Genetic Polymorphisms of β-Cell Differentiation Confer Risk of Alterations of Glucose Metabolism in Survivors of Childhood Acute Lymphoblastic Leukemia.

Purpose: Long-term survivors of acute lymphoblastic leukemia (ALL) seem to be at risk of insulin resistance, impaired glucose tolerance and may develop typical signs of metabolic syndrome with disturbances in lipid metabolism. The aim of the present study was to study the prevalence of alterations in glucose metabolism and the predisposing factors of these disturbances in survivors of childhood ALL. Furthermore, we intended to identify the role of such genetic polymorphisms affecting β-cell function and glucose metabolism and possibly to develop them as markers for monitoring β-cell dysfunction following treatment for ALL in the future.

Patients and methods: In 131 ALL survivors after cessation of therapy, an oral glucose tolerance test was performed to determine β-cell function/insulin sensitivity. Six single-nucleotide polymorphisms of PAX4 and TCF7L2 genes were genotyped in order to evaluate the association between these polymorphisms and β-cell function/insulin sensitivity.

Results: Ten out of 131 (7.6%) survivors had impaired glucose tolerance (IGT) while 40 out of 131 (30.5%) had insulin resistance (IR) and demonstrated characteristics of metabolic syndrome (hyperinsulinemia, hypertriglyceridemia, low HDL-C). In the logistic regression analysis, the most important factor predicting IGT and IR was older current age (p= 0.010 and <0.001, respectively) while the PAX4 R192H mutation (rs2233580) was significant associated only to IGT after adjusted for age (p=0.043) (adjusted OR 5.28, 95%CI 1.06–26.40).

Conclusion: Our findings suggest that older age of childhood ALL survivors is the most important risk factor of IGT and IR, underlining the need to continue regular and long-term screening till adulthood. Moreover, after adjusted for age, the PAX4 R192H variant (rs2233580) seemed to be associated with IGT. If this association is confirmed, institution of lifestyle and therapeutic measures may be needed to reduce metabolic risk and diabetes.