Acid Composition Of Serum Phospholipids Research Articles

The fatty acid composition of serum phospholipids in adolescents is associated with body composition in early adulthoods: an eight-year follow-up study.

The fatty acid composition is associated with obesity. Omega 3 polyunsaturated fatty acid (PUFA) could have a beneficial role in the prevention and treatment of many disorders, including cardiometabolic diseases. A cohort of 84 men and 131 women were examined in adolescence and after 8 years. Body weight (BW) and fat mass (FM) were measured. The composition of fatty acids (FAs) of serum phospholipids was assessed using gas chromatography. Statistics: PLS method. Aim: to determine the relationships between FAs in adolescence and FM (explanatory variable 1, EV1) and BW (explanatory variable 2, EV2) in adulthood. In the predictive models, a cluster of FAs in boys explained 47.2 % of EV1 and a cluster of 6 FAs in girls explained 32.3 % of EV1 measured in adulthood. FAs measured in adolescents explained 23.7 % of EV2 in early adults regardless of gender. A significant negative association was found between 18:1n-9c and EV1 in males and EV2 in both genders. We found a significant negative association between 18:2n-6 and 20:0 and both EV1 and EV2. In all analyses, we found a significant negative association of 20:1n-9 and 18:3n-3 with EV1-2 in both genders. A significant positive association was found in 20:3n-6 with EV1 and EV2 in males. 20:4n-6 was positively associated with EV1 in females and EV2 in both genders. A positive association between FM and very long chain n- 6 PUFAs was also observed. It is concluded that serum MUFAs and essential PUFAs in adolescence are associated with lower BW and FM in adulthood.

Unsaturated fatty acid composition in serum phospholipids in patients in the acute phase of myocardial infarction.

Recent improvements in optimal cardiovascular therapy have questioned the beneficial effects of polyunsaturated fatty acids (PUFAs) observed in previous studies. We investigated the fatty acid (FA) composition in serum phospholipids in patients with an established acute phase of myocardial infarction (MI) and in high‑risk patients with stable atherosclerotic cardiovascular disease (CVD). We studied 83 patients hospitalized within 12 hours from the onset of the first clinical symptoms of MI. As a control group, we assessed 74 patients at high cardiovascular risk with an established stable atherosclerotic CVD treated at an outpatient cardiology clinic. Gas chromatography was used to evaluate the FA composition in serum phospholipids in both groups. The final analysis included 52 patients with acute MI and 74 controls. In both groups, saturated FAs constituted the largest fraction of serum phospholipid FAs (median, 1574.67 μmol/l), followed by n‑6 PUFAs (median, 1106.99 μmol/l). The levels of total saturated FAs, monounsaturated FAs, n‑6 PUFAs, as well as the ratio of n‑6 to n‑3 PUFAs significantly differed between groups. Palmitic acid constituted the largest fraction of serum phospholipids both in patients and controls (31.9% and 31.16%, respectively). In a multivariate logistic regression analysis, body mass index, low‑density lipoprotein cholesterol, aspartate aminotransferase, high‑sensitivity C‑reactive protein, and palmitoleic and eicosadienoic acids were independently associated with MI. We showed major differences in the FA composition of serum phospholipids between patients with acute MI and high‑risk individuals with stable atherosclerotic CVD. Eicosadienoic and palmitoleic acids, apart from typical cardiovascular risk factors, were independently associated with MI.

Relationship between polyunsaturated fatty acid composition in serum phospholipids, systemic low-grade inflammation, and glycemic control in patients with type 2 diabetes and atherosclerotic cardiovascular disease

BackgroundThere are inconsistent data about the role of serum phospholipid fatty acid composition in patients with type 2 diabetes (T2DM) and atherosclerotic cardiovascular disease (ASCVD). The aim of the study was to investigate the relationship between serum phospholipid fatty acid composition, systemic low-grade inflammation, and glycemic control in high-risk T2DM patients.MethodsSeventy-four patients (26% women, mean age 65.6 ± 6.8 years) with T2DM (median diabetes duration 10 years) and documented ASCVD (74 with coronary artery disease, 26 with peripheral arterial disease) were enrolled in the study. Baseline HbA1c was estimated using turbidimetric inhibition immunoassay. According to the median value of HbA1c the patients were grouped into those with HbA1c < 7.0% (< 53 mmol/mol) (n = 38) and those with HbA1c ≥ 7.0% (≥ 53 mmol/mol) (n = 36). Serum phospholipid fatty acids were measured with gas chromatography.ResultsPatients with HbA1c ≥ 7.0%, compared with those with HbA1c < 7.0% had similar composition of saturated and monounsaturated fatty acids in serum phospholipids, but had higher concentrations of linoleic acid (LA) and higher n-6/n-3 polyunsaturated fatty acid (PUFA) ratio as well as lower levels of eicosapentaenoic acid (EPA), total n-3 PUFAs, and the EPA/arachidonic acid ratio. We found that LA (r = 0.25; p = 0.03) and n-6/n-3 PUFA ratio (r = 0.28; p = 0.02) were positively correlated with HbA1c. Multivariate logistic regression analysis showed that n-6/n-3 PUFA ratio, hsCRP and T2DM duration were independent predictors of worse glycemic control in patients with T2DM and ASCVD.ConclusionsThis study showed that glycemic control in high-risk T2DM patients with ASCVD was significantly associated with unfavorable serum phospholipid n-6/n-3 PUFA ratio and greater systemic inflammation.

Effects of a hypoenergetic diet rich in α-linolenic acid on fatty acid composition of serum phospholipids in overweight and obese patients with metabolic syndrome.

Plant-derived α-linolenic acid (ALA) may exert cardioprotective effects. Dietary ALA can undergo desaturation and elongation to form long-chain ω-3 polyunsaturated fatty acids, but the extent to which this occurs in humans is unclear. The aim of the study was to examine the effects of an energy-restricted diet enriched with ALA on fatty acid composition of serum phospholipids in patients with metabolic syndrome. The present analysis compared the effects of a hypoenergetic diet high in ALA (3.4 g/d) with a control diet low in ALA (0.9 g/d) on fatty acid composition of serum phospholipids in 81 overweight or obese patients with features of metabolic syndrome. After a 26-wk intervention, concentration of ALA in serum phospholipids remained constant in both diet groups. The control group had a significant decrease in serum phospholipid eicosapentaenoic acid concentration, although no significant intergroup difference was observed. Serum phospholipid docosahexaenoic acid concentration significantly decreased to a similar extent with both interventions. Additionally, both interventions significantly decreased serum phospholipid concentrations of palmitic acid, stearic acid, total saturated fatty acids, linoleic acid, total ω-6 and ω-3 polyunsaturated fatty acids, with no effect of diet group on these changes. Compared with the ALA diet, the control diet led to a significant increase in serum phospholipid oleic acid concentration. Daily intake of 3.4 g of ALA during a 26-wk energy-restricted diet did not lead to an enrichment of serum phospholipids with ALA and did not increase eicosapentaenoic acid due to conversion. Additionally, dietary ALA was unable to compensate for a decrease in serum phospholipid docosahexaenoic acid.

Effects of the flavonol quercetin and α-linolenic acid on n-3 PUFA status in metabolically healthy men and women: a randomised, double-blinded, placebo-controlled, crossover trial.

Increased dietary intake and tissue status of the long-chain n-3 PUFA, EPA and DHA, is associated with cardiovascular benefits. Epidemiological and animal studies suggest that concomitant nutritive intake of flavonoids may increase the conversion of α-linolenic acid (ALA) to longer-chain n-3 fatty acids EPA and DHA. We investigated the effects of increased ALA intake on fatty acid composition of serum phospholipids and erythrocytes in metabolically healthy men and women and whether fatty acid profiles and ALA conversion were affected by regular quercetin intake or sex. Subjects (n 74) were randomised to receive at least 3·3 g/d ALA with either 190 mg/d quercetin (ALA+quercetin) or placebo (ALA+placebo) in a double-blinded, placebo-controlled, crossover trial with 8-week intervention periods separated by an 8-week washout period. A total of seven subjects dropped out for personal reasons. Data from the remaining sixty-seven subjects (thirty-four males and thirty-three females) were included in the analysis. Both interventions significantly increased serum phospholipid ALA (ALA+placebo: +69·3 %; ALA+quercetin: +55·8 %) and EPA (ALA+placebo: +37·3 %; ALA+quercetin: +25·5 %). ALA + quercetin slightly decreased DHA concentration by 9·3 %. Erythrocyte ALA and EPA significantly increased with both interventions, whereas DHA decreased. Fatty acid composition did not differ between sexes. We found no effect of quercetin. Intake of 3·6 g/d ALA over an 8-week period resulted in increased ALA and EPA, but not DHA, in serum phospholipids and erythrocytes. Neither quercetin supplementation nor sex affected the increment of ALA and relative proportions of n-3 PUFA in serum phospholipids and erythrocytes.

The Effect of Meal Frequency on the Fatty Acid Composition of Serum Phospholipids in Patients with Type 2 Diabetes

Objective: Fatty acids are important cellular constituents that can affect many metabolic processes relevant for the development of diabetes and its complications. We previously demonstrated a positive effect of eating just 2 meals a day, breakfast and lunch, compared to 6 small meals. The aim of this secondary analysis was to explore the effect of meal frequency on the fatty acid composition of serum phospholipids in subjects with type 2 diabetes (T2D).Methods: In a randomized, crossover study, we assigned 54 patients with T2D to follow one of 2 regimens of a hypocaloric diet (−500 kcal/day), each for 12 weeks: 6 meals (A6) or 2 meals a day, breakfast and lunch (B2). The diet in both regimens had the same macronutrient and energy content. The fatty acid composition of serum phospholipids was measured at weeks 0, 12, and 24, using gas liquid chromatography. Insulin sensitivity was derived as an oral glucose insulin sensitivity (OGIS) index.Results: Saturated fatty acids (mainly myristic and palmitic acids) decreased (p < 0.001) and n6 polyunsaturated fatty acids increased (p < 0.001) in response to both regimens but more with B2 (p < 0.001 for both). Monounsaturated fatty acids decreased (p < 0.05) and n3 polyunsaturated fatty acids increased (p < 0.001) in response to both regimens, with no difference between the regimens. An increase in OGIS correlated positively with changes in the proportion of linoleic acid in B2. This correlation remained significant even after adjustment for changes in body mass index (BMI; r = +0.38; p = 0.012).Conclusions: We demonstrated that meal frequency affects the fatty acid composition of serum phospholipids. The B2 regimen had more marked positive effects, with saturated fatty acids and the ratio of saturated to unsaturated fatty acids decreasing more. The increase in linoleic acid could partly explain the insulin-sensitizing effect of B2 in T2D.

Polyunsaturated fatty acids in serum and homocysteine concentrations in Japanese men and women: a cross-sectional study

BackgroundSupplementation studies have suggested a role of n-3 polyunsaturated fatty acids (PUFAs) in homocysteine metabolism, but the evidence is limited and inconsistent among studies that measured blood levels of n-3 and n-6 PUFAs. We examined the association between blood levels of PUFAs and homocysteine in Japanese men and women.MethodsThe subjects were 496 employees (290 men and 206 women) of 2 municipal offices in Japan. Fatty acid composition in serum phospholipids and cholesterol ester (CE) was measured using gas–liquid chromatography. Multiple regression was used to calculate means of homocysteine concentrations according to PUFA tertile with adjustment for potential confounders.ResultsSerum homocysteine concentration decreased with increasing levels of total n-3 PUFA, eicosapentaenoic acid and docosahexaenoic acid (DHA) in serum phospholipids and CE with adjustment for age, sex and workplace. However, only DHA in serum phospholipids remained statistically significant after additional adjustment for other potential confounders including serum folate (P-trend = 0.04). N-6 PUFAs were not significantly associated with homocysteine concentrations.ConclusionsHigher proportion of DHA in serum phospholipids may be associated with lower homocysteine concentrations in Japanese men and women.

Vegetarian diet-induced increase in linoleic acid in serum phospholipids is associated with improved insulin sensitivity in subjects with type 2 diabetes

BACKGROUND AND AIMS:Fatty acids are important cellular constituents that may affect many metabolic processes relevant for the development of diabetes and its complications. We showed previously that vegetarian diet leads to greater increase in metabolic clearance rate of glucose (MCR) than conventional hypocaloric diet. The aim of this secondary analysis was to explore the role of changes in fatty acid composition of serum phospholipids in diet- and exercise-induced changes in MCR in subjects with type 2 diabetes (T2D).METHODS:Subjects with T2D (n=74) were randomly assigned into a vegetarian group (VG, n=37) following vegetarian diet or a control group (CG, n=37) following a conventional diet. Both diets were calorie restricted (−500 kcal day–1). Participants were examined at baseline, 12 weeks of diet intervention and 24 weeks (subsequent 12 weeks of diet were combined with aerobic exercise). The fatty acid composition of serum phospholipids was measured by gas liquid chromatography. MCR was measured by hyperinsulinemic isoglycemic clamp. Visceral fat (VF) was measured by magnetic resonance imaging.RESULTS:Linoleic acid (LA; 18:2n6) increased in VG (P=0.04), whereas it decreased in CG (P=0.04) in response to dietary interventions. It did not change significantly after the addition of exercise in either group (group × time P<0.001). In VG, changes in 18:2n6 correlated positively with changes in MCR (r=+0.22; P=0.04) and negatively with changes in VF (r=−0.43; P=0.01). After adjustment for changes in body mass index, the association between 18:2n6 and MCR was no longer significant. The addition of exercise resulted in greater changes of phospholipid fatty acids composition in VG than in CG.CONCLUSION:We demonstrated that the insulin-sensitizing effect of a vegetarian diet might be related to the increased proportion of LA in serum phospholipids.

Abnormalities in the serum phospholipids fatty acid profile in patients with alcoholic liver cirrhosis - a pilot study

The fatty acid composition of serum phospholipids were analyzed in 20 patients with alcoholic liver cirrhosis (11 with malnutrition and 9 with acceptable nutritional status); 25 healthy age and sex-matched adults were used as controls. Cirrhotic patients showed higher levels of palmitic acid and total saturated fatty acids than healthy subjects. Total n-6 and n-3 polyunsaturated fatty acids (PUFA), and levels of linoleic, dihomo-gama linolenic, arachidonic, and docosahexaenoic acid were significantly lower (p<0.001) in patients with alcoholic cirrhosis compared to healthy controls. Significant changes were also found between patients stratified according to nutritional status. In particular, the sum of n-3 PUFA was significantly lower (p<0.001) and ratio of n-6/n-3 fatty acids was higher (p<0.01) in malnourished patients when compared to the patients with acceptable nutritional status. Furthermore, important changes in the levels of saturated fatty acids, palmitoleic and oleic acid and long-chain PUFA were found in well-nourished patients with alcoholic cirrhosis as well. Our present data confirmed evidence that malnutrition is one of the factors that led to lower levels of polyunsaturated fatty acids in patients with alcoholic liver cirrhosis. PUFA supplementation in the latter needs further investigation.

Comparison of the fatty acid composition of the serum phospholipids of controls, prediabetics and adults with type 2 diabetes.

Although abnormalities in the fatty acid composition of serum and red cell membrane phospholipids of patients with type 2 diabetes are well-documented, lacking are studies of this issue in prediabetic individuals. For this cross-sectional study, we recruited 180 subjects (30-80 years), 56 of whom were normal with regard to glucose control (HbA1c, <5.7%), 61 who had prediabetes (HbA1c, 5.7%-6.4%) and 59 who had type 2 diabetes (HbA1c, >6.5%). Serum phospholipids were isolated and analyzed for fatty acids. Most importantly, the fatty acid compositions of the controls and prediabetic subjects were not different for 19 fatty acids. However, the fatty acid profile of the phospholipids of the patients with diabetes differed from the other two groups; the 14 to 18-carbon saturated fatty acids were decreased by 12%-26% whereas the unsaturated fatty acids 16:1n-7, 18:1n-9, 18:2n-6, 20:3n-6 and 20:4n-6 were increased by 45%-64%. Of note, the docosahexaenoic acid (DHA) status of individuals in all three study groups was remarkably low compared with international values, as indicated by DHA proportions in the 1.62%-2.07% range, and there were no differences between groups. The mean melting point of the phospholipid fatty acids of the diabetic patients (32.2°C) was significantly lower (p < 0.001) than that of the prediabetic subjects (38.1°C) and the controls (39.9°C) which were not different from each other. These observations indicate that the fatty acid changes associated with type 2 diabetes follow the onset of the disease as opposed to being a causative factor of poor glucose control and insulin insensitivity.

Association of fatty acid composition in serum phospholipids with metabolic syndrome and arterial stiffness

Background and aimWe examined the association of fatty acid (FA) composition in serum phospholipids with the features of metabolic syndrome (MetS) and arterial stiffness. MethodsKorean men (n=593, 30–79yrs) were categorized based on the number of MetS risk factors (RFs) and measured for the markers of MetS, serum phospholipid FA composition and brachial-ankle pulse wave velocity (baPWV), an index for the severity of arterial stiffness. ResultsInsulin resistance (HOMA-IR), baPWV, LDL size, and adiponectin were significantly altered corresponding to the number of MetS RFs. The proportions of total monounsaturated FA, palmitoleic acid (16:1), oleic acid (18:1ω-9) and dihomo-γ-linolenic acid (DGLA, 20:3ω-6) in serum phospholipids, and DGLA/linoleic acid (LA) (20:3ω-6/18:2ω-6), deta9-desaturase activity (D9D-16: 16:1/16:0 and D9D-18: 18:1ω-9/18:0) significantly increased corresponding to the number of MetS RFs, but D5D (20:4ω-6/20:3ω-6) decreased. baPWV positively correlated with HOMA-IR, palmitic acid (16:0), oleic acid, D6D (18:3ω-6/18:2ω-6), DGLA/LA and D9D-18, and negatively with adiponectin, LDL size, LA, docosahexaenoic acid (DHA, 22:6ω-3) and D5D. Multiple stepwise regression models revealed that baPWV was significantly influenced by systolic blood pressure, age, body weight, triglyceride and LA in serum phospholipids (R2=0.378). Interestingly, baPWV (1419±1cm/s) and MetS (22%) were highest in individuals with lower proportion of LA (<12.361%) and higher proportion of DGLA (≥1.412%) in serum phospholipid FAs. ConclusionThe features of MetS significantly related to serum phosopholipid FA composition. Particularly, arterial stiffness was associated with LA additively together with DLGA. It may suggest a potential benefit of sufficient amounts of LA in serum or in diet can reduce cardiovascular risk.

Fatty acid composition of serum phospholipids in cystic fibrosis (CF) patients with or without CF related liver disease

In cystic fibrosis (CF), changes in fatty acid (FA) composition of serum phospholipids (PL) and cell membranes can account, in part, for the inflammatory state of the disease. The severity of the genotype is known to correlate with the degree of FA changes. Liver diseases, such as cholestasis and cirrhosis are also known to influence FA status. Until now, there is no data on the influence of CF related liver disease (CFRLD) on the FA status of CF patients. The aim of this study was to evaluate, whether the presence of CFRLD influences FA status. A fasting blood sample for the determination of serum vitamin E and PL-FA composition was collected from 79 CF patients with stable pulmonary disease and under good control in our CF centre. Patients with CFRLD (n=13) were compared to CF patients with the same severity of genotype (n=66) but without CFRLD. The CF patients with CFRLD had lower docosahexaenoic acid (DHA, 22:6n-3) and increased docosatetraenoic acid (22:4n-6). There were no significant differences in the precursors of these FAs. DHA concentration in patients with CFRLD is decreased more substantially compared with their genotype controls. The presence of CFRLD should be taken into account in future FA studies in CF patients.

Correlation Between Serum Phospholipid Fatty Acids and Dietary Intakes Assessed a Few Years Earlier

The fatty acid composition of serum phospholipids has been shown to reflect dietary intakes in the previous weeks or months. However, how serum phospholipids relate to fatty acid intakes over a few years has hardly been examined. We designed a cross-sectional study within the E3N cohort, the French component of the European Prospective Investigation into Cancer and Nutrition in which female participants completed a 208-item diet history questionnaire in 1993–1995 and provided blood samples in 1995–1998. The study included 1,114 women who were free of cancer at the time of blood collection. Serum phospholipid fatty acid composition was assessed by capillary gas chromatography. Partial Spearman correlations adjusted for age and body mass index showed weak to moderate, although statistically significant, positive associations between dietary and serum oleic, linoleic, arachidonic, eicosapentaenoic, and docosahexaenoic acids. Moreover, serum oleic acid was directly associated with olive oil, linoleic acid with sunflower oil, pentadecanoic acid with dairy products, long-chain n-3 fatty acids with fatty fish, and trans-monounsaturated fatty acids with manufactured foods. In conclusion, serum phospholipid pentadecanoic acid, oleic, trans-monounsaturated, and polyunsaturated fatty acids are suitable biomarkers for usual dietary intakes, although the association may weaken as the time lag between dietary assessment and blood collection increases.

Inverse relation between levels of anti-oxidized-LDL antibodies and eicosapentanoic acid (EPA)

Oxidative modification of LDL is thought to play an important role in the development of atherosclerosis. Susceptibility of LDL to peroxidation may partly depend on the compositional characteristics of the antioxidant and fatty acid content. The aim of this study was to examine the association between levels of antibodies to oxidized LDL and the various serum fatty acids in women. A total of 465 women aged 18-65 years were selected randomly from the adult population census of Pizarra, a town in southern Spain. Measurement of anti-oxidized-LDL was done by ELISA and the fatty acid composition of serum phospholipids was determined by GC. The levels of anti-oxidized-LDL antibodies were significantly related with age (r - 0.341, P < 0.001), BMI (r - 0.239, P < 0.001), waist:hip ratio (r - 0.285, P < 0.001), glucose (r - 0.208, P < 0.001), cholesterol (r - 0.243, P < 0.001), LDL-cholesterol (r - 0.185, P = 0.002), EPA (r - 0.159, P = 0.003), DHA (r - 0.121, P = 0.026), and the sum of the serum phospholipid n-3 PUFA (r - 0.141, P = 0.009). Multiple regression analysis showed that the variables that explained the behaviour of the levels of anti-oxidized-LDL antibodies were age (P < 0.001) and the serum phospholipid EPA (P < 0.001). This study showed that the fatty acid composition of serum phospholipids, and especially the percentage of EPA, was inversely related with the levels of anti-oxidized-LDL antibodies.

Serum phospholipid n−3 long-chain polyunsaturated fatty acids and physical and mental health in a population-based survey of New Zealand adolescents and adults

Background: Evidence from observational studies suggests that there is an association between n−3 long-chain polyunsaturated fatty acids and depression; however, this association has yet to be examined in a population-based study.Objective: The objective was to assess whether n−3 long-chain polyunsaturated fatty acids in serum phospholipids are associated with mental and physical well-being.Design: The fatty acid composition of serum phospholipids was measured in 2416 New Zealanders aged ≥15 y who took part in the 1997 National Nutrition Survey. The mental and physical component scores were assessed by using the short-form 36 health questionnaire.Results: After adjustment for a number of covariates, there was a significant positive trend in self-reported physical well-being across the quintiles of eicosapentaenoic acid (P for trend = 0.009) and the ratio of eicosapentaenoic to arachidonic acid (P for trend = 0.012). The differences in the physical component score between the first and fifth quintiles were 2.4 and 2.5 points, respectively. The results showed that neither the proportion of eicosapentaenoic acid nor that of docosahexaenoic acid was associated with the mental component score; however, there was a significant positive trend in mental well-being across the quintiles of the ratio of eicosapentaenoic to arachidonic acid (P for trend = 0.044).Conclusion: The results from this population-based survey of New Zealanders suggest a strong and consistent association between eicosapentaenoic acid in serum phospholipids and self-reported physical well-being; the association with mental well-being is less compelling.

Common genetic variants of the FADS1 FADS2 gene cluster and their reconstructed haplotypes are associated with the fatty acid composition in phospholipids

Fatty acid composition in membranes plays an important role in cellular processes and has shown to be associated with the aetiology of several complex diseases in humans. We report strong associations between variants in the human delta-5 and delta-6 desaturase genes FADS1 FADS2 and fatty acid composition in serum phospholipids. Eighteen polymorphisms located in this gene cluster were genotyped in 727 adults from Erfurt, a German centre of the European Community Respiratory Health Survey. The cluster is located at chromosome 11q12-11q13.1, a region repeatedly found to be linked with atopy and other complex diseases. Polymorphisms and statistically reconstructed haplotypes of FADS1 and the upstream region of FADS2 showed strongest associations with the level of the direct precursor of inflammatory eicosanoids, the n-6 fatty acid arachidonic acid (C20:4n-6), also strong associations with levels of the n-6 fatty acids C18:2n-6, C18:3n-6, C20:2n-6, C20:3n-6, C22:4n-6 and of the n-3 fatty acids C18:3n-3, C20:5n-3 and C22:5n-3 (P-values < 1.0 x 10(-13)). Carriers of the rare alleles of several SNPs and their respective haplotypes had a lower prevalence of allergic rhinitis and atopic eczema. No association was found for total and specific IgE levels.

Associations between the intake of dairy fat and calcium and abdominal obesity.

This study evaluates the association between abdominal obesity and the intake of dairy fat and calcium using information from dietary data and the relative content of the fatty acids 14:0, 15:0, and 17 : 0 in serum phospholipids (PL) and adipose tissue (AT), which are suggested biological markers for dairy fat intake. This study also explores how the associations were affected when under-reporters (URs) were separated from the analyses. Cross-sectional study. In all, 301 healthy 63-y-old men with different degrees of fasting-insulin concentrations. Sagittal abdominal obesity (SAD), dietary intake assessed by a 7-day food registration, and the fatty acid composition in serum PL and AT were measured. URs (n=88) and non-under-reporters (non-URs, n=213) were identified by Goldberg's equation, which compares energy intake with energy expenditure, both expressed as multiples of the basal metabolic rate. The intake of dairy fat, expressed as g/100 g fat, was inversely correlated with SAD; however, this association was only observed in the URs (r=-0.36, P=0.001) and not in the non-URs (r=-0.04, P=0.59). The intake of calcium was inversely correlated with SAD in both groups, although the association was weaker in the non-URs. The intake of dairy fat was related to the relative content of the fatty acids 14:0, 15:0, and 17 : 0 in serum PL and AT (r ranging between 0.32 and 0.55). When these fatty acids were correlated to SAD, inverse associations were seen except for 14:0 in PL (r ranging between -0.17 and -0.29. If there is a true inverse association between the intake of dairy fat and SAD, it remains to explain why this association was not seen in the non-URs. The data gave some indications of an inverse association between SAD and the intake of calcium. The diverse findings observed when the URs and non-URs were separated highlight the question of how to use and interpret dietary data in URs when diet-disease relationships are investigated.

Fatty acid composition of serum phospholipid of premenopausal women and postmenopausal women receiving and not receiving hormone replacement therapy

To compare the fatty acid composition of serum phospholipid of premenopausal women with that of postmenopausal women receiving and not receiving hormone replacement therapy (HRT). Women between the ages of 43 and 70 were recruited for two separate case-comparison studies. Participants were grouped as either premenopausal, postmenopausal receiving HRT, or postmenopausal not receiving HRT. All participants were required to complete a 3-day dietary record before providing a 12-h fasting blood sample. Fatty acid composition of phospholipids and lipid concentrations was determined from serum samples. The postmenopausal women receiving HRT had significantly higher concentrations of palmitic acid (16:0), palmitoleic acid (16:1), and di-homo-gamma-linolenic (20:3n-6) and significantly lower levels of docosapentaenoic acid (22:5n-3) than the other groups in both studies. In addition, the postmenopausal women receiving HRT had lower levels of behenic (22:0), lignoceric (24:0), and nervonic acid (24:1) in comparison with the postmenopausal women not receiving HRT. The results of this study indicate that the fatty acid composition of serum phospholipids in women is influenced by menopausal status and hormone use. These results are of interest because high levels of 20:3n-6 and low levels of docosapentaenoic acid have been associated with increased myocardial infarction plus stroke mortality from cardiovascular disease.

Fatty acid composition of phospholipids and cholesteryl esters in maternal serum in the early puerperium

The fatty acid composition of serum phospholipids (PL) and cholesteryl esters (CE) in 26 healthy pregnant women at the end of term and 1 and 3 days after delivery was analysed in order to determine whether the maternal serum fatty acid composition changes in the early puerperium. The composition of the saturated fatty acids significantly changes in the PL fraction: 16:0 decreased and 18:0 increased. Both 20:4n-6 and 20:5n-3 significantly increased after parturition in serum PL while 22:6n-3 remained constant at the three sampling time points. The sum of HUFA was slightly higher 3 days postpartum compared to the prepartum data. The essential fatty acid index significantly increased after delivery. In the CE fraction too differences occurred during puerperium: 18:2n-6 and 20:4n-6 increased and 18:1n-9 decreased after parturition. The sum of the n-3 fatty acids in CE remained unaltered. The EFA index significantly improved both in PL as in CE after delivery. In conclusion, the previously reported changes in the fatty acid composition of PL and CE during normal pregnancy diminish shortly after delivery. In fact, very soon after delivery the maternal fatty acid composition returns to more normal values.

The fatty acid composition of the serum phospholipids of children with sickle cell disease in Nigeria

The purpose of this study was to determine the fatty acid composition of the serum phospholipids of children with sickle cell disease (SCD) in Nigeria and to compare the relative fluidity of the acyl chains of the serum phospholipids of controls versus the subjects with SCD. It is widely accepted that the fatty acid composition of an individual's serum phospholipids reflects that of their tissue phospholipids. An alteration in the fatty acid composition of membrane phospholipids could affect critical membrane-dependent enzymes and processes (e.g., ion and solute transport, hormone–receptor interactions, signal transduction pathways). We found a significant reduction in the content of polyunsaturated n-3 fatty acids in the phospholipids of subjects with SCD which could result in a reduction of the fluidity of their tissue membranes. Specifically, there was a 40–50% reduction in the proportion of total n-3 fatty acids in subjects with SCD. On the basis of calculated melting points and double bond indices of the acyl chains of the serum phospholipids, the phospholipids of the children with SCD are less fluid relative to those of their healthy counterparts. In addition, we determined that linoleic acid, arachidonic acid, and stearic acid were the major determinants of the fluidity of the acyl chains of the serum phospholipids of the healthy controls and children with SCD.