A programme of iodine supplementation using only iodised household salt is efficient--the case of Poland.

BACKGROUND: Iodine prophylaxis in Poland started in 1935 and has been interrupted twice: by World War II and in 1980 for economic reasons. Epidemiological surveys carried out after the Chernobyl accident in 1989 as well as in 1992/1993 and in 1994 as a 'ThyroMobil' study, revealed increased prevalence of goitre in children and adults. Ninety per cent of Poland was classified as an area of moderate iodine deficiency, and 10%, in the seaside area, as mild iodine deficiency territory. Iodine prophylaxis based on iodisation of household salt was introduced again in 1986 as a voluntary model and in 1997 as a mandatory model with 30+/-10 mg KI/kg salt. OBJECTIVE: The evaluation of the obligatory model of iodine prophylaxis in schoolchildren from the same schools in 1994 and 1999. METHODS: Thyroid volume was determined by ultrasonography. Ioduria in casual morning urine samples was measured using Sandell-Kolthoff's method, within the framework of the ThyroMobil study. RESULTS: Goitre prevalence decreased from 38.4 to 7% and urinary iodine concentration increased from 60.4 to 96.2 microg/l mean values between 1994 and 1999. In four schools the prevalence of goitre diminished below 5%. In 1999, 70% of children excreted over 60 microg I/l, and 36% over 100 microg I/l, whereas in 1994 the values were 44 and 13% respectively. CONCLUSION: The present findings indicate that iodine prophylaxis based only on iodised household salt is highly effective.

[Iodine deficiency and thyroid neoplasms in the Krakow region]. / Niedobór jodu a rak tarczycy w regionie krakowskim.

The aim of the study was to evaluate the correlation between incidence rate (IR) of thyroid cancer and severity of iodine deficiency. The influence of iodine prophylaxis on IR was also investigated. The suspension of iodine prophylaxis in 1980 resulted in goitre prevalence increase in schoolchildren (up to 60%) and elevated TSH levels in neonates observed in early 1990-ties. In 1990 rise in thyroid cancer IR was observed. IR of papillary and follicular carcinoma in 1995 were 1.6 and 1.5 respectively. Papillary to follicular ratio was about 1.0. Such a high prevalence of follicular cancer was specific for iodine deficient regions. In 1997, after introduction of mandatory model of iodine prophylaxis in Poland, increase in papillary thyroid cancer IR was observed, reaching in 1998 6.23 per 100,000 inhabitants. Papillary to follicular cancer ratio rose to 2.48. In 1999 no further increase in thyroid cancer IR was observed. Increase in papillary cancer incidence between 1990 and 1999 may be related to overlapping of iodine deficiency and other cancer risk factors i.e. radiation after Chernobyl accident.

[Visual disability due to diabetes in Cracow voivodeship]. / Inwalidztwo wzroku spowodowane cukrzyca na terenie województwa krakowskiego.

Visual impairment and blindness are major complications of diabetes and are regarded as the most serious disability by most of patients. The purpose of the study was to determine the incidence and prevalence due to diabetes-induced visual disability in 1991-1999 in the former Cracow voivodeship with population of 1,245,047 inhabitants. A register of visual disability was established using independent sources of information. On the end of 1999 the register had included 122 diabetics with visual disability--66 women (54.1%) and 56 men (45.9%). The patients with type 2 diabetes predominated--92 subjects (75.4%). The remaining 30 patients (24.6%) had type 1 diabetes. Grade 1 visual disability was diagnosed in 82 subjects (67.2%) whereas grade 2 visual disability in 40 patients (32.8%). Grade 1 visual disability was defined as visual acuity in a better eye < 0.05 and visual field narrowing < 20%. The criteria of grade 2 were visual acuity after correction in a better eye 0.05-0.1 and visual field narrowing 20-30%. According to the register of the Cracow Branch of the Polish Association of the Blind diabetics made up 6.2% of all visual disability cases. In 1991-1999 the incidence of visual disability due to diabetes did not increase significantly. The mean incidence rate was 0.9/100,000 population. However, there was a significant increasing trend in prevalence with mean annual increase of 0.24/100,000 population (95% CI 0.17-0.31/100,000).

Influence of iodine deficiency and iodine prophylaxis on thyroid cancer histotypes and incidence in endemic goiter area.

The aim of the study was to evaluate the correlation between thyroid cancer histotype and incidence rate (IR) and iodine nutrition level in two endemic goiter areas: the districts of Krakow and Nowy Sacz. The suspension of iodine prophylaxis in Poland in 1980 resulted in increased goiter prevalence in schoolchildren and adults and elevated TSH levels in newborns in the early 1990s. Since 1992 a rise in thyroid cancer IR was observed. Thyroid cancer IR in the Krakow population was 2.22 in 1986; 3.62 in 1995 and 6.02 in 2001; in Nowy Sacz: 1.52; 2.59 and 3.88 respectively. In 1986 papillary/follicular cancer ratio in both areas was about 1.0--the value typical of iodine deficient areas. After restoring the obligatory iodine prophylaxis in 1997, a significant decrease in elevated TSH concentration in newborns and urinary iodine concentration increase in schoolchildren were observed. A relative rise in the incidence of papillary thyroid cancer and decrease in follicular cancer, resulting in rise in papillary/follicular thyroid cancer ratio up to 5.9 in 2001 was also observed. Since 1999 no further thyroid cancer IR increase was noted. In conclusion, a significant increase in differentiated thyroid cancer IR was observed in association with the iodine prophylaxis suspension. Changes in thyroid cancer histotypes in 1986-2001 and a significant decrease in incremental rate of differentiated thyroid cancer probably reflect the influence of effective iodine prophylaxis. The significant difference between IR of thyroid cancer incidence in the districts of Krakow and Nowy Sacz may be related to differences in the exposure to radiation after the Chernobyl accident.