Predictive value of serum dihomo-γ-linolenic acid level and estimated Δ-5 desaturase activity in patients with hepatic steatosis

Summary Background Hepatic steatosis is considered one of the features of metabolic syndrome (MetS). Polyunsaturated fatty acid (PUFA) metabolism is modulated in obesity. However, it has yet to be fully elucidated whether a serum PUFA profile is associated with hepatic steatosis. Objective We aimed to clarify the relationship between a serum PUFA profile and liver lipid content. Methods A cross-sectional study was conducted on 288 patients with dyslipidemia, diabetes, or coronary artery disease on statin therapy. Several PUFAs were measured, including eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), dihomo-γ-linolenic acid (DGLA) and arachidonic acid (AA) in serum lipids, and Δ-5 desaturase (D5D) activity was estimated by AA to DGLA ratio. Abdominal computed tomography (CT) measured visceral fat area (VFA) and the ratio of CT attenuation for liver to spleen (L/S). Results The L/S ratio showed significant correlations with serum DGLA level and D5D activity ( p < 0.0001 for both). Serum DGLA level and D5D activity were significantly correlated with body mass index (BMI) or VFA, and with Homeostasis Model Assessment-Insulin Resistance (HOMA-IR) ( p < 0.0001 for all). Multivariate logistic analysis revealed that a high DGLA level or low D5D activity was a significant determinant for hepatic steatosis ( p < 0.0001 for both) independent of BMI and HOMA-IR. ROC analysis revealed that they significantly enhanced the value of MetS-related factors in predicting hepatic steatosis ( p < 0.05 for both). Conclusions A high DGLA level and low D5D activity in serum lipids may be useful markers predicting hepatic steatosis incrementally to MetS-related conventional factors.