مجله غدد درون ریز و متابولیسم ایران
سال ششم شماره 1 (پیاپی 21، بهار 1383)

The incidence of permanent and transient CH has not yet been determined in Iran. This report illustrates the incidence of permanent and transient CH in Tehran and Damavand. From February 1998 to August 2002, cord dried blood spot samples in Tehran and Damavand were collected and those with TSH 20 mU/L were recalled (two-site IRMA). Between 7-14 days of life or thereafter, CH was confirmed by serum TSH >10 mU/L and T4 <6.5 g/dL or TSH >30 mU/L alone and L-T4 was immediately started. CH-affected newborns were followed-up until May 2003. Dysgenesis was determined using 99mTC thyroid scanning and /or ultrasonography. In thyroid eutopic newborns, dyshormonogenesis was diagnosed by a 4-week discontinuation of L-T4 between 2-3 years of age and abnormal serum TSH and T4 values, while normal levels after discontinuation confirmed transient CH. Cases with incomplete early follow-ups without thyroid imaging, were known as unknown CH. Of 35067 screened neonates 373 had cord TSH 20 mU/L and were recalled (recall rate: 1.06%). 35 had CH (incidence of 1:1002 births), 25 had permanent CH (incidence of 1:1403 births), and 6 had transient CH (incidence of 1:5845 births). The type of CH remained unknown in 4 cases. Thyroid dysgenesis and dyshormonogenesis were detected in 18 (incidence of 1:1948 births) and 7 cases (incidence of 1:5010 births), respectively. The high incidence of permanent CH underlines the necessity to implement a national CH screening program in Iran.

Hypothyroidism is one of the preventable causes of mental retardation, which according to its clinical manifestations within the neonatal period, can be diagnosed in only fewer than 10% of cases. Delayed diagnosis results in irreversible cerebro-auditory complications unless the problem is diagnosed by screening programs.

From May to December 2002, T4 and TSH concentrations of 20,000 serum samples obtained from newborns on 3rd-7th day of birth, born in seventeen hospitals throughout Isfahan were measured by RIA and IRMA, respectively. The newborns with abnormal screening results (TSH> 20 mIU/L, T4<6.5 μg/dL and based on the weight) were re-examined. Newborns with TSH >10mIU/L and T4<6.5 μg/dL on the second measurement were considered to be hypothyroid so treatment was begun. After performing complementary tests, the hypothyroid patients received replacement therapy with levothyroxine.

From 20,000 neonates that were examined, 531 were recalled (Recall rate = 2.65%) and 54 newborns were diagnosed as hypothyroid. The prevalence of neonatal hypothyroidism was estimated to be 1/370.

Considering the high prevalence of the disease in the population, the necessity of routine neonatal screening programs is underscored.

Congenital hypothyroidism (CH) is one of the most common preventable causes of mental retardation in newborns. In this study, we investigated the incidence of CH in Rafsanjan. From all neonates born from 22 Dec 2001 to 22 Apr 2002, heel blood samples on filter paper were collected and TSH values were assayed using ELISA method and TSH 20 mIU/L was considered abnormal and recalled. Upon recall, the diagnosis of CH was confirmed according to abnormal serum TSH levels using age-adjusted reference values for thyrotropin. TSH < 3.98 mIU/L was considered normal according to the manufacturer's instructions. The association between heel-blood TSH values and of birth weight and height, sex, maternal age, gestational age, delivery mode, maternal occupational status, parental educational level, thyroid disorders in family, and iodized salt consumption were assessed. Of 950 neonates (480 girls and 470 boys), 230 (24.2%) had TSH 20 mIU/L. TSH levels were between 20-49.9 and  50 mIU/L in 206 and 24 neonates, respectively. Of total recalled neonates, only 152 came for serum confirmatory tests between 1-4 months of age. Nine cases had serum TSH  3.98 mIU/L but none of them had enough elevated TSH values to confirm the diagnosis of CH. The only neonate with heel-blood TSH of 137 mIU/L was inaccessible and the CH diagnosis remained unclear. No association was found between heel-blood and serum TSH and of the variables mentioned above. The incidence of CH in Rafsanjan remains unclear however, the recall rate was extremely high. The latter is not only suggestive of a high prevalence of CH, but also of some etiologic factors affecting the rate of hyperthyrotropinemia in Rafsanjan.

To study the effects of levothyroxine (LT4) administration on several diagnostic indices in patients with subclinical hypothyroidism. Twenty-seven patients (19 female and 8 male), mean age: 38±13.5 years (range: 17-61) with basal serum TSH levels of 5.0-16.3 mU/L (mean: 8.4±5.2) and normal FT4I were enrolled. Patients were matched and randomly allocated into two treatment groups, LT4 and placebo. In the LT4 group, dosage was titrated to achieve a serum TSH level between 0.3-3.5 mU/L (mean dose, 75±3.8 μg/day). Main outcome measures were: clinical scores, psychomotor tests and serum concentration of thyroid antibodies, lipids, apolipoproteins A and B, paraoxonase, prolactin, sex hormone binding globulin, CPK, calcium, phosphorus, alkaline phosphatase and sodium before and after treatment. Patients had follow-up visits for 11-14 months (mean: 12±0.6). Ten patients in the LT4 group and 13 in the placebo group completed the study. Mean TSH levels changed from 9.5±6.1 to 1.3±1.2 mU/L (p<0.002) and 7.5±3.1 to 18±15.8 mU/L (p<0.002) in the LT4 and placebo groups, respectively. Eleven patients in LT4 group and 9 in the placebo group had goiter at the beginning of study. At final follow-up visit, goiter size increased in 3 patients in the placebo group and decreased in 4 patients in the LT4 group (p<0.05). Mean total cholesterol, LDL-cholesterol, lipoprotein (a) (p<0.045) and SHBG (p<0.001) increased significantly in the placebo group, but did not change in the LT4 group. Clinical hypothyroidism developed in one patient in the placebo group. Other parameters including clinical scores and psychomotor tests were unchanged in both groups. One year after follow-up, significant increase in serum lipids and TSH levels and goiter size were observed in the placebo group. This warrants further attention to patients with subclinical hypothyroidism.

Dual X ray absorptiometry (DXA) is the preferred method for bone mineral density (BMD) studies. Quantitative ultrasonography (QUS), however, has advantages in that it is less expensive, portable and does not expose the individual to radiation. These advantages have suggested a role for QUS in screening studies. In this study, we tried to determine cutoff values for this method. 420 menopausal women were recruited. BMD values were determined with both QUS and DXA methods. T scores were calculated and the relation between the two T-scores measured in each participants were assessed. The agreement between the two T-scores calculated by the QUS and DXA was assessed by Kappa test in lumbar and femoral neck regions. Kappa scores as measure of agreement between T-scores measured by QUS and DXA, were 0.31 for lumbar region and 0.5 for femoral neck region. Score -1 was determined as the cutoff point for calcaneus bone QUS studies. Determination of a cutoff point for QUS, obviates performing unnecessary DXA and provide the opportunity for large scale studies. Keywords:

Diabetes mellitus seems to be the final stage of metabolic syndrome. The purpose of this study was to determine the importance of metabolic syndrome and its components in development of diabetes. In Tehran Lipid and Glucose Study, 3995 people above the age of 20 (2353 females), were followed up for 1 to 4 years till December 2003. In this cohort study, metabolic syndrome at the beginning of the follow-up was defined, according to NCEP criteria, by the presence of three or more of the following components: abdominal obesity, hypertriglyceridemia, low HDL-C, high blood pressure, and high fasting glucose (above 110 mg/dL). Diabetes was defined as a fasting blood glucose above 126 or 2-hour post glucose load above 200 mg/dL, or use of hypoglycemic medication. The incidence of diabetes after follow up was compared between those with non-diabetic metabolic syndrome at the beginning of the study and healthy controls. Chi-square test and logistic regression along with ROC analysis were used. The mean follow-up interval was 3.2 years. 117 non-diabetic individuals developed diabetes in this period which means an incidence risk of 4%. The incidence of diabetes in individuals with metabolic syndrome was more than in normal subjects (8% vs. 2.3%, P<0.001). The chances of developing diabetes after this period were higher in non-diabetics with metabolic syndrome than in normal subjects (OR=3.1 95%CI: 2.1-4.6). Multivariate logistic regression showed that high FPG below diabetic range (OR=11.4, 95%CI: 7.0-18.63), abdominal obesity (OR=2.1 95%CI: 1.4-3.1) and hypertension (OR=2.0 95%CI: 1.4-3.0) at the beginning of the study, were independent risk factors for developing diabetes after 3.2 years. The risk of developing IGT and IFG in normal individuals was also related to all components of the metabolic syndrome. Non-diabetic patients with metabolic syndrome have a greater chance of developing diabetes mellitus and milder forms of glucose metabolism disorders, and those with high plasma glucose, hypertension and abdominal obesity are at greater risk.

Cardiovascular disease is one of the most common chronic diseases in the world. Blood cholesterol, the most important predictor of heart attacks, may increase through childhood and its level in this period is correlated with that in adulthood. This study aimed to assess blood lipid profile and its relationship to dietary intake and socio-economic factors in high school adolescent girls in Tabriz. 232 female high school students were selected through stratified random sampling in the city of Tabriz. Demographic and socio-economic status were collected using a self-administered questionnaire and dietary intake data was obtained using a 24-hour recall and two day diet records. From each subject, a 4cc sample of fasting venous blood was drawn. Serum lipids were measured by enzymatic method. Height and weight were measured and BMI was calculated. Mean±standard deviation of triglycerides, total cholesterol, LDL-C and HDL-C were 94.99±42.5, 158.07±42.74, 103.45±40.95 and 36.23±10.51 mg/dL, respectively. Prevalence of hypertriglyceridemia (TG≥200 mg/dL) in these samples was low (less than 3 percent), while hypercholesterolemia (TC≥200 mg/dL), high LDL-C (LDL-C≥130 mg/dL), and low HDL-C (HDL-C≤35 mg/dL) were seen in 16.4%, 21.1% and 54.7%, respectively. No associations were observed between dietary intake, socio-economic status and serum lipid levels in the samples. However, a significant correlation was observed between BMI and TG (r= 0.23, P= 0.01), TC (r= 0.29, P= 0.01) and LDL-C (r= 0.22, P= 0.01). High prevalence of overweight and hyperlipidemia in the studied adolescents, emphasizes the need for monitoring and intervention to decrease and control serum lipids in this group. Body mass index is the most important factor that correlates with increase in blood lipids in the studied sample.

The purpose of this study was to describe blood pressure values in Iranian adults with ECG evidence of a myocardial infarction. High blood pressure is a risk factor and ECG can be diagnostic of coronary artery disease. In recent studies, the role of pulse pressure in predicting coronary artery disease has been suggested to be more important than that of blood pressure. From among participants of Tehran Lipid and Glucose study, data for 2479 men and 3060 women aged ≥30 years, not currently using any antihypertensive medication, were collected. The study used the mean of two separate blood pressure measurements for each individual. ECG findings of all subjects were coded according to Minnesota ECG coding criteria and they were categorized into 1) probable/possible myocardial infarction or 2) no myocardial infarction. ECG evidence of probable or possible MI was found in 1.2% of subjects (1.8% in men vs. 0.8% in women, p<0.001). Prevalence of ECG-defined MI in hypertensive cases was two-fold higher than in normotensives. Adjusted for age, sex, and body mass index, mean diastolic blood pressure was significantly lower in cases with ECG-defined MI than in subjects without MI (73 vs. 75 mmHg, p<0.03). There was no significant difference between pulse pressure and systolic blood pressure in all subgroups. In both normotensive/hypertensive and MI/no MI subgroups, pulse pressure was more strongly correlated with systolic rather than diastolic blood pressure. Pulse pressure, as a risk factor for cardiovascular disease, is better predicted by systolic blood pressure than diastolic blood pressure in both normotensive and hypertensive populations with or without ECG-defined MI.

Diabetes is one of the most common endocrine diseases. With regard to the importance of blood glucose regulation in prevention of diabetic complications, glycemic and insulinemic response determination of foods containing carbohydrates is greatly important. The purpose of the present study, therefore, was to determine the effect of low glycemic index foods taken at dinner on fasting blood glucose and subsequent breakfast glycemic and insulinemic responses in patients with type 2 diabetes. The study was a randomized, cross-over clinical trial in which 8 diabetic patients (4 male and 4 female), were randomly allocated to one of the following two diet regimens: 1) Dinner with high glycemic foods: Potato puree, egg white, \"Lavash\" bread, and oil. 2) Dinner with low glycemic foods: cooked lentils, \"Sangak\" bread, and oil. The following day, fasting venous blood samples were collected, then the two groups received standard breakfast which included toast bread, cheese, and tea. Venous blood samples were collected at 60, 120 and 180 minutes following breakfast. Serum glucose was measured by enzymatic methods (glucose oxidase) and serum insulin by ELISA. The washout period was 7 days and then the order of the study was reversed. The data were statistically analyzed by paired t- test. Characteristics of the patients were as follows: age 60.25±10.3 years, duration of diabetes 11.5±3.5 years, body mass index 27.123 kg/m² and fasting blood glucose 159.3837.5 mg/dL. Fasting blood glucose differences with postprandial breakfast levels were significantly lower in low glycemic group than the high glycemic group at 120 (277.9± 67.2 vs. 226.7±54.8 mg/dL, p<0.03) and 180 minutes (229.5±75.3 vs. 159.8± 57.7 mg/dL, p<0.05). The post-breakfast IUAC (area under incremental curve) for glucose was lower after consumption of low glycemic foods (21187.5±6607.9 vs. 13605±1979.9 mg.min/dL, p<0.01). 3) Differences between serum insulin levels at zero, 60, 120 and 180 minutes after starting breakfast with the fasting level were similar in the two groups. The post-breakfast IUAC for insulin was similar in the two groups. It is concluded that the use of low glycemic foods at dinner can decrease fasting glucose and insulin levels, as well as glycemic and insulinemic responses after breakfast in patients with type 2 diabetes mellitus. This can possibly have a great role in regulating blood glucose in these patients.