Older Australian Twins Study

image - OATAS3
Project Main Description: 

The Older Australian Twins Study is a longitudinal, multi-centre study that investigates healthy brain ageing in older twins (65+ years). Healthy ageing is characterised by low levels of disability, high cognitive and functional capacity, and an active engagement in life. The most important ingredient of healthy ageing is a healthy brain, bereft of age-related diseases and dysfunction. Brain ageing and brain diseases are determined by multiple genetic factors that interact with environmental influences. Since identical twins share 100% of their genes, whereas non-identical twins share half the genetic information, detailed comparisons of these two groups has the potential to discover new genes involved in cognitive decline or resilience.

OATS commenced in New South Wales in January 2007, in Queensland in December 2007, and in Victoria in February 2008. Since the OATS study started we have followed our twin volunteers up every two years to check on their psychological and physical health. Participants undergo rigorous medical and cognitive function tests, with many participants’ also providing bloods samples and having a magnetic resonance imaging (MRI) scan of their brain. OATS assessed 623 participants at baseline, 450 at the 2-year follow up, and 389 completed their 4-year follow-up.

We are currently finishing an OATS imaging sub-study investigating the deposition of amyloid plaques in the brain using positron emission tomography (PET) scans. Amyloid plaques are thought to predict memory decline with age. Performing these scans in twins will help us to establish how these amyloid plaques relate to performance in memory and thinking ability. We also aim to determine if there is a genetic component, and if there are any potentially modifiable environmental factors that may be contributing to the development of the plaques. For this sub-study, 140 participants in New South Wales and Victoria were assessed and scanned.  

The OATS Study has collected a unique data set from which we can examine genetic and environmental influences on a range of ageing-related issues. In particular we are investigating links between cognitive function and brain chemistry over time which has not yet been looked at previously. The diversity and depth of our work has also allowed us to form collaborative partnerships with other twin studies around the world. These collaborations are important as we have the opportunity to further enlarge our sample size and thereby better address genetic questions, which require large samples.

Aims: 

The OATS aims to find out what influences memory and thinking as we age. It investigates environmental influences such as lifetime physical and mental activity, socioeconomic environment, and nutrition. It also investigates how biological factors such as hypertension and antioxidant levels interact with genes to influence brain ageing. Since, over time, the expression of genes varies depending on different influences in the environment, by studying twins, OATS aims to determine which influences on the ageing process are genetic, which are environmental, and how the two interact.

Participate in Our Research

Identical and non-identical twin pairs, aged 65 and older, living in New South Wales, Queensland and Victoria are eligible to participate in this research. With few exceptions, twin pairs can participate regardless of whether or not they are experiencing any memory or health problems.

In 2017 we will commence follow-up of our existing participants and invite new participants into the study. As something new, we will be doing most of the assessment using an online survey. By doing our assessment online, we will be able to include participants who live outside of major metropolitan cities. The online assessment includes answering questions about your health, lifestyle, memory and thinking and a neuropsychological assessment (the core aspect). Where feasible, participants will also be invited to provide a blood sample for analysis, and in some instances to have a MRI scan. Participants may, however, choose to complete only the core aspect of the study. Once part of the study, participants will be contacted annually and invited to take part in the study assessment again. Participants are free to opt-out of the study at any time. Please contact us for more information if you are interested in participating in this study.

For further information contact OATS on freecall 1800 81 TWIN or on email: twins@unsw.edu.au.

 

Publications

PhD Theses:

  • Lee T - Genetic and Environmental Influences on Neuropsychological Functioning in Later Life: The Older Australian Twins Study. UNSW, 2013. Supervisor: Perminder Sachdev, UNSW
  • Batouli SAH - Genetic and Environmental Influences on Brain Structure and Biochemistry in the Elderly: Data from the Older Australian Twins Study. UNSW, 2013. Supervisors: Perminder Sachdev, Julian Trollor and Wei Wen, UNSW

 

Masters Theses:

  • Kanchibhotla, SC - Genetics of the White Matter Integrity in the Ageing Brain. UNSW, 2015. Supervisor: Karen Mather, UNSW.

 

Honours Theses:

  • Duckworth T - Heritability of Excessive Daytime Sleepiness and Associated Inflammation in Older Australian Twins. Central Queensland University, 2012. Supervisors: Julian Trollor, UNSW and Greg Roach, CQU.
  • Lazarus J - Examination of DNA Methylation in the APOA1 Gene. UNSW, 2013. Supervisors: Karen Mather and Johhn Kwok, UNSW

 

Journal publications:

1.    Sachdev PS, Lammel A, Trollor JN, Lee T, Wright MJ, Ames D, et al. A comprehensive neuropsychiatric study of elderly twins: the Older Australian Twins Study. Twin Res Hum Genet. 2009;12(6):573-582.
2.    Lee T, Henry JD, Trollor JN, Sachdev PS. Genetic influences on cognitive functions in the elderly: a selective review of twin studies. Brain Research Reviews. 2010;64(1):1-13.
3.    Sachdev PS, Lee T, Lammel A, Crawford J, Trollor JN, Wright MJ, et al. Cognitive functioning in older twins: the Older Australian Twins Study. Australas J Ageing. 2011;30 Suppl 2:17-23.
4.    Batouli SA, Sachdev PS, Wen W, Wright MJ, Suo C, Ames D, et al. The heritability of brain metabolites on proton magnetic resonance spectroscopy in older individuals. NeuroImage. 2012;62(1):281-289.
5.    Lee T, Crawford JD, Henry JD, Trollor JN, Kochan NA, Wright MJ, et al. Mediating effects of processing speed and executive functions in age-related differences in episodic memory performance: a cross-validation study. Neuropsychology. 2012;26(6):776-784.
6.    Lee T, Mosing MA, Henry JD, Trollor JN, Ames D, Martin NG, et al. Genetic influences on four measures of executive functions and their covariation with general cognitive ability: the Older Australian Twins Study. Behavior Genetics. 2012;42(4):528-538.
7.    Lee T, Mosing MA, Henry JD, Trollor JN, Lammel A, Ames D, et al. Genetic influences on five measures of processing speed and their covariation with general cognitive ability in the elderly: the older Australian twins study. Behavior Genetics. 2012;42(1):96-106.
8.    Sachdev P, Trollor J, Lammel A, Lee T, Wright M, Ames D, et al. Recent findings from the Older Australian Twins Study (OATS). Alzheimer's & Dementia. 2012;8(4):P675.
9.    Sachdev PS, Lee T, Wen W, Ames D, Batouli AH, Bowden J, et al. The contribution of twins to the study of cognitive ageing and dementia: the Older Australian Twins Study. Int Rev Psychiatry. 2013;25(6):738-747.
10.    Batouli SA, Sachdev PS, Wen W, Wright MJ, Ames D, Trollor JN. Heritability of brain volumes in older adults: the Older Australian Twins Study. Neurobiology of Aging. 2014;35(4):937 e935-918.
11.    Batouli SA, Trollor JN, Wen W, Sachdev PS. The heritability of volumes of brain structures and its relationship to age: a review of twin and family studies. Ageing Res Rev. 2014;13:1-9.
12.    Kanchibhotla SC, Mather KA, Thalamuthu A, Zhuang L, Schofield PR, Kwok JB, et al. Genetics of microstructure of the corpus callosum in older adults. PLoS One. 2014;9(12):e113181.
13.    Lee T, Lipnicki DM, Crawford JD, Henry JD, Trollor JN, Ames D, et al. Leisure activity, health, and medical correlates of neurocognitive performance among monozygotic twins: the Older Australian Twins Study. J Gerontol B Psychol Sci Soc Sci. 2014;69(4):514-522.
14.    Lee T, Sachdev P. The contributions of twin studies to the understanding of brain ageing and neurocognitive disorders. Curr Opin Psychiatry. 2014;27(2):122-127.
15.    Boraxbekk CJ, Ames D, Kochan NA, Lee T, Thalamuthu A, Wen W, et al. Investigating the influence of KIBRA and CLSTN2 genetic polymorphisms on cross-sectional and longitudinal measures of memory performance and hippocampal volume in older individuals. Neuropsychologia. 2015;78:10-17.
16.    Davies G, Armstrong N, Bis JC, Bressler J, Chouraki V, Giddaluru S, et al. Genetic contributions to variation in general cognitive function: a meta-analysis of genome-wide association studies in the CHARGE consortium (N=53949). Molecular Psychiatry. 2015;20(2):183-192.
17.    Hibar DP, Stein JL, Renteria ME, Arias-Vasquez A, Desrivieres S, Jahanshad N, et al. Common genetic variants influence human subcortical brain structures. Nature. 2015;520(7546):224-229.
18.    Lazarus J, Mather KA, Armstrong NJ, Song F, Poljak A, Thalamuthu A, et al. DNA methylation in the apolipoprotein-A1 gene is associated with episodic memory performance in healthy older individuals. J Alzheimers Dis. 2015;44(1):175-182.
19.    Mather KA, Armstrong NJ, Wen W, Kwok JB, Assareh AA, Thalamuthu A, et al. Investigating the genetics of hippocampal volume in older adults without dementia. PLoS One. 2015;10(1):e0116920.
20.    Willemsen G, Ward KJ, Bell CG, Christensen K, Bowden JL, Dalgard C, et al. The Concordance and Heritability of Type 2 Diabetes in 34,166 Twin Pairs From International Twin Registers: The Discordant Twin (DISCOTWIN) Consortium. Twin Res Hum Genet. 2015;18(6):762-771.
21.    Adam HHH. Novel genetic loci underlying human intracranial volume identified through genome-wide association. Nature Neuroscience. 2016;19(12):1569-1582.
22.    Guadalupe T. Human subcortical brain asymmetries in 15,847 people worldwide reveal effects of age and sex. Brain Imaging and Behavior. 2016;epub ahead of print.
23.    Lupton MK, Strike L, Hansell NK, Wen W, Mather KA, Armstrong NJ, et al. The effect of increased genetic risk for Alzheimer's disease on hippocampal and amygdala volume. Neurobiology of Aging. 2016;40:68-77.
24.    Mather KA, Thalamuthu A, Oldmeadow C, Song F, Armstrong NJ, Poljak A, et al. Genome-wide significant results identified for plasma apoH levels in middle-aged and older adults. Scientific Reports. 2016;6:23675.
25.    Sachdev PS, Thalamuthu A, Mather KA, Ames D, Wright MJ, Wen W, et al. White matter hyperintensities are under strong genetic influence. Stroke. 2016;47(6):1422-1428.
26.    Wen W, Thalamuthu A, Mather KA, Zhu W, Jiang J, de Micheaux PL, et al. Distinct genetic influences on cortical and subcortical brain structures. Scientific Reports. 2016;6:32760.
27.    Armstrong NJ, Mather KA, Thalamuthu A, Wright MJ, Trollor JN, Ames D, et al. Aging, exceptional longevity and comparisons of the Hannum and Horvath epigenetic clocks. Epigenomics. 2017;9(5):689-700.
28.    Brouwer RM, Panizzon MS, Glahn DC, Hibar DP, Hua X, Jahanshad N, et al. Genetic influences on individual differences in longitudinal changes in global and subcortical brain volumes Results of the ENIGMA plasticity working group. Human Brain Mapping. 2017.
29.    Garton FC, Benyamin B, Zhao Q, Liu Z, Gratten J, Henders AK, et al. Whole exome sequencing and DNA methylation analysis in a clinical amyotrophic lateral sclerosis cohort. Molecular Genetics & Genomic Medicine. 2017;5(4):418-428.

Staff

Older Australian Twins Study NSW
Study Coordinator
Research Assistant
Administrative Assistant
 
Older Australian Twins Study QLD
Research Assistant
Natalie Garden
 
Older Australian Twins Study VIC
Research Assistant
Christel Lemmon
 
Older Australian Twins Study Investigators
David Ames
Bernhard Baune
Teresa Lee
Nick Martin
Karen Mather
Christopher Rowe
Perminder Sachdev
Katherine Samaras
Peter Schofield
Wei Wen
Margie Wright
 
Older Australian Twins Study Collaborators & Researchers
Lesley Campbell
Michelle Lupton
Julia Muenchhoff
Project Status: 
Current
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