Parvin Mirmiran

Cardiovascular risk factors in an Iranian urban population: Tehran Lipid and Glucose Study (Phase 1)

Summary.Objectives: Coronary artery disease is becoming more prevalent in developing countries, particularly in urban areas. This study was conducted to determine the prevalence of cardiovascular risk factors among Tehran urban population.nMethods: The prevalence and distribution of high blood pressure, cigarette smoking, dyslipoproteinemia, diabetes mellitus, and obesity was determined in 15005 subjects, aged three years and over, selected by cluster random sampling in Tehran urban district-13 between February 1999 to August 2001. Total energy intake, percent of energy derived from protein, carbohydrate, and fat were assessed in a subsidiary of 1474 persons by means of two 24-hour dietary recalls.nResults: In adults, 78% of men and 80% of women presented at least one CVD risk factor. The percentage of adult women with two or more risk factors was significantly greater than the one for men. Prevalence of DM, hypertension, obesity, high TC, low HDL, high TGs, and smoking was 9.8, 20.4, 14.4, 19.3, 32, 5.3, and 22.3%, respectively. In children and adolescents, two or more CVD risk factors were found in 9% of boys and 7% of girls. Prevalence of hypertension, obesity, high TC, low HDL, and high TGs, was 12.7, 5.2, 5.1, 10.2, and 5%, respectively. The mean percentage values of energy intake derived from carbohydrate, protein, and fat were 57.8±6.9, 11.1±1.8, and 30.9±7.2, respectively.nConclusion: The prevalence of cardiovascular risk factors among Tehran urban population is high; particularly of high total cholesterol, low HDL cholesterol levels, and high waist to hip ratio. An effective strategy for life style modification is a cornerstone of a population approach to the cardiovascular risk factors. Moreover, these results will serve as a baseline for assessment of future trends in the risk factors studied.

Dairy consumption and body mass index: an inverse relationship.

OBJECTIVE:To assess the relationship between consumption of dairy products and body mass index (BMI) in Tehranian adults.DESIGN:Cross-sectional study.SUBJECTS:A total of 462 healthy subjects (223 men and 239 women) aged over 16 y selected randomly from among participants of the Tehran Lipid and Glucose Study (TLGS).MEASUREMENTS:Dietary data were collected by means of a food frequency questionnaire for 1 y and two 24-h dietary recalls. Height and weight were measured and BMI was calculated. Physical activity was assessed by the Lipid Research Clinic (LRC) questionnaire.RESULTS:Consumption of dairy products was 3.7±1.0 and 2.9±1.2 servings per day in men and women, respectively. As the servings of dairy consumption increased per day, the proportion of normal-weight subjects rose and that of obese ones declined. As BMI increased, the proportion of subjects with lower consumption of dairy products increased, whereas that of those with higher consumption decreased. There was a significant inverse correlation between the servings of dairy consumption per day and BMI after controlling for the effect of age, physical activity, energy, carbohydrate, dietary fiber, protein and fat intake (r=−0.38, P<0.05). After adjustment for potential confounding variables, men and women in the top quartile of dairy consumption had lower chances for being overweight (OR=0.78, 95% CI=0.43–0.92 for men and OR=0.89, 95% CI=0.53–0.95 for women) and obese (OR=0.73, 95% CI=0.40–0.83 for men and OR=0.69, 95% CI=0.34–0.80 for women) compared to those in the first quartile.CONCLUSION:The results suggest an inverse relationship between dairy consumption and BMI. It is recommended that further studies address this issue by focusing on the dairy components responsible for this effect.

Waist-to-hip ratio is a better screening measure for cardiovascular risk factors than other anthropometric indicators in Tehranian adult men.

BACKGROUND: It is essential to identify the best anthropometric index in any population to predict chronic disease risk.OBJECTIVE: To compare the ability of waist circumference (WC), body mass index (BMI), waist-to-hip ratio (WHpR) and waist-to-height ratio (WHtR) to predict cardiovascular risk factors in an urban adult population of Tehranian men.DESIGN: Population-based cross-sectional study.SUBJECTS: A representative sample of 4449 men aged 18–74u2009y, participants of the Tehran Lipid and Glucose StudyMETHODS: Demographic data were collected; anthropometric indices and blood pressure were measured according to standard protocol. In the 18–34u2009y age category, cutoff points for BMI, WHpR, WHtR and WC were 24u2009kg/m2, 0.86, 0.47 and 81u2009cm, respectively. In the 35–54u2009y age category these cut points were 26u2009kg/m2, 0.91, 0.52 and 89u2009cm, and in the 55–74u2009y age category 26u2009kg/m2, 0.95, 0.54 and 91u2009cm, respectively. Hypertension was defined based on JNC VI. Biochemical analysis was conducted on fasting blood samples. Diabetes was defined as fasting plasma glucose ≥126u2009mg/dl or 2hPG ≥200u2009mg/dl and dyslipidemia based on ATP III. The presence of ‘at least one risk factor’ from the three major cardiovascular risk factors (hypertension, dyslipidemia and diabetes) was also evaluated.RESULTS: Mean age of men was 41.8±15.4u2009y. Mean BMI, WHpR, WC and WHtR for subjects were 25.6±4.2u2009kg/m2, 0.91±0.07, 87.7±11.7u2009cm and 0.51±0.02, respectively. Dyslipidemia and ‘at least one risk factor’ are more prevalent risk categories. Although all anthropometric indicators had a significant association to cardiovascular risk factors, WHpR had the highest correlation coefficients compared to other anthropometric measures. For all risk factors in all age categories, the highest odds ratios were pertained to WHpR. Of the four individual indicators, WHpR had the highest sensitivity, specificity and accuracy to predict cardiovascular risk factors. Cutoff points for WHpR were seen to have a higher percentage of correct prediction than BMI, WC and WHtR in all age categories.CONCLUSION: It is concluded that WHpR is a better predictor for cardiovascular risk factors than BMI, WC and WHtR in Tehranian adult men.

Dietary diversity score and cardiovascular risk factors in Tehranian adults

AIMnTo evaluate the relationship between dietary diversity score (DDS) and cardiovascular risk factors in Tehranian adults.nnnMETHODSnIn this population-based cross-sectional study, a representative sample of 581 subjects (295 males and 286 females) aged over 18 years, residents of Tehran, participated. Hypercholesterolaemia, hypertriglyceridaemia and low high-density lipoprotein cholesterol were defined according to the Adult Treatment Panel III guidelines of the National Cholesterol Education Program. Diabetes was defined as fasting plasma glucose concentration > or = 126 mg dl(-1) or 2-h post challenge glucose concentration > or = 200 mg dl(-1). Hypertension was defined on the basis of the sixth report of the Joint National Committee on Prevention, Detection, Evaluation and Treatment of High Blood Pressure. Dietary diversity was defined according to the Diet Quality Index revised.nnnRESULTSnMean (+/- standard deviation) DDS was 6.15 +/- 1.02. The probability of having diabetes (odds ratio (OR) among quartiles: 1.45, 1.26, 1.11 and 1.00, respectively; P for trend = 0.04) and hypertriglyceridaemia (OR = 1.41, 1.23, 1.05 and 1.00, respectively; P for trend=0.04) decreased with increasing quartile of the diversity score for whole grains. The probability of having obesity (OR among quartiles: 1.39, 1.06, 1.03 and 1.00, respectively; P for trend = 0.03), hypercholesterolaemia (OR = 1.46, 1.28, 1.11 and 1.00, respectively; P for trend = 0.03), hypertension (OR = 1.32, 1.17, 1.13 and 1.00, respectively; P for trend = 0.03) and high low-density lipoprotein cholesterol (LDL-C) (OR = 1.25, 1.12, 1.07 and 1.00, respectively; P for trend = 0.04) decreased with increasing quartile of the diversity score for vegetables. The probability of having hypercholesterolaemia, high LDL-C, hypertension and diabetes decreased with quartile of the DDS. But the probability of being obese increased with quartile of the DDS (P for trend = 0.03).nnnCONCLUSIONnDDS was inversely associated with cardiovascular risk factors in this cross-sectional study. Increased diversity scores of diets, to increase the variety score for vegetables, may be emphasised in programmes attempting to bring about changes in lifestyle.

Dietary diversity score is favorably associated with the metabolic syndrome in Tehranian adults

OBJECTIVE:Assessing overall diet instead of the effects of a single nutrient on diet–disease relations may be more informative. This study was conducted to evaluate the relationship between dietary diversity score (DDS) and metabolic syndrome in Tehranian adults.DESIGN:Cross-sectional study.SUBJECTS:A representative sample of 581 healthy subjects aged over 18u2009y selected randomly from among participants of the Tehran Lipid and Glucose Study.MEASUREMENTS:Usual dietary intake was assessed using a validated semi quantitative food frequency questionnaire. DDS was calculated based on scoring to the five-food group. The DDS range was 0–10. Weight and height were measured according to standard protocols and body mass index (BMI) was calculated. Fasting blood samples were taken for biochemical measurements and blood pressure was assessed according to standard methods. Metabolic syndrome was defined according to ATPIII. Subjects were categorized based on quartile cut-points of DDS.RESULTS:Means (±s.d.) of age and BMI were 37±12u2009y and 25.7±4.3u2009kg/m2, respectively. Mean (±s.d.) of DDS was 6.15±1.02. The probability of having metabolic syndrome decreased with quartiles of DDS (odds ratios among quartiles: 1.00, 0.82, 0.76, 0.70, P<0.05, and odds ratios among quartiles after further adjustment for BMI: 1.00, 0.88, 0.80, 0.77, P<0.05). After controlling for confounders, a significantly decreasing trend was observed for the risk of having high blood pressure, impaired glucose homeostasis and high triglyceride levels.CONCLUSION:DDS had inverse association with metabolic syndrome and some of its features in this cross-sectional study. A higher dietary diversity, therefore, might be associated with lower possibility of having some metabolic disorders.

Comparative evaluation of anthropometric measures to predict cardiovascular risk factors in Tehranian adult women.

OBJECTIVEnTo compare the ability of waist circumference (WC), body mass index (BMI), waist-to-hip ratio (WHR) and waist-to-height ratio (WHtR) to predict cardiovascular risk factors in an urban adult population of Tehranian women.nnnDESIGNnPopulation-based cross-sectional study.nnnSETTINGnTehran, the capital of Iran.nnnSUBJECTSnThis study was conducted on 5073 women aged 18-74 years, participants of the Tehran Lipid and Glucose Study. Demographic data were collected. Anthropometric indices were measured according to standard protocols. Cut-off points of BMI, WC, WHR and WHtR were considered as 25 kg m(-2), 80 cm, 0.8 and 0.5, respectively. Blood pressure was measured and hypertension was defined based on the sixth report of the Joint National Committee on Prevention, Detection, Evaluation and Treatment of High Blood Pressure. Biochemical analyses were conducted on fasting blood samples. Diabetes was defined as fasting plasma glucose > or = 126 mg dl(-1) or 2-hour plasma glucose > or = 200 mg dl(-1) and dyslipidaemia based on the third report of the National Cholesterol Education Program Expert Panel. The presence of at least one risk factor from the three major cardiovascular risk factors (hypertension, dyslipidaemia and diabetes) was also evaluated.nnnRESULTSnMean (+/-standard deviation) age of women was 39.9+/-14.6 years; mean BMI, WC, WHR and WHtR were 27.1+/-1.5 kg m(-2), 86.5+/-13.5 cm and 0.83+/-0.08 and 0.55+/-0.08, respectively. Of the four anthropometric measures, WC had the highest sensitivity and specificity to identify subjects with risk factors in both the 18-39 year and the 40-74 year age categories. WC was seen to have a higher percentage of correct prediction than BMI, WHR and WHtR.nnnCONCLUSIONnIt is concluded that WC is the best screening measure for cardiovascular risk factors, compared with BMI, WHR and WHtR, in Tehranian adult women.

Urinary iodine excretion in pregnant women residing in areas with adequate iodine intake

OBJECTIVEnPregnancy is accompanied by profound alterations in thyroid economy and relative iodine deficiency. The aim of this study was to evaluate urinary iodine excretion of pregnant women in cities with adequate and more than adequate iodine intake.nnnMETHODSnA cross-sectional study was performed on schoolchildren and pregnant women in four cities in the Islamic Republic of Iran. Urinary iodine excretion was measured for 438 schoolchildren and 403 pregnant women. In addition, in Isfahan City, thyroid volume was measured by sonography for 30 pregnant women in each trimester of pregnancy and for 90 non-pregnant women who also had urinary iodine measurement.nnnRESULTSnMedian urinary iodine of schoolchildren was 31.2, 25.0, 20.2 and 19.3 microg/dl in Rasht, Isfahan, Ilam and Tehran, respectively. Corresponding values for pregnant women were 33.8, 21.2, 19.0 and 18.6 microg/dl. The percentage of pregnant women with urinary iodine below 20 microg/dl was 16, 45, 55 and 54, and below 10 microg/dl was 1, 7, 7 and 13, in Rasht, Isfahan, Ilam and Tehran, respectively. In Isfahan, urinary iodine was significantly decreased in the third trimester of pregnancy, compared with controls. Mean thyroid volume was 7.8 +/- 3.1 ml and 7.8 +/- 2.8 ml in pregnant and non-pregnant women, respectively.nnnCONCLUSIONnRecommended values for dietary iodine through universal salt iodisation may not be adequate for pregnant women, and the specific problem of iodine and pregnancy should be considered further in the light of the latest recommendations.

Dietary behaviour of Tehranian adolescents does not accord with their nutritional knowledge

OBJECTIVEnTo determine the nutritional behaviour of Tehranian adolescents.nnnSUBJECTS AND METHODSnThis study was undertaken on 7669 adolescents (4070 boys and 3599 girls) of 22 junior high schools and high schools as a representative sample of Tehranian adolescents. A validated knowledge, attitudes and practices (KAP) questionnaire and a food-frequency questionnaire (FFQ) were used. Factor analysis was used to determine the key questions.nnnRESULTSnThe mean ( +/- standard deviation) age and body mass index of the adolescents was 14 +/- 1 years and 27.2 +/- 11 kg m- 2. Although 82% of girls and 75% of boys had good nutritional knowledge, only 25% of boys and 15% of girls had good nutritional practice. Eighty-five per cent of adolescents knew that drinking too many soft beverages resulted in overweight or obesity, but only 4.5% of them did not drink soft beverages. Although 89% of adolescents knew that crisps and corn balls are not healthy snacks, 45% of them used such snacks during their break time. Thirty-seven per cent of adolescents preferred whole-grain biscuits to creamy wafer ones but only 10% of adolescents used whole-grain biscuits as a snack. The most frequently consumed snacks among Tehranian adolescents were sausage sandwiches, cocoa cola, crisps and corn balls, creamy wafers, cakes, chocolate and toffee.nnnCONCLUSIONnA low percentage of Tehranian adolescents have good nutritional behaviour and in most of them their nutritional practice does not accord with their nutritional knowledge. These results indicate the necessity of nutritional intervention in Tehranian adolescents.