The Prevalance of Hypercholesterolemia in Middle-Aged and Elderly Population in Mashhad And its Relation to Hypothyroidism

Document Type : Research Paper




ntroduction: Both overt hypothyroidism (OH) and subclinical hypothyroidism (SH) have been reported to have side effects on body organs. Hypothyroidism can cause hypercholesterolemia, hyperlipidemia and diastolic hypertension, which are regarded as risk factors in development of coronary heart disease (CHD); on the other hand, the hypercholesterolemia due to hypothyroidism can be easily treated with levothyroxine. This study was performed to determine the prevalence of hypothyroidism in hypercholesterolemic subjects in Mashhad.
Material and Methods: This descriptive study was performed in Mashhad City from May to Nowember 2002. A number of 4300 men and women aged 40 year or over in 97 different regions in Mashhad were interviewed and 2222 subjecs volenteerly encountered the study. A sample of 12-14 hr fasting blood was taken from volunteers and the total cholesterol (TC) was determined by enzymatic method (zist chime-Iran) for 2215 (758 men and 1457 women) subjects. Serum FT4 and TSH were determined by radio-immunoassay methods for 89 subjects with TC≥310 mg/dl and for 82 subjects with TC: 261-309 mg/dl. Individual and laboratory data were gathered in a questionnaire and analyzed using descriptive statistics and frequency destribution tables and χ2 t-test.
Results: The results showed that 4.9% of men had TC ≥310mg/dl, 11.9%, 42.2% ,and 41% had TC concentrations of 261-309, 200-260 ,and 200g/dl. Twelve out of 89 (13.5%) subjects with TC>310 mg/dl were hypothyroid; 6 with OH (4women & 2men) and 6 with SH (5women & 1man). Hypothyroidism in women was more frequent than men and the female /male ratio was 3/1. The correlation between hypercholesterolemia and hypothyroidism at TC>322 mg/dl was significant (χ2=4.01, df=1, P=0.045). FT4 level in TC ≥310mg/dl was 13.05± 3.4, and in TC between 261-309 mg/dl 14.2±2.63; which was significant in the first group (t-test, p=0.024).
Conclusion: These data demonstrated that hypercholesterolemia is prevalent in mean-aged and elder people in Mashhad and hypothyroidism, especially. SH form, is also frequent in hypercholesterolemic subjects. Female to male ratio is about 3:1, but seemingly younger women in Mashhad are more affected than what is seen in other studies. Therefore, the screening of thyroid function in hypercholesterolemic subjects especially in women is recommended.


1- Thomas D, Collet JP, Cottin Y, Cournot M, Ducimetiere P, Ferrieres J, et al. The best of epidemiology and
cardiovascular prevention in. Arch Mal Coeur Vaiss 2007;1:57-64.
2- Kitayama J, Faraci FM, Lentz SR, Heistad DD. Cerebral vascular dysfunction during hypercholesterolemia. Stroke
2007. (Epub ahead of print) [Medline].
3- Jeffrey MH. Lipoproteins and atherogenesis. Endorinol and Metabol Clin Nort Am 1998; 27:569-584.
4- Kreisberg RA, Oberman A. Lipids and atheroscerosis:lessons learned from ranndomized controlled trials of lipid
lowering and other relevant studies .J of Clinical Endocrinol &Metabol 2002; 87(2):423-437.
5- Kromhout D, Menotti A, Kesteloot H, Sans S. Prevention of coronary heart disease by diet and lifestyle evidence
from prospective cross-cultural , cohort , and intervention studies. Circul 2002; 05:893-898.
6- Laber U, Kober T, Schmitz V, Schrammel A, Meyer W, Mayer B, et al. Effect of hypercholesterolemia on
expression and function of vascular soluble guanyly cyclase.Circul 2002; 105:855-860.
7- Scott MG. The role of cholesterol management in coronary disease risk reduction in elderly patients. Endorinol
Metabol Clin North Am 1998; 27:655-675.
8- Cobbold C A, Sherratt J A, Maxwell S R J. Lipoprotein oxidation and its significance for Atherosclerosis: a
mathematical approach. Bull mathemat biolo 2002; (64): 65-69.
9- Bemben DA, Winn P , Hamm RM, Mergen L, Davis A, Barton E. Thyroid disease in the elderly . part I
.prevalence of undiagnosed hypothyroidism. J Fam Pract 1994 Jun; 38(6):577-82.
10-Biondi B, Palmieri EA, Lombardi G, Fazio S. Effects of subclinical thyroid dysfunction on the heart. Ann Intern
Med 2002; 137:904-914.
11-Monzani F, Caraccio N, Del Guerra P, Casolaro A, Ferannini E. Neuromuscular symptoms and dysfunction in
subclinical hypothyroid patients : benefical effect of L-T4 replacement therapy. Clinic Endocrinol 1999; 51:237-242.
12-Bindels AJ, Westendorp RG, Frolich M, Siedell JC, Blokstra A, Semlt AH. The prevalece of subclinical
hypothyroidism at different total plasma cholesterol levels in middle age men and women ,a need for case finding ?.
Clin Endocrinol 1999; Oxf 50(2): 217-20 .
13-Diekman T, Lansberg PJ, Kasterlein JJ, Wiersinga WM. Pervalence and correction of hypothyroidism in a large
cohort of patients referred for dyslipidemia. Arch Intern Med 1995; 155(14):1490-5.
14-Elder J, McLelland A, OُReilly DSTJ, Packard CJ, Seriese JJ, Shepherd J. The relationship between serum
cholesterol and serum thyrotropin, thyroxine and troidotropine concentrations in suspected hypothyroidism. Ann Clin
Biochem 1990; 27:110-113 .
15-Centanni M, Cesareo R, Verallo O, Brinelli M, Canettieri G, Viceconti N, et al.Reversible increase of intraocular
pressure in subclinical hypothyroid patients. Eur J Endocrinol 1997; 136(6):595-8.
16- حاج زاده موسی الرضا، رحیقی جواد، آقائی آزیتا. تغییرات عناصر معدنی در بافت های کلیه، کبد، قلب و عضله اسکلتی در رت هیپوتیروئید. مجله علوم پایه
پزشکی ایران ،جلد 8،شماره 1380)3)ص 152-147.
حاج زاده موسی الرضا، رحیقی جواد، آقائی آزیتا. اثرات کم کاری تیروئید بر عناصر معدنی در بافت های مغز، استخوان جمجمه و پوست در موش صحرایی. مجله
.243-237 ص(1385)4 شماره ،9 جلد ،علومپایهپزشکی
17-Levy EG. Thyroid disease in the elderly. Med Clin Nort Am 1991; 75(1):151-167.
18-Luboshitzky R, Aviv A, Herer P, Lavie L. Risk factor for cardiovascular disease in women with subclinical
hypothyroidism. Thyroid may 2002; 12(5):421-5.
19-Bemben DA, Hamm RM, Morgan L, Winn P, Davis A, Barton E. Thyroid disease in the elderly part 2.
perdictability of subclinical hypothyroidism. J Fam Pract 1994 Jun ; 38(6):583-8.
20-Series JJ, Biggart EM, O’Reilly DSTJ, Packard CJ, Sheperd J. Thyroid dysfunction and hypercholesterolaemia in
the general population of Glasgow, Scotaland. Clinica Chimica Acta 1998; 172:217-222.
21-Manciet G, Dartigues JF, Decamps A, Barberger GP, Letenneur L, Latapie MJ, et al. The PAQUID survery and
correlates of subclinical hypothyroidism in elderly community residents in the south west of France. Age-Ageing
1995; 24(3):235-41.
22- Rivolta G, Cerutti R, Colombo R, Miano G, Dionisio P, Grossi E. Prevalence of subclinical hypothyroidism in a
population living in the Milan metropolitan area. J Endocrinol Invest 1999; 22(9):693-7. 
24- حاج زاده موسی الرضا، میرزایی جمال. بررسی ارتباط کم کاری تیروئید با بالا بودن چربیهای خون در مراجعه کنندگان به آزمایشگاههای دانشگاهی در مشهد
.مجلهعلومپایهپزشکی ایران 1380؛ جلد 4، شماره 1380)، 3)ص 122 تا 129.
25-Gloria LV, Dallas T. Obesity, the metabolic syndrome, and cardiovascular disease. Am Heart J 2001; 142:1108-
26-Scott MG. Cholesterol managament in the era of managed care. Am J Cardiol 2000; 85:3A-9A.
27-Sunil VR, Mark D, F.Xavier Pi-S, et al. Obesity as a risk factor in coronary artery disease. Am Heart J 2001:
28-Tietz NW. In:Titez N.W (eds) Text book of Clinical Chemsitry. First ed. Philadelphia: WB Saunders; 1987. P.360,
29-Pirich C, Müllner M, Sinzinger H. Prevalence and relevance of thyroid dysfunction in 1922 cholesterol screening
participants. J Clinic Epidemiol 2002; 53:623-629.
30-Sawin CT. Subclinical hypothyroidism in older persons. clin Geriatr Med 1995; 11(2): 231-8.
31-Weber KA. Subclinical thyroid dysfunction. Arch Intern Med 1997; 26:157(10):1065-8.