Shiftwork-Mediated Disruptions of Circadian Rhythms and Sleep Homeostasis Cause Serious Health Problems

Figure 1

The abnormalities associated with shiftwork. (1) Shiftwork primarily affects the circadian clock and leads to several disruptions and disorders. (2) Disruption in circadian clock further affects the circadian system and alters important gene expressions which play an important role in maintaining normal body functions. (3) BMAL1 and CLOCK genes are the key factors that control circadian rhythms. Any alteration in these groups of genes further alters the genetic expression of genes (Per 1–3 and Cry 1/2) involved in clock maintenance. Other factors and proteins which play a major role in circadian rhythm are RORs, REV-ERBs, CK1δ, CK1ε, AMPK, FBXL3 and βTRC. (4) Shiftwork either directly or through circadian system alterations may cause severe psychiatric disorders including major depression, anxiety, and mood disorders. (5) Due to exposure to light irregularly, shiftwork enhances the chances of breast cancer. Breast cancer development is promoted by sleep disruptions, circadian system imbalances, and dietary conditions. (6) Sleep disorders and disrupted sleep is another condition developed by shiftwork. (7) This disruption in sleep affects the metabolism and causes metabolic disorders including obesity.