Association of ideal cardiovascular health metrics with incident low estimated glomerular filtration rate: More than a decade follow-up in the Tehran Lipid and Glucose Study (TLGS)

AIMS

To evaluate the association between ideal cardiovascular health metrics (ICVHM) and incident low estimated glomerular filtration rate (eGFR) among the Iranian population.

METHODS

The study population included 6927 Iranian adults aged 20-65 years (2942 male) without prevalent low eGFR [i.e., eGFR < 60 ml/min/1.73 m2] and free of cardiovascular disease. The ICVHM was defined according to the 2010 American Heart Association. The multivariable Cox proportional hazards regression analysis was used to calculate the hazard ratios (HRs) of ICVHM both as continuous and categorical variables.

RESULTS

Over the median of 12.1 years of follow-up, we found 1259 incident cases of low eGFR among the study population. In this population, ideal and intermediate categories of body mass index (BMI) and blood pressure (BP) and only the ideal category of fasting plasma glucose (FPG) significantly decreased the risk of developing low eGFR; the corresponding HRs and (95% confidence intervals) were (0.87, 0.77-0.99), (0.84, 0.76-0.99), (0.79, 0.68-0.93), (0.70, 0.60-0.83) and (0.76, 0.64-0.91). Also, one additional ICVHM was associated with a reduced risk of low eGFR for the global (0.92, 0.88-0.97) and biological cardiovascular health (0.88, 0.82-0.93) in these participants. A sensitivity analysis using the interval-censoring approach demonstrated that our method is robust, and results remained essentially unchanged. In a subgroup population with dietary data (n = 2285), we did not find the beneficial impact of having intermediate/ideal categories of nutrition status compared to its poor one on incident low eGFR.

CONCLUSION

We found a strong inverse association between having higher global ICVHM with incident low eGFR among the non-elderly Iranian population; the issue is mainly attributable to normal BP, BMI, and FPG levels.

Dietary Intakes of Choline and Betaine and Incidence of Type 2 Diabetes: Tehran Lipid and Glucose Study

Background: Our knowledge for the possible link between choline and betaine and the risk of type 2 diabetes (T2D) is very limited and contradictory. This study aimed to investigate the prospective association of dietary choline and betaine intakes with the risk of T2D in a group of Tehranian adults. Methods: In this prospective study, 6022 eligible subjects aged ≥18 years were chosen from the participants of the Tehran Lipid and Glucose Study in a secondary analysis. Diet was assessed based on a valid and reliable semiquantitative food frequency questionnaire. At baseline and follow-up examinations, biochemical and anthropometric variables were assessed. Multivariable Cox proportional hazard regression models was used to estimate the new onset of T2D concerning choline and betaine intake. Results: The mean age ± SD of 2707 men and 3315 women were, respectively, 41.4 ± 14.2 and 39.1 ± 13.1. During a median follow-up of 6.63 years, 528 cases of T2D incidence were diagnosed. Participants with a higher intake of choline had a higher intake of protein, fiber, and B12 and a lower intake of energy and carbohydrates. After controlling of confounders a significant positive association was observed between choline intake and the hazard ratio (HR) of T2D across quartiles of choline intake [HR (CI) in the fourth quartile: 1.25 (1.14-1.38), P trend = 0.01], but this significant finding was not reported for betaine intake. For every 100 milligram increase in choline consumption, the HR of T2D increased significantly in all age, sex, and BMI subgroups. Conclusions: Choline consumption increased the risk of T2D in total population and subgroups. No statistically significant association was found between dietary betaine intake and the risk of T2D in total population and subgroups.

Interaction of common variants of FTO gene and Dietary Inflammatory Index on obesity measures: Tehran Lipid and Glucose Study

Background

This study aimed to examine the interaction of Dietary Inflammatory Index (DII) and fat mass and obesity-associated gene (FTO) single-nucleotide polymorphisms (SNPs) on change in obesity measures.

Methods

A total of 4480 participants from the Tehran Lipid and Glucose Study were selected. DII was calculated using a Food Frequency Questionnaire. The FTO SNPs rs8050136, rs14211085 and rs1121980 were selected. Changes in obesity measures were calculated.

Results

In individuals with risk allele of FTO SNP rs8050136, greater adherence to DII was associated with increased odds of higher waist circumference (WC) (OR, Q1-Q4: 1, 0.87, 0.88, 0.94; P trend=0.01), but deceased odds of waist to hip ratio (WHR) (OR, Q1-Q4: 1, 0.85, 0.76, 0.70; P trend=0.01). Moreover, higher score of DII was significantly related to elevated odds of having high Visceral Adiposity Index (VAI) in individuals with wild-type genotype of FTO SNPs. For changes in WC, a significant interaction was identified between FTO rs1421085 and DII; the second quartile of DII was associated with increased odds of having a high WC in carriers of wild variant (TT genotype) of rs1421085 (OR 1.43; 95% CI 1.04 to 1.97), but not in individuals with risk allele of this SNP (TC CC). Although there are significant relationships between SNPs or genetic risk score and change in WHR or VAI, but there is no significant interaction between FTO SNPs and DII regarding change in body mass index, WHR and VAI.

Conclusions

There may be an interactive effect between DII and the FTO rs1421085 genotypes on change in WC.

Familial resemblance and family-based heritability of nutrients intake in Iranian population: Tehran cardiometabolic genetic study

BACKGROUND

We aimed to investigate the familial resemblance of dietary intakes, including energy and nutrients, and the family-based heritability of dietary intake in different age-sex dyads of the Tehran cardiometabolic genetic study.

METHODS

This cross-sectional study was conducted on 9,798 participants, aged ≥ 18 years, with complete data in each of the third, fourth, fifth, and sixth surveys of the Tehran Cardiometabolic Genetic study, who were eligible to enter the current study based on inclusion and exclusion criteria. Nutrient intake was determined using a valid and reliable food frequency questionnaire (FFQ). FCOR command of the S.A.G.E. software was used to estimate the intra-class correlation coefficients of all relative pairs to verify the family resemblance of dietary nutrient intakes. Classical likelihood-based is used to assess the family-based heritability of dietary nutrient traits.

RESULTS

There were 4338 families with a mean family size of 3.20 ± 2.89, including 1 to 32 members (2567 constituent pedigrees and 1572 singletons) and 3627 sibships. The mean ± SD age of participants was 42.0 ± 15.2 years, and 44.5% were males. The heritability of nutrient intake ranged from 3 to 21%. The resemblance degree of energy intake and most nutrients between spouses or between parents and children is weak to moderate; however, a high resemblance of intake was observed for some food components, especially among spouses, including trans fatty acids (TFAs) (r:0.70), chromium (r:0.44), fiber(r:0.35), pantothenic acid (r:0.31), and vitamin C(r:0.31). Based on our findings, the resemblance of nutrient intake in spouses was greater than in parent-offspring. The similarity in parent-offspring nutrient intake was different, and the correlation in mother-girls nutrient intakes was greater than other parent-child correlations. Also, the lowest resemblance in nutrient intake was observed among siblings.

CONCLUSIONS

Our findings suggested a weak-to-moderate similarity between the nutrient intakes of parents and offspring. The resemblance degree in nutrient intake varied between different family pairs; the strongest correlation of nutrients was observed between spouses, which includes TFAs, chromium, fiber, pantothenic acid, and vitamin C. The lowest correlation of nutrients was between siblings, such as carbohydrates, thiamine, niacin, and vitamin K. An individual's nutrient intake can somewhat be influenced by genetics, family relationships, and the effects of parents, although the significant influence of environmental factors should not be ignored.

Dietary approach to stop hypertension and healthy eating index 2015, modify the association between FTO polymorphisms and obesity phenotypes

This study aimed to investigate the interaction of the healthy eating index (HEI) and the dietary approach to stop hypertension (DASH) diet scores with FTO polymorphisms in relation to change in obesity traits. A total of 4480 subjects aged ≥ 18 years were selected from participants of the Tehran lipid and glucose study and followed-up 3 years. Selected polymorphisms (rs1421085, rs1121980, rs8050136) were genotyped and genetic risk score (GRS) was computed. HEI and DASH scores were computed based on dietary data. Changes in body mass index (BMI), waist circumference (WC), waist to hip ratio (WHR) and visceral adiposity index (VAI) were measured. Higher adherence to both DASH and HEI scores were increased with higher ages. Individuals with high GRS had a lower change in BMI when they had higher adherence to HEI, compared to subjects with lower HEI score (P trend = 0.01). Change in WC in participants in the fourth quartile of HEI score in minor allele carriers of FTO variants was lower compared to the first quartile; conversely, higher adherence to the DASH score by this genotypic group was related to increase in WC. No significant interaction was seen between FTO polymorphisms and both diet scores regarding changes in any of obesity traits. In conclusion, in individuals with high GRS higher adherence to HEI score was associated with lower change in BMI and WC, while higher adherence to DASH diet was associated with higher change in WC, compared to individuals with lower adherence to both scores.

Evidence of familial resemblance and family-based heritability of food intakes derived from a longitudinal cohort study

We sought to investigate the familial aggregation and family-based heritability of dietary intakes among adults in a population-based longitudinal study of the Tehran Lipid and Glucose Study (TLSG). Total of 4359 males and 5439 females entered our study. We categorized foods into main groups based on the literature on main food groups and their subgroups among the Iranian dietary habits and food culture as follows: grains, fruits, vegetables, dairy, meats, legume, nuts, beverages, snacks, and fats. The intraclass correlation coefficients (ICC) are estimated to verify familial resemblance of dietary habits for all relative pairs and spouses. Family-based heritability is obtained using a mixed effect framework with likelihood-based approach. For almost all food groups, the correlation between parents and offsprings tended to be larger than those of siblings. Family-based heritability of food groups varies from the lowest 6.36% for snacks to the highest 25.67% for fruits, and 25.66% for legume. Our findings indicated weak-to-moderate similarities between parents' and offspring's food intakes; however, the similarity in parent-child food intakes was different, and the correlation in mother-daughter food intakes was stronger than other parent-child correlations, and almost all of dietary components showed strong family-based heritability.

The association between dietary acrylamide intake and the risk of type 2 diabetes incidence in the Tehran lipid and glucose study

This study aimed at investigating the association of acrylamide consumption with the incidence of type 2 diabetes (T2D) in adults. The 6022 subjects of the Tehran lipid and glucose study participants were selected. The acrylamide content of food items were summed and computed cumulatively across follow up surveys. Multivariable Cox proportional hazard regression analyses were performed to estimate the hazards ratio (HR) and 95% confidence interval (CI) of incident T2D. This study was done on men and women, respectively aged 41.5 ± 14.1 and 39.2 ± 13.0 years. The mean ± SD of dietary acrylamide intake was 57.0 ± 46.8 µg/day. Acrylamide intake was not associated with the incidence of T2D after adjusting for confounding variables. In women, a higher acrylamide intake was positively associated with T2D [HR (CI) for Q4: 1.13 (1.01-1.27), P trend: 0.03] after adjusting for confounding factors. Our results demonstrated that dietary intake of acrylamide was associated with an increased risk of T2D in women.

Diet quality and anthropometric indices of patients undergone bariatric surgery: the prospective Tehran obesity treatment study

BACKGROUND

Patients undergone bariatric surgery (BS) has long-term risks including decrease in diet quality, nutritional deficiencies and weight regain. This study focus on assessing dietary quality and food group components in patients one year after BS, the relationship between dietary quality score and anthropometric indices, and also evaluating the trend of body mass index (BMI) of these patients three years after BS.

METHODS

A total of 160 obese patients (BMI ≥ 35 kg/m²) were undergone sleeve gastrectomy (SG) (n = 108) or gastric bypass (GB) (n = 52), participated in this study. They were assessed for dietary intakes using three 24-hour dietary recalls one year after surgery. Dietary quality was assessed using food pyramid for post BS patients and healthy eating index (HEI). Anthropometric measurements were taken pre-surgery and 1, 2 and 3 years after operation.

RESULTS

The mean age of patients was 39.9 ± 11 years (79% female). The mean ± SD percentage of excess weight loss was 76.6 ± 21.0 one year after surgery. Intake patterns are generally (up to 60%) not consistent with the food pyramid. The mean total HEI score was 64 ± 12 out of 100. More than %60 of participants is exceeding the recommendations for saturated fat and sodium. The HEI score did not show significant relationship with anthropometric indices. The mean of BMI in SG group increased over three years of follow up, while in GB group, there were no significant differences in BMI during three years of follow up.

CONCLUSIONS

These findings showed that patients had not healthy pattern intake one year after BS. Diet quality did not show significant relationship with anthropometric indices. The trend of BMI three years after surgery was different based on surgery types.

Higher dietary flavonol and isoflavonoid intakes are associated with lower incidence of type 2 diabetes

Background: Adequate evidence supports beneficial effects of plant-derived phytochemicals against type 2 diabetes (T2D). Among phytochemicals, dietary flavonoids is one of the superb candidates. The whole studies are carried out in Western populations, so it is needed to investigate the risk of T2D by dietary flavonoid intakes in ethnic origins and other regions to confirm these relations. This study was conducted to investigate whether the daily consumption of total flavonoid and its subclasses can affect the incidence of type 2 diabetes (T2D) in the Iranian population. Methods: Eligible adults (n=6547) were selected from among participants of the Tehran lipid and glucose study with an average follow-up of 3.0 years. Dietary intakes were assessed using a valid and reliable 168-item semi-quantitative food frequency questionnaire. Multivariate Cox proportional hazard regression models were used to estimate the development of T2D in relation to total intake of flavonoids. Results: This study was conducted on 2882 men and 3665 women, aged 41.3±14.6 and 39.0±13.4 years, respectively. After adjustment for several potential confounders (age, sex, diabetes risk score, physical activity, energy, fiber and total fat intakes), risk of T2D decreased from tertiles 1 to 3 for flavonols (HR (95% CI): 1.00, 0.86 (0.64-1.16), 0.87 (0.63-0.93), P_trend=0.01) and isoflavonoids (HR (95% CI): 1.00, 0.84 (0.62-1.13), 0.64 (0.46-0.88), P_trend=0.02), whereas non-significant results were found for total flavonoid and other subclasses of flavonoid. Conclusion: These results emphasize the potential protective role of flavonols and isoflavonoids rich food (e.g. apple, tea, soy, and dark chocolate) in the prevention of T2D.

Diet quality indices and the risk of type 2 diabetes in the Tehran Lipid and Glucose Study

INTRODUCTION

The aim of this study was to assess the prospective association between diet quality and risk of type 2 diabetes (T2D).

RESEARCH DESIGN AND METHODS

Eligible adults (n=7268) were selected from among participants of the Tehran Lipid and Glucose Study with an average follow-up of 6.6 years. Dietary intakes were assessed using a valid and reliable semiquantitative Food Frequency Questionnaire. Anthropometrics and biochemical variables were evaluated at baseline and follow-up examinations. Dietary pattern scores were calculated for the Healthy Eating Index 2015, Mediterranean diet and the Dietary Approaches to Stop Hypertension diet. Multivariate Cox proportional hazards regression models were used to estimate the development of T2D in relation to diet quality.

RESULTS

This study was conducted on 3265 men and 4003 women aged 42.4±14.6 and 40.6±13.5 years, respectively. After adjustment for potential confounders, all three diet quality scores were not associated with risk of T2D. Among individual components of the examined dietary patterns, risk of T2D increased from quartiles 1 to 4 for sodium intake (HR (95% CI) 1.00, 0.97 (0.75 to 1.25), 1.17 (0.92 to 1.49), 1.28 (1.01 to 1.62), P_trend<0.01) and decreased from quartiles 1 to 4 for red meat intake (HR (95% CI) 1.00, 0.91 (0.72 to 1.14), 0.75 (0.58 to 0.95), 0.85 (0.67 to 1.08), P_trend<0.01).

CONCLUSION

This study emphasizes a potentially protective relationship of moderate red meat intake against development of T2D; also higher intake of sodium is related to risk of T2D.

Meat Food Group Intakes and the Risk of Type 2 Diabetes Incidence

Aim

This study aimed to evaluate the association of meats and their substitute food group intakes, including nuts, eggs, and legumes, with type 2 diabetes (T2D).

Methods

For this secondary analysis, we selected eligible adults (n = 6,112) from the Tehran Lipid and Glucose Study participants with a median follow-up of 6.63 years. Expert nutritionists assessed dietary intakes using a valid and reliable semiquantitative food frequency questionnaire. Biochemical and anthropometric variables were assessed at baseline and follow-up examinations. We used multivariable Cox proportional hazard regression models to estimate the new onset of T2D concerning meats and their substitute food groups.

Results

We performed this study on 2,749 men and 3,363 women, aged 41.4 ± 14.2 and 39.1 ± 13.1 years, respectively. The number of participants with incident T2D was 549. After adjusting for confounders, legume [HR: 1, 0.74 (0.58–0.94), 0.69 (0.54–0.90), 0.65 (0.50–0.84), P-trend = 0.01)] was inversely associated with incident T2D. Fish intake [HR: 1, 1.0 (0.79–1.27), 1.17 (0.91–1.50), 1.14 (0.89–1.45), P-trend = 0.01)] was positively associated with incident T2D. In subjects who reported poultry consumption of 36.4–72.8 g/day, a positive association [HR: 1.33 (1.03–1.71)] between poultry intake and T2D risk was observed.

Conclusion

Our findings revealed that a diet rich in legumes significantly reduced the risk of T2D incidence, while a diet high in poultry increased the risk of T2D incidence, probably due to high-temperature cooking methods and environmental contaminants.

Effective food hygiene principles and dietary intakes to reinforce the immune system for prevention of COVID-19: a systematic review

Background

This study aimed at reviewing effective food hygiene principles and dietary intakes to reinforce the immune system for prevention of corona virus disease 2019 (COVID-19).

Methods

The systematic literature search was performed in three databases from Jan. 2020 up to 10^th July 2020. English articles that focused on nutrition, food, immunity and corona virus were searched. Systematic and narrative reviews were included.

Results

After evaluation of search papers, 27 relevant articles were used in this review. The importance of nutrients, phytochemicals, probiotics and some spices were highlighted for enhancing immunity during the COVID-19 pandemic. A healthy dietary pattern with proper energy intake provides sufficient nutrients. The unhealthy dietary pattern is linked with inflammation and risk factors related to high mortality in patients with severe COVID-19 infection. Different thermal procedures have been used for the inactivation of viruses. It is recommended not to consume raw or undercooked animal products.

Conclusions

It is critical to ensure that the nutritional needs of the population are met and sustained based on standards during a COVID-19 pandemic. Clear advice on adequate calorie intake and an optimal healthy diet to support the immune function should be provided. Good hygiene practices must be performed by everyone and done in the food industry.

Evaluating machine learning-powered classification algorithms which utilize variants in the GCKR gene to predict metabolic syndrome: Tehran Cardio-metabolic Genetics Study

BACKGROUND

Metabolic syndrome (MetS) is a prevalent multifactorial disorder that can increase the risk of developing diabetes, cardiovascular diseases, and cancer. We aimed to compare different machine learning classification methods in predicting metabolic syndrome status as well as identifying influential genetic or environmental risk factors.

METHODS

This candidate gene study was conducted on 4756 eligible participants from the Tehran Cardio-metabolic Genetic study (TCGS). We compared predictive models using logistic regression (LR), Random Forest (RF), decision tree (DT), support vector machines (SVM), and discriminant analyses. Demographic and clinical features, as well as variables regarding common GCKR gene polymorphisms, were included in the models. We used a 10-repeated tenfold cross-validation to evaluate model performance.

RESULTS

50.6% of participants had MetS. MetS was significantly associated with age, gender, schooling years, BMI, physical activity, rs780094, and rs780093 (P < 0.05) as indicated by LR. RF showed the best performance overall (AUC-ROC = 0.804, AUC-PR = 0.776, and Accuracy = 0.743) and indicated BMI, physical activity, and age to be the most influential model features. According to the DT, a person with BMI < 24 and physical activity < 8.8 possesses a 4% chance for MetS. In contrast, a person with BMI ≥ 25, physical activity < 2.7, and age ≥ 33, has 77% probability of suffering from MetS.

CONCLUSION

Our findings indicated that, on average, machine learning models outperformed conventional statistical approaches for patient classification. These well-performing models may be used to develop future support systems that use a variety of data sources to identify persons at high risk of getting MetS.

The association of dietary macronutrients composition with the incidence of type 2 diabetes, using iso-energetic substitution models: Tehran Lipid and Glucose Study

AIMS

There is still controversy on optimal percentage of macronutrient intakes especially carbohydrate on prevention of type 2 diabetes (T2D). The aim of the current study was to evaluate the iso-energetic substitution of dietary macronutrients in relation to incidence of T2D.

METHODS

This prospective study was conducted on 6547 subjects who were followed for 3.0 ± 1.6 years. Dietary intakes were evaluated using a valid and reliable semi-quantitative food frequency questionnaire. Biochemical variables and anthropometrics were evaluated at baseline and follow-up examinations. Multivariate Cox proportional hazard regression models were used to estimate the hazards ratio (HR) of T2D.

RESULTS

A one unit higher proportion of carbohydrate from whole grain at the expense of carbohydrate from non-whole grain (HR = 0.82, 95% CI = 0.71-0.95), protein (HR = 0.75, 95% CI = 0.60-0.94), total fat (HR = 0.79, 95% CI = 0.67-0.93), saturated fatty acid (HR = 0.79, 95% CI = 0.65-0.96), poly-unsaturated fatty acid (HR = 0.81, 95% CI = 0.68-0.96) and mono-unsaturated fatty acid (HR = 0.75, 95% CI = 0.60-0.94) was associated with decreased risk of T2D. The substitution of protein and fats was not associated with diabetes. Risk of T2D increased from quartiles 1-4 for trans-fatty acid (HR: 1.00, 1.27, 0.95, 1.97, P_trend = 0.01).

CONCLUSIONS

A higher proportion of carbohydrate from whole grain in replacement of refined grain, and other macronutrients was associated with decreased risk of T2D. Also our study suggests a positive association between trans-fatty acid intake and risk of T2D.

The resemblance of dietary intakes in three generations of parent-offspring pairs: Tehran lipid and glucose study

The degree of similarity between dietary intakes of offspring and their parents may be different across various countries. This study aimed to investigate the correlation between food group intakes and dietary quality in three younger-middle-older generations by living arrangements. Individuals who participated in the 5th survey of the Tehran Lipid and Glucose Study, 1286 families (4685 subjects) with complete data for two or three generations were entered in this cross-sectional study. Genetic data management system from Progeny Software was used to error-check family data pedigree details. Dietary data were gathered using a valid and reliable food frequency questionnaire. The healthy eating index score was computed. Data of parents with their offspring were compared using paired t-test and partial correlation. The mean ages of grandfathers and grandmothers were 69.4 ± 7.9 and 63.7 ± 8.5 respectively. Of girls and boys who lived with their parents, about 59% were 20 years or older. The correlation of parents' dietary intake and their young offspring who lived with them was higher than that of parents and adult offspring who lived independently from their parents. The correlation of dietary quality and food group intakes in mother-offspring dyads (mother-son: 0.37, mother-daughter: 0.44) were higher than father-offspring (father-son: 0.34, father-daughter: 0.25) dyads. The dietary quality of parents was higher than that of offspring in both living statuses. The dietary intake of adult married offspring was not correlated with their parents; also there was no correlation between the dietary quality of younger and older generations. There were weak to moderate similarities between food group intakes of parent-offspring dyads that lived with their parents.

Using Machine Learning Techniques to Predict Factors Contributing to the Incidence of Metabolic Syndrome in Tehran: Cohort Study

Background

Metabolic syndrome (MetS), a major contributor to cardiovascular disease and diabetes, is considered to be among the most common public health problems worldwide.

Objective

We aimed to identify and rank the most important nutritional and nonnutritional factors contributing to the development of MetS using a data-mining method.

Methods

This prospective study was performed on 3048 adults (aged ≥20 years) who participated in the fifth follow-up examination of the Tehran Lipid and Glucose Study, who were followed for 3 years. MetS was defined according to the modified definition of the National Cholesterol Education Program/Adult Treatment Panel III. The importance of variables was obtained by the training set using the random forest model for determining factors with the greatest contribution to developing MetS.

Results

Among the 3048 participants, 701 (22.9%) developed MetS during the study period. The mean age of the participants was 44.3 years (SD 11.8). The total incidence rate of MetS was 229.9 (95% CI 278.6-322.9) per 1000 person-years and the mean follow-up time was 40.5 months (SD 7.3). The incidence of MetS was significantly (P<.001) higher in men than in women (27% vs 20%). Those affected by MetS were older, married, had diabetes, with lower levels of education, and had a higher BMI (P<.001). The percentage of hospitalized patients was higher among those with MetS than among healthy people, although this difference was only statistically significant in women (P=.02). Based on the variable importance and multiple logistic regression analyses, the most important determinants of MetS were identified as history of diabetes (odds ratio [OR] 6.3, 95% CI 3.9-10.2, P<.001), BMI (OR 1.2, 95% CI 1.0-1.2, P<.001), age (OR 1.0, 95% CI 1.0-1.03, P<.001), female gender (OR 0.5, 95% CI 0.38-0.63, P<.001), and dietary monounsaturated fatty acid (OR 0.97, 95% CI 0.94-0.99, P=.04).

Conclusions

Based on our findings, the incidence rate of MetS was significantly higher in men than in women in Tehran. The most important determinants of MetS were history of diabetes, high BMI, older age, male gender, and low dietary monounsaturated fatty acid intake.

Nutrient Intake and Deficiency of Patients 1 Year After Bariatric Surgery: Tehran Obesity Treatment Study (TOTS)

PURPOSE

This study aimed at assessing nutrient adequacy after 1 year in patients who had undergone gastric bypass (GB) surgery or sleeve gastrectomy (SG) and to investigate the association of nutrient adequacy with anthropometric indices.

METHODS

A total of 180 severely obese patients (BMI ≥ 35 kg/m²) were selected among the participants of Tehran Obesity Treatment Study. Nutritional assessments were performed over 3 days of 24-h dietary recall. To evaluate the nutrient adequacy ratio (NAR), the subject's nutrient intake was divided by the dietary reference intakes. The mean adequacy ratio (MAR) was also determined as the sum of NARs divided by the number of involved nutrients (n = 11).

RESULTS

The mean age of SG (67%) and GB (32%) patients was 39.2 ± 12 and 41.4 ± 10 years, respectively. SG patients had more postoperative fat-free mass (52.0 ± 12 kg) than GB patients (49.7 ± 8 kg) (P < 0.05). The most common postoperative serum nutrient deficiencies were related to vitamin B12 (30%), ferritin (19%), and 25-hydroxyvitamin D (16.2%). Moreover, high inadequacy of protein (> 80%) and total fat (> 70%) intake was reported. The MAR score showed that almost 45% of the patients had possibly adequate intakes of some nutrients. The adequacy of nutrients was positively associated with fat-free mass (β = 8.67, P < 0.05).

CONCLUSION

These findings revealed that patients had inadequate nutrient intakes 1 year after bariatric surgery, which was accompanied by serum nutritional deficiencies. Compared to GB patients, SG patients had a better body composition. Overall, compliance of patients with dietary guidelines and supplementations needs to be carefully monitored in the postoperative period.

Dietary diversity modifies the association between FTO polymorphisms and obesity phenotypes

The current study aimed to evaluate the interaction of the dietary diversity score (DDS) and FTO polymorphisms concerning obesity phenotypes. The 4480 subjects of this cohort study were selected. The polymorphisms rs1121980, rs14211085 and rs8050136 were selected and genotyped. The weighted method was used to calculate the genetic risk score (GRS). Obesity marker changes were calculated. Those with minor allele carriers of rs1121980 had lower body mass index changes (Q1: 1.58 ± 0.60 vs. Q4: 0.13 ± 0.59) and visceral adiposity index (VAI) (Q1: -0.00 ± 0.02 vs. Q4: -0.04 ± 0.02) when they had higher DDS (P interaction = 0.05). Carriers of the minor allele of rs8050136 had significant VAI change across DDS quartiles (Q1: -0.01 ± 0.02 vs. Q4: -0.02 ± 0.02, P interaction = 0.05). No significant interaction was found between the GRS and DDS on general obesity. The pattern of dietary diversity may have a mediatory role in improving obesity markers in subjects with a more genetic predisposition to adiposity.

A nutrient pattern characterized by vitamin A, C, B6, potassium, and fructose is associated with reduced risk of insulin-related disorders: A prospective study among participants of Tehran lipid and glucose study

BACKGROUND

Insulin-related disorders, including insulin resistance, insulin insensitivity, and insulinemia, is considered early predictors of major chronic disease risk. Using a set of correlated nutrient as nutrient patterns to explore the diet-disease relationship has drawn more attention recently. We aimed to investigate the association of nutrient patterns and insulin markers' changes prospectively among adults who participated in the Tehran Lipid and Glucose Study (TLGS).

METHODS

For the present study, 995 men and women aged 30-75 years, with complete information on insulin and dietary intake in survey III TLGS, were selected and followed three years until survey IV. Dietary intakes at baseline were assessed using a valid and reliable food frequency questionnaire (FFQ). Nutrient patterns were derived using principal component analysis (PCA). We extracted five dominant patterns based on the scree plot and categorized them into quartiles. Linear regression analysis was conducted to investigate the association between Nutrient patterns and three-year insulin markers changes, including fasting insulin, HOMA-IR, and HOMA-S.

RESULTS

The mean (SD) age and BMI of participants (43.1 % male) were 46.2(10.9) year and 28.0(4.7) kg/m², respectively. The median (IQR, 25, 75) of 3 years changes of insulin, HOMA-IR and HOMA-S were 0.35 (- 1.71, 2.67) mU/mL, 0.25 (- 0.28, 0.84) and - 6.60 (- 22.8, 7.76), respectively. In the fully adjusted model for potential confounders, per each quartile increment of the fifth nutrient pattern, the β coefficients (95 % CI) of changes in insulin, HOMA-IR, and HOMA-S were - 0.36 (- 0.62, - 0.10); P value = 0.007, -0.10 (-0.19, -0.01); P value = 0.022, and 1.92 (0.18, 3.66); P value = 0.030, respectively. There were no significant association between other nutrient patterns and insulin related indices.

CONCLUSIONS

Present study showed that high adherence to a nutrient pattern rich in vitamin A, vitamin C, pyridoxine, potassium, and fructose is inversely associated with 3-years changes in insulin, HOMA-IR, and directly associated with HOMA-S.

The association of priori and posteriori dietary patterns with the risk of incident hypertension: Tehran Lipid and Glucose Study

Background

The aim of this study was to investigate the association of dietary patterns with incident hypertension.

Materials/methods

This prospective study was conducted on 4793 individuals of Tehran lipid and glucose study participants, aged ≥ 18 years who were followed for a median of 6.3 years from 2008–2011 to 2016–2018. A valid and reliable semi-quantitative food frequency questionnaire was used to assess usual dietary intakes. Anthropometrics and blood pressure were assessed at baseline and during follow up examinations. Dietary patterns were derived using principal component analysis (PCA). Healthy eating index (HEI) and dietary approach to stop hypertension (DASH) score were measured based on dietary recommendations. Time-dependent Cox models adjusting for confounders were used to examine the association between dietary patterns and the risk of hypertension.

Results

During follow-up, a total of 727 incident cases of hypertension were identified. The mean ± SD age at baseline was 40.3 ± 13.5 and 37.9 ± 12.1 years in men and women, respectively. Two dietary patterns (the healthy and unhealthy) were extracted by PCA. Compared with participants in the first quartile, a 23% (HR: 1.23; 95%CI 1.00–1.53; P trend: 0.056) increased risk of hypertension was found in the fourth quartile of HEI score. This association was disappeared after further adjustment for confounders. Increasing DASH score, the healthy and unhealthy dietary pattern were not associated with risk of hypertension.

Conclusion

Our findings showed that higher adherences to the posteriori- and priori-dietary patterns were not associated with risk of hypertension in this population.

The association of dietary macronutrients composition with the incidence of cardiovascular disease, using iso-energetic substitution models: Tehran lipid and glucose study

BACKGROUND AND AIMS

Dietary macronutrient composition plays an important role in the prevention of cardiovascular disease (CVD). This study aimed at assessing the iso-energetic substitution of dietary macronutrients in relation to the incidence of CVD.

MATERIALS AND RESULTS

This prospective study was conducted on 5102 individuals of Tehran lipid and glucose study participants, aged 20-70 years who were followed for 5.3 years. A valid and reliable semi-quantitative food frequency questionnaire was used to assess dietary intakes. The hazard ratio of CVD for each 5% of energy from macronutrients at the expense of another macronutrient was calculated using the substitution model. During follow-up, a total of 206 CVD outcomes were identified. Mean age of participants (44.2% men) was 47.0 ± 12 and 45.6 ± 11 for men and women, respectively. Substituting 5% of energy from all types of macronutrients by 5% percentage of energy from combined saturated fatty acids (SFA) and monounsaturated fatty acids (MUFA) was associated with a decrease in the risk of CVD by almost 20%. Higher energy intake from total-, starchy-, and nonstarchy carbohydrates replaced by other macronutrients was not significantly associated with the risk of CVD. Each 5% of energy from animal protein (HR: 1.09 and CI: 1.02-1.16) independently increased the risk of CVD in the adjusted Cox proportional hazard regression analyses.

CONCLUSION

Higher percentage of energy from animal protein independently increased the risk of CVD, replacement of SFA and MUFA together with other macronutrients was inversely associated with CVD risk.

Dietary macro- and micro-nutrients intake adequacy at 6th and 12th month post-bariatric surgery

BACKGROUND

Bariatric surgery (BS) is considered as an effective solution to control morbid obesity. Food restrictions resulting from the operation may decrease dietary nutrient intakes, particularly during the first year after BS. This study mainly aimed to assess the adequacy of dietary nutrient intakes at 6th and 12th month after BS.

METHOD

Of the severely obese participants in the Tehran obesity treatment study in 2015-2016, 58 patients undergoing Roux-En-Y gastric bypass (N = 16) or sleeve gastrectomy (N = 42) were selected from Tehran Obesity Treatment Center. To assess the patients' dietary intake, a three-day, 24-h dietary recall was obtained on three unscheduled days (two non-consecutive weekdays and one weekend day) at 6th and 12th month after BS. To evaluate the adequacy of nutrient intake, the patients' intakes were compared to the current dietary reference intakes (DRIs), including estimated average requirements (EAR) or Adequate Intakes (AI).

RESULTS

The mean age of the participants (71% women) undergoing BS was 37 ± 8 years. Anthropometric parameters significantly decreased at the 12th month after BS. The percentage of energy from carbohydrate intake increased significantly between the 6th and 12th month after BS (P = 0.04). The mean ± SD of protein intake was lower than the recommended dosage with a dramatic decrease from 45 ± 30 to 31 ± 15 (g/day) between the two intervals (P = 0.001). The mean intake of saturated fatty acid (SFA) decreased dramatically (P < 0.001) from 6 to 12 month; however, the median intake of n3-polyunsaturated fatty acid (n3-PUFA) intake increased (P = 0.02). None of the participants showed nutrient intake adequacy in terms of biotin, fat soluble vitamins, pantothenic acid, potassium, and zinc. Moreover, less than 10% of the participants showed nutrient intake adequacy in terms of folate, magnesium, manganese, and calcium according to DRIs during the both intervals after BS.

CONCLUSION

Bariatric surgery can reduce dietary intakes, which is more obvious 12 months after the surgery. Out of 21 micronutrients, nearly all could not met the EAR and were received < 50%, also had significant reduction from the 6th to12th month after surgery.

Acrylamide content of collected food products from Tehran's market: a risk assessment study

Acrylamide concentration in food products collected from the Tehran market was investigated by the aid of a dispersive liquid-liquid microextraction (DLLME) system coupled with gas chromatography-mass spectrometry (GC-MS). Also, the dietary exposure distribution and related potential risk for acrylamide ingestion were estimated by the Monte Carlo simulation (MCS). The highest and lowest mean concentration of acrylamide was detected in coffee and roasted nuts samples as 549 and 133 μg/kg, respectively. The mean acrylamide dietary exposure values for children (3-10 years), adolescents (11-17 years), adults (18-60 years), and seniors (61-96 years) were estimated to be 1.81, 1.02, 0.61, and 0.53 μg/kg body weight (BW)/day, respectively. In all age groups, except children, the estimated exposure in men and boys was higher than that in women and girls. Bread, despite containing low acrylamide content groups (157 μg/kg while compared with other, except roasted nuts), showed with the highest contribution rate in all age groups due to its high consumption rate. The estimated incremental lifetime cancer risk (ILCR) for all age groups was noted as greater than 10^-4 indicating serious risk to the population. Moreover, the margin of exposure (MOE) values based on carcinogenicity showed health concern to all age groups (< 10,000). Regarding the non-carcinogenic risk, the target hazard quotient (THQ) was lower than 1, and MOE based on neurotoxicity was higher than 125 (safety thresholds), which represented negligible and ignorable risk in all age groups except in a small group of children and adolescents. Graphical abstract.

The interaction between dietary patterns and melanocortin-4 receptor polymorphisms in relation to obesity phenotypes

INTRODUCTION

Data shows that interactions between dietary factors and genetic variants can modulate the association of polymorphisms such as the Melanocortin-4 receptor (MC4R) gene with obesity. Considering the limited data available on this topic we aimed to investigate interactions between dietary patterns (DPs) and MC4R polymorphisms in relation to obesity phenotypes.

METHODS

This cohort study was performed in the framework of Tehran Lipid and Glucose Study; for eligible participants in this study (n=3850), the median follow-up was 4 years. DPs were determined using factor analysis. The genotypes of polymorphisms (17782313rs and 12970134rs) were identified and their interaction with DPs were assessed in relation to incidence of obesity phenotypes including central obesity, general obesity and visceral adiposity dysfunction.

RESULTS

The mean age of participants (62.5% females) were 37.0±13.7 years. Two main DPs (healthy and unhealthy) were extracted. C-allele carriers of rs17782313 in higher quartiles of the healthy DP score had a significant decrease in the incidence of general obesity, compared to those who had the TT genotype (HR=0.61, 95% CI=0.42-0.89, P interaction=0.01). For rs12970134 A-allele carriers, subjects in the second compared to the first quartile of the healthy DP score, had a significant decrease in the incidence of general obesity (HR=0.68, 95% CI=0.46-0.99). There were no significant interaction between DPs and MC4R variants in relation to other obesity phenotypes.

CONCLUSION

Our results indicate that the healthy DP could interact with rs17782313 in relation to incidence of general obesity.

Nutrient patterns and cardiometabolic risk factors among Iranian adults: Tehran lipid and glucose study

Background

The present study aimed to assess the relation between nutrient patterns and changes in adult anthropometric and cardiometabolic factors.

Methods

This study was conducted on 1637 adults participating in the Tehran Lipid and Glucose Study (2005–2008), who were free of cardiovascular diseases and cancer and had completed dietary data. They were followed to the next survey (2008–2011). Dietary intakes were collected and nutrient patterns were obtained. Three year changes in anthropometric and cardiometabolic factors were measured.

Results

Five nutrient patterns were extracted. The first pattern was characterized by “plant protein, thiamine, niacin, and minerals including phosphorus, zinc, copper, magnesium, manganese, and selenium”. Animal protein, lactose, vitamin D, riboflavine, pantothenic acid, vitamin B12, calcium, phosphorus, and zinc" were loaded in the second pattern. The third and fourth patterns were characterized by “vitamin K, fiber, calcium, iron, manganese, and potassium”, and “high correlation with starch, thiamine and folate, and negative correlation with mono and poly unsaturated fatty acids and vitamin E”, respectively. The fifth pattern was high in Fructose, vitamins A, C, pyridoxine, and potassium. There was no association between nutrient patterns and 3-year changes in blood pressure and fasting blood glucose; whereas, per each quartile increment of the fifth pattern adjusted for potential confounders, triglyceride change was decreased [β = − 3.66, 95% CI (− 6.57, − 0.57); P for trend = 0.014].

Conclusion

Present study indicates that nutrient patterns may have an association with cardiometabolic factors, particularly a pattern rich in fructose, vitamins A, C, pyridoxine, and potassium which decreases triglyceride level.

The Association of Dietary Polyphenol Intake with the Risk of Type 2 Diabetes: Tehran Lipid and Glucose Study

PURPOSE

The current study aimed to investigate the relationship between daily consumption of total polyphenol and its subclasses and the incidence of diabetes.

MATERIALS AND METHODS

Eligible adults (n=6,547) were chosen from among participants of the Tehran Lipid and Glucose Study (TLGS) with an average follow-up of 3.0±1.6 years. Dietary intakes were evaluated using a valid and reliable semi-quantitative food frequency questionnaire. Biochemical variables and anthropometrics were evaluated at baseline and follow-up examinations. Multivariate Cox proportional hazard regression models were used to estimate the development of type 2 diabetes mellitus (T2DM) in relation to total intake of polyphenol and its subclasses (flavonoids, phenolic acids, stilbenes, and lignans).

RESULTS

This study was conducted on 2,882 men and 3,665 women, aged 41.3±14.6 and 39.0±13.4 years, respectively. The number of participants with the new-onset T2DM was 253. Mean intake of total polyphenol was 346±245 mg/1000 kcal. Risk of type 2 diabetes decreased from quartiles 1 to 4 for total polyphenols (HR: 1.00, 0.37, 0.61, 0.50, P _trend<0.01), phenolic acids (HR: 1.00, 0.57, 0.49, 0.45, P _trend<0.01), and lignans (HR: 1.00, 0.67, 0.61, 0.60, P _trend<0.01), whereas non-significant results were found for flavonoids and stilbenes. This study suggests an inverse association between total intake of polyphenols, phenolic acids, and lignin, and the risk of T2DM.

CONCLUSION

These results emphasize the potential protective role of polyphenol rich food groups (especially fruits and vegetables) in the prevention of T2DM.

The association of dietary macronutrients with anthropometric changes, using iso-energetic substitution models: Tehran lipid and glucose study

Background

The consequences of optimal dietary macronutrient compositions especially quality of proteins on weight gain still remain controversial. The aim of the current study was to evaluate the iso-energetic substitution of dietary macronutrients in relation to anthropometric changes.

Methods

This prospective study was conducted on 2999 men and 4001 women aged 20–70 years who were followed for 3.6 years. A valid and reliable 168-item semi-quantitative food frequency questionnaire was used to assess usual dietary intakes. Weight (kg) and waist circumference (WC) (cm) changes were calculated by subtracting the weight and WC at baseline from their measurements at follow up. Participants were divided into two groups; those with no change or decrease in weight or WC and those with increase in weight or WC. Dietary macronutrients (percentage of energy) divided by 5 to calculate one unit.

Results

A one unit higher proportion of carbohydrates at the expense of all types of fatty acids was associated with weight loss in men (P < 0.05). A one unit higher proportion of plant proteins at the expense of animal protein (β = − 0.84), non-starch carbohydrates (β = − 0.86), saturated fat (β = − 0.76), mono-unsaturated fat (β = − 0.76) and poly-unsaturated fat (β = − 0.86) was associated with weight loss (P < 0.05). A one unit higher proportion of plant proteins at the expense of animal proteins (OR: 0.49), non-starch carbohydrates (OR: 0.49), saturated fat (OR: 0.49), mono-unsaturated fat (OR: 0.49), and poly-unsaturated fat (OR: 0.48) was associated with a lower risk of increase in WC (P < 0.05).

Conclusions

A higher proportion of dietary plant protein in replacement of simple carbohydrates, fats and animal proteins was associated with a lower increase in weight or WC.

The association of dietary patterns and adherence to WHO healthy diet with metabolic syndrome in children and adolescents: Tehran lipid and glucose study

BACKGROUND

The optimal dietary pattern for reducing the extent of metabolic syndrome (MetS) has not been well established yet. The aim of this study was to evaluate dietary patterns and adherence to WHO healthy diet in children and adolescents and their associations with MetS.

METHODS

Subjects of this cohort study were selected from among children and adolescents of the Tehran Lipid and Glucose Study participants, aged 6-18 years (n = 424). Dietary measurements were collected using a valid and reliable food frequency questionnaire. MetS was defined as the existence of at least 3 risk factors according to the Cook criteria. Diet was assessed based on dietary components of the WHO healthy diet. Dietary patterns were defined by principal component analysis.

RESULTS

The mean ± SD age of participants (42% boys and 57% girls) was 13.5 ± 3.7 years. The most consistency with the WHO healthy diet was observed for cholesterol, free sugar and protein consumption in both genders, and the least was for n-3 poly-unsaturated fatty acid, trans-fatty acid and salt. Intake of SFA up to 12% of energy intake (third quartile) reduced the risk of MetS, compared to the first quartile. Subjects in the third quartile of n-6 poly-unsaturated fatty acid intake (6.2% of energy) showed the lowest odds ratio of MetS compared to the first quartile (OR: 0.18, CI: 0.04-0.66). In the adjusted model, the risk of MetS reduced across quartiles of MUFA intake by 60% (OR: 1, 0.40, 0.40, 0.42; P trend = 0.05). No significant trends were observed in the risk of MetS components across quartiles of the WHO healthy diet components. Three major dietary patterns were identified, the healthy, unhealthy and cereal/meat. An increased risk of MetS was observed in the highest quartile of unhealthy dietary pattern score compared to the lowest quartile (OR: 1, 0.81, 0.93, 2.49; P trend = 0.03).

CONCLUSIONS

Our results demonstrated that the majority of our population did not meet some components of WHO healthy diet recommendations. The quality and quantity of fatty acid intakes were associated with risk of MetS. Adherence to unhealthy dietary pattern was associated with two-fold increase in MetS risk.

Red meat and dietary iron intakes are associated with some components of metabolic syndrome: Tehran Lipid and Glucose Study

BACKGROUND

This study was conducted to investigate whether the daily consumption of haem, non-haem, total iron and red meat can affect the occurrence of metabolic syndrome (MetS) and its components.

METHODS

Eligible adults (n = 4654) were selected from among participants of the Tehran Lipid and Glucose Study with an average follow-up of 3.8 years. Dietary intakes were assessed using a valid and reliable semi-quantitative food frequency questionnaire. Anthropometrics and biochemical variables were evaluated at baseline and follow-up examinations. The occurrence of MetS and its components were assessed in relation to haem, non-haem, total iron and red meat intakes.

RESULTS

There was no relationship between different types of dietary iron and red meat intakes and the incidence of MetS in the Tehranian population. Risk of hypertension decreased from quartiles 1 to 4 for haem iron (HR: 1.00, 0.92, 0.81, 0.80, P_trend < 0.01) and red meat intake (HR: 1.00, 0.89, 0.84, 0.77, P_trend < 0.01). The association between hyperglycemia and the fourth quartile of total iron intake was significant (HR = 1.98, 95% CI 1.08-3.63); and the risk of high triglyceride appeared to increase in higher quartiles of total iron intake (HR: 1.00, 1.17, 1.49, 1.75, P_trend = 0.01) compared to lower quartiles.

CONCLUSION

Our study suggests a potentially protective relationship of haem and moderate red meat intake against development of high blood pressure; and higher intake of total iron is related to hyperglycemia and high triglyceride.

Evaluating the interaction of common FTO genetic variants, added sugar, and trans-fatty acid intakes in altering obesity phenotypes

BACKGROUND AND AIMS

The results of studies on the effect of trans-fatty acids (TFAs) and added sugars on obesity are not consistent. This study aimed to investigate whether the association of changes in general and central obesity with added sugar and TFA intakes is modified by common fat mass and obesity-associated gene (FTO) polymorphisms, in isolation or in a combined-form genetic risk score (GRS).

METHODS AND RESULTS

Subjects of this cohort study were selected from among adult participants of the Tehran Lipid and Glucose Study (n = 4292, 43.2% male). Dietary data were collected using a valid and reliable food frequency questionnaire. The genotypes of selected polymorphisms (rs1421085, rs1121980, and rs8050136) were determined. Genetic risk score (GRS) was calculated using the dominant weighted method. The mean age of participants was 42.6 ± 14 and 40.4 ± 13 years in men and women, respectively. FTO rs8050136 polymorphisms and TFAs have a significant interaction in changing body mass index (BMI) (P interaction = 0.01). There were no changes in waist circumference (WC) and BMI among FTO risk allele carriers, across quartiles of added sugar intake. GRS and TFA intakes significantly interacted in altering the BMI and WC; thus, a higher intake of TFAs was associated with higher changes of BMI and WC in subjects with high GRS (P trend<0.05) compared to individuals with low GRS.

CONCLUSION

Our findings suggest that TFA intake can increase the genetic susceptibility of FTO SNPs to BMI or WC change.

Long-Term Effectiveness of a Lifestyle Intervention: A Pragmatic Community Trial to Prevent Metabolic Syndrome

INTRODUCTION

The purpose of this study is to evaluate the long-term effectiveness of a community-based lifestyle education on primary prevention of metabolic syndrome in a middle-income country.

STUDY DESIGN

This study followed 3,180 individuals free of metabolic syndrome who were under the coverage of three health centers in Tehran from 1999 until 2015. They were undergoing triennial examinations resulting in four re-exams. People in one of three areas received interventions consisting of family-, school-, and community-based educational programs, including a face-to-face educational session at baseline. Data were analyzed considering the incidence of metabolic syndrome at each re-exam and also repeated-measure analysis including all re-exams together. Weighting was considered to correct selection bias because of loss to follow-up. Data were analyzed in 2017.

RESULTS

After 3 years, 149 of 852 participants in the intervention and 471 of 2,328 people in control area developed metabolic syndrome at first re-exam resulting in a RR of 0.78 (95% CI=0.67, 0.92). The difference between groups remained unchanged up to the 6-year follow-up (RR=0.79, 95% CI=0.66, 0.93, at second re-exam), but disappeared during the third and fourth re-exams (RR=1.04, 95% CI=0.91, 1.18 and RR=1.03, 95% CI=0.91, 1.16, respectively). Marginal models for longitudinal data showed a significant interaction between intervention and time of re-exams. Further analyses showed that the effect of the intervention might have been rooted in improvement of lipid profile and glucose level.

CONCLUSIONS

In a middle-income country, face-to-face educational sessions followed by a long-term maintenance community-level educational program could reduce the risk of metabolic syndrome for up to 6 years. A booster face-to-face session is recommended to retain this preventive effect.

TRIAL REGISTRATION

This study is registered at Iran Registry for Clinical Trials (http://irct.ir) IRCT138705301058N1.

Empirical dietary inflammatory pattern and risk of metabolic syndrome and its components: Tehran Lipid and Glucose Study

BACKGROUND

The rising incidence of metabolic syndrome (MetS) is a major public health problem. The inflammatory potential of diet contributes to the development of MetS. The aim of this study was to investigate the relationship between empirical dietary inflammatory pattern (EDIP) and risk of MetS among the Tehranian population. Our hypothesis was that high EDIP would increase the risk of MetS and its components.

METHODS

In this prospective study, 2216 adults were selected from among the Tehran Lipid and Glucose Study participants. The usual dietary intakes were estimated using a valid and reliable food frequency questionnaire. Biochemical and anthropometric measurements were assessed at baseline and over 6.2 years of follow up. MetS components were defined according to the modified national Cholesterol Education Program Adult Treatment Panel III. The inflammatory potential of diet was calculated using EDIP score; more positive scores means higher pro-inflammatory diet. Adjusted logistic regression models were used to estimate the occurrence of MetS and its components across quartiles of EDIP score.

RESULTS

Mean ± SD for EDIP score was 0.61 ± 0.40 (range - 2.3 to 6.9). Participants with the highest EDIP scores, had a higher risk of MetS incidence compared to those with the lowest score (OR: 1.75, 95% CI 1.21-2.54, P_trend = 0.003). Among the MetS components, hyperglycemia, abdominal obesity, and low HDL-C had a significant positive association with EDIP score; (OR: 1.46, 95% CI 1.03-2.08, P_trend = 0.026), (OR: 1.43, 95% CI 1.03-1.97, P_trend = 0.046), and (OR: 1.57, 95% CI 1.34-2.19, P_trend = 0.015), respectively. No significant association was found between EDIP score, hypertension and hypertriglyceridemia.

CONCLUSION

Our finding indicated that higher intake of the pro-inflammatory diet may be an independent risk factor for the development of MetS, hyperglycemia, low HDL-C and abdominal obesity in Tehranian adults.

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 CVD in our population was western DP. Patterns of amino acid intakes may contribute 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 ≤ 12 years was significantly higher in girls with higher intakes of milk, calcium, magnesium, and phosphorous. Among children and adolescents, higher adherence to the dietary approaches to stop hypertension (DASH)-style diet decreased the risk of abdominal obesity, whereas increased adherence to the western DP could contribute to general and abdominal obesity. A three-year follow-up of adult participants showed that higher intakes of phytochemical-rich foods were inversely related to development of insulin resistance. Higher adherence to the healthy DPs was associated with the reduced risk of hyperlipidemia and hypertention. Nutrition interventions postponed rise in the prevalence of MetS. The DASH diet resulted in weight reduction compared to control diet.

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.

Cholesteryl ester transfer protein gene variations and macronutrient intakes interaction in relation to metabolic syndrome: Tehran lipid and glucose study

Objective(s):

There are controversial results regarding the effect of the interaction of CETP polymorphisms with dietary fats on the lipid profiles. The aim of this study was to examine the effect of CETP polymorphisms (rs5882 and rs3764261) and macronutrient intakes interaction in relation to metabolic syndrome (MetS) or its components.

Materials and Methods:

In this nested case-control study, subjects were selected from among participants of the Tehran Lipid and Glucose Study. Cases (n=441) were individually matched with two controls (844 non-MetS subjects). DNA samples were genotyped with HumanOmniExpress-24-v1-0 bead chips, including 649,932 SNP loci.

Results:

The mean ages at baseline were 38.1±10 and 37.0±10 years in women and 36.2±11 and 36.3±11 years in men, respectively in cases and controls. We did not find significant gene-diet interactions between rs5882 and dietary macronutrient intakes in relation to MetS risk. The risk of low HDL-C was lower in the first quartile of MUFA and total fat intake in G allele carriers, compared to AA genotype group. The risk of high BP appeared to increase significantly in higher quartiles of trans-fatty acid intakes (>1.81% of total energy intake) in G allele carriers compared with the AA genotype group. No significant interactions were found between rs3764261 and macronutrient intakes in association with MetS or its components.

Conclusion:

Our findings demonstrate that dietary fats modify the association of rs5882 and risk of low HDL-C and high blood pressure.

The Effects of a Community-Based Lifestyle Intervention on Metabolic Syndrome and Its Components in Adolescents: Findings of a Decade Follow-Up

BACKGROUND

The increasing prevalence of metabolic syndrome (MetS) in childhood makes lifestyle interventions imperative during adolescence. This study aimed to assess the effects of a community-based lifestyle intervention on MetS and its components in adolescents.

METHODS

Adolescents, based on their residential area were categorized into three groups: complete intervention (residing in the intervention area at baseline and during all follow-ups), incomplete intervention (residing in either the intervention or control areas and were in transition between these two areas), and control group (residing in the control area at baseline and throughout all follow-ups). All measurements were repeated every 3 years for up to 9 years. Lifestyle intervention aimed at achieving healthy dietary patterns and increasing physical activity. Generalized estimating equation models were used to analyze data.

RESULTS

In boys with incomplete intervention versus controls, the prevalence of MetS was significantly lower in the short term (14.0 vs. 22.9), but not in long term. In boys with complete intervention, the prevalence was significantly lower versus controls (9.0 vs. 23.4) in the long term. In girls, the short-term prevalence of MetS was significantly lower in the complete intervention group compared with controls (2.5 vs. 9.1) and then remained constantly low in all study groups after that. Among MetS components, in boys, triglycerides and fasting plasma glucose in the short term and high-density lipoprotein mid term, and in girls HDL in mid and long term were both significantly improved. The odds of MetS decreased significantly in the complete [odds ratio (OR): 0.516, confidence interval (95% CI): 0.273-0.973] and incomplete (OR: 0.591, 95% CI: 0.358-0.976) intervention groups only in boys. The short- and long-term interventions resulted improvement in some of the MetS components in both genders.

CONCLUSIONS

The healthy lifestyle intervention reduced the risk of MetS in both genders in short and long term, but with different patterns and improved some of the MetS components.

The Association Between Empirical Dietary Inflammatory Pattern and Metabolic Phenotypes in Overweight/Obese Adults

OBJECTIVES

The study aimed to investigate whether diet-induced inflammation assessed by Empirical Dietary Inflammatory Pattern (EDIP) is associated with odds of unhealthy metabolic phenotype and components of metabolic syndrome (MetS).

METHODS

This cross-sectional study included 403 overweight/obese individuals recruited from employees of two pharmaceutical companies in Iran. The weighted intake of 15 food groups was summed to construct EDIP and metabolic phenotypes were defined based on MetS criteria.

RESULTS

After adjusting for age, sex, BMI, and marital status, the odds of unhealthy phenotype increased significantly from quartile 1 to quartile 4 (P-trend = 0.013). However, the association became non-significant after adjusting for energy intake. Compared to those in the lowest quartile, individuals with higher EDIP scores had higher odds of high fasting blood sugar (FBS) (P-trend = 0.031) and low HDL-C (P-trend = 0.036) after adjusting for all covariates. By adding energy intake into the model, an inverse association was observed between EDIP, waist circumference (WC), and odds of high WC.

CONCLUSIONS

A higher pro-inflammatory diet was associated with higher odds of unhealthy phenotype, high FBS, and low-HDL-C in overweight/obese individuals. However, the association with unhealthy phenotype seems to be dependent on the energy intake.

Food Patterns and Framingham Risk Score in Iranian Adults: Tehran Lipid and Glucose Study: 2005-2011

BACKGROUND

Healthy dietary habits can prevent cardiovascular diseases (CVD). The aim of this study was to investigate the association between dietary patterns and predicted risk of CVD development using Framingham Risk Score (FRS) in Iranian population over 6 years of follow-up.

METHODS

In this prospective study, 2333 individuals aged 30-74 years with a 10-year predicted risk <10% and without a CVD diagnosis at baseline were recruited from participants in the third survey of Tehran Lipid and Glucose Study. Usual dietary intake was assessed using a validated semiquantitative food frequency questionnaire. Dietary patterns were identified using factor analysis. The risk of developing CVD was evaluated using FRS questionnaire. The association between dietary patterns and risk of development of CVD was evaluated using binary logistic regression models.

RESULTS

Three major dietary patterns were identified, which explained 32% of total variance in dietary intake of participants. The healthy dietary pattern was characterized by high intake of fruits, fruit juices, vegetables, liquid oils, and nuts and lower intake of refined grains. The western dietary pattern was characterized by high intake of fast foods, soft drinks, sweets and sugars, and red meat, organ meat, and egg. The traditional dietary pattern was characterized by high intake of legumes and vegetables and low intake of high-fat dairy products. After adjustment for all confounding factors, participants in the highest tertile of the healthy dietary pattern had a lower risk of CVD development (odds ratio [OR]: 0.67; 95% CI: 0.51-0.87, P-trend: 0.003).

CONCLUSION

Our findings in a large cohort of Iranian population confirm the current recommendation regarding consuming healthy dietary pattern for primary prevention of CVDs.

Dietary factors influence the association of cyclin D2 polymorphism rs11063069 with the risk of metabolic syndrome

The relationship of CCND2 gene variation, rs11063069 with metabolic syndrome (MetS) modulates by dietary factors but enough data are not available on this issue. So, the hypothesis, which assumes that dietary factors modulate the relationship of CCND2 polymorphisms with the risk of MetS was investigated in our study. Subjects of this nested case-control study were selected from participants of the Tehran Lipid and Glucose Study. Each case (n=974) was pair-matched individually with a control by age, sex and the follow-up duration. Dietary patterns were determined using factor analysis. CCND2 rs11063069 was genotyped by the ARMS-polymerase chain reaction analysis. Two dietary patterns were extracted: the healthy dietary pattern (HDP) and the Western dietary pattern; among G allele carriers, being in the highest quartiles of HDP score decreased risk of MetS (OR, Q1:3.01 [1.95-6.15], Q4:0.88 [0.39-1.78], P trend=.001), compared with those in the lowest quartile. In addition, the consumption of some vegetables, red-yellow vegetable (tomatoes, squash and carrots) and fruits by G allele carriers could decrease the risk of high fasting plasma glucose (P interaction=.003), low HDL-C (P interaction=.03) and high blood pressure (P interaction=.01) respectively. No significant interaction was observed in this study between nutrients (macronutrients, zinc, magnesium and iron) and CCND2 rs11063069 in relation to MetS or its components in this study. Our findings showed that by promoting adherence to HDP and increasing intake of some vegetables and fruits, the risk of MetS or its components reduced in G allele carriers; these associations were not observed in the AA genotype group.

The interaction of fat mass and obesity associated gene polymorphisms and dietary fiber intake in relation to obesity phenotypes

Controversies surrounding the effectiveness of fiber intake for prevention of obesity can be attributed to differences in the genetic makeup of individuals. This study aims to examining the interaction between dietary fiber intake and common fat mass and obesity–associated (FTO) single-nucleotide polymorphisms (SNPs), in relation to obesity. Subjects of this nested case-control study were selected from among adult participants of the Tehran Lipid and Glucose Study. Cases (n = 627) were individually matched with controls, who had normal weight. Six selected SNPs (rs1421085, rs1121980, rs17817449, rs8050136, rs9939973, and rs3751812) were genotyped by tetra-refractory mutation system-polymerase chain reaction analysis. Genetic risk scores (GRS) were calculated using the weighted method. A significant interaction was observed between total fiber intake and the GRS in relation to obesity (Pinteraction = 0.01); the difference in the risk for obesity was more pronounced in individuals with GRS ≥ 6 who consumed ≥ 14 grams of fiber a day (OR: 2.74, CI: 2.40–3.35 vs Ref.; P trend = 0.0005) than in individuals with GRS < 6 (P trend = 0.34). Dietary fiber intakes modified the association of FTO SNPs and the GRS with general obesity, an effect which was more pronounced in those who consumed high levels of dietary fiber and had a high number of risk alleles.

Mediterranean Dietary Pattern Adherence Modify the Association between FTO Genetic Variations and Obesity Phenotypes

There is increasing interest of which dietary patterns can modify the association of fat mass and obesity associated (FTO) variants with obesity. This study was aimed at investigating the interaction of the Mediterranean dietary pattern (Med Diet) with FTO polymorphisms in relation to obesity phenotypes. Subjects of this nested case-control study were selected from the Tehran Lipid and Glucose Study participants. Each case was individually matched with a normal weight control (n = 1254). Selected polymorphisms (rs1421085, rs1121980, rs17817449, rs8050136, rs9939973, and rs3751812) were genotyped. Genetic risk score (GRS) were calculated using the weighted method. The Mediterranean dietary score (MDS) was computed. Individuals with minor allele carriers of rs9939973, rs8050136, rs1781749, and rs3751812 had lower risk of obesity when they had higher MDS, compared to wild-type homozygote genotype carriers. The obesity risk was decreased across quartiles of MDS in participants with high GRS (OR: 1, 0.8, 0.79, 0.67) compared to individuals with low GRS (OR: 1.33, 1.06, 0.97, 1.12) (Pinteraction < 0.05). No significant interaction between the GRS and MDS on abdominal obesity was found. A higher Med Diet adherence was associated with lower obesity risk in subjects with more genetic predisposition to obesity, compared to those with lower adherence to the Med Diet and lower GRS.

Some dietary factors can modulate the effect of the zinc transporters 8 polymorphism on the risk of metabolic syndrome

There are conflicting data on the impact of zinc transporter 8 (ZNT8) gene variations on the metabolic syndrome (MetS). Hence, the effects of the interaction between rs13266634 and dietary factors on the risk of MetS were investigated in this study. Subjects of this nested case-control study were selected from the participants in Tehran Lipid and Glucose Study. Each of the cases (n = 817) was individually matched with a control. Dietary patterns were determined using factor analysis. The ZNT8 rs13266634 were genotyped by the Tetra-refractory mutation system-polymerase chain reaction analysis. Two dietary patterns were extracted. There were no significant interactions between the ZNT8 SNP and the dietary patterns on the risk of MetS or its components. An interaction was observed between rs13266634 and the omega-3 fatty acid intakes on the risk of MetS in subjects with the CC genotype (P interaction < 0.01). Zinc modified the association of the ZNT8 variant with high fasting blood sugar (P interaction = 0.05) in CC genotype carriers. An interaction was also observed between rs13266634 and salty snacks at the risk of abdominal obesity (P interaction < 0.05). Our findings suggest an interaction between omega-3 fatty acids, zinc, salty snacks and rs13266634, which may affect the risk of MetS or its components.

The Effect of Interactions of Single Nucleotide Polymorphisms of APOA1/APOC3 with Food Group Intakes on the Risk of Metabolic Syndrome

BACKGROUND

The aim of this study was to examine the interaction of dietary food groups and genetic variants of APOA1/APOC3, relative to Metabolic Syndrome (MetS) risk in adults.

METHODS

In this matched nested case-control study, 414 MetS subjects and 414 controls were selected from among participants of Tehran Lipid and Glucose Study. Dietary intake was assessed with the use of a valid and reliable semi-quantitative food frequency questionnaire. Single Nucleotide Polymorphisms (SNPs), APOA1 (rs670, -75G>A and rs5069, +83C>T/APOC3 rs5128 C3238>G) were genotyped by the conventional polymerase chain reaction and restriction fragment length polymorphism.

RESULTS

The mean (SD) of age was 40.7 (13) and 41.2 (13) years in male cases and controls versus 44.0 (11) and 44.0 (12) years in female case and controls. A significant interaction between intake quartiles of the sugar group and APOA1 combined group (GA+AA/CT+TT) SNPs was found; The ORs for these genotype carriers were (1, 0.44, 0.36, 0.23; P trend<0.001) in quartiles of intake, relative to other combined genotypes (P interaction=0.02). MetS risk appeared to be increased significantly in higher quartiles of sweet beverages and fish intakes in the GA+AA/CT+TT/CC genotypes of APOA1/APOC3 SNPs, compared to other genotypes (P interaction=0.01). The combined effect of genotypes of APOC3/APOA1 showed further decrease in MetS risk in higher quartiles of sugar group intakes (OR: 1, 0.24, 0.26, 0.14, P trend=0.001) relative to other combinations (P interaction=0.008).

CONCLUSION

Results obtained demonstrate that some dietary food groups (sugar, fish, and sweet beverages) modulate the effect of APOA1/APOC3 SNPs in relation to MetS risk.

Associations of Pre-Defined Dietary Patterns with Obesity Associated Phenotypes in Tehranian Adolescents

Obesity has become a public health problem in adolescents and could be a risk factor for both short-term and long-term health consequences. This study aimed to evaluate the relationship of Dietary Guidelines for Americans Adherence Index (DGAI), Healthy Eating Index-2005 (HEI-2005) and Healthy Eating Index-2010 (HEI-2010) with risk of obesity associated phenotypes in Tehranian adolescents. This cross-sectional study was conducted within the framework of the Tehran Lipid and Glucose Study, on 722 adolescents, aged 10–19 years. Usual dietary intakes were assessed by a food frequency questionnaire, and diet quality scores were obtained based on DGAI, HEI-2005 and HEI-2010. General obesity and cardio metabolic risk factors were defined according to the Centers of Disease Control and Prevention and de’Ferranti cut-offs, respectively. After adjusting for age, sex, energy intake and physical activity, compared to those in the lowest quartile, participants in the highest quartile of HEI-2010 had lower risk of general obesity (OR: 0.62; 95% CI: 0.38–0.93; P_trend = 0.03) and central obesity (OR: 0.63; 95% CI: 0.44–0.95; P_trend = 0.04). No association was observed between different types of obesity and scores of other diet quality indices. In conclusions, considering the role of HEI-2010 in decreasing the risk of obesity, these findings suggest that HEI-2010 may be useful for assessing diet-related progress in obesity prevention efforts.

Effect of interactions of polymorphisms in the Melanocortin-4 receptor gene with dietary factors on the risk of obesity and Type 2 diabetes: a systematic review

AIM

To perform a systematic review of the effect of interaction between Melanocortin-4 receptor (MC4R) single nucleotide polymorphisms and diet on the development of obesity and Type 2 diabetes.

BACKGROUND

Environmental factors, such as nutrient intakes or feeding behaviours, can modulate the association of polymorphism in the MC4R gene with obesity and Type 2 diabetes mellitus.

METHODS

A systematic literature search was conducted in the PubMed, Scopus and Google Scholar databases, with a combination of the following keywords: Diet*, nutr*, melanocortin receptor, melanocortin 4 receptor and MC4R. To assess the quality of observational studies, we used a 12-item quality checklist, derived from the STREGA statement.

RESULTS

A total of 14 articles were selected based on the inclusion and exclusion criteria. Consumption of highly salty foods and adherence to a Mediterranean dietary pattern can modulate the association between MC4R polymorphisms and the risk of obesity or Type 2 diabetes. Despite the highly contradictory results of intervention studies, after short-term lifestyle interventions, children with variant alleles of MC4R single nucleotide polymorphisms can lose more body weight, compared with non-carriers, although they may have difficulty in maintaining this weight loss in the long-term. To interpret the results of studies on adults, we need further studies.

CONCLUSIONS

The interaction between MC4R genes with dietary factors plays a significant role in the development of obesity or Type 2 diabetes phenotypes. Early detection of MC4R risk alleles in individuals and modification of their diet based on these results could be an efficient strategy to prevent obesity or diabetes in these subgroups.