Polyunsaturated fatty acids and type 2 diabetes: Impact on the glycemic control mechanism

Serum bile acid and unsaturated fatty acid profiles of non-alcoholic fatty liver disease in type 2 diabetic patients

BACKGROUND

The understanding of bile acid (BA) and unsaturated fatty acid (UFA) profiles, as well as their dysregulation, remains elusive in individuals with type 2 diabetes mellitus (T2DM) coexisting with non-alcoholic fatty liver disease (NAFLD). Investigating these metabolites could offer valuable insights into the pathophy-siology of NAFLD in T2DM.

AIM

To identify potential metabolite biomarkers capable of distinguishing between NAFLD and T2DM.

METHODS

A training model was developed involving 399 participants, comprising 113 healthy controls (HCs), 134 individuals with T2DM without NAFLD, and 152 individuals with T2DM and NAFLD. External validation encompassed 172 participants. NAFLD patients were divided based on liver fibrosis scores. The analytical approach employed univariate testing, orthogonal partial least squares-discriminant analysis, logistic regression, receiver operating characteristic curve analysis, and decision curve analysis to pinpoint and assess the diagnostic value of serum biomarkers.

RESULTS

Compared to HCs, both T2DM and NAFLD groups exhibited diminished levels of specific BAs. In UFAs, particular acids exhibited a positive correlation with NAFLD risk in T2DM, while the ω-6:ω-3 UFA ratio demonstrated a negative correlation. Levels of α-linolenic acid and γ-linolenic acid were linked to significant liver fibrosis in NAFLD. The validation cohort substantiated the predictive efficacy of these biomarkers for assessing NAFLD risk in T2DM patients.

CONCLUSION

This study underscores the connection between altered BA and UFA profiles and the presence of NAFLD in individuals with T2DM, proposing their potential as biomarkers in the pathogenesis of NAFLD.

A review on associated factors and management measures for sarcopenia in type 2 diabetes mellitus

Type 2 diabetes mellitus (T2DM) is a chronic metabolic disease characterized by hyperglycemia, insulin resistance, and insufficient insulin secretion. Sarcopenia, as a new complication of diabetes, is characterized by the loss of muscle mass and the progressive decline of muscle strength and function in T2DM patients, which has a serious impact on the physical and mental health of patients. Insulin resistance, mitochondrial dysfunction, and chronic inflammation are common mechanisms of diabetes and sarcopenia. Reasonable exercise training, nutrition supplement, and drug intervention may improve the quality of life of patients with diabetes combined with sarcopenia. This article reviews the relevant factors and management measures of sarcopenia in T2DM patients, in order to achieve early detection, diagnosis, and intervention.

Epigenome-wide association study of dietary fatty acid intake

BACKGROUND

Dietary intake of n-3 polyunsaturated fatty acids (PUFA) may have a protective effect on the development of cardiovascular diseases, diabetes, depression and cancer, while a high intake of n-6 PUFA was often reported to be associated with inflammation-related traits. The effect of PUFAs on health outcomes might be mediated by DNA methylation (DNAm). The aim of our study is to identify the impact of PUFA intake on DNAm in the Cooperative Health Research in the Region of Augsburg (KORA) FF4 cohort and the Leiden Longevity Study (LLS).

RESULTS

DNA methylation levels were measured in whole blood from the population-based KORA FF4 study (N = 1354) and LLS (N = 448), using the Illumina MethylationEPIC BeadChip and Illumina HumanMethylation450 array, respectively. We assessed associations between DNAm and intake of eight and four PUFAs in KORA and LLS, respectively. Where possible, results were meta-analyzed. Below the Bonferroni correction threshold (p < 7.17 × 10-8), we identified two differentially methylated positions (DMPs) associated with PUFA intake in the KORA study. The DMP cg19937480, annotated to gene PRDX1, was positively associated with docosahexaenoic acid (DHA) in model 1 (beta: 2.00 × 10-5, 95%CI: 1.28 × 10-5-2.73 × 10-5, P value: 6.98 × 10-8), while cg05041783, annotated to gene MARK2, was positively associated with docosapentaenoic acid (DPA) in our fully adjusted model (beta: 9.80 × 10-5, 95%CI: 6.25 × 10-5-1.33 × 10-4, P value: 6.75 × 10-8). In the meta-analysis, we identified the CpG site (cg15951061), annotated to gene CDCA7L below Bonferroni correction (1.23 × 10-7) associated with eicosapentaenoic acid (EPA) intake in model 1 (beta: 2.00 × 10-5, 95% CI: 1.27 × 10-5-2.73 × 10-5, P value = 5.99 × 10-8) and we confirmed the association of cg19937480 with DHA in both models 1 and 2 (beta: 2.07 × 10-5, 95% CI: 1.31 × 10-5-2.83 × 10-5, P value = 1.00 × 10-7 and beta: 2.19 × 10-5, 95% CI: 1.41 × 10-5-2.97 × 10-5, P value = 5.91 × 10-8 respectively).

CONCLUSIONS

Our study identified three CpG sites associated with PUFA intake. The mechanisms of these sites remain largely unexplored, highlighting the novelty of our findings. Further research is essential to understand the links between CpG site methylation and PUFA outcomes.

Association between type 2 diabetes and different types of dietary fats: A case-control study

BACKGROUND

The effect of dietary fats on type 2 diabetes (T2D) is not clear. This study aimed to determine the association between T2D and dietary fatty acids among Iranian adults.

METHODS

This case-control study was performed on 4241 participants aged 35-70, including 1804 people with T2D and pre-diabetes as the case group and 2437 people without diabetes as the control group. Dietary intake was assessed using a food frequency questionnaire (FFQ).

RESULTS

The cases had higher age (48.36 ± 8.62 vs. 54.53 ± 7.75 y, P < 0.001), weight (73.7713.41 vs. 76.18 ± 13.49 kg, P = 0.001), body mass index (BMI) (28.02 ± 4.70 vs. 24 ± 4.74 kg/m2, P = 0.001), right systolic blood pressure (RSBP) (113.33 ± 16.7 vs. 121.61 ± 17.24 mmHg, P = 0.001), right diastolic blood pressure (RDBP) (71.41 ± 10.53 vs. 75.33 ± 9.92 mmHg, P = 0.001), fasting blood sugar (FBS) (96.87 ± 19.39 vs. 169.95 ± 69.28 mg/dl, P = 0.001), blood urine nitrogen (BUN) (13.65 ± 3.74 vs. 14.26 ± 4.03 mg/dl, P = 0.001), triglyceride (TG) (141.61 ± 99.37 vs. 175.96 ± 114.74 mg/dl, P = 0.001), alkaline phosphatase (ALP) (218.24 ± 66.35 vs. 246.97 ± 72.65 IU/L, P = 0.001), low-density lipoprotein cholesterol (LDL) (111.68 ± 33.02 vs. 101.97 ± 36.54 mg/dl, P = 0.001), serum glutamic-pyruvic transaminase (SGPT) (21.88 ± 15.15 vs. 23.55 ± 15.96 IU/L, P = 0.001), gamma-glutamyl transferase (GGT) (24.66 ± 20.42 vs. 30.72 ± 30.43 IU/L P = 0.001), and cholesterol (192.45 ± 39.1190 vs. 187.12 ± 46.19 mg/dl P = 0.001) compared to the control group. T2D was negatively associated with dietary intake of PUFAs (OR = 0.93, CI95%:0.84-1.03, P = 0.01) and positively associated with dietary cholesterol (OR: 1.01, CI95%:1.001-1.01, P = 0.02).

CONCLUSION

In summary, cholesterol was positively and PUFAs were negatively associated with diabetes. If the results of the present study on the effect of fat intake on diabetes are proven, future dietary recommendations for people at risk of diabetes may be corrected by providing diets rich in polyunsaturated fatty acids and low in cholesterol.

Discovery of new DHA ethanolamine derivatives as potential anti-inflammatory agents targeting Nur77

Docosahexaenoic acid (DHA) has a strong anti-inflammatory effect and is reported to bind to the ligand-binding domain (LBD) of the anti-inflammatory modulator Nur77. Recently, we have found that DHA ethanolamine (DHA-EA) exerts anti-inflammatory activity as a Nur77 modulator. Herein, using a fragment splicing-based drug design strategy, nineteen new DHA-EA derivatives were synthesized starting from DHA algae oil and then evaluated for their anti-inflammatory activity. The cell-based cytotoxicity assays showed that compounds J2, J9, and J18 had no noticeable effect on the cell morphology and viability of RAW 264.7, LO2, and MCR-5 cells. Meanwhile, J9 was identified as the most potent anti-inflammatory molecule in LPS-stimulated RAW 264.7 cells. Also, the molecular docking study and SPR assay demonstrated that J9 exhibited in vitro Nur77-binding affinity (KD = 8.58 × 10-6 M). Moreover, the mechanism studies revealed that the anti-inflammatory activity of J9 was associated with its inhibition of NF-κB activation in a Nur77-dependent manner. Notably, J9 could attenuate LPS-induced inflammation in the mouse acute lung injury (ALI) model. Overall, the DHA-EA derivative J9 targeting Nur77 is a potential candidate for developing anti-inflammatory and ALI-treating agents.

Dietary pro-oxidant score (POS) and cardio-metabolic panel among obese individuals: a cross-sectional study

BACKGROUND

Oxidative stress is a disturbance in the natural balance between oxidative and anti-oxidative processes, which is the major effective factor in cardiovascular disorders and metabolic syndrome (MetS), due to the role of pro-oxidants in inducing oxidative stress, and as a result, the occurrence and exacerbation of components of metabolic syndrome and cardiovascular risk factors, this cross-sectional study was conducted with the aim of investigating the relationship between the status of dietary pro-oxidants score (POS) and metabolic parameters including serum lipids, glycemic markers and blood pressure among obese adults.

METHODS

338 individuals with obesity (BMI ≥ 30 kg/m ²), aged between 20 and 50 years were recruited in the present cross-sectional study. A validated food frequency questionnaire (FFQ) was used to determine the dietary pro-oxidant score (POS). Analysis of variance (ANOVA) with Tukey's post-hoc comparisons after adjustment for confounders and multivariable logistic regression analysis were performed to determine the association of cardiometabolic risk factors among the tertiles of POS.

RESULTS

Participants with higher POS had lower levels of body mass index (BMI), weight and waist circumference (WC). There were no significant associations between metabolic parameters including glycemic markers and lipid profile in one-way ANOVA and multivariate multinomial logistic regression models.

CONCLUSIONS

The findings of this study revealed that greater dietary pro-oxidant intake might be associated with lower BMI, body weight, and WC in Iranian obese individuals. Further studies with interventional or longitudinal approaches will help to better elucidate the causality of the observed associations.

Sex-specific responses in glucose-insulin homeostasis and lipoprotein-lipid components after high-dose supplementation with marine n-3 PUFAs in abdominal obesity: a randomized double-blind crossover study

Background

Clinical studies on effects of marine-derived omega-3 (n-3) polyunsaturated fatty acids (PUFAs), mainly eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), and the plant-derived omega-6 (n-6) PUFA linoleic acid (LA) on lipoprotein-lipid components and glucose-insulin homeostasis have shown conflicting results, which may partly be explained by differential responses in females and males. However, we have lacked data on sexual dimorphism in the response of cardiometabolic risk markers following increased consumption of n-3 or n-6 PUFAs.

Objective

To explore sex-specific responses after n-3 (EPA + DHA) or n-6 (LA) PUFA supplementation on circulating lipoprotein subfractions, standard lipids, apolipoproteins, fatty acids in red blood cell membranes, and markers of glycemic control/insulin sensitivity among people with abdominal obesity.

Methods

This was a randomized double-blind crossover study with two 7-week intervention periods separated by a 9-week washout phase. Females (n = 16) were supplemented with 3 g/d of EPA + DHA (fish oil) or 15 g/d of LA (safflower oil), while males (n = 23) received a dose of 4 g/d of EPA + DHA or 20 g/d of LA. In fasting blood samples, we measured lipoprotein particle subclasses, standard lipids, apolipoproteins, fatty acid profiles, and markers of glycemic control/insulin sensitivity.

Results

The between-sex difference in relative change scores was significant after n-3 for total high-density lipoproteins (females/males: -11%*/-3.3%, p = 0.036; *: significant within-sex change), high-density lipoprotein particle size (+2.1%*/-0.1%, p = 0.045), and arachidonic acid (-8.3%*/-12%*, p = 0.012), and after n-6 for total (+37%*/+2.1%, p = 0.041) and small very-low-density lipoproteins (+97%*/+14%, p = 0.021), and lipoprotein (a) (-16%*/+0.1%, p = 0.028). Circulating markers of glucose-insulin homeostasis differed significantly after n-3 for glucose (females/males: -2.1%/+3.9%*, p = 0.029), insulin (-31%*/+16%, p < 0.001), insulin C-peptide (-12%*/+13%*, p = 0.001), homeostasis model assessment of insulin resistance index 2 (-12%*/+14%*, p = 0.001) and insulin sensitivity index 2 (+14%*/-12%*, p = 0.001), and quantitative insulin sensitivity check index (+4.9%*/-3.4%*, p < 0.001).

Conclusion

We found sex-specific responses after high-dose n-3 (but not n-6) supplementation in circulating markers of glycemic control/insulin sensitivity, which improved in females but worsened in males. This may partly be related to the sex differences we observed in several components of the lipoprotein-lipid profile following the n-3 intervention.

Clinical trial registration

https://clinicaltrials.gov/, identifier [NCT02647333].

Blood indices of omega-3 and omega-6 polyunsaturated fatty acids are altered in hyperglycemia

Polyunsaturated fatty acids (PUFAs) may favorably influence the risk and clinical course of diabetes mellitus (DM). In particular, eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and arachidonic acid (AA) alleviate oxidative injury and insulin resistance characteristic of DM. Uncertainty still remains, however, as to the composition and proportions of blood PUFAs in relation to fasting blood glucose levels. This study, thus, aims to examine the patterns of blood PUFA indices in normoglycemic (NG) and hyperglycemic (HG) Saudi subjects. Age, gender, FA profiles, and laboratory records of 143 subjects collected from September 2014 to March 2018 were retrospectively analyzed. Means, prevalence rates, associations, risk measures, and the diagnostic accuracy of PUFAs were determined. HG subjects had significantly lower AA (0.70%, 95% CI: 0.59-0.80% vs 0.46%, 95% CI: 0.38-0.53%) and higher EPA/AA ratio (0.36, 95% CI: 0.30-0.42 vs 0.69, 95% CI: 0.61-0.77). Gender-wise comparisons revealed that ώ-6/ώ-3 ratio was the only PUFA index significantly elevated in HG males (0.36, 95% CI: 0.26-0.45 vs 5.68, 95% CI: 4.98-6.38) while both DHA (2.91%, 95% CI: 2.54-3.29% vs 3.37%, 95% CI: 3.13-3.60%) and ώ-3 index (3.1%, 95% CI: 2.70-3.49% vs 3.63%, 95% CI: 3.38-3.88%) were significantly elevated in HG females. Furthermore, reduced AA and elevated EPA/AA ratio were more prevalent in HG subjects (26.53 vs 28.72 and 30.61 vs 38.29, respectively) and exhibited the highest diagnostic accuracy for HG among all PUFA indices. Altogether, our study revealed that distinct, gender-specific blood PUFA indices are differentially regulated in HG subjects which may be valuable for DM management.

Type 2 Diabetes and Alzheimer's Disease: The Emerging Role of Cellular Lipotoxicity

Type 2 diabetes (T2D) and Alzheimer's diseases (AD) represent major health issues that have reached alarming levels in the last decades. Although growing evidence demonstrates that AD is a significant comorbidity of T2D, and there is a ~1.4-2-fold increase in the risk of developing AD among T2D patients, the involvement of possible common triggers in the pathogenesis of these two diseases remains largely unknown. Of note, recent mechanistic insights suggest that lipotoxicity could represent the missing ring in the pathogenetic mechanisms linking T2D to AD. Indeed, obesity, which represents the main cause of lipotoxicity, has been recognized as a major risk factor for both pathological conditions. Lipotoxicity can lead to inflammation, insulin resistance, oxidative stress, ceramide and amyloid accumulation, endoplasmic reticulum stress, ferroptosis, and autophagy, which are shared biological events in the pathogenesis of T2D and AD. In the current review, we try to provide a critical and comprehensive view of the common molecular pathways activated by lipotoxicity in T2D and AD, attempting to summarize how these mechanisms can drive future research and open the way to new therapeutic perspectives.

Plasma polyunsaturated fatty acid concentrations and sleep apnea risk: A two-sample Mendelian randomization study

Background

Previous observational studies have found that lower levels of circulating polyunsaturated fatty acids (PUFAs) were associated with a higher risk of sleep apnea (SA). However, the causality of the association remains unclear.

Materials and methods

We used the two-sample Mendelian randomization (MR) study to assess the causal association of omega-3 and omega-6 fatty acids with SA. Single-nucleotide polymorphisms (SNPs) predicting the plasma level of PUFAs at the suggestive genome-wide significance level (p < 5 × 10^–6) were selected as instrumental variables (IVs) from the Cohorts for Heart and Aging Research in Genomic Epidemiology (CHARGE) (n = ∼8,000) Consortium. For outcomes, the summary-level statistics of SA were obtained from the latest genome-wide association study (GWAS), which combined five cohorts with a total number of 25,008 SA cases and 172,050 snoring cases (total = 523,366).

Results

We found no association of α-linolenic acid (ALA) [odds ratio (OR) = 1.09 per% changed, 95% confidence interval (CI) 0.67–1.78], eicosapentaenoic acid (EPA) (OR = 0.94, 95% CI 0.88–1.01), docosapentaenoic acid (DPA) (OR = 0.95, 95% CI 0.88–1.02), and docosahexaenoic acid (DHA) (OR = 0.99, 95% CI 0.96–1.02) with the risk of SA using inverse-variance weighted (IVW) method. Moreover, for omega-6 PUFAs, no association between linoleic acid (LA) (OR = 0.98, 95% CI 0.96–1.01), arachidonic acid (AA) (1.00, 95% CI 0.99–1.01), and adrenic acid (AdrA) (0.93, 95% CI 0.71–1.21) with the risk of SA was found. Similarly, no associations of PUFAs with SA were found in single-locus MR analysis.

Conclusion

In the current study, we first found that there is no genetic evidence to support the causal role of omega-3 and omega-6 PUFAs in the risk of SA. From a public health perspective, our findings refute the notion that consumption of foods rich in PUFAs or the use of PUFAs supplementation can reduce the risk of SA.

Metabolomic profiling of the Dietary Approaches to Stop Hypertension diet provides novel insights for the nutritional epidemiology of type 2 diabetes mellitus

Adherence to the Dietary Approaches to Stop Hypertension (DASH) diet is inversely associated with type 2 diabetes mellitus (T2DM) risk. Metabolic changes due to DASH adherence and their potential relationship with incident T2DM have not been described. The objective is to determine metabolite clusters associated with adherence to a DASH-like diet in the Insulin Resistance Atherosclerosis Study cohort and explore if the clusters predicted 5-year incidence of T2DM. The current study included 570 non-diabetic multi-ethnic participants aged 40–69 years. Adherence to a DASH-like diet was determined a priori through an eighty-point scale for absolute intakes of the eight DASH food groups. Quantitative measurements of eighty-seven metabolites (acylcarnitines, amino acids, bile acids, sterols and fatty acids) were obtained at baseline. Metabolite clusters related to DASH adherence were determined through partial least squares (PLS) analysis using R. Multivariable-adjusted logistic regression was used to explore the associations between metabolite clusters and incident T2DM. A group of acylcarnitines and fatty acids loaded strongly on the two components retained under PLS. Among strongly loading metabolites, a select group of acylcarnitines had over 50 % of their individual variance explained by the PLS model. Component 2 was inversely associated with incident T2DM (OR: 0·89; (95 % CI 0·80, 0·99), P-value = 0·043) after adjustment for demographic and metabolic covariates. Component 1 was not associated with T2DM risk (OR: 1·02; (95 % CI 0·88, 1·19), P-value = 0·74). Adherence to a DASH-type diet may contribute to reduced T2DM risk in part through modulations in acylcarnitine and fatty acid physiology.

Crocodile Oil Disrupts Mitochondrial Homeostasis and Exacerbates Diabetic Kidney Injury in Spontaneously Diabetic Torii Rats

Diabetic nephropathy is currently the leading cause of end-stage renal disease (ESRD) in type 2 diabetes. Studies have suggested that supplementation with some fatty acids might reduce the risk and delay the progression to ESRD in patient with chronic kidney disease. Crocodile oil (CO) contains a variety of fatty acids, especially omega-3, -6 and -9, that have been reported to be beneficial to human health. This study examined the impact of long-term CO supplementation on the development of diabetic nephropathy in spontaneously diabetic Torii (SDT) rats. After diabetic verification, SDT rats were assigned to receive vehicle or CO at 500 and 1000 mg/kg BW, respectively, by oral gavage. Age-matched nondiabetic Sprague–Dawley rats were given vehicle or high-dose CO. After 28 weeks of intervention, CO failed to improve hyperglycemia and pancreatic histopathological changes in SDT rats. Unexpectedly, CO dose-dependently exacerbated the impairment of kidney and mitochondrial functions caused by diabetes. CO also disturbed the expressions of proteins involved in mitochondrial biogenesis, dynamics, and mitophagy. However, no significant alterations were observed in nondiabetic rats receiving high-dose CO. The findings reveal that CO has deleterious effects that aggravate diabetic kidney injury via disrupting mitochondrial homeostasis, possibly due to its improper omega-6: omega-3 ratio.

The involvement of FATP1 regulating skeletal muscle fat deposition in stressed broilers was affected by fatty acid substrates

Fatty acid transport protein 1 (FATP1), plays a major role in the transport and uptake of fatty acids into cells. The effect of FATP1 on the regulation of skeletal muscle fat uptake and deposition in stressed broiler chickens was investigated both in vivo and in vitro, and the effect of different fatty acid substrates were also included. Dexamethasone (DEX), a synthetic glucocorticoid (GCs), was employed to induce a hyper glucocorticoid milieu and simulate stress. The in vivo results showed that DEX would increase the mRNA expression of FATP1 and fat deposition in muscle tissues (P < 0.05), the very-low-density lipoprotein (VLDL) and insulin (INS) levels were significantly increased in the plasma by DEX (P < 0.05), and the mRNA levels of the glucocorticoid receptor (GR), adiponectin receptor (ADPNR) and peroxisomal proliferator-activated receptor α (PPARα) in thigh were also up-regulated by DEX (P < 0.05). In vitro experiment, DEX did not affect the myoblast fat deposition and PPARα and FATP1 expressions without the external fatty acid (P > 0.05). Under PA pre-treatment, both myoblast fatty acid uptake and fat deposition were promoted by DEX treatment (P < 0.05), and the effects of DEX on the gene expressions of GR, ADPNR, PPARα and FATP1 were upregulated first and then downregulated as the dose of DEX increases; while under OA pre-treatment, the myoblast fat deposition was not affected by DEX (P > 0.05), the fatty acid uptake was decreased by DEX at 500 nM compared to control (P < 0.05). When GR and PPARα were, respectively inhibited by specific inhibitors RU486 and GW6471, the effects of DEX on fatty acid uptake were reversed for PA pre-treated myoblasts (P < 0.05) but not for OA pre-treated myoblasts (P > 0.05). These results indicate that FATP1 regulation by GCs was affected by fatty acid substrate - saturated fatty acids were favorable for fat uptake and deposition, while unsaturated fatty acids were not. GCs may affect the ADPNR-PPARα-FATP1 pathway by binding to its receptors, thus regulating the uptake of saturated fatty acids into myoblasts.

Types of diet, obesity, and incident type 2 diabetes: Findings from the UK Biobank prospective cohort study

AIM

To investigate the associations between types of diet and incident type 2 diabetes and whether adiposity mediated these associations.

MATERIALS AND METHODS

In total, 203 790 participants from UK Biobank (mean age 55.2 years; 55.8% women) without diabetes at baseline were included in this prospective study. Using the dietary intake data self-reported at baseline, participants were categorized as vegetarians (n = 3237), fish eaters (n = 4405), fish and poultry eaters (n = 2217), meat eaters (n = 178 004) and varied diet (n = 15 927). The association between type of diet and incident type 2 diabetes was investigated using Cox-proportional hazards models with a 2-year landmark analysis. The mediation role of adiposity was tested under a counterfactual framework.

RESULTS

After excluding the first 2 years of follow-up, the median follow-up was 5.4 (IQR: 4.8-6.3) years, during which 5067 (2.5%) participants were diagnosed with type 2 diabetes. After adjusting for lifestyle factors, fish eaters (HR 0.52 [95% CI: 0.39-0.69]) and fish and poultry eaters (HR 0.62 [95% CI: 0.45-0.88]) had a lower risk of incident type 2 diabetes compared with meat eaters. The association for vegetarians was not significant. Varied diet had a higher risk of type 2 diabetes. Obesity partially mediated the association of fish (30.6%), fish and poultry (49.8%) and varied (55.2%) diets.

CONCLUSIONS

Fish eaters, as well as fish and poultry eaters, were at a lower risk of incident type 2 diabetes than meat eaters, partially attributable to lower obesity risk.

Visualising the Emerging Platform of Using Microalgae as a Sustainable Bio-Factory for Healthy Lipid Production through Biocompatible AIE Probes

Nowadays, a particular focus is using microalgae to get high-valued health beneficiary lipids. The precise localisation of the lipid droplets (LDs) and biochemical changes are crucial to portray the lipid production strategy in algae, but it requires an in vivo tool to rapidly visualise LD distribution. As a novel strategy, this study focuses on detecting lipid bioaccumulation in a green microalga, Chlamydomonas reinhardtii using the aggregation-induced emission (AIE) based probe, 2-DPAN (C24H18N2O). As the messenger molecule and stress biomarker, hydrogen peroxide (H2O2) activity was detected in lipid synthesis with the AIE probe, TPE-BO (C38H42B2O4). Distinctive LDs labelled with 2-DPAN have elucidated the lipid inducing conditions, where more health beneficiary α-linolenic acid has been produced. TPE-BO labelled H2O2 have clarified the involvement of H2O2 during lipid biogenesis. The co-staining procedure with traditional green BODIPY dye and red chlorophyll indicates that 2-DPAN is suitable for multicolour LD imaging. Compared with BODIPY, 2-DPAN was an efficient sample preparation technique without the washing procedure. Thus, 2-DPAN could improve traditional fluorescent probes currently used for lipid imaging. In addition, the rapid, wash-free, multicolour AIE-based in vivo probe in the study of LDs with 2-DPAN could advance the research of lipid production in microalgae.

Low Percentage of Vegetable Fat in Red Blood Cells Is Associated with Worse Glucose Metabolism and Incidence of Type 2 Diabetes

The identification of nutritional patterns associated with the development of type 2 diabetes (T2D) might help lead the way to a more efficient and personalized nutritional intervention. Our study is aimed at evaluating the association between fatty acids (FA) in red blood cell (RBC) membranes, as a quantitative biomarker of regular dietary fat intake, and incident type 2 diabetes in a Spanish population. We included 1032 adult Spaniards (57% women, age 49 ± 15 years, 18% prediabetes), without diabetes at study entry, from the Di@bet.es cohort. Incident diabetes was diagnosed at the end of the study follow-up. The FA percentage in RBC was determined at baseline by gas chromatography. Participants were followed on average 7.5 ± 0.6 years. Lower percentages of linoleic acid (LA), α-linolenic (ALA), and eicosapentaenoic acid (EPA), and higher percentages of docosahexaenoic acid (DHA) in RBC membranes were associated, independently of classical risk factors, with worse glucose metabolism at the end of the study follow-up. In addition, higher percentages of ALA and EPA, and moderate percentages of DHA, were associated with lower risk of diabetes. No significant associations were found for LA and diabetes risk. Dietary patterns rich in vegetables are independently associated with lower risk of both deterioration of glucose regulation and incident diabetes, and should be reinforced for the prevention of diabetes.

Variants of the cry 1 gene may influence the effect of fat intake on resting metabolic rate in women with overweight of obesity: a cross-sectional study

BACKGROUND

Previous studies have shown that the minor allele (C allele) for Cry 1 rs2287161, may be associated with increased risk of cardiovascular diseases (CVDs). Low resting metabolic rate (RMR) caused by the diet has been shown to have, potentially, unfavorable effects on obesity. This study sought to investigate the interactions between the Cry 1 Gene and fat intake on RMR in women with overweight of obesity.

METHODS

This comparative cross-sectional study was conducted on 377 Iranian women with overweight of obesity. A food frequency questionnaire (FFQ), with 147 items, was used to assess dietary intake. Individuals were categorized into two groups based on the rs2287161 genotype. Body composition, dietary intake, and RMR were assessed for all participants.

RESULTS

There was a significant difference between genotypes for fasting blood sugar (FBS) (P = 0.04), fat free mass (FFM) (P = 0.0009), RMR per FFM (P = 0.05), RMR per body mass index (BMI) (P = 0.02), and RMR deviation (P = 0.01). Our findings also showed significant interactions between total fat and C allele carrier group on RMR per kg body weight, RMR per body surface area (BSA), RMR per FFM, and RMR deviation (P for interaction < 0.1), in addition to a significant interaction between CC + CG group genotype and polyunsaturated fatty acids (PUFA) intake on RMR per BMI (P for interaction =0.00) and RMR per kg (P for interaction = 0.02) and RMR per BSA (P = 0.07), compared to the GG group, after control for confounder factors.

CONCLUSION

These results highlight that dietary compositions, gene variants, and their interaction, should be acutely considered in lower RMR.

Omega-3 fatty acids reduce cardiometabolic risk in first-episode schizophrenia patients treated with antipsychotics: Findings from the OFFER randomized controlled study

Metabolic syndrome (MetS) increases the risk of premature mortality observed in schizophrenia (SCZ). N-3 polyunsaturated fatty acid (PUFA) deficiency has been reported in different stages of schizophrenia. N-3 PUFA supplementation was found to be beneficial in both chronic SCZ and MetS. No intervention studies based on n-3 PUFA as add-on therapy to antipsychotics have examined the changes in MetS risk in first-episode schizophrenia.

AIM

This randomized placebo-controlled trial assesses the effect of a 26-week intervention composed of either 2.2 g/day of n-3 PUFA or olive oil placebo on the frequency of MetS and the changes in its constituents as a secondary outcome measure.

METHODS

Seventy-one adult inpatients diagnosed with first-episode schizophrenia were randomly assigned to study groups. The active intervention used a 3:2 mixture of eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids. Metabolic syndrome components were monitored throughout the study.

RESULTS

A significant reduction in the frequency of MetS was observed in the EPA + DHA group (p = 0.0408); as well as some specific MetS components: e.g., a decrease in fasting blood glucose (p = 0.045). The beneficial effects of EPA + DHA were even more pronounced in patients treated mainly with olanzapine, e.g. significant reductions of total cholesterol (p = 0.037) and blood glucose levels (p = 0.034). Significant positive correlations were found between the general psychopathology subscale of PANSS (primary outcome) and triglyceride level changes.

CONCLUSION

N-3 PUFA supplementation in early SCZ may constitute a safe and affordable intervention that can reduce the risk of MetS and its lethal complications.

Dietary Management of Type 2 Diabetes in the MENA Region: A Review of the Evidence

The alarmingly rising trend of type 2 diabetes constitutes a major global public health challenge particularly in the Middle Eastern and North African (MENA) region where the prevalence is among the highest in the world with a projection to increase by 96% by 2045. The economic boom in the MENA region over the past decades has brought exceptionally rapid shifts in eating habits characterized by divergence from the traditional Mediterranean diet towards a more westernized unhealthy dietary pattern, thought to be leading to the dramatic rises in obesity and non-communicable diseases. Research efforts have brought a greater understanding of the different pathways through which diet and obesity may affect diabetes clinical outcomes, emphasizing the crucial role of dietary interventions and weight loss in the prevention and management of diabetes. The purpose of this review is to explore the mechanistic pathways linking obesity with diabetes and to summarize the most recent evidence on the association of the intake of different macronutrients and food groups with the risk of type 2 diabetes. We also summarize the most recent evidence on the effectiveness of different macronutrient manipulations in the prevention and management of diabetes while highlighting the possible underlying mechanisms of action and latest evidence-based recommendations. We finally discuss the need to adequately integrate dietetic services in diabetes care specific to the MENA region and conclude with recommendations to improve dietetic care for diabetes in the region.

The contribution of dietary glycemic index and glycemic load to the development of microvascular complications of diabetes

Lifestyle modification, including a healthy diet, is of paramount importance in the management of diabetes mellitus. To this end, diets have been proposed with low glycemic index (an index of carbohydrate food expressing how quickly this nutrient can increase blood glucose) and glycemic load (an index obtained by multiplying the glycemic index by the grams of carbohydrate, then dividing by 100). The aim of this review was to discuss the potential contribution of diets with low glycemic index and glycemic load in diabetic microvascular complications. Currently, their role to the prevention and delay of microvascular complications in diabetes mellitus remains unclear, and further knowledge is desirable.

The effects of low-ratio n-6/n-3 PUFA on biomarkers of inflammation: a systematic review and meta-analysis

OBJECTIVE

The purpose of the systematic review and meta-analysis was to determine if low-ratio n-6/n-3 long-chain polyunsaturated fatty acid (PUFA) supplementation affects serum inflammation markers based on the current studies.

METHODS

PubMed, Embase and The Cochrane library databases were systematically searched to find randomized controlled trials (RCTs) on the effect of low-ratio n-6/n-3 PUFA intervention on inflammation markers up to July 2020. Data were pooled using standardized mean difference (SMD) and 95% confidence intervals (95% CI), with P value ≦ 0.05 as statistical significance.

RESULTS

Thirty-one RCTs were included in the meta-analysis. The analysis indicated that increasing low-ratio n-6/n-3 PUFA supplementation decreased the level of tumor necrosis factor-α (TNF-α) (SMD = -0.270; 95% CI: -0.433, -0.106; P = 0.001) and interleukin 6 (IL-6) (SMD = -0.153; 95% CI: -0.260, -0.045; P = 0.005). There were no significant effects on C-reactive protein (CRP) (SMD = -0.027; 95% CI: -0.189: 0.135; P = 0.741). Subgroup analysis indicated that there was a significant reduction in TNF-α serum concentration in subjects from Asia (SMD: -0.367; 95% CI: -0.579, -0.155; P = 0.001) and in subjects with diseases (SMD: -0.281; 95% CI: -0.436, -0.127; P < 0.001). In the subgroup of the n-6/n-3 ratio ≦5, low-ratio n-6/n-3 PUFA supplementation could decrease the level of TNF-α (SMD: -0.335; 95% CI: -0.552, -0.119; P = 0.002). Serum IL-6 decreased significantly in patients from the Europe subgroup (SMD: -0.451; 95% CI: -0.688, -0.214; P < 0.001), but not in Asia (SMD: -0.034; 95% CI: -0.226, 0.157; P = 0.724), North America (SMD: -0.115; 95% CI: -0.274, 0.044; P = 0.157) and Oceania (SMD: 0.142; 95% CI: -0.557, 0.842; P = 0.690).

CONCLUSION

Low-ratio n-6/n-3 PUFA supplementation could decrease significantly the concentration of serum TNF-α and IL-6, but not decrease CRP concentration.

Novel insights into ferroptosis: Implications for age-related diseases

Rapid increase in aging populations is an urgent problem because older adults are more likely to suffer from disabilities and age-related diseases (ARDs), burdening healthcare systems and society in general. ARDs are characterized by the progressive deterioration of tissues and organs over time, eventually leading to tissue and organ failure. To date, there are no effective interventions to prevent the progression of ARDs. Hence, there is an urgent need for new treatment strategies. Ferroptosis, an iron-dependent cell death, is linked to normal development and homeostasis. Accumulating evidence, however, has highlighted crucial roles for ferroptosis in ARDs, including neurodegenerative and cardiovascular diseases. In this review, we a) summarize initiation, regulatory mechanisms, and molecular signaling pathways involved in ferroptosis, b) discuss the direct and indirect involvement of the activation and/or inhibition of ferroptosis in the pathogenesis of some important diseases, and c) highlight therapeutic targets relevant for ARDs.

Dietary α-Linolenic Acid Counters Cardioprotective Dysfunction in Diabetic Mice: Unconventional PUFA Protection

Whether dietary omega-3 (n-3) polyunsaturated fatty acid (PUFA) confers cardiac benefit in cardiometabolic disorders is unclear. We test whether dietary -linolenic acid (ALA) enhances myocardial resistance to ischemia-reperfusion (I-R) and responses to ischemic preconditioning (IPC) in type 2 diabetes (T2D); and involvement of conventional PUFA-dependent mechanisms (caveolins/cavins, kinase signaling, mitochondrial function, and inflammation). Eight-week male C57Bl/6 mice received streptozotocin (75 mg/kg) and 21 weeks high-fat/high-carbohydrate feeding. Half received ALA over six weeks. Responses to I-R/IPC were assessed in perfused hearts. Localization and expression of caveolins/cavins, protein kinase B (AKT), and glycogen synthase kinase-3 β (GSK3β); mitochondrial function; and inflammatory mediators were assessed. ALA reduced circulating leptin, without affecting body weight, glycemic dysfunction, or cholesterol. While I-R tolerance was unaltered, paradoxical injury with IPC was reversed to cardioprotection with ALA. However, post-ischemic apoptosis (nucleosome content) appeared unchanged. Benefit was not associated with shifts in localization or expression of caveolins/cavins, p-AKT, p-GSK3β, or mitochondrial function. Despite mixed inflammatory mediator changes, tumor necrosis factor-a (TNF-a) was markedly reduced. Data collectively reveal a novel impact of ALA on cardioprotective dysfunction in T2D mice, unrelated to caveolins/cavins, mitochondrial, or stress kinase modulation. Although evidence suggests inflammatory involvement, the basis of this "un-conventional" protection remains to be identified.

Cooking Oil Consumption Is Positively Associated with Risk of Type 2 Diabetes in a Chinese Nationwide Cohort Study

BACKGROUND

Evidence suggests that the relations between intakes of individual fatty acids and risk of type 2 diabetes (T2D) vary. However, associations between intakes of different cooking oils as sources of fatty acids and incident T2D remain largely unknown.

OBJECTIVES

We aimed to evaluate relations between intakes of individual cooking oils and incident T2D in a nationwide Chinese cohort.

METHODS

Overall 15,022 Chinese adults aged ≥20 y from the China Health and Nutrition Survey (CHNS) without self-reported T2D at entry in the 1997, 2000, 2004, 2006, or 2009 rounds were followed up until 2011. Consumption of various cooking oils/fats including lard, peanut oil, soybean oil, canola oil, sesame oil, and refined blended plant oil was assessed using 3-d 24-h records in each survey and the cumulative mean intake was calculated. Multivariable-adjusted Cox proportional hazards regression models were constructed to estimate the HRs of T2D.

RESULTS

A total of 1014 cases were recorded after a median follow-up of 14 y. The intakes of animal and plant cooking oils/fats were both associated with higher T2D risk. Compared with nonconsumers, multivariable-adjusted HRs and 95% CIs for the highest tertiles were 1.31 (1.03, 1.67) for lard, 1.36 (1.10, 1.66) for peanut oil, 1.14 (0.91, 1.43) for soybean oil, 1.11 (0.87, 1.43) for canola oil, 1.02 (0.79, 1.32) for sesame oil, and 1.42 (1.12, 1.82) for refined blended plant oil. Substituting 1 tablespoon/d (8 g · 2000 kcal-1 · d-1) of soybean oil for the sum of lard, peanut oil, refined blended plant oil, and other plant oils was associated with a 3% (HR: 0.97; 95% CI: 0.95, 0.99) lower risk of T2D.

CONCLUSIONS

Intakes of lard, peanut oil, and refined blended plant oil but not soybean oil, canola oil, and sesame oil are associated with higher T2D risk. Reducing the consumption of cooking oils in general may be protective against T2D among the Chinese population.This trial was registered at clinicaltrials.gov as NCT03259321.

Overview of dietary supplements on patients with type 2 diabetes

BACKGROUND AND AIMS

The primary approach for managing type 2 diabetes mellitus (T2DM) involves lifestyle modification and diet therapy along with pharmacologic interventions. Many patients are interested to identify nutritional supplements that may provide benefit in prevention and management of diabetes. However, the efficacy and safety of nutritional supplements such as chromium, n-3 polyunsaturated fatty acids (PUFAs), vitamin D, zinc and magnesium in disease treatment is a worrying and controversial matter. In this narrative review, patients and health care providers are introduced to the effects of mentioned dietary supplements that may help in choosing or not choosing these supplements in treatment of diabetes.

METHODS

This review was carried out using comprehensive and systematic literature reports on the dietary supplements in the management of diabetes. Empirical searches were conducted using Google Scholar, Science Direct and PubMed databases. Searches were also undertaken using keywords, in English, such as "chromium" OR "vitamin D" OR "omega-3 fatty acids" OR "zinc" OR "magnesium" in combination with "type 2 diabetes".

RESULTS

The available evidence is insufficient to create a definite conclusion that nutritional supplements including chromium, n-3 PUFAs, vitamin D, zinc and magnesium might be beneficial for the prevention and treatment of T2DM and therefore, the general recommendation to use these supplements in the management of diabetes cannot be justified. The results of most studies lack uniformity across multiple aspects, including different dose and formation of supplements, duration, and subjects under intervention.

CONCLUSIONS

There is a need for well-designed, high quality, large and long-term studies to strengthen the available evidence and ensure the safety and efficacy of products.

Resolvin E1 derived from eicosapentaenoic acid prevents hyperinsulinemia and hyperglycemia in a host genetic manner

Eicosapentaenoic acid (EPA) has garnered attention after the success of the REDUCE‐IT trial, which contradicted previous conclusions on EPA for cardiovascular disease risk. Here we first investigated EPA's preventative role on hyperglycemia and hyperinsulinemia. EPA ethyl esters prevented obesity‐induced glucose intolerance, hyperinsulinemia, and hyperglycemia in C57BL/6J mice. Supporting NHANES analyses showed that fasting glucose levels of obese adults were inversely related to EPA intake. We next investigated how EPA improved murine hyperinsulinemia and hyperglycemia. EPA overturned the obesity‐driven decrement in the concentration of 18‐hydroxyeicosapentaenoic acid (18‐HEPE) in white adipose tissue and liver. Treatment of obese inbred mice with RvE1, the downstream immunoresolvant metabolite of 18‐HEPE, but not 18‐HEPE itself, reversed hyperinsulinemia and hyperglycemia through the G‐protein coupled receptor ERV1/ChemR23. To translate the findings, we determined if the effects of RvE1 were dependent on host genetics. RvE1's effects on hyperinsulinemia and hyperglycemia were divergent in diversity outbred mice that model human genetic variation. Secondary SNP analyses further confirmed extensive genetic variation in human RvE1/EPA‐metabolizing genes. Collectively, the data suggest EPA prevents hyperinsulinemia and hyperglycemia, in part, through RvE1's activation of ERV1/ChemR23 in a host genetic manner. The studies underscore the need for personalized administration of RvE1 based on genetic/metabolic enzyme profiles.

Vitamin D3 improves lipophagy-associated renal lipid metabolism and tissue damage in diabetic mice

Oxidative stress and abnormal lipid metabolism in diabetes can trigger renal lipotoxicity, extending to diabetic nephropathy. Vitamin D₃ has been known to be involved in lipid metabolism as well as insulin secretion or inflammation. Therefore, we hypothesized that vitamin D₃ supplementation attenuated hyperglycemia-induced renal damage in diabetic mice. Diabetes was induced by a 40% kJ high-fat diet with 30 mg/kg body weight of streptozotocin by intraperitoneal injection twice in male C57BL/6J mice. Among diabetic mice (fasting blood glucose > 140 mg/dL), mice were supplemented with 300 ng/kg body weight of vitamin D₃ dissolved in olive oil for 12 weeks. Normal control and diabetic control mice were orally administrated with olive oil as a vehicle. Normal control mice were fed with an AIN-93G diet during the experiment. Vitamin D₃ supplementation in diabetic mice improved glucose intolerance and kidney function, demonstrated by diminishing glomerular areas. Vitamin D₃ supplementation in diabetic mice significantly reduced triglycerides and low-density lipoprotein cholesterol in plasma as well as triglycerides and total cholesterol in the kidney. Furthermore, vitamin D₃ supplementation attenuated lipid synthesis, oxidative stress, and apoptosis, accompanied by activation of β-oxidation, antioxidant defense enzymes, and autophagy in diabetic mice. In conclusion, vitamin D₃ supplementation ameliorates hyperglycemia-induced renal damage through the regulation of lipid metabolisms, oxidative stress, apoptosis, and autophagy in diabetes. Vitamin D₃ could be a promising nutrient to weaken diabetic nephropathy.

Is There Something Fishy About Fish Oil?

BACKGROUND

Fish is consumed as food worldwide and is considered as a rich source of essential nutrients required for a healthy life. Supplementation with fish oil has been adopted as a solution to prevent or cure many pathophysiological states and diseases by both the professionals and the civil population. The beneficial effects are, however, being questioned, as some controversial results were obtained in clinical and population studies.

METHODS

Critical evaluation of studies regarding known effects of fish oil, both in favour of its consumption and related controversies.

RESULTS

From the literature review, contradictory allegations about the positive action of the fish oil on human health emerged, so that a clear line about its beneficial effect cannot be withdrawn.

CONCLUSION

Scientific results on the application of fish oil should be taken with caution as there is still no standardised approach in testing its effects and there are significantly different baselines in respect to nutritional and other lifestyle habits of different populations.

An overview of phytochemicals and potential health-promoting properties of black walnut

Black walnut contains a diverse mixture of bioactive compounds, including phenolics, phytosterols, unsaturated fatty acids, and tocopherols potentially important to human health.

Changes in Plasma Free Fatty Acids Associated with Type-2 Diabetes

Type 2 diabetes mellitus (T2DM) is associated with increased total plasma free fatty acid (FFA) concentrations and an elevated risk of cardiovascular disease. The exact mechanisms by which the plasma FFA profile of subjects with T2DM changes is unclear, but it is thought that dietary fats and changes to lipid metabolism are likely to contribute. Therefore, establishing the changes in concentrations of specific FFAs in an individual’s plasma is important. Each type of FFA has different effects on physiological processes, including the regulation of lipolysis and lipogenesis in adipose tissue, inflammation, endocrine signalling and the composition and properties of cellular membranes. Alterations in such processes due to altered plasma FFA concentrations/profiles can potentially result in the development of insulin resistance and coagulatory defects. Finally, fibrates and statins, lipid-regulating drugs prescribed to subjects with T2DM, are also thought to exert part of their beneficial effects by impacting on plasma FFA concentrations. Thus, it is also interesting to consider their effects on the concentration of FFAs in plasma. Collectively, we review how FFAs are altered in T2DM and explore the likely downstream physiological and pathological implications of such changes.

Polyunsaturated Fatty Acids and Glycemic Control in Type 2 Diabetes

The impact of dietary fat on the risk of cardiovascular disease (CVD) has been extensively studied in recent decades. Solid evidence indicates that replacing saturated fatty acids (SFAs) with polyunsaturated fatty acids (PUFAs) decreases blood cholesterol levels and prevents CVD and CVD mortality. Studies indicate that fat quality also may affect insulin sensitivity and hence, the risk of type 2 diabetes (T2D). A high intake of SFAs has shown to increase the risk of T2D in prospective studies, while a high intake of PUFAs reduces the risk. Whether PUFAs from marine or vegetable sources affect glycemic regulation differently in T2D remains to be elucidated. The aim of the present review was therefore to summarize research on human randomized, controlled intervention studies investigating the effect of dietary PUFAs on glycemic regulation in T2D. About half of the studies investigating the effect of fish, fish oils, vegetable oils, or nuts found changes related to glycemic control in people with T2D, while the other half found no effects. Even though some of the studies used SFA as controls, the majority of the included studies compared PUFAs of different quality. Considering that both marine and vegetable oils are high in PUFAs and hence both oils may affect glycemic regulation, the lack of effect in several of the included studies may be explained by the use of an inappropriate control group. It is therefore not possible to draw a firm conclusion, and more studies are needed.

Fatty Acid Content and Tumor Growth Changes in Mice After Exposure to Extremely High-Frequency Electromagnetic Radiation and Consumption of N-3 Fatty Acids

The topical problem is to find new, more effective and safe treatments for cancer. The purpose of the present work was to study the combined effects of low-intensity extremely high-frequency electromagnetic radiation (EHF EMR) and consumption of n-3 polyunsaturated fatty acids (PUFAs) on tumor growth and the content of FAs in the thymus and tumor tissue in mice. Fatty acid composition was determined using gas chromatography. Exposure of tumor-bearing mice with solid Ehrlich carcinoma to EHF EMR with effective parameters (42.2 GHz, 0.1 mW/cm², 20 min daily for 5 consecutive days beginning on the first day after the tumor inoculation) led to delaying the tumor growth and restored the content of almost all FAs in thymic tissue to the level of intact animals. Animal intake of the preparation enriched with n-3 PUFAs increased the content of n-3 PUFAs in thymic tissue significantly, but did not affect the tumor growth, even in combination with EHF EMR exposure. Combined action of EHF EMR exposure and n-3 preparation promoted recovery of thymus weight in tumor-bearing animals. The data obtained assume a complex interaction between the immune system and the tumor, and the important role of FAs in the regulation of this interaction.

Association of ADRB2 rs1042713 with Obesity and Obesity-Related Phenotypes and Its Interaction with Dietary Fat in Modulating Glycaemic Indices in Malaysian Adults

Gene-diet interaction studies have reported that individual variations in phenotypic traits may be due to variations in individual diet. Our study aimed to evaluate (i) the association of ADRB2 rs1042713 with obesity and obesity-related metabolic parameters and (ii) the effect of dietary nutrients on these associations in Malaysian adults. ADRB2 genotyping, dietary, physical activity, anthropometric, and biochemical data were collected from 79 obese and 99 nonobese individuals. Logistic regression revealed no association between ADRB2 rs1042713 and obesity (p=0.725). However, the carriers of G allele (AG + GG genotypes) of rs1042713 were associated with increased odds of insulin resistance, 2.83 (CI = 1.04–7.70, adjusted p=0.042), in the dominant model, even after adjusting for potential confounders. Obese individuals carrying the G allele were associated with higher total cholesterol (p=0.011), LDL cholesterol levels (p=0.008), and total cholesterol/HDL cholesterol ratio (p=0.048), compared to the noncarriers (AA), even after adjusting for potential confounders. Irrespective of obesity, the carriers of GG genotype had significantly lower fasting glucose levels with low saturated fatty acid intake (<7.3% of TE/day) (4.92 ± 0.1 mmol/L vs 5.80 ± 0.3 mmol/L, p=0.011) and high intake of polyunsaturated fatty acid:saturated fatty acid ratio (≥0.8/day) (4.83 ± 0.1 mmol/L vs 5.93 ± 0.4 mmol/L, p=0.006). Moreover, the carriers of GG genotype with high polyunsaturated fatty acid intake (≥6% of TE/day) had significantly lower HOMA-IR (1.5 ± 0.3 vs 3.0 ± 0.7, p=0.026) and fasting insulin levels (6.8 ± 1.6 µU/mL vs 11.4 ± 2.1 µU/mL, p=0.036). These effects were not found in the noncarriers (AA). In conclusion, G allele carriers of ADRB2 rs1042713 were associated with increased odds of insulin resistance. Obese individuals carrying G allele were compromised with higher blood lipid levels. Although it is premature to report gene-diet interaction on the regulation of glucose and insulin levels in Malaysians, we suggest that higher quantity of PUFA-rich food sources in regular diet may benefit overweight and obese Malaysian adults metabolically. Large-scale studies are required to replicate and confirm the current findings in the Malaysian population.

Inadequate fat or carbohydrate intake was associated with an increased incidence of type 2 diabetes mellitus in Korean adults: A 12-year community-based prospective cohort study

AIMS

Few studies have focused on the relationship between long-term fat intake and type 2 diabetes mellitus (T2D) risk in Asia where fat intake is relatively lower than the Western countries. We examined association of dietary fat and carbohydrate intake with incidence of T2D among Korean adults.

METHODS

Based on the data from the Korean Genome and Epidemiology Study, a total of 5595 adults aged 40-69 years without diabetes, cardiovascular diseases or any cancer at baseline were included. Dietary intake was measured by the validated semi-quantitative food frequency questionnaire. Cox proportional hazards regression analysis was used to calculate multivariable-adjusted relative risks (RRs) and 95% confidence intervals (CIs).

RESULTS

During a median follow-up of 138-months, 1010 cases of T2D were newly determined. The proportion of participants with fat intake less than 15% of total energy and with carbohydrate intake more than 65% of total energy was 59.0% and 88.9%, respectively. After adjusting for confounders, a very-low-fat intake was associated with an increased risk of T2D (RR of Quartile 1 vs Quartile 4, 1.74; 95% CI, 1.18-2.57; p for trend = 0.0058) in women. A very-high-carbohydrate intake was associated with an increased risk of T2D in men (RR of Quartile 4 vs Quartile 1, 1.54; 95% CI, 1.03-2.30; p for trend = 0.0124) and women (RR of Quartile 4 vs Quartile 1, 1.69; 95% CI, 1.08-2.67; p for trend = 0.0376).

CONCLUSIONS

A very-low-fat or very-high-carbohydrate intake may increase the T2D risk and might be associated with lower intake of various nutrients and unbalanced macronutrient composition.

The effects of silymarin supplementation on metabolic status and oxidative stress in patients with type 2 diabetes mellitus: A systematic review and meta-analysis of clinical trials

OBJECTIVE

The effect of silymarin supplementation on metabolic status and oxidative stress of subjects with type 2 diabetes mellitus (T2DM) has not been conclusively studied. Therefore, the efficacy of silymarin supplementation in these patients was assessed through a meta-analysis.

METHODS

The following databases were searched up to May 15, 2018: PubMed, Scopus, Ovid (Cochrane library), Google scholar and ISI web of science. All randomized clinical trials using silymarin supplements to improve T2DM included in this meta-analysis. Mean Difference (MD) was pooled using a random-effects model.

RESULTS

Eight eligible publications from seven trials were identified for the present meta-analysis. Our results revealed that supplementation with silymarin can decrease fasting blood sugar, hemoglobin A1C, insulin, low-density lipoprotein cholesterol and malondialdehyde and increase high-density lipoprotein cholesterol levels. However, silymarin did not have any significant effects on total cholesterol or triglyceride concentrations.

CONCLUSION

Our data suggest that silymarin supplements have beneficial effects on metabolic status and oxidative stress among patients with T2DM. However, there is currently insufficient evidence to make firm conclusions about the full efficacy of supplementation.

Plasma fatty acids in de novo lipogenesis pathway are associated with diabetogenic indicators among adults: NHANES 2003-2004

Background

Insulin regulates fatty acids (FAs) in the blood; conversely, FAs may mediate insulin sensitivity and are potentially modifiable risk factors of the diabetogenic state.

Objective

The objective of our study was to examine the associations between plasma concentrations of FAs, fasting plasma glucose (FPG), and glycated hemoglobin (HbA1c) among individuals (n = 1433) in the NHANES (2003-2004).

Design

Plasma concentrations of 24 individual FAs were considered individually and in subgroups, per chemical structure. Study participants were categorized in diabetogenic groups: Group 1 (HbA1c ≥6.5% or FPG ≥126 mg/dL), Group 2 (HbA1c 5.7% to <6.5% or FPG 100 to <126 mg/dL), and Group 3 (HbA1c <5.7% and FPG <100 mg/dL). We assessed associations between diabetogenic groups and plasma FAs in multivariate multinomial regressions (with Group 3 as the reference).

Results

Overall, 7.0% of study participants were in Group 1; 33.3% were in Group 2. Plasma concentrations of several individual FAs, including even-chain saturated FAs (SFAs; myristic, palmitic, stearic acids) and monounsaturated FAs (MUFAs; cis-vaccenic, oleic acids), were respectively associated with greater odds of Groups 1 and 2 status, adjusting for covariates. Higher concentrations of SFA and MUFA subgroups (highest compared with lowest quartile) were associated with increased odds of Group 2 status [SFAs adjusted OR (aOR): 1.51 (95% CI: 1.05, 2.18); MUFAs aOR: 1.78 (95% CI: 1.11, 2.85)]. Higher eicosapentaenoic acid plasma concentration was associated with decreased odds of Group 1 status [quartile 4 aOR: 0.41 (95% CI: 0.17, 0.95)].

Conclusions

Higher plasma concentrations of SFAs and MUFAs, primary de novo lipogenesis products, were associated with elevated FPG and HbA1c in a nationally representative study population in the United States. Additional studies are necessary to elucidate potential causal relationships between FAs (from endogenous production and dietary consumption) and diabetogenic indicators, as well as clinical implications for managing diabetes and prediabetes.

Fatty acid quality and quantity of diet and risk of type 2 diabetes in adults: Tehran Lipid and Glucose Study

AIM

Studies suggest that fatty acid intake may be an important determinant of type 2 diabetes mellitus (T2DM). This study aims to prospectively examine the association between fatty acid quantity and quality with risk of T2DM in adults.

METHODS

In this community-based prospective sample, 2139 adults, free of T2DM, aged 20-70y-old were followed for a median of 5.8 y. Diet information was collected with the use of a validated questionnaire at baseline. Cox regression and 95% confidence intervals (CI), adjusted for age, diabetes risk score (DRS), and dietary intakes of energy, fiber and magnesium, were used to evaluate the association of fatty acid intakes with incident T2DM.

RESULTS

During follow-up, we identified 143 incident T2D cases. In multivariable analyses, when extreme quintiles were compared, cholesterol (HR = 0.40; 95% CI: 0.20-0.82; P-trend, 0.02), monounsaturated fatty acids (HR = 0.30; 95% CI: 0.13-0.70; P-trend, 0.02), polyunsaturated fatty acids (HR = 0.45; 95% CI: 0.24-0.93 P-trend = 0.04) and ω-3 fatty acids (HR = 0.55; 95% CI: 0.31-0.88; P-trend = 0.02) were associated with T2DM. The ratio of ω-6 to total ω-3 intake was associated with a higher risk of T2D (HR = 1.65; 95% CI: 1.05-2.86; P-trend, 0.04). We also found positive associations between the ratios of total fat to ω-3 (HR = 1.65; 95% CI: 1.02-2.46; P-trend = 0.05).

CONCLUSIONS

Our findings indicate that diets with high cholesterol, monounsaturated, polyunsaturated and ω-3 fatty acids are associated with a lower risk of T2DM. Also the ratios of ω-6/ω-3 and total fat/ω-3 were positively associated with T2DM.

Orange juice modulates proinflammatory cytokines after high-fat saturated meal consumption

We aimed to evaluate the postprandial secretion of inflammatory markers induced by SFA or MUFA high-fat meal consumption and whether orange juice intake could modulate this induction. This study included 55 healthy women (aged 20 to 40 years): 33 participants received an SFA high-fat meal (≈1000 kcal, 37.6% of energy intake (E) from SFA) and 22 participants received an MUFA high-fat meal (≈1000 kcal, 56.3% E from MUFA). Both interventions were accompanied by 500 ml of orange juice (test) or water (control). The plasma concentrations of inflammatory cytokines (IL-2, IL-4, IL-6, IL-10, IL-17A, IFN-γ, and TNF-α) and CRP were determined before (fasting) and 2, 3 and 5 hours after the test meal intake. The SFA high-fat meal induced a significant increase in AUC values (for TNF-α, IL-12, IL-10, IL-6 and IL-2 adjusted for baseline concentrations) in comparison with MUFA high-fat meal intervention. The results were independent of the drink which accompanied the meal (water or orange juice). Both IL-4 and IL-17A AUC values were significantly increased after an SFA high-fat meal intake, accompanied by water, but not by orange juice. In addition, these values were higher in relation to MUFA high-fat meal interventions. Also, IL-17A significantly increased at 3 h after an SFA high-fat meal intake accompanied by water, but not by orange juice. Overall, our conclusions indicate an anti-inflammatory effect of MUFA compared to SFA high-fat meal intake, while orange juice intake was able to mitigate the subclinical increase of postprandial inflammation, induced by SFA high-fat meal consumption, for a particular biomarker (IL-17A).

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

Background

There are inconsistent data about the role of serum phospholipid fatty acid composition in patients with type 2 diabetes (T2DM) and atherosclerotic cardiovascular disease (ASCVD). The aim of the study was to investigate the relationship between serum phospholipid fatty acid composition, systemic low-grade inflammation, and glycemic control in high-risk T2DM patients.

Methods

Seventy-four patients (26% women, mean age 65.6 ± 6.8 years) with T2DM (median diabetes duration 10 years) and documented ASCVD (74 with coronary artery disease, 26 with peripheral arterial disease) were enrolled in the study. Baseline HbA_1c was estimated using turbidimetric inhibition immunoassay. According to the median value of HbA_1c the patients were grouped into those with HbA_1c < 7.0% (< 53 mmol/mol) (n = 38) and those with HbA_1c ≥ 7.0% (≥ 53 mmol/mol) (n = 36). Serum phospholipid fatty acids were measured with gas chromatography.

Results

Patients with HbA_1c ≥ 7.0%, compared with those with HbA_1c < 7.0% had similar composition of saturated and monounsaturated fatty acids in serum phospholipids, but had higher concentrations of linoleic acid (LA) and higher n-6/n-3 polyunsaturated fatty acid (PUFA) ratio as well as lower levels of eicosapentaenoic acid (EPA), total n-3 PUFAs, and the EPA/arachidonic acid ratio. We found that LA (r = 0.25; p = 0.03) and n-6/n-3 PUFA ratio (r = 0.28; p = 0.02) were positively correlated with HbA_1c. Multivariate logistic regression analysis showed that n-6/n-3 PUFA ratio, hsCRP and T2DM duration were independent predictors of worse glycemic control in patients with T2DM and ASCVD.

Conclusions

This study showed that glycemic control in high-risk T2DM patients with ASCVD was significantly associated with unfavorable serum phospholipid n-6/n-3 PUFA ratio and greater systemic inflammation.