PLOD1 and myalgic encephalomeyelitis/chronic fatigue syndrome: A study comparing blood levels of luteinizing hormone (LH), follicle-stimulating hormone (FSH), estradiol, progesterone, and cortisol in premenopausal females diagnosed with CFS and paired healthy controls found no significant difference between CFS and fatigue-free patients for LH, FSH, estrogens, and progesterone, although CFS-diagnosed patients were shown to have significantly lower levels of cortisol [154].