Fatty acid composition of serum and adipose tissue lipids in males with chronic renal failure. Relations to serum lipoproteins and clinical factors

Serum lipids and lipoproteins during continuous ambulatory peritoneal dialysis

The effects of continuous ambulatory peritoneal dialysis (CAPD) on serum lipids and lipoproteins over the initial year of therapy were studied in 23 uremic patients. Lipoprotein abnormalities typical for the uremic dyslipoproteinemia were present at the start of CAPD. During the first months of CAPD these abnormalities were accentuated. The concentrations of very low density lipoprotein (VLDL)-cholesterol (CHOL), low density lipoprotein (LDL)-CHOL, serum CHOL and serum triglycerides (TG) increased significantly. However, after one year of CAPD only the VLDL-CHOL and serum CHOL levels remained significantly higher than the baseline values. VLDL-TG, VLDL-CHOL and serum TG, and the changes of these variables over the study period, correlated with the amount of glucose in the dialysates. We conclude that the continuous peritoneal absorption of glucose (100-200 g/24 h) during CAPD contributes to potentially atherogenic changes in serum lipids and lipoproteins. However, some of the changes are transitory, indicating an adaptation to the peritoneal glucose load.

Plasma and erythrocyte phospholipid fatty acids composition in Serbian hemodialyzed patients

Dyslipidemia is one of the possible risk factors for advanced atherosclerosis in patients with chronic renal failure. Abnormal phospholipid metabolism may play an important role in the progression of atherosclerosis in patients with renal failure. The aim of this study was to determine specific characteristics of plasma and erythrocyte phospholipid content and fatty acid composition in 37 patients with chronic renal failure on hemodialysis (HD). The results were compared with the characteristics of healthy subjects. Briefly, plasma triglyceride (p < 0.001), total cholesterol (p < 0.05), and total phospholipids (p < 0.01) levels were significantly higher and HDL-cholesterol level significantly lower (p < 0.01) in HD patients. Plasma phosphatidylcholine and phosphatidylethanolamine concentration were significantly higher (p < 0.001) in HD patients. The plasma phospholipid fatty acids composition indicated significantly (p < 0.01) higher level of oleic (18:1 n-9) and lower levels of eicopentaenoic (20:5 n-3 EPA) and docosahexaenoic (22:6 n-3 DHA) acids (p < 0.05). However, in HD patients, the relative concentration of plasma phospholipid n-6 polyunsaturated fatty acid (PUFA) was significantly lower (p < 0.05). The fatty acid composition of erythrocyte phospholipid in HD patients was modified with EPA and DHA levels significantly lowered (p < 0.05). Our results demonstrate an abnormal phospholipid metabolism and deficiency of n-3 PUFA in plasma and erythrocyte phospholipids in hemodialyzed patients.

Plasma phospholipid fatty acid pattern in severe liver disease

BACKGROUND/AIMS

In acute liver failure the liver has to regenerate, which may increase the consumption of essential fatty acids. Nutritional support consists mainly of infusion of glucose. It is therefore possible that essential fatty acid deficiency may develop in such patients.

METHODS

Plasma phospholipid composition was studied in healthy controls (n=11), in patients with acute liver failure, (n=10), in patients with stable cirrhosis (n=7), and in patients with acute on chronic liver disease with hepatic encephalopathy (n=6). The influence of 2 days of fat-free diet followed by infusion of glucose was studied in five healthy controls.

RESULTS

The ratio between the sums of nonessential/ essential fatty acids, (n-7+n-9)/(n-3+n-6), was higher in patients with acute liver failure (0.73+/-0.17) compared to healthy controls (0.35+/-0.06, p<0.001). The ratio was also higher in patients with acute on chronic liver disease (1.11+/-0.39) compared to patients with cirrhosis (0.61+/-0.18, p<0.01). These differences were mainly due to low levels of linoleic acid and high levels of oleic acid in the patients with acute liver failure and acute on chronic liver disease. Two days of fat-free diet followed by infusion of glucose did not change this ratio (0.40+/-0.04 vs. 0.47+/-0.05, NS) in healthy controls. The essential fatty acid deficiency indicator eicosatrienoic acid was detectable in 2 out of 11 controls, in 5/10 with acute liver failure, in 7/7 with cirrhosis, and in 6/7 with acute on chronic liver disease.

CONCLUSION

Acute severe deterioration of liver function was associated with changes in the fatty acid composition of plasma phospholipids suggestive of essential fatty acid deficiency.

Red blood cells and platelet membrane fatty acids in non-dialyzed and dialyzed uremics

Three groups of patients with chronic renal failure (CRF), 16 non-dialyzed, 16 undergoing haemodialysis (HD), 16 undergoing continuous ambulatory peritoneal dialysis (CAPD), and 48 controls were examined. We analyzed the fatty acid composition in membranes from erythrocytes and platelets and the platelet malondialdehyde (MDA) production as an index of thromboxane metabolism. Marked differences in erythrocytes fatty acid composition were observed between patients with CRF and controls and, particularly, among the three groups of patients with CRF. Patients on CAPD were characterized by an increase in oleic acid, while haemodialyzed had a marked increase in arachidonic acid. Platelet fatty acid composition showed similar differences, suggesting a 'systemic' membrane abnormality. Platelet MDA was increased in haemodialyzed and positively correlated with the platelet arachidonate content.

Fatty acid composition of adipose tissue and serum micronutrients in relation to common rheumatic complaints in Swedish adults 50-70 years old

Biochemical markers of nutritional status, such as adipose tissue fatty acid composition and circulating levels of micronutrients, may reflect dietary habits, but may also be related to inflammatory activity. We examined the relationship between common rheumatic complaints such as osteo-arthrosis, arthralgia, tendinitis, low-back pain, and neck pain, and the composition of adipose tissue fatty acids, serum concentrations of retinol, ascorbic acid, alpha-tocopherol and selenium in 502, out of 900 randomly selected individuals 50-70 years old. Compared with control subjects the rheumatic group as a whole (p less than 0.01) as well as subgroups like those with arthralgia (p less than 0.01), subacromial shoulder pain (p less than 0.03), and low-back pain (p less than 0.05), had decreased proportions of adipose tissue arachidonic acid. The abnormalities correlated with the duration of the symptom-free period preceding adipose tissue sampling and could not be explained by the evaluation of possible confounding factors. Regarding other fatty acids and micronutrients there were no differences between symptomatic subjects and controls. One explanation for the low proportion of adipose tissue arachidonic acid may be increased eicosanoid production.

Fatty acid induced changes in circulating total and free thyroid hormones: in vivo effects and methodological artefacts

Elevated levels of nonesterified fatty acids (NEFA) are frequently found in acute illnesses, and they may contribute to changes in serum thyroid hormone concentrations in nonthyroidal illnesses (NTI) by displacing protein bound hormones. We therefore examined the effects of low and raised plasma NEFA levels on circulating total and free thyroxine (TT4 and FT4) and triiodothyronine (TT3 and FT3) concentrations, the Free T4 Index (FT4I) and TSH, in a randomized crossover study in 10 normal subjects. Subjects ate either a high carbohydrate breakfast (low NEFA protocol) or a high fat breakfast followed by an iv injection of 1000 u heparin (high NEFA protocol). Possible biological effects of changes in FT4 and FT3 were evaluated by a 200 micrograms iv TRH test. Free T4 and T3 were measured by a direct analogue method (AFT4 and AFT3). In a similar high NEFA study, but without TRH, FT4 was also measured by equilibrium dialysis (DFT4) and a 2-step RIA method (2-step FT4). Acute elevations of plasma NEFA from 0.67 +/- 0.08 mmol/L to a peak of 2.6 +/- 0.54 mmol/L resulted in a prompt reciprocal fall of mean TT4 (-8.7%, p less than 0.01), AFT4 (-30%, p less than 0.005) and TT3 (-11.5%, p less than 0.01) and AFT3 (-16%, p less than 0.005); DFT4 rose significantly from 23.7 +/- 1.9 pmol/L to 33.0 +/- 3.7 pmol/L (+39%, p less than 0.025) and 2-step FT4 rose by 16% (p less than 0.05). TSH levels declined consistently from 3.3 +/- 0.5 mIU/L to 2.6 +/- 0.4 mIU/L (p less than 0.025).(ABSTRACT TRUNCATED AT 250 WORDS)

Serum thyroid hormone binding inhibitor in nonthyroidal illnesses

We have employed the recently developed competitive ligand binding assay (CLBA) to study thyroid hormone binding inhibitor (THBI) in ether extracts of sera of 25 patients admitted to the Medical Intensive Care Unit with a variety of nonthyroidal illnesses (NTI). THBI was detected in 60% (15/25) of patients using one sample/patient and in 88% (15/17) using multiple (two to six) samples from different days. Mortality rate and mean serum concentrations of total T4, total T3, and albumin were similar in THBI-positive and THBI-negative patients. There was a tendency for a higher frequency of low serum total T4 in THBI-positive (10/15) than in THBI-negative (3/10) patients but the difference was not statistically significant (P less than 0.1 by Chi square). However, the mean dialyzable fraction of T4 (DFT4 0.11 +/- 0.02%, n = 9 v 0.054 +/- 0.004%, n = 10) and DFT3 (0.54 +/- 0.05% v 0.40 +/- 0.032%) were both significantly (P less than 0.05) higher in THBI-positive patients than THBI-negative patients. There was a significant correlation between THBI and DFT4 (r = 0.55, P less than 0.02) or DFT3 (r = 0.54, P less than 0.02). Prior extraction of serum with ether reduced DFT4 in NTI patients with high baseline DFT4 but not in normal subjects or NTI patients with mildly abnormal baseline DFT4. Addition to a normal serum (0.1 mL) of evaporated ether extract of a pooled NTI serum (0.10- to 3.0-mL equivalent) increased DFT4 progressively from 0.025% to 0.14%. Similar extract of a pooled serum of normal subjects had little or no effect.(ABSTRACT TRUNCATED AT 250 WORDS)

Relation between consumption of alcohol and fatty acids esterifying serum cholesterol in healthy men

The relation between consumption of alcohol (established by interview), two of its typical markers (gamma-glutamyltransferase activity and mean corpuscular volume), and the composition of fatty acids in plasma cholesterol esters was investigated in an epidemiological study of 1467 actively employed men aged 35-45. In this group of subjects mean consumption of alcohol was 34.6 (SD 25.2) g/day. Palmitoleic acid and oleic acid were positively correlated with consumption of alcohol, gamma-glutamyltransferase activity, and mean corpuscular volume, while linoleic acid was negatively correlated with these variables. When these three fatty acids, gamma-glutamyltransferase activity, mean corpuscular volume, and the fat content of the diet were introduced into a multivariate regression analysis, with consumption of alcohol as the dependent variable, only palmitoleic acid, gamma-glutamyltransferase activity, mean corpuscular volume, and the monounsaturated fat content of the diet remained significant. Palmitoleic acid seems to be an independent correlate of consumption of alcohol and could be useful in epidemiological and clinical studies as a variable of consumption.