Adiposity in Early Life and Risk of Lymphoid Malignancies in Middle Age: a UK-based Prospective Study
Higher body mass index (BMI) in middle age is associated with increased risk of lymphoid malignancies. Little is known about whether adiposity in childhood or early adulthood has an independent association with lymphoid malignancies in middle age.
METHODS:
In the Million Women Study, a large cohort of middle-aged UK women, participants were asked to report various health and lifestyle characteristics by questionnaire, including relative adiposity at age 10 years (thin, average or plump compared to peers) and clothes size at age 20 years (<12, 12-14, 16+). Prospectively collected data available from a subset of women who also participated in the National Survey of Health and Development were used to estimate BMI within self-reported categories. We followed women for death or cancer registration by linkage to the UK National Health Service Central Registers.
RESULTS:
Among 746,345 women (age 59 years on average at baseline) followed for 9 years on average, we identified 4506 lymphoid malignancies. After adjustment for year of birth, region, socioeconomic status, parental smoking at age 10 years, height, and smoking, the relative risk of lymphoid malignancy in middle-age was significantly associated with both self-reported body size at age 10, and clothes size at age 20. There were also significant trends in the relative risk of lymphoid malignancies with increasing estimated BMI at ages 10 and at age 20 (p=0.002 for trend per 5 kg/m2 at age 10, and p<0.001 for trend per 5 kg/m2at age 20). The relative risks were attenuated but remained significant after additional adjustment for current BMI (p=0.02 for age 10, and p<0.001 for age 20). We found no evidence that the associations varied across subtypes of lymphoid malignancies.
CONCLUSIONS:
In this cohort of middle-aged UK women, greater adiposity in childhood or early adulthood is associated with a higher risk of lymphoid malignancies.