Fatty acid composition of serum lipids predicts the development of the metabolic syndrome in men

Abstract

Aims/hypothesis: Types of dietary fat have been related to components of the metabolic syndrome. Serum fatty acid composition mainly reflects dietary fat intake, but also endogenous fatty acid synthesis catalysed by Δ-desaturases. It is not known whether alterations of fatty acid composition or desaturase activities predict metabolic syndrome. Materials and methods: We prospectively evaluated fatty acid composition in serum cholesteryl esters and estimated desaturase activities in 1,558 50-year-old men taking part in a population-based cohort study. The follow-up time was 20 years. StearoylCoA desaturase (SCD-1), Δ6 (D6D) and Δ5 (D5D) desaturases were estimated as precursor to fatty acid ratios. Results: High activity of estimated SCD-1 (odds ratio= 1.29, p<0.05) and D6D (odds ratio=1.35, p<0.05), as well as low estimated D5D activity (odds ratio=0.71, p<0.001) predicted the development of metabolic syndrome (as defined by the National Cholesterol Education Program). The predictive value of D5D activity was independent of lifestyle factors (smoking, BMI and physical activity), whereas the risk associated with higher SCD-1 and D6D activities was mainly explained by obesity. Among those developing metabolic syndrome (119 out of 706) during follow-up, the proportions of fatty acids 14:0, 16:0, 16:1 (n−7), 18:1 (n−9), 18:3 (n−6) and 20:3 (n−6) were increased at baseline, while 18:2 (n−6) was decreased (p<0.05 for all). Conclusions/interpretation: Serum fatty acid composition predicts the long-term development of the metabolic syndrome, and D5D activity may be particularly important in this process. Our results suggest a role of dietary fat quality in the development of metabolic syndrome, but the possibility that altered fatty acid composition, partly secondary to genetic or hormonal factors, should also be considered.

Fatty acid desaturases in human adipose tissue: relationships between gene expression, desaturation indexes and insulin resistance

“…Whether this is the case for human SCD is not clear and both fatty acid ratios have been used in the literature, but not usually concurrently. In contrast to our results, Warensjö et al [9] identified the circulating 16:1/16:0 ratio, but not 18:1/18:0 ratio, as a predictor of the metabolic syndrome. The authors suggested that dietary factors could explain the absent relationship for 18:1/18:0, since the diet is normally high in 18:1, which might attenuate the impact of SCD on this specific ratio.…”

“…Indeed, a high adipose tissue 18:1/18:0 ratio was associated with a threefold risk of being insulin resistant, even after adjusting for waist circumference and plasma triacylglycerol. A recent publication identified obesity as being mainly responsible for explaining the association between higher hepatic SCD activity (as estimated from plasma desaturation indexes) and elevated risk of developing the metabolic syndrome [9]. However, the present findings indicate that the relationship between adipose tissue SCD activity and insulin resistance is at least partly independent of obesity (as shown in both logistic and linear regression models).…”

“…Furthermore, the characteristic fatty acid composition of circulating lipids in insulin-resistant individuals indicates that they have increased SCD and D6D activities and decreased D5D activity [5]. The concept that desaturase activities might affect insulin resistance is supported by a recent study in which estimates of hepatic desaturase activity predicted development of the metabolic syndrome [9]. Importantly, however, these studies have not addressed the role of adipose desaturase activities, an issue that is currently unresolved.…”

Serum fatty acid composition and indices of stearoyl-CoA desaturase activity are associated with systemic inflammation : longitudinal analyses in middle-aged men

“…CRP were positively associated with SCD-1 and the proportion of 18 : 1n-9, and inversely associated with 18 : 2n-6, independently of BMI, smoking, physical activity, alcohol intake, erythrocyte sedimentation rate and insulin resistance. The present results accord with previous findings from this population where a similar FA pattern was related to the metabolic syndrome (7) , insulin resistance (4) and CVD (5,6) .…”

Serum phospholipid and cholesteryl ester fatty acids and estimated desaturase activities are related to overweight and cardiovascular risk factors in adolescents

“…1 Epidemiological studies have shown associations of amount and type of dietary fat intake with the development of chronic disease in adults, including obesity, 2 insulin resistance [3][4][5] and cardiovascular disease (CVD). 6,7 Furthermore, experimental studies in adults demonstrate that changes in the type of dietary fatty acid intake may result in changes in insulin action, 7 lower blood pressure, 8 lower total cholesterol, low-density lipoprotein (LDL)-cholesterol, triglycerides and higher high-density lipoprotein (HDL)-cholesterol.…”