Iranian Journal of Endocrinology & Metabolism
Year:2005 | Volume:7 | Issue:SUPPLEMENT 4|Papers Count:14

Introduction: The aim of this study was to examine the relation between CETP activity and TaqI and -629A/C polymorphism and its effect on HDL-C level. Materials and Methods: 335 people from the Tehran Lipid and Glucose Study were selected with the lowest, medium and highest deciles of HDL cholesterol levels. Genomic DNA samples were extracted and in the CETP gene a segment of the promoter and a segment of intron 1 were amplified and then incubated with restriction enzymes, Van19 I and TaqI respectively using the RFLP method. 103 homozygote subjects were selected for measurement of CETP activity. Results: The B2 and A allele presence was significantly associated with increased levels of HDL-C and decrease of CETP activity. (B1B1, 67.8±8.9 pmol/L; B2B2, 62.6±9.6 pmol/L; P 0.010) (CC, 68.6±8.4 pmol/L; AA, 62.7±9.7pmol/L; P 0.002)]. Conclusion: We demonstrated that the B2 allele presence in TaqI polymorphism is associated with low CETP activity and high HDL-C; similar results can be seen in presence of the A allele in –629A/C polymorphism.

Introduction: The b3-Adenoceptor (ADRB3) is one of the genes, which play a role in the regulation of lipid metabolism, especially in obesity. In the other studies a common ADRB3 polymorphism (Trp64Arg) shows the association to obesity. In this study we want to examine this finding in an Iranian population. Materials and Methods: Subjects were selected from the Tehran Lipid and Glucose Study in four groups according to their body mass index: BMI<20, 20£BMI<25, 25£BMI<30, BMI³30 and finally 431 (211 men and 220 women) subjects were randomly selected for each group. We measured FBS, HDL-C, triglyceride and cholesterol level and accounted for factors that are known to influence on obesity, such as smoking, body mass index, Ideal body weight and blood pressure. We amplified a segment of the mentioned gene with PCR and then revealed the polymorphism with RFLP (BSTN1).Results: The A allele frequency was 0.08 among the population and its presence was significantly associated with increase of BMI (AA/TA, 27±5.6 kg/m2; TT, 25.4±5.5 kg/m2; P:0.041) and other related factors such as FBS, triglyceride and cholesterol levels and the decrease of the ideal body weight. Conclusion: These data demonstrate that the (Trp64Arg) variation at the b3-Adenoceptor gene locus has an association with increase of body mass index and decrease of ideal body weight in this population.

Introduction: The aim of this study was to calculate the Hardy-Weinberg equilibrium in the TaqI and –629A/C polymorphisms in the CETP gene and analysis linkage disequilibrium in B2 and A allele. Materials and methods: 335 participants of the Tehran Lipid and Glucose Study were selected with the lowest, medium and highest deciles of HDL cholesterol levels. Genomic DNA were extracted and in the CETP gene a segment of the promoter and a segment of intron 1 were amplified and then incubated with restriction enzymes, Van19 I and TaqI respectively using the RFLP method. Results: The B2 allele frequency of the TaqI polymorphism was 0.382 and A allele of the -629A/C polymorphism was 0.462. The linkage analysis showed D=0.0965 and D′=0.4695. Conclusion: We demonstrated that B1 and B2 allele frequency in intron1, and A and C allele frequency in promoter of the mentioned gene was in disequilibrium in our population and that linkage disequilibrium was seen between A and B2 allele.

Introduction: To determine the factors influencing the value of 2 hour plasma glucose (2h-PG) during oral glucose challenge test (OGTT) and to determine factors predicting isolated postchallenge hyperglycemia [(IPH) (FPG < 126 mg/dL and 2h-PG ³200 mg/dL)] in a population based study. Materials and Methods: From 15,005 participants the Tehran lipid and glucose study (TLGS),we evaluated data and result of OGTT in 5,386 individuals (2,909 women and 2,437 men) aged ³20 years, free of known diabetes and other disorders influencing glucose metabolism. Multiple linear and a logistic regression models were developed to predict the value of 2h-PG and IPH respectively. Results: The multiple linear regression model showed six explanatory factors (FPG, age, sex, TG, SBP, waist) to be positively correlated with 2h-PG. The model could predict 47.7% of total variance of 2h-PG. The percent contributions of the above mentioned variables were 41.7, 2.2, 1.7, 1.2, 0.7 and 0.2, respectively. The overall prevalences of non-diabetic subjects, IPH and undiagnosed type 2 DM (FPG³126 mg/dL) were 94.5% (n=5,088), 2.5% (n=133) and 3.1% (n=165) respectively. The odds ratios for presence of IPH were statistically significant for each 5 mg/dl increment of FPG (OR=1.95; 95% CI: 1.8-2.1), age ³40 years (OR=2.0; 95% CI: 1.3-3.2), abnormal waist (OR=2.1, 95% CI: 1.4-3.1) and abnormal TG (OR=2.0; 95% CI: 1.3-3.1). Conclusion: Age, sex, TG, SBP and waist after FPG are the best predictors of 2h-PG. Considering the logistic analysis, OGTT can be recommended in subjects with FPG <126 mg/dL in the presence of abnormal waist circumference and TG, age ³40 and especially when FPG reaches values close to 126 mg/dL.

Introduction: The relative importance of central obesity variables for prediction of type 2 diabetes risk in different populations is still debated. Our aim was to compare the ability of waist circumference (WC), waist-to-hip ratio (WHR) and waist-to-height ratio (WHtR) to body mass index (BMI) to predict incident diabetes in an urban adult population of Iranian men. Materials and Methods: This is a population-based longitudinal study with a mean follow-up duration of 3.6 years. Demographic data were collected; anthropometric variables and blood pressure were measured according to standard protocol in a representative sample of 1852 males aged ³20 years, participants of the Tehran Lipid and Glucose Study. Biochemical measurements including serum lipids and glucose were done. According to ADA criteria, those with fasting blood glucose ≥ 126 mg/dL or blood glucose ³200 mg/dL, 2 hours after 75 g oral glucose tolerance test were considered diabetic. Logistic regression models with stepwise conditional method were used to estimate the relative risk of developing diabetes associated with anthropometric variables before and after glucose tolerance adjustment. Receiver operating characteristic (ROC) curves were used to determine the diabetes predictive power of each model.Results: The odds ratios of developing diabetes associated with WHtR, WC, WHR and BMI, after adjustment of glucose tolerance were 4.6, 3.0, 2.5 and 1.7, respectively. There was a decrease in the statistical power of diabetes prediction of each anthropometric variable after adjustment for glucose tolerance. Among central obesity variables only WHtR had significantly higher ROC area than BMI (0.716 vs. 0.693, P<0.05). WHtR also continued to be the best predictive central obesity variable compared to BMI, even when analysis was restricted to subjects with BMI< 27kg/m2, whereas none of the central obesity variables proved to be superior than BMI in subjects with BMI³27kg/m2. Conclusion: The findings of this study showed WHtR as the best single central obesity variable in addition to BMI, to be used in identifying potential male diabetics.

Introduction: Appropriate diabetes management by insulin administration is mainly based on clinical judgment and is usually achieved through a relatively time consuming trial and error process. Artificial neural networks may offer a useful opportunity for prediction of final controlling insulin dosage and hence, faster achievement of good control among hospitalized and poorly controlled diabetics. Materials and Methods: To design such a system, we first prepared a list of variables probably affecting appropriate insulin dosage. We designed a 3 layer feedforward artificial neural network with backpropagation as the training algorithm using MatLab 6.0. The system was trained and the convergence was achieved using 150 cases. Thereafter the capability of the neural network to predict the final controlling total insulin doses was tested on 50 cases. Results: In 74% of tested cases, the trained system could predict total insulin dose within ±5% of actual controlling dose. Conclusion: This study indicates that artificial neural networks may assist medical experts to achieve optimal and/or acceptable blood glucose level more rapidly among hospitalized diabetic patients.

Introduction: The long-term effect of the subclinical form of postpartum thyroid dysfunction (PPTD) has not been well established. This study was conducted to evaluate the outcome of permanent hypothyroidism in a large cohort of women with PPTD. Materials and Methods: Of 213 women with PPTD, 172 (81%) returned for follow-up. There were 27 (16%) with subclinical (group 1) and 145 (84%) with overt hypothyroidism (group 2). They were all treated with levothyroxine for 23±16 months and followed-up for thyroid function after thyroxine (T(4)) withdrawal. Results: In group 1, the time of occurrence of PPTD was longer, serum was higher and TSH was lower than in group 2. After T(4) withdrawal, 59 and 64% of patients became hypothyroid in groups 1 and 2 respectively; however, serum TSH was increased in group 2 as compared with group 1 (29.7±8.4 vs 16.4±15.4 mU/l, P<0.002). The duration of euthyroidism, serum free T4 and triiodothyronine indices and thyroperoxidase antibodies were not significantly different between the two groups. Conclusion: It was concluded that a high percentage of patients with the subclinical form of PPTD proceed to permanent thyroid failure. The timely recognition of mild to severe cases of PPTD is important for the improvement of life for mothers and infants.

Introduction: Increasing interest to study the effect of nitric oxide (NO) arise the need to establish a rapid and simple method for its determination. Nitric oxide has a short half life, and as a result its direct determination is difficult; hence measurement of its metabolites (nitrite and nitrate) is preferred. This assay provides a good estimation of NO output in vivo. Although NOx determination with Greiss reaction has a long history but for determination of NOx in large numbers of samples, development, evaluation and validation of a simple, rapid and non expensive microplate format method was the aim of this study.Materials and Methods: For this purpose, nitrate was reduced to nitrite by vanadium chloride (III). Diazotization of sulfonamide by nitrous acid and its conjugation with a bicyclic amine produced a chromophor, which had max absorbance at 540 nm. The concentration of unknown samples was determined on the basis of standard curve. Results: The results showed that the standard curve was linear up to 150 mM. Sensitivity was 2 mM. Intra and inter assays coefficient of variations were less than 6% and the recovery was 91-93% indicating acceptable method precision and accuracy respectively. Conclusion: In conclusion the method developed had acceptable precision and accuracy for NO determination.

Introduction: Current data on the prevalence of coronary heart disease (CHD) and its associated risk factors in urban Iranian populations are scarce. Materials and methods: This study used data from the cross-sectional phase of the Tehran Lipid and Glucose Study (TLGS) conducted between 1999 and 2001. Subjects completed a standard questionnaire about past history of CHD and angina pectoris according to the Rose questionnaire. Standard supine ECG data were collected in 5984 men and women aged ³30 years and were coded according to the Minnesota criteria. All relevant data including anthropometric variables, fasting and 2-hour serum glucose (OGGT) and fasting serum lipids were collected. Multiple logistic regression analysis was used to determine the associated risk factors of CHD. Results: The age adjusted prevalences of angina pectoris, past history of CHD and ECG defined CHD were 10.7, 6 and 11.8% respectively. Subjects ³65 years had 62% higher prevalence of angina, more than 4-fold higher prevalence of previous history of CHD, and 2.7-fold higher prevalence of ECG-defined IHD (all p values <0.001) in comparison to a population aged 30-64 years. Women had significantly higher prevalence of angina pectoris (p<0.001) and men had higher rate of self reported history of CHD (P<0.01). The age adjusted prevalence of CHD based on the presence of any of the 3 conditions mentioned earlier was 21.8% with 22.3 and 18.8% in women and men respectively (P=0.05). Female sex, age, systolic blood pressure, body mass index, waist-to-hip ratio, 2- hour plasma glucose and the ratio of LDL to HDL-cholesterol were found to be the independent risk factors associated with CHD. Conclusion: These results demonstrate that CHD remains an important public health problem among the urban Iranian population, especially among women. An urgent national program needs to be implemented to reduce CHD risk factors by modifying diet and increasing physical activity.

Introduction: Though ECGs have limited accuracy for determining true prevalence of coronary heart disease (CHD), we studied individulas with CKD and DM, controlled for hypertension (HTN), to determine whether their ECG abnormalities could also reflect underlying coronary heart disease. Materials & Methods: Data were collected for 5942 men and women aged 30-69 years, participants of the Tehran Lipid and Glucose Study (TLGS), a cross-sectional phase of a large epidemiological study first initiated in 1999. ECG findings of all subjects were coded according to Minnesota ECG coding criteria. The Whitehall criteria for abnormal ECG findings that could represent ischemia were utilized. GFR was estimated using the Cockroft-Gault equation and diabetes was defined according to the American Diabetic Association (ADA) criteria. Subjects with moderate CKD and without DM were compared to the patients with DM without CKD. HTN prevalence was similar. The analysis was performed for all Whitehall ECG ischemia abnormalities combined, and separately for pathologic Q waves. Results: In spite of an overall similar prevalence of smoking, and a lower incidence of dyslipidemia and HTN, moderate CKD patients had a higher prevalence of Whitehall criteria abnormal ECG findings compared to the patients with DM. 19.7% of patients with CKD had abnormal ECG findings while 14.7% of diabetes patients had abnormal ECGs (p=0.02). The prevalence of Q waves was 11.5% in patients with CKD and 10.8% in patients with DM. In an age matched sub group of patients with DM and no CKD, the prevalence of ECG abnormalities was 19.3%, and similar to the patients with moderate CKD and no DM (19.7%) (p=0.9). In an age matched group the prevalence of pathologic Q waves was 11.45% compared to 11.5%, respectively. Conclusion: Moderate CKD is a major risk factor for the development of the Whitehall ECG criteria which have been associated with ischemic heart disease. The importance of CKD as a risk factor for ECG abnormalities is comparable with DM. Patients with moderate CKD probably are candidates for aggressive CHD risk modification.

Introduction: Among factors that may influence thyroid volume, one is parity. The purpose of this study was to evaluate the relationship between thyroid volume, urinary iodine concentration (UIC) and parity in pregnant women. Materials and Methods: For a total of 144 pregnant women, the relevant data was obtained from the Mahdieh hospital, in Tehran and studied. The women were divided into groups of UIC ³ 150 (iodine sufficient) and UIC < 150mg/l (iodine deficient). Questionnaires were used to obtain obstetric information from the pregnant women. Thyroid volume was measured by ultrasonography and urine samples were collected for urinary iodine measurement. Subjects were defined based on their history of pregnancies; nulliparous, one and ³ 2 parity. Results: Ninety-four women were iodine sufficient and fifty were iodine deficient. The mean ages for the iodine deficient and iodine sufficient groups were 25.0±5.0 and 25.5±5.0 respectively. After adjustment of ages in nulliparous, one and ³ 2 parity groups, the association between number of pregnancies and UIC was present only in iodine deficient women and between nulliparous and parous subjects. The means of UIC were 133±39 and 97±27 mg/l (p<0.01) in nulliparous and ³ 2 parity subjects respectively. However in iodine sufficient women, no significant difference was seen between the mentioned groups. Thyroid volume was the same in both groups. There was significant linear regression between urinary iodine and thyroid volume (r=0.29, p<0.05) in a total of 144 pregnant women. Conclusion: Significantly low UIC levels were found more among the parous as compared to the nulliparous iodine deficient women.