Association between dietary antioxidants intake and the risk of type 2 diabetes mellitus in a prospective cohort study: Tehran Lipid and Glucose Study.

The present prospective cohort study aimed to determine whether dietary antioxidants were associated with incident type 2 diabetes mellitus (T2DM). Another objective was to find out whether such associations could be modified by the BMI status. A total of 2188 Tehranian adults aged 21-84 years, free of T2DM with the validated FFQ, was entered in the study. Multivariable Cox proportional hazards models adjusting for confounders were used to assess the association between dietary antioxidants and incident T2DM in total population, as well as in subjects with various BMI statuses. During 8·9 (8·1-9·6) years of follow-up, dietary vitamin E significantly decreased the incident T2DM, after adjustment for confounders. However, other dietary antioxidants were not shown to be significantly associated with incident T2DM. The interaction between dietary vitamin E, Mg and BMI status was found to influence the risk of T2DM (Pfor interaction < 0·05). After stratification of subjects based on BMI status, it was found that vitamin E and Mg decreased the risk of T2DM only among normal-weight individual. Also, an inverse association was found among dietary vitamin C, dietary Zn and the risk of T2DM in individuals with normal weight but not in overweight and obese individuals; however, the interaction test tended to be significant for these dietary variables. Dietary antioxidants including vitamin E, vitamin C, Zn and Mg when accompanied by healthy weight, may bring benefits to the prevention of T2DM.

The association between ultra-processed food consumption and health-related quality of life differs across lifestyle and socioeconomic strata.

BACKGROUND: In this prospective study, we aimed to examine the association between ultra-processed foods and health-related quality of life (HRQoL) and to evaluate the effect of lifestyle and socioeconomic factors on this association. METHODS: This study included 1766 adults (aged 18 to 78, 54.3% women), who took part in the Tehran Lipid and Glucose study. The Short-Form 12-Item Health Survey version 2 was used to determine HRQoL, which includes the physical component summary (PCS) and mental component summary (MCS) scores. Ultra-processed food consumption was assessed using a validated semi-quantitative food frequency questionnaire. Lifestyle (physical activity and smoking status) and socioeconomic factors (education level and employment status) were also determined. General linear models (GLM) were applied to estimate the mean (95% confidence interval) for MCS and PCS scores across the ultra-processed foods tertiles. Additionally, the effect of lifestyle and socioeconomic factors on the relationship between ultra-processed foods and HRQoL was examined using GLM. RESULTS: The median consumption of ultra-processed foods was 11.9% (IQR: 8.2 to 16.8) of total energy intake. There was a significant inverse association between ultra-processed foods consumption and PCS, but not MCS, after adjustment for confounding factors. Significant interactions were observed between ultra-processed food consumption, sex, and occupation on PCS score (all P values < 0.001). The interaction test tended to be significant for smoking status, education levels, and physical activity levels. As ultra-processed food consumption increased, the PCS score significantly decreased in women (P = 0.043), low physical active subjects (P = 0.014), smokers (P = 0.015), and lower-educated individuals (P = 0.022). Non-employed individuals with higher ultra-processed food intake showed a decline in their PCS and MCS scores. While there was no significant difference in MCS score among different strata of lifestyle and socioeconomic status across tertiles of ultra-processed foods. CONCLUSIONS: Higher intake of ultra-processed foods was associated with poorer physical health, particularly among women, those with unhealthy lifestyles, and low socioeconomic conditions.

Improvement of glycemic indices by a hypocaloric legume-based DASH diet in adults with type 2 diabetes: a randomized controlled trial.

PURPOSE: The current study aimed to investigate the effects of legumes inclusion in the hypocaloric dietary approaches to stop hypertension (DASH) diet on fasting plasma glucose (FPG) and cardiometabolic risk factors in overweight and obese patients with type 2 diabetes over 16 weeks. Also, the modulatory effects of rs7903146 variant in the transcription factor 7 like 2 (TCF7L2) gene that is associated with the risk of diabetes, were assessed on these cardiometabolic risk factors. METHODS: This study was a randomized controlled trial. Three-hundred participants, aged 30-65 years, whose TCF7L2 rs7903146 genotype was determined, were studied. The participants were randomly assigned to receive either the hypocaloric DASH diet or a hypocaloric legume-based DASH diet. The primary outcome was the difference in FPG change from baseline until the 16-week follow-up between the two dietary interventions. The secondary outcomes were differences in insulin resistance and lipid profile changes between the dietary intervention diets. RESULTS: A reduction in FPG, insulin, homeostatic model assessment for insulin resistance (HOMA-IR), triglyceride, total cholesterol, and low-density lipoprotein cholesterol (LDL-C) was observed at week 16 in both hypocaloric dietary interventions. Compared to the DASH diet, the legume-based DASH diet decreased the FPG and HOMA-IR. There is no interaction between rs7903146 and intervention diets on glycemic parameters. CONCLUSION: The DASH diet, enrich in legumes, could improve the glycemic parameters in participants with type 2 diabetes, regardless of having rs7903146 risk or non-risk allele. REGISTRATION NUMBER OF CLINICAL TRIAL: Iranian Registry of Clinical Trials (IRCT) (code: IRCT20090203001640N17).

Effect of TCF7L2 on the relationship between lifestyle factors and glycemic parameters: a systematic review.

BACKGROUND: Among candidate genes related to type 2 diabetes (T2DM), one of the strongest genes is Transcription factor 7 like 2 (TCF7L2), regarding the Genome-Wide Association Studies. We aimed to conduct a systematic review of the literature on the modification effect of TCF7L2 on the relation between glycemic parameters and lifestyle factors. METHODS: A systematic literature search was done for relevant publications using electronic databases, including PubMed, EMBASE, Scopus, and Web of Science, from January 1, 2000, to November 2, 2021. RESULTS: Thirty-eight studies (16 observational studies, six meal test trials, and 16 randomized controlled trials (RCTs)) were included. Most observational studies had been conducted on participants with non-diabetes showing that TCF7L2 modified the association between diet (fatty acids and fiber) and insulin resistance. In addition, findings from meal test trials showed that, compared to non-risk-allele carriers, consumption of meals with different percentages of total dietary fat in healthy risk-allele carriers increased glucose concentrations and impaired insulin sensitivity. However, ten RCTs, with intervention periods of less than ten weeks and more than one year, showed that TCF7L2 did not modify glycemic parameters in response to a dietary intervention involving different macronutrients. However, two weight loss dietary RCTs with more than 1-year duration showed that serum glucose and insulin levels decreased and insulin resistance improved in non-risk allele subjects with overweight/obesity. Regarding artichoke extract supplementation (ALE), two RCTs observed that ALE supplementation significantly decreased insulin concentration and improved insulin resistance in the TT genotype of the rs7903146 variant of TCF7L2. In addition, four studies suggested that physical activity levels and smoking status modified the association between TCF7L2 and glycemic parameters. However, three studies observed no effect of TCF7L2 on glycemic parameters in participants with different levels of physical activity and smoking status. CONCLUSION: The modification effects of TCF7L2 on the relation between the lifestyle factors (diet, physical activity, and smoking status) and glycemic parameters were contradictory. PROSPERO REGISTRATION NUMBER: CRD42020196327.

The protective effects of dietary intake of flavonoids and its subclasses on metabolic syndrome incidence.

This study aimed to evaluate the association between the intake of total flavonoids and flavonoid subclasses and metabolic syndrome (MetS) risk and to assess the modulating effects of lifestyle factors on these associations. A total of 1915 participants from the Tehran Lipid and Glucose Study were followed-up during 2006-2008 and 2016-2018. Their dietary intake was assessed by a food frequency questionnaire at baseline and within three-year intervals afterward. Moreover, the modifying effect of weight gain on the association between total flavonoids and MetS was assessed by Cox regression analysis. Participants in the highest tertile of flavonoid, flavonol, and flavone had a significantly lower MetS risk as compared to those in the lowest tertile. Also, in participants with weight gain <7%, all flavonoid subclasses had a more pronounced risk-reducing effect. Overall, the total flavonoid, flavonol, and flavone reduced the risk of MetS; this association could be modified by weight gain.

The role of different lipid measures for incident hypertension during more than 12-year follow-up: Tehran Lipid and Glucose Study.

The associations of different lipid measures and related indices with incident hypertension during a median follow-up of 12·89 years were examined. Fasting levels of total cholesterol (TC), TAG, HDL-cholesterol and LDL-cholesterol, and related indices (TC/HDL-cholesterol and TAG/HDL-cholesterol) were determined in 7335 Iranian adults (men = 3270) free of hypertension, aged 39·0 (sd 13·2) years. Multivariate Cox proportional hazard regression was applied and lipid parameters were considered either as categorical or continuous variables. During follow-up, 2413 (men = 1126) participants experienced hypertension. Using the first quartile as reference, significant trends were found between quartiles of TAG, HDL-cholesterol, TC/HDL-cholesterol and TAG/HDL-cholesterol in multivariate models; moreover considering these measures as continuous variables, a 1 sd increase in each of these parameters was significantly associated with the risk of incident hypertension; the corresponding hazard ratios and CI were 1·06 (95 % CI 1·02, 1·10), 0·94 (95 % CI 0·89, 0·98), 1·04 (95 % CI 1·01, 1·09) and 1·04 (95 % CI 1·01, 1·07), respectively. The associations between lipid measures and incident hypertension did not change after excluding lipid lowering drug users and those with type 2 diabetes mellitus and these associations were independent of the categories of baseline blood pressure (P for interaction > 0·08). These findings indicate that TAG, TAG/HDL-cholesterol and TC/HDL-cholesterol were independently associated with higher risk, while HDL-cholesterol was associated with lower risk of incident hypertension.

Socioeconomic status and lifestyle factors modifies the association between snack foods intake and incidence of metabolic syndrome.

BACKGROUND: Intake of snack foods has been previously associated with an elevated risk of chronic disease; however, studies on snack foods and metabolic syndrome (MetS) while considering the modifying effect of socioeconomic status (SES) and lifestyle factors on this association are lacking. We aimed to investigate the association between snack foods intake and the MetS risk, and the mediatory effects of SES and lifestyle factors on the forenamed association among adults who participated in the Tehran Lipid and Glucose Study (2006-2018). METHODS: This is a prospective study of 1915 participants (male, 40.5%), aged 19-74 year who were free of MetS at baseline. Dietary intakes were gathered using a validated, semi-quantitative food frequency questionnaire at baseline (2006-2008), and with 3-year intervals afterwards. Alternative approach was used for snack foods from all available questionnaires during follow-up. Snack foods were divided into 4 categories, including total snacks, biscuits and cakes, candies and chocolate, and salty snacks. Total snack foods intake and its subgroup (serving/week) were modeled as tertiles. MetS was diagnosed according to the Joint Interim Statement criteria. Physical activity level (PAL) categorized as low/medium and high levels. Information regarding smoking (Smoker/Non-smoker), education (higher/lower education), and occupation (employed/non-employed) was gathered using questionnaire. The Cox regression was used, regarding interaction between snack foods, SES, and PAL on the MetS risk. RESULTS: A total of 591 incident MetS cases were diagnosed during 8.9 years of follow-up. The median total snack foods intake was 5.2 serving/week (IQR: 3.0-9.1). Total snack foods intake was positively associated with the MetS risk after adjusting for potential confounders (adjusted for age and gender, energy intake, total fiber intake, smoking status, PAL, education levels, family history of diabetes, family history of CVD events, and BMI). After adjustment for confounders, among snacks' subgroups, candies and chocolate intake was positively associated with MetS risk. Moreover, among lower-educated and non-employed participants, candies and chocolate intake was positively associated with the MetS risk, by 38 and 43% respectively. Stratification based on PAL resulted a positive association between intake of total snack foods and candies and chocolates and risk of MetS among participants with low PAL. CONCLUSION: Snack foods, especially candies and chocolate, increased the risk of MetS, among individuals with a low PAL.

Does the association between patterns of fruit and vegetables and metabolic syndrome incidence vary according to lifestyle factors and socioeconomic status?

BACKGROUND AND AIMS: The aim of this study is to investigate the association between the identified patterns of fruits and vegetables and metabolic syndrome (MetS) incidence, and to investigate whether lifestyle factors and socioeconomic status modify the effect of the patterns on MetS risk. METHODS AND RESULTS: We prospectively studied 1915 participants of the Tehran Lipid and Glucose Study, who were aged 19-74 years and followed up for dietary assessment using a validated, semi-quantitative food frequency questionnaire. After adjustment for confounding factors, total vegetable intake was inversely related to the risk of MetS. Total fruit and total fruit and vegetable were not associated with MetS risk. We identified four major patterns of fruits and vegetables by factor analysis: "fresh fruit pattern", "vegetable pattern", "dried fruit and cruciferous vegetable pattern", and "potatoes and fruit juice pattern". "Vegetable pattern" was negatively associated with MetS risk, and "potatoes and fruit juice pattern" increased the risk of MetS. Among participants with weight gain <7% during follow-up, all four identified patterns reduced MetS risk. When stratified by smoking, "vegetable pattern" and "dried Fruit and cruciferous vegetable pattern" lowered MetS risk among non-smokers. Stratification based on education resulted in MetS risk reduction across tertiles of "fresh fruit pattern" and "vegetable pattern". First and second tertiles of "dried fruit and cruciferous vegetable pattern" lowered MetS risk among educated participants, compared to the reference. CONCLUSIONS: The reduction in MetS risk caused by fruits and vegetables intake depends on the modifying effect of lifestyle and socioeconomic factors.

Inverse relation between fruit and vegetable intake and the risk of gestational diabetes mellitus.

Background: The aim of this study was to investigate the association of intakes of fruit, vegetable and dairy with gestational diabetes mellitus (GDM). Methods: This prospective study was conducted over a 17 month period, on a random sample of pregnant women (n = 1026), aged 18-45 y, in their first half of pregnancy, attending prenatal clinics in five hospitals' affiliated to universities of medical sciences in different districts of Tehran, Iran. Dietary intakes were assessed during gestational age ≤ 6 weeks using a 168-item validated semi-quantitative food frequency questionnaire. Between 24 and 28 weeks of gestation, all pregnant women underwent a scheduled 100 g 3-h oral glucose tolerance test. Diagnosis of GDM was based on criteria set by the American Diabetes Association. Results: Of 1026 study participants, 71 had GDM, with a mean age and pre-pregnancy BMI of 26.7 ± 4.3 y and 25.4 ± 4.5 Kg/m2, respectively. High fruit and vegetable intakes were negatively associated with GDM risk. Compared with women who consumed < 2.1 servings/day, odds ratio (ORs) for those who consumed ≥ 4.9 servings/day was 0.44 (95% CI: 0.20-0.93), after adjustment for confounding factors. Fruit and vegetable intakes were significantly and inversely associated with the GDM; ORs (95% CIs) for GDM among participants with the highest, compared to the lowest quartiles were 0.48 (0.18-0.89) for fruit and 0.46 (0.22-0.99) for vegetables intake. No association was found between dairy products and GDM. Conclusions: Fruit and vegetable consumption in women of reproductive age have beneficial effects in the prevention of GDM.

Non-soya legume-based therapeutic lifestyle change diet reduces inflammatory status in diabetic patients: a randomised cross-over clinical trial.

The present randomised cross-over clinical trial investigated the effects of two intervention diets (non-soya legume-based therapeutic lifestyle change (TLC) diet v. isoenergetic legume-free TLC diet) on inflammatory biomarkers among type 2 diabetic patients. A group of thirty-one participants (twenty-four women and seven men; weight 74.5 (SD 7.0) kg; age 58.1 (SD 6.0) years) were randomly assigned to one of the two following intervention diets for 8 weeks: legume-free TLC diet or non-soya legume-based TLC diet. The latter diet was the same as the legume-free TLC diet, except that two servings of red meat were replaced with different types of cooked non-soya legumes such as lentils, chickpeas, peas and beans over a period of 3 d per week. The intervention period was followed by a washout period of 4 weeks, after which the groups followed the alternate treatment for 8 weeks. Concentrations of inflammatory markers were measured at baseline and after the intervention periods. Compared with the legume-free TLC diet, the non-soya legume-based TLC diet significantly decreased high-sensitivity C-reactive protein, IL-6 and TNF-α in overweight diabetic patients. The replacement of two servings of red meat by non-soya legumes in the isoenergetic TLC diet for a period of 3 d per week reduced the plasma concentrations of inflammatory markers among overweight diabetic patients, independent of weight change.

Fruit and vegetable intake modifies the association between ultra-processed food and metabolic syndrome.

BACKGROUND: This prospective cohort study aimed to investigate the association between ultra-processed food (UPF) and the risk of metabolic syndrome (MetS), as well as to assess whether fruit and vegetable intake and weight change modify this association. METHODS: We included 1915 healthy participants who participated in the Tehran Lipid and Glucose Study (TLGS), all of whom had complete demographic, anthropometric, and dietary measurements. A validated food frequency questionnaire was used to assess UPF consumption based on the NOVA classification system. MetS was defined according to the Joint Interim Statement. Multivariable adjusted Cox regression was used to estimate hazard ratios (HRs) for MetS events across tertiles of UPF. The effect of fruit and vegetable consumption and weight change on this association was assessed using joint classification by Cox regression. RESULTS: UFP consumption showed no association with MetS risk after adjusting for confounders. However, after adjustment for dietary fiber, fruits, and vegetables, the highest tertile of UPF consumption was positively linked to MetS risk, compared to the lowest tertile. There was a significant interaction between fruit, vegetable, and dietary fiber intake and UPF consumption concerning the risk of MetS (All P values < 0.05). Among individuals consuming less than 248 g/day of fruit, the risk of MetS increased by 54% (confidence interval: 1.13-2.10) in the highest UPF tertile. Consuming vegetables and dietary fiber below the median (258 g/day and 42.2 g/day, respectively) increased the risk of MetS in the third tertile of UPF. However, consuming vegetables and fiber ≥ median intake, reduced the risk of MetS among those with the lowest UPF consumption. Furthermore, the risk of MetS was observed in the third tertile of UPF consumption among individuals with fruit and vegetable consumption < 537 g/day. UPF consumption was not associated with the risk of MetS in different weight change statuses. CONCLUSIONS: Consuming more fruits and vegetables mitigated the adverse effect of UPF on the risk of developing MetS.

The association between metabolic syndrome and insulin resistance with risk of cardiovascular events in different states of cardiovascular health status.

AIMS/INTRODUCTION: The aim was to examine the joint effect of metabolic syndrome (MetS) and insulin resistance (IR) with ideal cardiovascular health (iCVH) status on incident cardiovascular diseases (CVDs). MATERIALS AND METHODS: The study included 6,240 Iranian adults ≥30 years, free of prior cardiovascular disease. Ideal cardiovascular health was determined based on American Heart Association's Life Simple 7. Metabolic syndrome was defined according to the Joint Interim Statement Criteria, and insulin resistance was defined as HOMA-IR ≥1.85 in women and ≥2.17 in men. Multivariable Cox proportional hazard ratios (HRs) were applied to examine the impact of metabolic syndrome, and insulin resistance at various levels of iCVH status. RESULTS: During the median follow-up of 14.0 years, 909 cases of cardiovascular disease occurred. Metabolic syndrome and insulin resistance were significantly associated with incident cardiovascular disease events. In the poor and intermediate status, metabolic syndrome increased cardiovascular disease events with HRs of 1.83 and 1.57, respectively; the corresponding values for insulin resistance in the mentioned categories were 1.91 and 1.25, respectively (P values < 0.05). In the intermediate and poor iCVH status, hypertriglyceridemia was linked to a 40% and 35% higher risk of cardiovascular disease, the corresponding values for low HDL-C was 20% and 60%, respectively (P values < 0.05). Although adding metabolic syndrome, its dyslipidemia and insulin resistance to iCVH status in both poor and intermediate status significantly improve the prediction of cardiovascular disease using net reclassification improvement (P values < 0.05), the value of C-index did not change. CONCLUSIONS: Metabolic syndrome and the dyslipidemia component had a negligible but significant improvement in the prediction of cardiovascular disease among individuals with non-optimal iCVH status.

Dietary polyphenols and metabolic syndrome among Iranian adults.

AIM: The aim of this study was to investigate the association between total polyphenol intake, its subclasses (including flavonoids, phenolic acids, stilbenes and lignans), and the metabolic syndrome (MetS). METHODS: This population-based cross-sectional study was conducted on a representative of 2618 adults, aged 19 to 84 years. Dietary intake was assessed using a validated food-frequency questionnaire and intakes of total polyphenol and four main subclasses of polyphenol including flavonoids, phenolic acids, stilbenes and lignans were determined. RESULTS: Higher consumption of flavonoid intakes was associated with lower odds of enlarged waist circumference, hypertriglyceridemia, low HDL cholesterol, hyperglycemia, hypertension and MetS. Subjects in the highest quartile of lignan intakes had higher odds of having hypertriglyceridemia and hyperglycemia. Subjects in the highest quartile of stilbene intakes had higher odds of having hypertension. CONCLUSION: Intakes of selected subclasses of polyphenol such as flavonoids are associated with a lower prevalence of MetS among Tehranians.

Effect of weight change on the association between overall and source of carbohydrate intake and risk of metabolic syndrome: Tehran lipid and glucose study.

BACKGROUND: In this prospective cohort study, we aimed to evaluate the association between dietary carbohydrates, whole grains, refined grains, and simple sugar with the risk of metabolic syndrome (MetS) and assess the effect of weight change on these associations. METHODS: This study was conducted within the framework of the Tehran Lipid and Glucose Study (TLGS). We included 1915 healthy participants with complete demographic, anthropometric and dietary measurements, among whom 591 developed MetS during 8.9 years of follow-up. Intake of dietary carbohydrates, whole grains, refined grains, and simple sugar was assessed with a validated semi-quantitative food frequency questionnaire. Multivariable adjusted Cox regression was used to estimate hazard ratios (HRs) for MetS events across tertiles of dietary variables. Using joint classification, the effect of weight change on the association between dietary variables and risk of MetS was assessed by Cox regression. RESULTS: Carbohydrate intake was not associated with the risk of MetS in multivariable-adjusted models. Whole grains intake was inversely associated with the risk of MetS (HR: 0.78, CI: 0.63-0.98), while this association disappeared after adjustment for weight change. The risk of MetS increased by 11% (1.11, 1.09-1.14) for each 3% energy increment from simple sugar, and by 5% (1.05, 1.03-1.08) for each 1 serving/day increment in refined grains. Consumption of refined grains increased the risk of MetS; an effect modification of this association was found by weight change. Among subjects with weight loss, intake of refined grains < median intake decreased the risk of MetS (0.59, 0.41-0.87). However, consumption of refined grains ≥ median intake increased the risk of MetS in individuals with weight gain (1.47, 1.08-2.01). Simple sugar was positively associated with an increased risk of MetS, after adjustment for weight change (3.00, 2.37-3.82). In joint classification, intake of simple sugar greater than median intake increased the risk of MetS, independent of weight change. CONCLUSION: Our findings suggest an effect modification by weight change on the association between carbohydrates, and refined grains intake and the risk of MetS. Weight loss along with lower consumption of carbohydrates, and refined grains reduced the risk of MetS. However, simple sugar intake, regardless of weight change, was associated with an increased risk of MetS.

Magnesium intake and prevalence of metabolic syndrome in adults: Tehran Lipid and Glucose Study.

OBJECTIVE: We examined the association of metabolic syndrome (MetS) and its components with dietary intakes of Mg in Tehran adults. DESIGN: In a cross-sectional study, dietary intakes were assessed using a valid and reliable FFQ. MetS was defined according to the modified guidelines of the National Cholesterol Education Program Adult Treatment Panel III. Waist circumference (WC) was coded according to the newly introduced cut-off points for Iranian adults (≥95 cm for both genders). SETTING: Participants of the Tehran Lipid and Glucose Study (2006-2008). SUBJECTS: Adults (n 2504; 1120 men and 1384 women) aged 18-74 years. RESULTS: The mean age of participants was 40·8 (SD 14·6) years and 38·2 (SD 13·5) years for men and women, respectively. The reported mean intake of Mg was 349 (SD 109) mg/d. After adjustment for confounding factors, dietary Mg intake was inversely associated with fasting blood glucose (ß = -0·08, P = 0·006), TAG (ß = -0·058, P = 0·009) and WC (ß = -0·013, P = 0·006); however, there were no associations between dietary Mg and diastolic blood pressure, systolic blood pressure or HDL cholesterol. An association was observed between MetS Z-score and Mg intake (crude ß = -0·017, P = 0·001), independent of age, gender, smoking, physical activity and BMI; this association was attenuated following further adjustment for dietary factors and menopausal status (ß = -0·034, P = 0·061). CONCLUSIONS: Our findings suggest a significant inverse association between dietary Mg, MetS and its components.

Effect of dietary approaches to stop hypertension (DASH) diet, high in animal or plant protein on cardiometabolic risk factors in obese metabolic syndrome patients: A randomized clinical trial.

AIMS: This study aimed to investigate the effect of replacing plant proteins with animal proteins in the dietary approaches to stop hypertension (DASH) diet on cardiometabolic risk factors in obese metabolic syndrome participants. METHODS: In this double-blind randomized controlled clinical trial, 90 obese patients with metabolic syndrome, aged 30-70 years were randomly allocated into the DASH diet based on plant or animal proteins for 8 weeks. Fasting blood samples were collected to assess the biochemical markers. Also, blood pressure, weight, and waist circumference (WC) were measured at the beginning and end of the trial. RESULTS: The participants in both groups experienced significant reductions in the fasting plasma glucose (FPG), systolic blood pressure (SBP) and diastolic blood pressure (DBP), triglyceride (TG) concentrations, weight and WC. However the reduction in FPG and SBP was higher in the plant-based DASH group, compared to the animal-based DASH group, after adjustment for weight change. No significant changes were found within or between groups with regard to total cholesterol, LDL-C, HDL-C. CONCLUSIONS: Substituting plant proteins with animal proteins in the DASH diet improves FPG and SBP in obese individuals with metabolic syndrome, independent of weight change. IRCT registration number: IRCT20090203001640N16.

Relation of dietary insulin index and dietary insulin load to metabolic syndrome depending on the lifestyle factors: Tehran lipid and glucose study.

AIM: The hypothesis of the effect of the insulinogenic effects of diet on the development of cardiovascular diseases has been proposed, but the findings of previous studies are very contradictory. We investigated the association between dietary insulin index (DII) and dietary insulin load (DIL), and metabolic syndrome (MetS) risk. Another objective was to examine the extent to which lifestyle (physical activity, smoking status, and weight change) and sex influence the relationship between DII, DIL, and MetS risk. MATERIALS AND METHODS: We followed 1915 participants in the Tehran Lipid and Glucose Study. DIL and DII were calculated based on a validated food frequency questionnaire. Weight change was measured, and participants were categorized into > 3% weight loss, weight stable (± 3%), and > 3% weight gain. By joint classification, the association between DII and DIL (< median and ≥ median) and risk of MetS was assessed according to weight change, sex, physical activity levels, and smoking status. Cox proportional hazards models were used to estimate the HRs (95% CI), adjusting for potential confounders. RESULTS: During 8.9 years of follow-up, among 1915 participants, we documented 591 new cases of MetS. DII and DIL were not associated with MetS risk in the crude and adjusted models. However, DIL and DII were associated with weight gain (≥ 3%). In the crude model, DIL and DII were associated with a higher risk of weight gain [HR: 1.74: 95% CI 1.50-2.03, and 1.70 (1.46-1.98), respectively]. These associations remained significant after further adjustment for confounders. The HRs were 1.61 (1.35-1.92) for DIL and 1.64 (1.39-1.93) for DII. Among men, women, participants with low physical activity levels, and smokers, the risk of MetS, independent of DIL and DII, only increased in a participant with weight gain. In women with weight stability, DIL and DII, higher than the median, were positively associated with MetS risk. CONCLUSION: Our findings suggest that the association between MetS risk and a hyperinsulinemic diet depended on weight change.

Associations between dietary antioxidant intakes and cardiovascular disease.

Cardiovascular disease (CVD), as the leading cause of death worldwide, is the collective term named for disorders afflicting the blood vessels and heart. Inflammation and enhanced oxidative stress have been shown as fundamental risk factors in the onset and progression of CVD. Chronic inflammatory conditions attenuate blood levels of antioxidants because of the continuous generation of elevated levels of reactive oxygen species (ROS). A sufficient intake of antioxidants is also suggested to beneficially interfere with CVD by quenching ROS. Antioxidant vitamins and minerals, such as vitamins A, E, and C, and zinc may slow the development and progression of CVD. This study aimed at investigating the association between daily consumption of dietary vitamins A, E, and C, and zinc and the incidence of CVD. Eligible adults (n = 5102) aged ≥ 30 years, were selected from the participants of the Tehran lipid and glucose study with an average follow-up of 5.3 years. Dietary intake was assessed using a valid and reliable semi-quantitative food frequency questionnaire. Anthropometrics and biochemical variables were evaluated at baseline and follow-up examinations. Multivariable Cox proportional hazard regression models were used to estimate the development of CVD associated with total intakes of vitamins A, E, and C, and zinc. This study was conducted on 2253 men and 2849 women aged 47.0 ± 11.6 and 45.6 ± 10.5 years, respectively. The main sources of dietary vitamins A, E, and C and zinc were fruits, vegetables, and legumes. Risk of CVD decreased from quartile 1 to quartile 4 for vitamin E intake (HR 1.00, 0.91, 0.77, and 0.57; Ptrend = 0.03). The association between the risk of CVD and quartiles of vitamins A, and C and zinc intake was not statistically significant. Our study suggests an inverse association between vitamin E intake and the risk of CVD, emphasizing the potential protective role of fruit and vegetable in the prevention of CVD.

Effect of legumes in energy reduced dietary approaches to stop hypertension (DASH) diet on blood pressure among overweight and obese type 2 diabetic patients: a randomized controlled trial.

BACKGROUND: This study aimed to investigate the effects of legumes in dietary approaches to stop hypertension (DASH) on blood pressure and urinary sodium and potassium in participants with type 2 diabetes. We further investigated whether changes in individual dietary food groups in the DASH diet contribute to blood pressure. METHODS: Participants were randomized to the traditional DASH diet (n = 150) or the legume-based DASH diet (n = 150). Blood pressure and urinary sodium and potassium were measured at baseline and after 16-week interventions. An intention-to-treat approach with multiple imputations of missing data was applied. The restricted cubic spline (RCS) was applied to assess the linearity and explore the shape of the relationship between the changes in food groups and systolic blood pressure (SBP) in the two intervention groups. RESULTS: A reduction in SBP and urinary sodium was observed at week 16 in both dietary interventions, and this reduction was more significant in the legume-based DASH diet, than in the DASH diet. In the legume-based DASH diet, SBP decreased with the legume intake of more than 95.8 g/day (P nonlinear < 0.001). The multivariable RCS analysis showed a U-shaped relationship of refined grains, an L-shaped relationship of fruits, and a linear relationship of sweet, energy, sodium and vegetables intake with SBP. CONCLUSIONS: The DASH diet, enriched in legumes, could improve SBP in participants with type 2 diabetes. In DASH diet, the balance of consumption of refined grains and fruits along with higher vegetable consumption and lower sweet, sodium and energy intake reduced the SBP. TRIAL REGISTRATION: IRCT20090203001640N17.