Fatty acid correlations with HOMA-IR and HOMA-% β are differentially dictated by their serum free and total pools and flaxseed oil supplementation

Abstract

Objective. The intent of the present study was to test two hypotheses. The primary hypothesis was that there would be differences between blood serum individual free fatty acids (SIFFA) and serum individual total fatty acids (SITFA) in terms of their different relationships (correlations) to each of homeostatic model assessment-individual insulin resistance (HOMA-IR) and homeostatic model assessment-individual insulin resistance-percentage β-cell function (HOMA-% β) remaining in human type 2 diabetic patients with pre-flaxseed oil (FXO) and pre-safflower oil (SFO) administration. The secondary hypothesis was that FXO (rich in alpha-linolenic acid, ALA) supplementation would alter these correlations differently in the SIFFA and STIFFA pools in comparison with the placebo SFO (poor in ALA). Methods. Patients were recruited via a newspaper advertisement and two physicians. All patients came to visit 1 and three months later to visit 2. At visit 2, the subjects were randomly assigned (double-blind) to flaxseed or safflower oil (placebo) treatment for three months until visit 3. Results. There were pre-intervention differences in the SIFFA and STIFA pool's relationships with each of HOMA-IR and HOMA-% β. These relatioships remained either unchanged or became significant after intervention (treatment or placebo). There was a negative correlation found between HOMA-IR and serum free ALA (SFALA) mol % after FXO. Serum total ALA (STALA) mol % had no significant correlations with HOMA-IR and HOMA- % β before and after flaxseed oil administration. Conclusions. The SIFFA and SITFA pools have different relationships with HOMA-IR and HOMA-% β for each of pre- and post-intervention. It is concluded that the data support both the primary and the secondary hypotheses indicating that they are correct.

Keywords: alpha-linolenic acid; flax-seed oil; insulin resistance; pancreatic β-cell function; safflower oil; serum individual free and total fatty acids composition; type 2 diabetes.