Energy expenditure, energy intake and prevalence of obesity after therapy for acute lymphoblastic leukemia during childhood.

OBJECTIVES

To investigate the prevalence and potential risk factors of obesity after therapy for childhood acute lymphoblastic leukemia (ALL).

STUDY DESIGN

39 ALL patients (age 10.7-20.5 years) who were in first remission for 3.4-14.6 years after standardized treatment with chemotherapy plus cranial irradiation (n = 25) or with chemotherapy alone (n = 14) were examined. After fasting overnight, the following parameters were investigated: body mass index (BMI) of patients and their parents; patients' BMI before ALL therapy; serum free thyroxin, growth hormone-dependent factors, estradiol, testosterone, cortisol, leptin and c-peptide; fat-free mass (bioelectrical impedance); resting metabolic rate (RMR, indirect calorimetry); caloric intake (24-hour recall); and physical activity (questionnaire). RMR data were applied to the fat-free mass and compared with 83 controls.

RESULTS

The prevalence of obesity (criterion: BMI > 2 SDS) was significantly (p < 0.05) higher after ALL therapy (38%; irradiated patients 48%, non-irradiated patients 21%) than before therapy (3%). Compared to non-irradiated patients, irradiated patients had significantly lower RMRs (-1.07 +/- 0.24 vs. -0.32 +/- 0.21 SDS; p < 0.05), reduced physical activity levels (1.41 +/- 0.03 vs. 1.52 +/- 0.03; p < 0.05), and lower concentrations of insulin-like growth factor-binding protein-3 (-0.65 +/- 0.17 vs. 0.25 +/- 0.33 SDS; p < 0.05) and of free thyroxin (1.17 +/- 0.06 vs. 1.38 +/- 0.08 ng/dl; p < 0.05). Caloric intake was adequate.

CONCLUSIONS

After ALL during childhood, patients face a higher risk of obesity. In the cranially irradiated patients, the likely causes are low physical activity, RMRs and hormonal insufficiency.