[Home ] [Archive]   [ فارسی ]  
:: Main :: About :: Current Issue :: Archive :: Search :: Contact ::
Main Menu
Journal Information::
Articles archive::
For Authors::
For Reviewers::
Contact us::
Site Facilities::
Search in website

Advanced Search
Receive site information
Enter your Email in the following box to receive the site news and information.
Last site contents
:: Editorial Board
:: About Iranian Journal of Endocrinology and Metabolism
:: Volume 2, Issue 3 (9-2000) ::
2000, 2(3): 151-158 Back to browse issues page
Association of serum lipoproteins, apolipoproteins, and HDL-associated paraoxonase enzyme activity with thyroid function
F Azizi , F Raiszadeh , M Rahmani , SM Solati , M Arabi , M Hedayati
Abstract:   (33339 Views)
Abstract: Thyroid dysfunction, specially hypothyroidism is associated with an increased risk of atherosclerosis, which is attributed to impaired metabolism of atherogenic lipids and lipoproteins. Human paraoxonase (PON) is an HDL-associated enzyme which is believed to protect lipoproteins against oxidative modification. We have studied the status of lipids, apolipoproteins, and activity of paraoxonase enzyme in 14 hypothyroid (7 females and 7 males), 8 hyperthyroid (4 females and 4 males), and 32 euthyroid subjects (18 females and 14 males). Apolipoprotein (apo) concentrations were measured in a fasting serum sample by immunoturbidometric assay and paraoxonase/arylesterase activities by spectrophotometric assay of p-nitrophenol/phenol production following addition of paraoxon/phenylacetate. Hypothyroid subjects had significantly higher levels of total cholesterol (204±69 vs 171±37, p<0.05) and low-density lipoprotein cholesterol (LDL-c) (115±49 vs 82±34, P<0.05) and lower levels of high-density lipoprotein cholesterol (HDL-c) (52±15 vs 63±17, P<0.05) than euthyroid controls. The ratios of TC/HDL-c (4.0 ± 1.3 vs 2.9 ± 1, P<0.01) and LDL-c/HDL-c (2.3 ± 0.8 vs 1.5 ± 0.8, P<0.01) were significantly higher in hypothyroid subjects than in controls. As compared to healthy controls, hyperthyroid subjects had lower levels of HDL-c (50±10 vs 63±17, P<0.05) and lower activity of paraoxonase enzyme (27±14 vs 66±41, P<0.01). No significant difference was observed between the hypo- and hyperthyroid subjects with euthyroid controls in serum levels of total cholesterol(TC), triglycerides(TGs), apo A-I, apo B, and arylesterase activity. Serum concentration of TSH had a significant positive correlation with TC and LDL-c, serum T3 was negatively correlated with TC and apo B and serum T4 level was negatively correlated with TC and LDL-c Significant negative correlation was observed between serum T4 and paraoxonase activity (r=-0.3, P<0.05). The results demonstrate that both hypothyroidism and hyperthyroidism are associated with atherogenic lipid profiles. Correlation between thyroid hormones, paraoxonase enzyme activity, and lipid levels confirms the role of thyroid hormones in the metabolism of lipids and their associated enzymes. The higher LDL oxidation previously observed in hyperthyroid subjects can be attributed to decreased HDL paraoxonase activity.
Keywords: Paraoxonase, Lipoprotein, Apolipoprotein, Hyperthyroidism, Hypothyroidism
Full-Text [PDF 280 kb]   (6526 Downloads)    
Type of Study: Original | Subject: Endocrinology
Received: 2006/11/15 | Published: 2000/09/15
Add your comments about this article
Your username or Email:


XML   Persian Abstract   Print

Download citation:
BibTeX | RIS | EndNote | Medlars | ProCite | Reference Manager | RefWorks
Send citation to:

Azizi F, Raiszadeh F, Rahmani M, Solati S, Arabi M, Hedayati M. Association of serum lipoproteins, apolipoproteins, and HDL-associated paraoxonase enzyme activity with thyroid function. Iranian Journal of Endocrinology and Metabolism 2000; 2 (3) :151-158
URL: http://ijem.sbmu.ac.ir/article-1-101-en.html

Rights and permissions
Creative Commons License This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.
Volume 2, Issue 3 (9-2000) Back to browse issues page
مجله ی غدد درون‌ریز و متابولیسم ایران، دو ماهنامه  پژوهشی مرکز تحقیقات غدد درون‌ریز و متابولیسم، Iranian Journal of Endocrinology and Metabolism
Persian site map - English site map - Created in 0.09 seconds with 38 queries by YEKTAWEB 4624