Gas Chromatography results interpretation: absolute amounts versus relative percentages

Abstract

Impaired fatty acid metabolism has been implied in a number of diseased states such as multiple sclerosis, sudden cardiac death, insulin resistance, atherosclerosis and hypertension (Blaak, 2003; Oram & Bornfeldt, 2004; Pilz et al., 2007; Sarafidis & Bakris, 2007; Hon et al., 2009a, 2009b). The fatty acid status may be assessed in plasma, platelets, red blood cells, white blood cells and brain tissue (Zamaria, 2004, Hon et al., 2009a). However, the plasma fatty acid profile may vary considerably, whereas red blood cell membrane fatty acids are said to reflect dietary fat intake in relation to the biological half life of cells (Romon et al., 1995; Zamaria, 2004). Furthermore, red blood cell membranes, in contrast to other cells, lack the desaturase enzymes and must get their fatty acids preformed from plasma (Allen et al., 2006). Fatty acids may be saturated, monounsaturated (the n-7 and n-9 fatty acid series) or polyunsaturated (the n-3 and n-6 fatty acid series) and membrane fatty acids may further be non-esterified or esterified into glycerophospholipids (Koay & Walmsley, 1999).