG) levels (P = 0.04), but HDL-C (P = 0.01) levels were lower. LDH was found to be an independent risk factor for higher Gensini scores (OR = 2.38, P < 0.01) by logistic analysis. The Spearman's correlation test suggested that the degree of lumbar disc lesions was related to the Gensini score and the level of blood lipid. Cox regression analysis showed that evolocumab treatment could significantly reduce the composite MACE events (cardiac death, nonfatal myocardial infarction, nonfatal stroke, and readmission due to angina) (HR = 0.26, P = 0.04) in higher coronary plaque burden patients.

Conclusion

LDH is an independent risk factor for the higher coronary plaque burden. Evolocumab treatment significantly reduced the occurrence of cardiovascular events in LDH patients with higher plaque burden. Additionally, our data indicate that LDH is associated with increased blood lipid, which may contribute to the development of plaque burden.

Dyslipidemia Is Positively Associated with Chronic Low Back Pain in Korean Women: Korean National Health and Nutrition Examination Survey 2010-2012

BACKGROUND

This study aimed to evaluate the association between chronic low back pain (CLBP) and chronic diseases, such as hypertension, diabetes, and dyslipidemia.

METHODS

This study was a retrospective analysis using data from the Korea National Health and Nutrition Examination Survey (KNHANES) between 2010-2012 and included women who answered a questionnaire in the KNHANES asking whether they had low back pain for ≥3 months. Participants were divided into non-CLBP and CLBP groups. For statistical analysis, the Student's t-test, chi-square test, Fisher's exact test, and logistic regression analysis were performed using SPSS.

RESULTS

Of 5961 participants, the non-CLBP group comprised 4098 women and the CLBP group comprised 1863. Adjusted logistic regression model revealed that dyslipidemia was positively associated with CLBP (odds ratio, 1.32; 95% confidence interval, 1.140, 1.530; p < 0.001). However, hypertension and diabetes were not associated with CLBP.

CONCLUSIONS

Our results suggest that proper treatment of dyslipidemia may contribute to lowering the risk of CLBP later in life.

Genetically predicted triglycerides mediate the relationship between type 2 diabetes Mellitus and intervertebral disc degeneration

BACKGROUND

To validate the causal relationship between type 2 diabetes mellitus (T2DM) and intervertebral disc degeneration (IVDD) and to identify and quantify the role of triglycerides (TGs) as potential mediators.

METHODS

A two-sample Mendelian randomization (MR) analyses of T2DM (61,714 cases and 1178 controls) and IVDD (20,001 cases and 164,682 controls) was performed using genome-wide association studies (GWAS). Moreover, two-step MR was employed to quantify the proportionate impact of TG-mediated T2DM on IVDD.

RESULTS

MR analysis showed that T2DM increased IVDD risk (OR: 1.0466, 95% CI 1.0049-1.0899, P = 0.0278). Reverse MR analyses demonstrated that IVDD does not affect T2DM risk (P = 0.1393). The proportion of T2DM mediated through TG was 11.4% (95% CI 5.5%-17.4%).

CONCLUSION

This work further validates the causality between T2DM and IVDD, with a part of the effect mediated by TG, but the greatest impacts of T2DM on IVDD remain unknown. Further studies are needed to identify other potential mediators.

Lipid metabolism disorder promotes the development of intervertebral disc degeneration

Lipid metabolism is a complex process that maintains the normal physiological function of the human body. The disorder of lipid metabolism has been implicated in various human diseases, such as cardiovascular diseases and bone diseases. Intervertebral disc degeneration (IDD), an age-related degenerative disease in the musculoskeletal system, is characterized by high morbidity, high treatment cost, and chronic recurrence. Lipid metabolism disorder may promote the pathogenesis of IDD, and the potential mechanisms are complex. Leptin, resistin, nicotinamide phosphoribosyltransferase (NAMPT), fatty acids, and cholesterol may promote the pathogenesis of IDD, while lipocalin, adiponectin, and progranulin (PGRN) exhibit protective activity against IDD development. Lipid metabolism disorder contributes to extracellular matrix (ECM) degradation, cell apoptosis, and cartilage calcification in the intervertebral discs (IVDs) by activating inflammatory responses, endoplasmic reticulum (ER) stress, and oxidative stress and inhibiting autophagy. Several lines of agents have been developed to target lipid metabolism disorder. Inhibition of lipid metabolism disorder may be an effective strategy for the therapeutic management of IDD. However, an in-depth understanding of the molecular mechanism of lipid metabolism disorder in promoting IDD development is still needed.

The impact of dyslipidemia on lumbar intervertebral disc degeneration and vertebral endplate modic changes: a cross-sectional study of 1035 citizens in China

BACKGROUND

Intervertebral disc degeneration (IDD) and vertebral endplate Modic changes (MCs) are common lumbar degenerative phenotypes related to low back pain (LBP). Dyslipidemia has been linked to LBP but its associations with IDD and MCs have not been fully elucidated. The present study aimed to address the possible link between dyslipidemia, IDD and MCs in the Chinese population.

METHODS

1035 citizens were enrolled in the study. The levels of serum total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C) and triglycerides (TG) were collected. IDD was evaluated based on the Pfirrmann grading system and subjects with an average grade ≥ 3 were defined as having degeneration. MCs were classified into typical types 1, 2 and 3. Covariables, including age, sex, BMI and fasting plasma glucose, were included for the adjustment of the logistic analyses.

RESULTS

The degeneration group included 446 subjects while the nondegeneration group included 589 subjects. The degeneration group had significant higher levels of TC and LDL-C (p < 0.001) whereas TG and HDL-C were not significantly different between the two groups. TC and LDL-C concentrations were significantly positively correlated with average IDD grades (p < 0.001). Multivariate logistic regression revealed that high TC (≥ 6.2 mmol/L, adjusted OR = 1.775, 95% CI = 1.209-2.606) and high LDL-C (≥ 4.1 mmol/L, adjusted OR = 1.818, 95% CI = 1.123-2.943) were independent risk factors for IDD. Type 1 MC presented in 84 (8.12%) subjects, type 2 MC presented in 244 (23.57%) subjects, type 3 MC presented in 27 (2.61%) subjects and no MC was observed in the remaining 680 (65.70%) subjects. The type 2 MC group demonstrated a higher level of TC, but the association between serum lipids and MCs could not be confirmed in further multivariate logistic regression.

CONCLUSIONS

High TC (≥ 6.2 mmol/L) and LDL-C (≥ 4.1 mmol/L) concentrations were independent risk factors for IDD for citizens in China. However, the association between dyslipidemia and MCs could not be determined. The effect of excess serum cholesterol may be critical for IDD and cholesterol lowering treatment may provide new opportunities in the management of lumbar disc degeneration.