Diabetes, Metabolic Syndrome and Obesity (Jan 2019)

Elevated free fatty acid level is associated with insulin-resistant state in nondiabetic Chinese people

  • Xin YL,
  • Wang Y,
  • Chi J,
  • Zhu X,
  • Zhao H,
  • Zhao S,
  • Wang Y

Journal volume & issue
Vol. Volume 12
pp. 139 – 147

Abstract

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Yanlu Xin,1 Yunyang Wang,1 Jingwei Chi,2 Xvhua Zhu,3 Hui Zhao,4 Shihua Zhao,1,2 Yangang Wang1 1Department of Endocrinology and Metabolism, Affiliated Hospital of Qingdao University, Qingdao, China; 2Laboratory of Thyroid Disease, Affiliated Hospital of Qingdao University, Qingdao, China; 3Department of Endocrinology and Metabolism, Second People’s Hospital of Qingdao West Coast, Qingdao, China; 4Department of Endocrinology and Metabolism, Hiser Medical Center of Qingdao, Qingdao, China Background: Free fatty acids (FFAs) are associated with insulin secretion and insulin resistance. However, the associations among FFAs, obesity, and progression from a normal to a prediabetic state are unclear. Methods: Nondiabetic subjects (5,952) were divided in two groups according to their body mass index (BMI): obese subjects (BMI ≥24 kg/m2) and nonobese subjects (BMI <24 kg/m2). Clinical and multiple glucolipid metabolism data were collected. The homeostasis model assessment for insulin resistance (HOMA-IR) and β-cell function (HOMA-β) was used. HbA1c level between 5.7% and 6.4% was considered prediabetic. Nonparametric tests, one-way ANOVA, and linear correlation analysis were performed. R and SPSS 23.0 software programs were used to analyze the results. Results: A U-shaped relationship between FFAs and HOMA-IR was observed. After adjusting for potential confounders, the turning points of FFA levels in the curves were 0.54 mmol/L in the nonobese group and 0.61 mmol/L in the obese group. HOMA-IR levels decreased with increasing FFA concentrations before the turning points (regression coefficient [β]= – 0.9, P=0.0111, for the nonobese group; β=0.2, P=0.5094, for the obese group) and then increased (β=0.9, P=0.0069, for the nonobese group; β=1.5, P=0.0263 for the obese group) after the points. Additionally, our study also identified that FFAs were associated with the prediabetes status in obese individuals. Conclusion: FFA levels were associated with insulin resistance in nondiabetic subjects, and HOMA-IR in nonobese individuals was more sensitive to FFA changes. Monitoring and controlling plasma FFA levels in obese subjects is significant in decreasing insulin resistance and preventing diabetes. Keywords: FFA, insulin resistance, T2DM, obesity, HOMA-IR

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