Dietary acid load and its interaction with CETP TaqB1 polymorphisms on lipid profile among patients with Type 2 diabetes mellitus.

OBJECTIVE: Gene-diet interaction plays a key role in the inter-individual differences in lipid abnormalities as a major risk factor for cardiovascular diseases (CVDs). Thus, we explored the interaction between CETP TaqB1 polymorphism with dietary acid load (DAL) on lipid profile among type 2 diabetes mellitus (T2DM). METHOD: This cross-sectional study conducted on 220 Iranian patients with T2DM. Dietary acid load (PRAL and NEAP) was calculated via a validated food-frequency questionnaire (FFQ). The polymerase chain reaction (PCR) used for genotyping Taq1B polymorphism. Biochemical markers were measured by standard protocol. The interaction between CETP Taq1B polymorphism and DAL (PRAL and NEAP) on lipid profile was performed by a generalized linear regression model (GLM). RESULTS: The overall prevalence of rs708272 genotypes was 8.6%, 72.7% and 18.6% for B1B1, B1B2 and B2B2 genotype respectively. This study showed that people with the B1B1 genotype had greater LDL, TC, LDL/HDL, and TG when they consumed diets that scored higher on the NEAP and PRAL indexes than those with the B1B2 and B2B2 genotypes. Besides, carriers of the B1B1 allele who were in the highest tertile of NEAP, had lower HDL (P Interaction < 0.05). CONCLUSIONS: In summary, the lipid profile might be improved in B1B1 homozygotes by less adherence to DAL indexes, however, the findings should be validated in high-quality interventional studies.

Short-chain fatty acid concentrations in the incidence and risk-stratification of colorectal cancer: a systematic review and meta-analysis.

BACKGROUND: The beneficial role of gut microbiota and bacterial metabolites, including short-chain fatty acids (SCFAs), is well recognized, although the available literature around their role in colorectal cancer (CRC) has been inconsistent. METHODS: We performed a systematic review and meta-analysis to examine the associations of fecal SCFA concentrations to the incidence and risk of CRC. Data extraction through Medline, Embase, and Web of Science was carried out from database conception to June 29, 2022. Predefined inclusion/exclusion criteria led to the selection of 17 case-control and six cross-sectional studies for quality assessment and analyses. Studies were categorized for CRC risk or incidence, and RevMan 5.4 was used to perform the meta-analyses. Standardized mean differences (SMD) with 95% confidence intervals (CI) were calculated using a random-effects model. Studies lacking quantitation were included in qualitative analyses. RESULTS: Combined analysis of acetic, propionic, and butyric acid revealed significantly lower concentrations of these SCFAs in individuals with a high-risk of CRC (SMD = 2.02, 95% CI 0.31 to 3.74, P = 0.02). Additionally, CRC incidence was higher in individuals with lower levels of SCFAs (SMD = 0.45, 95% CI 0.19 to 0.72, P = 0.0009), compared to healthy individuals. Qualitative analyses identified 70.4% of studies reporting significantly lower concentrations of fecal acetic, propionic, butyric acid, or total SCFAs in those at higher risk of CRC, while 66.7% reported significantly lower concentrations of fecal acetic and butyric acid in CRC patients compared to healthy controls. CONCLUSIONS: Overall, lower fecal concentrations of the three major SCFAs are associated with higher risk of CRC and incidence of CRC.

Interactions between Caveolin-1 (rs3807992) polymorphism and major dietary patterns on cardio-metabolic risk factors among obese and overweight women.

BACKGROUND: Caveolin-1 (CAV-1) is a cholesterol-dependent essential component located in caveolae. Several studies have been CAV-1 related to cardio-metabolic parameters in animal models, however, there are few studies in humans. Importantly, there is no study has investigated the interaction between CAV-1 rs3807992 gene and dietary patterns (DPs) on cardio-metabolic risk factors. METHODS: The current cross-sectional study was conducted on 404 overweight and obese women. Dietary intake was obtained from FFQ with 147 items. The CAV-1 genotype was measured by the PCR-RFLP method. The anthropometric measurements, serum lipid profile, and inflammatory markers were measured by standard protocols. RESULTS: There was a significant interaction between CAV-1 rs3807992 and healthy DP on high-density cholesterol (HDL) (P-interaction = 0.03), TC/HDL (P-interaction = 0.03) and high sensitivity C-reactive protein (hs-CRP) (P-interaction = 0.04); in A-allele carriers, higher following a healthy DP was related to a higher level of HDL and lower TC/HDL and hs-CRP. As well as, the significant interactions were observed between CAV-1 rs3807992 and unhealthy DP in relation to triglyceride (TG) (P-interaction = 0.001), aspartate aminotransferase (AST) (P-interaction = 0.01) and monocyte chemoattractant protein-1(MCP-1) (P-interaction = 0.01); A-allele carriers were more following the unhealthy DP had lower levels of TG, AST and MCP-1. CONCLUSIONS: Our study revealed a significant gene-diet interaction between rs3807992 SNPs and DPs in relation to cardio-metabolic risk factors; A-allele carriers might be more sensitive to dietary composition compared to GG homozygotes. Following a healthy DP in A-allele-carriers may be improved their genetic association with cardio-metabolic risk factors.

Vitamin D downregulates key genes of diabetes complications in cardiomyocyte.

OBJECTIVE: Vitamin D deficiency has been reported to be associated with the incidence of type 1 and type 2 diabetes and worsening of diabetes complications. This study was designed to investigate the effect of vitamin D treatment on the expression of five key genes involved in the development of diabetic cardiomyopathy. METHODS: Twenty-four male Sprague-Dawley rats were randomly divided into three groups. The first group served as control and the other two groups received an intraperitoneal injection of 45 mg/kg streptozotocin (STZ) to develop diabetes. Then groups were treated for 4 weeks either with placebo or vitamin D (two injections of 20,000 IU/kg). Serum levels of glucose, insulin, HbA1c, and advanced glycation end products (AGEs), as well as the gene expression of AGE cellular receptor (RAGE), glyoxalase, aldose reductase, O-GlcNAc transferase (OGT), and glutamine-fructose-6-phosphate aminotransferase (GFAT) and nuclear factor-kB (NF-kB) activity of nuclear extracts were assessed at the end of experiment. RESULTS: Increment in serum cholecalciferol could improve hyperglycaemia and hypoinsulinemia in diabetic rats. In addition, a significant reduction was observed in RAGE, OGT, and GFAT gene expression and NF-kB activity in cardiac myocytes. CONCLUSIONS: Vitamin D might contribute in reducing diabetic cardiomyopathy not only by improving blood glucose and insulin levels but also via downregulating AGE and hexosamine pathways and decreasing NF-kB activity in heart tissue.

The interaction between apolipoprotein B insertion/deletion polymorphism and macronutrient intake on lipid profile and serum leptin and ghrelin levels in type 2 diabetes mellitus patients.

PURPOSE: We aimed to study whether macronutrient intake could modify the association between ApoB Ins/Del and lipid profile, and serum leptin and ghrelin in type 2 diabetes mellitus (T2DM) patients. METHODS: In this study, 700 T2DM patients were recruited. Anthropometric, biochemical and molecular data were collected, and Diet was assessed using a food frequency questionnaire. The interactions were tested using ANCOVA. RESULTS: Del-allele carriers with high-MUFA and carbohydrate (≥ 12 and ≥ 54% of energy, respectively) had significantly higher TG (P = 0.04) and LDL-C (P = 0.02) compared to Ins/Ins homozygotes, and these were not significant in subjects with low-MUFA and -carbohydrate (< 12 and < 54%, respectively). A significant interaction was observed between ApoB Ins/Del and diet on TG in both unadjusted (P = 0.03) and adjusted models (model 2 and 3, P = 0.04 and P = 0.04, respectively), and on LDL-C only in adjusted models (model 2 and 3, P = 0.03 and P = 0.029, respectively). Besides, Del-allele carriers with protein, SFA, MUFA and n-3PUFA of ≥ 14, 9, 12 and 0.6%, respectively, had a significant increase in their serum leptin than Ins/Ins homozygotes (P < 0.05). However, these associations were not significant between the two genetic groups in subjects with low intakes of protein, SFA, MUFA and n-3PUFA. Moreover, Del-allele carriers with low carbohydrate (< 54%) had significantly higher leptin and ghrelin than Ins/Ins homozygotes (P < 0.05), however, in high-carbohydrate group, leptin and ghrelin were not significantly lower. CONCLUSIONS: These findings indicate that the interaction between ApoB Ins/Del and dietary intake of MUFA, SFA, n-3PUFA, carbohydrate and protein could modulate the serum levels of TG, LDL-C, leptin and ghrelin in T2DM patients.

The effect of 1, 25(OH)2 D3 (calcitriol) alone and in combination with all-trans retinoic acid on ROR-γt, IL-17, TGF-ß, and FOXP3 gene expression in experimental autoimmune encephalomyelitis.

OBJECTIVES: It has been shown that calcitriol and all-trans retinoic acid (ATRA) have modulatory effects on the immune system. The present study investigates the synergistic effects of combination treatment of calcitriol and ATRA in experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis (MS). METHODS: The mice were allocated to four preventive groups, each consisting of eight animals, ATRA (250 µg/mouse), calcitriol (100 ng/mouse), combination of ATRA and calcitriol (125  µg/mouse and 50 ng/mouse) and vehicle groups. EAE was induced by MOG35-55 peptide in female C57BL/6 mice. Treatments were initiated at day 1 before immunization and continued every other day throughout the study until the day 21 post-immunization. Splenocytes were isolated from EAE-induced mice and the expression of retinoic acid receptor-related orphan receptor gamma t (ROR-γt), Interleukin-17 (IL-17), transforming growth factor beta (TGF-ß), and forkhead box P3 (FOXP3) genes was measured using real-time polymerase chain reaction. RESULTS: The expression of FOXP3 and TGF-ß genes in the splenocytes of combination-treated and calcitriol alone-treated mice was significantly increased compared to vehicle group (P < 0.05). The expression of ROR-γt and IL-17 genes in the splenocytes of ATRA, calcitriol and combination- treated mice was significantly reduced compared to those of vehicle- treated mice (P < 0.05). The relative expression level of ROR-γt was significantly (P < 0.05) lower in the combination group than in the mice treated by ATRA or calcitriol alone. DISCUSSION: This study demonstrated that treatment with combination of calcitriol and ATRA can be considered as a new strategy for MS prevention and treatment.

The Effects of Nano-curcumin Supplementation on Leptin and Adiponectin in Migraine Patients: A Double-blind Clinical Trial Study from Gene Expression to Clinical Symptoms.

BACKGROUND: Migraine is a disabling neurogenic disorder characterized by recurrent headache attacks. Adipokines act as inflammatory and pain mediators that contribute to migraine pathogenesis. Leptin and adiponectin levels change in migraine patients and are associated with headache attacks. Curcumin can exert modulatory and analgesic effects on adipokines through several mechanisms, from gene expression to suppressing pain. The aim of the present study was to evaluate the effects of nano-curcumin supplementation on leptin and adiponectin gene expression, their serum levels and migraine symptoms in patients with migraine. METHODS: Forty-four episodic migraine patients enrolled in this trial were divided into two groups as nano-curcumin (80 mg/day) and placebo group, over a two-month period. At the beginning and the end of the study, the mRNA expression of leptin and adiponectin from isolated PBMCs and their serum levels were measured using real-time PCR and ELISA method, respectively. The headache frequencies, severity and duration of pain were also recorded. RESULTS: The results of the present research showed that nano-curcumin can up-regulate adiponectin mRNA and increase its serum level significantly (P < 0.05). In the case of leptin, a reduction in gene expression and concentration was found in the nano-curcumin group but it was not statistically significant (P > 0.05). Nano-curcumin also significantly reduced the frequency, severity and duration of headaches (P < 0.05). CONCLUSION: These findings indicate that nano-curcumin supplement can be considered as a promising approach to migraine management and clinical symptoms improvement.

Dietary pattern in autism increases the need for probiotic supplementation: A comprehensive narrative and systematic review on oxidative stress hypothesis.

Autism spectrum disorders (ASDs) are associated with specific dietary habits, including limited food selection and gastrointestinal problems, resulting in an altered gut microbiota. Autistic patients have an elevated abundance of certain gut bacteria associated with increased oxidative stress in the gastrointestinal tract. Probiotic supplementation has been shown to decrease oxidative stress in a simulated gut model, but the antioxidant effects of probiotics on the oxidative stress of the gut in autistic patients have not been directly studied. However, it is speculated that probiotic supplementation may help decrease oxidative stress in the gastrointestinal tract of autistic patients due to their specific dietary habits altering the microbiota. PubMed, Scopus and Web of Science databases and Google Scholar were searched up to May 2023. This systematic-narrative review aims to present the latest evidence regarding the changes in eating habits of autistic children which may further increase the gut microbiota induced oxidative stress. Additionally, this review will assess the available literature on the effects of probiotic supplementation on oxidative stress parameters.

Effects of vitamin D supplementation on liver fibrogenic factors in non-alcoholic fatty liver patients with steatohepatitis: study protocol for a randomized clinical trial.

BACKGROUND: It has been suggested that vitamin D and its receptors involve in suppressing fibrogenic signaling in non-alcoholic fatty liver disease (NAFLD). However, the effect of vitamin D supplementation on fibrogenic factors has not been investigated in NAFLD individuals with steatohepatitis. This study was designed to examine the effects on vitamin D supplementation on serum levels of vitamin D receptor (VDR), fibrogenic factors, and fibrogenic microRNAs (MiR) in NAFLD patients. METHODS: Forty-six NAFLD patients will be recruited in this study. After block matching for sex and BMI, they will be randomly assigned to receive 4000 IU/day vitamin D or placebo for 12 weeks. Weight, height, and waist circumference will be measured. Determination of serum fibrogenic MiRs, laminin, collagen type IV, hyaluronic acid, vitamin D, VDR, calcium, blood glucose, serum insulin, lipid profile, liver markers (ALT, AST, total, direct, and indirect bilirubin) will be done at study baseline and at the end of the trial. Insulin resistance and insulin sensitivity will be determined using the HOMA-IR and QUICKI equation. DISCUSSION: This is the first randomized controlled trial that will determine the effect of vitamin D supplementation on serum levels of VDR, fibrogenic factors, and fibrogenic MiRs in NAFLD patients. The results of this trial will provide clinical evidence on the effectiveness of vitamin D supplementation in controlling liver fibrosis in NAFLD patients. TRIAL REGISTRATION: Iranian Registry of Clinical Trials, IRCT201405251485N13 . Registered on 14 March 2017.

Effects of vitamin D supplementation on advanced glycation end products signaling pathway in T2DM patients: a randomized, placebo-controlled, double blind clinical trial.

BACKGROUND: Several researches have recommended vitamin D possible health benefits on diabetic complications development, but a few number of studies have been accomplished on the molecular and cellular mechanisms. Certain cellular pathways modification and also some transcription factors activation may protect cells from hyperglycemia condition induced damages. This study purpose was to determine the vitamin D supplementation effect on some key factors [advanced glycation end products (AGEs) signaling pathway] that were involved in the diabetic complications occurrence and progression for type-2 diabetes participants. METHODOLOGY: 48 type-2 diabetic patients (T2DM) randomly divided into two groups (n = 24 per group), receiving: 100-µg vitamin D or placebo for 3 months. At this study beginning and the end, the receptor expression for advanced glycation end products (RAGE) and glyoxalase I (GLO1) enzyme from peripheral blood mononuclear cells (PBMCs) and AGEs and tumor necrosis factor-α (TNF-α) serum levels were measured by the use of real-time PCR and ELISA methods, respectively. RESULTS: This study results demonstrated that vitamin D supplementation could down-regulate RAGE mRNA [fold change = 0.72 in vitamin D vs. 0.95 in placebo) P = 0.001)]. In addition, no significant changes were observed for GLO1 enzyme expression (P = 0.06). This study results also indicated that vitamin D serum level significantly increased in vitamin D group (P < 0.001). Moreover, AGES and TNF-α serum levels significantly reduced in vitamin D group, but they were remained unchanged in the placebo group. CONCLUSION: In conclusion, vascular complications are more frequent in diabetic patients, and vitamin D treatment may prevent or delay the complications onset in these patients by AGEs serum level and RAGE gene expression reducing.Trial registration NCT03008057. Registered December 2016.

Effects of vitamin D supplementation on circulatory YKL-40 and MCP-1 biomarkers associated with vascular diabetic complications: A randomized, placebo-controlled, double-blind clinical trial.

AIM: Diabetic patients predispose to vascular diseases such as nephropathy, and retinopathy. Poor adherence to medical treatment and dietary recommendations in uncontrolled diabetes leads to vascular damages. Vitamin D has been extensively studied and found to be protective against diabetes mellitus. YKL-40 and Monocyte chemoattractant protein-1 (MCP-1) are considered to exert crucial role in diabetes and its complications. Therefore, this study was designed to investigate effects of vitamin D supplementation on serum levels of YKL-40 and MCP-1 involved in the development of diabetic complications. METHODS: For 12 weeks, 48 type 2 diabetic patients enrolled in the trial and randomly were divided into two groups (n = 24 per group), receiving one of the following: 100 µg (4000 IU) vitamin D or placebo. Before and after intervention, serumYKL-40, MCP-1, insulin, IL-6, TNF-α, 25- (OH) vitamin D and HbA1c were measured. RESULTS: Our results revealed that serum levels of 25 (OH) vitamin D significantly increased in vitamin D group (p < 0.001). Vitamin D supplementation also significantly reduced serum YKL-40 levels (-22.7 vs. -2.4 ng/ml; (p-value = 0.003)). There was a significant decline in MCP-1 concentration in intervention group at the end of the study (-45.7 vs. -0.9 pg/ml; (p = 0.001)). Furthermore, there was a significant decrease in IL-6, fasting insulin and HOMA-IR in intervention group after 3 months supplementation. CONCLUSIONS: Daily vitamin D supplementation effectively reduced circulatory YKL-40 and MCP-1 levels in patients with type-2 diabetes and vitamin D deficiency. Vitamin D might contribute in reducing diabetic complications via modulating YKL-40 and MCP-1 signaling pathways.

The Effect of Vitamin D on Cellular Pathways of Diabetic Nephropathy.

BACKGROUND: Diabetic nephropathy is one of the most important microvascular complications and a major cause of morbidity and mortality in diabetic patients. This study was designed to investigate the effect of vitamin D on the expression of three key genes involved in the development of diabetic nephropathy. METHODS: Twenty-four male Sprague-Dawley rats were randomly divided into three groups. The first group served as control and the other two groups received intraperitoneal injections of 45 mg/kg STZ to develop diabetes. The groups were treated for four weeks either with placebo or two vitamin D injections of 20,000 IU/kg. Serum glucose, insulin, and HbA1c levels, and AGE cellular receptor (RAGE), aldose reductase (AR) and glutamine: fructose-6-phosphate aminotransferase (GFAT) gene expression were assessed in kidney tissue at the end of the experiment. RESULTS: Vitamin D treatment resulted in a significant increase in insulin concentration, which could improve hyperglycaemia in diabetic rats. Serum HbA1c decreased slightly but insignificantly following the vitamin D injections. In addition, expression of GFAT, a key regulatory enzyme in the hexosamine pathway, was significantly reduced following vitamin D administration. CONCLUSION: Vitamin D may reduce diabetic nephropathy not only by improving blood glucose and insulin levels, but also by modulating hexosamine pathways in kidney.

Vitamin D suppresses cellular pathways of diabetes complication in liver.

OBJECTIVES: The aim of this study was to investigate the effect of vitamin D on glucose metabolism, as well as the expression of five key genes involved in the development of diabetes complications in liver tissue of diabetic rats. MATERIALS AND METHODS: Twenty-four male Sprague-Dawley rats were randomly divided into three groups (8 rats in each group). The first group served as control and the other two groups received an intraperitoneal injection of 45 mg/kg streptozotocin to develop diabetes. Groups were treated for four weeks either with placebo or vitamin D (two injections of 20000 IU/kg). Thereafter, serum levels of glucose, insulin and HbA1c were assessed. Liver tissue was examined for the level of advanced glycation end products (AGEs) and the gene expression of AGE cellular receptor (AGER), glyoxalase-1 (GLO-1), aldose reductase (AR), O-linked N-acetylglucosamine transferase (OGT) and glutamine/ fructose-6-phosphate aminotransferase (GFAT). RESULTS: Vitamin D injection resulted in a significant increase in plasma level of 25-hydroxycholecalciferol, which could improve hyperglycemia about 11% compared to placebo-receiving diabetic rats (P=0.005). Insulin level increased as a result of vitamin D treatment compared to control (3.31±0.65 vs. 2.15±0.79; P= 0.01). Serum HbA1c and liver AGE concentrations had a slight but insignificant reduction following vitamin D intake. Moreover, a significant decline was observed in gene expression of AGER and OGT in liver tissue (P=0.04 and P<0.001 respectively). CONCLUSION: Vitamin D might contribute in ameliorating diabetes complications not only by improving blood glucose and insulin levels, but also by suppressing AGER and OGT gene expression in the liver.

Differences in the interaction between CETP Taq1B polymorphism and dietary fat intake on lipid profile of normolipedemic and dyslipidemic patients with type 2 diabetes mellitus.

BACKGROUND & AIM: Dyslipidemia is one of the major complications in patients with type 2 diabetes mellitus (T2DM). Dietary fat intake and genetic factors including CETP Taq1B polymorphism could also affect lipid profile concentrations, in particular HDL-c. We decided to study the frequency of this polymorphism and its interaction with dietary fat intake on HDL-c concentration among Iranian T2DM patients with and without dyslipidemia. METHODS: In this comparative study, serum samples were collected from 55 patients with dyslipidemia and 129 patients without dyslipidemia. Validated semi-quantitative FFQ was used for food consumption data. CETP Taq1B polymorphism was studied by polymerase chain reaction-restriction length polymorphism (PCR-RFLP). We used χ2 and two-way ANOVA tests for statistical analysis. RESULTS: The frequency of B1B1 genotype was higher in patients with dyslipidemia (p = 0.01). There was no significant relationship between CETP Taq1B polymorphism and lipid profile concentrations. In patients without dyslipidemia, the interaction between the polymorphism and total fat intake on HDL-c concentration as well as TG/HDL ratio was significant (p = 0.02 and p = 0.009 respectively). This was more evident in B1B1 genotype. Moreover, HDL-c concentration was significantly higher in B2B2 genotype with low total fat intake. CONCLUSION: Higher total fat intake may affect the relationship between CETP Taq1B polymorphism and HDL-c concentration in patients with normolipidemic T2DM.

Vitamin D3 Induces Gene Expression of Ox-LDL Scavenger Receptors in Streptozotocin-Induced Diabetic Rat Aortas: New Insight into the Role of Vitamin D in Diabetic Atherosclerosis.

BACKGROUND: Several lines of evidence suggest that oxidized LDL (Ox-LDL) scavenger receptors play a crucial role in the genesis and progression of diabetic atherosclerosis. This study aimed to elucidate the effect of vitamin D3 on gene expression of lectin-like oxidized LDL receptor-1 (LOX-1), scavenger receptor-A (SR-A), Cluster of Differentiation 36 (CD36), and Cluster of Differentiation 68 (CD68) as the main Ox-LDL receptors in streptozotocin (STZ)-induced diabetic rat aortas. METHODS: Eighteen Sprague-Dawley rats were randomly divided into three groups of six rats each. Two rats died during the study so five rats from each group were analyzed at the study's end. Diabetes was induced in overnight starved rats in two of the groups by intraperitoneal injections of 60 mg/kg of STZ. The vitamin D3/diabetic group then received weekly intraperitoneal injections of 5000 IU/kg of vitamin D3 dissolved in cottonseed oil for four weeks, diabetic controls received cottonseed oil, and healthy controls received sterile saline weekly for the same period. At the end of the four-week study period the animals were killed and the aortas were collected to examine the mRNA expression using real-time polymerase chain reaction (RT-PCR). RESULTS: SR-A and CD36 mRNA expression were significantly greater in the vitamin D3/diabetic rats than in both the diabetic control and healthy control rats. CD68 and LOX-1 expression were greater in the vitamin D3/diabetic rats than in the diabetic control and healthy control rats, respectively. CONCLUSION: Vitamin D3 may increase the risk of diabetic atherosclerosis by inducing scavenger receptors expression.

DHA-enriched fish oil upregulates cyclin-dependent kinase inhibitor 2A (P16INK) expression and downregulates telomerase activity without modulating effects of PPARγ Pro12Ala polymorphism in type 2 diabetic patients: A randomized, double-blind, placebo-controlled clinical trial.

OBJECTIVE: The present study investigated the effects of docosahexaenoic acid (DHA)-enriched fish oil supplement on telomerase activity, mRNA expression of P16INK, IL-6, and TNF-α considering Pro12Ala polymorphism in the PPARγ gene. METHODS/DESIGN: In this double-blind randomized controlled trial, 72 PPARγ Pro12Ala polymorphism genotyped type 2 diabetic patients aged 30-70 years were randomly assigned to receive 2.4 gr of DHA-enriched fish oil or a placebo for 8 weeks. Genotyping of the Pro12Ala polymorphism in the PPARγ gene was assessed using polymerase chain reaction-restriction length polymorphism (PCR-RFLP), telomerase activity in the peripheral blood mononuclear cell (PBMC) was measured using PCR-ELISA based on the telomeric repeat amplification protocol (TRAP), and changes in the mRNA expression of P16, IL-6, and TNF-α were measured using real-time quantitative reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: In the DHA group, telomerase activity was decreased (p = 0.001) during the intervention. In addition, between-group comparisons showed significant differences in the changes in telomerase activity (p = 0.003) and P16 mRNA expression (p = 0.028) and non-significant differences in TNF-α and IL-6 mRNA expression. The gene*DHA interaction could not affect changes in P16, IL-6, or TNF-α mRNA expression or in telomerase activity in PBMC. DISCUSSION: Short-time DHA-enriched fish oil supplementation caused increased levels of P16 expression and a decline in telomerase activity compared with the control group without modulating the effects of Pro12Ala polymorphism on the PPARγ gene. Because of the positive correlation between P16 activity and cellular senescence, the possibility of senescence stimulation by DHA is proposed.

Dietary ω-3 polyunsaturated fatty acid intake modulates impact of Insertion/Deletion polymorphism of ApoB gene on obesity risk in type 2 diabetic patients.

OBJECTIVES: The goal of the study described here was to determine whether dietary ω-3 polyunsaturated fatty acid (PUFA) intake modulates the association between ApoB Ins/Del polymorphism and obesity in type 2 diabetic patients. METHODS: In this cross-sectional study, 700 patients with type 2 diabetes were recruited in Tehran. Weight and waist circumference (WC) were measured, and body mass index (BMI) was calculated. Dietary intake was assessed using a validated semiquantitative food frequency questionnaire. ApoB genotyping was performed with 8% polyacrylamide gel electrophoresis. RESULTS: We observed a significant interaction between Ins/Del genotype and dietary ω-3 PUFA intake with respect to BMI, WC, and obesity risk in both unadjusted (P = 0.007, P = 0.001, and P = 0.021, respectively) and adjusted (P = 0.007, P = 0.04, and P = 0.002, respectively) samples. Thus, the carriers of the Del allele were only associated with lower BMI (P = 0.01) and WC (P = 0.002) among individuals with high ω-3 PUFA intake (≥0.6% of energy), but not in those with low ω-3 PUFA intake (<0.6%). Also, when dietary ω-3 PUFA was <0.6%, general obesity risk in carriers of the Del allele was about 1.6 times higher than that of Ins/Ins homozygotes (odds ratio = 1.59, 95% confidence interval: 1.05-2.52, P = 0.039). But with high ω-3 PUFA intake (≥0.6%), the risk was 0.46 times lower (odds ratio = 0.46, 95% confidence interval: 0.25-0.79, P = 0.003). Moreover, a similar interaction was observed in central obesity only in men after adjustment for confounder variables (P = 0.041). CONCLUSIONS: These findings support the hypothesis that a diet high in ω-3 PUFA (≥0.6%) can decrease the obesity risk in carriers of the Del allele of ApoB gene.

Effects of DHA Supplementation on Vascular Function, Telomerase Activity in PBMC, Expression of Inflammatory Cytokines, and PPARγ-LXRα-ABCA1 Pathway in Patients With Type 2 Diabetes Mellitus: Study Protocol for Randomized Controlled Clinical Trial.

Docosahexaenoic acid (DHA), as an omega-3 fatty acid, in a natural ligand of peroxisome proliferator-activated receptors (PPARs). Regarding the combinative effects of Nutrigenomics and Nutrigenetics and due to the lack of in vivo studies conducted using natural ligands of PPARs, we aimed to evaluate the effects of DHA supplementation on vascular function, telomerase activity, and PPARγ-LXRα-ABCA1 pathway, in patients with type 2 diabetes mellitus (T2DM), based on the Pro12Ala polymorphism in PPARγ encoding gene. 72 T2DM patients (36 dominant and 36 recessive allele carriers), aged 30-70, with body mass index of 18.5 to 35 kg/m2, will be participated in this double blind randomized controlled trial. In each group, stratification will be performed based on sex and age and participants will be randomly assigned to receive 2.4 g/day DHA or placebo (paraffin) for 8 weeks. PPARγ genotyping will be carried out using PCR-RFLP method; Telomerase activity will be estimated by PCR-ELISA TRAP assay; mRNA expression levels of target genes will be assessed using real time PCR. Serum levels of ADMA, sCD163 and adiponectin, will be measured using ELISA commercial kits. The present study is designed in order to help T2DM patients to modify their health conditions based on their genetic backgrounds, and to recommend the proper food ingredients as the natural agonists for PPARs in order to prevent and treat metabolic abnormalities of the disease.

APOA2 -256T>C polymorphism interacts with saturated fatty acids intake to affect anthropometric and hormonal variables in type 2 diabetic patients.

Recent studies have established the interaction between APOA2 -256T>C polymorphism and dietary saturated fatty acids intake in relation to obesity on healthy individuals. In the current study, we investigate the effects of this interaction on anthropometric variables and serum levels of leptin and ghrelin in patients with type 2 diabetes. In this cross-sectional study, 737 patients with type 2 diabetes mellitus (290 males and 447 females) were recruited from diabetes clinics in Tehran. The usual dietary intake of all participants during the last year was obtained by validated semiquantitative food frequency questionnaire. APOA2 genotyping was performed by real-time PCR on genomic DNA. No significant relation was obtained by univariate analysis between anthropometric variables and APOA2 genotypes. However, after adjusting for age, gender, physical activity and total energy intake, we identified a significant interaction between APOA2-saturated fatty acids intake and body mass index (BMI). After adjusting for potential confounders, serum levels of ghrelin in CC genotype patients were significantly higher than T allele carriers (p = 0.03), whereas the case with leptin did not reveal a significant difference. The result of this study confirmed the interaction between APOA2 -256T>C polymorphism and SFAs intake with BMI in type 2 diabetic patients. In fact, homozygous patients for the C allele with high saturated fatty acids intake had higher BMI. The APOA2 -256T>C polymorphism was associated with elevated levels of serum ghrelin.