Differences In Lipid Concentrations Research Articles

Sexual dimorphisms in longitudinal associations of the blood lipidome with cognitive decline in Alzheimer’s disease

AbstractBackgroundLate‐onset Alzheimer’s disease (AD) is the leading cause of dementia with neither cure nor a clearly understood disease trajectory. Previous studies have shown cross‐sectional and longitudinal associations of the blood lipidome and AD. We previously reported on significant sex differences in the associations of lipids with AD biomarkers and it has been suggested that such sex differences may result in distinct trajectories of AD progression. We performed an association study of sex‐stratified longitudinal lipidomics data with cognitive function to further characterize sexual dimorphisms in lipidomic manifestations of AD.MethodWe used a subset of the Alzheimer’s Disease Neuroimaging Initiative (ADNI) dataset: 1349 individuals (745 males and 604 females) with blood samples and clinical data collected at 10 time points with intervals of 6 to12 months (4145 samples total). We analyzed 749 lipid species measured by quantitative LC‐MS lipidomics profiling (Baker Heart and Diabetes Institute, Melbourne, Australia). We calculated linear mixed models (LMMs) and generalized additive mixed models (GAMMs) to analyze time‐resolved associations between lipids and two composite cognitive scores (ADNI memory and executive function) while adjusting for age, sex (pooled analysis only), BMI, HDL‐C, total cholesterol, copies of APOE ε4, years of education as well as significant medication effects.ResultWe observed a significant difference in lipid concentrations between males and females in line with previous studies, however, these differences were not fully consistent across diagnostic groups. In longitudinal association analyses, we found a substantial fraction of lipid species to have significant sex‐specific associations with cognitive function, which were not observed in the pooled analysis. These lipids were distributed across several lipid classes with enrichment in phosphatidylcholines (PC), phosphatidylethanolamines (PE) and triglycerides (TG). Comparisons between LMMs and GAMMs further indicated that some lipids might have a nonlinear relationship with cognitive trajectories.ConclusionOur results suggest that there are substantial sex differences in longitudinal associations of the blood lipidome with cognitive decline resulting in complex and partially nonlinear relationships. The highlighted lipid pathways can serve as a starting point to better characterize sex‐specific molecular changes linked to cognitive decline in AD.

Prevalence of FH-Causing Variants and Impact on LDL-C Concentration in European, South Asian, and African Ancestry Groups of the UK Biobank-Brief Report.

Familial hypercholesterolemia (FH) is a monogenic disease that causes high low-density lipoprotein cholesterol (LDL-C) and higher risk of premature coronary heart disease. The prevalence of FH-causing variants and their association with LDL-C in non-European populations remains largely unknown. Using DNA diagnosis in a population-based cohort, we aimed to estimate the prevalence of FH across 3 major ancestry groups in the United Kingdom. Principal component analysis was used to distinguish genetic ancestry in UK Biobank participants. Whole exome sequencing data were analyzed to provide a genetic diagnosis of FH. LDL-C concentrations were adjusted for statin use. Principal component analysis distinguished 140 439 European, 4067 South Asian, and 3906 African participants with lipid and whole exome sequencing data. There were significant differences between the 3 groups, including total and LDL-C concentrations, and prevalence and incidence of coronary heart disease. We identified 488, 18, and 15 participants of European, South Asian, and African ancestry carrying a likely pathogenic or pathogenic FH-variant. No statistical difference in the prevalence of an FH-causing variant was observed: 1 out of 288 (95% CI, 1/316-1/264) in European, 1 out of 260 (95% CI, 1/526-1/173) in African, and 1 out of 226 (95% CI, 1/419-1/155) in South Asian. Carriers of an FH-causing variant had significantly higher LDL-C concentration than noncarriers in every ancestry group. There was no difference in median (statin-use adjusted) LDL-C concentration in FH-variant carriers depending on their ancestry background. Self-reported statin use was nonsignificantly highest in FH-variant carriers of South Asian ancestry (55.6%), followed by African (40.0%) and European (33.8%; P=0.15). The prevalence of FH-causing variants in the UK Biobank is similar across the ancestry groups analyzed. Despite overall differences in lipid concentrations, FH-variant carriers across the 3 ancestry groups had similar LDL-C levels. In all ancestry groups, the proportion of FH-variant carriers treated with lipid-lowering therapy should be improved to reduce future risk of premature coronary heart disease.

Contrasting lipid biomarkers in mountain rivers in the Nepal Himalayas: Organic matter characteristics and contribution to the fluvial carbon pool

The Nepal Himalayas is the source of many glacial and spring-fed river systems crisscrossing the mountainous terrain. There is an increasing recognition of small mountain rivers (SMRs) to have a significant combined export of dissolved and particulate organic carbon to the global carbon flux. We analyzed fluvial sediments from two SMRs and compared the results with two large mountain rivers (LMRs) in Nepal. We investigated the organic matter (OM), its compositional variability, and seasonal export using a suite of lipid biomarkers, namely n-alkanes, n-alkanoic acids, n-alkanols, and sterols. The SMRs indicated a similarity in lipid distribution and were affected by a strong seasonal variability. The LMRs showed a distinct contrast in the distribution of lipids in suspended sediments. Bedload sediments in SMRs were derived from diverse sources with weak terrigenous dominance all-year-round compared to the suspended load. Functional lipids (n-alkanoic acids and n-alkanols) were the major constituents in SMR sediments, indicating better preservation. In contrast, n-alkane concentration dominated over other fractions in suspended sediments retrieved from LMRs. The biomarker trends differentiate SMRs from LMRs with lower transformed/degraded OM in SMRs. A common observation was the strong presence of even carbon compounds in short-chain n-alkanes in SMR bedload sediments and their predominance in suspended sediments in LMRs. Such an unusual trend is attributed to specific biomarker sources from the catchment and ongoing processes in fluvial systems. Topsoil colonized by fungal species under moist acidic conditions and autochthonous bacteria contributes to the organic matter pool in shallow SMRs. In LMRs, the contribution from thermally mature sedimentary hydrocarbons and the diagenetic reduction of n-alkanoic acids to n-alkanes are additional contributors to the allochthonous carbon pool. The differences in lipid concentrations, their distribution, seasonality, and the size of rivers suggest differential preservation/degradation of the organic matter pool and their importance in contributing to the carbon budget.

PENGAMBANGAN SISTEM NANOSTRUCTURED LIPID CARRIER (NLC) DAUN Chrysanthemum cinerariifolium (Trev.) Vis DENGAN VARIASI KONSENTRASI LIPID

Ethanol extract 96% of Chrysanthemum cinerariifolium (Trev.) Vis leaves are proven to have anticancer activity. However, these compounds have low solubility in water and fat. To improve the bioavailability of preparations, the development of drug design in the form of Nanostructured Lipid Carrier (NLC) is carried out.The aim this study was to determine the effect of differences in lipid concentration of Monostearin and Oleic Acid in the formulation of the NLC system of Chrysanthemum cinerariifolium (Trev.) Vis leaves, which produced good physicochemical characteristics including organoleptic characteristics, pH, viscosity, particle size, and drug entrapment efficiency. Making is done using the High Shear Homogenization method. Organoleptic tests showed ideal results for the Nanostructured Lipid Carrier (NLC) system, the resulting pH values in formula 1 (7.0 ± 0.12), formula 2 (6.7 ± 0.17) and formula 3 (6.8 ± 0.2)), the viscosity value of formula 1 (55.66 ± 2.84 cPs), formula 2 (28.86 ± 3.91 cPs), and formula 3 (28.57 ± 16.85 cPs). Particle size of formula 1 (5530 ± 320.47 nm), formula 2 (5337 ± 671.44 nm) and formula 3 (4676 ± 2215.75 nm)). The entrapment efficiency value of formula 1 drugs (33.55%), formula 2 (38.77%), formula 3 (83.75%). Based on the characterization result, the best formula was obtained at a lipid concentration of 10%, which was used for the formula of the NLC system of Chrysanthemum cinerariifolium (Trev.) Vis leaves for oral anticancer preparations

Determination of one year stability of lipid plasma profile and comparison of blood collection tubes using UHPSFC/MS and HILIC-UHPLC/MS

Effects of blood collection tubes, the time period, the sample origin, and the method used on the lipidomic profile are investigated by ultrahigh-performance supercritical fluid chromatography - mass spectrometry (UHPSFC/MS) and hydrophilic interaction liquid chromatography ultrahigh-performance liquid chromatography - mass spectrometry (HILIC-UHPLC/MS). Heparin plasma samples have been obtained from 99 healthy volunteers at three time points separated by six-month intervals together with one collection for EDTA plasma and serum. Furthermore, lipid concentrations in heparin plasma collected at two different sites are compared. 171 lipid species from eight lipid classes are quantified with UHPSFC/MS, and 122 lipid species from four lipid classes with HILIC-UHPLC/MS. The accuracy of both methods is monitored by the quantitation error using two internal standards (IS) per individual lipid classes. No significant differences in lipid profiles are observed for different time points and types of collection tubes (heparin plasma, EDTA plasma, and serum). Most pronounced lipid concentration differences are observed for the comparison of NIST SRM 1950 human plasma and mean lipid concentrations of the investigated cohort. Furthermore, differences in lipid concentrations are observed between employed methods (UHPSFC/MS vs. HILIC-UHPLC/MS), which can be compensated by the normalization using NIST SRM 1950 human plasma used as the quality control sample.

Association between altered serum lipids levels on cognitive impairment in the pre-elderly and elderly population of South India

Altered serum lipid levels are linked with varying degrees of cognitive impairment due to various mechanisms. In addition, the prevalence of mild cognitive impairment varies substantially from one region to another. The prevalence of cognitive impairment in relation to altered serum lipid levels on cognitive impairment in the pre-elderly and elderly population is of great importance. Therefore, it is important to characterize the features of mild cognitive impairment with respect to altered lipid profile. This study investigated the association between altered serum lipid levels on cognitive impairment in the pre-elderly and elderly population. The present cross-sectional study was done in 406 pre-elderly and elderly patients. The participants were subjected to demographic data collection followed by Mini-Mental State Examination (MMSE). Participants were classified into two groups: cognitively-normal (n=289) and mild cognitive impairment (117). Fasting serum lipids of the participants was estimated using venous blood samples by standard biochemical techniques. Differences in the lipid concentrations between the two groups were then compared using the Mann-Whitney U test. Significant differences were found in MMSE scores between the cognitively-normal and MCI groups (p<0.05). MCI patients had a significantly lower level of high-density lipoprotein when compared to cognitively-normal participants (p<0.05). In addition, the two groups showed differences in education levels attained. The cognitively-normal group had a greater number of educational years when compared to the MCI group. The study found significant differences in serum lipid concentrations between the cognitively-normal individuals and the mild cognitive impairment group. Future investigations may be needed to explore the effects exerted by lipids on cognitive functions.

Infant Feeding Frequency Impacts Human Milk Composition: A Metabolomic Analysis

Abstract Objectives The nutritional composition of human milk is affected by many factors, including stage of lactation and time of day. Metabolomic profiling of milk provides a biochemical fingerprint of hundreds of metabolites being consumed by the infant, which may help to understand potential factors affecting infant health, growth and nutritional status. We hypothesized that frequency of daily lactations would alter the profile of metabolites and lipids in the milk. Methods Human milk samples from 630 individuals [378 mothers exclusively breast feeding and 252 mothers partially breast feeding (i.e., infant supplemented with formula feeding)] from a single sample (infant aged 3 months) were subjected to biphasic extraction and metabolite profiling performed using two separate untargeted liquid chromatography high resolution mass spectrometry analysis methods (polar metabolites and the lipidome). Results Univariate statistical analysis of the lipidome data matrix revealed considerable differences in lipid concentrations between partial or exclusive feeding. Of the 241 lipids measured in the non-polar extracts, 203 were significantly different between the two groups after multiple testing correction (FDR corrected p-value <0.05). These included 96 triglycerides, 78 phospholipids, 27 sphingomyelins and 2 ceramides, all significantly elevated with exclusive feeding. Of the 320 metabolite features measured in the polar extracts, 69 were significantly different between the two groups, including carnitine and metabolites from the lysine degradation pathway, all reduced with exclusive feeding. Random forest analysis highlighted that overall profiles in both polar metabolite and lipid extracts were more consistent across the exclusive feeding group. Conclusions This study provides insight into effects of feeding frequency on metabolite/lipid profiles, showing impact of possible altered milk synthesis and storage on relative abundances of discrete polar metabolites, with a broad impact on many lipid species. Funding Sources Funded by AgResearch Strategic Science Investment Fund via the New Zealand Ministry of Business, Innovation and Employment.

Increased lipid and lipoprotein concentrations in anorexia nervosa: A systematic review and meta-analysis.

Alterations in blood lipid concentrations in anorexia nervosa (AN) have been reported; however, the extent, mechanism, and normalization with weight restoration remain unknown. We conducted a systematic review and a meta-analysis to evaluate changes in lipid concentrations in acutely-ill AN patients compared with healthy controls (HC) and to examine the effect of partial weight restoration. A systematic literature review and meta-analysis (PROSPERO: CRD42017078014) were conducted for original peer-reviewed articles. Forty-eight studies were eligible for review; 33 for meta-analyses calculating mean differences (MD). Total cholesterol (MD = 22.7 mg/dL, 95% CI = 12.5, 33.0), high-density lipoprotein (HDL; MD = 3.4 mg/dL, CI = 0.3, 7.0), low-density lipoprotein (LDL; MD = 12.2 mg/dL, CI = 4.4, 20.1), triglycerides (TG; MD = 8.1 mg/dL, CI = 1.7, 14.5), and apolipoprotein B (Apo B; MD = 11.8 mg/dL, CI = 2.3, 21.2) were significantly higher in acutely-ill AN than HC. Partially weight-restored AN patients had higher total cholesterol (MD = 14.8 mg/dL, CI = 2.1, 27.5) and LDL (MD = 16.1 mg/dL, CI = 2.3, 30.0). Pre- versus post-weight restoration differences in lipid concentrations did not differ significantly. We report aggregate evidence for elevated lipid concentrations in acutely-ill AN patients compared with HC, some of which persist after partial weight restoration. This could signal an underlying adaptation or dysregulation not fully reversed by weight restoration. Although concentrations differed between AN and HC, most lipid concentrations remained within the reference range and meta-analyses were limited by the number of available studies.

Does CTHRC1 Affect Serum Lipid Profiles in Adults?

PURPOSE: Obesity has become a global public health concern as evidence mounts that it is related to a large variety of life threatening diseases from diabetes to heart disease. The biochemical links between body composition and hypercholesterolemia are a target of ongoing research. The hormone collagen triple helix repeat containing 1 (CTHRC1) has been shown to play an important role in the regulation of body composition in mouse models. This study aimed to compare CTHRC1 and serum lipid panels in human adults. We hypothesized that higher CTHRC1 levels would be associated with both decreased cholesterol and triglycerides (TG). METHODS: This study was done in collaboration with researchers at the University of South Carolina who completed the Energy Balance Study (EBS) on 430 adult subjects age 21-35, with BMI ranging from 20-35. Deidentified baseline plasma samples from the EBS subjects were analyzed with enzymatic calorimetric testing and ELISA to measure lipid panels (total cholesterol, HDL, LDL, triglycerides) and CTHRC1 concentrations respectively. Statistical analysis software was used to compare the data both generally and within clinically accepted subgroups of lipid concentrations. RESULTS: Of the 430 samples from the EBS subjects, 310 contained sufficient plasma for both CTHRC1 and lipid panel testing. No statistically significant difference in lipid concentrations was found between detectable and undetectable CTHRC1 groups (p=0.17-0.99). Stratification of CTHRC1 into undetectable, middle 75% and top 25% also showed no significant difference in lipid concentrations (p=0.32-0.79), nor did stratification of lipid panel components into clinically relevant subgroups (total cholesterol </>200, HDL </>40, LDL </>100, TG </>150, p=0.12-0.94). Lastly, linear regression models showed no correlation between CTHRC1 and lipid concentrations (p=0.21-0.93). CONCLUSION: This study demonstrates no association between CTHRC1 and lipid concentrations in a sample of relatively healthy human adults. Further research is required to better understand the temporal variation of CTHRC1 levels in vivo and thus, better time the collection of samples from subjects. Furthermore, a broader range of body composition among future subjects will help to better generalize data to the adult population.

Colour of subcutaneous adipose tissue and colour and tenderness of the longissimus thoracis et lumborum muscle from Holstein–Friesian, Norwegian RedxHolstein–Friesian and JerseyxHolstein-Friesian cattle slaughtered at two live weights as bulls or steers

Meat quality traits for Holstein–Friesian (HF), Norwegian Red × Holstein–Friesian (NR) and Jersey × Holstein–Friesian (JE) cattle reared to slaughter as two genders (bulls and steers) and 2 slaughter weights (570 kg and 640 kg) were compared. Adipose tissue from JE was more yellow (p&lt;0.05) than HF or NR which were similar. There was no difference between breeds and no breed-related interactions for chemical composition, cook loss or instrumental tenderness of longissimus thoracis et lumborum muscle (LT). When adjusted for differences in lipid concentration, LT from NR-sired animals tended to be less red (p=0.058) and LT from JE-sired animals had a lower hue (p&lt;0.05). Substitution of NR or JE for HF sires in the dairy herd will not have important effects on LT characteristics in the production systems examined but the more yellow carcasses from JE-sired cattle may limit their suitability for markets with a carcass fat colour specification.

EFFECTS OF COEXPOSURE WITH ECHINOSTOMA CAPRONI AND SCHISTOSOMA MANSONI MIRACIDIA ON NEUTRAL AND POLAR LIPIDS OF BIOMPHALARIA GLABRATA AS DETERMINED BY HIGH-PERFORMANCE THIN-LAYER CHROMATOGRAPHY-DENSITOMETRY AND OBSERVATIONS ON SNAIL SURVIVAL AND FECUNDITY

High performance thin-layer chromatography (HPTLC)-densitometry was used to characterize and quantify neutral and polar lipids in Biomphalaria glabrata snails subjected to either Echinostoma caproni and Schistosoma mansoni miracidia coexposure, or single exposure to each of these trematode parasites. Observations on survival and fecundity were made on an unexposed population (2 cultures of 25 snails each); a population exposed exclusively to S. mansoni(2 cultures of 25 snails, each exposed to 6 miracidia per snail); a population exposed exclusively to E. caproni (2 cultures of 25 snails, each exposed to 10 miracidia per snail); and a population exposed to S. mansoni and one week later exposed to E. caproni (2 cultures of 25, each exposed to 10 E. caproni miracidia and 6 S. mansonimiracidia per snail). Each culture contained 800 mL of artificial spring water; snails were maintained at 25 ± 1°C and fed boiled romaine lettuce ad libitum. A sample of each population was necropsied at 2, 4, 6, and 8 weeks post exposure to E. caproni. The digestive-gland gonad complex (DGG) of each snail was extracted in chloroform-methanol for lipid analysis. Lipids were separated on 10 × 20 cm Analtech channeled HPTLC-HLF silica gel plates with a preadsorbent zone. For neutral lipids, the mobile phase and detection reagent used were petroleum ether-diethyl ether-glacial acetic acid (80:20:1) and 5% ethanolic phosphomolybdic acid, respectively. For polar lipids, a chloroform-methanol-deionized water (65:25:4) mobile phase and a 10% cupric sulfate in 8% phosphoric acid detection reagent were used. Quantitative densitometric analysis was performed using a CAMAG TLC Scanner 3 with the tungsten light source set at 610 nm for neutral lipids and the deuterium light source set to 370 nm for polar lipids. Significant differences in lipid concentrations were only observed for the free fatty acids (ANOVA, P<0.0125). Survival of snails declined mainly in the group exposed only to E. caproni miracidia and in the coexposed group. Fecundity (based on egg laying) increased in the group exposed only to E. caproni miracidia, but declined in the other groups.

PP013. Oxidized low density lipoprotein accumulation and the expression of the lectin-like oxLDL receptor (LOX-1) in placental tissue in preeclampsia and healthy controls

Oxidized Low Density Lipoproteins (oxLDL) and its receptor the lectin-like oxLDL receptor 1 (LOX-1) are key players in the development of atherosclerotic cardiovascular diseases. Since preeclampsia is known to share similarities to the pathogenesis of atherosclerosis we hypothesized an increased accumulation of oxLDL and an increased expression of LOX-1 at the materno-fetal and feto-fetal interface within the placental tissue in preeclampsia in comparison to a control group. Second, we analyzed maternal and fetal serum lipid parameters including fetal oxLDL concentration. OxLDL and LOX-1 intensity was determined via immunohistochemistry in placental paraffin sections of 11 women suffering from preeclampsia and compared to 11 gestational age matched preterm deliveries (29th to 36th week of gestation). Ten 'High Power Fields' were chosen randomly by the newCAST software and expression was analyzed via standardized methods by two independent and blinded observers. Maternal and fetal triglycerides, total cholesterol, LDL-cholesterol and HDL-cholesterol were measured by enzymatic colorimetric methods. Fetal oxLDL serum concentration was estimated by ELISA. Statistical examination was carried out by Student's t-test. Skewed variables were log-transformed. oxLDL and LOX-1 was predominantly found to be in villous trophoblast and placental endothelium. No significant differences could be observed in oxLDL expression intensities between preeclampsia and controls. LOX-1 expression tended to be increased in placental trophoblast and endothelium without being statistical significant (Table 1). Fetal triglyceride levels were significantly elevated in preeclampsia compared to controls while maternal triglyceride levels tend to be increased. No other significant differences in lipid concentrations could be observed (Table 2). We could not confirm our initial hypothesis of an accelerated oxLDL accumulation in placental tissue of preeclampsia. Though not statistically significant, placental endothelium seems to be activated in preeclampsia since LOX-1 expression is increased. Moreover, preeclampsia is a condition of dyslipidemia affecting both, maternal and fetal serum with implications for development of cardiovascular diseases in later life.

Influence of iron on fatty acid and sterol composition of marine phytoplankton and copepod consumers

We conducted laboratory experiments to determine the influence of iron on the fatty acid (FA) and sterol composition of the diatom Thalassiosira oceanica, the cryptophyte Rhodomonas salina, the prymnesiophyte Isochrysis galbana, and the copepod Acartia tonsa that fed on these algae. Algal cells were cultured with no added Fe or with Fe added at 100 nmol L−1. Fe‐deficient culture medium resulted in lower growth rates, cell volumes, and photosynthetic efficiencies for all algal species. The total mass of FA per cell was 2.2–3.1 times as high in Fe‐replete cells as in Fe‐deficient cells; on a carbon–normalized basis, the FA concentrations of Fe‐replete algal cells were 1.4–1.5 times as high. Differences were noted between Fe treatments for specific saturated, monounsaturated, and polyunsaturated FAs within each algal species. Total C‐normalized 20:5ω3 + 22:6ω3 concentrations declined 18%, 25%, and 35% in Fe‐deficient T. oceanica, R. salina, and I. galbana, respectively. Across all species, another consistent difference in FA composition between Fe treatments was for 18:4ω3, which had a C‐normalized concentration that was ∼ twofold higher in Fe‐replete algae. No consistent pattern for all algal species was evident for Fe effects on algal sterol concentration and composition, and in response to Fe limitation sterols were conserved more than C and FAs in these cells. Copepods feeding on Fe‐replete and Fe‐deficient algae displayed smaller differences in FA and sterol concentrations than in their algal diets. Differences in lipid concentration and composition between Fe‐replete and Fe‐deficient algae may partly explain the lower egg production rate of copepods fed Fe‐deficient algae.

Ethnic differences in blood lipids and dietary intake between UK children of black African, black Caribbean, South Asian, and white European origin: the Child Heart and Health Study in England (CHASE)

Ischemic heart disease (IHD) rates are lower in UK black Africans and black Caribbeans and higher in South Asians when compared with white Europeans. Ethnic differences in lipid concentrations may play a part in these differences. The objective was to investigate blood lipid and dietary patterns in UK children from different ethnic groups. This was a cross-sectional study in 2026 UK children (including 285 black Africans, 188 black Caribbeans, 534 South Asians, and 512 white Europeans) attending primary schools in London, Birmingham, and Leicester. We measured fasting blood lipid concentrations and collected 24-h dietary recalls. In comparison with white Europeans, black African children had lower total cholesterol (-0.14 mmol/L; 95% CI: -0.25, -0.04 mmol/L), LDL-cholesterol (-0.10 mmol/L; 95% CI: -0.20, -0.01 mmol/L), and triglyceride concentrations (proportional difference: -0.11 mmol/L; 95% CI: -0.16, -0.06 mmol/L); HDL-cholesterol concentrations were similar. Lower saturated fat intakes (-1.4%; 95% CI: -1.9%, -0.9%) explained the differences between total and LDL cholesterol. Black Caribbean children had total, LDL-cholesterol, HDL-cholesterol, and triglyceride concentrations similar to those for white Europeans, with slightly lower saturated fat intakes. South Asian children had total and LDL-cholesterol concentrations similar to those for white Europeans, lower HDL-cholesterol concentrations (-0.7 mmol/L; 95% CI: -0.11, -0.03 mmol/L), and elevated triglyceride concentrations (proportional difference: 0.14 mmol/L; 95% CI: 0.09, 0.20 mmol/L); higher polyunsaturated and monounsaturated fat intakes did not explain these lipid differences. Only black African children had a blood lipid profile and associated dietary pattern likely to protect against future IHD. The loss of historically lower LDL-cholesterol concentrations among UK black Caribbeans and South Asians may have important adverse consequences for future IHD risk in these groups.

Quantification of lipids in human lower limbs using yellow bone marrow as the internal reference: gender-related effects

The main purpose of this study was to determine and compare extra- and intramyocellular (IMCL) lipids content in the calf and thigh muscles of normal male and female volunteers using high-spatial-resolution magnetic resonance spectroscopic imaging (MRSI). The study groups consisted of 10 females and 10 males. The subjects were healthy and normal-weight. Fat (yellow bone marrow) was used as the internal concentration reference. Total fat and IMCL content were computed for all muscles in the slice and for three muscle compartments in the thigh, whereas three muscles and three muscle compartments were evaluated in the calf. To avoid the confounding effects of physical activity and diet, measurements were performed in the same session. A common feature for both genders was that thigh muscles had approximately 2.5 times greater total fat content as compared to muscles of the calf. The mean IMCL level was, however, more than 3 times higher in the calf muscles compared with the thigh. No significant differences in lipid concentrations of correspondent regions of interest were found between genders. The high-spatial-resolution MRSI technique enables a more detailed study of muscle lipid distribution and can therefore improve understanding of muscle lipid metabolism in healthy volunteers and in studies of patients with metabolic disorders.

Temporal variation in protein, carbohydrate, and lipid concentrations in Paramuricea clavata (Anthozoa, Octocorallia): evidence for summer–autumn feeding constraints

Temporal variations in protein, carbohydrate, and lipid levels were studied in a passive suspension feeder, the gorgonian Paramuricea clavata. The samples were collected every month for mature and immature colonies over a three-year period (1997–2000). The relationship between biochemical composition and reproductive output was examined on the basis of the 1998 and 1999 data. In female and male P. clavata colonies, the tissue displayed differences in lipid concentrations only in winter–spring, due to the high lipid levels attained by female colonies in this period. Immature colonies showed significant differences in lipid concentration only with respect to mature females in spring. There were clear seasonal trends in the lipid and carbohydrate levels in P. clavata, with maximum values in winter–spring [male lipid 212±75 SD μg mg−1 of organic matter (OM) and female lipid 274±103 SD μg mg−1 of OM; male and female carbohydrate 68±14 SD μg mg−1 of OM], coinciding with maximum food concentration/quality, and minimum values in summer–autumn (male and female lipid 155±57 SD μg mg−1 of OM; male and female carbohydrate 56±14 SD μg mg−1 of OM), coinciding with low food concentration/quality. The relationship between reproductive output and tissue concentrations of lipids, carbohydrates, and proteins was not straightforward, although there was an evident overlap of the lipid accumulation and the gonadal development. The results of this study show that protein, carbohydrate, and lipid levels may provide a record of episodes in the ecological cycle bearing on the trophic aspects of the target species. The results indicate that information on seasonal biochemical levels may explain benthopelagic coupling processes, provided factors such as natural diet, feeding rates, reproduction, and growth are well understood.

Sex and Age Differences in Lipoprotein Subclasses Measured by Nuclear Magnetic Resonance Spectroscopy: The Framingham Study

The sex differential in coronary heart disease (CHD) risk, which is not explained by male/female differences in lipid and lipoprotein concentrations, narrows with age. We examined whether this differential CHD risk might, in part, be attributable to the sizes of lipoprotein particles or concentrations of lipoprotein subclasses. We analyzed frozen plasma samples from 1574 men and 1692 women from exam cycle 4 (1988-1990) of the Framingham Offspring Study. Nuclear magnetic resonance (NMR) spectroscopy was used to determine the subclass concentrations and mean sizes of VLDL, LDL, and HDL particles. Concentrations of lipids and apolipoproteins were measured by standard chemical methods. In addition to the expected sex differences in concentrations of triglycerides, LDL-cholesterol, and HDL-cholesterol, women also had a lower-risk subclass profile consisting of larger LDL (0.4 nm) and HDL (0.5 nm) particles. The sex difference was most pronounced for HDL, with women having a twofold higher (8 vs 4 micromol/L) concentration of large HDL particles than men. Furthermore, similar to the narrowing of the sex difference in CHD risk with age, the observed male/female difference in HDL particle size also decreased with age. Although lipoprotein particle sizes were highly correlated with lipid and lipoprotein concentrations, the sex differences in the mean sizes of lipoprotein particles persisted (P <0.001) even after adjustment for lipid and lipoprotein concentrations. Women have a less atherogenic subclass profile than men, even after accounting for differences in lipid concentrations.

Hepatic lipid and carbohydrate metabolism in rats fed a commercial mixture of conjugated linoleic acids (Clarinol G-80).

Conjugated linoleic acids (CLAs) exert numerous effects in animal models as well as in humans. Among other things, CLAs decrease plasma lipid levels and bring about hepatic steatosis. The latter effects are attributed to an agonistic action of CLAs on the peroxisome-proliferator-activated receptor family primarily responsible for activating genes involved in lipid metabolism and are related to changes in mRNA levels. Such changes are not necessarily reflected in changes in activity of controlling enzymes. To investigate the effects of CLAs treatment on lipid metabolism, we determined lipid concentrations in plasma, lipoproteins and liver and measured the activity of a number of key enzymes in hepatic lipid metabolism as differences in lipid concentrations should be related to changes in enzyme activities. These variables were determined with the rat as a model. Rats were fed a control diet or a diet containing 1.15% trans-10, cis-12 isomer and 1.11% cis-9, trans-11 isomer as part of a commercial mixture of CLAs. After 2 w the animals were killed, and plasma and liver fractions isolated. Subsequently, lipid concentrations of cholesterol, triacylglycerols and phospholipids were determined in the isolated lipoproteins. In livers homogenates, the concentrations of glycogen, cholesterol, triacylglycerol and phospholipids and the activities of enzymes catalyzing pacesetting steps of metabolism were determined, i. e. acetyl-CoA carboxylase, fatty acid synthase, diacylglycerol acyltransferase, 3-hydroxy- acyl-CoA dehydrogenase, citrate synthase and phosphofructokinase. CLAs induced a lowering of the cholesterol levels in total plasma and in LDL and HDL lipoproteins and of phospholipid concentrations in LDL and HDL. CLAs treatment decreased the hepatic activity of diacylglycerol acyltransferase and had no effect on any of the other enzyme activities. In other studies enhanced specific activities of ACC and FAS were found in livers of mice using the same or similar methods and experimental protocol as in the present study. The lack of effect of CLAs treatment on hepatic key enzymes of fatty acid synthesis and oxidation in Wistar rats questions the use of this strain for studying the mechanism(s) underlying CLA's effects on these parameters. However, in the rat model we observed reduced levels of cholesterol in total plasma and in LDL and HDL. Therefore, some aspects like loss of body fat are better studied in mice; for other aspects like reduction in serum cholesterol level the rat may be the model of choice.

Energy allocation among developmental stages, age groups, and types of Atlantic salmon (Salmo salar) spawners

Relationships between energy density (kJ·100 g–1) and body length (mm), which varied between life-history stages of Atlantic salmon (Salmo salar), were described by power functions. The variation was chiefly caused by differences in lipid concentrations. Energy densities of maturing and rematuring parr were higher than those of similarly aged smolts. Monthly specific growth rate was higher in maturing parr than in salmon at sea. Mature parr males allocated relatively more energy to gonadal development and less to soma development than anadromous males. Spawning expenditure increased from 34 to 53% for 55- to 72-cm-long females. In males, similar losses were from 47 to 49% of their total energy content at river entry. More energy was used in reproduction in a long river than in a short one. Male allocation to gonads relative to soma was highest in the shorter river. Energy allocation pattern varied among developmental stages. Very energy-rich male parr rematured in subsequent years without going to sea; less energy-rich ones smolted and migrated to sea.

Incorporation of Lean Red Meat into a National Cholesterol Education Program Step I Diet: A Long-Term, Randomized Clinical Trial in Free-Living Persons with Hypercholesterolemia

Objective: Clinicians often recommend that intake of all meat, particularly red meat, be reduced in conjunction with a low-fat, low-cholesterol diet to reduce low-density lipoprotein (LDL) cholesterol. This study was designed to determine the long-term effects of lean red meat (beef, veal and pork) compared to lean white meat (poultry and fish) consumption on lipoprotein concentrations in free-living hypercholesterolemic subjects consuming a National Cholesterol Education Program (NCEP) Step I diet.Methods: A randomized, crossover design was utilized. Hypercholesterolemic men and women (LDL cholesterol between 3.37 and 4.92 mmol/L) (triglycerides <3.96 mmol/L) (n = 145) were counseled to consume ≥80% of their 170 g/d meat intake as either lean red meat or lean white meat for two 36-week phases, separated by a four-week washout period of free meat selection. Subjects were instructed to follow an NCEP Step I diet throughout the study.Results: There were no significant differences in lipid concentrations between the lean red meat and lean white meat phases. LDL cholesterol was 4.02 ± 0.04 (SEM) and 4.01 ± 0.04 mmol/L in the white and red phases, respectively; this represented a decrease of ∼2% from baseline concentrations (p < 0.01). Total cholesterol also declined by 1% from baseline (p < 0.05), and high-density lipoprotein (HDL) cholesterol rose over the study period by ∼2% to ∼3% from baseline to reach concentrations of 1.37 ± 0.03 mmol/L and 1.38 ± 0.03 mmol/L in the white and red phases, respectively (p < 0.001). Triglycerides were not altered by treatment.Conclusions: Consumption of lean red meat or lean white meat, as part of an NCEP Step I diet, is similarly effective for reducing LDL cholesterol and elevating HDL cholesterol concentrations in free-living persons with hypercholesterolemia.