410 research outputs found

    The role of maternal diet on fetal sex selection: A Review

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    Introduction: The desire of the human to control the gender of fetus prior to conception has always been important. The aim of this study was to determine the role of maternal diet on fetal gender. Materials and Methods: In this narrative review study, a comprehensive review of databases including Pubmed, Scirus, Cochrane library, ScienceDirect, MD Consult, google scholar, Iranmedex, Magiran, and SID from 1982 to 2013 was performed. Key words to search databases included fetal sex, sex ratio, sodium, potassium, magnesium, calcium, fructose, eating disorders, sex selection, maternal diet, Ionic diet, fatty acid, calorie, and famine. Results: Results of studies on the effects of nutritional deficiencies and disorders on sex ratio were controversial. Studies showed that a combination of environmental factors such as stress, time of conception and maternal diet had effects on sex ratio. Preconceptional nutritional status of mothers was very important in changing sex ratio. Increasing the intake of K + + Na+/Ca 2 + + Mg2+ in diet and high calorie diet could increase the ratio of male offsprings. Conclusions: Preconceptional diet was important in fetal sex ratio. However, low sample size in most human studies and the complex mechanisms of sex determination make it difficult to conclude definitively on this issue. Further human studies with larger sample size in this field are suggested

    Performance of FRP-Retrofitted Concrete Bridge Columns Under Blast Loading

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    Contrary to military or essential government buildings, most bridges are designed without any consideration for blast resistance. Fiber-reinforced polymers (FRPs) can provide an effective means for strengthening of critical bridges against such loading. This study has focused on the effectiveness of FRP retrofitting in the dynamic response of reinforced concrete bridge columns under blast loading. Using a simplified equivalent I-section with a virtual material lumped at the two flanges; a lightly meshed uniaxial finite element model was developed and successfully validated against previous studies. The proposed model was then used for a thorough parametric study on the blast resistance of bridge substructures in the form of a single-column, two-column pier frame, and an entire bridge. The study showed the benefits of strengthening with composites against blast loading. The FRP tensile strength and diameter-to-thickness ratio, steel reinforcement ratio, and column length and damping ratio significantly affect the blast resistance of an FRP-retrofitted bridge. Finally, based on the parametric study results, predictive equations with multiple linear regression and high order terms were developed statistically for the FRP retrofit design of single columns against blast loading

    Neonatal thyrotropin concentration and iodine nutrition status of mothers: A systematic review and meta-analysis1

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    Background: Low maternal iodine intake disturbs the thyroid function of neonates transiently or permanently. Objective: To our knowledge, we conducted one of the first systematic reviews and meta-analyses aimed at exploring the association of neonatal thyrotropin concentrations and iodine status of mothers during pregnancy and early postpartum periods. Design: Data were collected through literature searches for studies published between 1969 and 2015 with the use of electronic databases. Mean or median maternal urinary iodine and neonatal thyrotropin concentrations, along with other relevant data, were extracted from eligible studies. The quality and risk of bias of each study was assessed. Results: A random-effects model was used for the analysis. Of 110 studies identified, 25 trials were shown to be eligible for inclusion in the meta-analysis. Mean (95 CI) thyrotropin concentrations of neonates born to mothers with iodine deficiency were higher than in neonates born to mothers with iodine sufficiency during pregnancy in both heel blood samples 1.79 mIU/L (95% CI: 1.61, 1.97 mIU/L) compared with 1.75 mIU/L (95% CI: 1.68, 1.82 mIU/L), respectively and cord blood samples 11.91 mIU/L (95% CI: 6.67, 17.14 mIU/L) compared with 6.15 mIU/L (95% CI: 4.30, 8.01 mIU/L), respectively. There were no significant differences in neonatal thyrotropin concentrations of heel samples between mothers with iodine deficiency and those with sufficiency during the early postpartum period; however, the values of thyrotropin in cord samples of neonates born to mothers with iodine deficiency were significantly higher than in neonates born to mothers with iodine sufficiency 11.62 mIU/L (95% CI: 10.47, 12.77 mIU/L) compared with 7.40 mIU/L (95% CI: 6.21, 8.59 mIU/L). Conclusion: Our findings reveal that, compared with heel blood samples, neonatal thyrotropin in samples collected from the cord are more sensitive to the iodine status of mothers; however, further investigations are required in this regard. © 2016 American Society for Nutrition

    Advanced glycation end products and risk of general and abdominal obesity in Iranian adults: Tehran lipid and glucose study

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    Background: Advanced glycation end products (AGEs) are a heterogeneous group of macromolecules that are formed by the nonenzymatic glycation of proteins, lipids, and nucleic acids. A number of food preparation methods can increase AGEs content. The aim of the present study is to assess the relationship between dietary consumption of AGEs and the risk of obesity and central obesity. Methods: This study was conducted within the framework of the Tehran Lipid and Glucose Study (TLGS) on 4245 subjects who participated in its fifth phase (2011 to 2014). Dietary data were collected using a validated semi-quantitative food frequency questionnaire (FFQ). Participants' characteristics, anthropometric measures, and blood samples were also obtained by trained staff. Multivariable linear regression and Logistic regression was conducted using SPSS (Version 20; Chicago', IL), and P values < 0.05 were considered significant. Results: Our results show that abdominal obesity was increased with higher intakes of dietary AGEs, an association, which remained significant after adjustment for potential confounders (OR=1.56 and 95 CI, 1.16 to 2.84). The relationship between abdominal obesity and dietary AGEs (dAGEs) intake was found to be independent of energy and macronutrient intake. We also found a relationship between consumption of dAGEs and a few anthropometric measurements, such that a significant positive correlation was observed between BMI, WC, BAI and higher quartiles of dAGEs intake, with the correlation being stronger for BAI (β= 0.24 (0.10-0.39)). Conclusion: Our study emphasizes that higher intake of dAGEs does increase the chance of abdominal obesity, and dAGEs might be a link between modern diets and obesity. © Iran University of Medical Sciences

    Long-term effectiveness of a lifestyle intervention on the prevention of type 2 diabetes in a middle-income country

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    This study aims to assess the effects of a community-based lifestyle intervention program on the incidence of type 2 diabetes (T2D). For this purpose, three communities in Tehran were chosen; one community received a face-to-face educational session embedded in a long-term community-wide lifestyle intervention aimed at supporting lifestyle changes. We followed up 9,204 participants (control: 5,739, intervention: 3,465) triennially from 1999 to 2015 (Waves 1&ndash;5). After a median follow-up of 3.5 years (wave 2), the risk of T2D was 30% lower in the intervention community as compared with two control communities by (Hazard-ratio: 0.70 [95% CI 0.53; 0.91]); however, the difference was not statistically significant in the following waves. After a median follow-up of 11.9 years (wave 5), there was a non-significant 6% reduction in the incidence of T2D in the intervention group as compared to the control group (Hazard-ratio: 0.94 [0.81, 1.08]). Moreover, after 11.9 years of follow-up, the intervention significantly improved the diet quality measured by the Dietary Approaches to Stop Hypertension concordance (DASH) score. Mean difference in DASH score in the intervention group versus control group was 0.2 [95% CI 0.1; 0.3]. In conclusion, the intervention prevented T2D by 30% in the short-term (3.5 years) but not long-term; however, effects on improvement of the diet maintained in the long-term.Registration: This study is registered at IRCT, a WHO primary registry (https://irct.ir). The registration date 39 is 2008-10-29 and the IRCT registration number is IRCT138705301058N1

    The association between dietary glycemic and insulin indices with incidence of cardiovascular disease: Tehran lipid and glucose study

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    Background: The present study was conducted to investigate the association of dietary insulin index(II), insulin load(IL), glycemic index(GI), and glycemic load(GL) with the risk of cardiovascular disease(CVD). Methods: This cohort study was conducted within the framework of the Tehran Lipid and Glucose Study on 2198 subjects, aged�19 years old, who were followed-up for a median (IQR) 6.7 (6.1-7.1) years. Dietary GI, GL, II, and IL were calculated using a food frequency questionnaire at the baseline. Multivariate Cox proportional hazard regression models were used to estimate the risk of CVD across quartiles of dietary insulin and glycemic indices. Results: Mean ± SD age of the subjects(44.9 men) was 38.3 ± 13.4 years. During a mean of 2406 ± 417 person-years of follow-up, 76(3.5) new cases of the CVD were ascertained. The mean ± SD of II, IL, GI, and GL of participants were 51.7 ± 6.5, 235.8 ± 90.2, 61.9 ± 7.8, and 202.2 ± 78.1, respectively. After adjusting for the variables of age, sex, smoking, physical activity, daily energy intake, body mass index, diabetes, and hypertension, the hazard ratio (HR) of the highest quartile of dietary GL was 2.77(95CI:1.00-7.69,P for trend:0.033) compared to the lowest one. Also, each one SD increase in the GL score was associated with a higher risk of CVD(RR:1.46;CI:1.00-2.16),P-value = 0.047. However, there was no significant association between the dietary GI, II, and IL and risk for CVD incidence. Conclusions: Our results suggested that a high GL diet can increase the incidence of CVD, whereas high dietary II and IL were not associated with the risk of CVD among adults. © 2020 The Author(s)

    The association of insulinemic potential of diet and lifestyle with the risk of insulin-related disorders: a prospective cohort study among participants of Tehran Lipid and Glucose Study

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    Background: We aim to assess the association of empirical dietary (EDIH) and lifestyle (ELIH) index for hyperinsulinemia with the risk of insulin resistance, hyperinsulinemia, insulin sensitivity, and β-cell dysfunction in Iranian adults. Methods: In this prospective study, a total of 1244 men and women aged � 20 years were selected among participants of the Tehran lipid and glucose study and followed for 3.2 years. Dietary intakes were assessed using a valid semi-quantitative food frequency questionnaire. Dietary and lifestyle insulinemic potential indices were calculated using dietary intake, body mass index, and physical activity information. Multivariable logistic regression was used to estimate the associated risk of a 3-year incidence of insulin-related disorders. Results: The mean ± SD age and BMI of all eligible participants (42.7 males) were 43.0 ± 13.0 and 27.4 ± 4.9 in the study's baseline. After adjusting for all potential confounders, participants in the highest tertile of ELIH score had a greater risk of developing hyperinsulinemia (OR:2.42, 95CI:1.52�3.86, P for trend = < 0.001), insulin resistance (OR:2.71, 95CI:1.75�4.18, P for trend = < 0.001) and insulin insensitivity (OR:2.65, 95CI: 1.72�4.10, P for trend = < 0.001) compared with those in the lowest tertile. However, the risk of incident β-cell dysfunction was lower in individuals with a higher score of ELIH in comparison to those with the lowest score (OR:0.30, 95CI:0.19�0.45, P for trend = < 0.001). Conclusions: Empirical lifestyle index for hyperinsulinemia was directly associated with insulin resistance, insulin insensitivity, and hyperinsulinemia and was inversely associated with β-cells dysfunction. © 2021, The Author(s)

    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

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    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. © 2021, The Author(s)

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

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    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. © 2020 The Author(s)

    Trends of obesity and abdominal obesity in Tehranian adults: a cohort study

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    <p>Abstract</p> <p>Background</p> <p>Considering the increasing trend of obesity reported in current data, this study was conducted to examine trends of obesity and abdominal obesity among Tehranian adults during a median follow-up of 6.6 years.</p> <p>Methods</p> <p>Height and weight of 4402 adults, aged 20 years and over, participants of the Tehran Lipid and Glucose Study (TLGS), were measured in 1999-2001(phase I) and again in 2002-2005(phase II) and 2006-2008 (phase III). Criteria used for obesity and abdominal obesity defined body mass index (BMI) ≥ 30 and waist circumference ≥ 94/80 cm for men/women respectively. Subjects were divided into10-year groups and the prevalence of obesity was compared across sex and age groups.</p> <p>Results</p> <p>The prevalence of obesity was 15.8, 18.6 and 21% in men and 31.5, 37.7 and 38.6% in women in phases I, II and III respectively (p < 0.001). The prevalence of abdominal obesity in men was 36.5, 57.2 and 63.3% and in women was 76.7, 83.8 and 83.6% in the three periods mentioned (p < 0.001). Men aged between 20-29 years had highest increase rates of obesity and abdominal obesity in phase III in comparison with phase I (with a respective rates of 2.2- and 3.3-fold). In both sexes, an increased trend was observed between phases I and II, whereas between phases II and III, this trend was observed in men, but not in women.</p> <p>Conclusion</p> <p>This study demonstrates alarming rises in the prevalences of both obesity and abdominal obesity in both sexes especially in young men, calling for urgent action to educate people in lifestyle modifications.</p
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