[Effectiveness of iodine prophylaxis in hypertensive patients on salt restricted diet].
BACKGROUND: Iodine prophylaxis in Poland started in 1935 however it has been interrupted during Second World War, and also in 1980. In January 1997 a new approach of preventing iodine deficiency was introduced as obligatory iodination model of household salt to be extent of 30 mg KI/kg. The aim of the study was to determine iodine intake after introduction of mandatory salt iodization in group of persons being on low salt diet because of hypertension. Investigated group and methods: The study was performed on 227 persons (94 males and 133 females), aged 18-89 years (average age 56 +/- 15,2 years). Each person answered questions concerning salt consumption and other products being additional source of iodine (fishes, pharmaceutical preparations containing iodine). Subjects were divided into two groups: according to the amount of salt consumption (119 persons restricted to household salt and 108 persons used kitchen salt) and according to the value of blood pressure (170 persons was hypertensive and 57 persons was normotensive). The urine iodine concentration (UIC) was determined in morning urine samples by the method of Sandell and Kolthoff. RESULTS: The average UIC in the whole studied group was 156,1 +/- 124,9 microg/l. Woman showed lower UIC than man (132,9 microg/l vs 177,5 microg/l). In 8% of patients iodine concentration was below 50 microg/l and in 64% of patients it was 100 microg/l or more. In the case of persons consuming limited, low amount of salt, the average urine iodine concentration was 150,3 microg/l, whereas those who add some salt to a dish was 162,4 microg/l. In hypertension patients ioduria was lower than in persons with normal blood pressure (153,1 microg/l vs 164,9 microg/l). CONCLUSIONS: The model of iodine prophylaxis has used in Poland is effective. It also concerns persons consuming limited amount of salt in the our studies group. The amount of consumed salt should be determined by measuring of Na+ concentration in 24-hour urine collection. Additional monitoring of iodine supply is necessary because of possible consumption of iodine from other sources than salt.