Weight gain, obesity prevalent among childhood brain tumor survivors
Childhood brain tumor survivors have a high prevalence of significant weight gain, overweight and obesity, and changes in BMI may indicate hypothalamic-pituitary dysfunction, according to a study published in Journal of Clinical Oncology.
The findings, observed among children without craniopharyngioma, highlight the need for more intense endocrine surveillance and interventions to control weight and curtail serious risk for adverse metabolic health effects, such as cardiovascular morbidity, according to researchers.
“Other literature had previously shown that there is a high prevalence of obesity among childhood brain tumor survivors. Due to the fact that many previously reported brain tumor cohorts included patients with craniopharyngioma, which may greatly influence the overall prevalence of weight gain, we were interested in the prevalence of overweight and obesity in a noncraniopharyngioma cohort,” Jiska van Schaik, MSc, PhD student in pediatric endocrinology and oncology, and pediatric endocrinologist Hanneke van Santen, MD, PhD, both of Princess Màxima Center for Pediatric Oncology and Wilhelmina Children's Hospital at the University Medical Center Utrecht in the Netherlands, said in a joint statement to Healio.
“In addition, attention has been focused on obesity, but numbers on the prevalence of overweight and significant weight gain in childhood brain tumor survivors had not been reported before,” they continued.
The analysis by van Schaik, van Santen and colleagues included 661 childhood brain tumor survivors (median age at diagnosis, 7.4 years; 53.8% male) from a previously reported nationwide retrospective cohort in the Netherlands who were diagnosed at age 18 years or younger with a brain tumor between 2002 and 2012, survived at least 2 years after diagnosis and had follow-up data on BMI at least 6 months after diagnosis.
Researchers excluded those who had craniopharyngioma and pituitary tumors.
They defined significant weight gain as an increase in BMI greater than or equal to +2 standard deviation score (SDS) from diagnosis to most recent follow-up.
Mean follow-up was 7.3 ± 3.1 years.
Results showed 33.1% of survivors developed significant weight gain, overweight or obesity. This included 70 (11.6%) survivors who developed significant weight gain during follow-up and 190 (28.7%) classified as overweight (20.3%) or obese (8.5%) at most recent follow-up, with a mean BMI SDS of 2.6 ± 1 after mean follow-up of 7.8 ± 3.3 years.
“We were surprised that the prevalence of weight gain and overweight is still so high in childhood brain tumor survivors after exclusion of craniopharyngioma and pituitary tumors,” van Schaik and van Santen told Healio.
Prevalence also appeared high in comparison with the general Dutch population. Among 578 childhood brain tumor survivors aged between 4 and 20 years at follow-up, 20.3% classified as overweight, compared with 10.5% of their same-aged counterparts in the general population. The difference appeared even greater among those in that age group who classified as obese (8.5% of survivors vs. 2.7% of general population).
“The obesity prevalence is almost four times increased in these children,” van Schaik and van Santen said.
Greater likelihood of overweight or obesity at follow-up appeared associated with higher vs. lower BMI SDS at diagnosis (OR = 2; 95% CI, 1.7-2.34), low-grade glioma vs. other brain tumors (OR = 1.68; 95% CI, 1.05-2.67), presence vs. absence of diabetes insipidus during follow-up (OR = 6.41; 95% CI, 1.35-30.41) and presence vs. absence of central precocious puberty during follow-up (OR = 3.12; 95% CI, 1.38-7.04).
“Thus, it seems to be that weight gain in childhood brain tumor survivors is more frequently related to hypothalamic-pituitary dysfunction than most professionals are currently aware of,” van Schaik and van Santen said.
The study’s limitations included the lack of a national protocol for surveillance of BMI and hypothalamic-pituitary in childhood brain tumor survivors and that BMI does not differentiate between the amount of fat mass, fat-free mass and muscle mass.
The researchers also admitted their definition of significant weight gain was fairly strict.
“By using our cutoff point for weight gain of BMI +2 SDS, our results may even have underestimated the prevalence of weight gain, and it is important for oncologists and endocrinologists to be aware of these metabolic changes during follow-up,” van Schaik and van Santen said.
“Future studies are needed to further reveal the cause of weight gain — be it hypothalamic-pituitary dysfunction, dietary, decreased physical activity or genetic/environmental — and should include BMI of parents and siblings, monitor physical activity and diet, and look into genetic factors,” they added.
For more information:
Hanneke van Santen, MD, PhD, and Jiska van Schaik, MSc, can be reached at Department of Pediatric Endocrinology, Wilhelmina Children’s Hospital/Princess Màxima Center, PO Box 85090, 3508 AB, Utrecht, the Netherlands; email van Santen at firstname.lastname@example.org; email van Schaik at email@example.com.