Thyrotoxic Periodic Paralysis in Azari Iranians

Thyrotoxic periodic paralysis (TPP) is a fairly common accompaniment of thyrotoxicosisin Orientals. The disorder is a rare complication of thyrotoxicosis in the United States and Europe. There is no published study on the prevalence of hypokalemic periodic paralysis in thyrotoxic Iranian patients. In order to obtain a fairly good estimate, the prevalence of TPP among thyrotoxic patients from the northwestern part of Iran (east Azerbaijan province) was investigated. All new cases of thyrotoxicosis attending the endocrine clinics of Tabriz University of medical sciences were questioned specifically on the occurrence of periodic paralytic attacks. Only patients who had experienced one or more attacks of flaccid paralysis of extremities lasting from a few hours to few daysand followed by complete spontaneous or inhospital recovery were included. Thirty-nine patients were evaluated during paralytic episodes. In 14 cases, diagnosis was based on typical and compatible history given by thyrotoxic patients. During a 10-year period between 1989 and 1999 a total of 5463 patients were seen with thyrotoxicosis of various etiologies. Of these patients, 4451 (81.5%) were female and 1012 (18.5%) were males. Among this thyrotoxic population,there were 53 proved cases of TPP (4 females and 49 males). All patients were Iranian from the northwestern part of the country; the prevalence of TPP among male patients was 4.8% and among thyrotoxic females 0.08%, with an overall prevalence of 0.97% This prevalence rate is one half the rates reported from Japan and China and approximately 10 times the rate reported from the United States. It is concluded that TPP is a relatively common complication of thyrotoxicosis in Azari Iranians. Physicians should be cognizant of this condition to ensure early diagnosis and treatment of a potentially life-threatening but remediable disorder.