Parvin Mirmiran

OBJECTIVE: To describe the relative validity and reliability of the FFQ used for assessing nutrient intakes of participants in the Tehran Lipid and Glucose Study (TLGS). DESIGN: A total of 132 subjects (sixty-one males and seventy-one females) were included in the study. Dietary data were collected monthly by means of twelve 24 h dietary recalls (24hDR). Subjects completed two, 168-item semi-quantitative FFQ. Blood and urine samples were taken every season for measurement of plasma biomarkers and urinary N and K. RESULTS: Mean age and BMI of the participants were 35.5 (sd 16.8) years and 25.5 (sd 5.2) kg/m2, respectively. The mean energy-adjusted and deattenuated correlation coefficients for overall nutrient intake between the 24hDR and FFQ2 were 0.44 and 0.37 in <or=35-year-olds and >35-year-olds, respectively, and for individual nutrients ranged from 0.24 to 0.71 in men (mean r = 0.53) and from 0.11 to 0.60 in women (mean r = 0.39). The mean energy-adjusted reliability coefficients varied from 0.48 in <or=35-year-olds to 0.65 in >35-year-olds, and ranged from 0.41 to 0.79 in men (mean r = 0.59) and from 0.39 to 0.74 in women (mean r = 0.60). The FFQ2 and 24hDR produced exact agreement rates ranging between 39.6 % and 68.3 % in men and between 39.6 % and 54.1 % in women. The ranges of questionnaire validity coefficients, with the sample correlation between the questionnaires and biochemical marker as the lower limit and the estimate obtained by the method of triads as the upper limit, were 0.21-0.56 (protein) and 0.37-0.61 (K). CONCLUSIONS: The FFQ developed for the TLGS has reasonable relative validity and reliability for nutrient intakes in Tehranian adults.

BACKGROUND: The Tehran Lipid and Glucose Study (TLGS) is a long term integrated community-based program for prevention of non-communicable disorders (NCD) by development of a healthy lifestyle and reduction of NCD risk factors. The study begun in 1999, is ongoing, to be continued for at least 20 years. A primary survey was done to collect baseline data in 15005 individuals, over 3 years of age, selected from cohorts of three medical heath centers. A questionnaire for past medical history and data was completed during interviews; blood pressure, pulse rate, and anthropometrical measurements and a limited physical examination were performed and lipid profiles, fasting blood sugar and 2-hours-postload-glucose challenge were measured. A DNA bank was also collected. For those subjects aged over 30 years, Rose questionnaire was completed and an electrocardiogram was taken. Data collected were directly stored in computers as database software- computer assisted system. The aim of this study is to evaluate the feasibility and effectiveness of lifestyle modification in preventing or postponing the development of NCD risk factors and outcomes in the TLGS population. DESIGN AND METHODS: In phase II of the TLGS, lifestyle interventions were implemented in 5630 people and 9375 individuals served as controls. Primary, secondary and tertiary interventions were designed based on specific target groups including schoolchildren, housewives, and high-risk persons. Officials of various sectors such as health, education, municipality, police, media, traders and community leaders were actively engaged as decision makers and collaborators. Interventional strategies were based on lifestyle modifications in diet, smoking and physical activity through face-to-face education, leaflets & brochures, school program alterations, training volunteers as health team and treating patients with NCD risk factors. Collection of demographic, clinical and laboratory data will be repeated every 3 years to assess the effects of different interventions in the intervention group as compared to control group. CONCLUSION: This controlled community intervention will test the possibility of preventing or delaying the onset of non-communicable risk factors and disorders in a population in nutrition transition. TRIAL REGISTRATION: ISRCTN52588395.

OBJECTIVE: To examine the validity and reproducibility of food groups in the semi-quantitative food frequency questionnaire (FFQ) developed for the Tehran Lipid and Glucose Study (TLGS). METHODS: To evaluate the reproducibility of food groups included in the FFQ, 132 subjects (61 men and 71 women) aged 20 years or older twice completed a 168-item FFQ (FFQ1, FFQ2), with a 14-month interval between FFQ1 and FFQ2. Over the 1-year interval, 12 dietary recalls (DRs) were collected (1 each month) to assess the validity of the FFQ. Seventeen food groups were derived from the FFQ based on methods described in previous studies. Age-adjusted and deattenuated Spearman correlation coefficients were used to assess the validity of the FFQ. RESULTS: The mean (SD) age and body mass index of subjects were 35.5 (16.8) years and 25.5 (5.2) kg/m(2), respectively. Validity correlation coefficients ranged from 0.03 (liquid oil) to 0.77 (simple sugars) in men (median, 0.44), and from 0.12 (snacks) to 0.79 (simple sugars) in women (median, 0.37). The energy-adjusted intraclass correlation coefficient, which reflects the reproducibility of the FFQ, was 0.51 in men and was highest for tea and coffee (0.91); in women it was 0.59 and was highest for simple sugars (0.74). The highest percentage of complete agreement and disagreement was observed for snacks and desserts (60.6%) and potatoes and dairy products (12.8%), respectively, in men, and tea and coffee (62.9%) and legumes (15.7%) in women. CONCLUSIONS: The FFQ that was designed for the TLGS was found to be reliable and valid for assessing the intake of several food groups.

In recent years, there is growing evidence that plant-foods polyphenols, due to their biological properties, may be unique nutraceuticals and supplementary treatments for various aspects of type 2 diabetes mellitus. In this article we have reviewed the potential efficacies of polyphenols, including phenolic acids, flavonoids, stilbenes, lignans and polymeric lignans, on metabolic disorders and complications induced by diabetes. Based on several in vitro, animal models and some human studies, dietary plant polyphenols and polyphenol-rich products modulate carbohydrate and lipid metabolism, attenuate hyperglycemia, dyslipidemia and insulin resistance, improve adipose tissue metabolism, and alleviate oxidative stress and stress-sensitive signaling pathways and inflammatory processes. Polyphenolic compounds can also prevent the development of long-term diabetes complications including cardiovascular disease, neuropathy, nephropathy and retinopathy. Further investigations as human clinical studies are needed to obtain the optimum dose and duration of supplementation with polyphenolic compounds in diabetic patients.

OBJECTIVE: To determine the effects of a Dietary Approaches to Stop Hypertension (DASH) eating plan on metabolic risks in patients with the metabolic syndrome. RESEARCH DESIGN AND METHODS: This was a randomized controlled outpatient trial conducted on 116 patients with the metabolic syndrome. Three diets were prescribed for 6 months: a control diet, a weight-reducing diet emphasizing healthy food choices, and the DASH diet with reduced calories and increased consumption of fruit, vegetables, low-fat dairy, and whole grains and lower in saturated fat, total fat, and cholesterol and restricted to 2,400 mg Na. The main outcome measures were the components of the metabolic syndrome. RESULTS: Relative to the control diet, the DASH diet resulted in higher HDL cholesterol (7 and 10 mg/dl), lower triglycerides (-18 and -14 mg/dl), systolic blood pressure (SBP) (-12 and -11 mmHg), diastolic blood pressure (-6 and -7 mmHg), weight (-16 and -14 kg), fasting blood glucose (FBG) (-15 and -8 mg/dl), and weight (-16 and -15 kg), among men and women, respectively (all P < 0.001). The net reduction in triglycerides (-17 and -18 mg/dl), SBP (-11 and -11 mmHg), diastolic blood pressure (-5 and -6 mmHg), and FBG (-4 and -6 mg/dl), weight (-16 and -15 kg), and increase in HDL (5 and 10 mg/dl) among men and women, respectively, was higher in the DASH group (all P < 0.05). The weight-reducing diet resulted in significant change in triglycerides (-13 and -10 mg/dl), SBP (-6 and -6 mmHg), and weight (-13 and -12 kg) among men and women, respectively (all P < 0.05). CONCLUSIONS: The DASH diet can likely reduce most of the metabolic risks in both men and women; the related mechanisms need further study.