Taller children

A study of more than 300,000 individuals in Denmark, presented at this year’s European Congress on Obesity in Glasgow; Scotland (28 April-1 May), reveals that heavier and taller children are at greater risk than their average-sized peers of developing renal cell carcinoma (RCC) as adults. RCC is the most common form of kidney cancer in adults. Although it often occurs in men between the ages of 50 and 70, cancer can diagnosed throughout adulthood. Medical experts don’t know the exact causes of RCC.
They know that overweight in adulthood is with an increased risk of RCC. They also know that cancers take many years to develop. They, therefore, had a theory that already being overweight in childhood would increase the risk of RCC later in life,” explains lead author Dr. Britt Wang Jensen. In their study, the researchers included 301,422 individuals (152,573 men) from the CSHRR, born from 1930 to1985.

Risk of developing RCC

The weights and heights measured at annual school health examinations at the ages 7-13 years; body mass index (BMI) was used to categorize the children as normal-weight or overweight; based on age- and sex-specific cut-offs suggested by the International Obesity Task Force. Cases of RCC by linkage to the Danish Cancer Registry. To analyze the data, the researchers used a statistical technique as the Cox proportional hazards regression. The procedure relates several factors or exposures considered simultaneously to measure the risk of an outcome; in this case, the risk of developing RCC.

Compared to children with a normal-weight at 7 and 13 years, children with overweight at both ages did not have increased risks of RCC; whereas children with normal-weight at 7 years and overweight at 13 years had a 67% greater risk of developing this cancer. Compared to children with an average height at 7 and 13 years, children who 0.5 z-score taller than average at age 7 years and remain taller than average until age 13 years have a 6% increased risk of RCC. Children who grew from average to above average height had an 8% increased risk of RCC.
The authors say: “They have found in other studies that childhood height is positive with several cancer forms. Therefore, they did expect to find that tall children have a higher risk of RCC than average-sized children.” They conclude: “Our findings that heavier and taller children have increased risks of RCC opens the door to new ways to explore the causes of kidney cancer.”