Essential fatty acid metabolism in patients with essential hypertension, diabetes mellitus and coronary heart disease

Mortality and morbidity from coronary heart disease (CHD), diabetes mellitus (DM) and essential hypertension (HTN) are higher in people of South Asian descent than in other groups. There is evidence to believe that essential fatty acids (EFAs) and their metabolites may have a role in the pathobiology of CHD, DM and HTN. Fatty acid analysis of the plasma phospholipid fraction revealed that in CHD the levels of gamma-linolenic acid (GLA), arachidonic acid (AA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are low, in patients with HTN linoleic acid (LA) and AA are low, and in patients with non-insulin dependent diabetes mellitus (NIDDM) and diabetic nephropathy the levels of dihomo-gamma-linolenic acid (DGLA), AA, alapha-linolenic acid (ALA) and DHA are low, all compared to normal controls. These results are interesting since DGLA, AA and EPA form precursors to prostaglandin E₁, (PGE₁), prostacyclin (PGI₂), and PGI₃, which are potent platelet anti-aggregators and vasodilators and can prevent thrombosis and atherosclerosis. Further, the levels of lipid peroxides were found to be high in patients with CHD, HTN, NIDDM and diabetic nephropathy. These results suggest that increased formation of lipid peroxides and an alteration in the metabolism of EFAs are closely associated with CHD, HTN and NIDDM in Indians. Since insulin resistance and hyperinsulinemia and features of obesity, NIDDM, HTN and CHD, diseases that are common in Indians, and as decreased insulin sensitivity is associated with decreased concentrations of polyunsaturated fatty acids (PUFAs) in skeletal muscle phospholipids and, possibly, in the plasma, the possibility is raised that changes in the metabolism of EFAs may have a fundamental role in the pathobiology of these conditions. If this is true, this suggests that supplementation of GLA, DGLA, AA, EPA and/or DHA may be indicated to prevent CHD, HTN and NIDDM in Indians.