Childhood body mass index is associated with the risk of adult hematologic malignancies in men-The best Gothenburg cohort.

Hematologic malignancies are common and the incidence is increasing. Adult obesity has been associated with hematologic malignancies (HM), but the importance of body mass index (BMI) in childhood and during puberty has not been evaluated. The aim of the present study was to evaluate the relative contribution of BMI and height in childhood and during puberty for the risk of adult HM. 37 669 men born in 1946 to 1961 who had weight and height measured at 8 (childhood) and 20 (young adult age) years of age available from the BMI Epidemiology Study were included in the study. Pubertal BMI change was calculated as BMI at 20 years of age minus BMI at 8 years of age. Information on HM was retrieved from Swedish registers (459 cases of HM). Hazard ratios (HR) and 95% confidence intervals (CI) were estimated by Cox regressions. Childhood BMI (HR 1.11 per SD increase [95% CI 1.02-1.23]), but not pubertal BMI change, was associated with hematologic malignancies in a linear manner. Childhood BMI was, independent of childhood height, associated with the diagnostic entities Non-Hodgkin lymphoma (HR 1.14 [95% CI 1.00-1.30]) and its largest subgroup diffuse large B-cell lymphoma (HR 1.31 [95% CI 1.03-1.67]). Childhood height was associated with multiple myeloma (HR 1.30 [95% CI 1.04-1.64]) independent of childhood BMI. We conclude that childhood but not puberty is the critical developmental period regarding future risk of HM and we suggest that elevated childhood BMI is a determinant of Non-Hodgkin lymphoma and diffuse large B-cell lymphoma.