Assessment of Bone Health and Endocrine Function in 90 Survivors of Childhood Lymphoblastic Leukemia

Program: Abstracts - Orals, Featured Poster Presentations, and Posters
Session: MON 596-630-Pediatric Endocrinology
Clinical
Monday, June 17, 2013: 1:45 PM-3:45 PM
Expo Halls ABC (Moscone Center)

Poster Board MON-609
Pia K Hauffa*1, Corinna Grasemann2, Jens J Bauer3, Sarah C Goretzki4, Laura Marschke3, Harald Lahner5, Angelika Eggert4, Berthold P Hauffa6 and Michael M Schündeln7
1Universitätsklinikum Essen, Kinderklinik, 2Universität Duisburg - Essen, Kinderklinik II, Essen, Germany, 3Kinderklinik II, Universitätsklinikum Essen, 4Kinderklinik III, Universitätsklinikum Essen, 5Universitatsklinik Essen, Essen, Germany, 6Univer, Essen, Germany, 7Kinderklinik III, Universitätsklinikum Essen, Essen, Germany
Introduction: Lymphoblastic leukemia is the predominant form of childhood malignancies with survival rates of > 80%. Late effects of cancer and treatment can affect endocrine function and may account for acute and chronic impairment of bone health.

Aim and Design: To assess bone health in pediatric patients after therapy for lymphoblastic leukemia we initiated a clinical trial investigating clinical and biochemical parameters of growth, puberty, bone turnover, and vitamin D metabolism, as well as bone densitometry using DXA scans in a subgroup of patients. Additionally a questionnaire was developed assessing life style parameters including calcium and vitamin D intake and levels of physical activity. Patients (n=90) were treated for leukemia according to applicable ALL-BFM protocol (1994 – 2011) and recruited at follow-up visits at the Children’s Hospital Essen.

Results: 39 of the 90 patients were female. Mean (range) chronological age (CA)was 11.47 (3.8 – 20.9) y, age at diagnosis was 6.9 (0.8 – 16.9) y, height SDS -0.04 (-3.69 – 2.72), BMI SDS 0.48 (-4.12 – 2.74), SDS for Tanner stage 0.22 (-3.2 – 3.5). Mean serum 25-OH vitamin D levels were 17.34 (1 – 62.6) ng/ml, 1.25 (OH)2vitamin D levels were 60.2 (13 – 158) ng/l, BAP was 119.9 (18.3 – 283)U/l, PTH 46.7 (9.6 – 159.8) pg/ml, N-telopeptide in urine 908.8 (21 – 3000) mmol/mg creatinine and calcium/creatinine ratio in urine was 0.12 (0.01 – 0.4) mg/mg. Mean calcium intake/week was 5.64 g (1.2 – 10.5), vitamin D intake: 15.4 mcg (0.22 – 46.6). Average screentime was 1.9 (0 – 5) hours /day, average daily activity: 5.12 hours/day. Mean age corrected z-score in DXA scans was -0.55 (-3.3 – 2.1, n =30).

11% of the patients experienced fractures after chemotherapy, 3 patients reported frequent fractures. Vitamin D deficiency (25 OH-vitamin D < 20 ng/ml) was observed in 68% and secondary hyperparathyroidism in 17%.  15% reported bone pain after physical activity. Male and female patients did not differ significantly with respect to biochemical or clinical findings. There was a trend to lower height SDS in boys in this cohort. Accordingly mean bone age (BA) was delayed in boys (Delta BA/CA: -1.7 (-5.1 – 0.33)y. Osteopenia  (z-score <-2) was detected in 15% of the patients screened. No correlation between z-scores and N-telopeptide levels in urine or total dosage of prednisone, dexamethasone or methotrexate was observed.

Conclusion: Bone health is impaired in some patients after treatment for childhood leukemia. Clinically this is reflected in bone pain and/or fractures. Prediction or identification of children at risk is difficult and requires assessment of additional clinical, biochemical and radiological measures. As previously reported, vitamin D and calcium deficiencies are frequent findings in this group and adequate monitoring and supplementation is recommended.  

Abbreviations: y – years, BAP – bone specific alkaline phosphatase, DXA - Dual-energy X-ray

Nothing to Disclose: PKH, CG, JJB, SCG, LM, HL, AE, BPH, MMS

*Please take note of The Endocrine Society's News Embargo Policy at http://www.endo-society.org/endo2013/media.cfm

Sources of Research Support: IFORES stipend of the Faculty of Medicine, University Duisburg-Essen awarded to CG