Near infrared spectroscopy (NIRS) as a new non-invasive tool to detect oxidative skeletal muscle impairment in children survived to acute lymphoblastic leukaemia

Abstract

Background: Separating out the effects of cancer and treatment between central and peripheral components of the O2 delivery chain should be of interest to clinicians for longitudinal evaluation of potential functional impairment in order to set appropriate individually tailored training/rehabilitation programmes. We propose a non-invasive method (NIRS, near infrared spectroscopy) to be used in routine clinical practice to evaluate a potential impairment of skeletal muscle oxidative capacity during exercise in children previously diagnosed with acute lymphoblastic leukaemia (ALL). The purpose of this study was to evaluate the capacity of skeletal muscle to extract O2 in 10 children diagnosed with ALL, 1 year after the end of malignancy treatment, compared to a control group matched for gender and age (mean±SD = 7.8±1.5 and 7.3±1.4 years, respectively).

Methods and findings: Participants underwent an incremental exercise test on a treadmill until exhaustion. Oxygen uptake ([Formula: see text]), heart rate (HR), and tissue oxygenation status (Δ[HHb]) of the vastus lateralis muscle evaluated by NIRS, were measured. The results showed that, in children with ALL, a significant linear regression was found by plotting [Formula: see text] vs Δ[HHb] both measured at peak of exercise. In children with ALL, the slope of the HR vs [Formula: see text] linear response (during sub-maximal and peak work rates) was negatively correlated with the peak value of Δ[HHb].

Conclusions: The present study proves that the NIRS technique allows us to identify large inter-individual differences in levels of impairment in muscle O2 extraction in children with ALL. The outcome of these findings is variable and may reflect either muscle atrophy due to lack of use or, in the most severe cases, an undiagnosed myopathy.

Conflict of interest statement

Competing Interests: The authors have declared that no competing interests exist.

Figures

Figure 1. Individual and mean values of body mass index percentile (BMI) in ALL (n = 10) and CTRL (n = 10) children.

Statistical significance level was defined as p

Figure 2. Individual and mean values of relative to predicted in ALL (n = 10) and CTRL (n = 10) children.

Statistical significance level was defined as p

Figure 3. Individual skeletal muscle O2 extraction, Δ[HHb], expressed as the ratio of the values obtained during limb ischemia, are presented for children with ALL as a function of speed.

CTRL values (thick line) are shown as mean±SE. Speed is expressed relative to peak value. Statistical significance level was defined as p

Figure 4. Regression between and skeletal muscle O2 extraction at peak of exercise, Δ[HHb] peak, expressed as the ratio of the values obtained during limb ischemia for children with ALL (n = 10).

CTRL values are shown as mean±SE. Statistical significance level was defined as p

Figure 5. Individual regression for heart rate (HR) vs the corresponding for one ALL and one CTRL child (A graph).

Regression between the individual slopes of the HR vs relationship, obtained in children with ALL (n = 10) and skeletal muscle O2 extraction at peak of exercise Δ[HHb]peak, expressed as the ratio of the values obtained during limb ischemia with the corresponding regression line (B graph). CTRL values are given as mean±SE. Statistical significance level was defined as p<0.05.