Background A study of pre-morbid lifestyle in 154 individuals in Australasia published in 2010 made two findings. Firstly, a passive lifestyle can be a preclinical expression of HD. Secondly, and more importantly, the higher levels of lifestyle passivity associated with those showing an earlier age at onset (AO) is in part independent of the HD mutation, suggesting that overcoming the tendency to be passive may delay onset.

Aims To undertake a replication study in a European cohort through EHDN.

Methods The Australian questionnaire was modified to reflect cultural differences and translated into Czech, French, German, Italian, Norwegian, Polish, Spanish and Swedish. Trained interviewers in 30 centres gathered data from 194 individuals with early symptomatic HD to ascertain pre-morbid lifestyle, including participation in leisure and non-leisure activities (education, occupation and domestic duties). Activities were classified as physical, intellectual or passive, and scores were generated under the categories leisure, non-leisure and total lifestyle, and data were matched with the individual’s AO and HTT CAG repeat length.

Results The mean AO was 44.4 years (range 16–71) There were strong inverse correlations between AO and both CAG repeat length (r=-0.68, p < 0.001) and a lifestyle that includes higher levels of passive activity (r = -0.22, p < 0.001), though not with higher levels of intellectual or physical activity. CAG repeat length and average pre-morbid lifestyle passivity were also strongly associated (r= + 0.32, p < 0.001). Details of the breakdown into leisure and non-leisure aspects of lifestyle and into activity data for various life stages (teens, 20s/30s and 40s/50s) will be presented.

Conclusions The data support the contention that passivity can be a pre-clinical manifestation of disease and that there may be a considerable impact of lifestyle on the age of onset.