Background: The well-documented increased cardiometabolic risk in haematopoietic stem cell transplantation and total body irradiation (HSCT/TBI) survivors is under-recognised using standard (International Diabetes Federation (IDF)) metabolic syndrome (MetS) criteria. This is defined as the presence of central adiposity using increased waist circumference (WC) or BMI, (often not abnormal in HSCT/TBI survivors despite increased central adiposity), plus additional features including two of following: ↑ triglycerides (TGs) >1.7 mmol/l, ↓ HDL (M <1.03 mmol/l and F <1.29 mmol/l), BP >130/85, and ↑ fasting glucose >5.6 mmol/l or known diabetes.
Objective: To identify alternative measures of central adiposity to define the MetS which are more representative of metabolic risk in HSCT/TBI survivors.
Method: Childhood leukaemia survivors treated with HSCT/TBI (1014.4 Gy; n=21, 10M) at mean aged 9.3 (1.010.8) years were compared with chemotherapy-only (n=31), and obese non-leukaemic controls (n=30). All subjects (1626 years) had BP and auxological measurements (BMI, waist, and hip circumferences) and blood tests (HDL, TG, and oral glucose tolerance tests). The prevalence of the MetS defined by ↑ waist-to-height (WHtR; >0.5) or waist-to-hip ratios (WHR) (M >0.9 and F >0.8) rather than standard criteria of WC (M >94 cm and F >80 cm) or BMI >30 kg/m2 were compared using odds ratios and ANOVA (5% significance).
Results: The HSCT/TBI group had two patients with diabetes and a higher prevalence of low HDL (57%) vs chemotherapy-only (27%), P=0.003; raised TG (48%) vs both chemotherapy-only (10%), P=0.005 and obese (13%, P=0.001) groups but significantly lower mean BMI (P<0.001), WC (P<0.001), WHtR (P<0.001) than the obese, and lower WHR (P=0.003) than the chemotherapy-only groups. There was no difference in the prevalence of the MetS using standard IDF criteria: HSCT/TBI (19%), chemotherapy-only (10%, P=0.4), and obese (17%, P=0.8) groups. When WC was replaced by WHtR, the prevalence increased to 38% in HSCT/TB, significantly higher than chemotherapy-only (13%, P=0.047) patients. Using WHR, HSCT/TBI prevalence was 43%, significantly higher than both chemotherapy-only (10%, P=0.011) and obese (17%, P=0.044) groups. The prevalence in the obese group remained unchanged with all three definitions.
Conclusions: The WHR is more representative of central adiposity allowing identification of metabolic syndrome and risk in HSCT/TBI survivors.
Funding: This work was funded by the IPSEN clinical research fellowship, BSPED research Award, David Telling Research funds, and Peel Medical research award.
01 Oct 2015 - 03 Oct 2015