مجله غدد درون ریز و متابولیسم ایران
سال پانزدهم شماره 1 (پیاپی 67، اردیبهشت 1392)

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.

The aim of this study was to estimate the prevalence of obesity and some associated factors among boy students، aged 8 to 12 years in Shiraz. This cross-sectional study was performed on 478 (male) students، 8-12 years old. The subjects were selected via a step wise random sampling. Height and weight of the subjects were measured by standard methods and body mass index (BMI) was calculated. Overweight and obesity were defined based on the 85th and 95th percentiles of BMI for age and sex، respectively، as proposed by Center for Disease Control (CDC). Physical fitness level and family conditions were collected by a standard Baecke questionnaire. The prevalence of obesity، overweight and underweight in 8-12 year old students were 7. 1%، 11. 9% and 14. 8% respectively. Results showed that there were inverse relationships between BMI and age and the parent''s education (P<0. 05). On the other hand، although BMI had positive associations with the time spent watching TV، fast food consumption، time spent on exercise and walking during a week، they were not achieve statistically significant. The lower the level of parent''s education، the more the increase in student''s BMI، findings which emphasize the need for awareness about childhood obesity complications among parents.

Iodine deficiency disorders (IDD) have been recognized as a major public health problem in Iran for many years. Following the iodine deficiency elimination program، Iran is now an IDD free country in the Middle-East region. This study was performed to evaluate the adequacy of iodine supplementation after 18 years of universal salt iodization and the current status of iodine nutrition in all 30 provinces of Iran. In this descriptive cross-sectional study، (conducted between Oct 2007-February 2008) 36000 schoolchildren، aged 8 to10 years، were randomly selected from all provinces. Goiter prevalence and urinary iodine excretion in schoolchildren and iodine content of salt at household، factory and distribution sites were measured. Total goiter rate (TGR) in the country was 6. 5% (6% grade 1 and 0. 5% grade 2)، and weighted goiter rate was 5. 7%. TGR in Hamedan، Zanjan، Kermanshah، Mazandaran and Gilan was over 10%. The median urinary iodine was 140µg/L، with urinary iodine levels of 20-50، 50-99 and ≥100μg/L being 15. 3%، 19. 8% and 64. 9%، respectively. In four provinces، median urinary iodine was lower than100 µg/L. Mean (±SD) and median salt iodine were 23. 2 (±13. 8) and 34. 7ppm at production level and 32. 4 (±14. 7) and 32. 3ppm at distribution level، respectively. Ninety-eight percent of households consumed iodized salt، and 58% of households had appropriate salt storage. The I. R. Iran has made strong progress in the development of universal salt iodization strategy and meets all criteria for sustainable elimination of iodine deficiency. However، lack of adequate iodine nutrition in some provinces necessitates special attention and proper monitoring.

Quantile regression can be applied to model skewed variables، especially، when the objective is to model the tails of a response variable with highly skewed distribution. The aim of this study is to apply quantile regression to analyze urine iodine data and related factors in a Tehranian population. Data was collected in a cross-sectional study، in which 639 subjects، aged 19 years and over، were enrolled through randomized cluster sampling in Tehran between 2008-9. Due to the high skewness of 24hr urinary iodine concentrations (UIC24) and to evaluate its extreme points، two linear quantile regression models were fitted. In model I، UIC24 was regressed on iodine content of salt and daily salt intake. These variables were replaced by iodine intake in model II، both models were adjusted by age. Model coefficients were estimated using the linear programming method and simplex algorithm. Significancy of the variables were evaluated by the bootstrap method. The Akaike information criterion (AIC) was used to assess the fitting of the models. All analyses were performed using R software version 2. 12. 2. Model I showed an increase in coefficients of iodine content of salt، daily salt intake، but a decrease in age coefficient in the length of the urinary iodine concentration percentiles. Model II showed similar results، but better fit (smaller AIC) in percentiles lower than median. Compared to ordinary regression، quantile regression models showed better fit، and a more complete picture and are recommended for modeling all parts of UIC24.

The first occurrence of menstruation (or periods) is called menarche and it is a vital event during puberty in girls. Various studies show a downward trend in menarcheal age over the last hundred years. Many factors can influence age at menarche. The aim of this study was to determine the correlation between menarcheal age and certain demographic characteristics، in female residents of district 13، Tehran Lipid and Glucose Study. In this longitudinal descriptive، conducted within the framework of the Tehran lipid and glucose study، subjects were 402 girls، aged 12 and 18 years، whose menarche had not begun at the initiation of the study، but it did during their follow-up. In order to collect data، questionnaires previously completed in the TLGS were used. Validity and reliability of the questionnaire confirmed in previous studies. Various factors including maternal age at menarche، maternal education، maternal occupation، body mass index، physical activity، energy expenditure and exposure to tobacco smoke were examined. Findings showed that the mean age at menarche was 13. 06 ± 1. 24 years in this study. There were significant statistical associations between body mass index (P=0. 002، r=-0. 04)، mother''s age at menarche (P<0. 001، r=0. 66) and maternal education (P=0. 027، r=0. 25) and the subjects age at menarche. However there was no significant association between age at menarche، with mother''s occupation، passive smoking، physical activity and energy expenditure. It seems that BMI، mother’s menarcheal age and maternal education are factors that influence the age at menarche.

Lipid abnormalities are a major cause of cardiovascular diseases in patients with type 2 diabetes. The present study was therefore designed to investigate the supplemental effects of grape seed extract on serum lipid profiles of patients with type 2 diabetes.

The study was a randomized، triple-blind، clinical trial in which 48 patients with type 2 diabetes were randomly assigned to 2 groups، the grape seed extract supplement and the placebo group. The patients in the grape seed extract group received 200 mg/d grape seed extract for 8 weeks while the placebo group received a corresponding placebo. At baseline and or the end of the 8th week of the study، 5 ml blood was collected after a 12 to 14-hour fast from each patient and serum triglycerides، total cholesterol، HDL-C، and LDL-C were measured.

There were no significant differences between the two groups with regard to mean changes of serum trigl ycerides، total cholesterol، HDL-C، and LDL-C.

The results of the present study indicate that grape seed extract supplement has no effect on serum lipid profiles in patients with type 2 diabetes.

The aim of this study was compare the effects of fasting during Ramadan (as a dietary pattern) and regular aerobic exercise on HSP70، lipid profile and insulin resistance indexes in non-active obese men. In this study، 18 obese men، aged between 50-40 years، with a BMI over 30 kg/m2 per square meter were randomly selected from among 70 volunteers responding to a public call. They were then divided into two، the fasting (N=9) and the fasting with exercise (N=9) groups. While the first group just fasted، the fasting and exercise group in addition to fasting performed 27 sessions of exercise at an intensity of 50–70 % of their VO2max،. Also، to study the desired changes in Ramadan، blood samples were taken at four different times points and finally، using repeated measures analysis of variance at the significance level of p<0. 05، data was analyzed. Results showed that Hsp70 levels in both groups increased during Ramadan. Also، HSP70 levels in both the fasting and the fasting with exercise groups increased، during the fourth week of Ramadan، the difference between the groups being significant (F =23/25; p= 0/001). Insulin resistance also decreased in both groups، a reduction that was significant in the fasting group (F =3. 244; p= 0. 042). Additionally، only in the fourth week of Ramadan and two weeks after that the lipid profile of the participants decreased and their HDL-C increased، changes all significant (p<0. 05). The research results show that the increased levels of HSP70 as a result of fasting perse، and fasting with exercise، may lead to decreased insulin resistance in obese men.

The present study aims to investigate the effects of exhaustive running and different doses of short-term garlic supplementation on total antioxidant capacity (TAC) and Malondialdehyde (MDA) in during rest and exercise induced exhaustion in male soccer players. Thirty male football players (Average age: 20. 8±1. 45y; maximum oxygen intake 67. 2±5. 4 ml/kg/min and body mass index 21. 5±1. 34 kg/m2) were divided randomly into three homogenous groups، the placebo group and the 2 garlic supplementation groups given two dosages (1200 and 2400 mg/day). The first and second blood samples were taken in the basic state and after the Shuttle Run test and the third and fourth samples were taken after supplementation، in the basic state and after test. The parameters were then analyzed using one-way ANOVA، with a significance level of a=0. 05. Exhaustive running significantly decreased TAC and increased MDA level in the blood serum of male football players. On the other hand، garlic supplementation increased TAC (P<0. 01) and decreased MDA (P<0. 01) in the basic state. Moreover، supplementation hindered significant increase in the level of MDA (P<0. 05) in male football players after the test but it failed to stop the decrease in TAC (P<0. 05) level. Furthermore، the decrease of TAC level in suppleme ntation group was significantly (P<0. 05) less than in the placebo group. Short-term garlic extract supplementation may increase TAC and MDA in male football players in the basic state and hinder the fall in the total antioxidant capacity and oxidative stress after vigorous exercises. On the other hand، neither dosages of 1200 nor 2400 mg/day of garlic extract showed any effects on TAC or MDA in the groups of players investigated.

CD36 is a key protein involved in regulating the uptake and utilization of fatty-acids in heart and skeletal muscle. The aim of this study is to assess the association between rs10499859 A>G and rs13246513 C>T polymorphisms of CD36 gene and metabolic syndrome (MetS). In this case-control study، 140 subjects with MetS and 187 healthy ones were randomly selected from among the Tehran Lipid and Glucose Study population. Biochemical and anthropometrical variables were measured، and polymorphisms were examined by polymerase chain reaction-restriction fragment length polymorphism. Case and control groups did not differ in allele and genotype frequencies for these SNPs. Under a dominant model، A and T alleles of these SNPs were significantly associated with elevated levels of HDL-C، before age and sex adjustment (P 0. 027 and 0. 016 respectively). A allele carriers had significantly increased levels of BMI compared to G allele carriers after adjustment for MetS، and under the dominant model (P= 0. 009). Presence of G allele was also significantly associated with increased diastolic blood pressure (P= 0. 016) before adjustment for confounders، using a recessive model. The results of this study show that genetic variation of CD36 gene was associated with metabolic risk factors such as HDL-C and BMI. Although the effect of each SNP polymorphism plays a small role، it depends specifically on their interaction with environmental factors.

Sesame seeds contain large amounts of antioxidants and phytoestrogens، and it has been shown that the leaf extract of this plant may have some beneficial effects on the reproductive parameters of male rats. Thus we tested the effects of the sesame oil on these parameters of reproductivity in male rats.

Fifteen mature male Wistar male rats were divided into the control and sesame oil groups. For eight weeks the control and sesame oil groups were fed the basic rat diet and basic rat diet supplemented with 5% sesame oil respectively. Following blood collection and euthanasia the epididymal sperm were counted، the morphology of testes was accessed، and leydig، sertoli، spermatogonia and spermatocyts cells were counted in histological sections of the testes. The level of testosterone and estradiol 17- β were measured.

Consumption of 5% sesame oil compared to control group، decreased blood glucose and increased the epididymal sperm count and progressive motility and the number of spermatogonia of seminiferous tubule (P<0. 05)، but had no effect on weight and testicular morphology.

This study showed that the sesame oil consumption improves some reproductive parameters، which may be related to the antioxidative and phytostrogenic properties of the sesame oil or insulin action improvement.

Acute and chronic hypoxia influence blood glucose levels and decrease body weight. Ghrelin increases appetite and body weight and regulates energy metabolism and also glucose homeostasis. Therefore، in the present study the effects of ghrelin administration on blood glucose، body weight، food intake and hematocrit were investigated in a model of systemic normobaric acute and chronic hypoxia in adult male rats. Forty-eight adult male Wistar rats were divided into six groups [acute control + saline، chronic control + saline، acute or chronic hypoxia + saline، acute or chronic hypoxia + ghrelin (80 µg/kg/day، ip)]. Control groups remained in room air (21% O2) and hypoxia (11% O2) induced by a normobaric hypoxic chamber for two days (acute) or ten days (chronic). Blood glucose levels، body weight، food intake and hematocrit were assessed. Chronic hypoxia caused a significant (P<0. 001) decrease in blood glucose levels. Administration of ghrelin increased blood glucose levels significantly in acute (P<0. 05) and chronic (P<0. 01) hypoxia. Body weight decreased (P<0. 001) in both acute and chronic hypoxic groups. Administration of ghrelin could (P<0. 001) prevent decrease in body weight in chronic hypoxia group. Acute and chronic (P<0. 001) hypoxia significantly decreased food intake. Ghrelin however increased food intake in both the acute (P<0. 001) and chronic (P<0. 05) hypoxia groups. Acute (P<0. 01) and chronic (P<0. 001) hypoxia also increased hematocrit. Ghrelin administration is useful in modulating blood glucose، body weight and food intake in hypoxic situations.