Associations of Serum Fatty Acid Proportions with Obesity, Insulin Resistance, Blood Pressure, and Fatty Liver: The Cardiovascular Risk in Young Finns Study

Association Between Circulating Fatty Acids and Blood Pressure: A Review

PURPOSE OF REVIEW

High blood pressure (BP) or hypertension (HTN) remains key risk factors for cardiovascular disease (CVD). Circulating fatty acids (FAs) in the blood can affect directly cardiovascular hemodynamics and serves as building blocks for endocrine mediators modifying inflammatory processes and vascular function. This review aims to describe optimal circulating FA profiles for BP to adjust dietary recommendations for HTN prevention.

RECENT FINDINGS

Recent research highlights the critical role of FAs in regulating inflammation and vascular function. Different FAs have varying effects on oxidative stress, insulin resistance, inflammation, and vascular dysfunction, all contributing to HTN. These findings emphasize the importance of FAs in managing BP and preventing CVD. Up-to-now, findings suggest that eicosapentaenoic acid (20:5n3), docosahexaenoic acid (22:6n3), arachidic acid (20:0), behenic acid (22:0) and lignoceric acid (24:0) were promising candidates in reducing BP and thus, dietary intake could be recommended. Conversely, dietary intake of myristic acid (14:0), palmitic acid (16:0), and industrial trans FAs (iTFAs) should be restricted due to their association with elevated BP. Further research is warranted for pentadecanoic acid (15:0), heptadecanoic acid (17:0), stearic acid (18:0), alpha-linolenic acid (18:3n3), docosapentaenoic acid (22:5n3), linoleic acid (18:2n6), dihomo-gamma-linolenic acid (20:3n6), arachidonic acid (20:4n6), palmitoleic acid (16:1n7), and ruminant TFAs since their associations with BP present inconsistencies in the literature. Lifestyle factors such as dietary intake, physical activity, alcohol consumption and smoking should be considered when examining the relationship between FAs and BP. Overall, the FAs profile may contribute to BP level management; therefore, dietary recommendations are important.

Association between Serum Fatty Acids Profile and MetScore in Women with Severe Obesity

BACKGROUND

Metabolic syndrome (MetS) is a set of conditions associated with an increased cardiovascular risk. Several serum fatty acids (FAs) seem to play an essential role in the development of cardiometabolic diseases and mortality. Thus, it is imperative to explore the impact of FAs on MetS parameters, using an early MetS screening tool such as MetScore, which is readily available in clinical practice.

AIM

The aim of this study was to assess the potential correlation between serum FAs and cardiovascular risk using a MetScore.

METHODS

This cross-sectional study involved 41 women with severe obesity. The MetScore was calculated, and participants were categorized into high- and low-cardiovascular-risk groups based on the median MetScore value. Gas chromatography was used to quantify serum FAs. Generalized Linear Models were used to compare group means. The association was assessed through simple logistic regression, and an adjusted logistic regression was conducted to validate the association between Metscore and serum FAs.

RESULTS

The high-cardiovascular-risk group exhibited elevated values of HOMA-IR, palmitic, oleic, cis-vaccenic, and monounsaturated fatty acids, as well as the SCD-18C, indicating a heightened cardiovascular risk. Conversely, HDL-c, QUICK, gamma-linolenic, and eicosatetraenoic fatty acids showed lower values compared to the low-risk group.

CONCLUSIONS

Women with severe obesity and high cardiovascular risk have lower values of some omega-3 and omega-6 FAs, considered cardioprotective and anti-inflammatory, and have higher lipogenic activity and FAs, correlated with high cardiovascular risk. These findings emphasize the need to address lipid metabolism in this population as a therapeutic target to reduce cardiovascular risk. Future research should explore clinical interventions that modulate fatty acid metabolism to mitigate cardiometabolic complications.

Circulating fatty acids and risk of severe non-alcoholic fatty liver disease in the UK biobank: a prospective cohort of 116 223 individuals

Fatty acid (FA) metabolism plays an important role in the development of nonalcoholic fatty liver disease (NAFLD). However, data on the relationship between circulating FAs and NAFLD risk are limited. This study aims to assess the associations between specific circulating FAs and severe NAFLD risk among the general population. Overall 116 223 participants without NAFLD and other liver diseases from the UK Biobank were enrolled between 2006 and 2010 and were followed up until the end of 2021. Plasma concentrations of saturated fatty acids (SFAs), monounsaturated fatty acids (MUFAs), and polyunsaturated fatty acids (PUFAs) were analyzed using an NMR-based biomarker profiling platform. Hazard ratios (HRs) and 95% confidence intervals (CIs) of NAFLD risk were estimated using Cox proportional-hazard models adjusted for other potential confounders. During a mean follow-up of 12.3 years, we documented 1394 cases of severe NAFLD. After multivariate adjustment, plasma SFAs and MUFAs were associated with a higher risk of severe NAFLD, whereas plasma n-3 PUFAs, n-6 PUFAs, and linoleic acid (LA) were associated with a lower risk. As compared with the lowest quartile, HRs (95% CIs) of severe NAFLD risk in the highest quartiles were 1.85 (1.45-2.36) for SFAs, 1.74 (1.23-2.44) for MUFAs, 0.79 (0.65-0.97) for n-3 PUFAs, 0.68 (0.48-0.96) for n-6 PUFAs, and 0.73 (0.54-0.99) for LA. The significant relationships were mainly mediated by serum TG for SFAs, HDL-C for MUFAs and n-6 PUFAs, and C-reactive protein for n-3 PUFAs. Plasma SFAs were associated with a more pronounced increase in the risk of severe NAFLD among participants with fewer SFA-associated alleles (P interaction = 0.032). Dietary recommendations for reducing plasma SFAs and MUFAs while increasing n-3 and n-6 PUFAs may be protective for severe NAFLD, which could be mediated by lipid metabolism and inflammation.

Associations between dietary fatty acid and plasma fatty acid composition in non-alcoholic fatty liver disease: secondary analysis from a randomised trial with a hypoenergetic low-carbohydrate high-fat and intermittent fasting diet

Dietary fatty acids (FA) affect metabolic risk factors. The aim of this study was to explore if changes in dietary fat intake during energy restriction were associated with plasma FA composition. The study also investigated if these changes were associated with changes in liver fat, liver stiffness and plasma lipids among persons with non-alcoholic fatty liver disease. Dietary and plasma FA were investigated in patients with non-alcoholic fatty liver disease (n 48) previously enrolled in a 12-week-long open-label randomised controlled trial comparing two energy-restricted diets: a low-carbohydrate high-fat diet and intermittent fasting diet (5:2), to a control group. Self-reported 3 d food diaries were used for FA intake, and plasma FA composition was analysed using GC. Liver fat content and stiffness were measured by MRI and transient elastography. Changes in intake of total FA (r 0·41; P = 0·005), SFA (r 0·38; P = 0·011) and MUFA (r 0·42; P = 0·004) were associated with changes in liver stiffness. Changes in plasma SFA (r 0·32; P = 0·032) and C16 : 1n-7 (r 0·33; P = 0·028) were positively associated with changes in liver fat, while total n-6 PUFA (r -0·33; P = 0·028) and C20 : 4n-6 (r -0·42; P = 0·005) were inversely associated. Changes in dietary SFA, MUFA, cholesterol and C20:4 were positively associated with plasma total cholesterol and LDL-cholesterol. Modifying the composition of dietary fats during dietary interventions causes changes in the plasma FA profile in patients with non-alcoholic fatty liver disease. These changes are associated with changes in liver fat, stiffness, plasma cholesterol and TAG. Replacing SFA with PUFA may improve metabolic parameters in non-alcoholic fatty liver disease patients during weight loss treatment.

Excessive free fatty acid sensing in pituitary lactotrophs elicits steatotic liver disease by decreasing prolactin levels

The pituitary is the central endocrine gland with effects on metabolic dysfunction-associated steatotic liver disease (MASLD). However, it is not clear whether the pituitary responds to free fatty acid (FFA) toxicity, thus dysregulating hepatic lipid metabolism. Here, we demonstrate that decreased prolactin (PRL) levels are involved in the association between FFA and MASLD based on a liver biospecimen-based cohort. Moreover, overloaded FFAs decrease serum PRL levels, thus promoting liver steatosis in mice with both dynamic diet intervention and stereotactic pituitary FFA injection. Mechanistic studies show that excessive FFA sensing in pituitary lactotrophs inhibits the synthesis and secretion of PRL in a cell-autonomous manner. Notably, inhibiting excessive lipid uptake using pituitary stereotaxic virus injection or a specific drug delivery system effectively ameliorates hepatic lipid accumulation by improving PRL levels. Targeted inhibition of pituitary FFA sensing may be a potential therapeutic target for liver steatosis.

Immunometabolic Blood Biomarkers of Developmental Trajectories of Depressive Symptoms: Findings From the ALSPAC Birth Cohort

Studies of longitudinal trends of depressive symptoms in young people could provide insight into aetiologic mechanism, heterogeneity and origin of common cardiometabolic comorbidities for depression. Depression is associated with immunological and metabolic alterations, but immunometabolic characteristics of developmental trajectories of depressive symptoms remain unclear. Using depressive symptoms scores measured on 10 occasions between ages 10 and 25 years in the Avon Longitudinal Study of Parents and Children (n=7302), we identified four distinct trajectories: low-stable (70% of the sample), adolescent-limited (13%), adulthood-onset (10%) and adolescent-persistent (7%). We examined associations of these trajectories with: i) anthropometric, cardiometabolic and psychiatric phenotypes using multivariable regression (n=1709-3410); ii) 67 blood immunological proteins and 57 metabolomic features using empirical Bayes moderated linear models (n=2059 and n=2240 respectively); and iii) 28 blood cell counts and biochemical measures using multivariable regression (n=2256). Relative to the low-stable group, risk of depression and anxiety in adulthood was higher for all other groups, especially in the adolescent-persistent (ORdepression=22.80, 95% CI 15.25-34.37; ORGAD=19.32, 95% CI 12.86-29.22) and adulthood-onset (ORdepression=7.68, 95% CI 5.31-11.17; ORGAD=5.39, 95% CI 3.65-7.94) groups. The three depression-related trajectories vary in their immunometabolic profile, with evidence of little or no alterations in the adolescent-limited group. The adulthood-onset group shows widespread classical immunometabolic changes (e.g., increased immune cell counts and insulin resistance), while the adolescent-persistent group is characterised by higher BMI both in childhood and adulthood with few other immunometabolic changes. These findings point to distinct mechanisms and intervention opportunities for adverse cardiometabolic profile in different groups of young people with depression.

The associations of fatty acids related dietary patterns with overweight and obesity among Chinese children

BACKGROUND

Childhood overweight and obesity is becoming an emerging face of malnutrition. The aims of this study were to develop fatty acid (FAs) related dietary patterns and explored the associations of FAs related dietary patterns with overweight and obesity among Chinese children.

METHODS

An observational study was conducted on 435 children aged 4 to 7 years old in South Central China. Erythrocyte FAs composition was analyzed by gas chromatography-mass spectrometry. Diet was collected by food frequency questionnaires and dietary patterns were evaluated by reduced rank regression. The logistic regression analysis was used to exploring the association of dietary patterns with overweight and obesity.

RESULTS

The prevalence of overweight, obesity, and overweight or obesity were 6.52, 4.59, and 11.11% in Chinese children, respectively. Twenty five types of FAs were detected in erythrocyte of children and four FAs related dietary patterns were identified. The dietary pattern positively correlated with n-3 PUFAs, but negatively with SFAs,was characterized by high intake of fish, shrimp, crab and shellfish, leaf-off vegetable, nuts, and tubers, which have a significantly decreased overweight risk (OR = 0.580, 95%CI: 0.375 ∼ 0.895, P = 0.014).The pattern positively strong associated with n-6 PUFAs, but negatively strong with n-3 PUFAs, had high intake of snacks, leaf-off vegetable, fresh beans, and coarse cereals, which have a significantly decreased obesity risk (OR = 0.518, 95%CI: 0.325 ∼ 0.827, P = 0.006).

CONCLUSION

Four FAs related dietary patterns were identified. The dietary pattern with high intake of fish, shrimp, crab and shellfish decreased overweight risk by increasing n-3 PUFAs, and decreasing SFAs. The dietary pattern with high intake of plant food, decreased obesity risk by providing an balanced n-6/n-3 PUFAs ratio.

17β-Estradiol protects female rats from bilateral oophorectomy-induced nonalcoholic fatty liver disease induced by improving linoleic acid metabolism alteration and gut microbiota disturbance

After surgical or natural menopause, women face a high risk of nonalcoholic fatty liver disease (NAFLD), which can be diminished by hormone replacement therapy (HRT). The gut microbiota is subject to modulation by various physiological changes and the progression of diseases. This microbial ecosystem coexists symbiotically with the host, playing pivotal roles in immune maturation, microbial defense mechanisms, and metabolic functions essential for nutritional and hormone homeostasis. E2 supplementation effectively prevented the development of NAFLD after bilateral oophorectomy (OVX) in female rats. The changes in the gut microbiota such as abnormal biosynthetic metabolism of fatty acids caused by OVX were partially restored by E2 supplementation. The combination of liver transcriptomics and metabolomics analysis revealed that linoleic acid (LA) metabolism, a pivotal pathway in fatty acids metabolism was mainly manipulated during the induction and treatment of NAFLD. Further correlation analysis indicated that the gut microbes were associated with abnormal serum indicators and different LA metabolites. These metabolites are also closely related to serum indicators of NAFLD. An in vitro study verified that LA is an inducer of hepatic steatosis. The changes in transcription in the LA metabolism pathway could be normalized by E2 treatment. The metabolic perturbations of LA may directly and secondhand impact the development of NAFLD in postmenopausal individuals. This research focused on the sex-specific pathophysiology and treatment of NAFLD, providing more evidence for HRT and calling for the multitiered management of NAFLD.

Associations of diet quality and food consumption with serum biomarkers for lipid and amino acid metabolism in Finnish children: the PANIC study

PURPOSE

To investigate the associations of overall diet quality and dietary factors with serum biomarkers for lipid and amino acid metabolism in a general population of children.

METHODS

We studied 194 girls and 209 boys aged 6-8 years participating in the Physical Activity and Nutrition in Children study. Food consumption was assessed by 4-day food records and diet quality was quantified by the Finnish Children Healthy Eating Index (FCHEI). Fasting serum fatty acids, amino acids, apolipoproteins, as well as lipoprotein particle sizes were analyzed with high-throughput nuclear magnetic resonance spectroscopy. Data were analyzed using linear regression adjusted for age, sex, and body fat percentage.

RESULTS

FCHEI was directly associated with the ratio of polyunsaturated (PUFA) to saturated fatty acids (SFA) (PUFA/SFA), the ratio of PUFA to monounsaturated fatty acids (MUFA) (PUFA/MUFA), the ratio of PUFA to total fatty acids (FA) (PUFA%), the ratio of omega-3-fatty acids to total FA (omega-3 FA%), and inversely associated with the ratio of MUFA to total FA (MUFA%), alanine, glycine, histidine and very-low density lipoprotein (VLDL) particle size. Consumption of vegetable oils and vegetable-oil-based margarine (≥ 60% fat) was directly associated with PUFA/SFA, PUFA/MUFA, PUFA%, the ratio of omega-6 FA to total FA (omega-6 FA%), and inversely associated with SFA, MUFA, SFA to total FA (SFA%), MUFA%, alanine and VLDL particle size. Consumption of high-fiber grain products directly associated with PUFA/SFA, PUFA/MUFA, omega-3 FA%, omega-6 FA%, PUFA% and inversely associated with SFA and SFA%. Fish consumption directly related to omega-3 FA and omega-3 FA%. Consumption of sugary products was directly associated with histidine and VLDL particle size. Vegetable, fruit, and berry consumption had direct associations with VLDL particle size and the ratio of apolipoprotein B to apolipoprotein A1. Consumption of low fat (< 1%) milk was directly associated with phenylalanine. A higher consumption of high-fat (≥ 1%) milk was associated with lower serum MUFA/SFA and higher SFA%. Sausage consumption was directly related to SFA% and histidine. Red meat consumption was inversely associated with glycine.

CONCLUSIONS

Better diet quality, higher in intake of dietary sources of unsaturated fat and fiber, and lower in sugary product intake were associated with more favorable levels of serum biomarkers for lipid and amino acid metabolism independent of adiposity.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT01803776, registered March 3, 2013.

Metabolomic Profiles of Nonobese and Obese Women With Gestational Diabetes

CONTEXT

In non-pregnant population, nonobese individuals with obesity-related metabolome have increased risk for type 2 diabetes and cardiovascular diseases. The risk of these diseases is also increased after gestational diabetes.

OBJECTIVE

This work aimed to examine whether nonobese (body mass index [BMI] < 30) and obese (BMI ≥ 30) women with gestational diabetes mellitus (GDM) and obese non-GDM women differ in metabolomic profiles from nonobese non-GDM controls.

METHODS

Levels of 66 metabolic measures were assessed in early (median 13, IQR 12.4-13.7 gestation weeks), and across early, mid (20, 19.3-23.0), and late (28, 27.0-35.0) pregnancy blood samples in 755 pregnant women from the PREDO and RADIEL studies. The independent replication cohort comprised 490 pregnant women.

RESULTS

Nonobese and obese GDM, and obese non-GDM women differed similarly from the controls across early, mid, and late pregnancy in 13 measures, including very low-density lipoprotein-related measures, and fatty acids. In 6 measures, including fatty acid (FA) ratios, glycolysis-related measures, valine, and 3-hydroxybutyrate, the differences between obese GDM women and controls were more pronounced than the differences between nonobese GDM or obese non-GDM women and controls. In 16 measures, including HDL-related measures, FA ratios, amino acids, and inflammation, differences between obese GDM or obese non-GDM women and controls were more pronounced than the differences between nonobese GDM women and controls. Most differences were evident in early pregnancy, and in the replication cohort were more often in the same direction than would be expected by chance alone.

CONCLUSION

Differences between nonobese and obese GDM, or obese non-GDM women and controls in metabolomic profiles may allow detection of high-risk women for timely targeted preventive interventions.

Antihypertensive effects of Nigella sativa supplementation: An updated systematic review and meta-analysis of randomized controlled trials

Clinical studies have suggested that Nigella Sativa (N. sativa) supplementation may effectively reduce blood pressure, but the findings are controversial. Therefore, this study aimed to examine the effects of N. sativa on blood pressure in adults. PubMed, Cochrane Library, Web of Science, Scopus, Embase databases, and Google Scholar were searched till August 2022. To analyze weighted mean differences (WMDs), a random-effects model was utilized. Nonlinear dose-response analysis and a meta-regression were conducted. N. sativa supplementation was effective in reducing both systolic (WMD: -3.06 mmHg; 95% CI: -3.89 to -2.22, p < 0.001; I2  = 84.7%, p < 0.001) and diastolic blood pressure (WMD = -2.69 mmHg; 95% CI: -3.72, -1.66, p < 0.001; I2  = 97.3%, p < 0.001). The current meta-analysis suggests that N. sativa supplementation can improve blood pressure and claims that N. sativa could be used as an effective approach to blood pressure management.

Associations of specific dietary unsaturated fatty acids with risk of overweight/obesity: population-based cohort study

Background

The role of specific unsaturated fatty acids (FAs) in the development of overweight/obesity remains unclear in the general population. Here, we aimed to explore the associations of different types of unsaturated FAs with overweight/obesity risk among the Chinese population.

Methods

Eight thousand seven hundred forty-two subjects free of overweight/obesity at entry in the China Health and Nutrition Survey (CHNS) were followed up until 2015. Dietary unsaturated FAs were assessed by 3-day 24-h recalls with a weighing method in each wave. Cox regression models were used to obtain the hazard ratios (HRs) and 95% confidence intervals (CIs) for overweight/obesity risk associated with unsaturated FAs.

Results

During a median follow-up of 7 years, 2,753 subjects (1,350 males and 1,403 females) developed overweight/obesity. Consuming more monounsaturated FAs (MUFAs) was associated with a lower risk of overweight/obesity (highest vs. lowest quartile: HR 0.80, 95% CI 0.67-0.96; P-trend = 0.010). Similar inverse associations were observed for plant-MUFAs (HR_Q4vsQ1 0.83, 95% CI: 0.73-0.94; P-trend = 0.003) and animal-MUFAs (HR_Q4vsQ1 0.77, 95% CI: 0.64-0.94; P-trend = 0.004), total dietary oleic acid (OA) (HR_Q4vsQ1 0.66, 95% CI: 0.55-0.79; P-trend <0.001), plant-OA (HR_Q4vsQ1 0.73, 95% CI: 0.64-0.83; P-trend <0.001) and animal-OA (HR_Q4vsQ1 0.68, 95% CI: 0.55-0.84; P-trend <0.001). In addition, the intakes of n-3 polyunsaturated FAs (PUFAs) (HR_Q4vsQ1 1.24, 95% CI: 1.09-1.42; P-trend = 0.017) and α-linolenic acid (ALA) (HR_Q4vsQ1 1.22, 95% CI: 1.07-1.39; P-trend = 0.039) but not marine n-3 PUFAs were positively linked to overweight/obesity risk. Consumption of n-6 PUFAs (HR_Q4vsQ1 1.13, 95% CI: 0.99-1.28; P-trend = 0.014) and linoleic acid (LA) (HR_Q4vsQ1 1.11, 95% CI: 0.98-1.26; P-trend = 0.020) had marginal and positive relationships with the incidence of overweight/obesity. N-6/n-3 PUFA ratio ranging from 5.7 to 12.6 was related to higher risk of overweight/obesity.

Conclusion

Higher dietary intake of MUFAs was associated with lower overweight/obesity risk, which was mainly driven by dietary OA from either plant or animal sources. Intakes of ALA, n-6 PUFAs and LA were related to higher risk of overweight/obesity. These results support consuming more MUFAs for maintaining a healthy body weight among the Chinese population.

Fatty Acid Profile and Genetic Variants of Proteins Involved in Fatty Acid Metabolism Could Be Considered as Disease Predictor

Circulating fatty acids (FA) have an endogenous or exogenous origin and are metabolized under the effect of many enzymes. They play crucial roles in many mechanisms: cell signaling, modulation of gene expression, etc., which leads to the hypothesis that their perturbation could be the cause of disease development. FA in erythrocytes and plasma rather than dietary FA could be used as a biomarker for many diseases. Cardiovascular disease was associated with elevated trans FA and decreased DHA and EPA. Increased arachidonic acid and decreased Docosahexaenoic Acids (DHA) were associated with Alzheimer's disease. Low Arachidonic acid and DHA are associated with neonatal morbidities and mortality. Decreased saturated fatty acids (SFA), increased monounsaturated FA (MUFA) and polyunsaturated FA (PUFA) (C18:2 n-6 and C20:3 n-6) are associated with cancer. Additionally, genetic polymorphisms in genes coding for enzymes implicated in FA metabolism are associated with disease development. FA desaturase (FADS1 and FADS2) polymorphisms are associated with Alzheimer's disease, Acute Coronary Syndrome, Autism spectrum disorder and obesity. Polymorphisms in FA elongase (ELOVL2) are associated with Alzheimer's disease, Autism spectrum disorder and obesity. FA-binding protein polymorphism is associated with dyslipidemia, type 2 diabetes, metabolic syndrome, obesity, hypertension, non-alcoholic fatty liver disease, peripheral atherosclerosis combined with type 2 diabetes and polycystic ovary syndrome. Acetyl-coenzyme A carboxylase polymorphisms are associated with diabetes, obesity and diabetic nephropathy. FA profile and genetic variants of proteins implicated in FA metabolism could be considered as disease biomarkers and may help with the prevention and management of diseases.

A protein-lipid complex that detoxifies free fatty acids

Fatty acids (FAs) are well known to serve as substrates for reactions that provide cells with membranes and energy. In contrast to these metabolic reactions, the physiological importance of FAs themselves known as free FAs (FFAs) in cells remains obscure. Since accumulation of FFAs in cells is toxic, cells must develop mechanisms to detoxify FFAs. One such mechanism is to sequester free polyunsaturated FAs (PUFAs) into a droplet-like structure assembled by Fas-Associated Factor 1 (FAF1), a cytosolic protein. This sequestration limits access of PUFAs to Fe2+ , thereby preventing Fe2+ -catalyzed PUFA peroxidation. Consequently, assembly of the FAF1-FFA complex is critical to protect cells from ferroptosis, a cell death pathway triggered by PUFA peroxidation. The observations that free PUFAs in cytosol are not randomly diffused but rather sequestered into a membraneless complex should open new directions to explore signaling pathways by which FFAs regulate cellular physiology.

Fatty acid correlations with HOMA-IR and HOMA-% β are differentially dictated by their serum free and total pools and flaxseed oil supplementation

Objective. The intent of the present study was to test two hypotheses. The primary hypothesis was that there would be differences between blood serum individual free fatty acids (SIFFA) and serum individual total fatty acids (SITFA) in terms of their different relationships (correlations) to each of homeostatic model assessment-individual insulin resistance (HOMA-IR) and homeostatic model assessment-individual insulin resistance-percentage β-cell function (HOMA-% β) remaining in human type 2 diabetic patients with pre-flaxseed oil (FXO) and pre-safflower oil (SFO) administration. The secondary hypothesis was that FXO (rich in alpha-linolenic acid, ALA) supplementation would alter these correlations differently in the SIFFA and STIFFA pools in comparison with the placebo SFO (poor in ALA). Methods. Patients were recruited via a newspaper advertisement and two physicians. All patients came to visit 1 and three months later to visit 2. At visit 2, the subjects were randomly assigned (double-blind) to flaxseed or safflower oil (placebo) treatment for three months until visit 3. Results. There were pre-intervention differences in the SIFFA and STIFA pool's relationships with each of HOMA-IR and HOMA-% β. These relatioships remained either unchanged or became significant after intervention (treatment or placebo). There was a negative correlation found between HOMA-IR and serum free ALA (SFALA) mol % after FXO. Serum total ALA (STALA) mol % had no significant correlations with HOMA-IR and HOMA- % β before and after flaxseed oil administration. Conclusions. The SIFFA and SITFA pools have different relationships with HOMA-IR and HOMA-% β for each of pre- and post-intervention. It is concluded that the data support both the primary and the secondary hypotheses indicating that they are correct.

Risk Prediction Models and Novel Prognostic Factors for Heart Failure with Preserved Ejection Fraction: A Systematic and Comprehensive Review

BACKGROUND

Patients with heart failure with preserved ejection fraction (HFpEF) have large individual differences, unclear risk stratification, and imperfect treatment plans. Risk prediction models are helpful for the dynamic assessment of patients' prognostic risk and early intensive therapy of high-risk patients. The purpose of this study is to systematically summarize the existing risk prediction models and novel prognostic factors for HFpEF, to provide a reference for the construction of convenient and efficient HFpEF risk prediction models.

METHODS

Studies on risk prediction models and prognostic factors for HFpEF were systematically searched in relevant databases including PubMed and Embase. The retrieval time was from inception to February 1, 2023. The Quality in Prognosis Studies (QUIPS) tool was used to assess the risk of bias in included studies. The predictive value of risk prediction models for end outcomes was evaluated by sensitivity, specificity, the area under the curve, C-statistic, C-index, etc. In the literature screening process, potential novel prognostic factors with high value were explored.

RESULTS

A total of 21 eligible HFpEF risk prediction models and 22 relevant studies were included. Except for 2 studies with a high risk of bias and 2 studies with a moderate risk of bias, other studies that proposed risk prediction models had a low risk of bias overall. Potential novel prognostic factors for HFpEF were classified and described in terms of demographic characteristics (age, sex, and race), lifestyle (physical activity, body mass index, weight change, and smoking history), laboratory tests (biomarkers), physical inspection (blood pressure, electrocardiogram, imaging examination), and comorbidities.

CONCLUSION

It is of great significance to explore the potential novel prognostic factors of HFpEF and build a more convenient and efficient risk prediction model for improving the overall prognosis of patients. This review can provide a substantial reference for further research.

The Effect of Dietary Carbohydrate and Fat Manipulation on the Metabolome and Markers of Glucose and Insulin Metabolism: A Randomised Parallel Trial

High carbohydrate, lower fat (HCLF) diets are recommended to reduce cardiometabolic disease (CMD) but low carbohydrate high fat (LCHF) diets can be just as effective. The effect of LCHF on novel insulin resistance biomarkers and the metabolome has not been fully explored. The aim of this study was to investigate the impact of an ad libitum 8-week LCHF diet compared with a HCLF diet on CMD markers, the metabolome, and insulin resistance markers. n = 16 adults were randomly assigned to either LCHF (n = 8, <50 g CHO p/day) or HCLF diet (n = 8) for 8 weeks. At weeks 0, 4 and 8, participants provided fasted blood samples, measures of body composition, blood pressure and dietary intake. Samples were analysed for markers of cardiometabolic disease and underwent non-targeted metabolomic profiling. Both a LCHF and HCLF diet significantly (p < 0.01) improved fasting insulin, HOMA IR, rQUICKI and leptin/adiponectin ratio (p < 0.05) levels. Metabolomic profiling detected 3489 metabolites with 78 metabolites being differentially regulated, for example, an upregulation in lipid metabolites following the LCHF diet may indicate an increase in lipid transport and oxidation, improving insulin sensitivity. In conclusion, both diets may reduce type 2 diabetes risk albeit, a LCHF diet may enhance insulin sensitivity by increasing lipid oxidation.

Associations of serum n-3 and n-6 polyunsaturated fatty acids with prevalence and incidence of nonalcoholic fatty liver disease

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is a major cause of liver diseases worldwide, and lifestyle and diet are significant factors in its development. Recent studies have suggested that dietary fat quality is associated with the development of NAFLD.

OBJECTIVES

Our purpose was to investigate the cross-sectional and longitudinal associations of serum n-3 (ω-3) and n-6 (ω-6) PUFAs with NAFLD among middle-aged and older men and women from eastern Finland. We also investigated the associations of estimated Δ5-desaturase and Δ6-desaturase activities, enzymes involved in PUFA metabolism, with NAFLD.

METHODS

After exclusions, the cross-sectional analyses included 1533 men examined in 1984-1989 and 674 men and 870 women examined in 1998-2001 in the Kuopio Ischaemic Heart Disease Risk Factor Study. The longitudinal analyses included 520 men examined in 1991-1993 and 301 men and 466 women examined in 2005-2008. Fatty liver index (FLI) was used as a surrogate for NAFLD. Hepatic steatosis was defined as FLI >60. ANCOVA and logistic regression were used for analyses.

RESULTS

In the longitudinal analyses, participants with higher serum concentrations of total n-6 PUFA and linoleic acid, the major n-6 PUFA, had markedly lower FLI and lower odds for hepatic steatosis (e.g., odds ratios for incident hepatic steatosis in the highest compared with lowest quartiles were ≤0.41), whereas serum γ-linolenic acid concentration was associated with a higher FLI and higher odds for hepatic steatosis. The associations with the other PUFAs were generally weaker and nonsignificant. In the cross-sectional analyses, also the long-chain n-3 PUFAs had inverse associations. In most analyses, high estimated Δ5-desaturase activity was associated with lower risk and high estimated Δ6-desaturase activity with higher risk for NAFLD.

CONCLUSIONS

In middle-aged and older Finnish adults, higher serum concentrations of total n-6 PUFAs and linoleic acid were associated with lower odds for future NAFLD.

Broader and safer clinically-relevant activities of pentadecanoic acid compared to omega-3: Evaluation of an emerging essential fatty acid across twelve primary human cell-based disease systems

A growing body of evidence supports that pentadecanoic acid (C15:0), an odd-chain saturated fat found in butter, is an essential fatty acid that is necessary in the diet to support long-term metabolic and heart health. Here, dose dependent and clinically relevant cell-based activities of pure C15:0 (FA15TM) were compared to eicosapentaenoic acid (EPA), a leading omega-3 fatty acid, as well as to an additional 4,500 compounds. These studies included 148 clinically relevant biomarkers measured across 12 primary human cell systems, mimicking various disease states, that were treated with C15:0 at four different concentrations (1.9 to 50 μM) and compared to non-treated control systems. C15:0 was non-cytotoxic at all concentrations and had dose dependent, broad anti-inflammatory and antiproliferative activities involving 36 biomarkers across 10 systems. In contrast, EPA was cytotoxic to four cell systems at 50 μM. While 12 clinically relevant activities were shared between C15:0 and EPA at 17 μM, C15:0 had an additional 28 clinically relevant activities, especially anti-inflammatory, that were not present in EPA. Further, at 1.9 and 5.6 μM, C15:0 had cell-based properties similar to bupropion (Pearson’s scores of 0.78), a compound commonly used to treat depression and other mood disorders. At 5.6 μM, C15:0 mimicked two antimicrobials, climabazole and clarithromycin (Pearson’s scores of 0.76 and 0.75, respectively), and at 50 μM, C15:0 activities matched that of two common anti-cancer therapeutics, gemcitabine and paclitaxel (Pearson’s scores of 0.77 and 0.74, respectively). In summary, C15:0 had dose-dependent and clinically relevant activities across numerous human cell-based systems that were broader and safer than EPA, and C15:0 activities paralleled common therapeutics for mood disorders, microbial infections, and cancer. These studies further support the emerging role of C15:0 as an essential fatty acid.

Serum Levels of Free Fatty Acids in Obese Mice and Their Associations with Routine Lipid Profiles

PURPOSE

To investigate serum levels of free fatty acids (FFAs) and their associations with routine serum lipids in diet-induced obese mice, which have been scantily reported before.

METHODS

Male C57BL/6 J mice were fed high-fat diets for 12 weeks to induce obesity. Levels of serum FFAs were measured by ultra-performance liquid chromatography-electrospray ionization-tandem mass spectrometry.

RESULTS

Obese mice had higher serum levels of total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C), but lower triglycerides (TG) than control mice. A total of 30 FFAs were found, and 3 saturated fatty acids (SFAs), all 8 monounsaturated fatty acids (MUFAs) and 7 polyunsaturated fatty acids (PUFAs) decreased in obese mice, but one SFA (C4:0) increased. Differences in the relative levels of individual FFAs to total FFAs, SFAs, MUFAs or PUFAs between obese and control mice were different from each other and from those evaluated by concrete levels except C4:0, C16:1, C19:1 and C18:4. Only the concrete levels of C4:0, C22:3 and C18:4 were associated with routine serum lipids, including C22:3 negatively with TG in control mice, and C4:0 and C18:4 positively with LDL-C in obese mice, although the relative levels of C4:0 to total MUFAs negatively with TC, and C23:3 to total SFAs or MUFAs negatively with TG in control mice. Different relative levels of the remaining FFAs were differently associated with different routine serum lipids in obese and/or control mice.

CONCLUSION

Obesity may influence serum FFAs profiles. The relationship of individual FFAs and their relative levels to other FFAs with routine serum lipids in obese and control mice suggests that individual FFAs may interact with others and obesity on levels of routine serum lipids. Once confirmed, the interactions may be novel perspectives when fatty acids are used to improve hyperlipidemia in the subjects with obesity.