Impaired glucose tolerance and insulin resistance in survivors of childhood acute lymphoblastic leukemia: prevalence and risk factors

Abnormal Glucose Metabolism and Body Composition Changes in Childhood Acute Lymphoblastic Leukemia Survivors During Their Adolescence

Childhood acute lymphoblastic leukemia survivors (ALL-S) face an increased risk of abnormal glucose metabolism (AGM). This study aimed to assess glucose metabolism in 141 ALL-S. All underwent an oral glucose tolerance test (OGTT) and were classified into AGM and normal glucose tolerance (NGT) groups. Insulin sensitivity and secretion indices were calculated from plasma glucose and serum insulin derived from the OGTT. Fat mass index (FMI) was derived from body composition analysis. Sixty-seven of 141 (48%) ALL-S had AGM. AGM was demonstrated in 33 of 98 nonobese ALL-S. ALL-S with AGM had a greater waist circumference percentile and FMI SD score than those with NGT. In addition, ALL-S with AGM had lower insulin sensitivity (greater homeostasis model assessment of insulin resistance: 2.3 [1.4, 3.3] vs. 1.0 [0.5, 1.4], P <0.001 and lower whole-body insulin sensitivity index: 3.5 [2.3, 4.1] vs. 7.9 [5.3, 10.9], P <0.001) and lower insulin secretion relative to insulin sensitivity (disposition index: 5.8 [4.2, 10.2] vs. 10.0 [6.1, 14.6], P <0.001) than those with NGT. Therefore, ALL-S could develop AGM regardless of their body mass index status. AGM in ALL-S stemmed from both insulin resistance and impaired insulin secretion.

Abnormal HDL lipid and protein composition following pediatric cancer treatment: an associative study

BACKGROUND

Long-term childhood cancer survivors (CCS) are at high risk of having dyslipidemia including low high density lipoprotein cholesterol (HDL-C). However, little is known about the prevalence of low HDL-C and the impact of therapy exposure on HDL composition early after treatment is terminated.

METHODS

This associative study included 50 children and adolescents who had completed their cancer treatments (< 4 years). Clinical characteristics (demographic, diagnosis, treatment, anthropometric parameters), fasting plasma lipids, apoliporoteins (Apo) A-I and composition of HDL fractions (HDL2 and HDL3) were assessed. Data were stratified according to the presence of dyslipidemia and median doses of therapeutic agents and compared using Fisher exact or Mann-Whitney tests. Univariate binary logistic regression analyses were carried out to evaluate the associations between the clinical and biochemical characteristics and having low HDL-C. Composition of HDL2 and HDL3 particles was assessed in a sub-group of 15 patients and compared to 15 age- and sex-matched healthy controls using Wilcoxon paired test.

RESULTS

Of the 50 pediatric cancer patients included in this study (mean age: 11.30 ± 0.72 y; mean time since end of treatment: 1.47 ± 0.12 y; male: 38%), 8 had low HDL-C (16%), all of which were adolescent at diagnosis. Higher doses of doxorubicin were associated with lower HDL-C and Apo A-I levels. In hypertriglyceridemic patients and compared to normolipidemics, triglycerides (TG) content was greater in HDL2 and HDL3 fractions whereas esterified cholesterol (EC) content was lower in HDL2. Enrich TG content of HDL3 and lower EC of HDL2 was found in patients exposed to ≥ 90 mg/m² doxorubicin. Factors positively associated with the risk of having low HDL-C were age, being overweight or obese and exposure to doxorubicin ≥ 90 mg/m². Compared to healthy controls, a sub-group of 15 patients showed higher TG and free cholesterol (FC) content of HDL2 and HDL3 and lower EC content in HDL3.

CONCLUSIONS

Overall, we found abnormalities in HDL-C and Apo A-I levels and in HDL composition early after pediatric cancer treatment that are influenced by age, overweight or obesity status and exposure to doxorubicin.

Cardiometabolic Health After Pediatric Cancer Treatment: Adolescents Are More Affected than Children

This cross-sectional study aimed at comparing the cardiometabolic (CM) health of children and adolescents and identifying factors associated with CM complications shortly after cancer treatment. Cancer-related characteristics, blood pressure (BP), anthropometry, and biochemical parameters were collected in 80 patients (56.3% female, mean age: 11.8 years; range: 4.5 - 21.0) a mean of 1.4 years following therapy completion. Compared to children, adolescents had higher mean z-score of insulin (-0.47 vs. 0.20; P = 0.01), HOMA-IR (-0.40 vs. 0.25; P = 0.02), waist-to-height ratio (0.36 vs. 0.84; P = 0.01), subscapular skinfold thickness (-0.19 vs. 0.47; P = 0.02), total body fat (-1.43 vs. 0.26; P < 0.01), and lower mean z-score of HDL-C (0.07 vs. -0.53; P < 0.01). Adolescents were more likely to have high BP (42% vs. 15%; P < 0.01), dyslipidemia (64% vs. 15%; P < 0.001), and cumulating ≥ 2 CM complications (42% vs. 2%; P < 0.001) than children. Adiposity indices (z-scores) were associated with high BP [odds ratio (OR) ranging from 2.11 to 4.09] and dyslipidemia (OR ranging from 2.06 to 4.34). These results suggest that adolescents have a worse CM profile than children shortly after therapy and that adiposity parameters are associated with CM complications, highliting the importance to develop intervention strategies targeting this population.

PAX proteins and their role in pancreas

Gene regulatory factors that govern the expression of heritable information come in an array of flavors, chiefly with transcription factors, the proteins which bind to regions of specific genes and modulate gene transcription, subsequently altering cellular function. PAX transcription factors are sequence-specific DNA-binding proteins exerting its regulatory activity in many tissues. Notably, three members of the PAX family namely PAX2, PAX4 and PAX6 have emerged as crucial players at multiple steps of pancreatic development and differentiation and also play a pivotal role in the regulation of pancreatic islet hormones synthesis and secretion. Providing a comprehensive outline of these transcription factors and their primordial and divergent roles in the pancreas is far-reaching in contemporary diabetes research. Accordingly, this review furnishes an outline of the role of pancreatic specific PAX regulators in the development of the pancreas and its associated disorders.

Clinical ascertainment of health outcomes in Asian survivors of childhood cancer: a systematic review

PURPOSE

Survivorship in children with cancer comes at a cost of developing chronic treatment-related complications. Yet, it is still an under-researched area in Asia, which shares the largest proportion of the global childhood cancer burden given its vast population. This systematic review summarizes existing literature on clinically ascertained health outcomes in Asian survivors of childhood cancer.

METHODS

A search was conducted on Ovid Medline and EMBASE for studies that focused on survivors of childhood cancer from countries in East and Southeast Asia; adopted post-treatment clinical ascertainment of organ-specific toxicities or/and secondary malignancy. Studies were excluded if health outcomes were assessed during the acute treatment.

RESULTS

Fifty-nine studies, enrolling a total of 13,442 subjects, were conducted on survivors of leukemia (34%), CNS tumor (14%), and cohorts of survivors with heterogeneous cancer diagnoses (52%). The studies used different medical evaluation methods to assess cardiovascular (15%), metabolic and infertility (32%), and neurological/neurocognitive (20%) outcomes in survivors. The collective findings suggest potential differences in the prevalence of certain late effects (e.g., secondary malignancy and obesity) among Asian and non-Asian populations, which may reflect differences in treatment regimens, practice, genetic variations, or/and socioeconomic disparity.

CONCLUSIONS

We recommend developing collaborative initiatives to build a regional repository of systematically assessed health outcomes and biospecimens to investigate treatment, social-environmental and genetic predictors, and interventions for late effects in this population.

IMPLICATIONS FOR CANCER SURVIVORS

The existing types of chronic health problems identified in this review suggest the need for active screening, better access to survivorship care, and promotion of protective health behavior in Asia.

The influence of genetic variation on late toxicities in childhood cancer survivors: A review

INTRODUCTION

The variability in late toxicities among childhood cancer survivors (CCS) is only partially explained by treatment and baseline patient characteristics. Inter-individual variability in the association between treatment exposure and risk of late toxicity suggests that genetic variation possibly modifies this association. We reviewed the available literature on genetic susceptibility of late toxicity after childhood cancer treatment related to components of metabolic syndrome, bone mineral density, gonadal impairment and hearing impairment.

METHODS

A systematic literature search was performed, using Embase, Cochrane Library, Google Scholar, MEDLINE, and Web of Science databases. Eligible publications included all English language reports of candidate gene studies and genome wide association studies (GWAS) that aimed to identify genetic risk factors associated with the four late toxicities, defined as toxicity present after end of treatment.

RESULTS

Twenty-seven articles were identified, including 26 candidate gene studies: metabolic syndrome (n = 6); BMD (n = 6); gonadal impairment (n = 2); hearing impairment (n = 12) and one GWAS (metabolic syndrome). Eighty percent of the genetic studies on late toxicity after childhood cancer had relatively small sample sizes (n < 200), leading to insufficient power, and lacked adjustment for multiple comparisons. Only four (4/26 = 15%) candidate gene studies had their findings validated in independent replication cohorts as part of their own report.

CONCLUSION

Genetic susceptibility associations are not consistent or not replicated and therefore, currently no evidence-based recommendations can be made for hearing impairment, gonadal impairment, bone mineral density impairment and metabolic syndrome in CCS. To advance knowledge related to genetic variation influencing late toxicities among CCS, future studies need adequate power, independent cohorts for replication, harmonization of disease outcomes and sample collections, and (international) collaboration.

The PETALE study: Late adverse effects and biomarkers in childhood acute lymphoblastic leukemia survivors

BACKGROUND

Childhood cancer survivorship issues represent an established public health challenge. Most late adverse effects (LAEs) have been demonstrated to be time and treatment dependent. The PETALE study is a multidisciplinary research project aiming to comprehensively characterize LAEs and identify associated predictive biomarkers in childhood acute lymphoblastic leukemia (cALL) survivors.

METHODS

cALL survivors treated at Sainte-Justine University Health Center with Dana-Farber Cancer Institution-ALL protocols 87-01 through 2005-01 were eligible. During Phase I of the study, the participants underwent comprehensive clinical, biologic, and psychosocial investigation targeting metabolic syndrome, cardiotoxicity, bone morbidity, neurocognitive problems, and quality of life issues. Whole-exome sequencing was performed for all participants. Subjects identified with an extreme phenotype during Phase I were recalled for additional testing (Phase II).

RESULTS

Phase I included 246 survivors (recall rate 71.9%). Of those, 85 participants completed Phase II (recall rate 88.5%). Survivors agreeing to participate in Phase I (n = 251) were similar to those who refused (n = 31) in terms of relapse risk profile, radiotherapy exposure, and age at the time of study. Participants, however, tended to be slightly older at diagnosis (6.1 vs. 4.7 years old, P = 0.08), with a higher proportion of female agreeing to participate compared with males (93.2 vs. 86.5%, P = 0.07).

CONCLUSION

The PETALE study will contribute to comprehensively characterize clinical, psychosocial, biologic, and genomic features of cALL survivors using an integrated approach. Expected outcomes include LAE early detection biomarkers, long-term follow-up guidelines, and recommendations for physicians and health professionals.

Targeting pancreatic expressed PAX genes for the treatment of diabetes mellitus and pancreatic neuroendocrine tumors

INTRODUCTION

Four members of the PAX family, PAX2, PAX4, PAX6 and PAX8 are known to be expressed in the pancreas. Accumulated evidences indicate that several pancreatic expressed PAX genes play a significant role in pancreatic development/functionality and alterations in these genes are involved in the pathogenesis of pancreatic diseases. Areas covered: In this review, we summarize the ongoing research related to pancreatic PAX genes in diabetes mellitus and pancreatic neuroendocrine tumors. We dissect the current knowledge at different levels; from mechanistic studies in cell lines performed to understand the molecular processes controlled by pancreatic PAX genes, to in vivo studies using rodent models that over-express or lack specific PAX genes. Finally, we describe human studies associating variants on pancreatic-expressed PAX genes with pancreatic diseases. Expert opinion: Based on the current literature, we propose that future interventions to treat pancreatic neuroendocrine tumors and diabetes mellitus could be developed via the modulation of PAX4 and/or PAX6 regulated pathways.

Metabolic syndrome in long-term survivors of childhood acute leukemia treated without hematopoietic stem cell transplantation: an L.E.A. study

Cardiovascular conditions are serious long-term complications of childhood acute leukemia. However, few studies have investigated the risk of metabolic syndrome, a known predictor of cardiovascular disease, in patients treated without hematopoietic stem cell transplantation. We describe the overall and age-specific prevalence, and the risk factors for metabolic syndrome and its components in the L.E.A. (Leucémie de l'Enfant et de l'Adolescent) French cohort of childhood acute leukemia survivors treated without hematopoietic stem cell transplantation. The study included 650 adult patients (mean age at evaluation: 24.2 years; mean follow-up after leukemia diagnosis: 16.0 years). The prevalence of metabolic syndrome was 6.9% (95% CI 5.1-9.2). The age-specific cumulative prevalence at 20, 25, 30 and 35 years of age was 1.3%, 6.1%, 10.8% and 22.4%, respectively. The prevalence of decreased high-density lipoprotein cholesterol, increased triglycerides, increased fasting glucose, increased blood pressure and increased abdominal circumference was 26.8%, 11.7%, 5.8%, 36.7% and 16.7%, respectively. Risk factors significantly associated with metabolic syndrome in the multivariate analysis were male sex (OR 2.64; 95% CI 1.32-5.29), age at last evaluation (OR 1.10; 95% CI 1.04-1.17) and body mass index at diagnosis (OR 1.15; 95% CI 1.01-1.32). The cumulative steroid dose was not a significant risk factor. Irradiated and non-irradiated patients exhibited different patterns of metabolic abnormalities, with more frequent abdominal obesity in irradiated patients and more frequent hypertension in non-irradiated patients. Survivors of childhood acute leukemia are at risk of metabolic syndrome, even when treated without hematopoietic stem cell transplantation or central nervous system irradiation. A preventive approach with regular screening for cardiovascular risk factors is recommended. clinicaltrials.gov identifier:01756599.

PAX4 R192H and P321H polymorphisms in type 2 diabetes and their functional defects

We have previously identified PAX4 mutations causing MODY9 and a recent genome-wide association study reported a susceptibility locus of type 2 diabetes (T2D) near PAX4. In this study, we aim to investigate the association between PAX4 polymorphisms and T2D in Thai patients and examine functions of PAX4 variant proteins. PAX4 rs2233580 (R192H) and rs712701 (P321H) were genotyped in 746 patients with T2D and 562 healthy normal control subjects by PCR and restriction-fragment length polymorphism method. PAX4 variant proteins were investigated for repressor function on human insulin and glucagon promoters and for cell viability and apoptosis upon high glucose exposure. Genotype and allele frequencies of PAX4 rs2233580 were more frequent in patients with T2D than in control subjects (P=0.001 and 0.0006, respectively) with odds ratio of 1.66 (P=0.001; 95% confidence interval, 1.22-2.27). PAX4 rs712701 was not associated with T2D but it was in linkage disequilibrium with rs2233580. The 192H/321H (A/A) haplotype was more frequent in T2D patients than in controls (9.5% vs 6.6%; P=0.009). PAX4 R192H, but not PAX4 P321H, impaired repression activities on insulin and glucagon promoters and decreased transcript levels of genes required to maintain β-cell function, proliferation and survival. Viability of β-cell was reduced under glucotoxic stress condition for the cells overexpressing either PAX4 R192H or PAX4 P321H or both. Thus these PAX4 polymorphisms may increase T2D risk by defective transcription regulation of target genes and/or decreased β-cell survival in high glucose condition.

Is there an increased risk of metabolic syndrome among childhood acute lymphoblastic leukemia survivors? A developing country experience

Data on metabolic syndrome (MS) in survivors of childhood acute lymphoblastic leukemia (ALL) from developing countries are lacking. The purpose of this single-center, uncontrolled, observational study was to assess the frequency of MS in our survivors. The survivors of ALL ≤15 years at diagnosis, who had completed therapy ≥2 years earlier, were enrolled. Anthropometric measurements (weight, height, waist circumference), biochemistry (glucose, insulin, triglycerides, high-density lipoprotein [HDL], thyroid function tests, C-reactive protein [CRP], magnesium), measurement of blood pressure, and Tanner staging were performed. MS was defined by International Diabetes Federation (IDF) and the National Cholesterol Education Program Third Adult Treatment Panel guidelines (NCEP ATP III) criteria, modified by Cook et al. (Arch Pediatr Adolesc Med. 2003;157:821-827) and Ford et al. (Diabetes Care. 2005;28:878-881). The median age of 76 survivors was 11.9 years (interquartile range [IQR]: 9.6-13.5). Twenty-four (32%) survivors were obese or overweight. The prevalence of insulin resistance (17%), hypertension (7%), hypertriglyceridemia (20%), and low HDL (37%) was comparable to the prevalence in children/adolescents in historical population-based studies from India. The prevalence of MS ranged from 1.3% to 5.2%, as per different defining criteria. Cranial radiotherapy, age at diagnosis, sex, or socioeconomic status were not risk factors for MS. The prevalence of MS in survivors of childhood ALL, at a median duration of 3 years from completion of chemotherapy, was comparable to the reference population. The prevalence of being obese or overweight was, however, greater than historical controls.

Medication-induced diabetes during induction treatment for ALL, an early marker for future metabolic risk?

Medication-induced diabetes (MID) is seen in children treated for acute lymphoblastic leukemia (ALL) mostly during induction, due to the use of l-asparaginase and glucocorticoids. Our objective was to assess whether MID during induction, is a risk factor for future impaired glucose tolerance (IGT), diabetes, or metabolic syndrome. Ninety survivors of pediatric ALL, ages 10 yr and older were recruited, 30 with history of MID and 60 controls. Waist/height ratio >0.5 was considered as an increased risk for central adiposity and insulin resistance. Lipid profile and an oral glucose tolerance test (OGTT) were performed. Study patients were older than controls (17.2 vs. 14.9, p < 0.05). The groups had similar sex distribution, body mass index (BMI) z-score, and Tanner staging. A waist/height ratio of >0.5 was seen in 60 and 31.7% of the study and control groups, respectively (p = 0.01). Increased frequency of IGT in the study group compared with the control group was seen (13.3 and 1%, respectively) (p = 0.07). We observed a trend toward higher proportion of patients with multiple features of metabolic syndrome in the study compared with control group (16.7 vs. 5%, p = 0.09). In conclusion, MID during induction may be an early marker for metabolic disturbances later in life. The higher rates of increased waist/height ratio, and subjects with multiple metabolic syndrome features, may predict a metabolic risk in children with history of MID. Rates of IGT were four fold higher in the study group although not statistically significant. MID may be a 'red flag' indicating the need for ongoing metabolic screening and lifestyle modifications to prevent future metabolic disease.

Metabolic syndrome and cardiovascular risk among long-term survivors of acute lymphoblastic leukaemia - From the St. Jude Lifetime Cohort

Adult survivors of childhood acute lymphoblastic leukaemia (ALL) have a four-fold excess risk of mortality from cardiovascular disease. This cardiovascular risk has not been fully characterized. ALL survivors [n = 784, median age 31·7 years (18·9-59·1)] in the St. Jude Lifetime Cohort Study underwent evaluation for cardiovascular risk and metabolic syndrome (MetS) according to National Cholesterol Education Program - Adult Treatment Panel III criteria. Comparisons were made to 777 age-, sex-, and race-matched controls from the National Health and Nutrition Examination Survey (NHANES). MetS was identified in 259 survivors (33·6%) and associated with older age in 5-year increments (relative risk [RR] 1·13, 95% confidence interval [CI] 1·06-1·19) and prior cranial radiotherapy (CRT) (with craniospinal radiation: RR 1·88, 95%CI 1·32-2·67; without: RR 1·67, 95%CI 1·26-2·23). Measures of obesity were highly prevalent among female survivors and CRT recipients. Compared to NHANES controls, ALL survivors had a higher risk of MetS (RR 1·43, 95%CI 1·22-1·69), hypertension (RR 2·43, 95%CI 2·06-2·86), low high-density lipoprotein (RR 1·40, 95%CI 1·23-1·59), obesity (RR 1·47, 95%CI 1·29-1·68) and insulin resistance (1·64, 95%CI 1·44-1·86). This large study of clinically evaluated ALL survivors identified a high prevalence of MetS, obesity and cardiovascular risk, particularly in CRT recipients, underscoring the need for screening and aggressive reduction of modifiable risks.

Prevalence of cardiovascular risk factors in long-term survivors of childhood cancer: 16 years follow up from a prospective registry

BACKGROUND

Childhood cancer survivors (CCSs) have an increased risk of overweight and dyslipidaemia, but the distribution and the potential relationships between anticancer therapies and cardiovascular risk factors have been heterogeneously and not prospectively described.

METHODS

All consecutive CCSs with primary cancer diagnosed between 1973-2007 and subsequently referred to our outpatient clinic were enrolled. Hypercholesterolaemia (total cholesterol >200 and/or low density lipoprotein (LDL)>160 mg/dl) was the primary end point, hypertriglyceridaemia (triglycerides >200 mg/dl) and body mass index >30 kg/m(2) the secondary end points. Cox multivariate adjustments were performed to account for differences in cancer and treatments.

RESULTS

A total of 340 patients were included (197 male, 143 female; mean age at last follow-up 24.1 ± 3.2). The most common diagnosis were haematological malignancies (n = 227) and brain tumours (n = 51). After a median follow-up of 16.1 years, hypercholesterolaemia was diagnosed in 67 CCSs (20%), hypertriglyceridaemia in 20 CCSs (6%) and obesity in 28 CCSs (8%). Total body irradiation and growth hormone deficiency increased the risk of both hypercholesterolaemia (hazard ratio (HR) = 2.7; confidence interval (CI) 1.2-4.4 and HR = 2.3; CI 1.1-4.9; all p < 0.05) and hypertriglyceridaemia (HR = 6.5; CI 1.4-31 and HR = 7.2; CI 1.1-43; all p < 0.05). The risk of hypercholesterolaemia was also higher in CCSs who underwent autologous haematopoietic stem cell transplantation (HR = 3.2; CI 1.7-5.9; p < 0.001) or platinum-based chemotherapy (HR = 2.7; CI 1.5-4.9; p < 0.001), whereas a previous diagnosis of brain tumour (HR = 10; CI 1.2-45; p < 0.05) and anthracyclines exposure (HR = 1.3; CI 1.2-26; p < 0.05) significantly predicted obesity.

CONCLUSION

CCSs show a high and variable risk for developing dyslipidaemia and obesity, depending on cancer diagnosis and treatments. Therefore, they need accurate and tailored control of their cardiovascular risk profile.

Pharmacogenetic considerations for acute lymphoblastic leukemia therapies

INTRODUCTION

Advances in our understanding of the pathobiology of childhood acute lymphoblastic leukemia (ALL) have led to risk-targeted treatment regimens and remarkable improvement in survival rates. Still, up to 20% of patients experience treatment failure due to drug resistance. Treatment-related toxicities are often life-threatening and are the primary cause of treatment interruption, while ALL survivors may develop complications due to exposure to chemotherapy and/or irradiation during a vulnerable period of development. Different factors may contribute to variable treatment outcomes including patient genetics that has been shown to play important role.

AREAS COVERED

This review summarizes candidate gene and genome-wide association studies that identified common polymorphisms underlying variability in treatment responses including a few studies addressing late effects of the treatment. Genetic variants influencing antileukemic drug effects or leukemic cell biology have been identified, including for example variants in folate-dependent enzymes, influx and efflux transporters, metabolizing enzymes, drug receptor or apoptotic proteins.

EXPERT OPINION

Many pharmacogenetic studies have been conducted in ALL and a variety of potential markers have been identified. Yet more comprehensive insight into genome variations influencing drug responses is needed. Whole exome/genome sequencing, careful study design, mechanistic explanation of association found and collaborative studies will ultimately lead to personalized treatment and improved therapeutic and health outcomes.