Biomedical subjects

François Vandenhende

Publications and source records attributed to François Vandenhende.

4 recordsLinked to original sources

PubMed2006

Major depression in males: effects of age, severity and adaptation on sleep variables.

Sleep abnormalities have been repeatedly demonstrated in major depression. However, the respective influences of age, severity, adaptation and gender have never been clearly disentangled. In a retrospective study, full polysomnograms of 67 male depressive patients and 67 carefully age-matched male healthy control subjects were analyzed. The usual differences associated with the sleep of depressed patients were observed. However, in contrast to most reports, REMS was also found to be reduced; although no comparisons between sexes can be made in this all-male study, one interpretation of this finding is that reduction of REMS is a marker of male depression. Age was found to influence most sleep variables, but not the order of their association with depression. Depression severity was found to be associated with Wake After Sleep Onset (WASO), REMS, and Non-REMS (NREMS). No residual adaptation effect was observed. One of the main markers of depression was in fact the absence of sleep, whether observed as long delays prior to entering sleep, or excessive intermittent awakenings. This sleep reduction affected both REMS and NREMS, in comparable percentages. This supports the hypothesis of a hyperarousal possibly linked to stress.

Adaptation, Psychological↗

PubMed2004

Comparative effects of duloxetine and desipramine on sleep EEG in healthy subjects.

RATIONALE: Antidepressants are known to modify human sleep patterns. OBJECTIVES: Duloxetine is a new antidepressant with a mechanism of action involving reuptake inhibition of both serotonin (5-HT) and norepinephrine (NE). In this study, the effects of two dosing regimens of duloxetine on sleep electroencephalography (EEG) were investigated at steady-state plasma concentrations in young, healthy, male subjects. METHODS: Placebo (n=12), desipramine (50 mg BID; n=12) and two regimens of duloxetine (80 mg QD, n=6; or 60 mg BID, n=6) were compared in a randomized, double-blind, three-period crossover study, each treatment being administered from day 1 to day 7. Sleep polygraphic recordings took place at baseline (day -1) and day 6 of each period. The Leeds sleep evaluation questionnaire (LSEQ) was also administered on the morning of day 7. RESULTS: Both regimens of duloxetine produced a significant increase in the onset latency of REM sleep as well as a significant mean decrease in total REM sleep duration. Desipramine exhibited comparable effects. When compared to placebo, sleep continuity was significantly reduced with desipramine and duloxetine 60 mg BID whereas a significant improvement was observed with duloxetine 80 mg QD. On the LSEQ, duloxetine 80 mg QD produced a significant improvement in the "getting to sleep" subscale compared to placebo, whereas desipramine demonstrated a significant reduction (worsening) in the "quality of sleep" score versus placebo. CONCLUSIONS: The two dose regimens of duloxetine (80 mg QD and 60 mg BID) produced a REM sleep pattern comparable to that of most antidepressant medications. Duloxetine 80 mg QD appeared to exhibit less impact upon sleep quality than duloxetine 60 mg BID in healthy subjects.

Adolescent↗

PubMed2002

A copula-based model for multivariate non-normal longitudinal data: analysis of a dose titration safety study on a new antidepressant.

A new model for multivariate non-normal longitudinal data is proposed. In a first step, each longitudinal series of data corresponding to a given response is modelled separately using a copula to relate the marginal distributions of the response at each time of observation. In a second step, at each observation time, the conditional (on the past) distributions of each response are related using another copula describing the relationship between the corresponding variables. Note that there is no need to consider the same family of distributions for these response variables. The technique is illustrated in a dose titration safety study on a new antidepressant. The haemodynamic effect on diastolic blood pressure, systolic blood pressure and heart rate is studied. These three responses are measured repeatedly over time on ten healthy volunteers during the dose escalation. The available covariates are sex and the concentration of drug in the plasma at time of measurement.

Antidepressive Agents↗

PubMed2002

On the joint analysis of longitudinal responses and early discontinuation in randomized trials.

Our focus is on the joint analysis of longitudinal nonnormal responses and early discontinuation in (pre)-clinical trials. Separate models are fitted to the two series (response and discontinuation) to account for covariate and time effects. The serial dependence and the dependence between response and drop-out are also modeled. This is done using particular dependence functions, called copulas. Copulas are used to create a joint distribution with given marginal distributions. Applications are given for the analysis of heart rate/morbidity in toxicology and pain severity/intake of rescue medications in a trial on migraine. Using copulas, the level of dependence between two variables remains invariant to changes in the marginal distribution of either variable. This proves interesting in modeling the association in a longitudinal setting when responses change over time.

Algorithms↗