Urinary Iodine Levels in Sudanese Patients with Thyroid Disorders

Abstract

It is evident that, in the last years there is an increase incidence of thyroid disorders in Sudanese people. This study was conducted essentially to know the effects of age, sex and residence on the incidence of thyroid disorders, and to know the influence of iodine status of a subject on thyroid function by measuring urinary iodine concentration. A total of 100 Sudanese patients, with thyroid disorders visiting the Radiation and Isotope Centre (RICK) at Khartoum, during the period of February 2005 to July 2005, were selected randomly to contribute in this study. A total of 30 healthy subjects from the co-patients were volunteered to participate in this study as a control group. Specimens of sera and urine samples were collected from all patients and controls to estimate thyroid hormones, T3 & T4 by (RIA) method and TSH by (IRMA) method. Urine samples were used to measure urinary iodine concentration by Sandle Koltholt Reaction (using ammonium persulfate as a catalyst). The patients were categorized as hyperthyroidism and hypothyroidism. There is an increased incidence of hyperthyroidism in the middle aged patients, while hypothyroidism is more common in the elderly, the results were found to be as follows: - In the hyperthyroidism (n=80): there were 16 patients (20%) of age < 20 years, 43 patients (53.3%) aged between 20-40 years, and 21 patients (26.2%) of age > 40 years. - In hypothyroidism (n=20): there were 2 patients (10%) of age < 20 years, 6 patients (30%) aged between 20-40 years and 12 patients (60%) of age > 40 years. Females were more susceptible to thyroid disorders than males for both hyperthyroid and hypothyroidism : - In hyperthyroidism females were 65 out of 80 (81,3%) . - In hypothyroidism females were 14 out of 20 (70%). The disease was found to be distributed in all regions of Sudan, with increased incidence of hyperthyroidism in Central-Sudan (Khartoum State & Gazera area) (47.5%), North (18.8%), East (5%), West (13.7%) and South (5%) while for hypothyroidism there was increased incidence in the West (45%), Central-Sudan (26%), North (25%), East (5%), South (0%). In this study, urinary iodine concentration was found to be highly significantly raised in patients with hyperthyroidism compared to the control (P<0.01), while highly significantly reduced in patients with hypothyroidism (P<0.01). From this study it is recommended that urinary iodine could be used as a screening and diagnostic test for both hyper and hypothyroidism.