NPPB and myalgic encephalomeyelitis/chronic fatigue syndrome: Significant positive correlation was found between the mean CFS score and the hospitalization period (r = 0.43, p < 0.01), CRP (r = 0.41, p < 0.01), UA (r = 0.25, p < 0.01), and BNP (r = 0.33, p < 0.01).