The fatty acid pattern of triglycerides in liver, adipose tissue and serum of diabetics with hyperlipoproteinemia before and during clofibrate treatment

Perturbations in the lipid profile of individuals with newly diagnosed type 1 diabetes mellitus: lipidomics analysis of a Diabetes Antibody Standardization Program sample subset

OBJECTIVES

To characterize the lipid profile of individuals with newly diagnosed type 1 diabetes mellitus using LC-MS-based lipidomics and the accurate mass and time (AMT) tag approach.

DESIGN AND METHODS

Lipids were extracted from plasma and sera of 10 subjects from the Diabetes Antibody Standardization Program (years 2000-2005) and 10 non-diabetic subjects and analyzed by capillary liquid chromatography coupled with a hybrid ion-trap-Fourier transform ion cyclotron resonance mass spectrometer. Lipids were identified and quantified using the AMT tag approach.

RESULTS

Five hundred fifty-nine lipid features differentiated (q<0.05) diabetic from healthy individuals in a partial least-squares analysis, characterizing individuals with recently diagnosed type 1 diabetes mellitus.

CONCLUSIONS

A lipid profile associated with newly diagnosed type 1 diabetes may aid in further characterization of biochemical pathways involved in lipid regulation or mobilization.

Serum fatty acid profiles in type I and type II diabetes: metabolic alterations of fatty acids of the main serum lipids

Fatty acid profiles of various lipid fractions were determined in carefully selected insulin-dependent and non-insulin-dependent diabetics to assess relationships between serum fatty acid composition and type of diabetes. Clear-cut hypertriglyceridemia with slight hypercholesterolemia was found in both diabetic types. The decrease of lignoceric acid in sphingomyelin is the only alteration found in both types of diabetes. In the insulin-dependent diabetics, there were increases in levels of oleic acid and of alpha-linolenic acid in esterified cholesterol, and in levels of alpha-linolenic acid in the triglyceride fraction. In the non-insulin-dependent diabetics, there were increases in levels of oleic acid and total monounsaturated fatty acids in the triglyceride fraction and there was an increase in levels of saturated fatty acids and a decrease in levels of polyunsaturated acids in phosphatidylcholine; in sphingomyelin, dihomogamma-linoleic acid levels were enhanced. Arachidonic acid levels were normal in our patient population.

Stress and fatty liver--possible indications for dietary long-chain n-3 fatty acids

The favourable effects of eicosapentaenoic acid (EPA)- and doco-sahexaenoic acid (DHA)-rich diets (marine fish, fish oil) on several risk factors for cardiovascular disease are well established. The present survey describes possible new indications for diets supplemented with long-chain n-3 fatty acids. During a standardized psychophysiological stress test (arithmetic, sentence completion tasks) systolic blood pressure after 2 weeks of diets supplemented with either 60 ml/day of sunflower or linseed oil was significantly decreased. During the sunflower oil-rich diet 45 g/day of linoleic acid (LA) and during the linseed oil-rich period 38 g/day of alpha-linolenic acid (LNA) were ingested. After a 2-week diet supplemented with mackerel (2 cans/day equivalent to 2.2 g/day of EPA and 2.8 g/day of DHA) systolic and diastolic blood pressure within the same test design appeared significantly lower. After a herring diet providing 2 cans/day, equivalent to 1.0 g of EPA and 1.8 g of DHA, the blood pressure-lowering effect was minor. The increase of thromboxane B2 (TxB2) during the stress test failed to occur after the fish diets. The results suggest a stress-protective effect of polyenoic acid-rich diets, which appears most pronounced and dose-related after long-chain n-3 fatty acids. In human liver an increase of fat droplet size in hepatocytes is associated with a decrease of the percentage of EPA in liver triglycerides. A diminution of plasma free fatty acids (FFA) after a mackerel diet might contribute to a depressed synthesis of liver triglycerides.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood pressure- and lipid-lowering effect of mackerel and herring diet in patients with mild essential hypertension

Fourteen male patients with mild essential hypertension were put on a mackerel and herring diet within a prescribed isocaloric regimen in a cross-over design for 2 weeks. After mackerel diet eicosapentaenoic acid (EPA-C20:5, n-3) appeared more in cholesterol esters (1.7-11.0%), whereas docosahexaenoic acid (DHA-C22:6, n-3) was predominantly incorporated into serum triglycerides (1.0-8.3%). After herring diet, which contained half as much EPA and DHA, their increase was of minor degree. After mackerel diet serum triglycerides, total cholesterol, LDL cholesterol and lecithin cholesterol acyl transferase (LCAT) activity were significantly decreased (by 28%, 9%, 14% and 14%, respectively), returning to the initial levels 3 months later. On the contrary, HDL cholesterol appeared significantly increased (by 12%). After herring diet the differences were not significant. Serum sodium was significantly lower (by 2%) at the end of the mackerel diet as compared to the initial values. On the other hand, uric acid in serum appeared transiently increased (by 24%) at the end of both dietary periods. A significant decrease (by 8%) in casual systolic blood pressure, measured in recumbent position, could be observed only at the end of the mackerel period. Moreover, the level of systolic and diastolic blood pressure before and during a standardized psychophysiological stress test was significantly lower after mackerel diet. Nevertheless, the increments after stress were similar. Plasma renin activity was increased (by 64%) after mackerel diet.(ABSTRACT TRUNCATED AT 250 WORDS)

The plasma and erythrocyte fatty acid composition of poorly controlled, insulin-dependent (type I) diabetic patients and the effect of improved metabolic control

Analysis of the plasma and erythrocyte fatty acid composition of poorly controlled, insulin-dependent (type I) diabetic patients revealed a low level of 18:3c, omega 6, 20:3c, omega 6, 22:6c, omega 3 and total polyunsaturated fatty acids, and a high level of 18:0 and total saturated fatty acids. Improvement of diabetic control, achieved by treatment with continuous subcutaneous insulin infusion coincided with an increase of arachidonic acid and a normalization of total polyunsaturated fatty acids, with a concomitant decrease of total saturated fatty acids and total monounsaturated fatty acids, especially 18:1c, omega 9. The results of this study can be important for the dietary advice to poorly controlled, diabetic patients.

Inverse relationship between linoleic acid in serum and in adipose tissue of patients with essential hypertension

In patients with labile essential hypertension without and with overweight as well as in normotensive controls the fatty acid pattern of serum triglycerides and subcutaneous adipose tissue was estimated by gas liquid chromatography. In serum triglycerides of hypertensives linoleic acid was increased but appeared decreased in depot fat. This inverse relationship could not be found for arachidonic acid. Correspondingly, the C 18:2/C 20:4-ratio was higher in serum triglycerides than in adipose tissue. Only in depot fat of overweight hypertensives the percentage of arachidonic acid was decreased when compared to subjects with normal body weight. Linolenic acid remained unchanged in serum triglycerides but decreased significantly in adipose tissue of hypertensive patients. Eicosapentaenoic acid was increased in serum triglycerides and depot fat of patients with essential hypertension of normal body weight. The results are discussed with respect to the possible pathogenesis of essential hypertension and the hypotensive potency of dietary linoleic acid which has been described in patients with high blood pressure.

The fatty acid pattern of triglycerides and FFA in serum of spontaneously hypertensive rats (SHR)

The fatty acid patterns of serum triglycerides and FFA in SHR and in normotensive controls aged 4, 8 and 26 weeks were estimated by gas-liquid chromatography. In serum triglycerides of SHR, the percentage of linoleic acid (C18:2) was lower and the content of arachidonic acid (C20:4) higher than in age-matched control animals. A continuous increase in palmitic (C16) and linoleic acids as well as a decrease in arachidonic acid has been found with advancing age, the most striking differences existing between 4- and 8-week-old animals, i.e. before onset of arterial hypertension in SHR. In the pre-hypertensive stage, the percentage of arachidonic acid was about 3 times as high as in later stages in SHR. This gradation was, however, even more pronounced in normotensive control rats. The C18:2/C20:4-ratio of triglycerides was lower in SHR but increased with age in both groups reaching a 5--8-fold level. Similar behavior of the FFA fatty acid pattern was less marked. Alterations in levels of linoleic and arachidonic acids are of interest because of their pathogenic role as precursors of prostaglandins in the development of genetically spontaneous hypertension in rats. The results are discussed in connection with the hypotensive effect of a linoleic acid-rich diet recently reported in hypertensive rats.