The Relation between Insulin Sensitivity and the Fatty-Acid Composition of Skeletal-Muscle Phospholipids

Abstract

Decreased insulin sensitivity is associated with decreased concentrations of polyunsaturated fatty acids in skeletal-muscle phospholipids, raising the possibility that changes in the fatty-acid composition of muscles modulate the action of insulin.

The Pro12Ala polymorphism of the PPAR-γ2 gene affects associations of fish intake and marine n−3 fatty acids with glucose metabolism

“…The mechanisms through which long-chain nÀ3 fatty acids may affect glucose metabolism include their incorporation into the phospholipids of plasma membranes, which increases the fluidity of the membranes and modulates the properties of membrane proteins mediating insulin action (Borkman et al, 1993;Liu et al, 1994;Mori et al, 1997). In the present study, we observed higher plasma EPA in female Ala-allele carriers than in Pro/Pro females.…”

“…Although the controversy in earlier data concerning marine fatty acids and glucose metabolism (Salomaa et al, 1990;Feskens et al, 1991Feskens et al, , 1995Borkman et al, 1993;Adler et al, 1994;Vessby et al, 1994aVessby et al, , b, 2001Pan et al, 1995;Marshall et al, 1997;Baur et al, 1998;Gustafsson et al, 1998;Bjerregaard et al, 2000;Ekblond et al, 2000;Mori et al, 2000;Hu et al, 2001;Salmeró n et al, 2001;Dewailly et al, 2001a, b;van Dam et al, 2002;Wang et al, 2003;Harding et al, 2004;Thorsdottir et al, 2004) may be partly explained by different doses and durations of supplementation in intervention studies, and by different background diets between the study populations, inclusion of subjects with different PPARG Pro12Ala genotypes could also influence the outcome of the study. That PPARG genotype may affect the associations of dietary fat composition with insulin concentrations (Luan et al, 2001) and serum triacylglycerol response to fish oil supplementation (Lindi et al, 2003) was suggested previously.…”

“…Furthermore, it has been observed that Pima Indians, who are at high risk for TIID, have a lower muscle phospholipid DHA level compared to a Caucasian population (Borkman et al, 1993;Pan et al, 1995). This observation has urged the speculations that genetically determined differences in elongation and desaturation of fatty acids or their incorporation into membranes might contribute to the difference (Pan et al, 1995).…”

“…Especially, long-chain nÀ3 polyunsaturated fatty acids have been found to be associated with enhanced glucose metabolism (Feskens et al, 1991;Adler et al, 1994;Feskens et al, 1995;Baur et al, 1998;Ekblond et al, 2000;Hu et al, 2001;Salmeró n et al, 2001;Thorsdottir et al, 2004) and to lower serum free fatty acid (FFA) concentrations (Gustafsson et al, 1998), although there are also contradictory results (Salomaa et al, 1990;Borkman et al, 1993;Vessby et al, 1994aVessby et al, , b, 2001Pan et al, 1995;Marshall et al, 1997;Bjerregaard et al, 2000;Mori et al, 2000;Dewailly et al, 2001a, b;van Dam et al, 2002;Wang et al, 2003;Harding et al, 2004). It is not known whether some of the discrepancies in previous results could be attributed to differences in the genetic background of the subjects.…”

“…A high level of unsaturation of skeletal muscle fatty acid composition has been related to enhanced glucose metabolism (Borkman et al, 1993;Pan et al, 1995;Baur et al, 1998). Since EPA and DHA are formed from the 18-carbon a-linolenic acid (ALNA) through desaturation and carbonchain elongation, the activity of the enzymes involved in the conversion may affect the plasma levels of EPA and DHA.…”