Disease & Ageing

Ageing in TwinsUK

The TwinsUK cohort now has an average age of 65, with members of the cohort reaching 85 years of age.  Many of these individuals have been extensively followed over more than 15 years, using age-related phenotypes across multiple organ systems.  Comprehensive respiratory, muscular, skeletal, cardiovascular, eye, and cognitive clinical histories and biometric phenotypes have been collected, as well as, quality of life and socioeconomic measures.  Using this comprehensive dataset, Rockwood’s Frailty index of health deficits has been calculated.  In the last 2 years, study visits have incorporated measures of falls, urinary dysfunction, cognition, balance, Guralnik’s Short Physical Performance Battery, and the Fried Frailty Phenotype, as well as functional performance observed by the co-twin, and more recently oral health.  We are currently validating a questionnaire to ascertain history of delirium, an indicator of cognitive frailty, and a strong risk factor for dementia.

TwinsUK has unprecedented capacity for research into the biology of ageing through its comprehensive range of laboratory blood measures which have been assayed longitudinally.  Genotyping, including whole genome sequencing, whole blood DNA methylation markers (450K and meDIPseq), expression in whole blood, fat, skin (Muther subsample), metabolomic panels in plasma, glycosylation of IgG, and a state of the art immunophenotyping platform are available on these subjects.  In addition we already have 16S faecal gut microbiome analysis and are collecting samples for salivary, urinary, and skin microbiome analysis in these older subjects.  DNA, plasma, urine, hair saliva and skin lipidomic samples have been banked for retrospective assay of new biomarkers.   Data on putative ageing biomarkers, among them telomere length (southern blot and PCR methods), DHEAS, Apolipoproteins, sCRP are also available.

Additional value for research into ageing is garnered by the twin nature of the cohort.  Many ageing phenotypes have genetic and early life environmental influences and these are not modifiable in later life at the present time.  Sources of variance in ageing that survive correction for factors shared between twins are likely to be good targets for interventions in older adults to improve vitality in later life.

Non-exhaustive ageing phenotypes available:

1. General

Rockwood Frailty Index
Cross sectional
Fried Frailty Phenotype

2. Muscle phenotypes

Lean mass from DEXA
Lung function
Grip strength
Cross sectional
Guralnik’s SPPB, including gait speed
Nottingham Power Rig
Postural sway

3. Skeletal

Whole body DEXA

4. Cognitive/ psychometric

CANTAB battery, including Paired Associates Learning
Geriatric Depression Score, Hospital Anxiety Depression Score Anxiety Sensitivity Index
Self reported memory
Cross sectional
Deary Liewald reaction time (choice reaction time)
Verbal fluency