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

Abstract

Background:

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.

Aim

To explore the association between fasting plasma LGPC levels and objective measures of insulin sensitivity in Colombian adults.

Methods:

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).

Results

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).

Conclusions

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