Effect of a hypercholesterolemia as a starting factor on spinal degeneration in rabbits and role of Vitamin E (α-tocopherol)

Modic Changes in the Lumbar Spine: Exploring Their Association with Abdominal Aortic Calcification as a Potential Indicator of Systemic Atherosclerosis

BACKGROUND

This was a cross-sectional study on the correlation between abdominal aortic calcification (AAC) and Modic changes (MC). Little is known regarding the etiology of MC in the lumbar spine. Currently, insufficient vascularization of the endplate has been proposed to contribute to the appearance of MC. Our objective was to investigate whether AAC, a marker for a poor vascular status, is associated with MC in patients suffering from degenerative disc disease.

METHODS

Radiologic images of patients (n = 130) suffering from degenerative lumbar disc disease were reviewed. Type and severity of MC were assessed using magnetic resonance images, and severity of AAC was evaluated using computed tomography images or fluoroscopy. Both items were dichotomized into minimal and relevant grades. The correlation between them was studied using Spearman's correlation test, with age as a covariate.

RESULTS

Of the patients, 113 (87%) demonstrated MC (31% type I, 63% type II, and 6% type III) (55% relevant grade), and 68% had AAC (44% relevant grade). Spearman statistical analysis revealed that AAC was correlated with age (P < 0.001), whereas MC were not (P = 0.142). AAC severity was significantly correlated with MC, remaining so after age adjustment (P < 0.05). While MC type I lacked correlation with AAC, MC type II were significantly correlated with AAC (0.288, P = 0.015); however, this association lost significance after adjusting for age (P = 0.057).

CONCLUSIONS

AAC and MC (mainly MC type II) are associated, indicating that reduced blood supply or even a poor systemic vascularization status due to atherosclerotic disease may play a role in the formation of MC. Future studies focusing on the etiology of MC should pay more attention to patients' vascular status and determinants of abdominal aorta calcification.

Low-Density Lipoprotein Cholesterol and Statin Usage Are Associated With Rates of Pseudarthrosis Following Single-Level Posterior Lumbar Interbody Fusion

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

To investigate the relationships of low-density lipoprotein cholesterol and statin usage with pseudarthrosis following single-level posterior or transforaminal lumbar interbody fusion (PLIF/TLIF).

SUMMARY OF BACKGROUND DATA

Hypercholesterolemia can lead to atherosclerosis of the segmental arteries, which branch into vertebral bone through intervertebral foramina. According to the vascular hypothesis of disc disease, this can lead to ischemia of the lumbar discs and contribute to lumbar degenerative disease. Yet, little has been reported regarding the effects of cholesterol and statins on the outcomes of lumbar fusion surgery.

MATERIALS AND METHODS

TriNetX, a global federated research network, was retrospectively queried to identify 52,140 PLIF/TLIF patients between 2002 and 2021. Of these patients, 2137 had high cholesterol (≥130 mg/dL) and 906 had low cholesterol (≤55 mg/dL). Perioperatively, 18,275 patients used statins, while 33,415 patients did not. One-to-one propensity score matching for age, sex, race, and comorbidities was conducted to balance the analyzed cohorts. The incidence of pseudarthrosis was then assessed in the matched cohorts within the six-month, one-year, and two-year postoperative periods.

RESULTS

After propensity score matching, high-cholesterol patients had greater odds of developing pseudarthrosis six months [odds ratio (OR): 1.73, 95% confidence interval (CI): 1.28-2.33], one year (OR: 1.59, 95% confidence interval (CI): 1.20-2.10), and two years (OR: 1.57, 95% CI: 1.20-2.05) following a PLIF/TLIF procedure. Patients with statin usage had significantly lower odds of developing pseudarthrosis six months (OR: 0.74, 95% CI: 0.69-0.79), one year (OR: 0.76, 95% CI: 0.71-0.81), and two years (OR: 0.77, 95% CI: 0.72-0.81) following single-level PLIF/TLIF.

CONCLUSIONS

The findings suggest that patients with hypercholesterolemia have an increased risk of developing pseudarthrosis following PLIF/TLIF while statin use is associated with a decreased risk. The data presented may underscore an overlooked opportunity for perioperative optimization in lumbar fusion patients, warranting further investigation in this area.

Demographic and Clinical Characteristics of Patients With Cervical Spine Degeneration Reveal Frequent Cervicolumbar Tandem Spinal Stenosis in Mexico

BACKGROUND

Limited literature exists regarding the differences in demographics, causes, comorbidities, presentation, and structural changes associated with cervical spine degeneration in patients from distinct geographic regions. The authors aimed to evaluate the demographic and clinical characteristics of patients with cervical spine degeneration admitted to a single center in Mexico.

METHODS

This study enrolled patients with degenerative disease of the cervical spine. Clinical data were retrieved from medical records and retrospectively characterized.

RESULTS

A total of 50 patients with cervical spine degeneration were included in the analysis. Of these, 26% were men with a median age of 54 years. Hypertension, depression, anxiety, obesity, and alcohol consumption were presented in about a quarter of the participants. In addition, we observed hypertriglyceridemia and hypercholesterolemia in 72% and 46% of participants, respectively. The median duration of symptoms was 11 months, including radicular arm/neck pain (80%), tingling (80%), reduced muscle strength (48%), and gait disturbances (48%). Forty percent of patients had 2 cervical segments radiologically involved, mainly at C5-C6, with changes such as disc herniation (88%), foraminal stenosis with nerve root compression (67%), reduced spinal canal-to-vertebral body ratio (38%), and ligamentum flavum hypertrophy (24%). Also, 22% of patients showed degenerative cervical myelopathy. Strikingly, 48% of enrolled individuals showed cervicolumbar tandem spinal stenosis, mainly in L4-L5 and L5-S1, who were generally older, had a longer duration of symptoms, and had a higher comorbidity burden, including hyperglycemia, hypertension, and depression.

CONCLUSIONS

The demographic and clinical characteristics of degenerative cervical spine disease in Mexico differ with respect to other geographical regions by a younger age of diagnosis, a high frequency of cardiovascular, metabolic, and mental health comorbidities, and an increased prevalence of concomitant lumbar spinal stenosis.

CLINICAL RELEVANCE

Our findings reveal a considerably high burden of cervicolumbar tandem spinal stenosis as a distinctive feature of Mexican patients with cervical spine degeneration.

LEVEL OF EVIDENCE: 1

Nutrient metabolism of the nucleus pulposus: A literature review

Cells take in, consume, and synthesize nutrients for numerous physiological functions. This includes not only energy production but also macromolecule biosynthesis, which will further influence cellular signaling, redox homeostasis, and cell fate commitment. Therefore, alteration in cellular nutrient metabolism is associated with pathological conditions. Intervertebral discs, particularly the nucleus pulposus (NP), are avascular and exhibit unique metabolic preferences. Clinical and preclinical studies have indicated a correlation between intervertebral degeneration (IDD) and systemic metabolic diseases such as diabetes, obesity, and dyslipidemia. However, a lack of understanding of the nutrient metabolism of NP cells is masking the underlying mechanism. Indeed, although previous studies indicated that glucose metabolism is essential for NP cells, the downstream metabolic pathways remain unknown, and the potential role of other nutrients, like amino acids and lipids, is understudied. In this literature review, we summarize the current understanding of nutrient metabolism in NP cells and discuss other potential metabolic pathways by referring to a human NP transcriptomic dataset deposited to the Gene Expression Omnibus, which can provide us hints for future studies of nutrient metabolism in NP cells and novel therapies for IDD.