BACKGROUND
Overweight and obesity are common challenges among childhood cancer survivors. Overweight may be disguised, as survivors can have normal weight but high fat percentage (fat%) on dual-energy X-ray absorptiometry (DXA). We aimed to assess prevalence, identify determinants and biomarkers and assess which method captures overweight best, in a nationwide cohort.
METHODS
Prevalence of overweight and obesity, primarily defined by body mass index, was assessed in the DCCSS-LATER cohort of adult survivors treated 1963-2002, with the LifeLines cohort as reference. Associations between risk factors and overweight metrics were investigated using logistic regression. Additional overweight metrics included DXA-fat%, waist circumference (WC), waist/hip-ratio (WHR), waist/height-ratio (WHtR), and high-molecular-weight-(HMW)-adiponectin.
RESULTS
2,338 (mean age 35.5y, follow-up 28.3y) survivors participated. Overweight prevalence was 46.3% in men and 44.3% in women (obesity 11.2% and 15.9%, morbid obesity 2.4% and 5.4%), with highest rates among brain tumor survivors. Compared to controls, there was no overall increased overweight rate, but this was higher in women >50y, morbid obesity in men >50y. Overweight at cancer diagnosis (adjusted odds ratio (aOR) = 3.83, 95%CI = 2.19-6.69), cranial radiotherapy (aOR = 3.21, 95%CI = 1.99-5.18) and growth hormone deficiency (separate model, aOR = 1.61, 95%CI = 1.00-2.59) were associated with overweight. Using BMI, WC, WHR and WHtR, overweight prevalence was similar. Low HMW-adiponectin, present in only 4.5% of survivors, was an insensitive overweight marker. DXA-based classification identified overweight in an additional 30%, particularly after abdominal radiotherapy, total body irradiation, anthracyclines and platinum.
CONCLUSIONS
Overweight occurs in almost half of long-term survivors. There was no overall increased incidence of overweight compared to controls. We identified factors associated with overweight, as well as subgroups of survivors in whom DXA can more reliably assess overweight.