Lumbar epidural lipomatosis is associated with visceral fat and metabolic disorders

Shingo Morishita, Yoshiyasu Arai, Toshitaka Yoshii, Kenichiro Sakai, Takashi Hirai, Atsushi Okawa

Lumbar spinal epidural lipomatosis (LEL) is a condition characterized by excessive deposition of epidural fat in the spinal canal. Metabolic abnormalities may be associated with LEL, but few validated reports exist. Thus, we investigated the association between LEL and metabolic disorders in this study. A total of 218 patients who had neurological symptoms due to neural compression in the lumbar spinal canal were examined by magnetic resonance imaging (MRI), abdominal computed tomography (CT) scans and blood tests. We evaluated the epidural fat, dural sac and spinal canal areas using MRI, and the visceral fat and subcutaneous fat areas using abdominal CT. We compared the patients' demographics and the radiological parameters between the LEL and non-LEL patients. There were 58 LEL patients and 160 non-LEL patients. The LEL group included more men than women. In the MRI measurement, the dural sac area was similar between the LEL and non-LEL patients; however, the epidural fat/spinal canal ratio was much greater in the LEL group. In the LEL patients, factors associated with metabolic disorders, such as visceral fat area, uric acid (UA) and insulin levels, were significantly greater, compared to the non-LEL patients. In the logistic regression analysis, UA and visceral fat area were the independent explanatory factors in the pathogenesis of LEL. LEL patients had significantly more visceral fat and increased levels of insulin, UA and ferritin, which are closely related with metabolic disorders. This study indicates that the increased epidural fat in the spinal canal seen in the LEL patients is associated with metabolic syndrome. These slides can be retrieved under Electronic Supplementary material.