Changes in plasma fatty acid (FA) composition and desaturase activities are observed in metabolic syndrome (MS). However, whether these changes are a reflection of dietary intakes of fats and FAs is not well established. The current study was aimed at assessing plasma FA composition and desaturase enzyme activities as biomarkers of dietary intakes in subjects with MS. Case control study was done on 41 MS patients and was compared with age matched 45 controls. Dietary intakes, anthropometric and clinical parameters were measured. FA composition was analysed using gas chromatography-flame ionisation detector and desaturase enzyme activities were estimated as ratios of product to precursor FAs. Higher levels of 14:0, 16:0, 16:1, 18:1, D9D-18 activity and lower levels of 18:0 and 18:2 n-6 were seen in MS group when compared to controls (p < 0.05). Strong positive correlations were seen between plasma triglyceride (TG) levels and 14:0, 16:0, 16:1, 18:1, total saturated fatty acid, total monounsaturated fatty acid, and D9D activities, while 18:0, 18:2 n-6 and total polyunsaturated fatty acid were negatively correlated with TG. Positive correlations were seen between plasma 14:0, 18:1 and D9D-18 activity with total energy intake and carbohydrate (CHO) intakes but not with fat intake. Plasma FA profile appears to be a better index of total energy intake and CHO intake than fat intake, suggesting it might be a good reflection of endogenous FA metabolism. Changes in FA composition may therefore serve as an early index of dysregulation of FA metabolism, resulting in increased risk of MS.
Keywords: Delta 9-desaturase; Dietary carbohydrates; Endogenous fatty acid metabolism; Metabolic syndrome; Plasma fatty acids.