Lumbar stenosis and systemic diseases: is there any relevance?

The effect of diabetes mellitus on lumbar disc degeneration: an MRI-based study

PURPOSE

This study aims to analyse the effect of diabetes mellitus (DM) on the radiological changes of Magnetic Resonance Imaging (MRI) on the intervertebral discs and paravertebral muscle to investigate the effect of DM on spinal degeneration.

METHODS

This retrospective study initially included 262 patients who underwent treatment between January 2020 and December 2021 because of lumbar disc herniation. Amongst these patients, 98 patients suffered from type 2 diabetes mellitus (T2DM) for more than five years; this is the poorly controlled group (haemoglobin A1c (HbA1c) ≥ 6.5%; BMI: 26.28 ± 3.60; HbA1c: 7.5, IQR = 1.3). Another 164 patients without T2DM are included in the control group. The data collected and analysed include gender, age, smoking, alcohol use, disease course, Charlson Comorbidity Index, BMI, and radiological parameters including disc height, modified Pfirrmann grading scores, percentage of fat infiltration area of paravertebral muscle, and pathological changes of the endplate.

RESULTS

After propensity score-matched analysis, the difference in general data between the control and T2DM groups was eliminated, and 186 patients were analysed. The modified Pfirrmann grading scores showed statistical differences in every lumbar segment, suggesting that the T2DM group suffered from greater disc degeneration at all L1-S1 segments compared with the control group. The disc height from L1/2 to L5/S1 was not statistically different between the two groups. Compared to the T2DM group, the control group had a lower percentage of fat infiltration areas in L4/5 and L5/S1 paravertebral muscle, whereas L1/2 to L3/4 showed no statistical difference. The T2DM group had more pathological changes of cartilage endplate compared with the control group.

CONCLUSIONS

Prolonged uncontrolled hyperglycaemia may contribute to lumbar disc degeneration, fatty infiltration of the paraspinal muscles in the lower lumbar segments, and increased incidence of endplate cartilage pathological changes in patients with degenerative disc disease.

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.

The effectiveness of vitamin D3 supplementation in improving functional outcome of non-surgically treated symptomatic lumbar spinal stenosis: Randomized controlled clinical trial - Pilot study

BACKGROUND

Although vitamin D is one of the essential nutrients associated with musculoskeletal system function, there is no standard treatment method for vitamin D deficiency. This study aimed to investigate the effects of vitamin D supplementation on the improvement in symptoms, functional recovery of the spine, and changes in the quality of life in patients with spinal stenosis.

METHODS

In this prospective study, patients with spinal stenosis and serum 25-hydroxy vitamin D levels < 10 ng/mL were randomly assigned to a supplementation group (Group S) and a non-supplementation group (Group NS): 26 participants in Group S (16 females and 10 males) and 25 in Group NS (15 females and 10 males). The degree of lower back pain in both groups was assessed using the visual analog scale; spine function was assessed using the Oswestry disability index and Roland-Morris disability questionnaire; and patient quality of life was assessed using the 36-item short form health survey. We compared and analyzed the values that were measured at baseline, between 4 and 6 weeks (V1), 10 and 12 weeks (V2), and 22 and 26 weeks (V3).

RESULTS

No statistically significant difference was observed in lower back pain, spine function, or quality of life between both groups at baseline. In terms of lower back pain in V1, Group S scored 4.15 ± 3.12, while Group NS scored 5.64 ± 1.85 (P = .045). In V2, Group S scored 3.15 ± 2.38, while Group NS scored 4.52 ± 1.87 (P = .027). Moreover, in V3, Group S scored 3.58 ± 1.65, while Group NS scored 4.60 ± 1.68 (P = .033), indicating a statistically significant improvement in each period.

CONCLUSION

If a vitamin D deficiency that does not require surgical treatment exists in patients with lumbar spinal stenosis, high-dose vitamin D injections can improve lower back pain, which is the main symptom of lumbar spinal stenosis, as well as the functional outcomes of the spine and quality of life.

Japanese Orthopaedic Association (JOA) clinical practice guidelines on the management of lumbar spinal stenosis, 2021 - Secondary publication

BACKGROUND

The Japanese Orthopaedic Association (JOA) guideline for the management of lumbar spinal stenosis (LSS) was first published in 2011. Since then, the medical care system for LSS has changed and many new articles regarding the epidemiology and diagnostics of LSS, conservative treatments such as new pharmacotherapy and physical therapy, and surgical treatments including minimally invasive surgery have been published. In addition, various issues need to be examined, such as verification of patient-reported outcome measures, and the economic effect of revised medical management of patients with lumbar spinal disorders. Accordingly, in 2019 the JOA clinical guidelines committee decided to update the guideline and consequently established a formulation committee. The purpose of this study was to describe the formulation we implemented for the revision of the guideline, incorporating the recent advances of evidence-based medicine.

METHODS

The JOA LSS guideline formulation committee revised the previous guideline based on the method for preparing clinical guidelines in Japan proposed by the Medical Information Network Distribution Service in 2017. Background and clinical questions were determined followed by a literature search related to each question. Appropriate articles based on keywords were selected from all the searched literature. Using prepared structured abstracts, systematic reviews and meta-analyses were performed. The strength of evidence and recommendations for each clinical question was decided by the committee members.

RESULTS

Eight background and 15 clinical questions were determined. Answers and explanations were described for the background questions. For each clinical question, the strength of evidence and the recommendation were both decided, and an explanation was provided.

CONCLUSIONS

The 2021 clinical practice guideline for the management of LSS was completed according to the latest evidence-based medicine. We expect that this guideline will be useful for all medical providers as an index in daily medical care, as well as for patients with LSS.

Type 2 diabetes mellitus, physical activity, and neuromusculoskeletal complications

Objectives

The objectives of the study were to investigate the neuromusculoskeletal complications of Type 2 diabetes mellitus (T2DM) and their associated factors, including the level of physical activity (PA) and clinicodemographic characteristics.

Materials and Methods

In this cross-sectional analysis, we included 370 participants diagnosed with T2DM for no <1 year who satisfied the inclusion and exclusion criteria. Demographic and clinical characteristics were noted and a thorough clinical examination was performed on all the participants. International PA Questionnaire-Short Form was used to evaluate the level of PA of the participants. The continuous data is presented as mean ± SD and the categorical data is presented as the number of participants (n) and percentage (%). A logistic regression model was used to investigate the predictors for the prevalence of the complications.

Results

The mean duration of T2DM was 7.32 ± 5.53 years and the mean hemoglobin A1C (HbA1c) level (%) was 8.16±1.67. A majority of the participants were having uncontrolled diabetes with an HbA1c level ≥7.5% (n = 190; 51.35%). The level of PA was low in a substantial proportion of the participants (n = 276; 74.59%). A total of 162 (43.78%) participants were diagnosed with neuromusculoskeletal complications. Low back pain was the most common complication and degenerative disk disease was the most common diagnosis overall. Longer duration of diabetes, poor glycemic control, and low PA were associated with the prevalence of neuromusculoskeletal complications (P < 0.05).

Conclusion

Neuromusculoskeletal complications of T2DM are common and can result in significant disability in this population. Low PA is very common among T2DM patients and an important contributor to the development of complications. Health-care providers should consider PA an integral component of the management protocol for T2DM patients.

Impact of chronic hyperlipidemia on perioperative complications in patients undergoing lumbar fusion: a propensity score matching analysis

PURPOSE

Lumbar fusion is widely used to treat degenerative and traumatic conditions of the spine, with various perioperative complications. This study compared lumbar fusion complications in patients with and without chronic hyperlipidemia.

METHODS

Using the MSpine division of the PearlDiver database, patients with or without chronic hyperlipidemia who underwent lumbar fusions were identified. The appropriate Current Procedural Terminology (CPT) codes identified patients with single- or multi-level lumbar spinal fusion surgeries. International Classification of Diseases (ICD-9 and ICD-10) codes identified patients with chronic hyperlipidemia. The surgical and medical complications were obtained utilizing the appropriate ICD-9, ICD-10, and CPT codes. Propensity score matching analysis was used to control for confounding factors. Chi-square test was applied to compare the incidence of complications among different groups.

RESULTS

In single-level fusion group, patients with hyperlipidemia had a higher incidence of wound complications (P < 0.001), surgical site infection (P < 0.001), failed back syndrome (P < 0.001), hardware removal (P < 0.001), deep venous thrombosis/pulmonary embolism (P = 0.031), myocardial infarction (P < 0.001) cerebrovascular accident (P < 0.001), renal failure (P < 0.001), sepsis (P < 0.001), and urinary tract infection/incontinence (P < 0.001). In multi-level fusion group, patients with hyperlipidemia had a higher incidence of nerve root injury (P = 0.034), wound complications (P < 0.001), surgical site infection (P < 0.001), failed back syndrome (P < 0.001), hardware removal (P < 0.001), revision (P = 0.002), myocardial infarction (P < 0.001), renal failure (P < 0.001), and urinary tract infection/incontinence (P < 0.001).

CONCLUSION

Following lumbar fusion, patients with chronic hyperlipidemia have an increased risk of perioperative complications, including wound complications, surgical site infection, failed back surgery syndrome, hardware removal, myocardial infarction, renal failure, and urinary tract infection/incontinence.

Ligament Alteration in Diabetes Mellitus

Connective tissue ageing is accelerated by the progressive accumulation of advanced glycation end products (AGEs). The formation of AGEs is characteristic for diabetes mellitus (DM) progression and affects only specific proteins with relatively long half-lives. This is the case of fibrillar collagens that are highly susceptible to glycation. While collagen provides a framework for plenty of organs, the local homeostasis of specific tissues is indirectly affected by glycation. Among the many age- and diabetes-related morphological changes affecting human connective tissues, there is concurrently reduced healing capacity, flexibility, and quality among ligaments, tendons, bones, and skin. Although DM provokes a wide range of known clinical disorders, the exact mechanisms of connective tissue alteration are still being investigated. Most of them rely on animal models in order to conclude the patterns of damage. Further research and more well-designed large-cohort studies need to be conducted in order to answer the issue concerning the involvement of ligaments in diabetes-related complications. In the following manuscript, we present the results from experiments discovering specific molecules that are engaged in the degenerative process of connective tissue alteration. This review is intended to provide the report and sum up the investigations described in the literature concerning the topic of ligament alteration in DM, which, even though significantly decreasing the quality of life, do not play a major role in research.

Impact of lumbar spinal stenosis on metabolic syndrome incidence in community-dwelling adults in Aizu cohort study (LOHAS)

Metabolic syndrome and lumbar spinal stenosis (LSS) are common age-related diseases. However, the causal relationship between them remains unclear. This study aimed to identify the effects of LSS on metabolic syndrome incidence in community-dwelling adults. This prospective cohort study included participants of the Aizu cohort study (LOHAS) aged < 75 years as of 2008. Participants with metabolic syndrome at baseline were excluded. The primary outcome measure was metabolic syndrome incidence, and the main explanatory variable was the presence of LSS, as assessed by a self-reported questionnaire. A multivariate Cox proportional hazard regression model was used to estimate hazard ratios (HRs) for metabolic syndrome incidence during the 6-year follow-up period. Complete-case analyses were compared with the multiple imputation results. Among 1599 participants, 1390 complete cases were analyzed (mean [SD] age 62.3 [9.0] years; females, 734 [52.8%]). Among those participants, 525 (37.8%) developed metabolic syndrome during the follow-up of 3.89 [1.96] years. The presence of LSS was associated with developing metabolic syndrome (HR, 1.41; 95% confidence interval [CI] 1.02–1.95). Multiple imputation results showed similar trends of those having complete-case data (HR, 1.47; 95% CI 1.08–2.00). This finding suggests the importance of prevention and management of LSS in community settings.

Diabetes Mellitus-A Risk Factor for the Development of Lumbar Disc Degeneration: A Retrospective Study of an Indian Population

STUDY DESIGN

A retrospective study.

OBJECTIVES

To determine the association between type-2 diabetes mellitus (T2DM) and the severity of lumbar disc degeneration disease (LDDD).

METHODS

We included 199 patients with low back pain (LBP) who visited our hospital from 2016 to 2018. All patients were divided into 3 groups as per inclusion criteria. Group A, patients without DM (n = 75); group B, patients with controlled DM (n = 72); and group C, patients with uncontrolled DM (n = 52). The patients were further subdivided into group B1, DM duration ≤10 years (n = 38); group B2, DM duration >10 years (n = 34); group C1 DM duration ≤10 years (n = 28); and group C2, DM duration >10 years (n = 24). Sex, age, body mass index, occupation, smoking history, alcohol use, and duration of T2DM were recorded. The severity of LDDD was evaluated using the 5-level Pfirrmann grading system. Operated patients' disc materials were sent for histological examination.

RESULTS

Demographic data showed no difference among groups (P > 0.5), except age. Patients with DM showed more severe disc degeneration compared with patients without DM. The average Pfirrmann scores between groups A and B1 had no difference; groups B2, C1, and C2 showed higher average Pfirrmann scores than group A (P < 0.05). Groups B2 and C2 showed higher average Pfirrmann scores than groups B1 and C1 (P < 0.05). Groups C1 and C2 showed higher average Pfirrmann scores than groups B1 and B2 (P < 0.05). The severity of LDDD was significantly related to DM duration in both groups B and C (P < 0.05). DM groups showed increased disc apoptosis and matrix aggrecan fragmentation, disc glycosaminoglycan content and histological analysis were significantly different; the results are similar to Pfirrmann score results.

CONCLUSIONS

DM duration >10 years and uncontrolled DM were risk factors for LDDD.

Association of Lumbar Spinal Stenosis with Severe Disability and Mortality Among Community-Dwelling Older Adults: The Locomotive Syndrome and Health Outcomes in the Aizu Cohort Study

STUDY DESIGN

This prospective cohort study analyzed data from the Locomotive Syndrome and Health Outcomes in the Aizu Cohort Study.

OBJECTIVE

To investigate the association between lumbar spinal stenosis (LSS) and severe disability and mortality among community-dwelling older adults.

SUMMARY OF BACKGROUND DATA

Only a few studies have investigated LSS longitudinally, and the study participants were limited to selected patients diagnosed with LSS during a hospital visit. Additionally, the prognosis of LSS remains unclear.

METHODS

We enrolled independent community-dwelling older adults aged 65 years or older at the time of a baseline health checkup in 2008. LSS was diagnosed using a validated diagnostic support tool for LSS. The primary endpoint was a composite of severe disability (long-term care insurance certification grade 4 or 5) and mortality. We used 1 minus Kaplan-Meier failure estimates and the log-rank test to compare the interval between baseline and the predetermined endpoint as well as a Cox proportional hazards model to estimate hazard ratios (HRs) for the LSS group with adjustment for possible confounders. Multiple imputation by chained equations was performed for sensitivity analysis.

RESULTS

Of 2058 subjects enrolled, 1560 did not have missing covariates; 269 (17%) were diagnosed with LSS. After a median follow-up of 5.8 years, the rates of severe disability and mortality were 0.022 per year in subjects with LSS and 0.012 per year in those without (P = 0.006). The adjusted HR for the composite endpoint in the LSS group was 1.55 (95% confidence interval [CI], 1.01-2.38). A similar association was observed after multiple imputation of missing covariates (adjusted HR, 1.51 [95% CI, 1.06-2.16]).

CONCLUSION

LSS was associated with severe disability and mortality in community-dwelling older adults. Detection of adults with LSS in the community may contribute to local health promotion.Level of Evidence: 2.

Functional Recovery after Surgery for Lumbar Spinal Stenosis in Patients with Hypertension

Hypertension is a prevalent condition that is associated with lower health status in patients with lumbar spinal stenosis. The study determined whether hypertension is a prognostic factor associated with functional recovery after spine surgery for lumbar spinal stenosis. This was a secondary analysis of the Alberta Lumbar Spinal Stenosis Study in which patients were identified as participants at the time of lumbosacral magnetic resonance imaging or computed tomography in Calgary, Alberta, Canada. Multivariable linear regression analyses were performed to examine hypertension as a prognostic factor of functional recovery after surgery (Oswestry Disability Index, the Swiss Spinal Stenosis (SSS)-Symptom Severity and SSS-Physical Function scales). Of the 97 surgical participants, 49 who were hypertensive were older (76.8, SD 11.4 years) than the 48 non-hypertensive participants (66.7, SD 12.4 years) (p < 0.001). No significant associations between hypertension and post-operative function in any of the three multivariable models were seen. The Oswestry Disability Index mean score improved after surgery (effect size: 1.73; 95%CI: 1.39, 2.06), with no differences seen between those with and without hypertension (p = 0.699). Large changes were seen after surgery for the SSS-Symptom Severity (effect size: 1.0, 95%CI 0.7, 1.3) and SSS-Physical Function (effect size: 0.9, 95%CI 0.6, 1.2) scales. Hypertension alone does not negatively impact functional recovery following surgery.

Lumbar Spinal Canal Stenosis from the Perspective of Locomotive Syndrome and Metabolic Syndrome: A Narrative Review

Patients with lumbar spinal canal stenosis (LSS) have impaired activities of daily living because of pain or motor paralysis, but no effective preventive treatment is currently available. The number of patients with LSS is predicted to continually increase as the average age of the global population increases. To provide a conceptual framework for improving healthy life expectancy, the Japanese Orthopaedic Association introduced the concept of locomotive syndrome, to which LSS is related. Ours and other studies have shown that LSS exacerbates locomotive syndrome and that surgical treatment is one method for improving it. Furthermore, we propose that the two-step test, a locomotive syndrome risk test, is effective for assessing the risk for falls and severity of LSS. Meanwhile, lumbar spinal epidural lipomatosis (LSEL), which is a manifestation of LSS, has been shown to be related to metabolic syndrome. Previous studies have suggested that the whole LSS can be also associated with metabolic syndrome. Although locomotive syndrome is very different from metabolic syndrome, which involves lipid metabolism, these two syndromes overlap, such as in LSS. Conducting research on LSS from the perspectives of both locomotive syndrome and metabolic syndrome may lead to novel methods for prevention and treatment of LSS and, conversely, may yield clues for resolving symptoms of the two syndromes. This review provides an overview of LSS from the perspective of locomotive syndrome and metabolic syndrome, along with findings from our research group.

Effects of type 1 diabetes mellitus on lumbar disc degeneration: a retrospective study of 118 patients

BACKGROUND

The study aimed to investigate the correlation between type 1 diabetes (T1D) and lumbar disc degeneration (LDD).

METHODS

A retrospective analysis of 118 patients with T1D recruited from January 2014 to March 2019 was performed, and multivariate logistic regression was used to analyse the incidence of T1D; the age, sex, and body mass index (BMI) of the patients; the disease duration and the glycosylated haemoglobin and venous blood glucose levels. All patients who suffered low back pain were assessed by MRI using the Pfirrmann grading system.

RESULTS

A total of 118 patients with an average age of 36.99 ± 17.01 (8-85 years) were reviewed. The mean hospitalization duration, venous glucose fluctuation range, glycated haemoglobin level, highest venous glucose level, venous glucose level, and disease course duration were 13.98 ± 10.16 days, 14.99 ± 5.87 mmol/L, 9.85 ± 2.52 mmol/L, 25.29 ± 7.92 mmol/L, 13.03 ± 5.75 mmol/L and 7.30 ± 8.41 years. The average Pfirrmann scores of the different discs were 2.20 ± 0.62 (L1-2), 2.35 ± 0.67 (L2-3), 2.90 ± 0.45 (L3-4), 4.20 ± 0.52 (L4-5) and 4.10 ± 0.72 (L5-S1). The patients with T1D showed severe disc degeneration. The male sex, glycosylated haemoglobin, venous glucose and venous glucose fluctuations were significantly associated with LDD (P < 0.05).

CONCLUSIONS

Glycosylated haemoglobin, the male, venous glucose and the venous glucose fluctuation range were risk factors for LDD.

A Review of Vitamin D in Spinal Surgery: Deficiency Screening, Treatment, and Outcomes

In this review, we discuss the demonstrated value of vitamin D in bone maintenance, fracture resistance, spinal health, and spine surgery outcomes. Despite this, the effect of vitamin D levels in spine surgery has not been well described. Through this review of literature, several conclusions were drawn. First, despite the fact that a high number of spine surgery patients are vitamin D deficient, screening is not commonly performed. Second, adequate vitamin D levels will not be achieved in a majority of these patients without supplementation. Last, inadequate vitamin D levels may increase the risk of pseudarthrosis. Given these findings, we suggest that many patients undergoing spinal surgery could be treated with vitamin D supplementation prior to surgery without the need for confirmatory testing for vitamin D deficiency. This is a more cost-effective method than screening all patients. However, future randomized trials and cost-effectiveness analyses are needed to determine the ultimate effects of vitamin D supplementation on clinical morbidity and surgical outcomes.

Ligamentum flavum fibrosis and hypertrophy: Molecular pathways, cellular mechanisms, and future directions

Hypertrophy of ligamentum flavum (LF), along with disk protrusion and facet joints degeneration, is associated with the development of lumbar spinal canal stenosis (LSCS). Of note, LF hypertrophy is deemed as an important cause of LSCS. Histologically, fibrosis is proved to be the main pathology of LF hypertrophy. Despite the numerous studies explored the mechanisms of LF fibrosis at the molecular and cellular levels, the exact mechanism remains unknown. It is suggested that pathophysiologic stimuli such as mechanical stress, aging, obesity, and some diseases are the causative factors. Then, many cytokines and growth factors secreted by LF cells and its surrounding tissues play different roles in activating the fibrotic response. Here, we summarize the current status of detailed knowledge available regarding the causative factors, pathology, molecular and cellular mechanisms implicated in LF fibrosis and hypertrophy, also focusing on the possible avenues for anti-fibrotic strategies.

Changes in Blood Glucose Level After Steroid Injection for Musculoskeletal Pain in Patients With Diabetes

Objective

To investigate changes in blood glucose level after steroid injection in patients with type 2 diabetes mellitus (DM) and factors affecting those changes.

Methods

We retrospectively studied 51 patients with type 2 DM who underwent steroid injection for shoulder and back pain. Mean fasting blood sugar (FBS) levels for 7 days before steroid injection was used as the baseline blood glucose level, which was compared with FBS levels for 14 days after steroid injection. We compared the differences in blood glucose changes between HbA1c >7% and HbA1c ≤7% groups and those between insulin and non-insulin treated groups. Demographic data, injection site, and steroid dose were analyzed.

Results

Compared to baseline, blood glucose significantly (p=0.012) elevated 1 day after steroid injection but not 2 days after injection. In the HbA1c >7% and insulin groups, blood glucose was significantly increased 1 day after injection compared to that in the HbA1c ≤7% (p=0.011) and non-insulin (p=0.024) groups, respectively. Higher HbA1c level before injection was significantly (p=0.003) associated with the degree of blood glucose increase 1 day after injection. No significant differences were noted in the degree of blood glucose increase according to injection site or steroid dose.

Conclusion

Higher HbA1c level was associated with greater elevation in blood glucose 1 day after steroid injection. Careful monitoring of blood glucose is required on the first day after steroid injection in patients with poorly controlled DM.

High glucose promotes annulus fibrosus cell apoptosis through activating the JNK and p38 MAPK pathways

Diabetes mellitus (DM) is an important risk factor of intervertebral disc degeneration. A high glucose niche-mediated disc cell apoptosis is an implicate causative factor for the spine degenerative diseases related with DM. However, the effects of a high glucose niche on disc annulus fibrosus (AF) cell apoptosis and the potential signaling transduction pathway is unclear. The present study is to investigate the effects of high glucose on disc AF cell apoptosis and the role of two potential signaling pathways in this process. Rat AF cells were cultured in baseline medium or medium with different concentrations (0.1 and 0.2 M) of glucose for 3 days. Flow cytometry was used to assess the degree of apoptosis. Activity of caspase 3/9 was evaluated by chemical kit. Expression of pro-apoptotic and anti-apoptotic molecules was analyzed by real-time polymerase chain reaction and Western blot. In addition, activity of the C-Jun NH₂-terminal kinases (JNK) pathway and p38 mitogen-activated protein kinase (MAPK) pathway was evaluated by Western blot. Compared with the control group, high glucose culture increased cell apoptosis ratio and caspase-3/9 activity, up-regulated expression of bax, caspase-3, cleaved caspase-3 and cleaved PARP, and down-regulated expression of bcl-2 in a glucose concentration-dependent manner. Additionally, high glucose culture increased expression of the p-JNK and p-p38 MAPK in a concentration-dependent manner. Further results showed that inhibition of the JNK or p38 MAPK pathway attenuated the effects of high glucose on AF cell apoptosis. Together, high glucose promoted disc AF cell apoptosis through regulating the JNK pathway and p38 MAPK pathway in a glucose concentration-dependent manner.

Influence of diabetes mellitus on patients with lumbar spinal stenosis: A nationwide population-based study

Purpose

To evaluate the relationship between comorbidities, medical cost, and surgical outcome in patients with lumbar spinal stenosis (LSS) and diabetes mellitus (DM).

Methods

Data on patients with LSS (n = 14,298) were collected from the Korean National Health Insurance Service database from 2005 to 2007. After 8 years of follow-up, a “DM group” (n = 3,478) and a “non-DM group” (n = 10,820) were compared according to outcome measures. Cox proportional hazard regressions were performed to examine the relationship between DM, hypertension (HTN), cardiovascular disease (CVD), chronic kidney disease (CKD), cerebrovascular disease (CbVD), and surgery for LSS. The admission rate and medical cost as well asthe overall survival rate for those who underwent lumbar surgery were also assessed among patients with DM and LSS.

Results

Mortality was about 1.35 times higher in the DM group than in the non-DM group. Patients with DM and comorbidities including HTN (hazard ratio [HR], 1.40; 95% confidence interval [CI], 1.25–1.56; p<0.001), CVD (HR, 1.53; 95% CI, 1.36–1.73; p<0.001), CKD (HR, 3.18; 95% CI, 2.7–3.76; p<0.001), and CbVD (HR, 1.69; 95% CI, 1.49–1.91; p<0.001) showed an increased risk of mortality. The mean hospitalization time and average medical cost of patients with DM who underwent lumbar surgery were 60.8 days, and 7,127 USD, respectively. This was 31.3 days longer, and 6,207 USD higher, respectively, than those of patients with DM who underwent conservative treatment for LSS. Within the DM group, the survival rate of surgical management of LSS had a significant tendency for positive prognosis compared with those administered conservative treatment (p = 0.046).

Conclusions

In patients with LSS, DM was associated both with poor prognosis (most significantly in those with CKD), and increased medical cost in those who underwent surgery. Nevertheless, surgical treatment for LSS in patients with DM was related to favorable prognosis compared with conservative treatment.

High glucose-induced excessive reactive oxygen species promote apoptosis through mitochondrial damage in rat cartilage endplate cells

Diabetes mellitus (DM) is an important factor in intervertebral disc degeneration (IDD). Apoptosis of cartilage endplate (CEP) cells is one of the initiators of IDD. However, the effects of high glucose on CEP cells are still unknown. Therefore, we conducted the present study to evaluate the effects of high glucose on CEP cells and to identify the mechanisms of those effects. Rat CEP cells were isolated and cultured in 10% foetal bovine serum (FBS, normal control) or high-glucose medium (10% FBS + 0.1 M glucose or 10% FBS + 0.2 M glucose, experimental conditions) for 1 or 3 days. In addition, CEP cells were treated with 0.2 M glucose for 3 days in the presence or absence of alpha-lipoic acid (ALA, 0.15 M). Flow cytometry was performed to identify and quantify the degree of apoptosis. The expression of reactive oxygen species (ROS) was assessed by flow cytometry, and mitochondrial damage (mitochondrial membrane potential) was assessed by fluorescence microscopy. Furthermore, the expression levels of cleaved caspase-3, cleaved caspase-9, Bcl-2, Bax, and cytochrome c were evaluated by Western blotting. High glucose significantly increased apoptosis and ROS accumulation in CEP cells in a dose- and time-dependent manner. Meanwhile, a disrupted mitochondrial membrane potential was detected in rat CEP cells cultured in the two high glucose concentrations. Incubating in high glucose enhanced the expression levels of cleaved caspase-3, cleaved caspase-9, Bax, and cytochrome c but decreased the level of the anti-apoptotic protein Bcl-2. ALA inhibited the expression of cleaved caspase-3, cleaved caspase-9, Bax, and cytochrome c but enhanced the expression of Bcl-2. ALA also prevented disruption of the mitochondrial membrane potential in CEP cells. This study demonstrates that high glucose-induced excessive reactive oxygen species promote mitochondrial damage, thus causing apoptosis in rat CEP cells in a dose- and time-dependent manner. ALA could prevent mitochondrial damage and apoptosis caused by high glucose in CEP cells. The results suggest that appropriate blood glucose control may be the key to preventing IDD in diabetic patients. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:2476-2483, 2018.

Factors associated with lumbar spinal stenosis in a large-scale, population-based cohort: The Wakayama Spine Study

Objective

Patients with lumbar spinal stenosis (LSS) who have radiographically similar degrees of stenosis may not necessarily exhibit equivalent symptoms. As part of a cross-sectional study, we examined factors associated with symptomatic LSS (sLSS) in the general population of Japan.

Methods

We evaluated 968 participants (men, 319; women, 649) between 2008 and 2010. Orthopedic surgery specialists diagnosed sLSS using interview results, medical examinations, and imaging findings. LSS was radiographically graded using a 4-level scale. Additionally, we examined basic anthropometry, smoking habits, alcohol consumption, ankle-brachial index values (ABI), and glycosylated hemoglobin (HbA1c) levels. We grouped patients with moderate and severe radiographic LSS, and compared the indicated factors on the basis of the presence/absence of sLSS. Data were evaluated using multiple logistic regression analyses.

Results

Radiographically, 451 participants had moderate and 288 severe stenosis. Clinically, 92 participants were diagnosed with sLSS, including 36 with moderate and 52 with severe stenosis. In the moderate stenosis group, participants with sLSS had significantly higher rates of diabetes mellitus (DM) and lower ABIs than did non-LSS participants. Although sLSS participants tended to be older (p = 0.19), there were no significant differences in the sex distribution, body mass index values, or in the percentages of participants who were drinkers/smokers. In the severe stenosis group, there were no differences in any of the evaluated factors. Multiple logistic regression showed that DM (odds ratio [OR], 3.92; 95% confidence interval [CI], 1.52–9.34]) and low ABI (1 SD = 0.09; OR, 1.36; 95% CI, 1.04–1.81) were significantly associated with LSS in the moderate stenosis group.

Conclusions

DM and low ABIs are significantly associated with sLSS in patients with moderate radiographic stenosis. Neither factor is associated with sLSS in patients with severe stenosis. Notably, the effects of intrinsic factors on symptomology may be masked when anatomic stenosis is severe.

The Difference in Gender Affects the Pathogenesis of Ligamentum Flavum Hypertrophy

Introduction

Gender differences may play a role in the pathogenesis of lumbar spinal stenosis. However, few reports that discuss the effects of gender differences in ligamentum flavum (LF) hypertrophy have been published, and no study has investigated the relationship between LF thickness and the quantitative value of intervertebral disc (IVD) degeneration. This study aimed to investigate the impact of gender on the pathomechanisms underlying LF hypertrophy, focusing on the relationship among LF thickness, IVD degeneration, and age.

Methods

The subjects include 100 patients with low back pain and leg numbness, tingling, or pain. We measured LF thickness and the T2 values of IVDs using MR imaging and analyzed the relationship among LF thickness, T2 values of IVDs, and age. The interclass correlation coefficient (ICC) was calculated as the inter-rater reliability between the LF thickness values measured by two investigators.

Results

ICC was calculated for the two measurements of LF thickness (r = 0.923, 95% CI: 0.907-0.936). No statistically significant difference in the T2 values of IVDs was observed between females and males from L2/3 to L5/S. There were significantly negative linear correlations between LF thickness and the T2 values of IVDs at all levels, but this correlation was not observed in females at L4/5. There were significantly negative linear correlations between age and the T2 values of IVDs from L2/3 to L5/S for all patients, females, and males (r = 0.422-0.756). In addition, there were significantly positive linear correlations between age and LF thickness from L2/3 to L4/5 for all patients (r = 0.329-0.361) and females (r = 0.411-0.481). Correlations were not observed for males at all levels or for all patients at L5/S.

Conclusions

The relationships identified among LF thickness, age, and IVD degeneration suggest that gender differences play a role in the pathogenesis of LF hypertrophy.

The potential effect of type 2 diabetes mellitus on lumbar disc degeneration: a retrospective single-center study

Background

Diabetes mellitus (DM) and low back pain which is mainly caused by degeneration of the intervertebral discs (IVDs) both are major public health problem worldwide. The present study was designed to investigate the association between type 2 diabetes mellitus (T2D) and severity of lumbar disc degeneration (LDD).

Methods

We retrospectively reviewed patients with low back pain visiting our spine clinic in 2014. Low back pain patients all have the lumbar MRI imaging and no previous treatment. One hundred fifty patients without T2D (group A) and 622 patients with T2D meeting the criteria were included. Sex, age, body mass index (BMI), high blood pressure (HBP), history of smoking, alcohol use, and duration of T2D were recorded. Patients with T2D were assigned to a well-controlled group (group B, n = 380) and a bad-controlled group (group C, n = 242). In group B, T2D duration of 148 patients was ≤ 10 years (group B1) and 232 patients > 10 years (group B2). In group C, T2D duration of 100 patients was ≤ 10 years (group C1) and 142 patients > 10 years (group C2). The severity of LDD was evaluated using the five-level Pfirrmann grading system. Data were analyzed using SPSS 19.0.

Results

Demographic data except age showed no difference among groups (P > 0.5). Compared to patients without T2D, patients with T2D showed more severe disc degeneration after removal of age effects (P < 0.05). From L1/2 to L5/S1, the average Pfirrmann scores between groups A and B1 showed no difference(P > 0.05); groups B2, C1, and C2 showed higher average Pfirrmann scores than group A (P < 0.05). Groups B2 and C2 showed higher average Pfirrmann scores than groups B1 and C1 (P < 0.05). Groups C1 and C2 showed higher average Pfirrmann scores than groups B1 and B2 (P < 0.05). From L1/2 to L5/S1, the severity of LDD was highly positively related to T2D duration both in groups B and C (P < 0.05).

Conclusions

T2D duration > 10 years and a bad control of T2D were risk factors for LDD. The longer T2D duration was, the more severe disc degeneration would be.

Diabetes mellitus is associated with increased elastin fiber loss in ligamentum flavum of patients with lumbar spinal canal stenosis: results of a pilot histological study

PURPOSE

Lumbar spinal canal stenosis (LSCS) is associated with fibrosis, decreased elastin-to-collagen ratio, and hypertrophy of the ligamentum flavum (LF). Diabetes mellitus (DM) is known to cause metabolic disturbances within the extracellular matrix in multiple tissues. These alterations may play a major role in the severity of clinical symptoms of LSCS affecting diabetic patients. We aimed to examine the hypothesis that DM may contribute to the LF changes seen in patients with LSCS.

METHODS

The study cohort included 29 patients: 23 with LSCS (10 with DM vs. 13 without DM) as well as six patients with lumbar disc herniation (LDH). Surgical LF specimens were retrieved for histological assessment. Morphologic quantification of confocal microscopy images using fast Fourier transform analysis allowed us to compare anisotropy and elastin fiber orientation between groups.

RESULTS

There was a significant positive correlation between fasting plasma glucose values and degree of elastin degradation (r = 0.36, p = 0.043). The diabetic patients with LSCS showed a significantly greater loss of elastic fibers (2.3 ± 0.9 vs. 1.5 ± 0.55, p = 0.009), although fibrosis was shown to be similar (1.44 ± 0.7 vs. 1.43 ± 0.88, p = 0.98). There was no significant difference in the degree of calcification in the LSCS group between patients with and without diabetes (1.71 vs. 2.05%, p = 0.653). Fiber orientation was found to be less homogenous in the LSCS compared with the LDH group, although not significantly affected by DM.

CONCLUSIONS

The present study points to a significant contribution of DM to the loss of elastin fibers that occurs in the LF of patients with LSCS.

Diabetes and Back Pain: Markers of Diabetes Disease Progression Are Associated With Chronic Back Pain

IN BRIEF Diabetes has been associated with the incidence of back pain. However, the relationship between markers of diabetes progression and back pain has not been studied. The objective of this study was to correlate clinical and laboratory measures of diabetes disease severity to the presence of back pain to provide insight into the relationship between these conditions. Findings showed that markers of diabetes disease progression were associated with the presence of back pain, suggesting that uncontrolled diabetes may contribute to the development of chronic back pain.

Increased sorbitol levels in the hypertrophic ligamentum flavum of diabetic patients with lumbar spinal canal stenosis

The pathomechanism of the ligamentum flavum (LF) hypertrophy in diabetic patients with lumbar spinal canal stenosis (LSCS) remains unclear. A cross-sectional study was undertaken to investigate the mechanism of LF hypertrophy in these patients. Twenty-four diabetic and 20 normoglycemic patients with LSCS were enrolled in the study. The structure of the LF in the study subjects was evaluated using histological and immunohistochemical methods, and the levels of sorbitol, pro-inflammatory cytokines, and the fibrogenic factor, TGF-β1, in the LF were analyzed. In vitro experiments were performed using NIH3T3 fibroblasts to evaluate the effect of high-glucose conditions and an aldose reductase inhibitor on the cellular production of sorbitol, pro-inflammatory factors, and TGF-β1. We found that the LF of diabetic patients exhibited significantly higher levels of sorbitol and pro-inflammatory cytokines, TGF-β1 and of CD68-positive staining than that of the normoglycemic subjects. The diabetic LF was significantly thicker than that of the controls, and showed evidence of degeneration. The high glucose-cultured fibroblasts exhibited significantly higher levels of sorbitol, pro-inflammatory factors, and TGF-β1 compared to the low glucose-cultured cells, and these levels were dose-dependently reduced by treatment with the aldose reductase inhibitor. Taken together, our data suggests that increased sorbitol levels in the LF of diabetic patients results in increased production of pro-inflammatory and fibrogenic factor, which contribute to LF hypertrophy, and could increase the susceptibility of diabetic patients to LSCS. Furthermore, aldose reductase inhibition effectively reduced the levels of sorbitol and sorbitol-induced pro-inflammatory factor expression in high glucose-cultured fibroblasts. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1058-1066, 2017.

Changes in HbA1c levels and body mass index after successful decompression surgery in patients with type 2 diabetes mellitus and lumbar spinal stenosis: results of a 2-year follow-up study

BACKGROUND CONTEXT

Lumbar spinal stenosis (LSS) can hinder a patient's physical activity, which in turn can impair glucose tolerance and body weight regulation in patients with type 2 diabetes mellitus (DM-2). Therefore, successful lumbar surgery could facilitate glycemic control and body weight regulation.

PURPOSE

This study aimed to evaluate the effects of postoperative improvement in physical activity on body mass index (BMI) and hemoglobin A_1c (HbA_1c) level in patients with LSS and DM-2 over a 2-year follow-up period.

STUDY DESIGN

Prospective longitudinal observational study.

PATIENT SAMPLE

Patients with LSS and DM-2.

OUTCOME MEASURES

Visual analogue scale (VAS) scores for back pain and leg pain, Oswestry Disability Index (ODI) scores, Japanese Orthopaedic Association (JOA) scores, JOA Back Pain Evaluation Questionnaire (JOABPEQ) sections, BMI, and blood analysis for HbA_1c were carried out.

METHODS

A total of 119 patients were enrolled for analysis of the effect of successful decompression surgery on changes in HbA_1c levels and BMI. The VAS score, ODI score, JOA score, JOABPEQ, BMI, HbA_1c were reassessed at 6 months, 1 year, and 2 years after surgery. Additionally, correlations between changes in HbA_1c and changes in the ODI, JOA, JOABPEQs, and BMI were analyzed.

RESULTS

The overall values of HbA1c before and at 6 months, 1 year, and 2 years after the surgery were 7.08±0.94%, 6.58±0.87%, 6.59±0.79%, and 6.59±0.79%, respectively (p-values; 6 months: .024; 1 year: .021; 2 years: .038). In the not well-controlled sugar (non-WCS) group (preoperative HbA_1c>6.5%), the difference between pre- and postoperative HbA_1c was highly statistically significant (p<.01). The overweight group (preoperative BMI≥25) showed statistically significant BMI reduction in the second year after surgery (p=.034). The postoperative HbA_1c changes are strongly correlated with the improvements of ODI, JOA, and JOABPEQ after surgery.

CONCLUSIONS

The present study demonstrates that in patients with DM-2 and LSS, successful lumbar surgery may facilitate glycemic control by enabling an increase in the patient's level of physical activity. Additionally, it could help reduce body weight in overweight (BMI>25) patients with DM-2 and LSS.

T2 relaxation time for intervertebral disc degeneration in patients with upper back pain: initial results on the clinical use of 3.0 Tesla MRI

Background

Magnetic resonance imaging (MRI) is a useful non-invasive tool for evaluating abnormalities of intervertebral discs. However, there are few studies which applied functional MRI techniques to investigate degenerative changes in cervical and cervicothoracic junction (CTJ) spine among adults. The aim of this study was to compare T2 relaxation time measurement evaluation with morphological grading for assessing cervical and CTJ intervertebral discs (IVD) in the patients suffering neck, shoulder, and upper back pain.

Methods

Sixty-three patients (378 IVDs) and 60 asymptomatic volunteers (360 IVDs) of the cervical and CTJ discs were assessed using a 3.0 T magnetic resonance imaging (MRI) protocol, including an sagittal T2 relaxation time protocol. The relaxation time values of the nucleus pulposus (NP) were recorded and all discs were visually graded according to Pfirrman’s grading system. The correlation between T2 relaxation time values and qualitative clinical grading of degeneration, patient age, sex and anatomic level were analyzed

Results

There is a clear trend of decreasing mean T2 values of the NP associate with increasing Pfirrmann grades (C2-T1) for both patients and asymptotic volunteers. Significant T2 differences were seen among grades I-V (P < 0.05). However, grade V was not observed in the CTJ. Linear correlation analysis revealed a strong negative association between T2 values of the NP and Pfirrmann grade (r = −0.588, r = −0.808) of C2-7 and C7T1. Age were also significantly correlated NP T2 values (r = −0.525, r = −0.723) for patients and volunteers. Moreover, the receiver operating characteristic analysis for average measures in a range from 0.70-0.79 (C2-7) to 0.84-0.89 (C7T1) for patients.

Conclusions

T2 quantitation provides a more sensitive and robust approach for detecting and characterizing the early stage of IVD degeneration and age-associated disc changes.

Electronic supplementary material

The online version of this article (doi:10.1186/s12880-017-0182-z) contains supplementary material, which is available to authorized users.

Expression of adiponectin receptors in human and rat intervertebral disc cells and changes in receptor expression during disc degeneration using a rat tail temporary static compression model

BACKGROUND

Adipose tissue is a large endocrine organ known to secret adiponectin, which has anti-diabetic, anti-atherogenic, and anti-inflammatory properties. Adiponectin is widely involved in systemic disease, diabetes mellitus, and cardiac infraction. This study aimed to investigate the involvement of adiponectin in intervertebral disc (IVD) degeneration.

METHODS

Adipose and IVD tissues were obtained from human patients undergoing surgery (n = 4) and from skeletally mature Sprague-Dawley rats (n = 21). Tissues were stained immunohistochemically for adiponectin and adiponectin receptors AdipoR1 and AdipoR2. Changes in adiponectin receptor expression with IVD degeneration severity were then investigated using a rat tail temporary compression model. Rat IVD tissues were stained immunohistochemically with AdipoR1 or AdipoR2, and immunopositive cell percentages were calculated. Rat nucleus pulposus (NP) and annulus fibrosus (AF) tissues were isolated separately and treated with recombinant adiponectin (Ad 0.1 or 1.0 μg/ml) and/or interleukin-1 beta (IL-1β) (0.2 μg/ml) for 24 h. The four groups were as follows: control group (no treatment), IL-1β group (IL-1β-only treatment), IL-1β+Ad (0.1) group (IL-1β and adiponectin [0.1 μg/ml] treatment), and IL-1β+Ad (1.0) group (IL-1β and adiponectin [1.0 μg/ml]). Real-time reverse transcription-polymerase chain reaction was performed to evaluate messenger-RNA (mRNA) expression of tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6).

RESULTS

Adiponectin was widely expressed in human subcutaneous and epidural adipose tissue. In rat IVD tissue, adiponectin was not observed in NP and AF. However, both AdipoR1 and AdipoR2 were widely expressed in both human and rat IVD tissues, with no significant differences in expression levels between receptors. Furthermore, expression levels of AdipoR1 and AdipoR2 were gradually decreased with increased IVD degeneration severity. Interestingly, mRNA expression levels of TNF-α and IL-6 were significantly upregulated by IL-1β stimulation. TNF-α expression in the IL-1β+Ad 1.0 group was significantly lower than that in the IL-1β group in both NP and AF cells (P < 0.05). Finally, IL-6 expression was not affected by adiponectin treatment in IVD cells.

CONCLUSIONS

This study investigated for the first time the expression of adiponectin receptors in human and rat IVD cells. The findings indicate that adiponectin produced by the systemic or epidural adipose tissue may be involved in the pathomechanism of IVD degeneration.

The Influence of Common Medical Conditions on the Outcome of Anterior Lumbar Interbody Fusion

STUDY DESIGN

The authors retrospectively reviewed a consecutive series of 231 patients with anterior lumbar interbody fusion (ALIF).

OBJECTIVE

To determine the correlations among common medical conditions, demographics, and the natural history of lumbar surgery with outcomes of ALIF.

SUMMARY OF BACKGROUND DATA

Multiple spinal disorders are treated with ALIF with excellent success rates. Nonetheless, adverse outcomes and complications related to patients' overall demographics, comorbidities, or cigarette smoking have been reported.

METHODS

The age, sex, body mass index (BMI), comorbidities, history of smoking or previous lumbar surgery, operative parameters, and complications of 231 patients who underwent ALIF were analyzed. Regression analyses of all variables with complications and surgical outcomes based on total Prolo scores were performed. Two models predicting Prolo outcome score were generated. The first model used BMI and sex interaction, whereas the second model used sex, level of surgery, presence of diabetes mellitus, and BMI as variables.

RESULTS

At follow-up, the rate of successful fusion was 99%. The overall complication rate was 13.8%, 1.8% of which occurred intraoperatively and 12% during follow-up. The incidence of complications failed to correlate with demographics, comorbidities, smoking, or previous lumbar surgery (P>0.5). ALIF at T12-L4 was the only factor significantly associated with poor patient outcomes (P=0.024). Both models successfully predicted outcome (P=0.05), although the second model did so only for males.

CONCLUSIONS

Surgical level of ALIF correlated with poor patient outcomes as measured by Prolo functional scale. BMI emerged as a significant predictor of Prolo total score. Both multivariate models also successfully predicted outcomes. Surgical or follow-up complications were not associated with patients' preoperative status.

The Number of Patients and Therapeutic Profile of Spinal Stenosis Using Health Insurance Claims in Japan

STUDY DESIGN

Population-based retrospective descriptive study.

OBJECTIVE

To describe the number and therapeutic profile of patients with spinal stenosis at a large-scale community level using health insurance claims data.

SUMMARY OF BACKGROUND DATA

A few reports have documented the prevalence of spinal stenosis, and no report has described the therapeutic profile for spinal stenosis in a population base.

METHODS

We studied the claims data of National Health Insurance and Late-stage Elderly Health Insurance in a prefecture in Japan from April 2010 to March 2011. We considered patients to have spinal stenosis if their claims included at least one diagnosis coded as spinal stenosis for at least 1 month during the study period. Disease criteria were based on the International Classification of Diseases, 10th version. We then described the number and the therapeutic profile of the patients with spinal stenosis by age and sex.

RESULTS

Of 699,723 beneficiaries, 52,889 patients with spinal stenosis were identified. The number of patients with spinal stenosis per 1000 beneficiaries was 76, and those for the subgroups of age ≥ 65 years, ≥ 75 years, and ≥ 85 years were 128, 155, and 152, respectively. The number of patients per 1000 beneficiaries showed unimodal distribution, and the peak for males was 191 between the ages 95 to 99 years and that for females was 160 between the ages 80 to 84 years. Analgesics, prostaglandin E1, or both were prescribed to 40%, 2%, or 20% of patients with spinal stenosis, respectively. Physical therapy, nerve blocks, and surgery were done for 19%, 8%, and 0.4% of the patients, respectively. Approximately, 33% of patients did not receive any treatment.

CONCLUSION

There were a large number of patients with spinal stenosis in elderly people. Most of them received nonsurgical treatments. Health insurance claims data could be a useful source of surveillance for such common diseases as spinal stenosis.

LEVEL OF EVIDENCE

4.

Diabetes Mellitus, a New Risk Factor for Lumbar Spinal Stenosis: A Case-Control Study

OBJECTIVES

This study aimed to determine the prevalence of diabetes mellitus in patients with spinal stenosis and lumbar vertebral disk degeneration, and the correlation of diabetes with these diseases.

STUDY DESIGN

This is a cross-sectional study.

METHODS

This case–control study was performed during 2012–2014 with 110 patients suffering from lumbar spinal stenosis and 110 patients with lumbar disk herniation, who were diagnosed using clinical and radiological evidences. Additionally, 110 participants who were referred to the clinic and did not show clinical signs of degenerative diseases of the lumbar spine entered the study as a control group. Demographic data and medical histories of the patients were collected using checklists.

RESULTS

A total of 50 patients (15.2%) were diagnosed with diabetes, which comprised 32 (29.1%) in the stenosis group, 7 (6.4%) in the lumbar disk herniation group, and 11 (10%) in the control group. The prevalence of diabetes in women with spinal stenosis and women with lumbar disk herniation was 35.9% and 10.3%, respectively, whereas prevalence of diabetes in women was 10.9% in the control group. This difference was statistically significant in the spinal stenosis group in comparison with the controls (P < 0.0001). Conversely, no significant difference was found in men.

CONCLUSIONS

There is an association between diabetes and lumbar spinal stenosis. Diabetes mellitus may be a predisposing factor for the development of lumbar spinal stenosis.

Predictive Factors for Subjective Improvement in Lumbar Spinal Stenosis Patients with Nonsurgical Treatment: A 3-Year Prospective Cohort Study

Objective

To assess the predictive factors for subjective improvement with nonsurgical treatment in consecutive patients with lumbar spinal stenosis (LSS).

Materials and Methods

Patients with LSS were enrolled from 17 medical centres in Japan. We followed up 274 patients (151 men; mean age, 71 ± 7.4 years) for 3 years. A multivariable logistic regression model was used to assess the predictive factors for subjective symptom improvement with nonsurgical treatment.

Results

In 30% of patients, conservative treatment led to a subjective improvement in the symptoms; in 70% of patients, the symptoms remained unchanged, worsened, or required surgical treatment. The multivariable analysis of predictive factors for subjective improvement with nonsurgical treatment showed that the absence of cauda equina symptoms (only radicular symptoms) had an odds ratio (OR) of 3.31 (95% confidence interval [CI]: 1.50–7.31); absence of degenerative spondylolisthesis/scoliosis had an OR of 2.53 (95% CI: 1.13–5.65); <1-year duration of illness had an OR of 3.81 (95% CI: 1.46–9.98); and hypertension had an OR of 2.09 (95% CI: 0.92–4.78).

Conclusions

The predictive factors for subjective symptom improvement with nonsurgical treatment in LSS patients were the presence of only radicular symptoms, absence of degenerative spondylolisthesis/scoliosis, and an illness duration of <1 year.

Long-Term Results and Efficacy of Laminectomy with Fusion Versus Young Laminoplasty for the Treatment of Degenerative Spinal Stenosis

OBJECTIVE

In the treatment of degenerative lumbar stenosis, facet-sparing laminectomy with instrumented fusion (FSL) was recently almost totally replaced by less invasive, allegedly equally effective surgical techniques. We performed a long-term comparison between outcomes after Young laminoplasty (YL) as a representative of the less invasive technique and FSL.

METHODS

From December 4, 2000, to March 11, 2005, 56 patients with a history of neurogenic claudication and radiologically verified absolute lumbar stenosis were surgically treated. After applying inclusion and exclusion criteria, 44 patients were enrolled.

RESULTS

Using the Oswestry Disability Index scale, significant improvement on 1-year and 8-year follow-up examinations was noticed in the FSL and YL groups. The Oswestry Disability Index was significantly better in the FSL group compared with the YL group at the 8-year follow-up (27.82 ± 1.918 vs. 40.74 ± 2.163).

CONCLUSIONS

FSL is a more invasive and more expensive surgical technique than YL. In a short-term and long-term follow-up comparison, FSL is a more successful operative technique, and the difference increases over time in favor of FSL.

Metabolic Syndrome Components Are Associated with Intervertebral Disc Degeneration: The Wakayama Spine Study

OBJECTIVE

The objective of the present study was to examine the associations between metabolic syndrome (MS) components, such as overweight (OW), hypertension (HT), dyslipidemia (DL), and impaired glucose tolerance (IGT), and intervertebral disc degeneration (DD).

DESIGN

The present study included 928 participants (308 men, 620 women) of the 1,011 participants in the Wakayama Spine Study. DD on magnetic resonance imaging was classified according to the Pfirrmann system. OW, HT, DL, and IGT were assessed using the criteria of the Examination Committee of Criteria for MS in Japan.

RESULTS

Multivariable logistic regression analysis revealed that OW was significantly associated with cervical, thoracic, and lumbar DD (cervical: odds ratio [OR], 1.28; 95% confidence interval [CI], 0.92-1.78; thoracic: OR, 1.75; 95% CI, 1.24-2.51; lumbar: OR, 1.87; 95% CI, 1.06-3.48). HT and IGT were significantly associated with thoracic DD (HT: OR, 1.54; 95% CI, 1.09-2.18; IGT: OR, 1.65; 95% CI, 1.12-2.48). Furthermore, subjects with 1 or more MS components had a higher OR for thoracic DD compared with those without MS components (vs. no component; 1 component: OR, 1.58; 95% CI, 1.03-2.42; 2 components: OR, 2.60; 95% CI, 1.62-4.20; ≥3 components: OR, 2.62; 95% CI, 1.42-5.00).

CONCLUSION

MS components were significantly associated with thoracic DD. Furthermore, accumulation of MS components significantly increased the OR for thoracic DD. These findings support the need for further studies of the effects of metabolic abnormality on DD.

Mechanics and biology in intervertebral disc degeneration: a vicious circle

Intervertebral disc degeneration is a major cause of low back pain. Despite its long history and large socio-economical impact in western societies, the initiation and progress of disc degeneration is not well understood and a generic disease model is lacking. In literature, mechanics and biology have both been implicated as the predominant inductive cause; here we argue that they are interconnected and amplify each other. This view is supported by the growing awareness that cellular physiology is strongly affected by mechanical loading. We propose a vicious circle of mechanical overloading, catabolic cell response, and degeneration of the water-binding extracellular matrix. Rather than simplifying the disease, the model illustrates the complexity of disc degeneration, because all factors are interrelated. It may however solve some of the controversy in the field, because the vicious circle can be entered at any point, eventually leading to the same pathology. The proposed disease model explains the comparable efficacy of very different animal models of disc degeneration, but also helps to consider the consequences of therapeutic interventions, either at the cellular, material or mechanical level.

Alterations in intervertebral disc composition, matrix homeostasis and biomechanical behavior in the UCD-T2DM rat model of type 2 diabetes

Type 2 diabetes (T2D) adversely affects many tissues, and the greater incidence of discogenic low back pain among diabetic patients suggests that the intervertebral disc is affected too. Using a rat model of polygenic obese T2D, we demonstrate that diabetes compromises several aspects of disc composition, matrix homeostasis, and biomechanical behavior. Coccygeal motion segments were harvested from 6-month-old lean Sprague-Dawley rats, obese Sprague-Dawley rats, and diabetic obese UCD-T2DM rats (diabetic for 69 ± 7 days). Findings indicated that diabetes but not obesity reduced disc glycosaminoglycan and water contents, and these degenerative changes correlated with increased vertebral endplate thickness and decreased endplate porosity, and with higher levels of the advanced glycation end-product (AGE) pentosidine. Consistent with their diminished glycosaminoglycan and water contents and their higher AGE levels, discs from diabetic rats were stiffer and exhibited less creep when compressed. At the matrix level, elevated expression of hypoxia-inducible genes and catabolic markers in the discs from diabetic rats coincided with increased oxidative stress and greater interactions between AGEs and one of their receptors (RAGE). Taken together, these findings indicate that endplate sclerosis, increased oxidative stress, and AGE/RAGE-mediated interactions could be important factors for explaining the greater incidence of disc pathology in T2D.

The spinal stenosis pedometer and nutrition lifestyle intervention (SSPANLI): development and pilot

BACKGROUND CONTEXT

Owing to mobility limitations, people with lumbar spinal stenosis (LSS) are at risk for diseases of inactivity, including obesity. Therefore, weight management in LSS is critical. Body mass index is the strongest predictor of function in LSS, suggesting that weight loss may promote physical activity and provide a unique treatment option. We propose a lifestyle modification approach of physical activity and nutrition education, delivered through an e-health platform.

PURPOSE

The purpose of this study was to develop and pilot an e-health intervention aimed at increasing physical activity and decreasing fat mass in people with LSS.

STUDY DESIGN

The study design was based on intervention development and pilot.

PATIENT SAMPLE

Ten overweight or obese individuals with LSS were confirmed clinically and on imaging.

OUTCOME MEASURES

Self-reported measures were food record, Short-Form 36 (SF-36), pain scales, Swiss Spinal Stenosis Symptom and Physical Function Scales, Oswestry Disability Index (ODI), Pain Catastrophizing Questionnaire, Tampa Scale for Kinesiophobia, Center for Epidemiologic Studies(Depression) Scale, Behavioral Regular in Exercise Questionnaire, and Regulation for Eating Behavior Scale and physiologic measures were dual-energy X-ray absorptiometry (DXA), blood draw, 7-day accelerometry, self-paced walking test, and balance test.

METHODS

The e-health platform was developed.

INTERVENTION

during Week 1, participants received a pedometer and a personalized consultation with a dietitian and an exercise physiologist. For 12 weeks, participants logged on to the e-health Web site to access personal step goals, nutrition education videos, and a discussion board. Follow-up occurred at Week 13.

RESULTS

Nine participants had a mean age of 67.5±6.7 years (60% women). Significant improvements were observed for fat mass (DXA), trunk fat mass, symptom severity (Swiss Symptom Scale), energy intake, maximum continuous activity (accelerometry), and mental health (SF-36) (p<.05). Nonsignificant improvements were observed for waist circumference, pain, ODI, and obesity biomarkers. Seventy percent lost weight, 50% increased walking capacity, and 60% increased quality of life. The mean increase in steps was 15%.

CONCLUSIONS

The spinal stenosis pedometer and nutrition lifestyle intervention was shown to be feasible, attractive to participants, and effective in this small sample. This intervention provides people with LSS the opportunity to participate in their own health management, potentially improving access to care. Efficacy is currently being assessed in a randomized trial.

Surgical treatment of degenerative lumbar stenosis: comorbidities and complications

Objectives: To study the characteristics of patients who underwent surgical treatment of degenerative spinal stenosis in the last 10 years (2000&#226;&#8364;"2010) at the Hospital das Cl&#237;nicas da Faculdade de Medicina de Ribeir&#227;o Preto (USP-HCFMR) and correlate the postoperative complications and preoperative comorbidities found in the study population. Methods: Retrospective review of medical records and radiographs of patients with degenerative lumbar stenosis treated surgically. Descriptive analysis of data was done with SAS 9.0. Results: 92 patients were included, 47 (51.08%) males and 45 (48.91%) females, with ages ranging from 32 to 86 years (mean age of 64.27 years). The most prevalent comorbidities were hypertension (47.82%) and diabetes mellitus (25%). Twenty-three patients (25%) had two or more comorbidities. Postoperative infection was the most common complication found in 12 cases (13%). Patients with only one preoperative comorbidity showed similar complication rates compared to the population without comorbidities. However, patients with two or more comorbid conditions had a higher incidence of postoperative complications (p&lt;0.001). Conclusions: Comorbidities negatively influenced the outcome of surgical treatment of degenerative lumbar stenosis with higher rates of postoperative complications.

Physical and psychological comorbidity independently associated with spine-related disability

STUDY DESIGN

Cross sectional analysis of patient-reported spine-related disability and comorbidity.

OBJECTIVE

To determine if nonorthopedic physical and psychological comorbidity are independently associated with self-reported spine-related disability in patients scheduled for spine surgery.

SUMMARY OF BACKGROUND DATA

The association between psychological comorbidity and spine-related disability is well known; less is known about the contribution of nonorthopedic physical comorbidity to patients' ratings of spine-related disability.

METHODS

Several days before surgery, 175 patients with cervical problems and 538 patients with lumbar problems completed the Neck Disability Index and the Oswestry Disability Index, respectively; scores range from 0% to 100%; higher scores reflect more disability. The Charlson Comorbidity Index, a standard index of weighted major physical comorbidity, was used to dichotomize patients according to no major physical comorbidity (Charlson Comorbidity Index=0) or any major physical comorbidity (Charlson Comorbidity Index≥1). Psychological comorbidity was measured for depressive symptoms and anxiety with validated scales.

RESULTS

Mean age of patients with cervical problems was 54 years, 60% were males, mean Neck Disability Index score was 44%, and 25% had major physical comorbidity. In multivariate analysis controlling for younger age (P<0.0001) and female sex (P<0.0001), more depressive symptoms (P=0.0003), and having major physical comorbidity (P=0.02) were associated with worse Neck Disability Index scores. Mean age of patients with lumbar problems was 56 years, 55% were males, mean Oswestry Disability Index score was 56%, and 30% had major physical comorbidity. In multivariate analysis controlling for younger age (P=0.36) and female sex (P=0.002), more depressive symptoms (P<0.0001), and having major physical comorbidity (P=0.03) were associated with worse Oswestry Disability Index scores.

CONCLUSION

Psychological comorbidity and nonorthopedic physical comorbidity measured by a standard index are associated with patient-reported spine-related disability in patients undergoing cervical and lumbar spine surgery. Given that disability is a major indicator for surgery, how psychological and physical comorbidity influence patients' assessment of spine-related disability merits further investigation.

LEVEL OF EVIDENCE

2.

Body mass index and musculoskeletal pain: is there a connection?

Background

Back pain is one of the most common complaints that patients report to physicians and two-thirds of the population has an elevated body mass index (BMI), indicating they are either overweight or obese. It was once assumed that extra body weight would stress the low back and lead to pain, however, researchers have reported inconsistencies association between body weight and back pain. In contrast, more recent studies do indicate that an elevated BMI is associated with back pain and other musculoskeletal pain syndromes due to the presence of a chronic systemic inflammatory state, suggesting that the relationship between BMI and musculoskeletal pains be considered in more detail.

Objective

To describe how an elevated BMI can be associated with chronic systemic inflammation and pain expression. To outline measurable risk factors for chronic inflammation that can be used in clinical practice and discuss basic treatment considerations.

Discussion

Adiposopathy, or “sick fat” syndrome, is a term that refers to an elevated BMI that is associated with a chronic systemic inflammatory state most commonly referred to as the metabolic syndrome. The best available evidence suggests that the presence of adiposopathy determines if an elevated BMI will contribute to musculoskeletal pain expression. It is not uncommon for physicians to fail to identify the presence of adiposopathy/metabolic syndrome.

Conclusion

Patients with an elevated BMI should be further examined to identify inflammatory factors associated with adiposopathy, such as the metabolic syndrome, which may be promoting back pain and other musculoskeletal pain syndromes.

Combined anti-inflammatory and anti-AGE drug treatments have a protective effect on intervertebral discs in mice with diabetes

Objective

Diabetes and low back pain are debilitating diseases and modern epidemics. Diabetes and obesity are also highly correlated with intervertebral disc (IVD) degeneration and back pain. Advanced-glycation-end-products (AGEs) increase reactive-oxygen-species (ROS) and inflammation, and are one cause for early development of diabetes mellitus. We hypothesize that diabetes results in accumulation of AGEs in spines and associated spinal pathology via increased catabolism. We present a mouse model showing that: 1) diabetes induces pathological changes to structure and composition of IVDs and vertebrae; 2) diabetes is associated with accumulation of AGEs, TNFα, and increased catabolism spinal structures; and 3) oral-treatments with a combination of anti-inflammatory and anti-AGE drugs mitigate these diabetes-induced degenerative changes to the spine.

Methods

Three age-matched groups of ROP-Os mice were compared: non-diabetic, diabetic (streptozotocin (STZ)-induced), or diabetic mice treated with pentosan-polysulfate (anti-inflammatory) and pyridoxamine (AGE-inhibitor). Mice were euthanized and vertebra-IVD segments were analyzed by μCT, histology and Immunohistochemistry.

Results

Diabetic mice exhibited several pathological changes including loss in IVD height, decreased vertebral bone mass, decreased glycosaminoglycan content and morphologically altered IVDs with focal deposition of tissues highly expressing TNFα, MMP-13 and ADAMTS-5. Accumulation of larger amounts of methylglyoxal suggested that AGE accumulation was associated with these diabetic degenerative changes. However, treatment prevented or reduced these pathological effects on vertebrae and IVD.

Conclusion

This is the first study to demonstrate specific degenerative changes to nucleus pulposus (NP) morphology and their association with AGE accumulation in a diabetic mouse model. Furthermore, this is the first study to demonstrate that oral-treatments can inhibit AGE-induced ROS and inflammation in spinal structures and provide a potential treatment to slow progression of degenerative spine changes in diabetes. Since diabetes, IVD degeneration, and accumulation of AGEs are frequent consequences of aging, early treatments to reduce AGE-induced ROS and Inflammation may have broad public-health implications.

Dose- and time-dependent effect of high glucose concentration on viability of notochordal cells and expression of matrix degrading and fibrotic enzymes

PURPOSE

Diabetes mellitus is an important aetiological factor in intervertebral disc degeneration. The disappearance of notochordal cells in the nucleus pulposus is thought to be the starting point for intervertebral disc degeneration. A cellular effect of diabetes mellitus on apoptosis of notochordal cells and intervertebral disc degeneration has been recently reported. However, how the duration and severity of diabetes mellitus affects viability of notochordal cells and intervertebral disc degeneration is still unknown .

METHODS

Rat notochordal cells were isolated, cultured, and placed in either 10 % foetal bovine serum (FBS) (normal control) or 10 % FBS plus three different high glucose concentrations (0.1 M, 0.2 M, and 0.4 M) (experimental conditions) for one, three, five and seven days, respectively. We identified and quantified the degree of proliferation and apoptosis, caspase activities, and cleavages of Bid and cytochrome-c. In addition, we examined the cells for expression of matrix metalloproteinases (MMPs) and their tissue inhibitors of metalloproteinases (TIMPs).

RESULTS

Each three high glucose concentrations significantly decreased proliferation and increased apoptosis of notochordal cells from culture days one to seven in a dose-dependent manner. Compared with those of 10 % FBS, caspase-9 and -3 activities and cleavage of Bid and cytochrome-c were significantly increased in each three high glucose concentrations, accompanied by increased expression of MMP-1, -2, -3, -7, -9, and -13 and TIMP-1 and -2.

CONCLUSIONS

High glucose concentration significantly decreased proliferation and increased apoptosis of notochordal cells via the intrinsic pathway with dose- and time-dependent effects. We also found that expression of MMPs and TIMPs was increased with dose- and time-dependent effects. Therefore, these results suggest that aggressive glucose control from an early stage of diabetes mellitus should be recommended to prevent or limit intervertebral disc degeneration.

Health-related quality of life and comorbidities associated with lumbar spinal stenosis

BACKGROUND CONTEXT

Spinal stenosis is one of the most commonly diagnosed pathologies of the lumbar spine and the leading indication for spine surgery in adults aged 65 years and older. Yet, the burden of lumbar spinal stenosis (LSS) alone, and in combination with common comorbidities, on health-related quality of life (HRQL) is unknown as are comorbidities specifically associated with this chronic condition.

PURPOSE

To estimate the illness burden of LSS on HRQL, adjusting for the effects of specific comorbidities, age, and gender, and investigate whether specific comorbidities are associated with the condition.

STUDY DESIGN/SETTING

A community-based cohort of 245 patients diagnosed with LSS was assembled and compared with a representative sample of 7,489 adults from the base population of Albertans responding to the Canadian Community Health Survey on HRQL and comorbidities.

METHODS

Health-related quality-of-life data were acquired through interviews for both groups using the Health Utilities Index Mark 3 (HUI3). Both groups were also queried about the presence of 13 specific chronic conditions. Linear regression was used to model HUI3 scores as a function of group, age, gender, and specific comorbid conditions. Logistic regression was used to compare the odds of having particular comorbid conditions between the LSS and general population groups.

RESULTS

The mean unadjusted overall HUI3 scores were 0.60 for the LSS group and 0.85 for the general population (1=perfect health). After adjustment, HRQL deficits four times that deemed a clinically important difference remained between the groups. Controlling age and gender, the prevalence of arthritis, migraines, hypertension, and incontinence was significantly greater in the LSS group as compared with the general population sample.

CONCLUSIONS

Diagnosed LSS is associated with a very substantial burden of illness that is compounded by associated comorbidities, with implications for clinical care, health-care policy decisions, and research. Attention to comorbidities is particularly important in LSS.

MR imaging assessment of lumbar intervertebral disk degeneration and age-related changes: apparent diffusion coefficient versus T2 quantitation

BACKGROUND AND PURPOSE

T2 and ADC mappings are 2 quantitative MR imaging tools for assessing IVDD. This study aimed to compare these 2 measures in detecting IVDD and its age-related changes.

MATERIALS AND METHODS

Thirty-seven asymptomatic volunteers and 28 patients with back pain or sciatica were examined, and their lumbar disk T2 and ADC maps were quantified via sagittal imaging protocols at 1.5T. For all participants, the Pfirrmann system was used by 2 radiologists for grading disks. T2 and ADC values in the inner portion of disks were measured, and their variances in different grades were analyzed by 1-way ANOVA testing. The ability of T2 and ADC measures to differentiate IVDD grades was compared on the basis of their ROC curves. For asymptomatic subjects, the correlations between age and the 2 MR imaging measures were assessed by the Pearson correlation test.

RESULTS

Both T2 and ADC values were found to decrease with the increasing Pfirrmann grades except T2 in grade V. Significant T2 differences were seen among grades I-IV, but not between grades IV and V. There were no significant ADC differences among grades I-III. Moreover, the areas under the ROC curves differed significantly (0.95 and 0.67 for T2 and ADC, respectively). Linear regression analysis revealed that T2 yielded more significant correlation with age (r = -0.77) than ADC did (r = -0.37).

CONCLUSIONS

T2 quantitation provides a more sensitive and robust approach for detecting and characterizing the early stage of IVDD and age-related disk changes.

Chronic exertional compartment syndrome in diabetes mellitus

AIMS

Intermittent claudication is common in diabetes mellitus and usually (attributed to arterial disease) . However, a proportion of patients with diabetes have symptoms of claudication without signs of vascular disease and these patients were evaluated for chronic exertional compartment syndrome.

METHODS

Forty-two patients with diabetes (10 men, 32 women), earlier investigated at diabetic clinics because of claudication with no explanation for the symptoms, were examined. Their median age was 48 years (18-72 years) and the median duration of diabetes was 29 years (1-45 years). Thirty-one patients had Type 1 diabetes, 11 had Type 2 diabetes and 29 had diabetic complications. All were investigated clinically, with radiography, bone scan and intramuscular pressure measurements.

RESULTS

Thirty-eight of 42 patients with diabetes were diagnosed with chronic exertional compartment syndrome of the lower leg and 32 were treated surgically. Thirty-one patients were operated with fasciotomy of the anterior compartment and 18 also with fasciotomy of the posterior compartment. Additionally, one patient had only fasciotomy of the posterior compartment. Fourteen of 32 surgically treated patients (27 legs) were followed for more than 2 years and rated the post-operative outcome as excellent or good in 21 of the treated legs. The walking distance before lower leg pain increased in all but one patient and seven patients reported unrestricted walking ability.

CONCLUSIONS

Chronic exertional compartment syndrome should be considered as a differential diagnoses in patients with diabetes and exercise-related lower leg pain. The results after surgery are encouraging and the increased walking ability is beneficial in the treatment of diabetes.

Effect of hyperglycemia on apoptosis of notochordal cells and intervertebral disc degeneration in diabetic rats

Object

Diabetes mellitus is thought to be an important etiologic factor in intervertebral disc degeneration. It is known that notochordal cells gradually disappear from the nucleus pulposus (NP) of the intervertebral disc with age by undergoing apoptosis. What is not known is whether diabetes has an effect on apoptotic rates of notochordal cells. The purpose of this study was to investigate the effect of hyperglycemia on apoptosis of notochordal cells and intervertebral disc degeneration in age-matched OLETF (diabetic) and LETO (control) rats.

Methods

Lumbar disc tissue (L1–2 through L5–6), including cranial and caudal cartilaginous endplates, was obtained from 6- and 12-month-old OLETF and LETO rats (40 rats, 10 in each of the 4 groups). The authors examined the NP using TUNEL, histological analysis, and Western blot for expression of matrix metalloproteinase (MMP)–1, -2, -3, and -13, tissue inhibitor of metalloproteinase (TIMP)–1 and -2, and Fas (apoptosis-related protein). The apoptosis index of notochordal cells was calculated. The degree of transition of notochordal NP to fibrocartilaginous NP was classified on a scale ranging from Grade 0 (no transition) to Grade 4 (transition > 75%). The degree of expression of MMP-1, -2, -3, and -13, TIMP-1 and -2, and Fas was evaluated by densitometry.

Results

At 6 and 12 months of age, OLETF rats showed increased body weight and abnormal 2-hour glucose tolerance tests compared with LETO rats. The apoptosis index of notochordal cells was significantly higher in the OLETF rats than in the LETO rats at both 6 and 12 months of age. The degree of transition of notochordal NP to fibrocartilaginous NP was significantly higher in the OLETF rats than in the LETO rats at 6 and 12 months of age. The expression of MMP-1, -2, -3, and -13, TIMP-1, and Fas was higher in the OLETF rats at 6 and 12 months of age. The expression of TIMP-2 was significantly higher in the OLETF rats than in the LETO rats at 6 months of age, but not at 12.

Conclusions

The findings suggest that diabetes is associated with premature, excessive apoptosis of NP notochordal cells. This results in an accelerated transition of a notochordal NP to a fibrocartilaginous NP, which leads to early intervertebral disc degeneration. It remains to be determined if these premature changes are due to hyperglycemia or some other factors associated with diabetes. Understanding the mechanism by which diabetes affects disc degeneration is the first step in designing therapeutic modalities to delay or prevent disc degeneration caused by diabetes mellitus.