JOURNAL REVIEWS
JOURNAL REVIEWS
Wright SW, Lawrence LM, Wrenn KD, et al. Randomized clinical trial of melatonin after night-shift work: Efficacy and neuropsychologic effects. Ann Emerg Med 1998; 32:334-339.
Melatonin apparently has no beneficial effect on the sleep cycles of shift workers, according to research from Vanderbilt University Medical Center in Nashville, TN.
Melatonin has received considerable attention as a home remedy for sleeping difficulties, but there has been little research so far to substantiate any effect. These researchers studied the effects of melatonin by trying to measure any effects on emergency physicians using melatonin and working intermittent night shifts.
They conducted a randomized, placebo-controlled, double-blind, crossover trial in the hospital’s emergency department. Fifteen emergency physicians were administered 5 mg of melatonin or a placebo for three consecutive nights after night-shift duty with crossover to the opposite agent after a subsequent block of night shifts. In measuring the possible effects, the researchers considered the primary indicator to be the global assessment of recovery measured by a visual analog scale.
Other measurements included sleep quality, duration of sleep, and fatigue. Participants also underwent neuropsychologic testing and completed a questionnaire about their mood.
There was no difference between the melatonin and placebo groups in any of the measurements. No adverse effects were noted, but the researchers point out that the study was not designed to detect adverse effects. They conclude that, despite the hype and anecdotal evidence of benefit, melatonin offers no benefit to the sleeping and alertness patterns of shift workers.
Garfinkel MS, Singhal A, Katz WA, et al. Yoga-based intervention for carpal tunnel syndrome. JAMA 1998; 280:1,601-1,604.
Yoga is an effective way to treat carpal tunnel syndrome (CTS), according to these researchers from the University of Pennsylvania School of Medicine in Philadelphia and other institutions.
CTS usually is treated with wrist splints, anti-inflammatory agents, job alteration, injection therapy, and surgery. Because those therapies leave many patients without substantial relief, researchers studied the effects of a program of yoga and relaxation techniques. They suspected the stretching may relieve compression in the carpal tunnel, better joint posture may decrease intermittent compression, and blood flow may be improved to decrease ischemic effects on the median nerve.
They studied 42 employed and retired people with documented CTS. Half of the patients underwent a yoga-based intervention consisting of 11 yoga postures designed for strengthening, stretching, and balancing each joint in the upper body along with relaxation given twice weekly for eight weeks. The other patients acted as a control group and were offered a wrist splint to supplement their current treatment programs.
At the end of the study, subjects in the yoga group had significant improvement in grip strength and pain reduction. The subjects in the control group had no significant improvement in those areas. The yoga group also had significantly more improvement in Phalen’s sign, with 12 improved vs. only two improved in the control group. There were no significant differences in either group regarding sleep disturbances, Tinel's sign, median nerve motor conduction, and sensory conduction time.
The subjects maintained improvement in their symptoms for four weeks after the yoga classes ended. The researchers say yoga might be a simple, noninvasive, inexpensive way to treat CTS. They suggest that "programs could be initiated at workplaces with a high incidence of CTS, perhaps with two classes per week for eight to 10 weeks, with monthly follow-up sessions to monitor home practice."
Yamasaki F, Schwartz JE, Gerber LM, et al. Impact of shift work and race/ethnicity on the diurnal rhythm of blood pressure and catecholamines. Hypertension 1998; 32:417-423.
Working second and third shifts may affect the way a person’s blood pressure "dips" during sleep, this study concludes. Most people normally experience a dip in blood pressure when they sleep at night, but shift work can alter the pattern so that people never experience that drop in pressure at any time during the day.
That can be detrimental to shift workers, say researchers at The New York Hospital-Cornell Medical Center. People who do not experience that drop in blood pressure can be at greater risk of heart disease than those whose blood pressure shows the normal fluctuations, the researchers say. African-American workers appear to be least likely to experience a diurnal blood pressure dip during shift work, which puts them at the greatest risk.
The researchers studied 93 nurses: 58 day-shift workers and 35 evening- and night-shift workers. Those working the late shifts had higher systolic blood pressure and experienced a smaller drop in systolic blood pressure during sleep than those working the day shift. Those working the evening and night shifts were six times as likely to be "nondippers" as the day-shift workers.
It is possible that the nondipping was affected the quality of the workers’ sleep. The evening and night-shift workers tended to sleep longer than the day shift workers, possibly to compensate for poor quality sleep. "Higher sleep blood pressure may contribute to the known adverse effects of shift work," the researchers conclude.
The researchers also studied the effects of shift work on the levels of stress hormones. Measure-ments of the stress hormones in the workers’ urine suggested that the hormones, which normally dip at night like blood pressure, also remain constant when the subject works irregular hours. The researchers suggest that the constant level of stress hormones is another indication of the adverse effects of shift work.
Papgeorgiou AC, Croft PR, Thomas E, et al. Psychosocial risks for low back pain: Are these related to work? Ann Rheumatic Diseases 1998; 57:500-502.
Psychosocial factors, such as general unhappiness with one’s economic situation or social life, can triple the likelihood of low back pain, according to this report from the University of Man-chester in England. On the other hand, actual employment may not have a lot of influence on low back pain because there appeared to be no difference in the incidence between employed and unemployed people.
The researchers studied 2,715 local residents with no existing low back pain. They interviewed them about whether their income was adequate to meet their needs and whether they were satisfied with their employment or non-employment. They were followed over the next year and watched for any episodes of low back pain.
The researchers found that dissatisfaction with work status doubled the risk of reporting a new low back pain episode in both the employed and non-employed. Those who said their income was inadequate were at a threefold increased risk of reporting low back pain, regardless of whether they were employed.
"Psychosocial factors pose similar risks for a new low back pain episode in workers and the non-employed," the study notes. "This suggests that such influences may not be related solely to work but may be a function of general aspects of life. The economic and individual impact of psychosocial interventions in the workplace, therefore, are likely to be limited unless account is taken of the influence of broader non-work related aspects."
Hlatky MA, Boothroyd D, Horine S, et al. Employment after coronary angioplasty or coronary bypass surgery in patients employed at the time of revascularization. Ann Internal Med 1998; 129:543-547.
The time a person is likely to spend on the job after heart surgery is most influenced by nonmedical factors such as the source of health insurance rather than the type of procedure performed, say researchers at the Stanford (CA) University School of Medicine and colleagues at other institutions.
They studied the effects of different surgical approaches on the amount of time spent on the job after surgery but found that the surgical choice had little effect. The researchers analyzed patterns of employment for 409 employed people with coronary artery disease, with all undergoing coronary angioplasty or coronary bypass surgery.
A large portion of the workers returned to work, with 82% in both groups returning to the workplace. Those undergoing angioplasty, the less invasive procedure, returned to work an average of six weeks earlier than those undergoing bypass surgery. Four years later, the type of surgery had little influence on whether the patient was still on the job.
The likelihood of long-term employment after surgery was influenced more by the patients’ age, what type of work they did, and whether they had private health insurance.
Subscribe Now for Access
You have reached your article limit for the month. We hope you found our articles both enjoyable and insightful. For information on new subscriptions, product trials, alternative billing arrangements or group and site discounts please call 800-688-2421. We look forward to having you as a long-term member of the Relias Media community.