Fasting Plasma Linoleylglycerolphosphocholine As a Biomarker of Insulin Resistance in Non-Diabetic Adult
Presentation Number: LB MON 67
Date of Presentation: April 3rd, 2017
Freddy JK Toloza1, Maria Camila Perez-Matos1, Maria Laura Ricardo-Silgado2, Martha Catalina Morales-Alvarez1, Jose Oscar Mantilla-Rivas1, Jairo Arturo Pinzon-Cortes1, Maritza Perez-Mayorga3, Elizabeth Jimenez1, Edwin Guevara1 and Carlos Olimpo Mendivil*4
1Universidad de los Andes, Bogota, Colombia, 2Universidad de los Andes, Bogota, 3Universidad Militar Nueva Granada, Bogota, 4Fundacion Santa Fe de Bogota
Phosphatidylcholines (PC) are some of the most abundant components of cell membranes. The presence of different fatty acids in the sn-1 and sn-2 positions of their glycerol backbone gives raise to multiple PC species. Linoleylglycerolphosphocholine (LGPC) is a lysophospholipid and one of such PC subtypes, which has been postulated as a biomarker of insulin resistance (IR) and risk of progression to diabetes. The association of LGPC with IR / insulin sensitivity has not been tested in non-Caucasian populations.
To explore the association between fasting plasma LGPC levels and objective measures of insulin sensitivity in Colombian adults.
We studied 81 subjects (mean age 51.4) with different metabolic profiles (33% normal weight, 54% overweight, 13% obese, mean HbA1c 5.5%). All participants underwent a 5-point OGTT with determination of HOMA-IR, Insulin Sensitivity Index [ISI], incremental area under the insulin curve [iAUCins], and Corrected Insulin Response at 30 minutes [CIR-30]. A subgroup of 21 participants additionally underwent a hyperinsulinemic-euglycemic clamp. Plasma LGPC was determined using High Performance Liquid Chromatography - Time of Flight Mass Spectrometry in fasting samples. IR was defined as belonging to the highest quartile of iAUCins, or as belonging to the lowest quartile of whole-body insulin-stimulated glucose disposal at steady state (M).
Mean plasma LGPC levels were 15,4 +/-7,6 ng/mL in women and 14,1 +/- 7,3 ng/mL in men. LGPC did not correlate with BMI, total body fat percent, abdominal fat percent, lean body mass, abdominal circumference, blood pressure, HbA1c, Log-triglycerides or HDL cholesterol. LGPC was not linearly correlated with any of the OGTT-derived IR indexes, except for a non-significant negative correlation with the CIR-30 (r= -0.21, p=0.11). However, LGPC exhibited a significant negative correlation with insulin-stimulated glucose disposal (r= -0.56, p=0.029) and good discriminative power: A cutoff of 8,6 micrograms/mL had 100% sensitivity and 67% specificity for the detection of IR according to the M-value definition (C-statistic 0.85).
Contrary to expectation and to prior evidence, we found a negative correlation between plasma LGPC and insulin sensitivity. LGPC is a promising biomarker of IR, but the direction of its association with insulin sensitivity may differ across populations.
Nothing to Disclose: FJT, MCP, MLR, MCM, JOM, JAP, MP, EJ, EG, COM