Growth matters

The search for risk factors for dementia is of great importance. This knowledge will help people to make efforts for prevention or to plan self-care in old age.

A new study has provided evidence that a man's height at a young age may be one of the risk factors for senile dementia.

The idea of such a relationship is not new: previous studies have suggested that height may be a risk factor for dementia, but they did not take into account genetic, environmental and other factors that may be associated with both growth and dementia.

Researchers from the University of Copenhagen analyzed data from 666,333 Danish men (average age 22) born between 1939 and 1959, including 70,608 brothers and 7,388 twins, from Danish national registries and databases. They found a total of 10,599 men who later developed dementia.

Adjusted analysis of this group showed that the risk of developing dementia decreases by about 10% for every 6 cm of height in people above average height. When the researchers took into account the potential role of intelligence or education, the association between height and dementia risk was only slightly reduced, but was still present.

Risk factor (HR) with a 95% confidence interval (gray) of the relationship between a standardized assessment (z-score) of a man's growth at a young age and dementia in old age. Source: article in bioRxiv.

The relationship between height and dementia did not disappear when siblings of different heights were compared, suggesting that heredity and family habits do not explain the higher risk of dementia in short men. The analysis of the twins also confirmed the correlation of growth and dementia, although the results for this group were less reliable.

The advantage of this study is that it takes into account the potential importance of education and intelligence for the risk of senile dementia in young men, or the so–called cognitive reserve - the brain's ability to improvise and solve problems that arise in everyday life. The authors believe that statistical accounting of education and intelligence reduces the likelihood that the link between growth and dementia is insignificant and is explained only by cognitive reserve.

A major drawback of the study is the uncertainty as to whether the findings can be applied to women, as previous studies of potential gender differences in the relationship between height and dementia are mostly inconclusive.

Article by T.S.H.Jørgensen et al. Body height in young adult men and risk of dementia later in adult life is published in bioRxiv.

Aminat Adzhieva, portal "Eternal Youth" http://vechnayamolodost.ru based on eLife: Study suggests taller young men may have lower dementia risk.