The relationship between Obesity and Sciatica as a risk factor

Sciatica and lumbar disc herniation are highly disabling low back conditions. Sciatica is characterized by radiating pain down the leg due to nerve root compression, often caused by a herniated disc.

Lumbar radicular pain, including sciatica, is common and has a higher impact on work disability compared to nonspecific low back pain. The causes of lumbar radicular pain and sciatica are not well known but are believed to be influenced by various factors, including occupational workload, body height, and lifestyle choices.

Obesity is associated with musculoskeletal disorders, including lumbar radicular pain and sciatica. A meta-analysis was reported by literature to determine the association between overweight/obesity and lumbar radicular pain or sciatica..

A total of 43 relevant studies were included in the meta-analysis, examining the association between weight-related factors and lumbar radicular pain or sciatica. The analysis comprised 8 cross-sectional studies, 7 case-control studies, and 11 cohort studies.

The studies investigated outcomes such as lumbar radicular pain, clinically defined sciatica, hospitalization due to sciatica, and surgery for lumbar disc herniation. The meta-analysis included data on overweight, overweight/obesity, and obesity from various studies.

The studies in the meta-analysis showed varying levels of heterogeneity. The association between obesity and clinically defined sciatica had moderate heterogeneity, while the association between overweight/obesity and surgery for lumbar disc herniation had high heterogeneity.

Meta-regression analysis indicated that the heterogeneity was influenced by the type of outcome and was not explained by study design or biases. Excluding specific studies reduced the heterogeneity to 0% for both clinically defined sciatica and surgery for lumbar disc herniation.

The meta-analysis of 26 studies reported by literature found a significant association between overweight/obesity or obesity and the condition studied. The analysis did not reveal any publication bias or missing studies.

The findings of the meta-analysis indicate a consistent link between being overweight or obese and a higher likelihood of developing lumbar radicular pain and sciatica. This association holds true for both men and women, and there is also evidence of a dose-response relationship, implying that higher levels of overweight or obesity further increase the risk.

The study explored a range of outcomes, including self-reported symptoms and clinically verified conditions. The associations between overweight/obesity and lumbar radicular pain or sciatica were consistently modest, similar to those observed with nonspecific low back pain.

While there were variations in the prevalence, incidence, and recovery rates of the studied outcomes based on sex, the meta-analysis did not identify any differences between men and women regarding the association between overweight/obesity and lumbar radicular pain or sciatica.

Unfortunately, the included studies did not provide data on age-specific associations. The mechanisms by which obesity increases the risk of lumbar radicular pain and sciatica are not fully understood.

However, obesity is known to contribute to chronic inflammation and the release of inflammatory substances from excess adipose tissue. Leptin, an adipokine associated with obesity, may also play a role, but its specific involvement in the obesity-sciatica link is still unclear.

According to a trial involving patients with sciatica, obesity is linked to a delayed healing process for disc injuries. Regardless of the type of treatment received, obese individuals showed less improvement in back-related disability. Furthermore, obesity raises the likelihood of experiencing recurrent disc herniation following lumbar microdiscectomy.

The nutrition of intervertebral discs may be disrupted by obesity, leading to impaired healing. A study revealed that individuals with higher BMI had a significant likelihood of developing lumbar artery occlusion among those with sciatica, suggesting a possible connection between obesity and sciatica through this pathway.

The results of a meta-analysis can be affected by publication bias, but in this case, no evidence of such bias was found. Some smaller studies on lumbar radicular pain or sciatica may have underestimated the associations with overweight/obesity as their main focus was not specifically on exploring this relationship.

Additionally, the use of different BMI cutoff points to define overweight and obesity in studies could have influenced the results.

The sensitivity analyses carried out in this meta-analysis provided further support for the reliability of the results. The relationship between overweight/obesity and sciatica remained consistent across genders, regardless of study design, response rates, and methods used to assess weight and height.

The associations of overweight/obesity with lumbar radicular pain and hospitalization for sciatica were not influenced by confounding factors. In summary, the study consistently identified both overweight and obesity as risk factors for lumbar radicular pain and sciatica, with a clear dose-response relationship observed in both men and women.