diabetes and disk herniation

Strong Association of Lumbar Disk Herniation with Diabetes Mellitus: A 12-year Nationwide Retrospective Cohort Study

A study using Taiwan’s National Health Insurance database found a strong link between diabetes mellitus and lumbar disc herniation, revealing a significant discovery involving over 19 million people over a twelve-year period and highlighting the importance of understanding these associations.1

The study highlights that individuals with diabetes are more likely to develop Lumbar Disc Herniation (LDH) than those without diabetes and more than twice as likely to do so, based on a 12-year cohort study.

 

Background

Diabetes mellitus (DM) is a chronic disease with elevated blood glucose levels and various comorbidities. Types 1 and 2 are the two primary forms, with type 2 accounting for approximately 90% of DM cases. Type 1 DM, also known as autoimmune DM, is characterized by insulin deficiency and hyperglycemia caused by the elimination of pancreatic β-cells. DM can affect various organ systems, leading to severe complications over time. Individuals with type 2 DM are at risk of both microvascular and macrovascular complications, including retinopathy, nephropathy, neuropathy, and cardiovascular comorbidities. Insulin resistance and impaired insulin secretion are the primary defects of type 2 DM.

Lumbar disk herniation (LDH) is a common cause of lower back and unilateral leg pain, affecting a significant portion of the population. It occurs during the fourth and fifth decades of life and is a lifetime prevalence of 10%. The prevalence of severe intervertebral disc degeneration in the lumbar region has increased in individuals aged 20s, 30s, 50s, and 70s. Approximately 5-20 cases of LDH per 1,000 adults occur annually, with 95% of herniations occurring at L4-L5 or L5-S1.

The relationship between DM and lumbar disk degeneration has been the subject of research, but findings remain inconsistent. Some studies have reported cases wherein DM is a risk factor in patients with multiple disk herniation. Type 2 DM is significantly associated with lumbar spine disorders and frequent spinal procedures, while another study revealed a positive relationship between DM and lumbar disk diseases, including LDH. However, no conclusive evidence suggests that insulin-dependent DM has a significant impact on bone density or disk degeneration.

Discussion Points

The occurrence of both type 1 and type 2 diabetes mellitus (DM) has increased in recent years, presenting challenges and complications for a large proportion of the population. Individuals with DM display elevated levels of lumbar degeneration (LDH), suggesting that inadequate long-term management of DM may contribute to the development of LDH and potentially increase the chances of requiring surgical intervention. Degenerative disk disease is a significant healthcare issue, leading to persistent and often intense back pain that has a detrimental impact on the patient’s wellbeing and contributes to rising healthcare expenses. Understanding the risk factors associated with lumbar disk degeneration is crucial to implementing strategies that prevent or slow disease development and progression.

Recent studies indicate a higher vulnerability to intervertebral disk disease in females compared with males, but the specific impact of DM on intervertebral disk degeneration based on differences in sex remains unclear. Males bear a lower risk of LDH than females, and obesity and DM are more prevalent in obese individuals. Obesity was found to increase the risk of LDH (aHR, 1.12; 95% Cl, 1.05−1.19).

Associations were also found between dyslipidemia and LDH levels, but the relationship between serum lipid levels and back pain remains under debate. Some theories propose that advanced atherosclerosis may play a role in micro-vessel disease and spinal disk degeneration. Abnormal lipid levels have also been suggested as a potential mechanism that leads to atherosclerosis in the blood vessels of the lumbar region, which in turn can cause low back pain.

Smoking was shown to negatively influence LDH levels, likely due to microangiopathy. Smokers had a greater probability of suffering from LDH (aHR, 1.18; 95% Cl, 1.11−1.26) compared with nonsmokers. Two potential mechanisms for disk degeneration caused by smoking have been postulated: (1) downregulation of glycosaminoglycan biosynthesis and cell proliferation mediated by nicotine, and (2) decreased supply of nutrients to the intervertebral disk.

Lumbar degenerative disk disease is associated with male sex, HbA1c levels, and venous glucose. A Mendelian randomization analysis revealed a causal effect of type 2 DM on degenerative disk disease that persisted even when adjusted to BMI. Magnetic resonance imaging revealed a strong correlation between the severity and duration of DM and the presence of Modic changes. DM is also associated with poor outcomes following lumbar discectomy and cervical laminoplasty, including increased risk of postoperative mortality, surgical site infection, deep venous thrombosis, and prolonged hospitalization after spinal surgery.

Modic Spine Model

The intervertebral disk (ID) is a crucial component of the spinal cord, and its degeneration can be attributed to various factors. High preoperative HbA1c levels and long-term diabetes mellitus (DM) are risk factors for poor cervical laminoplasty outcomes in patients with DM and cervical spondylotic myelopathy. Hyperglycemia has been linked to the formation of advanced glycation end products in the nucleus pulposus, contributing to the progression of disk degeneration. Recent animal studies have also examined the association between hyperglycemia and intervertebral disk degeneration.

In a rat model, hyperglycemia stimulated disk autophagy, a process of cellular self-degradation, and accelerated stress-induced senescence in nucleus pulposus cells. Autophagy in nucleus pulposus and annulus fibrosus cells also appears to play a significant role in lumbar degenerative diseases. However, clinical studies have not established a conclusive association between DM and the rate of recurrent lumbar degenerative herniation (LDH).

lumbar disc herniation
Disc herniation model showing nuclear movement.

The administration of AHMs, such as SUs or meglitinides, was found to be significantly associated with an increased risk of LDH. Furthermore, the simultaneous use of multiple AHMs, suggesting inadequate blood sugar control, was significantly associated with an increased risk of LDH. Conversely, the use of metformin, DPP4is, SGLT2is, or insulin was significantly associated with a lower risk of LDH.

This study demonstrated that participants who used AHMs were at a higher risk of LDH than those who did not. Patients who were co-administered >2 AHMs were at a significantly higher risk of developing LDH than those who were co-administered <2 AHMs. These findings suggest that patients with poorly controlled DM tend to exhibit more severe disk degeneration than those with adequate control, and that DM is a risk factor for LDH, with an effect dependent on the duration and level of disease control.

Despite the limitations of this study, it aimed to evaluate the overall correlation between DM burden and LDH levels. Future investigations should consider conducting smaller and more targeted studies to delve into more precise inquiries.

Conclusion

Given that diabetes and LDH are closely linked, a full diabetes treatment plan should include careful medication selection, close tracking of blood glucose levels, and changes in behavior. Finding and treating LDH early can help patients improve and make this long-term illness less of a drag.

Scientists are trying to figure out where these diseases came from. It could change how doctors find and treat their patients if they discover anything significant. They could learn more about health in general if they looked into the link between diabetes and lumbar disc herniation in more depth.