Phospholipid Fatty Acid Levels Research Articles

A Cross-Sectional Pilot Study on Association of Ready-to-Eat and Processed Food Intakes with Metabolic Factors, Serum Trans Fat and Phospholipid Fatty Acid Compositions in Healthy Japanese Adults.

Frequently consuming processed and ready-to-eat (RTE) foods is regarded as unhealthy, but evidence on the relationships with circulating metabolic parameters is lacking. Japanese residents of a metropolitan area, 20 to 50 years of age, were studied in terms of anthropometric and biochemical parameters, including circulating trans fat and serum phospholipid fatty acid levels. Processed foods, except drinks and dairy items, were categorized according to requirements for additional ingredients and cooking before eating. Processed and RTE foods were divided according to fat and/or oil content into non-fatty or fatty foods. The participants were grouped into tertiles based on the energy percent (En%) derived from fatty-RTE foods. Fatty-RTE En% showed negative associations with fish, soybean and soybean products, dairy, eggs, vegetables, seaweed/mushrooms/konjac, fruit and non-oily seasonings reflecting lower dietary fiber, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), and mineral and vitamin intakes, while the associations with fat/oil, confectionaries, and sweet beverages were positive. Fatty-RTE En% consumption was positively associated with alkaline phosphatase, leucine aminopeptidase, direct bilirubin, elaidic acid, and C18:2 but inversely associated with HDL cholesterol, C15:0, C17:0, EPA, and DHA. A higher fatty-RTE food intake was suggested to contribute to unbalanced nutrient intakes, as reflected in lipid metabolic parameters. Further large-scale studies are needed to evaluate the quality and impacts of RTE foods.

Circulating plasma phospholipid fatty acid levels as a biomarker of habitual dietary fat intake: The INTERMAP/INTERLIPID Study

Accurate assessment of fat intake is essential to examine relationships between diet and disease risk. However, estimating individual intakes of fat quantity by dietary assessment is difficult. We assessed the association of plasma phospholipid fatty acid levels with dietary intake of fatty acids in the INTERMAP/INTERLIPID study, conducted with a standardized protocol. The study participants were 1339 men and women ages 40-59 years from five Japanese populations one from Hawaii; four from Japan. Fatty acid intake was estimated from four standardized 24-hour dietary recalls. Plasma phospholipid fatty acid composition was analyzed by gas chromatography. We illustrated the relationship between intake and circulating fatty acid levels using Spearman's rank-correlation coefficients, mean, and median values. Spearman's rank-correlation coefficients between intake (g/d) and circulating fatty acid levels (µg/ml) were -0.03 to 0.21 for saturated fatty acids and monounsaturated fatty acids and -0.04 to 0.32 for trans fatty acids. The coefficients for essential n-3 and n-6 fatty acids were moderate to high, especially for eicosapentaenoic acid (EPA), 0.60; docosahexaenoic acid (DHA), 0.41; and EPA+DHA, 0.51. The circulating levels and intake of marine-derived n-3 fatty acids showed a linear association, at least for the intake of EPA+DHA up to 2.1 g/d. We observed high correlation between intake and circulating levels of marine-derived n-3 fatty acids in participants from Japanese and Japanese-American populations with high and low fish intake. Plasma phospholipid marine-derived n-3 fatty acid measurements are a simple and reliable biomarker for assessing dietary intake.

Diversified Effects of COVID-19 as a Consequence of the Differential Metabolism of Phospholipids and Lipid Peroxidation Evaluated in the Plasma of Survivors and Deceased Patients upon Admission to the Hospital.

As a result of SARS-CoV-2 infection, inflammation develops, which promotes oxidative stress, leading to modification of phospholipid metabolism. Therefore, the aim of this study is to compare the effects of COVID-19 on the levels of phospholipid and free polyunsaturated fatty acids (PUFAs) and their metabolites produced in response to reactions with reactive oxygen species (ROS) and enzymes (cyclooxygenases-(COXs) and lipoxygenase-(LOX)) in the plasma of patients who either recovered or passed away within a week of hospitalization. In the plasma of COVID-19 patients, especially of the survivors, the actions of ROS and phospholipase A2 (PLA2) cause a decrease in phospholipid fatty acids level and an increase in free fatty acids (especially arachidonic acid) despite increased COXs and LOX activity. This is accompanied by an increased level in lipid peroxidation products (malondialdehyde and 8-isoprostaglandin F2α) and lipid mediators generated by enzymes. There is also an increase in eicosanoids, both pro-inflammatory as follows: thromboxane B2 and prostaglandin E2, and anti-inflammatory as follows: 15-deoxy-Δ-12,14-prostaglandin J2 and 12-hydroxyeicosatetraenoic acid, as well as endocannabinoids (anandamide-(AEA) and 2-arachidonylglycerol-(2-AG)) observed in the plasma of patients who recovered. Moreover, the expression of tumor necrosis factor α and interleukins (IL-6 and IL-10) is increased in patients who recovered. However, in the group of patients who died, elevated levels of N-oleoylethanolamine and N-palmitoylethanolamine are found. Since lipid mediators may have different functions depending on the onset of pathophysiological processes, a stronger pro-inflammatory response in patients who have recovered may be the result of the defensive response to SARS-CoV-2 in survivors associated with specific changes in the phospholipid metabolism, which could also be considered a prognostic factor.

Circulating plasma phospholipid fatty acid levels and breast cancer risk in the Cancer Prevention Study-II Nutrition Cohort.

Prospective studies that objectively measure circulating levels of fatty acids are needed to clarify their role in the etiology of breast cancer. Thirty-eight phospholipid fatty acids were measured using gas chromatograph in the plasma fraction of blood samples collected prospectively from 2718 postmenopausal women (905 breast cancer cases) enrolled in the Cancer Prevention Study II Nutrition Cohort. Associations of 28 fatty acids that passed quality control metrics (modeled as per 1-SD increase) with breast cancer risk were assessed using multiple variable conditional logistic regression models to compute odds ratios (OR) and 95% confidence intervals (CI). The false discovery rate (q value) was computed to account for multiple comparisons. Myristic acid levels were positively associated with breast cancer risk (OR, 1.17, 95% CI: 1.07-1.28; q value=0.03). Borderline associations were also found for palmitoleic acid (OR, 1.14, 95% CI: 1.04-1.24) and desaturation index16 (OR, 1.10, 95% CI: 1.01-1.20) at nominal P values (<.03) (q values>0.05). These findings suggest that higher circulating levels of myristic acid, sourced from dietary intake of palm kernel oils along with increased de novo synthesis of fatty acids, may increase breast cancer risk. Additional studies are needed to investigate de novo synthesis of fatty acid in breast cancer tissues.

Contributions of biotic and abiotic factors to soil aggregation under different thinning intensities

Soil aggregation is a hierarchical and complex process mediated by both abiotic and biotic factors, and is crucial for preventing erosion.This study aimed to providing new insights into the role of biotic and abiotic factors on soil aggregation amid various thinning intensities and exploring mechanisms of aggregation. A survey involving four thinning treatments (T0: no thinning, T10: low-intensity thinning, T20: medium-intensity thinning, and T50: high-intensity thinning) of Pinus tabulaeformis plantation was conducted to explore mechanisms of soil aggregation and quantify the significance of selected biotic and abiotic factors effects on aggregation using structural equation models. Comprehensive models that included soil physicochemical properties, microbial community, root, and microarthropods were established. Compared to no-thinning, medium-intensity thinning contained about 1.8 times more mean weight diameter (MWD). The levels of total phospholipid fatty acids (totPLFAs), arbuscular mycorrhizal fungi (AMF), mycorrhizal colonization rate (F), and total microarthropods were significantly higher in T20 than in other thinning treatments. The structural equation model indicated that the abiotic, biotic, and abiotic/biotic factors accounted for 35%, 82%, and 92% of the variation on MWD, respectively. MWD depended on the positive influence of F, totPLFAs, and AMF. Microorganisms were positively affected by total microarthropods and negatively affected by Diptera. Overall, the medium-intensity thinning (T20) was beneficial to the stability of soil aggregates. Also, biotic factors were more vital in determining soil aggregation than abiotic factors. Of note, soil microarthropods actd on aggregates by influencing microorganisms rather than directly affecting aggregation.

Exogenous Antioxidants Impact on UV-Induced Changes in Membrane Phospholipids and the Effectiveness of the Endocannabinoid System in Human Skin Cells.

Natural antioxidants effectively counteract changes caused by UV radiation in human skin cells. However, their action is limited due to their lipo/hydrophilicity. Therefore, the aim of this study was to analyze the mutual protective action of hydrophilic ascorbic acid and partially lipophilic rutin against UVA/UVB-induced changes in membranes phospholipid and endocannabinoid system in keratinocytes and fibroblasts. Obtained results clearly showed that, despite the stronger antioxidant properties of ascorbic acid, the lipid membranes were more effectively protected against UV-induced oxidation by rutin, including changes in phospholipid fatty acid levels, prevention against reactive aldehydes formation and endocannabinoids degradation. Ascorbic acid more strongly prevented UV-induced endocannabinoid receptors expression in fibroblasts, especially CB1. However, the combined action of used antioxidants resulted in the greatest cytoprotective effect, which was evident in the inflammatory marker TNFα down-regulation and increased cell viability following cell irradiation. The applied mixture of antioxidants showed a stronger protective in relation to membrane phospholipids in keratinocytes and in the endocannabinoid system in fibroblasts. In conclusion, it can be suggested that combined antioxidant capacities of ascorbic acid and rutin protects against lipid peroxidation but also decreases the UV-induced inflammation by direct interaction with the endocannabinoid system, thus increasing skin cell viability.

Abstract LB079: Circulating plasma phospholipid fatty acid levels &amp; breast cancer risk in the CPS-II Nutrition Cohort

Abstract Circulating plasma phospholipid fatty acid levels and breast cancer risk in the CPS-II Nutrition Cohort Background The association between dietary fat intake and breast cancer risk has been a source of controversy with conflicting results reported in past decades. Additional prospective studies that objectively measure circulating levels of fatty acids are now needed to better understand the associations between dietary fat and breast cancer development. MethodsWe assessed the relation between breast cancer risk and plasma levels of 60 phospholipid fatty acids in a nested case-control study of 2,718 postmenopausal women (905 breast cancer cases and 1,813 matched controls) enrolled in the Cancer Prevention Study II (CPS-II) Nutrition Cohort. Blood samples were collected at baseline (1997-1998). Multivariable-adjusted conditional logistic regression models that included established breast cancer risk factors (alcohol use, postmenopausal hormone use, smoking status, waist circumference, body mass index, and weight change from age 18 years to blood draw) were used to compute odds ratios (OR) and 95% confidence intervals (CI). The false discovery rate (FDR; q-value) was computed to control for multiple comparisons. ResultsAfter adjustment for multiple comparisons and in continuous log-transformed multivariable models, plasma levels of myristic acid (a saturated fatty acid) were positively associated with breast cancer risk (OR per log-value, 1.17, 95% CI: 1.07-1.28; q-value = 0.03), with similar magnitude associations found for estrogen receptor (ER) positive and ER negative breast cancer (p-interaction = 0.39). Positive associations were also found for plasma levels of monounsaturated fatty acid (OR per log-value, 1.09, 95% CI: 1.00-1.18; q-value = 0.24), palmitoleic acid (OR per log-value, 1.14, 95% CI: 1.04-1.24; q-value = 0.09), palmitic acid (OR per log-value, 1.12, 95% CI: 1.01-1.24; q-value = 0.17), dihomo-γ-linolenic acid (OR per log-value, 1.14, 95% CI: 1.04-1.25; q-value = 0.09), and adrenic acid (OR per log-value, 1.13, 95% CI: 1.03-1.24; q-value = 0.11) with breast cancer risk; however, after adjustment for multiple comparisons these associations did not reach the threshold of statistical significance. Similarly, inverse associations between plasma levels of trans α-linolenic acid (OR per log-value, 0.85, 95% CI: 0.76-0.96; q-value = 0.09), heptadecanoic acid (OR per log-value, 0.90, 95% CI: 0.82-0.99; q-value = 0.17), and vaccenic acid (OR per log-value, 0.88, 95% CI: 0.80-0.97; q-value = 0.11) with breast cancer risk were not statistically significant after adjustment for multiple comparisons. ConclusionThese findings suggest that higher circulating levels of myristic acid, that can be sourced from dietary intake of dairy foods or via de novo synthesis, may increase breast cancer risk. Additional studies are needed to replicate this finding and provide mechanistic insights. Citation Format: Michele Matta, Emily Deubler, Veronique Chajès, Marc Gunter, Neil Murphy, Mia M. Gaudet. Circulating plasma phospholipid fatty acid levels &amp; breast cancer risk in the CPS-II Nutrition Cohort [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr LB079.

Using organic fertilizers to increase crop yield, economic growth, and soil quality in a temperate farmland.

We used a constant total N application base rate to conduct a two-year field experiment comparing the effects of three organic fertilizers (rapeseed meal (RSM), soybean meal (SBM), and cattle manure (CM)) on the crop yield, economic growth, and soil quality of a winter wheat-summer maize rotation system. Winter wheat and summer maize in rapeseed meal treatment (RSMT), soybean meal treatment (SBMT), and cattle manure treatment (CMT) showed yield increases of 161%, 299%, and 256%, respectively, when compared to no organic fertilizer treatment (CK) (P < 0.05). The annual net incomes of SBMT and CMT were 1.46 and 1.42 times higher, respectively, than RSMT. Compared to the results of the CK group, RSM, SBM, and CM stimulated the soil physically, chemically, and biologically. We found the highest soil macroaggregate proportions, soil organic matter (SOM) levels, total N (TN) levels, and phospholipid fatty acid (PLFA) levels in SBMT. The highest soil pH, microbial biomass carbon (MBC) levels, and microbial biomass nitrogen (MBN) levels were observed in CMT. We used a soil quality index (SQI) to evaluate soil quality. After the two-year fertilization treatments, we calculated the SQI using a minimum data set (MDS). We used SOM levels and actinomycete quantity for the MDS properties. The SQI values were significantly different across the four treatments, with the highest values occurring in SBMT, then CMT and RSMT. In conclusion, SBM and CM were more effective than RSM at maintaining crop yield, economic growth, and soil quality.

The FAAH Inhibitor URB597 Modulates Lipid Mediators in the Brain of Rats with Spontaneous Hypertension.

Hypertension is accompanied by oxidative stress, which can be modified by the functioning of the endocannabinoid system playing a prominent modulatory role in the brain. The present study tested whether chronic administration of the fatty acid amide hydrolase (FAAH) inhibitor [3-(3-carbamoylphenyl) phenyl]N-cyclohexylcarbamate (URB597) to rats with primary hypertension (SHR) can modify redox balance and consequently brain phospholipid metabolism. Experiments were conducted using SHRs and normotensive control Wistar–Kyoto rats treated by intraperitoneal injection with URB597 for 14 days. The biochemical parameters were assayed in the rats’ brains. Inhibition of FAAH activity by URB597 resulted in an increase in anandamide and GPR55 receptor levels, as well as a decrease in CB2 receptor expression. However, there was a simultaneous increase in Nrf2 expression, as well as Cu, Zn-SOD, GSH-Px, glutathione reductase activity, and vitamin E levels in brain tissue of SHR rats. Consequently, URB597 caused a decrease in levels of phospholipid fatty acids and MDA, and an increase in free fatty acids. Given the importance of maintaining redox balance for brain function, the results of this study point to endocannabinoids as a potential therapeutic target for preventing brain metabolic disorders in hypertension.

Serum Phospholipid Fatty Acids Levels, Anthropometric Variables and Adiposity in Spanish Premenopausal Women.

This study investigates the still uncertain association between serum phospholipid fatty acids (PL-FA), and anthropometric and adiposity variables. A cross-sectional study was conducted with 1443 Spanish premenopausal women. Participants answered an epidemiological and a food frequency questionnaire. Anthropometric variables were measured using a bioimpedance scale. Serum PL-FAs levels were determined by gas chromatography–mass spectrometry. The association between body mass index (BMI), weight gain, body fat percentage, visceral fat index, and waist circumference with serum PL-FAs and desaturation indices was evaluated using multivariable linear regression models. BMI was positively associated with the relative concentration of saturated fatty acids (SFAs) (β = 0.94, q-val = 0.001), and with palmitoleic, dihomo-γ-linolenic (DGLA), arachidonic (AA) and α-linolenic acids, and was inversely associated with oleic, gondoic, trans-vaccenic, linoleic and γ-linolenic acids. Total fat percentage was positively associated with DGLA and AA, and inversely with linoleic and γ-linolenic acids. Low relative concentrations of some SFAs and high levels of n-6 PUFAs were associated with greater waist circumference. While the oleic/stearic and AA/DGLA acid ratios were inversely associated with BMI, DGLA/linoleic acid ratio was positively related to almost all variables. In addition to BMI, total fat percentage and waist circumference were also associated with certain individual fatty acids.

Plasma Phospholipid Fatty Acids, FADS1 and Risk of 15 Cardiovascular Diseases: A Mendelian Randomisation Study.

Whether circulating fatty acids (FAs) play a causal role in the development of cardiovascular disease (CVD) remains unclear. We conducted a Mendelian randomisation study to explore the associations between plasma phospholipid FA levels and 15 CVDs. Summary-level data from the CARDIoGRAMplusC4D, MEGASTROKE, and Atrial Fibrillation consortia and UK Biobank were used. Sixteen single-nucleotide polymorphisms (SNPs) associated with ten plasma FAs were used as instrumental variables. SNPs in or close to the FADS1 gene were associated with most FAs. We performed a secondary analysis of the association between a functional variant (rs174547) in FADS1, which encodes 𝛥5-desaturase (a key enzyme in the endogenous FA synthesis), and CVD. Genetic predisposition to higher plasma α-linolenic, linoleic, and oleic acid levels was associated with lower odds of large-artery stroke and venous thromboembolism, whereas higher arachidonic and stearic acid levels were associated with higher odds of these two CVDs. The associations were driven by SNPs in or close to FADS1. In the secondary analysis, the minor allele of rs174547 in FADS1 was associated with significantly lower odds of any ischemic stroke, large-artery stroke, and venous thromboembolism and showed suggestive evidence of inverse association with coronary artery disease, abdominal aortic aneurysm and aortic valve stenosis. Genetically higher plasma α-linolenic, linoleic, and oleic acid levels are inversely associated with large-artery stroke and venous thromboembolism, whereas arachidonic and stearic acid levels are positively associated with these CVDs. The associations were driven by FADS1, which was also associated with other CVDs.

Plasma phospholipid fatty acids, bone mineral density and fracture risk: Evidence from a Mendelian randomization study.

Available epidemiological evidence on the associations of individual fatty acids (FAs) with bone mineral density and fracture risk is inconsistent and scarce. We conducted a two-sample Mendelian randomization study to explore these relationships. Summary-level data from up to 426824 individuals in UK Biobank for estimated bone mineral density (eBMD) derived from heel quantitative ultrasound and bone fractures were used in this study. Single-nucleotide polymorphisms associated with plasma phospholipid FA levels at genome-wide significance were exploited as instrumental variables. Analyses were conducted using the inverse-variance weighted method. Eight of ten FAs were associated with eBMD and fracture risk. Specifically, genetic predisposition to higher plasma α-linolenic acid, linoleic acid, palmitoleic acid, and oleic acid levels was positively associated with eBMD and inversely associated with the odds of fracture, whereas the opposite directions were observed for plasma arachidonic acid, eicosapentaenoic acid, docosapentanenoic acid, and stearic acid levels. Most of the associations were driven by single-nucleotide polymorphisms within or nearby the FADS1 and FADS2 genes, which explained the largest proportion of variance in FA levels. The associations of arachidonic acid and palmitoleic acid with eBMD remained after exclusion of the variants in the FADS1-FADS2 gene regions. FADS encodes fatty acid desaturases, which have a major role in FA metabolism. Genetic variations in plasma levels of several FAs were associated with eBMD and fracture risk. Variants in FADS1-FADS2 were the major determinants of the observed associations, except the associations of arachidonic acid and palmitoleic acid with eBMD.

Plasma Phospholipid Fatty Acids and Risk of Atrial Fibrillation: A Mendelian Randomization Study.

Available evidence on the associations of dietary and circulating levels of long-chain n-3 fatty acids, which have potential antiarrhythmic properties, and other fatty acids with atrial fibrillation is conflicting and limited. We conducted a Mendelian randomization study to assess the associations between plasma phospholipid fatty acid levels and atrial fibrillation. Summary-level data of atrial fibrillation were available from 65,446 cases and 522,744 non-cases included in the Atrial Fibrillation Consortium. Sixteen single-nucleotide polymorphisms associated with ten fatty acids at significance level of p < 5 × 10−8 were identified as instrumental variables from the hitherto largest genome-wide association studies for plasma fatty acids. The fixed-effects inverse-variance weighted method was used to assess the association of individual plasma fatty acids and atrial fibrillation risk. The random-effects inverse-variance weighted method, weighted median method, and Mendelian randomization (MR)-Egger method were employed as the sensitivity analyses. Genetic predisposition to higher levels of any of the ten individual fatty acids was not associated with atrial fibrillation risk.

Trans-fatty Acids and Survival in Renal Transplantation

High consumption of trans-fatty acids (TFAs) is associated with increased mortality. Observational cohort study of 1.988 Norwegian renal transplant recipients with a median follow-up time of 9.6 years. We assessed multivariable adjusted associations between plasma levels of industrial and ruminant TFAs with patient and graft survival. Plasma phospholipid fatty acid levels were determined by gas chromatography at 10 weeks after transplantation. During follow-up, there were 595 deaths, and 805 grafts were lost. Plasma industrial TFA levels dropped from 0.3 wt% in years 1999-2004 to reach a plateau of 0.2 wt% from year 2005 and beyond, whereas plasma levels of ruminant TFAs remained stable throughout the study period. In the former era (years 1999 to 2004, n=902), we found multivariable adjusted associations between plasma industrial TFA levels and mortality (hazard ratio 4.44, P=.02) and graft loss (hazard ratio 4.22, P=.01). In the latter era (years 2005 to 2011, n=1,086), there were no associations between plasma industrial TFA levels and patient or graft survival. Plasma ruminant TFAs were not associated with mortality or graft loss in either eras. In this Norwegian transplant cohort, plasma industrial TFA levels dropped from around 0.3 wt% in the former era to 0.2 wt% in the latter era. While plasma industrial TFA was significantly associated with survival in the former era, no associations were found with survival in the latter era. This finding suggests that lowering industrial TFA consumption from modest to low levels could possibly influence health beneficially after renal transplantation.

Association between Serum Phospholipid Fatty Acid Levels and Adiposity among Lebanese Adults: A Cross-Sectional Study.

There have been increases in the incidence of obesity in Lebanon over the past few decades. Fatty acid intake and metabolism have been postulated to influence obesity, but few epidemiological studies have been conducted. The aim of this study was to investigate the correlation between serum fatty acid levels and indicators of obesity in a cross-sectional study nested within a cohort of 501 Lebanese adults residing in Greater Beirut. A total of 395 available serum samples (129 men, 266 women) were profiled for phospholipid fatty acid composition. Spearman correlation coefficients adjusted for relevant confounders and corrected for multiple testing were calculated between serum fatty acids, desaturation indices, and indicators of adiposity (body mass index (BMI) and waist). BMI was significantly positively correlated with saturated fatty acids in men (r = 0.40, p < 0.0001, q < 0.0001) and women (r = 0.33, p < 0.0001, q < 0.0001). BMI was significantly positively correlated with monounsaturated fatty acid palmitoleic acid in women (r = 0.15, p = 0.01, q = 0.03). This study suggests that high blood levels of some saturated fatty acids and the monounsaturated fatty acid palmitoleic acid, likely derived from both dietary intakes of saturated fatty acids and endogenous lipogenesis, may have been associated with adiposity in the Lebanese population. The causality of these associations needs to be explored in experimental settings.

Impact of serum cholesterol esterification rates on the development of diabetes mellitus in a general population

sBackgroundLecithin:cholesterol acyltransferase (LCAT) plays an important role in cholesterol esterification in serum. Serum LCAT activity is elevated in patients with serum high triglyceride and low high-density lipoprotein-cholesterol (HDL-C) concentrations, both of which are related to metabolic syndrome and subsequent diabetes mellitus, referred to as lipotoxicity. We hypothesized that increased serum LCAT activity could predict future risk of diabetes mellitus in a general Japanese population.MethodsWe prospectively studied 1496 individuals aged 20–86 years without histories of diabetes mellitus at baseline. Serum lipid concentrations, glucose parameters, and LCAT activity measured as the serum cholesterol esterification rate, were evaluated.ResultsDuring 11 years of follow-up, 46 newly diagnosed patients with diabetes mellitus were reported. After adjustment for plasma glycosylated hemoglobin A1c (HbA1c) levels, the relative risks (RRs) for the development of diabetes mellitus were 5.45 [95% confidence interval (95% CI) 2.37–12.55; P < 0.001] for body-mass index, 0.22 (95% CI, 0.09–0.53; P = 0.001) for HDL-C, 4.81 (95% CI, 1.96–11.77; P = 0.001) for triglyceride, and 4.64 (95% CI, 1.89–11.41; P = 0.001) for LCAT activity. After adjustment for HbA1c, total cholesterol, triglyceride, HDL-C, phospholipid, and free fatty acid levels, the RR of LCAT activity for future risk of diabetes mellitus remained significant (RR, 4.93; 95% CI,1.32–18.41; P = 0.018). In this analysis, we found a significant association between LCAT activity and risk of diabetes mellitus in men but not in women.ConclusionIncreased serum cholesterol esterification rate is a potent predictor for future diabetes mellitus.

Dynamics of soil nitrogen fractions and their relationship with soil microbial communities in two forest species of northern China.

Microbially-mediated soil N mineralization and transformation are crucial to plant growth. However, changes in soil microbial groups and various N components are not clearly understood. To explore the relationship between soil N components and microbial communities, we conducted an in-situ experiment on two typically planted forest species, namely, Sibirica Apricot (SA) and Prunus davidiana Franch (PdF) by using closed-top polyvinyl chloride tubes. Changes in soil inorganic N, organic N (ON) fractions, and levels of microbial phospholipid fatty acids (PLFAs) were measured bimonthly from April 2012 to April 2013. Microbial PLFAs and the concentrations of easily-available microbial biomass N (MBN; ~60 mg kg-1), soluble ON (SON; ~20 mg kg-1), and inorganic N were similar between the two soils whereas the ON (~900 mg kg-1) and its major part total acid-hydrolyzable N (HTN; ~500 mg kg-1), were significantly different (p < 0.05) in most months (5/6 and 4/6; respectively). The canonical correlation analysis of soil N fractions and microbial parameters indicated that the relationship between total PLFAs (total biomass of living cells) and NH4+-N was the most representative. The relative contributions (indicated by the absolute value of canonical coefficient) of NH4+-N were the largest, followed by NO3−-N and MBN. For the HTN component, the relative percentage of hydrolyzable amino acid N and ammonium N decreased markedly in the first half of the year. Canonical variation mainly reflected the relationship between ammonium N and bacterial PLFAs, which were the most sensitive indicators related to soil N changes. The relative contributions of HTN components to the link between soil microbial groups and HTN components were ammonium N > amino acid N > amino sugar N. Observations from our study indicate the sensitivity of soil N mineralization indicators in relation to the temporal variation of soil microbial groups and N fractions.

Development of Kidney Transplant Fibrosis Is Inversely Associated With Plasma Marine Fatty Acid Level

We assessed associations between plasma levels of polyunsaturated fatty acids (PUFAs) and degree of inflammation and interstitial fibrosis in transplanted kidneys. The design of the study was single center cohort study. A study population of 156 patients who received a kidney transplant at Oslo University Hospital during2010. Kidney transplant biopsies were obtained at 2months and 1year after transplantation. Degree of inflammation and interstitial fibrosis in the cortex of transplanted kidneys were estimated semi-quantitatively. Plasma phospholipid fatty acids levels were measured in a stable phase 2months posttransplant. We used multivariate linear regression to assess associations between plasma levels of PUFAs and degree of inflammation and interstitial fibrosis at 2months and 1year postoperatively and change in degree of interstitial fibrosis during the first year after transplantation, adjusting for inflammation and fibrosis risk factors. Higher plasma marine n-3 PUFA levels were associated with less development of interstitial fibrosis in the kidney transplant (unstandardized β-coefficient -1.12, standardized β-coefficient -0.18, P=.03) during the first year after transplantation. Plasma levels of alpha linoleic acid, linoleic acid, and arachidonic acid were not associated with development of interstitial fibrosis. No associations were found between plasma levels of PUFAs and inflammation inside fibrotic areas or outside fibrotic areas in the kidney transplant at neither 2months nor 1year postoperatively. Linolenic acid levels in plasma were positively associated with change in renal function during the first year after transplantation. The inverse association between plasma marine n-3 PUFA levels and development of interstitial fibrosis during the first year after kidney transplantation suggests that marine fatty acid consumption might halt progression of fibrosis.

Decreased soil organic P fraction associated with ectomycorrhizal fungal activity to meet increased P demand under N application in a subtropical forest ecosystem

Phosphorus (P) is an essential but limited nutrient in highly weathered subtropical or tropical forest soils; however, increased P demands owing to elevated nitrogen (N) deposition might further exacerbate the P limitation in these regions. How soil P fractions respond to N enrichment and the underlying mechanisms are not yet understood completely. To address this issue, we conducted an experiment with 3 years of N addition to a Castanopsis carlesii natural forest in Fujian, China; the soil P fractions, microbial biomass, enzyme activities, and phospholipid fatty acid (PLFA) levels were determined. We found that N addition did not significantly alter the microbial biomass C (MBC) and microbial biomass N (MBN), but significantly decreased microbial biomass P (MBP); further, the ratios of MBC:MBP and MBN:MBP increased significantly after N application, indicating that N enrichment enhanced the P demands of plants and soil microorganisms. Moreover, neither resin-P nor NaHCO3-P (extracted by resin and NaHCO3, respectively) was decreased, whereas organic P extracted by NaOH (NaOH-Po) was decreased after N addition, implying that NaOH-Po is a potentially significant source of available P. In particular, appositive correlation between abundance of ectomycorrhizal fungi and NaOH-Po and significant relationships between acid phosphomonoesterase activity (ACP) and labile P contents were noted, suggesting that ectomycorrhizal fungi can play a major role in the depletion of soil organic P, and these enzyme activities can mobilize the unavailable P to labile P in the investigated forest. Taken together, our results revealed a novel mechanism for the maintenance of soil labile P in a subtropical natural forest under chronic stress of N deposition.

Association between serum phospholipid fatty acid levels and adiposity in Mexican women

Fatty acids (FAs) have been postulated to impact adiposity, but few epidemiological studies addressing this hypothesis have been conducted. This study investigated the association between serum phospholipid FAs (S-PLFAs) and indicators of obesity. BMI and waist-to-hip ratio (WHR) were collected from 372 healthy Mexican women included as controls in a case-control study. S-PLFA percentages were determined through gas chromatography. Desaturation indices, SCD-16, SCD-18, FA desaturase (FADS)1, and FADS2, biomarkers of endogenous metabolism, were proxied respectively as 16:1n-7/16:0, 18:1n-9/18:0, 20:4n-6/20:3n-6, and 22:6n-3/20:5n-3. Multiple linear regressions adjusted for relevant confounders and corrected for multiple testing were conducted to determine the association between S-PLFA, desaturation indices, and indicators of adiposity. SCD-16 (β = 0.034, P = 0.001, q = 0.014), palmitoleic acid (β = 0.031, P = 0.001, q = 0.014), and dihomo-γ-linolenic acid (β = 0.043, P = 0.000, q = 0.0002) were positively associated with BMI. Total n-6 PUFAs (β = 1.497, P = 0.047, q = 0.22) and the ratio of n-6/n-3 PUFAs (β = 0.034, P = 0.040, q = 0.19) were positively associated with WHR, while odd-chain FAs (pentadecanoic and heptadecanoic acid) showed negative associations with all the adiposity indicators. In conclusion, increased endogenous synthesis of palmitoleic acid and a high n-6/n-3 ratio are associated with increased adiposity, while odd-chain FAs are associated with decreased adiposity. Further studies are needed to determine the potential causality behind these associations.