Scientific Reports (Aug 2021)

Close association between non-alcoholic fatty liver disease and ossification of the posterior longitudinal ligament of the spine

  • Tsutomu Endo,
  • Yoshinao Koike,
  • Hideaki Miyoshi,
  • Yuichiro Hisada,
  • Ryo Fujita,
  • Ryota Suzuki,
  • Masaru Tanaka,
  • Takeru Tsujimoto,
  • Yukitoshi Shimamura,
  • Yuichi Hasegawa,
  • Masahiro Kanayama,
  • Tomoyuki Hashimoto,
  • Fumihiro Oha,
  • Naoki Noro,
  • Kiyofumi Komano,
  • Misaki Ishii,
  • Yoichi M. Ito,
  • Norimasa Iwasaki,
  • Masahiko Takahata

DOI
https://doi.org/10.1038/s41598-021-96714-9
Journal volume & issue
Vol. 11, no. 1
pp. 1 – 10

Abstract

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Abstract Ossification of the posterior longitudinal ligament (OPLL) of the spine is a disease of unknown etiology occurring frequently in individuals with metabolic disturbances. Obesity has been suggested as a potential risk factor for the severity of OPLL. We aimed to investigate whether non-alcoholic fatty liver disease (NAFLD) is associated with OPLL severity. We assessed the severity of NAFLD by a liver-to-spleen (L/S) ratio on computed tomography (CT) scans of 85 symptomatic OPLL patients at a single institution in Japan. We also assessed the severity of OPLL by CT reconstruction sagittal and axial images. The prevalence of NAFLD in middle-aged patients (age < 70 years, n = 50) was 80.3%, which was 2.5–8 times higher than that in the general Japanese population (9–30%). The ossification index of the spinal ligaments increased in proportion to the severity of fatty liver. The L/S ratio was revealed as a significant risk factor associated with the total ossification index (standardized β: -0.40, 95% confidence interval − 54.34 to − 4.22). This study suggests the potential contribution of NAFLD to the progression of OPLL. The close association between NAFLD and OPLL demonstrated in this study warrants further study to elucidate the causal nature of this relationship.