Assessment of sleep and circadian rhythm disorders in the very old: the Newcastle 85+ Cohort Study.

OBJECTIVES: to examine the association between subjective and objective measures of sleep and wake and other health parameters in a cohort of the very old. DESIGN: a population-based cohort study. SETTING: primary care, North East England. PARTICIPANTS: four hundred and twenty-one men and women, aged 87-89, recruited to the Newcastle 85+ Study cohort. METHODS: sleep questionnaires were administered and sleep-wake patterns were assessed over 5-7 days with a novel wrist triaxial accelerometer. Associations between sleep measures and various health parameters, including mortality at 24 months, were examined. RESULTS: only 16% of participants perceived their sleep as severely disturbed as assessed with questionnaire responses. Wrist accelerometry showed marked variation between normal and abnormal sleep-wake cycles that did not correlate with the participants' perception of sleep. Impaired sleep-wake cycles were significantly associated with cognitive impairment, disability, depression, increased falls, body mass index and arthritis but not with any other specific disease markers and with decreased survival. CONCLUSIONS: commonly used sleep questionnaires do not differentiate well between those with objectively determined disturbance of sleep-wake cycles and those with normal cycles. Abnormal sleep-wake patterns are associated with institutionalisation, cognitive impairment, disability, depression and arthritis but not with other diseases; there is also an association with reduced survival.

Is there any circadian variation consequence on acute case fatality of stroke? Takashima Stroke Registry, Japan (1990-2003).

BACKGROUND: Circadian periodicity in the onset of stroke has been reported. However, it is unclear whether this variation affects the acute stroke case fatality. Time of the day variation in stroke case fatality was examined using population-based stroke registration data. METHODS: Stroke event data were acquired from the Takashima Stroke Registry, which covers a stable population of approximately 55,000 in Takashima County in central Japan. During the period of 1990-2003, there were 1080 (549 men and 531 women) cases with classifiable stroke onset time. Stroke incidence was categorized as occurring at night (midnight-6 a.m.), morning (6 a.m.-noon), afternoon (noon-6 p.m.), and evening (6 p.m.-midnight). The 28-day case fatality rates and 95% confidence intervals (95% CI) were calculated by gender, age, and stroke subtype across the time blocks. After adjusting for gender, age at onset, and stroke severity at onset, the hazard ratios for fatal strokes in evening, night, and morning were calculated, with afternoon serving as the reference. RESULTS: For all strokes, the 28-day case fatality rate was 23.3% (95% CI:19.4-27.6) for morning onset, 16.9% (95% CI:13.1-21.6) for afternoon onset, 18.3% (95% CI:13.6-24.1) for evening onset, and 21.0% (95% CI:15.0-28.5) for the night onset stroke. The case fatality for strokes during the morning was higher than the case fatality for strokes during afternoon. This fatality risk excess for morning strokes persisted even after adjusting for age, gender, and stroke severity on onset in multivariate analysis. CONCLUSION: In the examination of circadian variation of stroke case fatality, 28-day case fatality rate tended to be higher for the morning strokes.

Characteristics of circadian rhythm in patients with intracerebral hemorrhage before death.

OBJECTIVE: To investigate characteristics of circadian rhythm in intracerebral hemorrhage before death. METHODS: This retrospective study was carried out from September 2002 to February 2009. One hundred and twenty-two dead cases with intracerebral hemorrhage(ICH) were collected. The study was carried out in the Department of Neurosurgery in The Second Affiliated Hospital of Guangdong Medical College, Zhanjiang, Guangdong, China. Blood pressure (BP) and heart rate (HR) were recorded every half-hour during the 72 hours before death. Data of BP and HR before deaths were divided into 3 time periods, namely, period A (72-48 hours to death), period B (48-24 hours to death), and period C (24 hours to death). Data from the 3 periods were analyzed using the Cosinor method to determine whether circadian rhythm was present or absent. The cases were divided into a present and absent group after Cosinor analysis. Prognostic factors in the 2 groups were analyzed by Student`s t-test and Pearson`s chi-squared test. RESULTS: Significant differences in prognostic factors between the 2 groups were not found. When circadian midline-estimating statistic of rhythms over the 3 periods were compared, there were no significant differences. However, when circadian amplitudes over the 3 periods were compared, the amplitudes during period C were significantly lower than period A or B (p<0.001). The percentage of cases in the absent and present groups was significantly different (p<0.001) over the 3 periods. CONCLUSION: As an independent factor, circadian variation could predict death in patients with ICH.

Shift work, confounding and death from ischaemic heart disease.

OBJECTIVE: To investigate the relation between shift work and death from ischaemic heart disease (IHD) and evidence for confounding by social class and healthy shift worker effects. METHODS: A case-referent study nested within an industrial cohort was used. Cases (n = 635) were cohort members who died of ischaemic heart disease (ICD 410-414) during 1950-98 aged 75 or under. Referents were matched on age and year of starting work at the site and were alive at time of case's death. Shift work status was determined from historical personnel records and pre-employment weight, height, blood pressure and smoking from medical records. Social class at first employment was inferred from job titles. To overcome potential bias due to a healthy shift worker hire effect, odds ratios were calculated from survivors 10 years after hire. To control for any healthy shift worker survivor effect, they were adjusted for duration of employment and time since termination of employment. Conditional logistic regression analysis was used to estimate ORs. RESULTS: 55% of subjects had worked as shift workers. Shift workers were more likely than day workers to belong to social class IV or V. The OR for shift workers compared with day workers, after adjustment for pre-employment risk factors, duration of employment and restricted to those who survived 10 years after hire was 1.11 (90% CI 0.90 to 1.37). This reduced to 1.04 (90% CI 0.83 to 1.30) after inclusion of social class. No dose-response relation was found. CONCLUSION: No excess risk of death from IHD for shift workers was found. The potential for confounding by social class in this relatively homogeneous cohort underlines the need to consider such confounding in more heterogeneous populations.

Lack of circadian variation in the activity of the autonomic nervous system after major abdominal operations.

OBJECTIVE: Most sudden postoperative deaths occur during the night and we conjectured that this was associated with circadian variations in the autonomic nervous tone, reflected in heart rate variability. DESIGN: Prospective clinical study. SETTINGS: University hospital, Denmark. SUBJECTS: 44 patients who had had major abdominal operations. INTERVENTIONS: Patients were monitored with 24-hour Holter ECG on the second postoperative day-evening-night. We calculated heart rate variability from the standard deviation of all normal R-R intervals (excluding ectopics-NN intervals) around the mean NN interval for the period of measurement (SDNN), the root mean square of the standard deviation of the differences between NN intervals (RMSSD), the percentage of NN intervals differing by more than 50 msec from adjacent NN intervals (pNN50) and the coefficient of component variance (meanNN/SDNN). MAIN OUTCOME MEASURES: Heart rate and heart rate variability. RESULTS: Circadian variation calculated from the SDNN (p = 0.43) the pNN50 (p = 0.11), the RMSSD (p = 0.47), and mean NN:SDNN ratio (p = 0.13) was absent postoperatively. Circadian variation in the heart rate was present but was set on a higher level compared with reference values. CONCLUSION: After major abdominal operations there was a lack of circadian variation in the autonomic nervous tone.