RT Journal Article
SR Electronic
T1 Leg length, skull circumference, and the incidence of dementia in Latin America and China; a 10/66 population-based cohort study
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 140129
DO 10.1101/140129
A1 Martin J. Prince
A1 Daisy Acosta
A1 Mariella Guerra
A1 Yueqin Huang
A1 Ivonne Z Jimenez-Velazquez
A1 Juan J. Llibre Rodriguez
A1 Aquiles Salas
A1 Ana Luisa Sosa
A1 Michael E. Dewey
A1 Maelenn M. Guerchet
A1 Zhaorui Liu
A1 Jorge J. Llibre-Guerra
A1 Matthew A. Prina
YR 2017
UL http://biorxiv.org/content/early/2017/07/08/140129.abstract
AB Background Adult leg length is influenced by nutrition in the first few years of life. Adult head circumference is an indicator of brain growth. Cross-sectional studies indicate inverse associations with dementia risk, but there have been few prospective studies.Methods Population-based cohort studies in urban sites in Cuba, Dominican Republic Puerto Rico and Venezuela, and rural and urban sites in Peru, Mexico and China. Sociodemographic and risk factor questionnaires were administered to all participants, and anthropometric measures taken, with ascertainment of incident 10/66 dementia, and mortality, three to five years later.Results Of the original at risk cohort of 13,587 persons aged 65 years and over, 2,443 (18.0%) were lost to follow-up; 10,540 persons with skull circumference assessments were followed up for 40,466 person years, and 10,400 with leg length assessments were followed up for 39,954 person years. There were 1,009 cases of incident dementia, and 1,605 dementia free deaths. The fixed effect pooled meta-analysed adjusted subhazard ratio (ASHR) for leg length (highest vs. lowest quarter) was 0.80 (95% CI, 0.66-0.97) and for skull circumference was 1.02 (95% CI, 0.84-1.25), with no heterogeneity of effect between sites (I2=0%). Leg length measurements tended to be shorter at follow-up, particularly for those with baseline cognitive impairment and dementia. However, leg length change was not associated with dementia incidence (ASHR, per cm 1.006, 95% CI 0.992-1.020), and the effect of leg length was little altered after adjusting for baseline frailty (ASHT 0.82, 95% CI 0.67-0.99). A priori hypotheses regarding effect modification by gender or educational level were not supported.Conclusions Consistent findings across settings provide quite strong support for an association between adult leg length and dementia incidence in late-life. Leg length is a relatively stable marker of early life nutritional programming, which may confer brain reserve and protect against neurodegeneration in later life through mitigation of cardiometabolic risk. Further clarification of these associations could inform predictive models for future dementia incidence in the context of secular trends in adult height, and invigorate global efforts to improve childhood nutrition, growth and development.