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Dissertations

On this page, you will find summaries of the latest dissertations from Folkhälsan Research Center, providing insights into recent research. Further down, you will also find a comprehensive list of past dissertations, including links to the full texts.
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Cerebral small vessel disease and stroke in type 1 diabetes – The impact of blood pressure, haptoglobin genotype, and diabetic retinopathy

Marika Eriksson: The results suggest that cerebrovascular disease in type 1 diabetes is linked to microvascular damage and that the health of the eye’s blood vessels may reflect the health of the brain’s blood vessels.

Marika Eriksson: Cerebral small vessel disease and stroke in type 1 diabetes – The impact of blood pressure, haptoglobin genotype, and diabetic retinopathy

Cerebrovascular disease, such as stroke, is a severe complication of type 1 diabetes, with a high risk of disability and mortality. It is not fully clear how cerebrovascular complications develop, but diabetes is suggested to damage the brain’s small vessels similarly to other diabetic microvascular damage.
 
This study aimed to assess factors associated with early signs of cerebrovascular brain damage in asymptomatic individuals with type 1 diabetes, as well as risk markers for the development of stroke in these individuals.
 
Our results showed that cerebral small vessel disease is associated with elevated nocturnal blood pressure in type 1 diabetes. We also found cerebral small vessel diseases to be more common with increasing severity of diabetic eye disease and that severe diabetic eye disease marked an increased risk of having a stroke. 

The results suggest that cerebrovascular disease in type 1 diabetes is linked to microvascular damage and that the health of the eye’s blood vessels may reflect the health of the brain’s blood vessels.

Marika Eriksson: Cerebral small vessel disease and stroke in type 1 diabetes – The impact of blood pressure, haptoglobin genotype, and diabetic retinopathy. 2025.

Sleep habits of Finnish preschoolers: Associations with diet and weight

Anna Abdollahi: Children with a later chronotype at preschool age were associated with greater weight gain over the eight-year follow-up period.

Anna Abdollahi: Sleep habits of Finnish preschoolers: Associations with diet and weight

Having a later chronotype often increases the risk of circadian misalignment, as social demands often conflict with internal biological clocks. Among adolescents and adults, a later chronotype has been associated with less healthy sleep patterns, poorer diet quality, increased weight status, and reduced overall well-being. However, little research has focused on younger children, leaving it unclear when these associations begin to develop.

Using data from the DAGIS project, we employed novel, data-driven sleep estimation methods with actigraphy data to assess several sleep measures, including chronotype.

While children with a later chronotype were not associated with higher weight outcomes during preschool age, they were associated with less healthy diet quality, including lower vegetable and higher sugary food consumption. Furthermore, children with a later chronotype at preschool age were associated with greater weight gain over the eight-year follow-up period.

In conclusion, our findings suggest that preschool age may be a critical period when children vulnerable to circadian misalignment potentially begin to experience its negative effects. More research is needed to understand sleep, diet, and weight trajectories in children and the early role of circadian misalignment in weight development.

My dissertation also explored the associations between other sleep measures (duration, timing, quality) with diet (energy intake, macronutrient intake, and food consumption), and weight outcomes.

Anna Abdollahi: Sleep habits of Finnish preschoolers: Associations with diet and weight. 2025.

 

Frailty and functioning as determinants of healthcare use

Jenni Ikonen: We found that frailty was associated with greater specialized and primary healthcare service use. Furthermore, frailty and its faster progression rate were associated with increased medical imaging service use and costs.

Jenni Ikonen: Frailty and functioning as determinants of healthcare use

The aging global population is creating new demands for healthcare systems. Understanding factors that drive healthcare use is essential for planning preventative measures and adapting the services to meet the needs of the aging populations. Frailty, characterized by vulnerability to stressors and impaired recovery, is proposed to explain health differences among older adults, while maintaining functioning is central to healthy aging. Therefore, we aimed to investigate whether frailty and functioning would be associated with healthcare use.

We found that frailty was associated with greater specialized and primary healthcare service use. Furthermore, frailty and its faster progression rate were associated with increased medical imaging service use and costs. Participants with poorer physical functioning had higher utilization rates of specialized healthcare services compared to participants with better functioning. Poorer mental functioning, in turn, was associated with a higher number of first outpatient visits. In conclusion, public health interventions should be considered to prevent frailty and support functioning among aging populations.

Jenni Ikonen: Frailty and functioning as determinants of healthcare use. 2024.

Estrogen biosynthesis in subcutaneous and visceral adipose tissue in women

Natalia Hetemäki: We found that considerable amounts of estrogens were produced in fat already before menopause. After menopause, the role of visceral adipose tissue in the production of estrogens was highlighted.

Natalia Hetemäki: Estrogen biosynthesis in subcutaneous and visceral adipose tissue in women 

Adipose tissue, or fat tissue, is important in the production of sex steroids like estrogens and androgens, especially after menopause. The distribution of adipose tissue in women changes over the course of their reproductive life – at menopause, the relative amount of visceral compared to subcutaneous adipose tissue increases, and this leads to an increased risk of metabolic disorders such as cardiovascular disease and type of 2 diabetes. Menopausal hormone therapy seems to mitigate these changes.

We studied changes taking place in the biosynthesis of estrogens in subcutaneous and visceral adipose tissue in women before and after menopause. We also studied how the production of estrogens and androgens in fat is affected by the use of menopausal hormone therapy.

We found that considerable amounts of estrogens were produced in fat already before menopause. After menopause, the role of visceral adipose tissue in the production of estrogens was highlighted. Users of menopausal hormone therapy had high tissue to serum concentrations of estrogens and increased local estrogen-to-androgen ratios in adipose tissue compared to women without hormone therapy. These changes could play a role in the preventive effect that menopausal hormone therapy has on menopause-associated visceral adiposity.

Natalia Hetemäki: Estrogen biosynthesis in subcutaneous and visceral adipose tissue in women. 2024.

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Genetic and Functional Studies of Ultra-Rare Diseases

Johanna Lehtonen: A striking binding pattern was unraveled: the ends of the nebulin super-repeat region bound strongly to filamentous actin, whereas the central part bound weakly.

Johanna Lehtonen: Genetic and Functional Studies of Ultra-Rare Diseases 

In my doctoral thesis, I investigated the genetic inheritance of ultra-rare diseases in twelve families using different high-throughput sequencing (HTS) methods. Of those methods, a technology called linked-read sequencing was studied in more detail.

The study showed that linked-read sequencing can solve the haplotype information (in other words, the information which set of variants are inherited from each parent) even for very large muscle disease genes if the DNA meets quality standards.

These different sequencing strategies resulted in identifying a molecular genetic diagnosis in four families when variants in ACTA1, CCDC88A, MYH3, and TPM3 genes were identified. The thesis work also included functional laboratory studies: the disease-causing mechanisms of the identified CCDC88A variants were evaluated using patient cells.

Additionally, the binding ability of wild-type nebulin and actin muscle sarcomere proteins was investigated. A striking binding pattern was unraveled: the ends of the nebulin super-repeat region bound strongly to filamentous actin, whereas the central part bound weakly.

Johanna Lehtonen: Genetic and Functional Studies of Ultra-Rare Diseases. 2024.

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Feline personality and problematic behaviour – Associations with demographic, genetic, and environmental factors

Salla Mikkola: The most important factors associating with the problematic behaviour were cat's breed and personality traits, especially fearfulness and sociability.

Salla Mikkola: Feline personality and problematic behaviour – Associations with demographic, genetic, and environmental factors 

Like dogs, cats can have problematic behaviour. Problematic behaviour is an important subject to study as it can decrease the welfare of both the owner and the cat. We targeted four common problems in cats and studied which demographical, personality and environmental factors associate with them. In addition, we investigated the structure of personality in cats and validated the data with multiple methods.

The results show that the problematic behaviours are complex and affected by various variables. The most important factors associating with the problematic behaviour were cat's breed and personality traits, especially fearfulness and sociability. The gathered data was proven to be valid and reliable.

Salla Mikkola: Feline personality and problematic behaviour – Associations with demographic, genetic, and environmental factors. 2024.

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Biomarkers of the Gut Fungal and Bacterial Composition in Inflammatory Bowel Disease

Rebecka Ventin-Holmberg: The results showed that treatment responses could be accurately predicted even before treatment initiation, and that gut microbiota health improved during successful treatment.

Rebecka Ventin-Holmberg: Biomarkers of the Gut Fungal and Bacterial Composition in Inflammatory Bowel Disease

Research on biomarkers of the gut microbiota may support the important development of precision and personalization of treatment and indication of disease predisposition. Here biomarkers to predict inflammatory bowel disease treatment response were examined and inflammatory-linked biomarkers were investigated from the fungal microbiota of antibiotic-treated infants.

The results showed that treatment responses could be accurately predicted even before treatment initiation, and that gut microbiota health improved during successful treatment. Additionally, significant changes were observed in the fungal gut microbiota of infants exposed to antibiotics.

Rebecka Ventin-Holmberg: Biomarkers of the gut fungal and bacterial composition in inflammatory bowel disease. 2024.

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Simple devices for single-cell trapping and droplet digital PCR

Pinja Elomaa: The study presents promising advancements in droplet technology, offering cost-efficient and fast solutions for single-cell capturing and nucleic acid amplification, with potential future commercial applications in various settings, from field laboratories to clinical facilities.

Pinja Elomaa: Simple devices for single-cell trapping and droplet digital PCR

Droplet technology holds immense potential in various biomedical applications, from single-cell techniques to ddPCR, wherein samples are compartmentalized into numerous droplets housing individual cells or RNA/DNA strands.

Despite existing advanced devices, many are costly and complex. This study focused on advancing droplet-based systems for biomedical research and diagnostics, aiming to develop accessible and portable chips suitable for rapid diagnostics.

Experimental results demonstrate efficacious isolation of single cells as well as isolation and amplification of RNA strands within droplets, particularly showcasing efficient nucleic acid amplification of the SARS-CoV-2 virus using the isothermal amplification reaction, SIBA (Aidian).

Overall, the study presents promising advancements in droplet technology, offering cost-efficient and fast solutions for single-cell capturing and nucleic acid amplification, with potential future commercial applications in various settings, from field laboratories to clinical facilities.

Pinja ElomaaSimple devices for single-cell trapping and droplet digital PCR. 2024.

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Growth, puberty, gynecological health, and fertility in women with APECED

Viivi Saari: We showed that subjects with APECED have progressive growth impairment through prepuberty until the attainment of adult height.

Viivi Saari: Growth, puberty, gynecological health, and fertility in women with APECED

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) is a rare genetic disorder arising from mutations in the autoimmune regulator (AIRE) gene.

AIRE participates in the regulation of autoimmunity. Clinical presentation of APECED is variable, with over 20 different disease manifestations recognized. In women, primary ovarian insufficiency is one of the most common endocrine manifestations.

Our primary objectives were to investigate growth patterns of patients with APECED from birth until the attainment of adult height and to explore effects of APECED on pubertal development, sexual health, and fertility in women with APECED.

We showed that subjects with APECED have progressive growth impairment through prepuberty until the attainment of adult height. Primary ovarian insufficiency often develops shortly after puberty leading to sex hormone deficiencies and a decline in fertility.

Pregnancies in women with APECED are rare, but pregnancy outcomes are usually favourable for both the mother and the infant.

Viivi Saari: Growth, puberty, gynecological health, and fertility in women with APECED. 2024.

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Cardiometabolic health and morbidity in offspring of women with type 1 diabetes

Cedric Korpijaakko: The findings from this thesis suggest that exposure to type 1 diabetes during fetal development might affect long-term health in offspring.

Cedric Korpijaakko: Cardiometabolic health and morbidity in offspring of women with type 1 diabetes

It has been suggested that exposure to maternal diabetes in utero may program the development of cardiometabolic diseases in offspring during adulthood.

The aim of this doctoral thesis was to assess whether maternal type 1 diabetes affects cardiometabolic health in offspring, by investigating prescription drug purchases and by evaluating clinical signs of cardiometabolic diseases during young adulthood.

From the age of seven, we observed that offspring of women with type 1 diabetes purchased significantly more prescription drugs for several indications than offspring of women without diabetes, with increased purchases of prescription drugs used in the treatment of diabetes and cardiovascular disease.

We could not find any differences between offspring of women with type 1 diabetes and offspring of women without diabetes for anthropometric measures or glucose or lipid concentrations in young adulthood.

A new finding was increased arterial stiffness in young adult offspring of women with type 1 diabetes compared to offspring of women without diabetes, while other metrics of cardiovascular disease remained similar.

The findings from this thesis suggest that exposure to type 1 diabetes during fetal development might affect long-term health in offspring.

Cedric Korpijaakko: Cardiometabolic health and morbidity in offspring of women with type 1 diabetes. 2024.

List of dissertations

2025

Marika Eriksson: Cerebral small vessel disease and stroke in type 1 diabetes – The impact of blood pressure, haptoglobin genotype, and diabetic retinopathy. 2025.

Anna Abdollahi: Sleep habits of Finnish preschoolers: Associations with diet and weight. 2025.

2024

Jenni Ikonen: Frailty and functioning as determinants of healthcare use. 2024.

Natalia Hetemäki: Estrogen biosynthesis in subcutaneous and visceral adipose tissue in women. 2024.

Johanna Lehtonen: Genetic and Functional Studies of Ultra-Rare Diseases. 2024.

Salla Mikkola: Feline personality and problematic behaviour – Associations with demographic, genetic, and environmental factors. 2024.

Rebecka Ventin-Holmberg: Biomarkers of the gut fungal and bacterial composition in inflammatory bowel disease. 2024.

Pinja ElomaaSimple devices for single-cell trapping and droplet digital PCR. 2024.

Viivi Saari: Growth, puberty, gynecological health, and fertility in women with APECED. 2024.

Cedric Korpijaakko: Cardiometabolic health and morbidity in offspring of women with type 1 diabetes. 2024.

Kaija Nissinen: Varhaiskasvatusikäisten lasten ruoankäyttö, ravintoaineiden saanti ja stressibiomarkkerit. 2024.

2023

Joonatan BorchersPrimary adrenal insufficiency: epidemiological aspects and associating features in APECED. 2023.

Perttu LiuskaMyocilin and the genetics of open-angle glaucoma in Finland. 2023.

Jenny WadénsRAGE and genetic variations at the HLA locus in type 1 diabetes, its complications, and mortality. 2023.

Niina-Maria NissinenSecondary disabilities in Finnish youth with prenatal substance exposure. 2023. 

Mari LaaksoFlourishing students and families – Enhancing well-being of adolescents and families through positive psychology interventions. 2023.    

Maria Enlund-CerulloVitamin D metabolism in early childhood; associations with genetic variants and biomarkers. 2023. 

Eduard Daura SarrocaRole of cystatin B in the regulation of histone H3 tail proteolysis in the mouse brain : study on the molecular mechanisms of progressive myoclonus epilepsy type 1. 2023.

Riikka PajulahtiIndividual perspective on the world of food: Studies on temperament, food environment, and diet among children. 2023.            

Elina TuovinenPhenotypic and mechanistic clues to inborn errors of immunity. 2023.

Mia ErikssonMelancholia or Not; The Mysterious Differences in Depression: A Study of Pathophysiological Differences Between Depressive Subtypes – Findings from The Helsinki Birth Cohort Study. 2023

Sini SulkamaRisk factors of canine ADHD-like and repetitive behaviour. 2023

2022

Marjo NuottamoMigraine with aura – genetic susceptibility variants. 2022

Emma DahlströmObesity and complications in type 1 diabetes  – a genetic and clinical perspective. 2022

Lydia SagathCopy number variants in genes causing neuromuscular disorders. 2022

Claudia OttkaMetabolomics in canine physiology and pathophysiology: A nuclear magnetic resonance (NMR) spectroscopy method for dogs. 2022

Fanny Jansson SiegfriedsIncidence, progression, and regression of diabetic kidney disease in type 1 diabetes. 2022

Julia NiskanenThe genetic background of five canine models of rare human disease. 2022

Sohvi LommiSweet treat consumption in school-aged children – Relationships to excess weight, dental caries and saliva microbiota. 2022 

2021             

Petra LoidGenetic determinants of severe childhood-onset obesity. 2021

Stefanie Hägg-HolmbergIncidence, risk factors, and prognosis of stroke in people with type 1 diabetes. 2021

Nicolae Mircea PanduruUrinary biomarkers for the prediction of diabetic nephropathy, cardiovascular disease and mortality in individuals with type 1 diabetes.

2021

Johan Rasmus Alexander SimonsenBacterial infections in type 1 diabetes and their association with micro- and macrovascular complications. 2021

Jarno KettunenThe FINNMODY study : clinical characterization of maturity-onset diabetes of the young (MODY) in Finland. 2021

Anna SyreeniGenetic aspects of type 1 diabetes and its complications. 2021

Mridul JohariMolecular Genetics of Inclusion Body Myositis and Late-Onset Rimmed-Vacuolar Distal Myopathy. 2021

2020           

Riikka SarviahoGenetics of Canine Epilepsy and Anxiety. 2020

Salla VälipakkaImproving CNV detection from short-read MPS data in neuromuscular disorders. 2020

Janne PurhonenMolecular, metabolic, and therapeutic aspects of respiratory complex III deficiency: Bcs1l mutant mice as an experimental model. 2020

Milla SalonenComplex traits, complex results: The genetic, demographic, and environmental factors of cat and dog behaviour. 2020

Heidi Tikkanen-DolencPhysical activity and Type1 diabetes: Impact on diabetic complications. 2020

Meharji ArumilliBioinformatic approaches to facilitate canine disease genetics and genomics. 2020

Maija FeodoroffRole of alcohol and smoking for vascular complications in Type 1 diabetes. 2020 

2019           

Jayasimman RajendranInterventions to improve mitochondrial function in a mouse model of GRACILE syndrome, a complex III disorder. 2019

Svetlana VakkilainenImmunodeficiency in cartilage-hair hypoplasia: Correlation with pulmonary disease, infections and malignancy. 2019

Jenni LaitilaElucidating nebulin expression and function in health and disease

Maria KaukonenGenetics of three canine eye disorders. 2019

2018             

Riikka MäkitieSkeletal and extra-skeletal characteristics of WNT1 osteoporosis. 2018

Mari MuurinenSilver-Russell syndrome and human genetics: genetic and epigenetic studies. 2018

Jenni PuurunenMetabolomic characterization of canine behavioural disorders: fearfulness and hyperactivity/impulsivity. 2018

2017

Christopher L. FogartyBiological factors involved in the modulation of bacterial endotoxin-mediated inflammation in type 1 diabetes. 2017

Satu Massinen: Specific readning disorder: cellular and neurodevelopmental functions of susceptibility genes. 2017

Inken Körber: Microglial dysfunction in Cstb-/- mice, a model for the neurodegenerative disorder progressive myoclonus epilepsy of Unverricht-Lundborg type, EPM1. 2017 

2016

Elviira Lehto: The associations between schoolchildren s fruit and vegetable intake and psychosocial factors – shaped by gender, socioeconomic background and an intervention. 2016

Anni EviläNovel genetic defects in titinopathies and other muscular dystrophies. 2016 

Mikko MuonaIdentification of new genetic syndromes with epilepsy by whole-exome sequencing. 2016

Hanna Paatela: Role of dehydroepiandrosterone in high-density lipoprotein-mediated vasodilation and in adipose tissue steroid biosynthesis. 2016

Mariann LasseniusBacterial endotoxins in type 1 diabetes. 2016