Serum estrogen and androgen levels following treatment for cervical cancer.

Endogenous sex hormones seem to influence the risk of several common and debilitating diseases. With a view toward better understanding the effects of surgical removal of the ovaries and high-dose pelvic radiotherapy on plasma sex hormone levels, we measured estrogen and androgen concentrations cross-sectionally among 147 women who had been treated for cervical cancer 0.3-18.5 years previously. Pelvic radiotherapy (mean dose to ovaries, 50 Gy) and bilateral ovariectomy were associated with similarly reduced hormone concentrations relative to levels among nonirradiated women with intact ovaries, most of whom had had early-stage disease and were treated by hysterectomy. There was little evidence that radiotherapy in addition to ovariectomy further lowered concentrations below levels associated with ovariectomy alone, such as might be expected if radiation was suppressing adrenal endocrine function. Among women age 50 years or older at the time of blood drawing, the removal or irradiation of the ovaries was associated with approximately 45% lower concentrations of estradiol (mean ratio [MR], 0.55; 95% confidence interval [CI], 0.32-0.95) and testosterone (MR, 0.57; 95% CI, 0.32-0.99), and 25-30% lower concentrations of estrone (MR, 0.69; 95% CI, 0.44-1.09) and androstenedione (MR, 0.76; 95% CI, 0.47-1.23), relative to the hysterectomy-only group. Among women younger than 50, ovariectomy and radiotherapy, alone or in combination, were associated with 83% lower estradiol concentrations (MR, 0.17; 95% CI, 0.09-0.31), 46% lower estrone concentrations (MR, 0.54; 95% CI, 0.37-0.81), 23% lower androstenedione concentrations (MR, 0.77; 95% CI, 0.57-1.04), and 14% lower testosterone levels (MR, 0.86; 95% CI, 0.64-1.15).(ABSTRACT TRUNCATED AT 250 WORDS)

Impaired driving performance in shiftworkers: the role of the circadian system in a multifactorial model.

A substantial and growing percentage of the U.S. work force now works on a rotating shift schedule. The repeated changes in sleep-wake, meal and work times inherent in such schedules conflict with the dictates of the internal biological clock and have adverse consequences for the health of the shiftworker population. An important consequence of this conflict is impaired performance, both on and off the job, as indexed by the increased incidence of motor vehicle accidents in shift workers. In this paper we report the results of a survey administered to rotating shift and straight day workers at a manufacturing plant in the eastern U.S. This survey documents an increased incidence of motor vehicle accidents or "near misses" in which sleepiness was implicated as a cause by the respondent. Complaints of poor sleep and increased sleepiness were also significantly more common in shiftworkers than day workers. Last, shiftworkers reported higher caffeine and alcohol consumption, and were more likely to use alcohol as a sleep aid. Although causal links cannot be established using these associative observations alone, previously reported experience with alteration of shift schedules, improvement of levels of alertness, and reduction in adverse performance outcomes corroborate the possibility of a causal link and suggest potential interventions.

Chronotherapy: resetting the circadian clocks of patients with delayed sleep phase insomnia.

We report here the development of a brief drug-free rescheduling treatment ("chronotherapy") for Delayed Sleep Phase (DSP) insomnia, a syndrome characterized by sleep-onset insomnia with difficulty in morning awakening. We postulated that patients with DSP insomnia had an inadequate capacity to achieve phase advance shifts of the circadian pacemaker which times the sleep-wake cycle. Chronotherapy was therefore designed to reset these patients' biological clocks by the phase delay route. This single 5-6 day treatment was tested in 5 patients with a 4-15 year history of DSP insomnia. All 5 patients reported a lasting resolution of their symptoms substantiated by systematic long-term self-reports and objective polygraphic recording before and after treatment (average follow-up of 260 days; range, 42-910 days). The average sleep onset advanced from 4:50 a.m. before treatment to 12:20 a.m. afterwards, and wake times advanced from 1:00 p.m. to 755 a.m. (for both, p less than 0.001), with no reduction in sleep efficiency. As a result, all 5 patients were able to end their chronic dependence on hypnotic medications.