Nutrition and diabetes, cardiovascular and chronic kidney diseases: findings from 20 years of the Tehran lipid and glucose study

Context: the high prevalence of chronic diseases can be prevented or managed by specific changes in lifestyle patterns of individuals of which dietary factors is emphasized. The objective of this study was to review all findings of the Tehran Lipid and Glucose Study regarding validity and reliability of food frequency questionnaire [FFQ], evaluating dietary quality and association of dietary factors in relation to diabetes, dysglycemia, cardiovascular [CVD] and chronic kidney disease [CKD]

Evidence Acquisition: related documents were searched through PubMed and Scopus databases, in English language from 2000 to 2017. Finally, 52 relevant documents were eligible for inclusion in this review

Results: the FFQ proved to be an acceptable tool for assessing nutrient and food group intakes and rank individuals accurately according to the levels of their dietary intakes. After 8 years of follow-up, the western dietary pattern [DP] was fairly stable but there was instability of traditional Iranian DP. DPs of over two-thirds of Tehranian populations were not in accordance with the dietary recommendations. Higher dietary scores of variety and healthy DPs were also associated with reduced odds of dysglycemia. The main dietary factor related to increased risk of CVDin our population was western DP. Patterns of amino acid intakesmaycontribute to the development of CVD. Higher intakes of several micronutrients and macronutrients, DPs and some vegetables decrease the risk of CKD. In conclusion DPs of most Tehranian adults need improvement

Conclusions: this review showed that higher adherence to healthy food choices was associated with reduced odds of dysglycemia and CVD. Dietary sources of renal-protective nutrients should be encouraged among the general population

Nutrition and cardio-metabolic risk factors: findings from 20 years of the Tehran lipid and glucose study

Context: genetic and environmental factors contribute to the incidence of metabolic syndrome [MetS]. This study aimed to review all findings of studies conducted in framework of the Tehran lipid and glucose study [TLGS] regarding the association of dietary factors with cardio-metabolic risk factors

Evidence Acquisition: all English-language studies were searched using PubMed and Scopus databases from 2000 to 2017. Finally, 105 relevant papers were included in this review

Results: whole grains, legumes, nuts and healthy dietary patterns [DPs] reduced risk of MetS, while white rice, salty/sweet snacks increased this. The western DP had a significant interaction with APOC3, APOA1 and MC4R polymorphisms in relation to MetS. After 6.5 years of follow-up, odds of reaching menarche

Conclusions: higher adherence to healthy food choices was associated with reduced odds of MetS, abdominal obesity, dyslipidemia and hypertension. The western DP accentuated the association of polymorphisms with MetS

Metabolic syndrome: findings from 20 years of the Tehran lipid and glucose study

Context: in recent decades, investigations have been focused on the definition, incidence and predictors of metabolic syndrome [MetS] in Iranians. This study aimed to review systematically investigations on MetS, conducted among the Tehran lipid and glucose study [TLGS] participants

Evidence Acquisition: literature on MetS documented by TLGS studies published from 2000 to 2017 were searched using Pubmed and Scopus database in English language with a combination of following keywords: Metabolic syndrome, TLGS

Results: the harmonized definition of MetS was confirmed, based on the estimated cut point of waist circumference [WC] >/= 95 cm for both genders in Iran. The incidence rate was 550.9/10000 person/years, lower among women [433.5/10000] than men [749.2/10000]. The prevalence of abdominal obesity, high triglycerides [TG], low high density lipoprotein cholesterol [HDL-C], high blood pressure [BP], and high fasting blood glucose [FBG] was 30, 46, 69, 34, and 12%, respectively. The prevalence of MetS in adolescents was 10.1% with no significant difference between boys and girls [10.3% in boys and 9.9% in girls]. A strong association of WC [OR: 2.32, CI: 2.06 - 2.59] and TGs [OR: 1.95, CI: 1.65 - 2.11] with development of MetS was found. In adolescent boys, WC had the highest OR for MetS risk. WHO-defined MetS was a significant predictor of total and cardiovascular mortality both in men [HR: 1.66, CI: 1.23 - 2.24; HR: 1.93, CI: 1.26 - 2.94] and women [HR: 2.01, CI: 1.39 - 2.88; HR: 2.71, CI: 1.44 - 5.09]

Conclusions: our results indicate high incidence of MetS in Tehranian adults and adolescents; high WC also appears to be a strong predictor of MetS. All definitions of MetS predicted cardiovascular disease

nitrate-nitrite-nitric oxide pathway: findings from 20 years of the Tehran lipid and glucose study

Context: we describe here the contributions of the Tehran lipid and glucose study [TLGS] to understanding different aspects of the nitrate [NO3]-nitrite [NO2]-nitric oxide [NO] pathway in health and disease

Evidence Acquisition: all English-language documents from the TLGS, focused on NO pathway were searched using the PubMed, Scopus, and Embase databases

Results: reference values of serum concentrations of NO metabolites [nitrate + nitrite or NOx] were 11.5 - 76.4, 10.1 - 65.6, and 10.3 - 66.8_mol/L in men, women, and the total population, respectively. Circulating NOx was affected by age, smoking habits, menopause status, thyroid hormones, and various pathologic conditions. Elevated serum NOx was related to increased incidence of metabolic syndrome [odds ratio [OR] = 1.75, 95% confidence interval [CI] = 1.19 - 2.59], hypertriglyceridemic-waist phenotype [OR = 1.39, 95% CI = 1.05 - 1.93], chronic kidney disease [OR = 1.86, 95% CI = 1.10 - 3.14] in women, and cardiovascular disease [hazard ratio [HR] = 1.35, 95% CI = 1.01 - 1.80] in the total population. In participants with low vitamin C intake, higher intakes of NO2 [ >/= 8.77 mg/d] were accompanied with increased risk of diabetes [HR = 2.43, 95% CI = 1.45 - 4.05]. A decreased risk of hypertension [OR = 0.58, 95% CI = 0.33 - 0.98] and chronic kidney disease [OR = 0.50, 95% CI = 0.24 - 0.89] was observed in response to higher intakes of NO2

Conclusions: circulating NOx is associated with and could predict the risk of metabolic disorders in a general population. Moreover, dietary NO3/NO2 exposure from usual diets seems to contribute to development of noncommunicable diseases

Associations between Dietary Acid-Base Load and Cardiometabolic Risk Factors in Adults: The Tehran Lipid and Glucose Study

BACKGROUND: In this study we investigated the associations of dietary acid-base load, identified by potential renal acid load (PRAL) and protein to potassium (Pro:K) ratio, with cardiometabolic risk factors in Tehranian adults. METHODS: A cross-sectional study was conducted within the framework of the fourth phase of the Tehran Lipid and Glucose Study (2009 to 2011) on 5,620 men and women aged 19 to 70 years. Dietary data were collected by a trained dietitian using a validated, 147-food item, semi-quantitative food frequency questionnaire, and dietary PRAL and Pro:K ratio were calculated. Multiple linear regression models with adjustment for potential confounding variables were used to evaluate the associations of dietary acid-base load with anthropometric measures, blood pressure, serum triglycerides, high density lipoprotein cholesterol (HDL-C), serum creatinine, and fasting blood glucose. RESULTS: The mean+/-SD age of the participants was 39.8+/-12.8 years and 54% of participants were women. Mean+/-SD PRAL was -22.0+/-29.1; mean PRAL was -15.6 in men and -26.8 in women. Dietary PRAL was associated with weight (beta=0.098, P<0.001), waist circumference (beta=0.062, P<0.01), serum triglycerides (beta=0.143, P<0.01), HDL-C (beta=-0.11, P<0.01), diastolic blood pressure (beta=0.062, P<0.01), and serum creatinine (beta=0.142, P<0.001). Pro:K ratio was associated with weight (beta=0.055, P<0.001), waist circumference (beta=0.04, P<0.01), serum HDL-C (beta=-0.06, P<0.01), serum triglycerides (beta=0.03, P<0.05), diastolic blood pressure (beta=0.026, P<0.05), and serum creatinine (beta=0.07, P<0.01). CONCLUSION: A more acidic dietary acid-base load may be a risk factor for the development of metabolic disorders.

Helicobacter pylori Stool Antigen Levels and Serological Biomarkers of Gastric Inflammation are Associated with Cardio-Metabolic Risk Factors in Type 2 Diabetic Patients

BACKGROUND: Helicobacter pylori infection and subsequent gastric inflammation have been proposed as risk factors for the development of insulin resistance and cardiovascular disease. In this study we assessed the possible association of H. pylori bacterial load, and serum biomarker of gastric inflammation with cardiometabolic risk factors in diabetic patients. METHODS: In this cross-sectional study, 84 H. pylori-infected type 2 diabetic patients were assessed for anthropometrics, biochemical and clinical measurements. Pearson correlation test, linear, and logarithmic regression curve estimation models were used to assess the association of H. pylori stool antigen (HpSAg) levels, and pepsinogen I (PGI) to pepsinogen II (PGII) ratio with fasting serum glucose, insulin, serum lipid and lipoprotein parameters, malondialdehyde, high-sensitive C-reactive protein (hs-CRP), systolic and diastolic blood pressure, body weight, waist circumference and lipid accumulation product (LAP) index. RESULTS: The mean age of participants was 54+/-10 years, and 44% were men. Mean HpSAg levels and PGI/PGII ratio were 0.24+/-0.23 microg/mL and 9.9+/-9.0, respectively. Higher HpSAg as well as lower PGI/PGII was correlated with higher anthropometric measures and LAP. A significant negative correlation between PGI/PGII ratio and blood pressure (r=-0.21 and r=-0.22, systolic and diastolic, respectively, P<0.05), serum insulin (r=-0.17, P=0.05), and hs-CRP (r=-0.17, P=0.05) was observed. A significant linear association between PGI/PGII ratio with serum triglycerides (beta=-0.24, P<0.05), serum high density lipoprotein cholesterol (HDL-C; beta=0.43, P<0.01), and triglycerides/HDL-C ratio (beta=-0.28, P<0.05) were observed. CONCLUSION: Higher H. pylori bacterial load and lower PGI/PGII ratio was associated with higher levels of cardiometabolic risk factors in H. pylori infected type 2 diabetic patients.

Sugar-Sweetened Beverage Consumption Is Associated with Metabolic Syndrome in Iranian Adults: Tehran Lipid and Glucose Study

BACKGROUND: Metabolic syndrome (MetS), a cluster of multiple metabolic abnormalities, is one of the major public health challenges worldwide. The current study was conducted to evaluate the association between sugar-sweetened beverage (SSB) consumption and MetS and its components in Iranian adults. METHODS: This cross-sectional study was conducted among 5,852 men and women, aged 19 to 70 years, who participated in the fourth phase (2009 to 2011) of the Tehran Lipid and Glucose Study. Demographics, anthropometrics, biochemical measurements, and blood pressure (BP) were assessed and MetS was defined by National Cholesterol Education Program Adult Treatment Panel III definition. Frequency and quantity of SSB intakes including carbonated drinks and synthetic fruit juices were collected using a validated semiquantitative food frequency questionnaire. RESULTS: Mean age of participants (43%, men) was 40.6+/-12.9 years. Significant positive associations between SSBs and waist circumference, triglyceride level, systolic and diastolic BP in the third and fourth quartile of SSBs were observed, after adjustment for all potential confounding variables. The odds of MetS in the third and fourth quartiles compared to the first quartile category of SSBs was 1.21 (95% confidence interval [CI], 1.01 to 1.45) and 1.30 (95% CI, 1.06 to 1.58), respectively (P for trend=0.03). The odds of MetS, abdominal obesity, low high density lipoprotein cholesterol and elevated BP had increasing trends across increasing of SSB consumption (P for trend <0.05). CONCLUSION: Higher intake of SSBs was associated with the higher odds of MetS in adults. It is suggested that reducing consumption of SSBs could be a practical approach to prevent metabolic abnormalities.

[ effect of consumption of unhealthy snacks on diet and the risk of metabolic syndrome in adults: Tehran lipid and glucose study, Iran]

Unhealthy snacks contain high amounts of calories, simple sugars, fat, cholesterol, salt, additives, and conservatives. Increased consumption of these unhealthy snacks is one of the underlying factors for the prevalence of overweight, obesity, and metabolic disorders. In this study, we investigated the effects of unhealthy snacks on diet and the risk of metabolic syndrome after 3-years of follow-up in Tehranian adults. This longitudinal study was conducted within the framework of the Tehran Lipid and Glucose Study, between 2006-2008 and 2009-2011, on men and women in Tehran, Iran. Dietary intakes of participants were measured using a validated semi-quantitative food frequency questionnaire at baseline. Biochemical and anthropometric measurements were assessed at baseline and 3 years later. Multiple logistic regression models with adjustment for confounding factors were used to estimate the occurrence of metabolic syndrome [MetS] in each quartile of unhealthy snacks. The mean age of participants was 37.8 +/- 12.3 years, and the mean of body mass index was 26.0 +/- 4.5 kg/m2. Moreover, 39% of the participants were male. Daily energy intake, dietary energy density, and total fat and sodium intake were higher in the fourth quartile of unhealthy snacks consumption. There was a significant decreasing trend in dietary intake of carbohydrate, calcium, zinc, selenium, and fiber parallel to increase in consumption of energy-dense snacks. Participants who were in the highest quartile of energy intake from unhealthy snacks consumed less whole grains, vegetables, and dairy products. After adjustment for potential confounders, the risk of metabolic syndrome had a significant positive association with salty snacks consumption, and a non-significant positive association with consumption of candies, chocolate, and soft drinks. Increased daily energy intake from unhealthy snacks could be a risk factor for the occurrence of metabolic syndrome

Lipid Accumulation Product Is Associated with Insulin Resistance, Lipid Peroxidation, and Systemic Inflammation in Type 2 Diabetic Patients

BACKGROUND: Lipid accumulation product (LAP) is a novel biomarker of central lipid accumulation related to risk of diabetes and cardiovascular disease. In this study, we assessed the association of LAP with glucose homeostasis, lipid and lipid peroxidation, and subclinical systemic inflammation in diabetic patients. METHODS: Thirty-nine male and 47 female type 2 diabetic patients were assessed for anthropometrics and biochemical measurements. LAP was calculated as [waist circumference (cm)-65]x[triglycerides (mmol/L)] in men, and [waist circumference (cm)-58]x[triglycerides (mmol/L)] in women. Associations of LAP with fasting glucose, insulin, insulin resistance index, lipid and lipoprotein levels, malondialdehyde, and high-sensitive C-reactive protein (hs-CRP) were assessed. RESULTS: Mean age and LAP index were 53.6+/-9.6 and 51.9+/-31.2 years, respectively. After adjustments for age, sex and body mass index status, a significant positive correlation was observed between LAP index and fasting glucose (r=0.39, P<0.001), and homeostasis model assessment of insulin resistance (r=0.31, P<0.05). After additional adjustment for fasting glucose levels, antidiabetic and antilipidemic drugs, the LAP index was also correlated to total cholesterol (r=0.45, P<0.001), high density lipoprotein cholesterol (HDL-C) levels (r=-0.29, P<0.05), triglycerides to HDL-C ratio (r=0.89, P<0.001), malondialdehyde (r=0.65, P<0.001), and hs-CRP levels (r=0.27, P<0.05). CONCLUSION: Higher central lipid accumulation in diabetic patients was related to higher insulin resistance, oxidative stress and systemic inflammation.

[ role of dietary polyphenols on attenuation of cardiovascular complications in type 2 diabetes: a review of studies]

Type 2 diabetes is a common metabolic disorder accompanied by increased risk of cardiovascular diseases, along with increased morbidity and mortality. In recent years, epidemiological evidence and clinical studies have indicated that dietary polyphenols and phytochemical-rich foods have key role in prevention of cardiovascular diseases, especially coronary heart disease and myocardial infarction. The current review was conducted to investigate the mechanism of the effects of polyphenols in natural foods on prevention of diabetes-induced cardiovascular diseases. "polyphenols", "phenolic acids", "anthocyanins", "flavonoids", and "lignans" in combination with "type 2 diabetes", "insulin resistance", "cardiovascular disease", "endothelial dysfunction", "oxidative stress", "inflammation", "lipid disorders", and "hypertension" were used as key words for search in PubMed between 1990 and 2013. Cellular studies, animal models and clinical trials with appropriate design, and review article with high quality were used. Dietary polyphenols have high potential to improve lipid profiles through decrease in digestion and ingestion of dietary fats, increase in turnover and excretion of cholesterol, reduction of synthesis of atherogenic apo lipoproteins, and inhibition of cholesterol and triglycerides synthesis. These compounds protect vascular endothelium against oxidative damages and inflammatory processes, improve function of vascular endothelium, modify the pathways related to platelets and coagulation, and even protect cardiac tissue and improve myocardial hemodynamics. Higher consumption of foods containing polyphenols and using polyphenol-rich natural extract can be useful in decreasing the risk of development of cardiovascular diseases in type 2 diabetic patients.

Fast food consumption in Iranian adults; dietary intake and cardiovascular risk factors: Tehran lipid and glucose study

Although fast food consumption has drastically increased in Iran in recent years; there is a paucity of data in relation to the association between fast food consumption, dietary intake, and cardiovascular risk factors. This study aims to determine fast food consumption status among young and middle-aged Iranian adults, and to assess its impact on dietary intake and cardiovascular disease [CVD] risk factors. This cross-sectional population-based study was conducted on 1944 young and middle-aged adults [840 men and 1104 women], who participated in the Tehran Lipid and Glucose Study [2006-2008]. We collected dietary data by using a validated 168 item, semi-quantitative food frequency questionnaire. Total fast food consumption was calculated by summing up weekly consumption of the most commonly consumed fast foods in Iran. Mean consumption of fast food was 161g/week [95% CI: 147-175] for young adults and 108 g/week [95% CI: 101-115] for middle-aged adults. Mean dietary intakes of energy, fat, saturated fat, cholesterol, sodium, meat, and soft drinks increased significantly [P < 0.05], while carbohydrate and refined grain consumption decreased [P < 0.01] across tertiles of fast food in both age groups. In young adults, dietary energy density and protein intake increased significantly [P < 0.01] where as intake of non-starchy vegetables and carotenoids decreased [P < 0.05]. In middle-aged adults dietary intakes of fiber, folate, calcium, and fruits significantly decreased across fast food tertiles [P < 0.05]. After adjustment for confounders, there was an association between fast food consumption and body mass index [BMI; beta = 0.104; P < 0.01] and waist circumference [WC; beta= 0.083; P < 0.01] in young adults, and serum triglycerides [beta = 0.072; P < 0.05], high density lipoprotein cholesterol [HDL-C; beta = -0.051; P < 0.05], and atherogenic index of plasma [beta = 0.056; P < 0.05] in middle-aged adults. The results show that increased consumption of fast foods is associated with poor dietary intake and some of the CVD risk factors in Iranian adults