PI of Betula biological sample collection: Prof. Rolf Adolfsson, Umeå University.
Within the Betula study, a comprehensive collection of biological samples has been gathered that enables advanced analyses of DNA, serum and plasma. The collection of biological samples for research purposes started in 1988 at the Betula study's initial test round T1 (1988-1990) and has continued to be collected every five years in conjunction with the test round T2, T3, T4, T5 until T6, which was completed in 2014. The objective of the sample collection has been to create the opportunity to study biological parameters in relation to a wide spectrum of phenotypic and cognitive data, including the underlying factors for the development of dementia. The repeated sampling rounds have resulted in quite unique opportunities to conduct longitudinal studies focusing on various genetic, biochemical and molecular biological aspects associated with health, aging, memory functions and dementia.
The participants in the Betula study have been randomly selected from the population of the municipality of Umeå and are considered as fairly representative of the general population. In research where specific diseases such as cancer, affective disorders, schizophrenia etc. are under study, populations like Betula can be highly valuable to use as controls for comparison between diseased and healthy groups, so called case-control studies.
The Betula study comprises about 4,450 participants whereof as many as over 4,300 persons have provided blood for research purpose at one occasion or more. The donation of research samples is voluntary and study participants who agree to contribute with research samples have to sign a written consent. The blood samples are stored at -80 C in the form of serum (T1), peripheral blood, serum, plasma (T2, T3) or buffy coat, serum, plasma (T4, T5, T6). For a significant proportion of the longitudinal samples, DNA has been extracted for the purpose of e.g. studies of telomere dynamics and DNA-methylation.
Up to October 2015, more than 70 publications with results based on samples from the Betulas biological sample collection have been published in scientific journals. A full list of Betula publications are listed at the Betula website.
Conducted and published studies involving biological samples
Candidate genes and biochemical parameters have been studied in relation to cognition and dementia (Nilsson et al., 1996; Van Langhem et al., 1998; Sundström et al., 2004; de Frias et al., 2004; de Frias et al., 2005; Nilsson et al., 2006; Sundström et al., 2007a; Sundström et al., 2007b; de Frias et al., 2007; Sternäng et al., 2009; Wikgren et al., 2012: Lövheim et al., 2014; Mousavi et al., 2014).
A number of papers have been published in which certain genes have been studied in relation to brain morphology and function (Persson et al., 2006; Lind et al., 2006a; Lind et al., 2006b; Lind et al., 2006c; Persson et al., 2008; Kauppi et al., 2011; Wikgren et al., 2012; Kauppi et al., 2013; Wikgren et al., 2014; Fernandes et al., 2014).
The dopamine- and serotonin systems in relation to specific personality traits have been assessed. (Van Gestel et al., 2002; Melke et al., 2003)
Furthermore, gender aspects (hormones) have been studied in various aspects relative to cognition and self-perceived health (Yonker et al., 2003; Yonker et al., 2005; Yonker et al., 2006; Rolandsson et al., 2007; Thilers et al., 2009; Lekander et al., 2011; Andreasson et al., 2012).
In addition, parts of the Betula population have formed control group in several studies where differences between diseased and healthy groups have been studied.
Ongoing studies involving biological samples (responsible senior researcher(s) in parentheses).
Telomere dynamics in a normal population (Degerman, Adolfsson)
Longitudinal aspects of telomeres in relation to memory and dementia (Degerman, Nyberg, Adolfsson)
Longitudinal aspects of DNA-methylation in relation to memory and dementia (Degerman, Nyberg, Adolfsson)
Telomeres, cognition and dementia in a genomic perspective (Adolfsson et al)
Telomeres in relation to structural and functional brain imaging (MRI/fMRI) (Nyberg, Adolfsson)
Personality, cognition and genes (Rönnlund, Adolfsson)
Metabolomics for biomarker discovery in neurodegenerative diseases (Öhman et al)