Effects of Shifting Schedules to Circadian Rhythm - Essay Example

? Effects of Shifting Schedules to Circadian Rhythm Laura Walker First/Second Semester, Section> Outline ofthe Paper: I. Introduction II. Review of Related Literature III. Discussion of Findings A. Effects of Shift Work on Circadian Rhythm B. Dangers of Shift Work IV. Conclusion V. Works Cited Laura Walker 1 May 2011 Effects of Shifting Schedules to Circadian Rhythm I. Introduction A person’s sleep patterns are partly determined by one’s biological clock, or in more technical terms, one’s circadian rhythm (Miller 65). The term circadian traces back its roots to the Latin words circa, which means around, and dies, which means day. It refers to biological processes in plants and animals that repeat in 24-hour cycles (American Heritage Dictionary of the English Language (3rd ed.)). Indeed, the most obvious function of circadian rhythms in humans is the sleep/wake cycle, wherein adults generally tend to become sleepy between 10 PM and midnight and to awaken feeling rested between 6 AM and 8 AM. Research indicates that poor sleeping quality contributes to a myriad of illnesses such as hypertension, cardiac arrest, stroke, hyperthyroidism, and eventual fatality (Shneerson 102). Considering the detrimental effects that poor quality sleep and irregular sleeping patterns cause, it is important to know what factors contribute to the disruption of the body’s circadian rhythm. In particular, this paper would like to investigate if engaging in shifting schedules is among the factors that contribute to the disruption of the body’s circadian rhythm. II. Review of Related Literature Circadian rhythm is just one of the many periodic cycles that the human body adheres to. Other periodic events in the human body include ultradian rhythms, women’s menstrual cycle, and circannual rhythms that are present in both males and females. Circadian rhythms are “caused by oscillators situated in the cell nuclei with a number of genes participating and creating a translational–transcriptional feedback system in which some gene products accumulate and inhibit the clock gene function, followed by a release of gene function when the gene products are removed metabolically out of the feedback cycle” (Haus & Smolensky 491). Studies show that certain social, cultural, and industrial developments have disrupted this supposedly regular body cycle. For one, the development of the light bulb has radically changed people’s sleep patterns because the artificial light that a light bulb emits fools the body into thinking that it is daylight and thus contributes to the phenomenon of people staying up late at night and waking up late in the morning (Moore-Ede 157). In addition, the intake of caffeine and alcohol has also affected the quality of sleep that people enjoy. Large doses of caffeine are found to increase the heart rate and stimulate the brain and behavior (Nordegren 54). On the other hand, alcohol intake briefly causes drowsiness and is thus used by some people to initiate sleep. However, tolerance to its hypnotic effect often leads to an increase in the amount being ingested until sleep-wake patterns are totally disrupted in the end (Shneerson 105). Changes in today’s lifestyle also entails that people no longer engage in “normal working hours.” Harrington defines normal working hours in such a way that the individual works during the day and rests during the night, with some time left for recreation and other activities (58). People who do not engage in normal working hours tend to either work at night, on with extended hours or on shifts, thus violating the regular pattern of working at day and resting at night. In particular, three generally followed shifting schedules are the night shift which starts at 2200 hours, the morning shift which begins at 0600 hours, and the afternoon shift which typically commences at 1400 hours (Harrington 59; Akerstedt 90). Akerstedt further specifies that these different shift schedules also have different effects on the body’s sleep-wake cycle (90). III. Discussion of Findings A. Effects of Shift Work on Circadian Rhythm All existing pieces of literature point to the conclusion that engagement in shifting work schedules adversely affects a person’s circadian rhythm (Moore-Ede; Gold, Rogacz & Bock; Harrington; Akerstedt; Knutsson; Haus and Smolensky). Shifting work schedules disrupts the regular cycle that the body has adapted to and thus causes other irregularities in the body’s physiological functions as well. In effect, shifting work schedules produces a phase shift in the regular circadian rhythm of an indivdual. With this, there is a produced effect in the metabolizing and proliferating cells in the individual. This effect leads to the the condition where the molecular level functions and the cellular oscillations of the individuals are no longer in sync with each other (Haus & Smolensky 491). It should likewise be noted that once the body’s circadian rhythm is interrupted, it usually takes more than a couple of cycles more before the body regains its original rhythm (Gold, Rogacz & Bock 1012). This largely explains why people who stayed up late all night takes more than a couple of regular nights’ sleep to get rid of their generally drowsy and lethargic feeling. B. Dangers of Shifting Schedules Akerstedt mentions in his paper that engagement in shift work highly correlates with cases of cardiovascular diseases, gastrointestinal diseases, increased risk of accident involvement, sleep disturbances, and increased cases of fatigue (89). This result is supported by findings of Gold et al from a hospital-based survey which they carried out among 635 Massachusetts nurses. The survey covered engagement in shift work, sleep patterns, and involvement in accidents among these nurses. They found out that when compared to nurses who were assigned to a regular day only or evening only schedule, those who were engaged in rotating shifts experienced more incidences of sleep/wake cycle disruption and also tended to nod off more frequently at work (Gold, Rogacz and Bock 1013). Moreover, they also found that those who engaged in rotating shifts nodded off more frequently while driving and were involved in more cases of a reported accident or sleepiness-related error compared with their colleagues who were engaged in a regular schedule (Gold, Rogacz and Bock 1013). Figure 1 as adapted from Knutsson (106) shows a graphic representation of exactly how engagement in shifting schedules leads to the development of diseases in individuals engaging in such an activity. He explains that engagement in shifting work schedules leads to a mismatch of the individual’s circadian rhythm, disturbances in the individual’s socio-temporal patterns, and changes in the individual’s behavior (Knutsson 105). With these effects, the individual may thus experience internal desynchronization, increased susceptibility to diseases, sleep / wake disturbances, social insufficiency, and stress. All these factors will now contribute to the development of diseases in the affected individual (Knutsson 106). Figure 1. Development of Disease Resulting from Shiftwork Knutsson further specifies the different diseases that are heavily associated with engagement in shift work such as gastrointestinal disease, cardiovascular disease, cancer, improper pregnancy outcomes, and aggravated existing medical conditions (103). He takes the conservative route in correlating shift work with mortality and states that as of yet, no sufficient evidence exists to associate the two (Knutsson 103). IV. Conclusion Indeed, there is an overwhelming amount of evidence which indicates that shifting schedules do have an effect on the body’s circadian rhythm. This finding is significant because as outlined in this paper, disruptions on a person’s circadian rhythm causes health problems and may even lead to eventual fatality. Thus, it should be well worth noting that people refrain from subjecting themselves to shifting work schedules as much as possible. Moreover, this finding ought to provide human resource personnel or other pertinent departments enough reason to refrain from giving shifting work schedules to their personnel. As shown in this paper, subjecting a person to a shifting work schedule leads to a number of health problems. Moreover, they tend to make more errors, poorer decisions, and crucial accidents. In the end, both the individual and the institution he or she belongs to will be at a losing end when shifting work schedules are practiced. As such, a regular and uninterrupted circadian rhythm may significantly contribute to a person’s well-being. V. Works Cited Akerstedt, Torbjorn. "Shift Work and Disturbed Sleep / Wakefulness." Occupational Medicine 53 (2003): 89 - 94. American Heritage Dictionary of the English Language (3rd ed.). MA: Houghton Mifflin Company, 1992. Gold, DR, et al. "Rotating Shift Work, Sleep, and Accidents Related to Sleepiness in Hospital Nurses." American Journal of Public Health 82.7 (1992): 1011 - 1014. Harrington, JM. "Health Effects of Shift Work and Extended Hours of Work." Occupational and Environmental Medicine 58 (2001): 68 - 72. Haus, Erhard and Michael Smolensky. "Biological Clocks and Shift Work: Circadian Dysregulation and Potential Long-Term Effects." Cancer Causes Control 17 (2006): 489 - 500. Knutsson, Anders. "Health Disorders of Shift Workers." Occupational Medicine 53 (2003): 103 - 108. Miller, Carol. Nursing for wellness in older adults. Philadelphia, PA: Lippincott Williams & Wilkins, 2009. Moore-Ede, MC. "Jet lag, Shift Work, and Maladaptation." News in Physiological Sciences 1 (1986): 156 - 160. Nordegren, Thomas. The A-Z encyclopedia of alcohol and drug abuse. Universal Publishers, 2002. Shneerson, John. Sleep medicine: a guide to sleep and its disorders. John Wiley & Sons, 2005. Read More