Browsing by Subject "kilpirauhanen"

Hovawart is an old German working dog breed. Few hundred dogs are registered annually in Finland. Hovawarts can be seen in working trials as well as a family pet. In Hovawart breeding program (JTO) hypothyroidism is mentioned as a one of the most common hereditary diseases and is usually caused by lymphocytic thyroiditis. Lymphocytic thyroiditis is an autoimmune disease which destroys the thyroid gland. Hypothyroidism is treated medically by substituting natural hormone production with medical hormones. The aim of this study was to estimate the heritability of the hypothyroidism in Finnish Hovawart population. Research material was provided by Finnish Kennel Club and Finnish Hovawart Club. Dogs born between 1990 and 2010 were included in the study. The influence of gendre, birth year and month, size of the birth litter, breeders living area, colour and inbreeding were studied. Data was delimited in two different ways. Data 1 consisted 4953 dogs, where 107 were hypothyroid and 4846 were assumed to be healthy. In data 2, hypothyroid dogs were the same as in data 1 but only dogs used for breeding were considered as healthy (739 dogs). The χ2 test was used to evaluate the influence of individual factors. The influence of fixed effects and covariate were tested with a generalized linear model. Fixed effects were chosen by using the backward method and the applicable model was chosen by using e.g. Akaike’s information criterion, AIC. The animal model and the REML method was used in variance component analyses. Since hypothyroidism is a binary factor logit and probit models were used. For comparison, heritability was also estimated with a linear model. In data 1 colour and birth litter size were significant. In data 2 colour, birth litter size and gender were significant. Estimated heritability by logit model was 0.65 in data1 and 0.54 in data 2. When transformed to the underlying liability scale the corresponding values were 0.36 and 0.26, respectively. Heritabilities by probit model were 0.24 and 0.23 and by linear model 0.21 and 0.44 for data 1 and 2, respectively. Heritability of hypothyroidism is moderate and can be considered even as high, hence the prevalence of hypothyroidism can be decreased by breeding. However, it is not possible to exclude all hypothyroid dogs and their close relatives from breeding. Hypothyroidism can be diagnosed later when the dog has already been used for breeding. To decrease the prevalence of hypothyroidism there is a need for an appropriate tool to support breeders’ choices. Efficiency requires openness within breed and collecting and offering the data to public use.

Undernutrition and chronic micronutrient deficiency (hidden hunger) are serious problems around the world. Deficiencies in vitamin A, iron and iodine are the most common and they also cause the most health problems. In Mozambique there are micronutrient deficiencies in calcium, iron, iodine, selenium and zinc. Iodine deficiency decreases levels of thyroid hormones in the body. Thyroid hormones are in central role for example in fetal growth and child development. Furthermore, iodine deficiency causes different kinds of health problems in all age groups. Selenium deficiency can also affect levels of thyroid hormones. Selenium is needed in the activation of thyroid hormones. Also syanogenic glycosides from food can disturb thyroid metabolism. Cassava, which is commonly used food plant in Mozambique, is rich in these compounds. This master’s thesis focused on the iodine and selenium nutrition of teenage girls in Zambézia Province in Central Mozambique. I also studied how much these teenage girls use cassava as food. This master’s thesis is part of population-based cross-sectional ZANE-study. In ZANE-study diet and nutritional status of adolescent girls (15-18 years old) was studied in different types of communities in two seasons in 2010 in Quelimane, Maganja de Costa and Morrumbala. Iodine status of the girls was analysed by determining iodine concentration in urine spot samples (n=502). The selenium concentrations were determined from 522 serum samples. The thyroglobulin concentrations were also determined from the serum samples as another marker of iodine status. The results revealed that adolescent girls especially in Maganja de Costa and Morrumbala suffer from mild to moderate iodine deficiency. The median of urinary iodine concentration was 54,7 µg/l in Maganja de Costa (Q1 31,2; Q3 90,2) and 46,4 µg/l in Morrumbala (Q1 24,4; Q3 75,7). Urinary iodine concentration range 100-199 µg/l is an indicator of optimal iodine status. In Quelimane the median was 138,8 µg/l (Q1 86,8; Q3 199,4). Urinary iodine concentrations of pregnant girls were below the reference values in all areas. Serum thyroglobulin concentrations indicated also sub-optimal iodine intake. The serum selenium concentrations in the other hand were optimal in all areas. In Maganja de Costa, cassava was a staple food. In this study, iodine deficiency was observed in adolescent girls in Zambézia Province. Especially pregnant girls and their children are vulnerable group for iodine deficiency. Iodination of salt is an efficient way to increase iodine intake and iodination programmes should be made more efficient. In areas where cassava is commonly used, people should be advised to prepare it in a proper way. In this way possible disadvantages of cassava on iodine nutrition could be avoided.