Bone mineral density and its determinants in long-term childhood Hodgkin's lymphoma survivors - a pilot study

Abstract

Aim : The purpose of this study is to evaluate bone mineral density (BMD) and its determinants in long-term survivors of childhood Hodgkin`s lymphoma (HL), treated and followed up in a single center. Methods: We compared 18 long-term survivors between 18 and 34 years of age (mean age 26.2 ± 3.9 yrs), to 25 age- and sex-matched controls and assessed their anthropometric features and biochemical and hormonal parameters. The participants` BMD, BMD Z-scores and young-adult T-scores, bone mineral content (BMC), fat mass (FM), lean mass (LM) and appendicular lean mass (ALM) were measured by whole body Dual-energy X-ray absorptiometry (DEXA). Their physical activity (PA) was assessed through the means of questionnaires and semi-structured interviews. Results: An average of 12.3 ± 3.2 yrs after treatment completion, HL survivors had lower BMD Z-scores and BMD young-adult T-scores (-0.03 ± 1.07 vs 0.69 ± 1.19, р = 0.04 and -0.20 ± 0.92 vs 0.48 ± 1.27, р = 0.07, respectively). Hypergonadotropic hypogonadism was found in 54.5% of male survivors, and 3 out of 7 female survivors presented with thyroid dysfunction. No participant had SDS BMD lower than -2. The frequency rate of BMD Z-scores < -1 among survivors was 16.7% (3/18). All HL survivors with a BMD Z-score < -1 were males. They were treated with more intensive therapy (n=3) and 2 of them presented with treatment-induced hypogonadism. Compared to controls, survivors, especially women, exhibited lower physical sports activity frequency and duration (1.6 ± 2.1 vs 3.7 ± 3.4/week, p = 0.02 and 90 ± 127 vs 279 ± 419 min/week, p = 0.06). BMD positively correlated with LM, ALM and physical activity parameters. Lean mass, older age at diagnosis and the dose of the radiotherapy delivered during treatment were all independent predictors of BMD in HL survivors. Conclusion: Compared to controls, long-term childhood HL survivors have lower BMD Z-scores and BMD T-scores at an age close to their individual bone mass peak. Males treated with intensive therapy present with deteriorated bone health in the context of therapy-induced hypogonadism and low physical activity. The timely detection of low BMD, treating hormonal dysfunctions and increasing PA are effective means to preventing and delaying late morbidity.