Reduction of basal metabolic rate, energy expenditure and metabolic protein mass in women with breast cancer

Abstract

Breast cancer (BC) can appear with comorbidities like obesity and sarcopenia; however, it is not completely clear how they are related. The excessive adipose tissue can secret inflammatory cytokines and alter body metabolism, energy expenditure and cell function. Interestingly, a novel approach to evaluate body composition and cell membrane functionality by electrical bioimpedance is the measurement of the Phase Angle (PA), which is reduced in the presence of inflammation. The hypothesis of this study was that women with BC have higher fat mass as well as a lower PA and metabolism than women without cancer. We conducted a cross‐sectional study that included women 28‐74 years old (n=70), there were two groups, one had women with BC diagnosis (n=39) and one without it (n=31). Body composition was evaluated using 5 frequencies with a BiodyXPERT ZMII equipment. Blood glucose and lipids were also measured. Dietary patterns (DP) were obtained by Principal component analysis (PCA). The results (Table 1) showed that PA was not significantly different (p=0.067) between the BC (6.71 ± 0.56°) and the control (6.97 ± 0.61°) groups. However, women with BC had a significantly lower basal metabolic rate (1275.05 ± 73.71 Kcal vs 1334.57 ± 103.45 Kcal, p=0.009), energy expenditure (1843.87 ± 168.40 Kcal vs 1944.33 ± 208.31 Kcal, p=0.039) and metabolic protein mass (7.83 ± 1.21 Kg vs 8.62 ± 1.48 Kg, p=0.018) than control women. Cohen's d analysis showed these variables had a medium effect size. Crude fat mass, blood glucose, total cholesterol and triacylglycerols were not significantly different between the groups. Furthermore, we found three different DP (DP I, DP II and DP III) in both groups. Two of them were unhealthy: DP I (31.6%) was loaded heavily in fat cereals, high fat animal food, sutured fat and sweet beverages and DP II (38.0%) had a high factor load in moderate fat animal food, sweets and grain groups. Nonetheless, DP III was the healthy pattern (30.4%) and had a higher load of fruit, vegetables, cereals, very low fat animal food and dairy. Therefore, women with BC have a reduced basal metabolic rate, energy expenditure and metabolic protein mass, the last one is associated with altered skeletal muscle mass although this was not significantly altered in women with BC. Further analysis is necessary to examine the correlation between metabolic protein mass and dietary protein consumption. These parameters shall be monitored to improve BC prognosis.