[Association between nutrient patterns and changes in weight and waist circumference in Tehranian adults: Tehran lipid and glucose study]

Introduction: The association of nutrient patterns with chronic disease and obesity has been much focused on recently. This study investigated the relation between nutrient patterns with changes in weight and waist circumference

Materials and Methods: The study population included 1637 subjects, aged 30-75 years, free of cardiovascular diseases, and cancer, recruited from Tehran Lipid and Glucose Study [2005-2008]. Participants had complete anthropometric and dietary information and were followed up to the next phase [2008-2011]. Dietary intake of 33 nutrients was collected by a valid and reliable food frequency questionnaire and three year changes of weight and waist circumference were documented. Nutrient patterns were obtained using principal component analysis

Results: Four nutrient patterns were identified. Median and interquartile range [IQR] of weight and waist circumference changes of participants were 1.0 [-1.0-3.0] kilogram and 3.0 [0.0-8.0] centimetres, respectively. The first pattern [high fat dairy and meat], rich in animal protein, saturated fatty acid, cholesterol, vitamin D, riboflavin, pantothenic acid, vitamin B12, calcium, phosphorous and zinc was associated with higher weight gain 0.258 [0.066-0.449] P for trend=0.009 after adjusting for confounder variables. There were no significant associations for other patterns [fruit and vegetables with dairy, nuts and legumes, and grains and fruits] with changes in weight and waist circumference

Conclusion: Dietary intakes of nutrient patterns rich in animal source foods are directly associated with higher weight gain

Assessment of relationship between dietary patterns and incidence of hypertension: tehran lipid and glucose study

Identifying different food patterns may play a role in reducing the incidence of hypertension. Since most studies in this field have been cross-sectional, studies demonstrating HTN incidence are very limited. Hence we conducted this longitudinal study to determine dietary patterns and their effects on the incidence of hypertension. Dietary patterns of 1787 subjects, aged 20-60 yrs, who participated in phase 3 of Tehran Lipid and Glucose Study [TLGS] were determined using factor analysis and the association between dietary patterns and the incidence of hypertension in phase 4 of TLGS was assessed, using logistic regression. Mean age across quartiles of healthy and western dietary patterns differed significantly. Individuals with lowest adherence to healthy dietary pattern and highest adherence to western dietary pattern were younger than others. Participants in the highest quartile of the healthy dietary pattern were physically more active than those in the upper quartile of western dietary pattern, who had the lowest level of physical activity. The healthy dietary pattern was negatively associated with elevated systolic blood pressure in models 2 [adjusted for age, sex, education, smoking and BMI] and 3 [adjusted for age, sex, education, smoking and BMI and physical activity] [odds ratio: 0.74 [95% Cl: 0.56-0.98] and 0.74 [95% Cl: 0.56-0.97] respectively, P=0.03 for both]. Results of this study showed that adherence to the healthy dietary pattern reduced the risk of incidence of hypertension by 26%

[ association between dietary energy density and the risk of type 2 diabetes: Tehran lipid and glucose study]

Dietary energy-dense foods predispose to obesity and may be associated with risk of type 2 diabetes; therefore, the aim of our study was to investigate the association between dietary energy density [DED] and the risk of type 2 diabetes. In this matched nested case-control study, 178 new onset cases of diabetes were selected from among participants of the Tehran Lipid and Glucose Study, and followed for over 9 years. Each case was randomly matched with 3 controls from among participants who had not developed diabetes. Dietary intakes were determined using a valid and reliable food frequency questionnaire. DED was calculated as energy intakes [kcal] from foods and beverages divided by the weight [grams] of foods. The mean ages of participants were 43 +/- 6.5 and 44.5 +/- 12 years, in women and men respectively. Individuals with higher DED had higher calories, total fat, carbohydrate and processed meat intakes and lower fruit and vegetable intakes in men and women [P<0.05]. Energy density was positively associated with incident diabetes in women, after adjustment for diabetes risk factors and total calorie intake [OR: 2.28, P trend=0.02] or total fat intake [OR: 2.15, P trend=0.03], an association which was not significant in men. In this nested case-control study, there was positive association between DED and risk of type 2 diabetes in women

[Interaction of APOC3 polymorphism and dietary fats on the risk of metabolic syndrome]

The aim of this study was to evaluate the interaction between dietary fatty acids and the genetic variant of APOC3 rs5128 3238C>G in relation to metabolic syndrome [MetS] components in adults. In this matched nested case-control study, 755 MetS subjects and 755 controls were selected from among participants of the Tehran Lipid and Glucose Study. Dietary intake was determined using a valid and reliable food frequency questionnaire. APOC3 was genotyped by the conventional polymerase chain reaction and restriction fragment length polymorphism. Mean ages of men and women were not different in cases and controls. The frequency of C allele was 81%, which did not differ in cases and controls or in men and women. Compared to CC genotype, low HDL-C risk was increased in women with the CG+GG genotypes and with cholesterol intakes >/=208 mg/day [OR: 1.93]. In men with the CG+GG genotypes and saturated fatty acid [SFA] intakes >/=9.8% of energy, OR of high diastolic blood pressure [BP] was 2.15[1-1.46], compared to individuals with SFA intake <9.8% of energy and CC genotype. Compared to the CC genotype, the risk of high diastolic BP was higher in men carrying the G allele and consuming mono-unsaturated fatty acid [MUFA] intakes >/=9.4% of energy. Results demonstrate a nutri-genetic interaction between rs5128 and fat intakes in relation to components of MetS; individuals with G allele carriers and higher intakes of cholesterol, MUFA or SFA had higher risk of low HDL-C and hypertension than the CC genotype

[Diet quality and its relationship with metabolic syndrome in adolescents: Tehran lipid and glucose study]

The "Dietary Guidelines for Americans Adherence Index [DGAI] " was developed based on the adherence to the dietary recommendations of the Dietary Guidelines for Americans 2005 [DGA-2005] to assess the contribution of dietary patterns to chronic diseases. The objective of this study was to evaluate the association of dietary patterns as measured by the modified DGAI with the prevalence of metabolic syndrome [MetS] and its components in Tehranian adolescents. In this cross-sectional study, 706 adolescents aged 10 to 19 years, participated from the fourth phase of the Tehran Lipid and Glucose Study. Usual dietary intake was assessed using a valid food frequency questionnaire, and the DGAI score was calculated for all participants. MetS was defined according to de Ferranti criteria. The most prevalent risk factor for MetS was high waist circumference [51.8%]. After adjusting for confounding variables, those in the highest quartile category of DGAI had a 36% lower risk of low HDL-C [odds ratio=64%, 95% CI: 0.41-0.98 and P for trend=0.03] and 50% lower risk of hypertension [odds ratio=50%, 95% CI: 0.25-0.99 and P for trend=0.02], compared with the lowest quartile. Increasing adherence to DGAI showed no significant difference in risk of hypertriglyceridemia, hyperglycemia, high waist circumference, MetS, mean body mass index [BMI] or physical activity scores. In adolescents, increasing adherence to Dietary Guidelines for Americans 2005 [DGA-2005] had only an inverse association with low HDL-C and hypertension, but had no relationship with the risk of MetS and its other components

Association between dietary fiber intake and metabolic syndrome: tehran lipid and glucose study

There is little known about the relation between metabolic syndrome and fiber intake are available in Iran. We evaluated the relation between total, and various types and sources of dietary fiber and the prevalence of the metabolic syndrome. In this cross sectional study, 2457 adults, aged 19-84 years were studied. Total dietary fiber intake and its types and sources were assessed using a validated semi quantitative food-frequency questionnaire. Blood pressure, Anthropometrie, and biochemical measurements were assessed. The metabolic syndrome was defined according to definition by Iranien National Committee of Obesity. In the multivariate-adjusted odds ratio, intakes of total [OR: 0.53; 95% CI: 0.39-0.74], both soluble [OR: 0.60; 95% Cl: 0.43-0.84] and insoluble dietary fiber [OR: 0.51; 95% CI: 0.35-0.72], fruit fiber [OR: 0.51; 95% CI: 0.37-0.72], legume fiber [OR: 0.73; 95% CI: 0.53-0.99] and cereal fiber [OR: 0.74; 95% CI: 0.57-0.97] were inversely associated with the metabolic syndrome. There was not significant association between usîng vegetable and nut fiber and prevalence of metabolic syndrome. Total dietary fiber, both soluble and insoluble fibers, and especially fruit and legumes fibers, reduce the metabolic syndrome among adults in Tehran

[Food patterns of Tehranian adolescents and their relation to anthropometric measures and blood pressure: Tehran lipid and glucose study]

Adolescence is an important stage in life for establishing dietary habits. There is little evidence on adolescent dietary patterns and related risk factors. The aim of this study was to determine food patterns among Tehranian adolescents and any associations to anthropometric measures and blood pressure. In this study, 507 adolescents, aged 10 to 19 years, were assessed. Dietary intakes were evaluated by means of a validated semi-quantitative questionnaire, and anthropometric indices [weight, height, and waist circumference] and blood pressure were measured and recorded. The Kriska physical activity questionnaire was used for determination of physical activity levels. Using principal component analysis with varimax rotation for 21 food groups, two dietary patterns were derived. In the healthy dietary pattern, whole grain, low fat dairy and vegetables, and in the unhealthy pattern, sweetened drinks, fast food and refined cereal pattern were included. Significant differences were observed in the healthy dietary pattern between boys and girls, as well as, among different age groups. There was significant association between the unhealthy dietary pattern scores and physical activity [P<0.05]. After adjustment of confounding factors, significant associations were found between unhealthy dietary pattern scores and body mass index and waist circumference [P<0.05]. However, no significant association was observed between blood pressure and the two dietary patterns. Adherence to unhealthy dietary patterns was an important determinant in increase in body mass index and consequently in central obesity among adolescents

[Dietary fructose and cardiovascular disease risk factors in adults: Tehran lipid and glucose study]

The aim of this study was to investigate the association between fructose intake and cardiovascular disease risk factors in Tehranian adults. This study was conducted using data from adults, aged 19-70 years, who participated in the third phase of Tehran Lipid and Glucose study. Dietary data were collected using a validated semi-quantitative food frequency questionnaire with 168 food items. The sum of natural dietary fructose in fruits and vegetables, and fructose in industrialized foods containing added sweeteners, was calculated as total dietary fructose. Forty-five and fifty-five percent of participants were men and women, with mean ages of 40.5 +/- 13.6 and 38.6 +/- 12.8 years, respectively. Mean dietary intakes of total fructose were 46.5 +/- 24.5 g/d in men and 37.3 +/- 24.2 g/d in women. Significant positive associations were observed between dietary fructose intake and body mass index [beta =0.03 and 0.11, p<0.001, in men and women respectively], systolic blood pressure [beta =0.09 and 0.12, p<0.01, in men and women respectively], diastolic blood pressure [beta =0.13 and 0.80, p<0.01, in men and women respectively] and fasting blood glucose in men [beta =0.01, p<0.05]. Dietary fructose intake may have adverse effects on cardiovascular disease risk factors

[Prevalence trends in adolescent overweight and hypertension in the three cross-sectional surveys of Tehran lipid and glucose study, 1999-2008]

This study aims at determining the trends of the prevalence of overweight and hypertension among adolescents in three cross-sectional surveys of Tehran Lipid and Glucose Study [TLGS]. We analyzed the data of adolescents, aged 10-19 years, obtained in the three surveys of the TLGS; survey 1, 1999-2001 [n=3010, 47.2% boys]; survey 2, 2002-5 [n=1107, 48.4% boys], and survey 3, 2006-8 [n=1090, 46.6% boys]. At risk for overweight and overweight were defined according to Iranian BMI percentiles. Hypertension was defined according to the fourth report on the Diagnosis, Evaluation and Treatment of High Blood Pressure [BP], American Academy of Pediatrics and charts of the Centers for Disease Control and Prevention. Mean BMI of adolescents increased from 20.1 [4.3] in survey 1 to 21.6[4.7] kg/m2 in survey 3[P<0.001]. The adjusted prevalence of at risk for overweight, in the first and third surveys of study increased respectively from 12.8% to 18.5% [P<0.001] and the prevalence of overweight increased from 6.4 to 12.7% respectively [P<0.001]. The mean systolic BP and diastolic BP decreased from 105[11], 71.4[9.2] in the first survey to 100[12], 65.4[9.8] mmHg in the third, respectively [P<0.001]. The prevalence of high systolic BP and diastolic BP decreased from 3 and 7.9% in 1999-2001 to 1.3 and 3% in 2006-8, respectively. The age adjusted means of SBP and DBP increased respectively in underweight, normal, at risk for overweight and overweight adolescents [P<0.01]. The increment of [overweight prevalence] was greater than [at risk for overweight]. The prevalence of high systolic and diastolic BP decreased over the three surveys

[Change in food patterns and its relation to alterations in central adiposity in Tehranian of district 13 adults]

Obesity and its complications are a major health problem in Iran. The aim of this longitudinal study was to determine whether changes in food patterns were related to abdominal obesity in Tehranian adults of district 13. A total of 82 men and 124 women, [>/= 18 years old], were studied between 1999-2001 and 2004-2007. Subjects with abdominal obesity were defined according to ATPIII and WHO guidelines. Dietary intake was assessed by a food frequency questionnaire and two 24-hour dietary recalls. Food groups were determined according to their nutrients contents and previous literature. Food patterns were derived by factor analysis at each time point. The factor scores for each pattern for each subject were calculated by the amount of the intakes of each of the food groups weighted by their factor analysis coefficient matrix; the scores were then standardized [mean=0, SD=1]. Changes in food pattern, waist circumference [WC] and waist to hip ratio [WHR] were defined by subtracting the factor score for each food pattern and anthropometric measurements in the two time intervals. Men and women were 51 +/- 11 and 45 +/- 14 years of age at the end of study respectively. During the two periods of the study, mean WC increased from 89.5 +/- 10.4 to 97.6 +/- 9.1 in men and from 84.8 +/- 13.2 to 88.4 +/- 12.4 cm in women [p<0.05]. Three dietary patterns were identified and named by factor analysis as follows: Healthy [HDP], Western [WDP] and Mix[MDP]. In the WDP, salty snacks and sauces had the highest and in the HDP, vegetables had the highest and whole grain had the lowest loading factors in the two study periods. After adjusting for confounding factors better prediction of WC change was obtained in normal individuals with WDP change[beta=0.49, R2=0.21, p<0.01] compared with HDP[beta=-0.20, R2=0.11, p<0.05]. Change in WDP and HDP were related to the WHR change in abdominally obese persons [beta =0.21, R2=0.21, p<0.05], [beta =-0.23, R2=0.22, p<0.01] respectively. Results of this study indicate that adherence to HDP and decreasing intake of WDP items prevent central adiposity