Michèle Dramaix

The first-night effect may last more than one night

The first-night effect in sleep polysomnographic studies is usually considered to last for one night. However, a few observations have indicated that variables associated to rapid eye movement sleep take longer to stabilize. Notwithstanding, current opinion holds that second nights of recording can be used without restriction for research and clinical purposes. The goal of this study was to describe the dynamics of habituation to polysomnography in optimal conditions. Twenty-six young, carefully screened, healthy subjects were recorded in their home for four consecutive full polysomnographies. Repeated measures ANOVA were applied. Between the two first nights, while there were no differences in sleep duration in non-rapid eye movement sleep, marked modifications in corresponding spectral power were observed. The dynamics of adaptation of rapid eye movement sleep appeared to be a process extending up to the fourth night. Similar dynamics in NREMS and REMS homeostasis have been observed in sleep deprivation studies, and it appears that the same mechanisms may be responsible for the FNE. The longer habituation process of REMS in particular has important implications for sleep research in psychiatry.

Ankle/arm pressure index in asymptomatic middle-aged males: an independent predictor of ten-year coronary heart disease mortality.

Purpose of the study: to evaluate the predictive power of a reduced ankle/brachial pressure index (ABPI) (≤ .90) in an asymptomatic middle-aged male working population free of coronary heart disease. Materials and Methods: 2023 subjects forty to fifty-five years old were screened at their work place. Standard techniques were used. Blood was drawn in the fasting state. Ankle and brachial blood pressures were measured by Doppler signals and all measures were done by one observer, duly trained in epidemiologic methodology Results: in univariate analysis, an ABPI ≤ .90 was significantly associated with age, total serum cholesterol, body mass index, smoking, and awareness of diabetes. In multi- variate analysis, it was associated with awareness of diabetes, age, Ln triglycerides (P=.073), and smoking (P=.088). Relative risks for reduced versus normal ABPI are 2.77 (P=.010), 4.16 (P=.011) and 4.97 (P=.006) for ten-year all causes, cardiovascular, and coronary mortality, respec tively. In a multiple logistic regression analysis, the following variables were significant independent predictors of coronary mortality: smoking (odds ratio [OR] =4.84), reduced ABPI (OR=3.63), and low density lipoprotein cholesterol (OR for 1 SD=1.69). Reduced ABPI is also an independent predictor of cardiovascular mortality Conclusion: a reduced ABPI is an independent risk factor for coronary and cardio vascular mortality in asymptomatic middle-aged Belgian males.

Influence of Maternal Smoking on Autonomic Nervous System in Healthy Infants

To determine the influence of maternal smoking on autonomic nervous system in healthy infants, 36 infants were recorded polygraphically for one night. Their mothers were defined, according to their smoking frequency during pregnancy, as “nonsmokers” (no cigarettes smoked during pregnancy) or “smokers” (10 or more cigarettes per day). The infants had a median postnatal age of 10.5 wk (range 6 to 16 wk); 18 were born to nonsmokers, and 18 to smokers. During the whole night, spectral analyses of heart rate (HR) were evaluated as a function of sleep stages. Two major peaks were recognizable: a low-frequency component (LF) related to sympathetic and parasympathetic activities and a high-frequency component (HF) reflecting parasympathetic tonus. The ratio of LF/HF powers was calculated as an index of sympathovagal interaction. In REM sleep, “smokers” infants were characterized by significantly lower HF powers and normalized HF powers, and higher LF/HF ratios than “nonsmokers.” The finding did not reach statistical significance in NREM sleep. In conclusion, maternal smoking induced changes in autonomic control and maturation in infants. These effects of cigarette smoke exposure can be added to those already reported and offer additional evidence for counseling mothers to stop smoking.

Episiotomy and third‐degree tears

Summary. The relation of episiotomy to third‐degree perineal tears was investigated in 21 273 singleton deliveries. The incidence of episiotomy was 28.4% (n=6041). Third‐degree tears occurred in 14% (85) of the deliveries with episiotomy and in 0.9% (132) of the deliveries without episiotomy (P<0.01). To avoid the effect of confounding factors, we analysed a sub‐sample that included only vertex presentations with spontaneous occipitoanterior vaginal deliveries. After stratification for birthweight and parity, no relation between episiotomy and third‐degree tear was found.

Is obesity associated with injuries among young people

Objectives: To look at the relationship between obesity and trauma among young people in the Hainaut Province in Belgium. Design: A cross-sectional study (questionnaire and physical examination) was conduced among a sample of 2363 children of 9- to 17-year-olds (n = 2363) in 1998. Results: In the past 12 months prior to the survey, 37% of the sample had at least one injury requiring treatment (with or without hospitalization), and 5% had a severe injury (with at least one night at the hospital). More than 15% were classified to be obese according to the WHO definition. We observed a significantly higher frequency of injury in obese people, in boys, in subjects playing sport intensively, with members of a sports club and in those reporting more than one physical activity per week. In multivariate analysis for injury, gender, physical activity, playing sport in a club and obesity were significant. For severe injuries, only gender and physical activity remained significant in the multivariate analysis. Conclusion: Our analysis shows that childhood obesity and physical activity increase the occurrence of injuries. However, we did not observe an association between obesity and severe injuries. Obesity as a risk factor for the occurrence of injuries has to be confirmed by other studies, and the understanding of the mechanism for the observed association needs more investigation.

Clinical and psychosocial predictors of recurrence in recovered bipolar and unipolar depressives: A one-year controlled prospective study

Unipolar and bipolar patients with a chronic illness pattern were investigated to evaluate the relevance of clinical and psychosocial risk factors to predict subsequent recurrence. Self-esteem, social adjustment, social support and attributional style were assessed in 27 recovered bipolar patients, 24 recovered unipolar patients maintained on lithium or antidepressant prophylaxis and 26 healthy controls. They were further interviewed every 2 months in a 1-year period in order to diagnose affective episodes according to Research Diagnostic Criteria. Survival analyses and Coxs regressions demonstrated that being a unipolar patient and showing poor social adjustment were the strongest predictors of the occurrence of affective episodes. Self-esteem, social support, attributional style and clinical characteristics, such as age at illness onset, number of previous episodes or of previous hospitalizations and presence of affective disorder in first-degree relatives, were not found to be risk factors for further recurrence. This study stresses the importance of social adjustment in evaluating the outcome of affectively ill patients maintained on medication prophylaxis.

Screening for refractive errors in children: accuracy of the hand held refractor Retinomax to screen for astigmatism

AIMS To assess the reliability of the hand held automated refractor Retinomax in measuring astigmatism in non-cycloplegic conditions. To assess the accuracy of Retinomax in diagnosing abnormal astigmatism in non-cycloplegic refractive screening of children between 9 and 36 months. METHODS Among 1205 children undergoing a non-cycloplegic refractive screening with Retinomax, 299 (25%) had repeated non-cycloplegic measurements, 302 (25%) were refracted under cycloplegia using the same refractor, and 88 (7%) using retinoscopy or an automated on table refractor. The reproducibility of non-cycloplegic cylinder measurement was assessed by comparing the cylindrical power and axis values in the 299 repeated measurements without cycloplegia. The influence of the quick mode on cylinder measurement was analysed by comparing the cylinder and axis value in 93 repeated measurements without cycloplegia where normal mode was used in one measurement and quick mode in the other. Predictive values of the refractive screening were calculated for three different thresholds of manifest astigmatism (⩾1.5, ⩾1.75, and ⩾2 D) considering as a true positive case an astigmatism ⩾2 D under cycloplegic condition (measured by retinoscopy, on table, or hand held refractor). RESULTS The 95% limits of agreement between two repeated manifest cylinder measurements with Retinomax attained levels slightly less than plus or minus 1 D. The 95% limits of agreement for the axis were plus or minus 46°. The comparison of non-cycloplegic measurements in the quick and normal mode showed no significant difference and 95% limits of agreement plus or minus 0.75 D. The mean difference between non-cycloplegic and cycloplegic cylinder values measured by Retinomax reached 0.17 D and was statistically significant. Manifest thresholds of ⩾1.5 D, ⩾1.75 D, ⩾2 D cylinder value diagnosed 2 D of astigmatism under cycloplegia respectively with 71–84%, 59–80%, 51–54% of sensitivity (right eye-left eye) and 90–92%, 95%, 98% of specificity. CONCLUSION Without cycloplegia, Retinomax is able to measure cylinder power with the same reproducibility as cycloplegic retinoscopy. No significant difference was found in the cylinder values obtained with the quick and the normal modes. Therefore, the quick mode of measurement is recommended as it is more feasible in children. No difference, which is significant from a screening point of view, exists between the non-cycloplegic and the cycloplegic cylinder value (<0.25 D). Retinomax diagnoses abnormal astigmatism (⩾2 D) in a non-cycloplegic refractive screening at preschool ages with 51–84% sensitivity rates and 98–90% specificity rates, depending on the chosen threshold of manifest astigmatism. If 2 D of manifest astigmatism is chosen as a positive test, the positive predictive value of the screening reaches 81–84% and the negative predictive value 91–90% (right eye-left eye).

Job stress and major coronary events: results from the Job Stress, Absenteeism and Coronary Heart Disease in Europe study.

Aims The intention of this study is to investigate the relationship of the demands/control/strain model with hard coronary events in an epidemiological, prospective, multicenter, European study. Methods and results Six cohorts (Brussels, Ghent, Lille, Barcelona, Göteborg and Malmö) from four European countries (Belgium, France, Spain and Sweden) consisting of 21 111 middle-aged male subjects participated between 1993 and 1996 in the baseline survey of the Job Stress, Absenteeism and Coronary Heart Disease in Europe (JACE) study. The Karasek strain model of psychological demands (five items)/control (nine items) was used. During a mean follow-up of 40 months 185 acute coronary events or coronary deaths were observed. Age-adjusted hazard ratios (HRs) for developing an acute coronary event were 1.46 [CI 95% confidence interval (1.08–1.97)] for high against low psychological demands and 1.53 (95% CI 1.0–2.35) for strained (high demands plus low control) against relaxed (low demands plus high control) groups. After adjustment for standard cardiovascular risk factors the HR for developing a coronary event for those above or equal to the median against those below the median of psychological demands was 1.46 (95% CI 1.08–1.97) whereas the HR for strained against relaxed groups is 1.46 (95% CI 0.96–2.25). Sensitivity analyses confirmed the robustness of the results. Conclusion In this European, multicenter, prospective, epidemiological study the Karasek job strain model was an independent predictor of acute coronary events, with the psychological demands scale emerging as the important component.

Screening for abnormal levels of hyperopia in children: a non-cycloplegic method with a hand held refractor

AIMS High hyperopia constitutes the majority of refractive errors in large scale visual screening at preschool ages. The authors aimed to assess the validity of the Retinomax hand held refractor to detect high hyperopia in a refractive screening performed without cycloplegia and carried out on children aged 9–36 months. They considered +1.5 D of manifest hyperopia to be the threshold value and abnormal absolute hyperopia to be above +3.5 D. METHODS Of the 897 children screened without cycloplegia, 220 were refracted with cycloplegia. The validity of several thresholds of manifest hyperopia was estimated by receiver operating characteristic (ROC) curves using cycloplegic measures as a reference. The reproducibility of Retinomax measurements was assessed. Normal and quick mode measurements were compared using the Wilcoxon test. RESULTS The manifest threshold of +1.5 D offered the best combination of sensitivity (70.2%), specificity (94.6%), positive predictive value (78.6%), and negative predictive value (91.9%) to disclose abnormal absolute hyperopia. A good agreement was obtained between the various measurements using Retinomax on the same subject. In the results of this survey, there is no evidence that accommodation is minimised in the normal mode of measurement compared with the quick mode. CONCLUSION The Retinomax hand held infrared autorefractor is a suitable instrument to diagnose abnormal hyperopia (manifest hyperopia >+1.5 D) in non-cycloplegic refractive screening at preschool ages. It is suggested as the quick mode of measurement as it is more feasible in children (success rate 98.5%).

Working conditions predict incidence of long-term spells of sick leave due to depression: results from the Belstress I prospective study

Background: During the last few years, a high incidence of sick leave due to depression has been reported, resulting in important economic and social impacts. Only a limited number of studies investigating the influence of psychosocial working conditions on sick leave have been prospective and have utilised a valid methodology, while none have studied sick leave due to depression. In this study, the impact of adverse psychosocial working conditions is analysed on the risk for long-term sick leave due to depression. Methods: This study resulted from the large-scale Belstress I study on the relationship between perceived job stress and health problems. Subjects were Belgian employees selected from 11 large companies (n = 9396). Using a longitudinal design, the association between the three Karasek stress dimensions (job control, psychological demand, and social support) was explored, separately and combined according to the demand–control and demand–control–support models and the incidence of long-term sick leave for depression as diagnosed by the family physician. Results: After adjusting for age, occupational categories, living situation, and baseline depression score, ‘passive jobs’ (OR 2.67; 95% CI 1.15 to 6.19) and ‘high strain’ jobs (OR 3.23; 95% CI 1.40 to 7.43) predicted sick leave due to depression at follow-up in men. Job control predicted sick leave due to depression in both men (OR 2.43; 95% CI 1.27 to 4.66) and women (OR 2.21; 95% CI 1.05 to 4.68). Conclusions: This study provides evidence that the psychosocial working environment influences long-term sick leave due to depression. Efforts to improve skill discretion and decision authority at work could help prevent depression.