[Prevalence and incidence of thyroid dysfunction in individuals aged over 55 years [Tehran thyroid study]]

Introduction: Considering the remarkable increase in life expectancy among older people and lack of data on thyroid diseases in elderly Iranians, this study was designed to determine thyroid dysfunction in people, aged over 55 years

Materials and Method: This study was conducted on 819 Tehranian participants, aged over 55 years from the Tehran Thyroid Study, who were assessed every 3 years for serum free T4 [FT4] and TSH levels and were followed for 10.6 years. Data were analyzed by t test' chi-square test, sig test and cox regression analysis

Results: Mean age of participants was 62.5+/-5.5 years. Of these 712 [86.9%] were euthyroid, 41[5%] had subclinical hypothyroidism [SCH], 19[2.4%] had overt hypothyroidism [OH], 34[4.1%] had subclinical hyperthyroidism and 13[1.5%] overt hyperthyroidism. Overall 13% of participants had thyroid dysfunction. The annual incidence rate of SCH and OH were 8.8 and 7.1 cases per 1000 people respectively. Multivariate regression analysis showed the risk of hypothyroidism in euthyroid people to be affected by TPO positivity [HR=1.9 [CI 95% 1.04-3.5]] and TSH>1.88 mlu/l [HR=8.1 [CI 95% 3.4-19]]

Conclusion: More than one-tenth of aged people have thyroid dysfunction. High TSH and TPO positivity are the most important risk factors of hypothyroidism in elderly people

[Iodine intake knowledge, attitude and practice in pregnant women and its relation to iodine status during pregnancy]

Introduction: Previous research shows that pregnant women, due to their increased need for iodine, are among the high risk groups for iodine deficiency. This study hence aimed to evaluate the status of women's knowledge, attitude and practice [KAP] regarding iodine and iodized salt intake and its association with iodine nutrition levels

Materials and Methods: In this observational analytical study, 100 pregnant women, residents of southern Tehran were randomly selected from five health care centers. Data collected included the general information and demographic characteristics and KAP questionnaires regarding iodized salt intake. Urine assessments of pregnant women and household salt samples were collected and evaluated

Results: Mean age of participants was 27.16 +/- 5.58 years, and their mean +/- SD knowledge, attitude and prachie scores were 62.5 +/- 20.8, 85.2 +/- 12.3, 64.7 +/- 14.3, respectively. Median urinary iodine concentrations and salt iodine content were 25.9[20.6-29.6] ppm and 109[60-160] micro g/L, respectively with 74% of women consuming salt containing 20-40 ppm iodine and 29% had urine iodine concentrations >/= 150 8g/L. Urine iodine concentration was significantly associated with practice score as well as with iodine content of salt

Conclusion: Although women suffered from iodine deficiency, their KAP scores regarding iodine and iodized salt consumption were adequate. Further assessment of other personal and social factors which could affect iodine nutrition status of pregnant women is recommended

incidence of thyroid dysfunctions in patients with type 2 diabetes: a twelve-year follow-up of the Tehran lipid and glucose study

Undiagnosed thyroid dysfunction may impair metabolic control in patients with diabetes. Due to the lack of adequate studies on the incidence of thyroid dysfunction in patients with type 2 diabetes mellitus there is no consensus regarding optimal thyroid screening strategies in routine diabetes care. The aim of this study was to determine the incidence of thyroid dysfunction in patients with type 2 diabetes. In this study, patients aged >/=30 years, participants of in the prospective Tehran Lipid and Glucose Study, who had complete thyroid assessments were divided into two groups of 428 diabetic and 2847 nondiabetic controls and followed for 12 years. The incidence of thyroid dysfunction in these two groups was compared and the relative risk of type 2 diabetes for thyroid dysfunction was calculated. Compared to those without diabetes the disorders patients with diabetes were less likely to develop thyroid dysfunction [incidence rate 12.56 vs. 16.50 cases per 1000 person-years, Relative risk 0.74, 95% Cl, 0.534-1.026, P=0.071]. The incidence of thyroid dysfunction in type 2 diabetic patients is not higher than in non-diabetic individuals, indicating that routine screening of thyroid dysfunctions is not recommended in type 2 diabetic subjects

[Leisure-time physical activity and its association with metabolic risk factors in Tehranian adults: TLGS]

Leisure-time physical activity [LTPA], as a lifestyle-related behavior, could be a preventive factor for metabolic syndrome [MetS]. We aimed to examine the association between LTPA and MetS among the adults who participated in the Tehran Lipid and Glucose Study [TLGS]. In the present cross-sectional study, 4665 adults [1976 males and 2686 females], aged 20-70 years, were selected by multi-stage random cluster sampling from among TLGS participants. Subjects were classified according to their BMI. LTPA was determined via a validated and Modifiable Activity Questionnaire [MAQ], and MetS, according to the JIS criteria. Prevalence of the MetS was higher in obese groups [58.2%] compared to the overweight [36.6%] and normal weight [6%] ones [p<0.001]. Normal weight subjects [18.1%] were physically more active than other groups. In the normal weight group with light LTPA, the risk of lower levels of HDL-C and elevated levels of TG were higher than in individuals with vigorous LTPA [OR: 1.15; CI95% 1.05, 2.33] [OR: 1.46; CI95% 1.01, 2.14]. In the overweight group, the probability of elevated levels of FBS was higher among individuals with moderate LTPA than in those with vigorous LTPA [OR: 1.65 CI95% 1.37, 3.23], and there was also an inverse association between light LTPA and MetS [OR: 2.08; CI95% 1.03, 4.21]. This study confirmed that increased levels of LTPA are associated with a decreased likelihood of any inappropriate changes in components of Mets and the occurrence of Mets

[Goiter and urinary iodine excretion survey of schoolchildren in Qazvin provine: results of 17 years universal salt iodization in Iran [2007]]

The iodine deficiency elimination program, which began two decades ago, has resulted in Iran becoming an Iodine Deficiency Disorders [IDD] free country in the Middle-East region. This study was performed to evaluate the adequacy of iodine supplementation after 17 years of universal salt iodization in the province of Qazvin. In a crosssectional study, 1200 schoolchildren [600 girls and 600 boys], aged 8 to 10 years, were randomly selected from Qazvin province, and evaluated in 2007. Goiter prevalence, urinary iodine excretion and iodine content of household salts were measured and the data obtained were compared with those obtained in 1996 and 2001. Total prevalence of goiter was 0.8%; and no grade 2 goiter was seen. One-tenth of the children enrolled for goiter assessment, were randomly selected for urinary iodine measurement. The median urinary iodine in these 120 schoolchildren was 151 micro g/L, with 4% having urinary iodine excretion less than 50 micro g/L. Sixty-six percent of households were using purified iodized salt, 65% of households had appropriate salt storage, and 30% of the household salts contained less than 15 micro g iodide. Goiter prevalence has significantly decreased in Qazvin province, 17 years after universal salt iodization. Similar to reports from 1996 and 2001, the median urinary iodine of schoolchildren was adequate, indicating a well established sustainable IDD program in Iran

Predicting the metabolic syndrome according to serum total testosterone, free testosterone index and SHBG in males aged over 20 years: Tehran lipid and glucose [TLGS]

In recent years, much attention has been focused on the metabolic syndrome and its association with development of non insulin dependent diabetes mellitus [NIDDM] and cardiovascular disease. Although androgen deficiency in men is associated with obesity, whether the deficiency predisposes to, or is a consequence of the syndrome is still unclear. This study aimed at assessing the association between low levels of total testosterone, the sex hormone binding globulin [SHBG] and free testosterone index, and development of the syndrome, based on ATP III and IDF criteria. We assessed 836 men, aged > 20 years, participants of the Tehran Lipid Glucose Study, at baseline and over 6.5 years follow-up, according to both definitions for occurrence of metabolic syndrome, following adjustment for confounding factors such as age, physical activity, smoking, education, fasting plasma glucose, triglycerides, serum HDL-C, waist circumference, systolic and diastolic hypertension. Using logistic regression models, the association between serum total, free testosterone index and SHBG and metabolic syndrome was investigated. After 6.5 years of follow-up, metabolic syndrome was found to have developed in 131 men and 207 men according to ATP III and IDF criteria respectively. Multiple logistic regression analysis showed an inverse relationship for total testosterone in the lower tertile concentration and serum triglycerides according to both criteria [odds ratio [OR]=1.6; 95% confidence interval [Cl], 1.02-2.5]]. According to ATP III criteria, adjustment of waist circumference eliminated most of the correlations between total testosterone and metabolic syndrome [OR=1.34, 95% Cl [0.8-2.3], while SHBG and free testosterone index were not significantly associated with the syndrome. According to IDF criteria, statistical adjustment of waist circumference eliminated most of the correlations between total testosterone and metabolic syndrome [[OR=1.45, 95% Cl [0.9-2.3]], and adjustment with triglycerides eliminated any correlation between SHBG and metabolic syndrome [OR=1.5, 95% Cl [0.9-2.5]. Our data do not support a predictive or causative role androgen deficiency in the development of metabolic syndrome according to ATP III and IDF definitions but do demonstrate that androgen deficiency may be consequence of the effect of poorly controlled triglycerides and increased waist circumference on, rather that a cause of, poor metabolic status

[Marked reduction in goiter prevalence and eventual normalization of urinary iodine concentrations in Iranian schoolchildren, 10 years after universal salt iodination [third national survey of iodine deficiency disorders 2000]]

Two years after legislation of salt iodization of 40 parts per million [ppm] in 1994, goiter was still endemic and urinary iodine concentration [UIC] remained elevated in many provinces of Iran. Goiter prevalence and UIC were compared two and seven years after sustained consumption of uniformly iodized salt by Iranian households. From December 2000 to June 2001, schoolchildren [7-10 yr] of all provinces were randomly selected by cluster sampling; their goiter rate, UIC, and household salt iodine levels were compared to similar data collected in 1996. Factory salt iodine produced in 2001 was also compared to that of 1996. Ultrasonographically determined thyroid volumes of 7-10 yr old children were compared in 2001 to those of 1999. Total, grade 1, and grade 2 goiters were 13.9 vs. 53.8%, 11.0% vs. 44.8%, and 2.9% vs. 9.0%, in 2001 [n=33600] vs. 1996 [n=36178], respectively [p<0.0001]. Median [range] UIC in 2001 [n=3329] was 165 [18-410] micro g/L and in 1996 [n=2917] was 205 [10-2300] micro g/L [P<0.0001]. Means for iodine salt content were 32.7 +/- 10.1 and 33.0 +/- 10.2 [P=0.79] in households and 33.2 +/- 13.4 and 33.8 +/- 13.2 [P=0.67] in factories, in 2001 and 1996, respectively. Only 7-yr-old children in 2001 [the only group with probably no history of iodine deficiency] showed significantly smaller thyroid volumes compared to those in 1999. After seven years of optimized iodized-salt supplementation in Iran, adequate UIC values and marked reduction in goiter rate have been achieved

[Variation of urinary iodine concentration within a month during the first trimester of pregnancy in Tehran an iodine-repleted area and comparison to non-pregnant women]

In order to assess variations of urinary iodine concentration [UIC] during a 4-week period among pregnant and non-pregnant women in an iodine-replete area. Pregnant and non-pregnant women referred to two maternity hospitals in Tehran were consecutively recruited from September 2005 to March 2006; urine samples [5.10 mL] were collected on an every-other-day basis for 4 weeks [i.e., 12 samples for each individual]. UIC was determined using modified Sandell-Kolthoff method. Thirty-six pregnant and 32 nonpregnant women completed the study. Mean +/- SD age of pregnant women was 27.4 +/- 6.4 and that of non-pregnant women was 27.6 +/- 4.5 years [p=0.897]. Mean +/- SD gestational age was 11.0 +/- 3.3 weeks in pregnant participants. Median UIC of <100, 100-149, 150-249, and .250 ;g/L was present in 19.4, 25.0, 30.6, and 25.0% of pregnant, 15.6, 37.5, 34.4, and 12.5% of non-pregnant, and 17.6, 30.9, 32.4, and 19.1% of total individuals, respectively. Median UIC values of sample, numbers 1 to 12 were not significantly different either in pregnant [p=0.591] or in non-pregnant subjects [p=0.745], except for sample number 11, median UIC was not significantly different between pregnant versus nonpregnant women [P values > 0.05]. Mean SD value for UIC in samples number 1 to 12 in pregnant women was 138.4 [24.1.404], whereas in non-pregnant women this value was118.0 [29.5-272.4]; g/L [p=0.286]. There was a wide intrapersonal variation in UIC values among pregnant and non-pregnant women residing in an iodine-replete area, supporting the notion that casual UIC would not reflect iodine status of the individual