Plasma Cholesteryl Ester Fatty Acids Research Articles

Fatty acids in multiple circulating lipid fractions reflects the composition of liver triglycerides in humans

Fatty acids (e.g. 16:1n-7) and desaturase indices (e.g. stearoyl-CoA desaturase, SCD) in plasma cholesteryl esters (CE) and phospholipids (PL) are used as biomarkers of dietary fat quality and lipid metabolism and are associated with disease outcomes. Endogenously produced circulating fatty acids are believed to reflect composition of the liver, yet little data exist to support such relationship. We investigated associations between circulating fatty acids and fatty acids within the liver. Liver biopsies and blood were collected from n=60 patients with non-alcoholic fatty liver disease. Fatty acids in CE, PL and triglycerides (TG) in plasma and liver were analyzed using gas chromatography. Associations were assessed using Spearman rank correlations. Overall, fatty acids and desaturase indices in plasma PL and TG showed moderate-strong correlations with fatty acids and desaturase indices in corresponding lipid fractions in liver. For plasma CE, 16:1n-7 and SCD were correlated with 16:1n-7 and SCD in liver CE. Noteworthy, fatty acids in plasma CE and PL also showed moderate-strong correlations with fatty acids in liver TG (e.g. r=0.82-0.87 for 16:1n-7 and r=0.77 for SCD). We demonstrate that fatty acids in circulating lipid fractions, including CE, TG and PL, reflects the composition of liver TG in humans, suggesting that circulating fatty acids might be useful biomarkers for the fatty acid composition of the liver. As liver tissue is rarely available in cohort studies, our findings could enhance our understanding of plasma fatty acids as markers of hepatic lipid metabolism and their links to metabolic diseases.

Consumption of a diet high in dairy leads to higher 15:0 in cholesteryl esters of healthy people when compared to diets high in meat and grain

Background and aimsA higher dairy product intake has been associated to higher blood concentrations of 15:0 (pentadecanoic acid), 17:0 (margaric acid), and 14:0 (myristic acid). This study investigates whether a diet high in dairy products influences cholesteryl ester fatty acid concentrations of these specific fatty acids (FA). Methods and resultsIn a randomized multiple cross-over study, 13 men and 17 women aged 22 ± 4 years with a BMI of 21.6 ± 2.2 kg/m2 received 3 isocaloric intervention diets (dairy, meat or grain) in random order. For this post-hoc analysis, FA in plasma cholesteryl esters were measured using gas chromatography. We performed a linear mixed model per centered log-ratio transformed FA, adjusting for period, and the interaction between diet and period. Consumed total fat intake per controlled intervention diet was 31.0 ± 0.9 en%/day (dairy), 31.5 ± 0.6 en%/day (meat), and 28.4 ± 1.2 en%/day (grain), respectively. The dairy diet led to higher relative concentrations of 15:0 when compared to diets high in meat and grain, (β; 0.27, 95%CI: 0.18,0.37; p = 1.2 × 10−5, and β: 0.15; 95%CI: 0.06,0.24; p = 1.2 × 10−2, respectively). The dairy diet also led to higher 14:0 when compared to the meat diet (β: 0.34; 95%CI: 0.21,0.46; p = 6.0 × 10−5), but not when compared to the grain diet. 17:0 did not differ between diets. ConclusionThe plasma cholesteryl ester fraction after a diet high in dairy was characterized by higher 15:0 levels. Concentrations of 14:0 were only higher when comparing the FA profile after a diet high in dairy when compared to a diet high in meat. Clinical trial registrationClinicalTrials.gov, NCT01314040.

Plasma Cholesteryl Ester Fatty Acids do not Mediate the Association of Ethnicity with Type 2 Diabetes: Results From the HELIUS Study.

Ethnic minority groups have a higher risk of type 2 diabetes (T2D) than the host population. Our aim is to identify whether plasma cholesteryl ester fatty acids (CEFA) mediate the ethnic differences in type 2 diabetes. We included 202 Dutch, 206 South-Asian Surinamese, 205 African Surinamese, 215 Turkish, and 213 Moroccan origin participants of the HELIUS study (Amsterdam, the Netherlands). Logistic regression is used to determine the associations between plasma CEFA and T2D. Mediation analysis is used to identify whether CEFA contributed to the association between ethnicity and T2D. We adjusted for ethnicity, age, sex, smoking, physical activity, and BMI. Associations between plasma CEFA and T2D were similar across all ethnic groups. Although differences in plasma CEFA across ethnic groups were observed, CEFA did not mediate the differences in T2D prevalence between ethnic groups. Although ethnic differences in plasma CEFA are found and CEFA are associated with T2D, CEFA does not contribute to the difference in T2D prevalence between ethnic groups. If confirmed, this implies that maintenance of the more beneficial CEFA profiles in the non-Dutch ethnic groups may be encouraged to prevent an even higher prevalence of T2D in these groups.

Association of plasma fatty acid composition with plasma irisin levels in normal weight and overweight/obese children.

Irisin has been suggested to protect against overweight. There are no previous data on the association of plasma fatty acid (FA) composition with plasma irisin. We studied the association of FA composition with plasma irisin in normal weight and overweight/obese children. This cross-sectional study included pre-pubertal children (388 normal weight children and 55 overweight/obese children); 6-9 years of age, taking part in the Physical Activity and Nutrition in Children Study. After an overnight fast, we measured plasma FA composition by gas chromatography and plasma irisin levels by enzyme-linked immunosorbent assay. Higher proportion of total monounsaturated fatty acids in plasma cholesteryl esters (CEs) (β = 0.139, P = 0.003) and phospholipids (PLs) (β = 0.147, P = 0.002) and lower proportion of total polyunsaturated fatty acids in plasma CE (β = -0.130, P = 0.006) and PL (β = -0.165, P < 0.001) were associated with higher plasma irisin level in the whole study group. The association of plasma FA composition with plasma irisin level was stronger among overweight/obese children compared to normal weight children. Higher proportion of γ-linolenic acid (β = 0.324, P = 0.017) and lower proportion of linoleic acid (β = -0.397, P = 0.005) in plasma CE were related to higher plasma irisin level among overweight/obese children, indicating the direct association of estimated D6D activity in plasma CE (β = 0.343, P = 0.011) with plasma irisin. Furthermore, higher proportion of oleic acid in plasma CE (β = 0.345, P = 0.012) and PL (β = 0.292, P = 0.033) and higher proportion of adrenic acid (β = 0.366, P = 0.008) and docosapentaenoic acid (β = 0.351, P = 0.010) in plasma PL were associated with higher plasma irisin level among overweight/obese children. Metabolically unfavourable plasma FA profile was associated with higher plasma irisin level especially in overweight/obese children, suggesting that excess body fat might modulate these relationships.

Turkish Heart Study: lipids, lipoproteins, and apolipoproteins.

We examined the plasma lipids, lipoproteins, and selected apolipoproteins in approximately 9,000 men and women from six different regions of Turkey with markedly different diets, ranging from an Aegean coast diet high in olive oil (plasma cholesteryl ester fatty acids enriched in monounsaturated fatty acids) to an inland Anatolian diet high in meat and dairy products (plasma cholesteryl esters enriched in saturated fatty acids). The rural population consuming an olive oil-rich diet had the lowest plasma cholesterol levels (men, 149 mg/dl; women, 150 mg/dl). The urban populations of Istanbul and Adana had higher plasma cholesterol levels (men, 202 and 184 mg/dl, respectively; women, 181 and 190 mg/dl, respectively). Affluent men had the highest cholesterol levels (207 mg/dl). The low density lipoprotein (LDL) cholesterol levels tended to parallel the total cholesterol levels (highest for Istanbul men at 136 mg/dl and lowest for Aegean coast men and women at approximately 100 mg/dl). Strikingly, the Turkish people were found to have very low levels of high density lipoprotein (HDL) cholesterol (HDL-C) (mean values for all six regions: men, 34-38 mg/dl; women, 37-45 mg/dl) and total cholesterol/HDL-C ratios that were high (mean values for all six regions: men, 4.5-5.5; women, 3.9-5.0). The low HDL-C levels appear to be caused, at least in part, by a genetic factor. Triglyceride levels also tended to be high in Turkish men (approximately 120-150 mg/dl) and women (approximately 90-110 mg/dl). Thus, even though the total plasma cholesterol levels are not excessively elevated in comparison to those in other populations, the presence of low HDL-C or low HDL-C coupled with mildly elevated triglyceride levels may represent a significant risk factor for heart disease in the Turkish population. Affluence and higher education were associated with higher cholesterol levels. Lack of physical activity, smoking, and alcohol consumption also tended to be associated with a detrimental lipid profile. Lipoprotein[a] levels were identical among the regions surveyed (mean: 11-15 mg/dl) and displayed the typical distribution with an increased number of individuals with low levels. The 90th percentile value for lipoprotein[a] was about 30 mg/dl for both men and women. Smoking, a major risk factor for heart disease, was very prevalent in the Turkish population, especially in men (50-70% smokers) and women in urban areas (30-40% smokers). Hypertension, defined as a systolic pressure > 140 or a diastolic pressure of > 90 occurred in approximately 17% and 26% of the men and women surveyed, respectively.(ABSTRACT TRUNCATED AT 400 WORDS)

Platelet Aggregation in Finnish Men and Its Relation to Fatty Acids in Platelets, Plasma and Adipose Tissue

Platelet aggregation and its relation to fatty acid composition of platelets, plasma and adipose tissue was determined in 196 randomly selected, free-living, 40-49-year-old men in two regions of Finland (east and southwest) with a nearly twofold difference in the IHD rate. There were no significant east-southwest differences in platelet aggregation induced with ADP, thrombin or epinephrine. ADP-induced platelet secondary aggregation showed significant negative associations with all C20-C22 omega 3-fatty acids in platelets (r = -0.26- -0.40) and with the platelet 20: 5 omega 3/20: 4 omega 6 and omega 3/omega 6 ratios, but significant positive correlations with the contents of 18:2 in adipose tissue (r = 0.20) and plasma triglycerides (TG) (r = 0.29). Epinephrine-induced aggregation correlated negatively with 20: 5 omega 3 in plasma cholesteryl esters (CE) (r = -0.23) and TG (r = -0.29), and positively with the total percentage of saturated fatty acids in platelets (r = 0.33), but had no significant correlations with any of the omega 6-fatty acids. Thrombin-induced aggregation correlated negatively with the omega 3/6 omega ratio in adipose tissue (r = -0.25) and the 20: 3 omega 6/20: 4 omega 6 ratio in plasma CE (r = -0.27) and free fatty acids (FFA) (r = -0.23), and positively with adipose tissue 18:2 (r = 0.23) and 20:4 omega 6 (r = 0.22) in plasma phospholipids (PL). The percentages of prostanoid precursors in platelet lipids, i.e. 20:3 omega 6, 20:4 omega 6 and 20:5 omega 3, correlated best with the same fatty acids in plasma CE (r = 0.32 - 0.77) and PL (r = 0.28 - 0.74). Platelet 20:5 omega 3 had highly significant negative correlations with the percentage of 18:2 in adipose tissue and all plasma lipid fractions (r = -0.35 - -0.44).(ABSTRACT TRUNCATED AT 250 WORDS)

Plasma cholesteryl ester fatty acids in 3- and 12-year-old finnish children

Risk factors associated with coronary heart disease were surveyed in a multicentre study carried out in 1979 among children living in different parts of Finland. The survey included analyses of plasma lipids and cholesteryl ester (CE) fatty acids as well as a dietary interview by a 48-hour recall method. The present report gives the plasma fatty acid compositions obtained from 181 3-year-old and 226 12-year-old children and their relations to dietary factors and other plasma lipids. The mean percentages (±SD) of CE linoleate in the 3- and 12-year-old children were 49.2 ± 5.2 and 51.0 ± 5.0%, respectively. Differences in CE fatty acid composition between the various regions of Finland were relatively small, but there was a trend to higher proportions of polyunsaturated fatty acids in western and urban compared with eastern and rural communities. Among different dietary constituents the daily intake of margarine + oils or butter had the greatest effect on plasma CE fatty acid composition. There was a highly significant positive correlation between the dietary P/S ratio and the percentage of CE linoleate in plasma.

Adiposity, lipids, alcohol consumption, smoking, and gender

Indices of obesity, plasma lipids, and lipoprotein levels, plasma cholesteryl ester fatty acid composition, reported alcohol consumption and smoking habits were measured in 88 men and 87 women, ages over 15 years, randomly selected from the total respondents (1192) to a health survey. Most indices of obesity were related to plasma triglycerides and high-density lipoprotein levels in both sexes; to very low-density lipoprotein levels in men only; and to plasma cholesteryl ester fatty acid linoleic acid proportions in women only. The correlations with high-density lipoprotein cholesterol levels were dependent on very low-density lipoprotein triglyceride levels in men but not in women. Indices of obesity were significantly higher in nonsmoking women and reported alcohol consumption correlated with Quetelet's index (body mass index) in men. Smoking habits, but not alcohol consumption, influenced correlations between indices of obesity and plasma triglycerides and very low-density lipoprotein triglyceride levels in men. The present results showed several sex-related differences in relationships with indices of obesity. Lower very low-density lipoprotein levels, higher skinfold measurements, higher cholesteryl ester fatty acid linoleic acid proportions and lower alcohol intake in women than in men may be responsible. The data suggested that in women, altered diet composition may be linked with obesity.

Abnormal fatty acid composition and human atherosclerosis.

Summary Eighty patients with aorto-iliac / femoro-popliteal atherosclerosis were collected to examine in detail their plasma cholesteryl ester fatty acid compositions and to compare them with the incidence of ischaemic heart disease through a 4-year follow-up. Various other biochemical and rheological parameters were also measured to see if these might explain any association between the abnormal fatty acid pattern and ischaemic heart disease. The abnormal fatty acid pattern was specifically and generally similar to that found in essential fatty acid (EFA) deficient animals and children as shown by the increase of the specific trienoic acid (C.20: 3ω9) by reduced linoleic acid concentrations, and by an increase of C.18 and C.16 monoenoic acids (oleic and palmitoleic), but not of their corresponding saturated forms, stearic and palmitic. The results suggest that the abnormal fatty acid composition resulted from an increased synthesis of monoenoic acids and monounsaturase activity, coupled with a relative inadequacy of linoleic acid. The patients with a reduced concentration of linoleic acid (&amp;lt;35%) subsequently had a higher incidence of myocardial infarction. No significant correlations were found between the fatty acid concentration and various other biochemical or rheological parameters except marginally between linoleic acid and platelet adhesiveness. Only the linoleic acid concentration distinguished between the patients with and without myocardial infarction. A marked inverse correlation was found, however, between the monoenoic and linoleic acid concentration, without parallel changes in other fatty acids. It seems that as in animals, a balance exists between EFA and monoenoic pathways which are known to compete for the same desaturase systems and acyl sites. It appears that human EFA requirements and effects need to be considered not only by their intake and metabolism, but also through individual factors which vary the monoenoic concentrations and monounsaturase activity. Since these factors include several currently associated with human atherosclerosis the question arises of whether the EFA-monoenoic balance is one link between them and the pathology of the arterial occlusions and myocardial infarction.