TY - JOUR

T1 - Body mass index in young adulthood and risk of subsequent dementia at different levels of intelligence and education in Danish men

AU - Osler, Merete

AU - Okholm, Gunhild Tidemann

AU - Sørensen, Thorkild I. A.

AU - Jorgensen, Terese Sara Hoj

PY - 2020

Y1 - 2020

N2 - The risk of dementia seems to be established already early in life, which leads to the question if overweight early in life is an important risk factor for dementia as it appears to be later in life. We examined the association between body mass index (BMI) at entry to adult life and subsequent risk of dementia in men and assessed whether the relationship differed by levels of intelligence and education. The study population consisted of 377,598 Danish men born 1939-1959 with measures of height, weight, intelligence test score (ITS), and educational level (EL) at conscript board examinations around the age of 19 years. Dementia outcomes were obtained from National Patient and Prescription Registries between 1969 and 2016. The association between BMI and dementia was analysed using Cox proportional hazard regression including interactions between BMI and ITS and EL, respectively. During the follow-up through age 77 years, 6144 (1.6%) developed dementia. The frequency was highest in men with lowest BMI, lowest ITS and lowest EL. Young adult BMI below the mean of 21.8 kg/m(2)was inversely associated with subsequent dementia, whereas there was no association with higher levels of BMI. Adjustment for young adult ITS and EL attenuated the risk estimates slightly, and interaction analyses showed that the shape of the association between BMI and dementia was unaffected by the levels of ITS and EL. Regardless of levels of ITS and EL, young adult BMI below the mean is inversely associated with subsequent dementia, whereas there is no association with higher levels of BMI.

AB - The risk of dementia seems to be established already early in life, which leads to the question if overweight early in life is an important risk factor for dementia as it appears to be later in life. We examined the association between body mass index (BMI) at entry to adult life and subsequent risk of dementia in men and assessed whether the relationship differed by levels of intelligence and education. The study population consisted of 377,598 Danish men born 1939-1959 with measures of height, weight, intelligence test score (ITS), and educational level (EL) at conscript board examinations around the age of 19 years. Dementia outcomes were obtained from National Patient and Prescription Registries between 1969 and 2016. The association between BMI and dementia was analysed using Cox proportional hazard regression including interactions between BMI and ITS and EL, respectively. During the follow-up through age 77 years, 6144 (1.6%) developed dementia. The frequency was highest in men with lowest BMI, lowest ITS and lowest EL. Young adult BMI below the mean of 21.8 kg/m(2)was inversely associated with subsequent dementia, whereas there was no association with higher levels of BMI. Adjustment for young adult ITS and EL attenuated the risk estimates slightly, and interaction analyses showed that the shape of the association between BMI and dementia was unaffected by the levels of ITS and EL. Regardless of levels of ITS and EL, young adult BMI below the mean is inversely associated with subsequent dementia, whereas there is no association with higher levels of BMI.

KW - Body mass index

KW - Dementia

KW - Intelligence

KW - Cohort study

KW - COGNITIVE IMPAIRMENT

KW - ALZHEIMERS-DISEASE

KW - LIFE

KW - SURVIVAL

KW - ABILITY

KW - WEIGHT

KW - COHORT

U2 - 10.1007/s10654-020-00665-w

DO - 10.1007/s10654-020-00665-w

M3 - Journal article

C2 - 32728913

VL - 35

SP - 843

EP - 850

JO - European Journal of Epidemiology

JF - European Journal of Epidemiology

SN - 0393-2990

ER -