Early life body size, including birth weight and overweight, may predict a person’s risk of renal cell carcinoma (RCC) as adults, according to investigators.
“Our findings indicate that RCC may originate earlier in life than previously thought and suggest that new explorations into the mechanisms underlying these associations should be undertaken,” a team led by a team led by Jennifer Lyn Baker, PhD, of the Bispebjerg and Frederiksberg Hospital, The Capital Region, Copenhagen, reported in the European Journal of Epidemiology.
For their observational cohort study, Dr Baker and her colleagues obtained information on measured heights and weights of 301,418 children from the Copenhagen School Health Records Register born 1930 to 1985 and information on birth weight by parental report. The investigators identified RCC cases using the Danish Cancer Registry. RCC was diagnosed in 1010 individuals (680 boys, 330 girls) during 8.9 million person-years of follow-up. The median age at diagnosis was 62 years for both men and women.
Results showed that each 500-gram increase in birth weight was significantly associated with a 12% increased risk of RCC in adulthood. Children who were overweight at age 13 had a significant 40% increased risk of RCC compared with those who had a normal body mass index (BMI) at that age. In addition, compared with children who had a normal BMI at ages 7 and 13 years, those who were overweight only at age 13 years had a significant 67% increased risk of RCC. Individuals who were overweight at age 7 years only and at ages 7 and 13 years did not have an increased risk of RCC.
The investigators defined overweight according to cut points suggested by the International Obesity Task Force. For girls, overweight at ages 7 and 13 years was a BMI of 17.69 kg/m2 or higher and 22.49 kg/m2 or higher, respectively. For boys, overweight at ages 7 and 13 was a BMI of 17.88 kg/m2 or higher and 21.89 kg/m2 or higher, respectively.
Children who were persistently taller than average at ages 7 and 13 had a higher risk of RCC in adulthood than boys and girls with average height at ages 7 and 13 years.
“Our results show that a high BMI in childhood relates to the risk of RCC, and this extends the associations to younger ages than shown in previous studies,” the authors wrote. “Adjustment for birth weight had little influence on the results, thus suggesting that the observed associations were not due to an effect of children with a high BMI also having a high birth weight.”
Jensen BW, Meyle KD, Madsen K, et al. Early life body size in relation to risk of renal cell carcinoma in adulthood: a Danish observational study [published online January 28, 2020]. Eur J Epidemiol. doi: 10.1007/s10654-020-00605-8