Question: Diego García-Borreguero has completed fellowships in sleep medicine and sleep research at an agency founded when ?

Context paragraphs:
Sleep medicine: Sleep medicine is a medical specialty or subspecialty devoted to the diagnosis and therapy of sleep disturbances and disorders.  From the middle of the 20th century, research has provided increasing knowledge and answered many questions about sleep-wake functioning.  The rapidly evolving field has become a recognized medical subspecialty in some countries.  Dental sleep medicine also qualifies for board certification in some countries.  Properly organized, minimum 12-month, postgraduate training programs are still being defined in the United States.  In some countries, the sleep researchers and the physicians who treat patients may be the same people.

Emmanuel Mignot: Emmanuel Mignot (born 1959 in Paris) is a sleep researcher and director of the Stanford Center for Sleep Sciences and Medicine, at Stanford University.  Dr. Mignot is an authority on sleep research and medicine, and is mostly known for his work on narcolepsy.  He is the Craig Reynolds Professor of Sleep Medicine at Stanford Medical School, Stanford University.

Clete Kushida: Clete Anthony Kushida (born 1960) is a sleep medicine clinician and sleep scientist, a Professor in the Department of Psychiatry and Behavioral Sciences at the Stanford University Medical Center, Medical Director of the Stanford Sleep Disorders Clinic, and Director of the Stanford University Center for Human Sleep Research.

Diego García-Borreguero: Diego García-Borreguero, MD, PhD, is the Director of the Sleep Research Institute in Madrid, Spain.  Until 2005, he was Director of the Sleep Disorders Center at the Department of Neurology of the Fundación Jiménez Díaz (Autonomous University of Madrid).  He has completed fellowships in sleep medicine and sleep research at the National Institutes of Health in Bethesda, Maryland, USA and underwent residency training at the Max Planck Institute in Munich, Germany.  He received his MD from the University of Navarre (Pamplona, Spain) and completed his PhD at the University of Munich.

Journal of Clinical Sleep Medicine: The Journal of Clinical Sleep Medicine is a monthly peer-reviewed medical journal covering sleep medicine.  It was established in 2005 and is published by the American Academy of Sleep Medicine, of which it is the official journal.  The editor-in-chief is Nancy A. Collop (Emory University).  According to the 2016 "Journal Citation Reports", the journal has a 2016 Impact Factor of 3.429 and a 5-year Impact Factor of 4.067.

National Institutes of Health: The National Institutes of Health (NIH) is the primary agency of the United States government responsible for biomedical and public health research, founded in the late 1870s.  It is part of the United States Department of Health and Human Services with facilities mainly located in Bethesda, Maryland.  It conducts its own scientific research through its Intramural Research Program (IRP) and provides major biomedical research funding to non-NIH research facilities through its Extramural Research Program.

American Board of Sleep Medicine: The American Board of Sleep Medicine (ABSM) says in its website, "The [ABSM] is an independent, nonprofit organization whose certifications are recognized throughout the world as a credential signifying a high level of competence for sleep medicine physicians, PhDs, behavioral sleep medicine specialists and sleep technologists."  It shares office space and at least some staff with the American Academy of Sleep Medicine (AASM) at 2510 N. Forntage Rd., Darien, Illinois 60561.  The two organizations are closely related and serve basically the same constituency.

Sleep (journal): Sleep is a monthly peer-reviewed medical journal covering research on sleep.  It is the official journal of the Associated Professional Sleep Societies and sponsored by the American Academy of Sleep Medicine and the Sleep Research Society.  The journal was established in 1978 and the editor-in-chief is David Dinges (University of Pennsylvania School of Medicine).

William C. Dement: William Charles Dement (born July 29, 1928) is a pioneering US sleep researcher and founder of the Sleep Research Center at Stanford University.  He is a leading authority on sleep, sleep deprivation and the diagnosis and treatment of sleep disorders such as sleep apnea and narcolepsy.  For this pioneering work in a previously uncharted field in the United States, he is sometimes referred to as the American father of sleep medicine.

International Classification of Sleep Disorders: The International Classification of Sleep Disorders (ICSD) is "a primary diagnostic, epidemiological and coding resource for clinicians and researchers in the field of sleep and sleep medicine".  The ICSD was produced by the American Academy of Sleep Medicine (AASM) in association with the European Sleep Research Society, the Japanese Society of Sleep Research, and the Latin American Sleep Society.  The classification was developed as a revision and update of the Diagnostic Classification of Sleep and Arousal Disorders (DCSAD) that was produced by both the Association of Sleep Disorders Centers (ASDC) and the Association for the Psychophysiological Study of Sleep and was published in the journal Sleep in 1979.  A second edition, called ICSD-2, was published in 2005.  The third edition, ICSD-3, was released in 2014.

Supporting paragraphs: Diego García-Borreguero National Institutes of Health
Answer: in the late 1870s