Among the 280 who were frail by CFS, 177 (63.2%) were taking agents acting on the renin-angiotensin system, 119 (42.5%) beta blockers, 94 (33.6%) diuretics, 71 (25.4%) calcium blockers, and 25 (8.9%) anti-adrenergic agents. Here, REN is linked to myalgic encephalomeyelitis/chronic fatigue syndrome.