Author(s): ZARDO, W., MORIGGI, T., VILLA, E., CORTI, E., PELI, L., BALDUZZI A., LANFRANCONI, F. , Institution: FONDAZIONE MONZA E BRIANZA PER IL BAMBINO E LA SUA MAMMA, Country: ITALY, Abstract-ID: 2362

INTRODUCTION:
Cancer is the leading cause of death from non-communicable diseases in children, adolescents and young adults with cancer (CAYA-C) in Europe. Reduced exercise capacity in CAYA-C may reflect both bed rest and drug-induced side effects such as cardiopulmonary dysfunction and/or reduced skeletal muscle oxidative metabolism due to myopathy and peripheral nervous system impairment. The individuals reduced exercise capacity in complex clinical situations, i.e. during the intensive phases of CAYA-C treatment, can be assessed by cardiopulmonary exercise testing (CPET). During CPET, near-infrared spectroscopy (NIRS) measures muscle oxidative capacity in vivo at the vastus lateralis and physiological calibration using an ischaemic leg cuff manoeuvre is required to compare different individuals. The leg cuff maneuver is not an option in CAYA-C with cancer due to severe thrombocythemia. The aim of this pilot study was to test whether adapted NIRS physiological calibrations obtained by quadriceps isometric and isotonic exercise manoeuvres can be performed in CAYA-C instead of the classical leg-cuff ischaemia.
METHODS:
After CPET on a cyclergometer, ischaemia of the quadriceps was performed on 3 CAYA-C with blood cancer (age 16.0±3.0 years) by means of isometric and isotonic exercises on a leg extension machine (80% of 1 maximum repetition). Each manoeuvre was separated by 2 minutes of rest and the difference between the values at rest and at the end of the manoeuvres was calculated, until a plateau of deoxygenated hemoglobin values was reached (D[HHb], A.U.). In 3 healthy young adults (HEAL) the 2 methods were compared with a 300 mmHg leg cuff tourniquet and the D[HHb] kinetic time (τ, sec) was measured. The D[HHb] values obtained during CPET were expressed as a percentage of the different ischaemias (D[HHb]/D[HHb]isch).
RESULTS:
None of the CAYA-C patients complained of pain during the manoeuvres, although the HEAL patients experienced discomfort during the leg-cuff. The 3 CAYA-C showed D[HHb] 19.1±2.8 and 16.8±2.7 in relation to isometric and isotonic conditions respectively, without any statistical difference. The D[HHb]/D[HHb]isch were 0.38±0.08 and 0.34±0.07 in relation to isometric and isotonic conditions, respectively. The 3 HEAL showed D[HHb] 10,1±6,5, 9,3±9,8 and 11,7±9,0 in relation to isometric, isotonic and leg cuff conditions respectively without any statistical difference. The τ of the 3 procedures were 36,8±21,0, 23,1±22,9 and 249,8±133,7 respectively with a significant statistical difference (p<0,006)
CONCLUSION:
The adapted physiological NIRS calibrations were well tolerated in both CAYA-C and HEAL. Reduced oxidative metabolism was observed in CAYA-C and comparable D[HHb] values were found between isometric and isotonic manoeuvres. HEAL showed that the kinetics of the leg cuff is slower than other manoeuvres and give reasons for the pain experienced during the manoeuvres, adding concern in performing the manoeuvre in CAYA-C.