HJAR Mar/Apr 2021

40 MAR / APR 2021 I  HEALTHCARE JOURNAL OF ARKANSAS CHILDREN’S HEALTH COLUMN CHILDREN’S HEALTH during the day. However, if the lights at school or home are dim during the day, the SCN can be fooled into thinking it’s dusk and begins secreting melatonin, causing fatigue. Secondly, during nightfall or dusk, the dimming light is supposed to trigger melatonin production. However, bright lights or electronic devices are often turned on, again fooling the SCN, this time thinking it is daytime and suppressing the production of melatonin. Research has found that the short-wavelength blue lights emitted from electronic devices also suppresses melatonin production1. These two light exposures can cause significant effects on the body’s circadian rhythm. Studies have shown that substantial shifts in the circadian rhythm can have adverse health effects, including chronic fatigue, depression and mood disorders. 2 ADEQUATE good-quality sleep is essential for human health. Sleep is not just the ab- sence of wakefulness but also an import- ant active process necessary for vital bodi- ly functions, including immunity, memory processing and consolidation, hormone secretion, emotional regulation and more. However, ever-changing societal norms or expectations and technological advances have made it difficult for humans to main- tain consistent sleep/wake cycles, leading to decreased sleep and increased health problems over the years. Also, in some individuals, sleep may be fragmented due to conditions like obstructive sleep apnea (OSA) or restless legs, making it nonrestor- ative. Lights, Circadian Rhythm and Adequacy of Sleep Everyone has a sleep/wake cycle, also known as the circadian rhythm. The cir- cadian rhythm is controlled by a center within the brain called the suprachiasmat- ic nucleus (SCN), via the neurohormone melatonin, which signals the body to be- come sleepy. Light falling on the retina of the eyes suppresses melatonin production, whereas darkness stimulates it. Before technological advances, the rising and set- ting of the sun predominantly cued mela- tonin levels. 1 As technology has evolved, work and school days have become longer with people spending increasingly more time indoors in front of electronic screens and under artificial lights. This affects the secretion of melatonin in two ways. First, the bright sunlight in the morning and bright lights in our homes and offices suppress melatonin’s secretion, making it easier to stay awake and be productive Supriya Jambhekar, MD Professor of Pediatrics University of Arkansas for Medical Sciences and Arkansas Children’s Hospital SLEEP: How Important Is It?