Association between habitual dietary intake and lipoprotein subclass profile in healthy young adults

Exhaustive Search of Dietary Intake Biomarkers as Objective Tools for Personalized Nutrimetabolomics and Precision Nutrition Implementation

OBJECTIVE

To conduct an exhaustive scoping search of existing literature, incorporating diverse bibliographic sources to elucidate the relationships between metabolite biomarkers in human fluids and dietary intake.

BACKGROUND

The search for biomarkers linked to specific dietary food intake holds immense significance for precision health and nutrition research. Using objective methods to track food consumption through metabolites offers a more accurate way to provide dietary advice and prescriptions on healthy dietary patterns by healthcare professionals. An extensive investigation was conducted on biomarkers associated with the consumption of several food groups and consumption patterns. Evidence is integrated from observational studies, systematic reviews, and meta-analyses to achieve precision nutrition and metabolism personalization.

METHODS

Tailored search strategies were applied across databases and gray literature, yielding 158 primary research articles that met strict inclusion criteria. The collected data underwent rigorous analysis using STATA and Python tools. Biomarker-food associations were categorized into 5 groups: cereals and grains, dairy products, protein-rich foods, plant-based foods, and a miscellaneous group. Specific cutoff points (≥3 or ≥4 bibliographic appearances) were established to identify reliable biomarkers indicative of dietary consumption.

RESULTS

Key metabolites in plasma, serum, and urine revealed intake from different food groups. For cereals and grains, 3-(3,5-dihydroxyphenyl) propanoic acid glucuronide and 3,5-dihydroxybenzoic acid were significant. Omega-3 fatty acids and specific amino acids showcased dairy and protein foods consumption. Nuts and seafood were linked to hypaphorine and trimethylamine N-oxide. The miscellaneous group featured compounds like theobromine, 7-methylxanthine, caffeine, quinic acid, paraxanthine, and theophylline associated with coffee intake.

CONCLUSIONS

Data collected from this research demonstrate potential for incorporating precision nutrition into clinical settings and nutritional advice based on accurate estimation of food intake. By customizing dietary recommendations based on individualized metabolic profiles, this approach could significantly improve personalized food consumption health prescriptions and support integrating multiple nutritional data.This article is part of a Nutrition Reviews special collection on Precision Nutrition.

Suboptimal dietary patterns are associated with accelerated biological aging in young adulthood: A study with twins

BACKGROUND & AIMS

Suboptimal diets increase morbidity and mortality risk. Epigenetic clocks are algorithms that can assess health and lifespan, even at a young age, before clinical manifestations of diseases. We investigated the association between dietary patterns and biological aging in young adult twins.

METHODS

The data were drawn from the population-based FinnTwin12 study and consisted of twins aged 21-25 years (n = 826). Food and beverage intakes were assessed using a food frequency questionnaire. Biological aging was estimated using the epigenetic clocks GrimAge and DunedinPACE. Latent class analysis was used to identify dietary patterns. The association between dietary patterns and biological aging was assessed using linear regression modeling at the individual level, followed by within-twin pair analyses to account for genetic liabilities and shared familial confounders.

RESULTS

Six dietary patterns were identified: 1) High fast food, low fruits and vegetables (F&V), 2) Plant-based, 3) Health-conscious, 4) Western with infrequent fish, 5) Western with regular fish, and 6) Balanced average. At the individual level, GrimAge acceleration was slower in the Plant-based, Health-conscious, and Balanced-average patterns compared to the High fast food, low F&V, and faster in the Western with infrequent fish pattern compared to the Balanced average, regardless of sex, nonalcoholic energy intake, smoking, and alcohol consumption. After further adjustment for BMI and sports participation, the strengths of the associations modestly decreased; however, the difference between the Balanced-average and High fast food, low F&V patterns remained significant. The pace of aging (DunedinPACE) was slower in the Plant-based pattern compared to the High fast food, low F&V and the Western with infrequent fish patterns after adjustment for sex, nonalcoholic energy intake, smoking, and alcohol. The effect sizes were attenuated and reached a non-significant level when BMI and sports participation were added to the model. Most of the associations were replicated in the within-pair analyses among all twin pairs and among dizygotic twin pairs, but the effect sizes tended to be smaller among monozygotic twin pairs. This suggests that genetics, but not a shared environment, may partially explain the observed associations between diet and biological aging.

CONCLUSION

Diets high in fast food, processed red meat, and sugar-sweetened beverages and low in fruits and vegetables are associated with accelerated biological aging in young adulthood. The clustering effect of lifestyle factors and genetic confounders should be considered when interpreting the findings.

Association of ultra-processed food-related metabolites with selected biochemical markers in the UK Biobank

BACKGROUND

Ultra-processed food (UPF) intake is positively associated with multiple adverse health outcomes. However, the underlying biological mechanisms remain unclear. Serum metabolites may elucidate these mechanisms. We investigated serum metabolites correlated with UPF and un/minimally processed food (UNPF) intake and evaluated their association with selected biochemical markers.

METHODS

Cross-sectional study within the UK biobank, including a total of 72,817 participants with 24-hour recall dietary data and 134 nuclear magnetic resonance metabolites. UPF and UNPF intakes were evaluated using the NOVA classification, and related metabolites were identified using elastic net penalized regression. A UPF metabolomic signature was computed as a weighted sum of UPF-related metabolites, using elastic net coefficients as weights. Associations between UPF and UNPF-related metabolites, and serum C-reactive protein (CRP), insulin-like growth factor-1(IGF-1), sex hormone-binding globulin (SHBG), and testosterone were examined using multiple quantile regression.

RESULTS

Elastic net model identified 17 and 15 metabolites uniquely related to UPF and UNPF intake, respectively. Acetoacetate, acetone, high-density lipoprotein (HDL) diameter, docosahexaenoic acid, linoleic acid, ω-3 fatty acids (FA), total lipids in large HDL cholesterol, and valine levels were decreased, but free cholesterol in extremely small very low-density lipoproteins (LDL), glutamine, glycine, glycoprotein acetyls, lactate, saturated FA, sphingomyelins, triglycerides in large LDL, and triglycerides in medium HDL levels were increased with high UPF intake. Opposite relationships were observed for UNPF intake. Heterogeneous associations were observed between UPF-related metabolites and CRP, IGF-1, SHBG, and testosterone levels. A UPF metabolomic signature was positively associated with CRP (regression coefficient per standard deviation, 1.45, 95% confidence interval, 1.385, 1.515) and negatively associated with IGF-1 (-3.16, -4.493, -1.827) and SHBG (-13.878, -15.291, -12.465).

CONCLUSION

A UPF metabolomic profile, including VLDL free cholesterol, saturated FA, triglycerides, glutamine, glycine, and glycoprotein acetyl was associated with inflammatory, insulin signalling, and reproductive biomarkers. This metabolomic profile should be explored as a potential mediators of UPF-disease associations, and as an objective marker of UPF intake.

Clinical and biochemical associations of urinary metabolites: quantitative epidemiological approach on renal-cardiometabolic biomarkers

BACKGROUND

Urinary metabolomics has demonstrated considerable potential to assess kidney function and its metabolic corollaries in health and disease. However, applications in epidemiology remain sparse due to technical challenges.

METHODS

We added 17 metabolites to an open-access urinary nuclear magnetic resonance metabolomics platform, extending the panel to 61 metabolites (n = 994). We also introduced automated quantification for 11 metabolites, extending the panel to 12 metabolites (+creatinine). Epidemiological associations between these 12 metabolites and 49 clinical measures were studied in three independent cohorts (up to 5989 participants). Detailed regression analyses with various confounding factors are presented for body mass index (BMI) and smoking.

RESULTS

Sex-specific population reference concentrations and distributions are provided for 61 urinary metabolites (419 men and 575 women), together with methodological intra-assay metabolite variations as well as the biological intra-individual and epidemiological population variations. For the 12 metabolites, 362 associations were found. These are mostly novel and reflect potential molecular proxies to estimate kidney function, as the associations cannot be simply explained by estimated glomerular filtration rate. Unspecific renal excretion results in leakage of amino acids (and glucose) to urine in all individuals. Seven urinary metabolites associated with smoking, providing questionnaire-independent proxy measures of smoking status in epidemiological studies. Common confounders did not affect metabolite associations with smoking, but insulin had a clear effect on most associations with BMI, including strong effects on 2-hydroxyisobutyrate, valine, alanine, trigonelline and hippurate.

CONCLUSIONS

Urinary metabolomics provides new insight on kidney function and related biomarkers on the renal-cardiometabolic system, supporting large-scale applications in epidemiology.

Small High-Density Lipoprotein and Omega-3 Fatty Acid Intake Differentiates Japanese and Japanese-Americans: The INTERLIPID Study

AIM

To identify the most differentiated serum lipids, especially concerning particle size and fractions, between Japanese living in Japan and Japanese-Americans in Hawaii, in the absence of possible genetic confounders, and cross-sectionally examine the associated modifiable lifestyle factors.

METHODS

Overall, 1,241 (aged 40-59 years) Japanese living in Japan and Japanese-Americans in Hawaii were included. We quantified 130 serum lipid profiles (VLDL 1-5, IDL, LDL 1-6, high-density lipoprotein [HDL] 1-4, and their subfractions) using Bruker's 1H-nuclear magnetic resonance spectrometer for the primary outcome. Modifiable lifestyle factors included body mass index (BMI), physical activity, alcohol and smoking habits, and 70 nutrient parameters. We evaluated the different lipids between the groups using partial least squares-discriminant analysis and association between extracted lipids and lifestyle factors using multivariable linear regression analysis.

RESULTS

Concentrations of HDL4, HDL with the smallest particle size, were lower in Japanese than in Japanese-Americans of both sexes. Higher fish-derived omega-3 fatty acid intake and lower alcohol intake were associated with lower HDL4 concentrations. A 1% higher kcal intake of total omega-3 fatty acids was associated with a 9.8-mg/dL lower HDL4. Fish-derived docosapentaenoic acid, eicosapentaenoic acid, and docosahexaenoic acid intake were inversely associated with HDL4 concentration. There was no relationship between country, sex, age, or BMI.

CONCLUSIONS

Japanese and Japanese-Americans can be differentiated based on HDL4 concentration. High fish intake among the Japanese may contribute to their lower HDL4 concentration. Thus, HDL particle size may be an important clinical marker for coronary artery diseases or a fish consumption biomarker.

Mediterranean diet related metabolite profiles and cognitive performance

BACKGROUND & AIMS

Evidence suggests that adherence to the Mediterranean diet (MedDiet) affects human metabolism and may contribute to better cognitive performance. However, the underlying mechanisms are not clear.

OBJECTIVE

We generated a metabolite profile for adherence to MedDiet and evaluated its cross-sectional association with aspects of cognitive performance.

METHODS

A total of 1250 healthy Greek middle-aged adults from the Epirus Health Study cohort were included in the analysis. Adherence to the MedDiet was assessed using the 14-point Mediterranean Diet Adherence Screener (MEDAS); cognition was measured using the Trail Making Test, the Verbal Fluency test and the Logical Memory test. A targeted metabolite profiling (n = 250 metabolites) approach was applied, using a high-throughput nuclear magnetic resonance platform. We used elastic net regularized regressions, with a 10-fold cross-validation procedure, to identify a metabolite profile for MEDAS. We evaluated the associations of the identified metabolite profile and MEDAS with cognitive tests, using multivariable linear regression models.

RESULTS

We identified a metabolite profile composed of 42 metabolites, mainly lipoprotein subclasses and fatty acids, significantly correlated with MedDiet adherence (Pearson r = 0.35, P-value = 5.5 × 10^-37). After adjusting for known risk factors and accounting for multiple testing, the metabolite profile and MEDAS were not associated with the cognitive tests.

CONCLUSIONS

A plasma metabolite profile related to better adherence to the MedDiet was not associated with the tested aspects of cognitive performance, in a middle-aged Mediterranean population.

Prevalence of Dementia and Main Subtypes in Mexico: The Study on Aging and Dementia in Mexico (SADEM)

BACKGROUND

Dementia is a priority public health issue due to its high prevalence worldwide and its economic, social, and health impact. However, there are few reports in Mexico based on formal tests and with a clinical approach based on the Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-5).

OBJECTIVE

This study estimates the prevalence of the main types of dementia among elderly people living in the community in Mexico City.

METHODS

A population-based, two-step study was conducted, including 6,204 elderly individuals aged 60 or above with in-home assessment. All participants were screened for cognitive impairment; those who presented some cognitive problem underwent a standardized neurological examination. Each diagnosis was based on the criteria for dementia in the DSM-5, and the final consensus diagnosis of dementia was determined by an expert panel.

RESULTS

The global estimated prevalence of dementia in the Mexican population was 7.8% met the criteria for Alzheimer's disease, 4.3% for vascular dementia, and 2.1% for mixed dementia. The prevalence of dementia was higher in women than in men (15.3% versus 12.5%, respectively).

CONCLUSION

These results provide evidence to propose strategies for Latin American countries where dementia represents a challenge due to the heterogeneity of the populations and socioeconomic disparities, requiring early diagnosis and at the first levels of care.

Dietary patterns and the risk of abnormal blood lipids among young adults: A prospective cohort study

BACKGROUND AND AIMS

The extent to which dietary patterns influence the risk of abnormal blood lipids throughout young adulthood remains unclear. The aim was to investigate whether early young adulthood dietary patterns predict the risk of abnormal blood lipids during later young adulthood.

METHODS AND RESULTS

We used data from a long running birth cohort study in Australia. Western dietary pattern rich in meats, processed foods and high-fat dairy products and prudent pattern rich in fruit, vegetables, fish, nuts, whole grains and low-fat dairy products were derived using principal component analysis at the 21-year follow-up from dietary data obtained using a food frequency questionnaire. After 9-years, fasting blood samples of all participants were collected and their total, low-density lipoprotein (LDL) and high-density lipoprotein (HDL) cholesterols and triglyceride (TG) levels were measured. Abnormal blood lipids were based on clinical cut-offs for total, LDL and HDL cholesterols, and TG and relative distributions for total:HDL and TG:HDL cholesterols ratios. Log-binomial models were used to estimate risk of each outcome in relation to dietary patterns. Greater adherence to the Western pattern predicted increased risks of high LDL (RR: 1.47; 95%CI: 1.06, 2.03) and TG (1.90; 1.25, 2.86), and high ratios of total:HDL (1.48; 1.00, 2.19) and TG:HDL (1.78; 1.18, 2.70) cholesterols in fully adjusted models. Conversely, a prudent pattern predicted reduced risks of low HDL (0.58; 0.42, 0.78) and high TG (0.66; 0.47, 0.92) and high total:HDL (0.71; 0.51, 0.98) and TG:HDL (0.61; 0.45, 0.84) cholesterols ratios.

CONCLUSION

This is the first prospective study to show greater adherence to unhealthy Western diet predicted increased risks of abnormal blood lipids, whereas healthy prudent diet predicted lower such risks in young adults. Addressing diets in early course may improve cardiovascular health of young adults.

Moderate alcohol consumption and lipoprotein subfractions: a systematic review of intervention and observational studies

CONTEXT

Moderate alcohol consumption is associated with decreased risk of cardiovascular disease (CVD) and improvement in cardiovascular risk markers, including lipoproteins and lipoprotein subfractions.

OBJECTIVE

To systematically review the relationship between moderate alcohol intake, lipoprotein subfractions, and related mechanisms.

DATA SOURCES

Following PRISMA, all human and ex vivo studies with an alcohol intake up to 60 g/d were included from 8 databases.

DATA EXTRACTION

A total of 17 478 studies were screened, and data were extracted from 37 intervention and 77 observational studies.

RESULTS

Alcohol intake was positively associated with all HDL subfractions. A few studies found lower levels of small LDLs, increased average LDL particle size, and nonlinear relationships to apolipoprotein B-containing lipoproteins. Cholesterol efflux capacity and paraoxonase activity were consistently increased. Several studies had unclear or high risk of bias, and heterogeneous laboratory methods restricted comparability between studies.

CONCLUSIONS

Up to 60 g/d alcohol can cause changes in lipoprotein subfractions and related mechanisms that could influence cardiovascular health.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. 98955.

Metabolomic profiles discriminating anxiety from depression

OBJECTIVE

Depression has been associated with metabolomic alterations. Depressive and anxiety disorders are often comorbid diagnoses and are suggested to share etiology. We investigated whether differential metabolomic alterations are present between anxiety and depressive disorders and which clinical characteristics of these disorders are related to metabolomic alterations.

METHODS

Data were from the Netherlands Study of Depression and Anxiety (NESDA), including individuals with current comorbid anxiety and depressive disorders (N = 531), only a current depression (N = 304), only a current anxiety disorder (N = 548), remitted depressive and/or anxiety disorders (N = 897), and healthy controls (N = 634). Forty metabolites from a proton nuclear magnetic resonance lipid-based metabolomics panel were analyzed. First, we examined differences in metabolites between disorder groups and healthy controls. Next, we assessed whether depression or anxiety clinical characteristics (severity and symptom duration) were associated with metabolites.

RESULTS

As compared to healthy controls, seven metabolomic alterations were found in the group with only depression, reflecting an inflammatory (glycoprotein acetyls; Cohen's d = 0.12, p = 0.002) and atherogenic-lipoprotein-related (e.g., apolipoprotein B: Cohen's d = 0.08, p = 0.03, and VLDL cholesterol: Cohen's d = 0.08, p = 0.04) profile. The comorbid group showed an attenuated but similar pattern of deviations. No metabolomic alterations were found in the group with only anxiety disorders. The majority of metabolites associated with depression diagnosis were also associated with depression severity; no associations were found with anxiety severity or disease duration.

CONCLUSION

While substantial clinical overlap exists between depressive and anxiety disorders, this study suggests that altered inflammatory and atherogenic-lipoprotein-related metabolomic profiles are uniquely associated with depression rather than anxiety disorders.

Metabolic profiles of socio-economic position: a multi-cohort analysis

Background

Low socio-economic position (SEP) is a risk factor for multiple health outcomes, but its molecular imprints in the body remain unclear.

Methods

We examined SEP as a determinant of serum nuclear magnetic resonance metabolic profiles in ∼30 000 adults and 4000 children across 10 UK and Finnish cohort studies.

Results

In risk-factor-adjusted analysis of 233 metabolic measures, low educational attainment was associated with 37 measures including higher levels of triglycerides in small high-density lipoproteins (HDL) and lower levels of docosahexaenoic acid (DHA), omega-3 fatty acids, apolipoprotein A1, large and very large HDL particles (including levels of their respective lipid constituents) and cholesterol measures across different density lipoproteins. Among adults whose father worked in manual occupations, associations with apolipoprotein A1, large and very large HDL particles and HDL-2 cholesterol remained after adjustment for SEP in later life. Among manual workers, levels of glutamine were higher compared with non-manual workers. All three indicators of low SEP were associated with lower DHA, omega-3 fatty acids and HDL diameter. At all ages, children of manual workers had lower levels of DHA as a proportion of total fatty acids.

Conclusions

Our work indicates that social and economic factors have a measurable impact on human physiology. Lower SEP was independently associated with a generally unfavourable metabolic profile, consistent across ages and cohorts. The metabolites we found to be associated with SEP, including DHA, are known to predict cardiovascular disease and cognitive decline in later life and may contribute to health inequalities.

Comprehensive lipid and metabolite profiling in healthy adults with low and high consumption of fatty fish: a cross-sectional study

Fish consumption is associated with reduced risk of CVD, which may be partly mediated by alterations in plasma lipids, such as HDL-cholesterol. However, comprehensive analyses of associations between fatty fish consumption and lipoprotein subclass profile are limited and show inconsistent results. Therefore, the aim of the present exploratory study was to investigate the association between fatty fish consumption and lipoprotein subclass particle concentrations and composition, with an emphasis on HDL. We performed a comprehensive plasma metabolite profiling in 517 healthy adults, using a targeted high-throughput NMR spectroscopy platform. The participants were divided into tertiles based on consumption of fatty fish, reported through a validated FFQ. We compared the concentration of metabolites between the participants in the lowest and highest tertiles of fatty fish consumption. We show that high consumers of fatty fish (>223 g/week, median intake 294 g/week) had higher particle concentrations and content of total lipids, free cholesterol and phospholipids in large and extra-large HDL particles and higher content of total cholesterol, cholesteryl esters and TAG in large HDL particles than low consumers (<107 g/week, median intake 58 g/week). Using fatty fish consumption as a continuous variable, we found that fatty fish consumption was associated with lower levels of the inflammation marker glycoprotein acetyls. In conclusion, high consumers of fatty fish seem to have a more favourable HDL-cholesterol-related lipoprotein profile and anti-inflammatory phenotype than low consumers of fatty fish. Thus, these data support the current Norwegian dietary recommendations for fish consumption regarding CVD risk.

Serum Metabolomic Signatures Can Predict Subclinical Atherosclerosis in Patients With Systemic Lupus Erythematosus

[Figure: see text].

Increased apolipoprotein-B:A1 ratio predicts cardiometabolic risk in patients with juvenile onset SLE

BACKGROUND

Cardiovascular disease is a leading cause of mortality in patients with juvenile-onset systemic lupus erythematosus (JSLE). Traditional factors for cardiovascular risk (CVR) prediction are less robust in younger patients. More reliable CVR biomarkers are needed for JSLE patient stratification and to identify therapeutic approaches to reduce cardiovascular morbidity and mortality in JSLE.

METHODS

Serum metabolomic analysis (including >200 lipoprotein measures) was performed on a discovery (n=31, median age 19) and validation (n=31, median age 19) cohort of JSLE patients. Data was analysed using cluster, receiver operating characteristic analysis and logistic regression. RNA-sequencing assessed gene expression in matched patient samples.

FINDINGS

Hierarchical clustering of lipoprotein measures identified and validated two unique JSLE groups. Group-1 had an atherogenic and Group-2 had an atheroprotective lipoprotien profile. Apolipoprotein(Apo)B:ApoA1 distinguished the two groups with high specificity (96.2%) and sensitivity (96.7%). JSLE patients with high ApoB:ApoA1 ratio had increased CD8+ T-cell frequencies and a CD8+ T-cell transcriptomic profile enriched in genes associated with atherogenic processes including interferon signaling. These metabolic and immune signatures overlapped statistically significantly with lipid biomarkers associated with sub-clinical atherosclerosis in adult SLE patients and with genes overexpressed in T-cells from human atherosclerotic plaque respectively. Finally, baseline ApoB:ApoA1 ratio correlated positively with SLE disease activity index (r=0.43, p=0.0009) and negatively with Lupus Low Disease Activity State (r=-0.43, p=0.0009) over 5-year follow-up.

INTERPRETATION

Multi-omic analysis identified high ApoB:ApoA1 as a potential biomarker of increased cardiometabolic risk and worse clinical outcomes in JSLE. ApoB:ApoA1 could help identify patients that require increased disease monitoring, lipid modification or lifestyle changes.

FUNDING

Lupus UK, The Rosetrees Trust, British Heart Foundation, UCL & Birkbeck MRC Doctoral Training Programme and Versus Arthritis.

Achievement of the Targets of the 20-Year Infancy-Onset Dietary Intervention-Association with Metabolic Profile from Childhood to Adulthood

The Special Turku Coronary Risk Factor Intervention Project (STRIP) is a prospective infancy-onset randomized dietary intervention trial targeting dietary fat quality and cholesterol intake, and favoring consumption of vegetables, fruit, and whole-grains. Diet (food records) and circulating metabolites were studied at six time points between the ages of 9-19 years (n = 549-338). Dietary targets for this study were defined as (1) the ratio of saturated fat (SAFA) to monounsaturated and polyunsaturated fatty acids (MUFA + PUFA) < 1:2, (2) intake of SAFA < 10% of total energy intake, (3) fiber intake ≥ 80th age-specific percentile, and (4) sucrose intake ≤ 20th age-specific percentile. Metabolic biomarkers were quantified by high-throughput nuclear magnetic resonance metabolomics. Better adherence to the dietary targets, regardless of study group allocation, was assoiated with higher serum proportion of PUFAs, lower serum proportion of SAFAs, and a higher degree of unsaturation of fatty acids. Achieving ≥ 1 dietary target resulted in higher low-density lipoprotein (LDL) particle size, lower circulating LDL subclass lipid concentrations, and lower circulating lipid concentrations in medium and small high-density lipoprotein subclasses compared to meeting 0 targets. Attaining more dietary targets (≥2) was associated with a tendency to lower lipid concentrations of intermediate-density lipoprotein and very low-density lipoprotein subclasses. Thus, adherence to dietary targets is favorably associated with multiple circulating fatty acids and lipoprotein subclass lipid concentrations, indicative of better cardio-metabolic health.

An integrative machine learning approach to discovering multi-level molecular mechanisms of obesity using data from monozygotic twin pairs

We combined clinical, cytokine, genomic, methylation and dietary data from 43 young adult monozygotic twin pairs (aged 22-36 years, 53% female), where 25 of the twin pairs were substantially weight discordant (delta body mass index > 3 kg m^-2). These measurements were originally taken as part of the TwinFat study, a substudy of The Finnish Twin Cohort study. These five large multivariate datasets (comprising 42, 71, 1587, 1605 and 63 variables, respectively) were jointly analysed using an integrative machine learning method called group factor analysis (GFA) to offer new hypotheses into the multi-molecular-level interactions associated with the development of obesity. New potential links between cytokines and weight gain are identified, as well as associations between dietary, inflammatory and epigenetic factors. This encouraging case study aims to enthuse the research community to boldly attempt new machine learning approaches which have the potential to yield novel and unintuitive hypotheses. The source code of the GFA method is publically available as the R package GFA.

Plasma metabolomic profiles associated with infant food allergy with further consideration of other early life factors

BACKGROUND

Fatty acids have been implicated in early life immune development. Food allergy provides a clear phenotype of early allergic disease. Fish oil and vitamin D have immune-modulating properties. We aimed to identify the metabolomic profile of (i) infant food allergy and (ii) factors linked to food allergy in past studies such as fish oil supplementation and serum 25OHD3 levels in early life.

METHODS

NMR was used to quantify 73 metabolites in plasma of 1 year old infants from the Barwon Infant Study (n=485). Logistic regression models were used to examine associations between infant metabolome and food allergy in infants. Linear regression models were used to describe associations between maternal fish oil supplementation and 25OHD3 levels with infant metabolites.

RESULTS

A higher linoleic acid: total fatty acid (FA) ratio and phenylalanine level were associated with higher odds of food allergy. Antenatal fish oil supplementation was positively associated with docosahexaenoic acid (DHA) and omega-3 related metabolite levels. Postnatal 25OHD3 levels at 1 year of age were positively associated with several FA measures and creatinine and inversely with the saturated FA: total FA ratio. Only the postnatal 25OHD3 patterns persisted after adjustment for multiple comparisons.

CONCLUSIONS

Infants with food allergy had altered fatty acid profiles at one year. Fish oil supplementation in pregnancy was associated with higher DHA and omega-3 related metabolites at 1 year of age. Associations were modest and the most robustly altered metabolomic profiles were with postnatal 25OHD3 levels.

Habitual Fish Consumption, n-3 Fatty Acids, and Nuclear Magnetic Resonance Lipoprotein Subfractions in Women

Background

Supplementation with omega‐3 (n‐3) fatty acid or dietary fish may protect against atherosclerosis, but the potential mechanisms are unclear. Prior studies found modest triglyceride‐lowering effects and slight increases in LDL (low‐density lipoprotein) cholesterol. Limited evidence has examined n‐3 effects on more detailed lipoprotein biomarkers.

Methods and Results

We conducted a study of 26 034 healthy women who reported information on fish and n‐3 intake from a 131‐item food‐frequency questionnaire. We measured plasma lipids, apolipoproteins, and nuclear magnetic resonance spectroscopy lipoproteins and examined their associations with dietary intake of fish, total n‐3, and the n‐3 subtypes (eicosapentaenoic, docosahexaenoic, and α‐linolenic acids). Top‐ versus bottom‐quintile intake of fish and n‐3 were significantly associated with lower triglyceride and large VLDL (very‐low‐density lipoprotein) particles. Fish intake, but not total n‐3, was positively associated with total cholesterol, LDL cholesterol, apolipoprotein B, and larger LDL size, but only α‐linolenic acid was associated with lower LDL cholesterol. Total n‐3, docosahexaenoic acid, and α‐linolenic acid intake were also positively associated with larger HDL (high‐density lipoprotein) size and large HDL particles. High eicosapentaenoic acid intake was significantly associated with only a decreased level of VLDL particle concentration and VLDL triglyceride content. The n‐3 fatty acids had some similarities but also differed in their associations with prospective cardiovascular disease risk patterns.

Conclusions

Higher consumption of fish and n‐3 fatty acids were associated with multiple measures of lipoproteins that were mostly consistent with cardiovascular prevention, with differences noted for high intake of eicosapentaenoic acid versus docosahexaenoic acid and α‐linolenic acid that were apparent with more detailed lipoprotein phenotyping. These hypothesis‐generating findings warrant further study in clinical trials.

Clinical Trial Registration

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00000479.

FinnTwin12 Cohort: An Updated Review

This review offers an update on research conducted with FinnTwin12 (FT12), the youngest of the three Finnish Twin Cohorts. FT12 was designed as a two-stage study. In the first stage, we conducted multiwave questionnaire research enrolling all eligible twins born in Finland during 1983-1987 along with their biological parents. In stage 2, we intensively studied a subset of these twins with in-school assessments at age 12 and semistructured poly-diagnostic interviews at age 14. At baseline, parents of intensively studied twins were administered the adult version of the interview. Laboratory studies with repeat interviews, neuropsychological tests, and collection of DNA were made of intensively studied twins during follow-up in early adulthood. The basic aim of the FT12 study design was to obtain information on individual, familial and school/neighborhood risks for substance use/abuse prior to the onset of regular tobacco and alcohol use and then track trajectories of use and abuse and their consequences into adulthood. But the longitudinal assessments were not narrowly limited to this basic aim, and with multiwave, multirater assessments from ages 11 to 12, the study has created a richly informative data set for analyses of gene-environment interactions of both candidate genes and genomewide measures with measured risk-relevant environments. Because 25 years have elapsed since the start of the study, we are planning a fifth-wave follow-up assessment.

Disentangling the Effects of Monounsaturated Fatty Acids from Other Components of a Mediterranean Diet on Serum Metabolite Profiles: A Randomized Fully Controlled Dietary Intervention in Healthy Subjects at Risk of the Metabolic Syndrome

SCOPE

The Mediterranean (MED) diet has been associated with a decreased risk of cardiovascular diseases. It is unclear whether this health effect can be mainly contributed to high intakes of monounsaturated fatty acids (MUFA), characteristic for the MED diet, or whether other components of a MED diet also play an important role.

METHODS AND RESULTS

A randomized fully controlled parallel trial is performed to examine the effects of the consumption of a saturated fatty acid rich diet, a MUFA-rich diet, or a MED diet for 8 weeks on metabolite profiles, in 47 subjects at risk of the metabolic syndrome. A total of 162 serum metabolites are assessed before and after the intervention by using a targeted NMR platform. Fifty-two metabolites are changed during the intervention (false discovery rate [FDR] p < 0.05). Both the MUFA and MED diet decrease exactly the same fractions of LDL, including particle number, lipid, phospholipid, and free cholesterol fraction (FDR p < 0.05). The MED diet additionally decreases the larger subclasses of very-low-density lipoprotein (VLDL), related VLDL fractions, VLDL-triglycerides, and serum-triglycerides (FDR p < 0.05).

CONCLUSION

The findings clearly demonstrate that the MUFA component is responsible for reducing LDL subclasses and fractions, and therefore causes an antiatherogenic lipid profile. Interestingly, consumption of the other components in the MED diet show additional health effects.

Intake of Fatty Fish Alters the Size and the Concentration of Lipid Components of HDL Particles and Camelina Sativa Oil Decreases IDL Particle Concentration in Subjects with Impaired Glucose Metabolism

SCOPE

Intake of long-chain n-3 PUFAs affects the lipoprotein subclass profile, whereas the effect of shorter chain n-3 PUFAs remains unclear. We investigated the effect of fish and camelina sativa oil (CSO) intakes on lipoprotein subclasses.

METHODS AND RESULTS

Altogether, 79 volunteers with impaired glucose metabolism were randomly assigned to CSO, fatty fish (FF), lean fish (LF), or control group for 12 weeks. Nuclear magnetic resonance spectroscopy was used to determine lipoprotein subclasses and their lipid components. The average HDL particle size increased in the FF group (overall p = 0.032) as compared with the control group. Serum concentrations of cholesterol in HDL and HDL₂ (overall p = 0.024 and p = 0.021, respectively) and total lipids and phospholipids in large HDL particles (overall p = 0.012 and p = 0.019, respectively) increased in the FF group, differing significantly from the LF group. The concentration of intermediate-density lipoprotein (IDL) particles decreased in the CSO group (overall p = 0.033) as compared with the LF group.

CONCLUSION

Our study suggests that FF intake causes a shift toward larger HDL particles and increases the concentration of lipid components in HDL, which may be associated with the antiatherogenic properties of HDL. Furthermore, CSO intake decreases IDL particle concentration. These changes may favorably affect cardiovascular risk.

Diet quality as assessed by the Healthy Food Intake Index and relationship with serum lipoprotein particles and serum fatty acids in pregnant women at increased risk for gestational diabetes

The importance of overall diet in modifying circulating lipoprotein particles and fatty acids during pregnancy is unclear. We examined the relationships of diet quality as assessed by the validated Healthy Food Intake Index (HFII) with serum HDL, LDL and VLDL particle concentrations and sizes and proportions of serum fatty acids in pregnant women at high risk for gestational diabetes mellitus (GDM). Overall, 161 women with a BMI of ≥30 kg/m2 and/or a history of GDM were drawn from the Finnish Gestational Diabetes Prevention Study, which is a dietary and exercise intervention trial to prevent GDM. At baseline, the HFII score was inversely related to concentrations of HDL particles (P=0·010) and MUFA (P=0·010) and positively related to concentrations of n-3 (P<0·001) and n-6 (P=0·003) PUFA. The significance for MUFA disappeared after adjustments. An increase in the HFII score from the first to second trimester of pregnancy correlated with reduced VLDL particle size (r −0·16, 95 % CI −0·31, −0·01), decreased MUFA concentrations (r −0·17, 95 % CI −0·31, −0·01) and elevated n-6 PUFA concentrations (r 0·16, 95 % CI 0·01, 0·31). In the maximum-adjusted model, the results remained significant except for VLDL particle size. These findings suggest that higher diet quality as defined by the HFII is related to a more favourable serum fatty acid profile, whereas the relationship with serum lipoprotein profile is limited in pregnant women at increased GDM risk.

Associations of Anthropometric Characteristics, Dietary Habits, and Aerobic Capacity With Cardiovascular Risk Factors of Health-Science Students

The aim of this cross-sectional study was to study the relative importance of dietary habits and aerobic capacity in parameters related to cardiovascular risk in 271 female and 95 male health-science students (mean age = 19.1 ± 1.4 years). In females, fatty-meat consumption predicted triglycerides (β = .649, p < .001) and high-density lipoprotein (HDL; β = -.242, p = .001) and low-density lipoprotein (LDL; β = .373, p < .001) cholesterol levels. Consumption of nuts, legumes, and complex carbohydrates predicted triglyceride (β = -.099, p = .074), HDL (β = .231, p = .001), and LDL (β = -.155, p = .025) levels, respectively. Aerobic capacity (β = -.245, p < .001) and fatty-meat intake (β = .230, p < .001) predicted diastolic blood pressure (BP); body mass index (BMI) predicted systolic BP (β = .340, p < .001). In males, body fat percentage was the strongest predictor of triglycerides (β = .348, p = .004), cholesterol (β = .366, p = .006), HDL (β = -.378, p = .004), and LDL (β = .271, p = .043) levels. Aerobic capacity (β = -.263, p = .013) and fatty-meat consumption (β = .334, p = .005) independently predicted triglyceride levels. Nut (β = -.286, p = .013) and fatty-meat intake (β = .361, p = .002) predicted systolic BP, while BMI predicted diastolic BP (β = .209, p = .045). As health sciences students, these participants are future health professionals; targeting such populations is important for chronic disease prevention.

Association of circulating metabolites with healthy diet and risk of cardiovascular disease: analysis of two cohort studies

Diet may modify metabolomic profiles towards higher or lower cardiovascular disease (CVD) risk. We aimed to identify metabolite profiles associated with high adherence to dietary recommendations - the Alternative Healthy Eating Index (AHEI) - and the extent to which metabolites associated with AHEI also predict incident CVD. Relations between AHEI score and 80 circulating lipids and metabolites, quantified by nuclear magnetic resonance metabolomics, were examined using linear regression models in the Whitehall II study (n = 4824, 55.9 ± 6.1 years, 28.0% women) and were replicated in the Cardiovascular Risk in Young Finns Study (n = 1716, 37.7 ± 5.0 years, 56.3% women). We used Cox models to study associations between metabolites and incident CVD over the 15.8-year follow-up in the Whitehall II study. After adjustment for confounders, higher AHEI score (indicating healthier diet) was associated with higher degree of unsaturation of fatty acids (FA) and higher ratios of polyunsaturated FA, omega-3 and docosahexaenoic acid relative to total FA in both Whitehall II and Young Finns studies. A concordance of associations of metabolites with higher AHEI score and lower CVD risk was observed in Whitehall II. Adherence to healthy diet seems to be associated with specific FA that reduce risk of CVD.

Is single-child family associated with cardio-metabolic risk factors: the CASPIAN-V study

BACKGROUND

In the present study, the association of the cardio-metabolic risk factors and the status of single-child family were studied in a national representative sample of Iranian children and adolescents.

METHODS

This cross sectional study was conducted as the fifth round of "Childhood and Adolescence Surveillance and PreventIon of Adult Non- communicable disease" surveys. The students' questionnaire was derived from the World Health Organization-Global School Student Health Survey. Using survey data analysis methods, data from questionnaires'; anthropometric measures and biochemical information analyzed by logistic regression analysis.

RESULTS

Overall, 14,274 students completed the survey (participation rate: 99%); the participation rate for blood sampling from students was 91.5%. Although in univariate logistic regression model, single child students had an increased risk of abdominal obesity [OR: 1.37; 95% CI: 1.19-1.58)], high SBP [OR: 1.58; 95% CI:1.17-2.14)], high BP [OR: 1.21; 95% CI:1.01-1.45)] and generalized obesity [OR: 1.27; 95% CI:1.06-1.52)], in multiple logistic regression model, only association of single child family with abdominal obesity remained statistically significant [OR: 1.28; 95% CI:1.1-1.50)]. Also in multivariate logistic regression model, for each increase of a child in the family the risk of abdominal obesity [OR: 0.95; 95% CI: 0.91-0.97), high SBP [OR: 0.88; 95% CI: 0.81-0.95)] and generalized obesity [OR: 0.95; 95% CI: 0.91-0.99)] decreased significantly.

CONCLUSION

The findings of this study serve as confirmatory evidence on the association of cardio-metabolic risk factors with single-child family in children and adolescents. The findings of study could be used for better health planning and more complementary research.

Effect of a high-fat diet and alcohol on cutaneous repair: A systematic review of murine experimental models

BACKGROUND AND PURPOSE

Chronic alcohol intake associated with an inappropriate diet can cause lesions in multiple organs and tissues and complicate the tissue repair process. In a systematic review, we analyzed the relevance of alcohol and high fat consumption to cutaneous and repair, compared the main methodologies used and the most important parameters tested. Preclinical investigations with murine models were assessed to analyze whether the current evidence support clinical trials.

METHODS

The studies were selected from MEDLINE/PubMed and Scopus databases, according to Fig 1. All 15 identified articles had their data extracted. The reporting bias was investigated according to the ARRIVE (Animal Research: Reporting of in Vivo Experiments) strategy.

RESULTS

In general, animals offered a high-fat diet and alcohol showed decreased cutaneous wound closure, delayed skin contraction, chronic inflammation and incomplete re-epithelialization.

CONCLUSION

In further studies, standardized experimental design is needed to establish comparable study groups and advance the overall knowledge background, facilitating data translatability from animal models to human clinical conditions.

Effect of diets rich in either saturated fat or n-6 polyunsaturated fatty acids and supplemented with long-chain n-3 polyunsaturated fatty acids on plasma lipoprotein profiles

BACKGROUND/OBJECTIVES

Abnormalities in lipoprotein profiles (size, distribution and concentration) play an important role in the pathobiology of atherosclerosis and coronary artery disease. Dietary fat, among other factors, has been demonstrated to modulate lipoprotein profiles. We aimed to investigate if background dietary fat (saturated, SFA versus omega-6 polyunsaturated fatty acids, n-6PUFA) was a determinant of the effects of LCn-3PUFA supplementation on lipoprotein profiles.

SUBJECTS/METHODS

A randomized controlled clinical intervention trial in a parallel design was conducted. Healthy subjects (n=26) were supplemented with 400 mg eicosapentaenoic acid plus 2000 mg docosahexaenoic acid daily and randomized to consume diets rich in either SFA or n-6PUFA for a period of 6 weeks. Blood samples, collected at baseline and after 6 weeks of intervention, were assessed for plasma lipoprotein profiles (lipoprotein size, concentration and distribution in subclasses) determined using nuclear magnetic resonance spectroscopy.

RESULTS

Study participants receiving the SFA or the n-6PUFA enriched diets consumed similar percentage energy from fat (41 and 42% respectively, P=0.681). However, subjects on the SFA diet consumed 50% more energy as saturated fat and 77% less as linoleic acid than those consuming the n-6PUFA diet (P<0.001). The diets rich in SFA and n-6PUFA reduced the concentration of total very-low-density lipoprotein (VLDL) particles (P<0.001, both), and their subclasses and increased VLDL (P=0.042 and P=0.007, respectively) and LDL (P=0.030 and 0.027, respectively) particle size. In addition, plasma triglyceride concentration was significantly reduced by LCn-3PUFA supplementation irrespective of the dietary fat.

CONCLUSIONS

LCn-3PUFA modulated lipoprotein profiles in a similar fashion when supplemented in diets rich in either SFA or n-6PUFA.

The amelioration of plasma lipids by Korean traditional confectionery in middle-aged women: A cross-over study with western cookie

BACKGROUND/OBJECTIVES

The purpose of this study was to examine whether plasma lipid profiles are affected differently by snack kinds with equal calorific values.

SUBJECTS/METHODS

We compared a Korean traditional confectionery (dasik) with Western confectionery (cookie) in this regard. Controlled cross-over study consisted of two 3-week snack intake phases and for separating, a 2-week washout period (3–2–3) was carried out with 30 healthy women aged between 40-59 years old. Brown rice based Korean traditional confectionery and wheat flour based Western confectionery were used. The participants consumed either dasik or cookie every day for 3 weeks, providing 93 kcal a day.

RESULTS

The total cholesterol (TC) in the dasik group had decreased significantly after 3 weeks (P < 0.05). Furthermore, in the dasik group, reduction in TC and low-density lipoprotein-cholesterol were greater than those in the cookie group (P < 0.05).

CONCLUSIONS

Prioritizing functional snacks like dasik improves plasma lipid profiles; this may be useful information for individuals who cannot refrain from snacking.

Dietary patterns and changes in cardiovascular risk factors in apparently healthy Chinese women: a longitudinal study

Little is known of the relationships between dietary patterns and cardiovascular risk factors in China. We therefore designed a 3-year longitudinal study to evaluate the impacts of dietary patterns on changes in these factors among Chinese women. A total of 1,028 subjects who received health examination in 2011 and 2014 were recruited. Three major dietary patterns (“vegetable pattern”, “meat pattern”, and “animal offal-dessert-and-alcohol pattern”) were derived by principal component analysis based on validated food frequency questionnaires. Cardiovascular risk factors were standardized to create within-cohort z-scores and the changes in them were calculated as the differences between 2011 and 2014. Relationships between dietary patterns and changes in cardiovascular risk factors were assessed using general linear model. After adjustment for potential confounders, changes in total cholesterol and fasting blood glucose decreased across the tertiles of vegetable pattern (p for trend = 0.01 and 0.04, respectively). While, changes in diastolic blood pressure, total cholesterol and low density lipoprotein cholesterol increased across the tertiles of animal offal-dessert-and-alcohol pattern (p for trend = 0.02, 0.01, and 0.02, respectively). The findings suggest that vegetable pattern was beneficially related to cardiovascular risk factors, whereas animal offal-dessert-and-alcohol pattern was detrimental related to these factors among apparently healthy Chinese women.

Evaluation of dietary patterns among Norwegian postmenopausal women using plasma carotenoids as biomarkers

A number of studies have examined dietary patterns in various populations. However, to study to what extent such patterns capture meaningful differences in consumption of foods is of interest. In the present study, we identified important dietary patterns in Norwegian postmenopausal women (age 50-69 years, n 361), and evaluated these patterns by examining their associations with plasma carotenoids. Diet was assessed by a 253-item FFQ. These 253 food items were categorised into forty-six food groups, and dietary patterns were identified using principal component analysis. We used the partial correlation coefficient (r(adj)) and multiple linear regression analysis to examine the associations between the dietary patterns and the plasma carotenoids α-carotene, β-carotene, β-cryptoxanthin, lutein, lycopene and zeaxanthin. Overall, four dietary patterns were identified: the 'Western'; 'Vegetarian'; 'Continental'; 'High-protein'. The 'Western' dietary pattern scores were significantly inversely correlated with plasma lutein, zeaxanthin, lycopene and total carotenoids (-0·25 ≤ r(adj) ≤ -0·13). The 'Vegetarian' dietary pattern scores were significantly positively correlated with all the plasma carotenoids (0·15 ≤ r(adj) ≤ 0·24). The 'Continental' dietary pattern scores were significantly inversely correlated with plasma lutein and α-carotene (r(adj) = -0·13). No significant association between the 'High-protein' dietary pattern scores and the plasma carotenoids was found. In conclusion, the healthy dietary pattern, the 'Vegetarian' pattern, is associated with a more favourable profile of the plasma carotenoids than our unhealthy dietary patterns, the 'Western' and 'Continental' patterns.

Epidemiology: disease associations and modulators of HDL-related biomarkers

Epidemiological studies have shown an inverse association between high-density lipoprotein cholesterol (HDL-C) levels and risk of ischemic heart disease. In addition, a low level of HDL-C has been shown to be a risk factor for other diseases not related to atherosclerosis. However, recent studies have not supported a causal effect of HDL-C in the development of atherosclerosis. Furthermore, new drugs markedly elevating HDL-C levels have been disappointing with respect to clinical endpoints. Earlier, most studies have focused almost exclusively on the total HDL-C without regard to the chemical composition or multiple subclasses of HDL particles. Recently, there have been efforts to dissect the HDL fraction into as many well-defined subfractions and individual molecules of HDL particles as possible. On the other hand, the focus is shifting from the structure and composition to the function of HDL particles. Biomarkers and mechanisms that could potentially explain the beneficial characteristics of HDL particles unrelated to their cholesterol content have been sought with sophisticated methods such as proteomics, lipidomics, metabonomics, and function studies including efflux capacity. These new approaches have been used in order to resolve the complex effects of diseases, conditions, environmental factors, and genes in relation to the protective role of HDL but high-throughput methods are still needed for large-scale epidemiological studies.

Effects of whole grain, fish and bilberries on serum metabolic profile and lipid transfer protein activities: a randomized trial (Sysdimet)

OBJECTIVE

We studied the combined effects of wholegrain, fish and bilberries on serum metabolic profile and lipid transfer protein activities in subjects with the metabolic syndrome.

METHODS

Altogether 131 subjects (40-70 y, BMI 26-39 kg/m(2)) with impaired glucose metabolism and features of the metabolic syndrome were randomized into three groups with 12-week periods according to a parallel study design. They consumed either: a) wholegrain and low postprandial insulin response grain products, fatty fish 3 times a week, and bilberries 3 portions per day (HealthyDiet), b) wholegrain and low postprandial insulin response grain products (WGED), or c) refined wheat breads as cereal products (Control). Altogether 106 subjects completed the study. Serum metabolic profile was studied using an NMR-based platform providing information on lipoprotein subclasses and lipids as well as low-molecular-weight metabolites.

RESULTS

There were no significant differences in clinical characteristics between the groups at baseline or at the end of the intervention. Mixed model analyses revealed significant changes in lipid metabolites in the HealthyDiet group during the intervention compared to the Control group. All changes reflected increased polyunsaturation in plasma fatty acids, especially in n-3 PUFAs, while n-6 and n-7 fatty acids decreased. According to tertiles of changes in fish intake, a greater increase of fish intake was associated with increased concentration of large HDL particles, larger average diameter of HDL particles, and increased concentrations of large HDL lipid components, even though total levels of HDL cholesterol remained stable.

CONCLUSIONS

The results suggest that consumption of diet rich in whole grain, bilberries and especially fatty fish causes changes in HDL particles shifting their subclass distribution toward larger particles. These changes may be related to known protective functions of HDL such as reverse cholesterol transport and could partly explain the known protective effects of fish consumption against atherosclerosis.

TRIAL REGISTRATION

The study was registered at ClinicalTrials.gov NCT00573781.

Cross-sectional and longitudinal associations of circulating omega-3 and omega-6 fatty acids with lipoprotein particle concentrations and sizes: population-based cohort study with 6-year follow-up

BACKGROUND

Cross-sectional studies have suggested that serum omega-3 (n-3) and omega-6 (n-6) polyunsaturated fatty acids (PUFAs) are related to favorable lipoprotein particle concentrations. We explored the associations of serum n-3 and n-6 PUFAs with lipoprotein particle concentrations and sizes in a general population cohort at baseline and after 6 years.

FINDINGS

The cohort included 665 adults (274 men) with a 6-year follow-up. Nutritional counseling was given at baseline. Serum n-3 and n-6 PUFAs and lipoprotein particle concentrations and the mean particle sizes of VLDL, LDL, and HDL were quantified by nuclear magnetic resonance (NMR) spectroscopy for all baseline and follow-up samples at the same time. Concentrations of n-3 and n-6 PUFAs were expressed relative to total fatty acids. At baseline, n-3 PUFAs were not associated with lipoprotein particle concentrations. A weak negative association was observed for VLDL (P = 0.021) and positive for HDL (P = 0.011) particle size. n-6 PUFA was negatively associated with VLDL particle concentration and positively with LDL (P < 0.001) and HDL particle size (P < 0.001). The 6-year change in n-3 PUFA correlated positively with the change in particle size for HDL and LDL lipoproteins but negatively with VLDL particle size. An increase in 6-year levels of n-6 PUFAs was negatively correlated with the change in VLDL particle concentration and size, and positively with LDL particle size.

CONCLUSION

Change in circulating levels of both n-3 and n-6 PUFAs, relative to total fatty acids, during 6 years of follow-up are associated with changes in lipoprotein particle size and concentrations at the population level.

Association between serum fatty acids and lipoprotein subclass profile in healthy young adults: exploring common genetic and environmental factors

OBJECTIVE

Little is known about the associations of serum fatty acids with lipoprotein profile and the underlying genetic and environmental etiology of these relationships. We aimed to analyze the phenotypic association of serum n-6 and n-3 polyunsaturated (PUFAs), monounsaturated (MUFAs) and saturated (SFAs) fatty acids (relative proportion to total fatty acids) with lipids and lipoproteins, and to quantify common genetic and environmental factors determining their covariation.

METHODS

Two cohorts of healthy Finnish twins were assessed in young adulthood. Data were available for 1269 individual twins including 561 complete pairs. Serum metabolites were measured by nuclear magnetic resonance spectroscopy. Bivariate quantitative genetic models were used to decompose the phenotypic covariance between the pairs of traits into genetic and environmental components.

RESULTS

Among the strongest correlations observed, serum total n-6 PUFAs and linoleic acid were inversely (max. r=-0.65) and MUFAs positively (max. r=0.63) correlated with triglycerides and very low-density lipoprotein (VLDL) particle concentration, particularly with large VLDL (for n-6 PUFAs) and medium VLDL (for MUFAs). Genetic factors significantly contributed to their covariance with bivariate heritability estimates ranging from 44% to 56% for n-6 PUFAs and 58% to 66% for MUFAs. Genetic correlations with lipid traits were moderate to high (max. rA=-0.59 and 0.70 for n-6 PUFAs and MUFAs, respectively). Statistically significant, but substantially weaker phenotypic correlations of total n-3 PUFAs, docosahexaenoic acid (DHA) and SFAs with lipoprotein profile were not decomposed into their genetic and environmental components.

CONCLUSION

Shared genetic factors are important in explaining why higher concentrations of serum n-6 PUFAs and lower concentrations of serum MUFAs strongly associate with lower triglyceride and VLDL particle concentrations.