Obesity linked to dangerous sleep apnea in truck drivers

Truck crashes are a significant public health hazard, causing thousands of deaths and injuries each year, with driver fatigue and sleepiness being major causes. A new study by Harvard researchers has confirmed previous findings that obesity-driven testing strategies identify commercial truck drivers with a high likelihood of obstructive sleep apnea (OSA) and suggests that mandating OSA screenings could reduce the risk of truck crashes.

“Truck drivers with sleep apnea are much more likely to fall asleep at the wheel, and the condition is increasingly common as Americans become more obese,” said the study’s senior author, Stefanos N. Kales, a Harvard Medical School assistant professor of medicine and medical director of employee and industrial medicine at Cambridge Health Alliance, where the study was conducted. “Additionally, we found that drivers who suffer from obstructive sleep apnea frequently underreport symptoms and diagnoses and often do not follow through with sleep study referrals and sleep apnea treatment.”

OSA is a syndrome characterized by sleep-disordered breathing, resulting in excessive daytime sleepiness, sleep attacks, psychomotor deficits, and disrupted nighttime sleep. It increases the risk of a vehicular accident by two- to sevenfold, and is common among truck drivers. Approximately 2.4 million to 3.9 million licensed commercial drivers in the Unites States are expected to have OSA.

In addition to being unrecognized or unreported by drivers, OSA often remains undiagnosed by many primary care clinicians despite the fact that OSA increases the risks of hypertension, diabetes mellitus, and heart disease.

Over the 15-month study period, 456 commercial drivers were examined from over 50 different employers. Seventy-eight (17 percent) met the screening criteria for suspect OSA.

These drivers were older and more obese, and had a higher average blood pressure. Of the 53 drivers who were referred for sleep studies, 33 did not comply with the referral and were lost to follow-up. The remaining 20 were all confirmed to have OSA, but, after diagnosis, only one of these 20 drivers with confirmed OSA complied with treatment recommendations. “It is very likely that most of the drivers who did not comply with sleep studies or sleep apnea treatment sought medical certification from examiners who do not screen for sleep apnea and are driving with untreated or inadequately treated sleep apnea,” said Kales.

The study, published by the Journal of Occupational and Environmental Medicine, has significant policy ramifications, as the Federal Motor Carrier Safety Administration is currently deliberating recommendations to require sleep apnea screening for all obese drivers based on body mass index, or “BMI.”

The administration requires medical certification of licensed commercial drivers at least every two years. These occupational medicine exams present a unique opportunity for detecting OSA as part of determining a driver’s safety behind the wheel.

“OSA screenings of truck drivers will be ineffective unless they are federally mandated or required by employers,” said Kales, who is also an assistant professor at the Harvard School of Public Health. The study’s authors also support the prohibition of “doctor shopping.” Kales said, “Such action would prohibit drivers diagnosed with a serious disorder that might limit driving or require treatment to seek out more lenient or less rigorous medical examiners.”