The patients with frailty (CFS ≥ 5) were older and had a lower body mass index (BMI), lower serum magnesium levels, lower albumin levels and higher C-reactive protein (CRP) levels; in addition, more patients had comorbidities of diabetes and cardiovascular diseases and a history of fractures among those patients with frailty. Here, CRP is linked to myalgic encephalomeyelitis/chronic fatigue syndrome.