Spinal epidural lipomatosis is a previously unrecognized manifestation of metabolic syndrome

BACKGROUND CONTEXT

Spinal epidural lipomatosis (SEL) is a condition in which excess lumbar epidural fat (EF) deposition often leads to compression of the cauda equina or nerve root. Although SEL is often observed in obese adults, no systematic research investigating the potential association between SEL and metabolic syndrome has been conducted.

PURPOSE

To elucidate potential association between SEL and metabolic syndrome.

STUDY DESIGN

An observational study used data of a medical checkup.

PATIENT SAMPLE

We retrospectively reviewed data from consecutive subjects undergoing medical checkups. A total of 324 subjects (174 men and 150 women) were enrolled in this study.

OUTCOME MEASURES

The correlation of EF accumulation with demographic data and metabolic-related factors was evaluated.

METHODS

The degree of EF accumulation was evaluated based on the axial views of lumbar magnetic resonance imaging. Visceral and subcutaneous fat areas were measured at the navel level using abdominal computed tomography. Metabolic syndrome was diagnosed according to the criteria of the Japanese Society of Internal Medicine. The correlation of SEL with metabolic syndrome and metabolic-related conditions was statistically evaluated.

RESULTS

The degree of EF accumulation demonstrated a significant correlation to body mass index, abdominal circumference, and visceral fat area. However, age, body fat percentage, and subcutaneous fat area showed no correlation with the degree of EF accumulation. Logistic regression analysis revealed that metabolic syndrome (odds ratio OR]=3.8, 95% confidence interval CI]=1.5–9.6) was significantly associated with SEL. Among the diagnostic criteria for metabolic syndrome, visceral fat area ≥100 cm² (OR=4.8, 95% CI=1.5–15.3) and hypertension (OR=3.5, 95% CI=1.1–11.8) were observed to be independently associated with SEL.

CONCLUSION

This is the first study to demonstrate that metabolic syndrome is associated with SEL in a relatively large, unbiased population. Our data suggest that metabolic-related conditions are potentially related to EF deposition and that SEL could be a previously unrecognized manifestation of metabolic syndrome.