Leptin Assessment in Acute Lymphocytic Leukemia Survivors: Role of Cranial Radiotherapy?

Abstract

Leptin has been hypothesized to play a role in the development of obesity in leukemia survivors, particularly those who have received cranial radiotherapy. This cross-sectional study evaluated the relationship between leptin levels and body mass index (BMI) in a sample of 26 acute lymphocytic leukemia survivors of both sexes, treated with and without cranial irradiation, aged 7.6 to 17 years, at a mean 3.4+/-2.0 years off treatment. There were significantly more males among the irradiated group (P<0.001), even though no differences were encountered in pubertal stage (P=1.000), BMI standard deviation score (mean+/-SD) (0.68+/-1.00 vs. 1.19+/-0.78; P=0.164), or leptin concentrations (17.01+/-17.04 vs. 23.3+/-13.4; P=0.309). Nonetheless, there was a positive correlation between the natural logarithm of leptin and BMI standard deviation score [t(22)=2.348, P=0.028], however, no differences were recorded among irradiated and nonirradiated patients [F(2,22)=0.384, P=0.685]. When this relationship was compared between sexes, a significant difference was encountered [F(2,22)=4.907, P=0.017], with males having the strongest association (R(2)males=65.5%, R(2)females=34.7%). Leptin is a reliable adiposity index as it strongly correlates with BMI. Overall, the current data suggest that cranial irradiation did not play a role upon this relationship; however, sex differences influenced positively this correlation.

Cranial radiotherapy predisposes to abdominal adiposity in survivors of childhood acute lymphocytic leukemia

“…The Childhood Cancer Survivor Study showed that the influence of CRT on the increase in BMI in ALL survivors was more evident in females exposed to CRT. To date, few patients in the present study were currently considered obese by means of BMI analysis (2 males, 8.3% of the ALL male subjects versus 13.8% from the Childhood Cancer Survivor Study at the age of 18-24 years) [3], which is in accord with other studies that have not found obesity in survivors of ALL by employing measures of BMI, despite the rebound of adiposity [8,9,37]. …”

“…These alterations could lead to body fatness and metabolic derangements, both of which are factors that are suggested to contribute to features of the metabolic syndrome in this group of patients [2,4-6,11-14]. However, other factors that interact with the disease and/or therapy, such as individual host and genetic characteristics, may moderate and influence adiposity and metabolic derangements in this group of patients [3,7,8]. …”

“…Alterations in body fat and metabolic panel are clearly multifactorial, being regulated by gender, host characteristics, therapeutic agents (chemotherapy and exposure to CRT) and hormonal deficiencies. Although it was not within the aim of this study, factors other than CRT could have influenced body fatness and metabolic profile in this population, such as the young age, shorter post treatment interval, overprotection due to illness, intense parental care giving, and medical support [5,6,8]. …”

“…Various mechanisms of weight gain have been reported in this group of patients, including premature adiposity rebound, growth hormone deficiency, leptin insensitivity and other factors related to lifestyle and genetics [2,4,7,8]. Nonetheless, some studies have not characterized obesity by means of body mass index (BMI) in ALL survivors, despite exposure to cranial radiotherapy (CRT) [8,9], even though an increase in BMI has often been described in this group of patients [2-4,6].…”

“…Nonetheless, some studies have not characterized obesity by means of body mass index (BMI) in ALL survivors, despite exposure to cranial radiotherapy (CRT) [8,9], even though an increase in BMI has often been described in this group of patients [2-4,6]. …”