Genetic and environmental hypertension risk factors in the TAMRISK cohort

Event start date
Event start time
12.00
Place

Arvo building, Jarmo Visakorpi auditorium, address: Arvo Ylpön katu 34.

Doctoral defence of Lic.Med. Kirsi Määttä

Genetic and environmental hypertension risk factors in the TAMRISK cohort

The field of science of the dissertation is Medical Biochemistry.

The opponent is professor emeritus Heikki Vapaatalo (University of Helsinki). Professor Seppo Nikkari acts as the custos.

The language of the dissertation defence is Finnish.

Genetic and environmental hypertension risk factors

Hypertension is one of the most important risk factors for cardiovascular diseases. It forms a significant burden for healthcare and it is a major health problem worldwide. Blood pressure is affected by genetic and environmental factors such as overweight, salt intake and exercise. Periodic health examinations (PHE) aim in the early diagnosis of disease and they are part of the preventive medicine for chronic disease. Blood pressure rises due to age, but genetic factors may cause hypertension already at young age. Although genetic background of hypertension has been widely studied, majority still remains unfound. Studies suggest a complex polygenic inheritance of hypertension and the effect of one gene is minor. Heritability of blood pressure is approximated as 30-50 %.

In this study three candidate genes affecting blood pressure are presented. Serine-threonine kinase coding gene STK39 takes part in regulation of sodium and potassium excretion in the kidneys. Gene SLC7A1 polymorphism changes L-arginine transport and affects vascular tone. Third gene of this study was HFE, which acts in body iron uptake. According to the previous studies these three genes could be associated with hypertension. This association has not been studied previously in the Finnish cohort. In addition the role of periodic health examinations for body mass index and blood pressure during 15 years of follow-up was studied.

The study population was TAMRISK, Tampere adult population risk study, cohort. The data for TAMRISK was collected from the periodic health examinations and it included questionnaire, visit to a nurse and baseline measurements. The study was prospective and periodic health examinations were done for 50 years old Tampere citizens. There were approximately 445 cases and 770 controls, depending on succeeded DNA analysis of each work. DNA samples were collected, DNA was restricted and copied by polymerase chain reaction PCR using either allelic specific primers or using restrictionenzymeanalysis.

This study indicated that rs6749447 polymorphism in STK39 was associated with hypertension for 50 years old Finnish men and women. There was no association with polymorphism rs41318021 in SLC7A1 with hypertension. It was anyhow seen that carriers of this polymorphism had higher diastolic blood pressure at the ages of 35 and 40 years old. HFE gene polymorphism rs1799945 was associated with higher risk for hypertension. Blood pressure was significantly higher among polymorphism carriers at the age of 35 and 40 years old. There was no difference among 45 years or 50 years old men and women. The effect of periodic health examinations PHE was not as efficient as expected on subjects already slightly overweight at baseline. PHE could not prevent the weight gain or blood pressure rise during the follow-up time.

In this study two genes associating with hypertension in a Finnish cohort was found. In the future genetic background of hypertension can be utilized in selecting blood pressure medication. High blood pressure rises the risk for cardiovascular diseases and therefore genes causing hypertension already at young age are important to find.                                                                                   

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The dissertation is published in the publication series of Acta Universitatis Tamperensis; 2438, Tampere University Press, Tampere 2018. The dissertation is also published in the e-series Acta Electronica Universitatis Tamperensis; 1951, Tampere University Press 2018.

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