The U‐shaped association of body mass index with mortality: Influence of the traits height, intelligence, and education

• Published in: Obesity (Silver Spring, Md.) Vol. 24; no. 10; pp. 2240 - 2247
• Main Authors: Jørgensen, Terese Sara Høj, Osler, Merete, Ängquist, Lars Henrik, Zimmermann, Esther, Christensen, Gunhild Tidemann, Sørensen, Thorkild I.A.
• Format: Journal Article
• Language: English
• Published: United States Blackwell Publishing Ltd 01.10.2016
• Subjects: Adult; Aged; Body Height - physiology; Body Mass Index; Body Weight - physiology; Cohort Studies; Denmark - epidemiology; Educational Status; Humans; Intelligence; Intelligence tests; Male; Middle Aged; Mortality; Obesity; Overweight - mortality; Studies; Survival Rate; Thinness - mortality; Young Adult
• ISSN: 1930-7381; 1930-739X
• DOI: 10.1002/oby.21615

Objective The U‐shaped association between body mass index (BMI) and mortality may depend on other traits with permanent health effects. Whether the association between BMI and mortality depends on levels of health‐related traits known to be inversely associated with mortality throughout adult life such as height, intelligence, and education was investigated. Methods The study was based on a cohort of young men with data on weight, height, intelligence test score, and education from the Danish Conscription Database. In total, 346,500 men born 1939 to 1959 were followed until December 2013. The association between BMI and mortality was analyzed using Cox‐regression models including interactions between BMI and height, intelligence, and education, respectively. Results BMI and mortality showed the U‐shaped association from the start of the follow‐up period, and it persisted through the subsequent 56 years. As expected, the mortality was inversely associated with height, intelligence, and education, but the U shape of the association between BMI and mortality was unaffected by the levels of these traits except at higher BMI values, where the slopes were steeper for men with higher levels of height, intelligence, and education. Conclusions High and low BMI was associated with higher mortality throughout life regardless of the levels of height, intelligence, and education.