International Journal of Endocrinology and Metabolism
Year:2005 | Volume:3 | Issue:2|Papers Count:8

Subclinical hypothyroidism is defined as serum TSH levels above the upper limit of normal (4.0 or 5.0 mIU/L depending on the laboratory) despite normal serum free thyroxine.For diagnosis of subclinical hypothyroidism, other causes of elevated TSH, such as recovery from non-thyroidal illness, assay variability, heterophile antibodies, and certain cases of central hypothyroidism with biologically inactive TSH, should be excluded.

Overt hypothyroidism has been found to be associated with cardiovascular diseases. Whether or not subclinical hypothyroidism is also a risk factor for cardiovascular disease is controversial. The aim of this study was to investigate serum thyrotropin levels and subclinical hypothyroidism in relation to presence and extent of coronary artery disease (CAD). Materials and Methods: In a sample of 390 persons (239 men and 151 women) with mean age of 55.12±10.52 years who had referred for coronary angiography, data on general health, thyroid status, medications and previous myocardial infarction were obtained at baseline. They were screened for impaired thyroid function using a sensitive immunoradiometric assay for thyrotropin. Subclinical hypothyroidism was defined as an elevated serum thyrotropin level (≥ 4. 0mU/L) and a normal serum free thyroxine level. A sin-gle-, two or triple vessel disease or normal ves-sels was documented by coronary angiography. Results: Subclinical hypothyroidism was present in 6.4% of persons and was not associated with a higher frequency (P=0.51) or greater severity (x2=2.172; P=0.70) of CAD. The mean serum thyrotropin level was significantly higher in women (P<0.001). There was neither correlation between serum thyrotropin level and the presence of CAD (P=0.37) in either sex (men: P=0.67 /women: P=0.97) nor with the extent of CAD (P=0.30) in either of the two groups (men: P=0.70 /women: P=0.34). Also, serum thyrotropin level was not higher significantly in patients who had has previous myocardial infarction (P=0.95). Conclusions: There was no correlation between thyrotropin levels or subclinical hypothyroidism and presence or severity of CAD in a cohort of patients who referred for coronary angiography

We aim to evaluate a non-mydriatic retinal camera as a safe and efficacious screening tool, for diabetic retinopathy, in diabetes centers. Materials and Methods: 221 consecutive patients attending a Diabetes Center submitted to retinal photographs using a non-mydriatic camera. Patients were included if they had not had previous laser therapy and if they had a formal ophthalmologic consultation within 6 months of the photography Four endocrinologists reviewed the retinal photographs and recommended an interval (urgent referral, early referral, non-referral) for ophthalmologic assessment. Endocrinologists’ grades were compared against the gold standard of ophthalmological findings. The endocrinologists were privy only to the patient’s age, type and duration of diabetes mellitus. Results: Twenty-seven cases were deemed as requiring early referral by the ophthalmologists. The endocrinologists agreed with ophthalmologist referral times in 27, 26, 23 and 27 cases respectively. Two cases requiring urgent referral according to the ophthalmologists were also judged as requiring urgent referral by all endocrinologists. A mean sensitivity of 95.4% (95% CI 88.5%-100%) was attained. Conclusions: The use of a non-mydriatic camera to determine need for ophthalmologic referral was found to be safe and efficacious, with no serious delays in referral noted. On average this tool can safely defer 53.5% of routine ophthalmologic referrals without any risk to the patient’s eyesight.

The purpose of this study was to investigate the effect of exercise and post dehydration water drinking on variations in plasma arginine vasopressin (PAVP), plasma osmolality (Posm) and tympanic temperature (Ttym) in healthy males.Materials and Methods: Eight healthy young males (27.4+/-0.8 yrs old) volunteered for the study. They performed constant work exercise, at a rate of 60 rpm at 50% of individual work load for VO2 peak for 30 minutes. Six blood samples (at minutes 0, 15 and 30 during exercise and at minutes 3, 15 and 30 after termination of exercise) were obtained through an indwelling venous cannula. Plasma concentrations for Na+, and AVP were determined. Posm was calculated using Na+ concentrations. Simultaneous variations in Ttym were also determined. Results: Our results demonstrated a positive correlation between increase in PAVP and both Posm and Ttym during exercise but not during the recovery period. When exercise was combined with water drinking a fast and significant suppression in PAVP occurred (P<0.05). Conclusions: These results suggest that Posm and Ttym have no significant effect on AVP secretion post exercise, and thus other factors must be involved in AVP secretion during post exercise recovery period.

The main objective of this research was to determine the effects of soy protein isoflavones on serum lipids, lipoproteins and fasting blood sugar levels in hypercholesterolemic rabbits. Materials and Method: Twenty-four male New Zealand rabbits received the basic pellet diet for two weeks and were then placed on a hypercholesterolemic diet (pellets plus 1% cholesterol) for three weeks. After elevation of total cholesterol, the rabbits were randomly allocated into four experimental groups. Groups 1 to 3 received 100g soy protein containing 200mg (SPI+), 100mg (SPI50%) soy protein diet and without isoflavones (SPI-), respectively, for six weeks. The fourth group was kept on the hypercholesterolemic diet (HC). Results: Findings showed that cholesterol rich diet produced significant increase in total, LDL- and HDL-cholesterol concentrations. In SPI+ group these parameters remained unchanged, compared with SPI- and SPI50% groups (P<0.0001). HDL-cholesterol was significantly elevated after administration of HC diet and remained high (almost three fold) in all soy diets relative to baseline. However, its level was significantly lower in SPI50% compared with SPI-group (p<0.01). Triglycerides and VLDL concentrations were significantly increased in SPI50% compared with baseline and HC groups (P<0.03). Fasting blood sugar levels were not changed in all soy treatment groups. Conclusions: These results suggest that intact soy protein isoflavones ameliorate the lipid pro-file in spite of high-cholesterol intake, but has no obvious effect on blood sugar levels and can therefore be useful in hyperlipidemias especially when cholesterol intake is simultaneously decreased. Moreover, there is no direct dose-response relationship between soy isoflavone content and its lipid-lowering effect

Ageing effects on the in vivo cyclic 3,5’-adenosine monophosphate (cAMP) production by the adrenal cortex were studied in the rat. Materials and Methods: Eleven old (from 23 to 29 months) and 13 young (from 4 to 5 months), dexamethasone pretreated Long-Evans female rats received 5.0 mu.i. (1-24) ACTH/100g b.w. by intravenous injection. The plasma concentration of corticosterone as well as the adrenal contents in cAMP and corticosterone was measured, by radioimmunoassay, just before and 45 min after the (1-24) ACTH injection. Results: The basal plasma corticosterone level and the adrenal contents in corticosterone and cAMP were low and no group difference was observed. The (1-24) ACTH injection causes significant increases in the plasma corticosterone level and the glandular contents in corticosterone and cAMP, which were lesser in the old animals than in the young ones; the differences aged/young were approximately –37%, –18% and –55% respectively. Conclusions: These results suggest that the reduced steroïdogene response of the adrenal cortex in the old rat, to an acute ACTH administration, is at least partly due to a decrease in the cellular production of the principal second messenger of this hormone, i.e. the cAMP.

The relationship between thyroid disorders and glaucoma is not clear. This study aimed at determining the prevalence of thyroid functional disorders in patients with glaucoma.Materials and Methods: 201 patients with glaucoma referring to Farabi Hospital were selected using simple non-random sampling. Intra ocular pressure (IOP) was measured and thyroid function tests (TFT) were done and the patients were divided into different groups according to their thyroid function status (hypo-,eu-and hyperthyroid).Results: Mean age of the patients was 54±17 years. Of the patients, 26.9% had open angle glaucoma (OAG), and the remaining had non-open angle glaucoma (NOAG). Of 201 patients, 8 cases (4%) were hypothyroid and 17 cases (8.5%) were hyperthyroid. The mean intraocular pressures of the hypo-, eu- and hyperthroids were 18.1±9.3, 16.8±3.7 and 14.2±3.3 mmHg, respectively, which showed no significant difference. Mean IOP in patients with goiter was significantly lower than in those without goiter (16.0±5 vs.17.1±7 mmHg, p<0.05). No significant difference in the prevalence of thyroid disorders was found between those with OAG and NOAG.Conclusions: Compared to other studies the prevalence of thyroid disorders in patients with glaucoma is higher than that of the normal population. Our findings controvert the results of some other studies, in which higher prevalence of hypothyroidism in OAG than that of NOAG was observed.

In the diagnosis of Pendred syndrome, assessment of individuals by molecular analysis of the SLC26A4 gene is recommended. Here we report a novel mutation in the SLC26A4 gene as revealed by denaturing high performance liquid chromatography (DHPLC) and DNA sequencing of the entire coding region of the SLC26A4 gene in five members of an Iranian family affected with Pendred syndrome. This is the first report of the molecular investigation of Pendred syndrome in Iran and the first report of the R79X mutation.