Dietary amino acids and anthropometric indices: Tehran Lipid and Glucose Study

ABSTRACT Objective: Recent studies investigated the role of amino acids (AAs) in weight management. We aimed to determine the association between AAs and three-year change of anthropometric indices and incident obesity. Materials and methods: Height, weight, hip, and waist circumference (WC) were collected at baseline and follow up. Three-year changes in anthropometric indices and obesity incident according to body mass index (BMI) (overweight & obesity) and WC cutoffs (obesity-WC) were ascertained. Dietary intakes of AAs were collected at baseline, using a food frequency questionnaire. Data analyses were conducted on 4976 adult participants and two subsamples, including 1,570 and 2,918 subjects, for assessing the AAs relationship with 3-year changes on anthropometric indices and obesity incident. Results: Lysine and aspartic acid were positively associated with higher weight change, whereas acidic AAs, cysteine, and glutamic acid showed a negative correlation with weight change. Furthermore, a weak positive correlation was shown for alkaline AAs, lysine, and valine with WC; however, acidic AAs, tryptophan, cysteine, and glutamic acid were negatively associated with WC. Aromatic and acidic AAs also demonstrated a weak negative relation with changes in BAI. Phenylalanine and Aromatic AAs showed a negative association with overweight &obesity incidence adjusting for potential confounders. Each quartile increases the dietary lysine, arginine, alanine, methionine, aspartic acid, and alkaline AAs related to a greater risk of obesity-WC, while tryptophan, glutamic acid, proline, and acidic AAs associated with lower obesity-WC risk. Conclusion: Our results suggested that certain dietary AAs may potentially change anthropometric indices and risk of obesity incident.

Dietary Quality among Tehranian Adults in Relation to Lipid Profile: Findings from the Tehran Lipid and Glucose Study.

The prevalence of dyslipidaemia has been increasing in developing countries that are undergoing nutrition transition. However, the association of diet quality and lipid profile has not been well-understood in these countries. The aim of the current study was to compare the ability of three diet quality indices—the Mediterranean diet scale (MDS), healthy eating index-2005 (HEI-2005), and diet quality index-international (DQI-I) in relation to changes in lipid profile between baseline and 6.7 years of follow-up. Baseline data from two 24-hour dietary recalls provided by 469 adults with mean age of 38.7±12.3 years, who were participants of the Tehran Lipid and Glucose Study, were analyzed to describe dietary intakes. Data on anthropometry, sociodemography, physical activity, and other lifestyle variables were recorded, and a comparison of baseline and follow-up data revealed changes in the concentrations of total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C). A general linear model was used in assessing changes in lipid profile depending on adherence to diet quality indices at baseline, after adjustment for age, smoking status, waist-circumference, body mass index, physical activity, and energy intake. A significant interaction was observed between scores and sex, and upon stratification, males in the highest quartile score of the HEI-2005 had significantly lower TG changes than those in the lowest quartile, after adjusting for confounders (-8.8 vs 2.9, p=0.038). No association was apparent in females (-0.2 vs 11.2, p=0.297). In addition, a positive association was found between DQI-I and HDL-C (Q1=0.6 vs Q4=-2.0, p=0.044) in males. In both sexes, all these indices were weakly associated with TC while none was associated with LDL-C. It is concluded: adherence to the HEI-2005 recommendations was weakly associated with reduced TG concentration in an urban Iranian adult population. The MDS and DQI-I were not related to change in lipid profile.

Analysis of loss of heterozygsity effect on thyroid tumor with oxyphilia cell locus in familial non medullary thyroid carcinoma in Iranian families.

Material and Methods: 22 nuclear families (78 persons including 12 patients) with papillary and follicular tumors were selected in a period of six months from Milad hospital. Five microsatellite markers (D19S413, D19S391, D19S916, D19S568, D19S865) on 19p13.2 were selected for genetic analysis. Genomic DNAs was extracted; PCR and polyacrylamide gel electrophoresis method were used for variation detection. Results: The results show that 5.4% of the follicular carcinomas and 17.9% of the papillary carcinomas presented LOH at recognition sites. LOH of Papillary carcinoma detected about 13.9% and follicular carcinoma 7.2% in this study. The frequency of informative cases was not similar for each marker: D19S413 (41.1%)[1], D19S391 (12.5%), D19S916 (10.7%), D19S568 (1.8%) and D19S865 (3.6%). Loss of hetrozygosity in D19S413 predicts the relation between variation in this region and the disease. Discussion: Our findings showed an average of 13.9% LOH in FNMTC cases. Among the five major microsatellites, D19S413 was the most informative for LOH analysis of FNMTC.

Does Dietary Intake by Tehranian Adults Align with the 2005 Dietary Guidelines for Americans: Observations from the Tehran Lipid and Glucose Study.

The aim of this study was to compare dietary intakes by Tehranian adults with recent dietary guidelines for the Americans. The study made a cross-sectional assessment of the dietary patterns of Tehranian adults using a validated food-frequency questionnaire. It included 2,510 subjects (1,121 men and 1,389 women) aged 19-70 years. They were the participants of the third follow-up survey of the Tehran Lipid and Glucose Study (2005-2008). The dietary patterns were assessed using the latest World Health Organization (WHO)’s nutritional goals and Dietary Guidelines for the Americans Adherence Index (DGAI) 2005. The mean [standard deviation (SD)] DGAI score for this population was 8.31 (1.9). Participants in the highest quartile category of DGAI were more likely to be female, older, non-smoking, and physically active than those in the lowest quartile category (p<0.001). Percentage of participants meeting the DGA recommendations was low, especially for starchy vegetables (2.3%), orange vegetables (16.2%), lean meat (9.2%), grains (12.0%), and legumes (6.4%). Over-consumption of grains was observed in almost half of the participants while approximately 20% of the subjects over-consumed milk and meat groups. Intakes of most nutrients examined were significantly associated with the DGAI 2005 score (p<0.001), except for vitamin E, vitamin B12, and vitamin D. The least adherence with the WHO goals was observed with n-3 PUFAs, sodium, fruit, and vegetable intakes. The results revealed that the dietary patterns of most Tehranian adults did not comply with the 2005 DGA and nutritional goals of WHO/Food and Agriculture Organization.

TaqI B1/B2 and -629A/C cholesteryl ester transfer protein (CETP) gene polymorphisms and their association with CETP activity and high-density lipoprotein cholesterol levels in a Tehranian population. Part of the Tehran Lipid and Glucose Study (TLGS)

We examined the cholesteryl ester transfer protein (CETP) gene TaqI intron 1 B1/B2 polymorphism and the -629A/C CETP promoter polymorphism in respect to high-density lipoprotein cholesterol (HDL-C) in a healthy Iranian population taken from the Tehran Lipid and Glucose Study (TLGS). The relationship between CETP activity and HDL-C level was also determined along with body mass index, blood pressure and tobacco smoking status. PCR-RFLP used to amplify a segment of the CETP intron 1 TaqI (B2/B1) polymorphism from 1021 individuals and we selected 345 individuals from the lowest, middle and highest HDL-C deciles and investigated the -629A/C polymorphism. We also evaluated the CETP activity of 103 of these individuals, each with at least one homozygous allele. The presence of the TaqI B2 and -629A/C A alleles were significantly associated with increased HDL-C levels (B2B2 = 1.19 ± 0.31 mmolL-1 vs. B1B1 = 1.01 ± 0.2 mmol L-1 for p < 0.001; AA = 1.15 ± 0.41 mmol L-1 vs. CC = 0.95 ± 0.28 mmol L-1 for p < 0.001) and decreased the CETP activity (B1B1 = 67.8 ± 8.9 pmol L-1 vs. B2B2 = 62.6 ± 9.6 pmol L-1 for p < 0.01; CC = 68.6 ± 8.4 pmol L-1 vs. AA = 62.7 ± 9.7 pmol L-1 for p < 0.002). The frequencies were 0.382 for the TaqI B2 allele and 0.462 for the -629A/C A allele, with linkage disequilibrium analysis giving D = 0.0965 and D' = 0.4695. We demonstrated that the TaqI B1 and B2 alleles and the -629A/C A and C alleles were in linkage disequilibrium in our population and that there was a significant association between the B2 and A alleles and high HDL-C levels and low CETP activity. Linkage disequilibrium between the TaqI A and B2 alleles also detected.

Insulin resistance in chronic hepatitis B and C.

AIM: To determine whether insulin resistance occurs in patients with chronic hepatitis B (CHB) and chronic hepatitis C (CHC) and its relationship with the presence of liver fibrosis and steatosis. METHODS: Untreated patients with CHC (n=60) or CHB (n=40), similar in age, gender, body mass index and waist-hip ratio, were studied. Relationship between anthropometric, biochemical (fasting serum insulin, C-peptide, ferritin, iron, TNF-alpha, cholesterol, triglyceride, bilirubin, hemoglobin and platelet concentrations) and liver biopsy (43 CHC and 20 CHB patients) findings was investigated by insulin resistance determined via the homeostasis model assessment (HOMA-IR). RESULTS: The mean fasting serum insulin was 14.9 (11.9) mU/mL in CHC and 21.4 (17.4) in the CHB group (normal range 0.7-9; p=0.049) and mean HOMA-IR was 3.1 (2.6) in CHC versus 4.7 (4.1) in the CHB group (normal range 0.12-4.61; p=0.036). HOMA-IR was significantly associated with fibrosis stage in the CHC group (p=0.015), but not in the CHB group. CONCLUSION: Hyperinsulinemia occurs in chronic viral hepatitis B and hepatitis C; insulin resistance is associated with stage of fibrosis in hepatitis C.

Congenital hypothyroidism in Iran.

OBJECTIVE: Following elimination of iodine deficiency in Iran, the program of screening for congenital hypothyroidism (CH) was established in 1998. The descriptive findings of the study are reported here. METHODS: From February 1998 to June 2001, cord blood spot samples from 8 hospitals and a rural birth center in Tehran and Damavand were collected and tested for TSH measurement using a two-site IRMA method. TSH values > or = 20 microU/mL were recalled. The diagnosis of CH was confirmed using age adjusted reference values for serum TSH and T4 levels. RESULTS: Of 20107 screened neonates, 256 had cord TSH values > or = 20 microU/mL (recall rate: 1.3%) and 22 showed hypothyroidism (1:914 live births). History of maternal ingestion of drugs and dietary goitrogens were negative and minimal, respectively. 15 out of 21 CH neonates had parental consanguinity. The odds ratio of CH occurrence in blood-related to non-related marriages was 6.9 (CI=1.82-25.87). Thyroid dysgenesis occurred in 10 neonates; 1:2011 births. Urinary iodine excretion was between 12-22 (n=3) and 40-42.5 (n=5) microg/dL in 10 eutopic neonates (2 not assessed). CONCLUSION: Parental consanguinity and iodine excess could be the causative factors for the high incidence of CH.