Endocrine Abstracts

Introduction: Childhood cancer survivors (CCS) are at risk of vitamin D (VitD) deficiency because of chronic ill health and advice to limit sunlight exposure. Studies have demonstrated associations between VitD deficiency and cardiovascular disease. Some CCS has increased risk of cardiovascular morbidity, but data on VitD status are limited.

Aim: To evaluate VitD status in CCS.

Method: We compared VitD levels in CCS (n=83 (M=42)) with controls of non-oncological endocrine patients (n=232 (M=112)). CCS included patients with solid cancers (SC; n=43) and haematological malignancies (HM; n=40) of whom 28 received BMT and 22 total body irradiation (TBI). Total 25-hydroxylase-VitD levels <25, <50 and 50–75 mmol/l were defined as severely deficient, deficient and suboptimal respectively. Patients with primary bone disease, malabsorption or VitD supplementation were excluded.

Results: (Mean±S.D.) unless stated. There were no differences in the season of testing, gender, weight, height, or BMI-standard-deviation-scores (SDS) between the CCS and controls. CCS were older (14.7 (5.1) vs 10.3 (5.0) years, P<0.001), with more caucasians (92.8 vs 80.2%, P=0.008). Weight-SDS was lower in HM (−0.746 (2.05)) than SC (0.486 (1.72), P=0.003) or controls(−0.001 (2.01), P=0.03). VitD deficiency was more common (53 vs 48%) and levels lower (geometric mean (GM)=44.3 vs 48.6 mmol/l) in CCS compared with controls although not statistically significant. Sub-analysis demonstrated significantly lower VitD levels in HM compared with controls (GM=38.4 vs 48.6 mmol/l, P=0.003). This remained significant after correcting for age and weight-SDS (P=0.004). HM had significantly higher incidence of VitD levels below suboptimal (92.8 vs 79.3%, P=0.037) and more BMT patients had severe deficiency (25 vs 11.2%, P=0.038) compared with controls. VitD deficiency was more common in TBI patients after excluding non-Caucasians (65 vs 41.4%, P=0.043). Age correlated negatively with VitD levels in SC(r=−0.349, P<0.05) and controls (r=−0.225, P<0.001), but not HM. Weight, height and BMI-SDS correlated negatively with VitD levels in controls, but not CCS. VitD deficiency was more common in winter months and non-Caucasians in all groups (P<0.05).

Conclusion: VitD deficiency is common in CCS, particularly HM. With its potential impact on cardiovascular health, VitD screening should be undertaken and supplementation actively considered as advice to minimise sunlight exposure is standard in CCS.