Impact of Sleep Quality and Sleep Duration on Cholesterol Levels

Josephine Owusu

NEURO 300

Dr. Morrison

Impact of Sleep Quality and Sleep Duration on Cholesterol Levels

Professional drivers, especially truck drivers, frequently experience harmful and unhealthy lifestyles and have elevated cardiovascular health risks. The global economy is to blame for their work conditions, because it requires industries to work round-the-clock under tight, controlled schedules. Their intermittent work schedule creates challenges to maintaining a healthy lifestyle, because it interferes with healthy nutritional habits as well as exercise, sleep, and social interactions. Their extensive and intermittent work hours are connected with sleep deprivation. Moreover, sleep quality and duration impact several features of health, such as, diabetes, hypertension, cardiovascular disease, and mortality.  

Quality and duration of sleep both have a significant influence cholesterol levels through various mechanisms. Cholesterol is transported throughout the body, binded by proteins called lipoproteins. Lipoproteins can be divided into two central types, high density lipoprotein(HDL) and low density lipoprotein(LDL). Too much of LDL cholesterol is unhealthy, therefore it is often classified as "bad cholesterol.” Whereas, HDL has protective properties, so it is often denoted as “good cholesterol.” Endocrine activity is affected by sleep, which then influences several metabolic operations by modifying levels of hormones such as cortisol and thyrotropin. Such health afflictions and diseases not only lead to considerable reduced longevity, or lifespan among long haul drivers, but also have deleterious effects on roadway safety and thereby affect the over-all motoring public. Thus, this present study has two main purposes: 1) to create and analyze a cholesterol outline for long haul drivers, and 2) to determine the relationship between sleep periods/durations, sleep quality, and cholesterol concentrations levels in the sample of long haul drivers (Lemke et. al, 2017).

The investigators collected data for work organization and workplace factors that could possibly be linked to cholesterol amongst long-haul truck drivers. The investigators used a descriptive cross-sectional survey to gather data from 262 long-haul truck drivers from a large truck stop in North Carolina. With the assistance from additional key instruments and related sleep literature, the investigators used the Trucker Sleep Disorders Survey that has been used in other relevant sleep studies. The Trucker Sleep Disorders Survey included questions that measured compensation type and daily work hours. In particular, compensation type and daily work hours were categorical question. For instance, drivers were asked “On average, how many hours do you work in a day?” The response choices for this question were: 6 or less hours; 7–8 hours; 8–9 hours; 9–10 hours; 10–11 hours; 11–12 hours; 12–13 hours; 13–14 hours; and more than 14 hours (Lemke et. al, 2017). In addition, the survey included questions that measured sleep quality and sleep periods/durations. In order to measure sleep periods, drivers were asked, “On average, how many hours of sleep do you get on your workdays?”.  Their answers were categorized in compliance with the National Sleep Foundation standard rules: ‘Short’ (<7hrs.); ‘Optimal’ (7–9 hrs.) and ‘Long’ (>9hrs.). The drivers were also asked how often they got adequate sleep at night using the subsequent response choices: never, rarely, almost every night, and every night (Lemke et. al, 2017).

In order to examine the blood cholesterol levels in the sample of long-haul truck drivers, the drivers were administered a blood test to measure LDL (mg/dL), HDL (mg/dL), non-HDL (mg/dL), and total cholesterol (mg/dL). The cholesterol levels were expressed in milligrams (mg) of cholesterol per deciliter (dL) of blood. Then, the investigators carried out a descriptive analysis of the cholesterol levels of LDL, HDL, non-HDL, and total cholesterol. Next, they performed a succession of linear regression analyses to assess for probable, prognostic connections amongst workplace factors, sleep quality, sleep periods/durations and cholesterol (HDL, LDL, and total cholesterol) results.

Results showed that when asked about the number of hours that the long-haul drivers actually slept on their workdays, the drivers reported receiving an average of 6 hours and 55 minutes of sleep on their workdays. However, on their non-workdays, they reported receiving an average of 8 hours and 16 minutes.

Many long-haul truck drivers demonstrate high-risk indicators for serious physical health conditions. These include, but are not limited too, high cholesterol and increased risk for heart disease. Approximately 66% of drivers had low HDL scores (<40 mg/dL), and approx. 42% had a high cholesterol to HDL cholesterol ratio. This indicates a two-fold increased risk for heart disease. Sleep quality of drivers was linked to HDL, LDL, and total cholesterol, while sleep duration was linked to LDL cholesterol. These findings reveal how sleep quality and sleep durations can produce detrimental effects on cholesterol levels.

Furthermore, the findings of this investigation concerning the impact of sleep quality and sleep periods/durations on cholesterol levels, have shown that insufficient sleep periods and quality is coupled with reduced HDL cholesterol levels, insufficient sleep quality also heightens the risk of cardiovascular disease, and that sleep disruptions increase cholesterol levels.

Similar to this experiment, Dr. Baura also presented research on sleep deprivation amongst long-haul drivers at Loyola’s Neuroscience seminar. In Dr. Baura’s presentation, she showed that truck drivers are at a high-risk for several health diseases (especially sleep apnea). She also revealed that long-haul truck drivers received approximately 5 hours of sleep per day, which is relatively close to the results in Lemke et. al study. Dr. Baura presented electroencephalograms from Mitler’s study which showed that drivers experiences episodes of stage 1 sleep while they were driving between the hours of 11 p.m. – 5 a.m (Mitler et. al, 1997). Both Baura’s presentation and Lemke’s investigation show that long-haul truck drivers are still a disregarded profession from a public health perceptive. In addition, Baura and Lemke’s investigations emphasize the need for stakeholders in healthcare to take action by implementing all-inclusive worksite health organizations. The public health sector and the haulage industry should recognize and address these issues, and joint action from both sides should be taken to treat drivers’ work conditions.   

Work Cited

Lemke, Michael & Apostolopoulos, Yorghos & Hege, Adam & Wideman, Laurie & Sönmez, Sevil. (2017). Work, Sleep, and Cholesterol Levels of U.S. Long-Haul Truck Drivers. Industrial Health. 55. 10.2486/indhealth.2016-127.

Mitler, M. M., Miller, J. C., Lipsitz, J. J., Walsh, J. K., & Wylie, C. D. (1997). The Sleep Of Long-Haul Truck Drivers. The New England Journal of Medicine,U.S. National Library of Medicine. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC243092/