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Sleep lab

The Wits Sleep Laboratory is part of the Brain Function Research Group, School of Physiology and is the only dedicated sleep research unit in Southern Africa. 

Founded in 1985 with a start-up 10-year sponsorship from a bedding manufacturer, Edblo (Africa), the Sleep Lab is equipped with 3 instrumented bedrooms, bathrooms, a kitchen as well as a large living area to improve the comfort of subjects. In addition to the computerised digital electroencephalograph (EEG), used to record sleep patterns, the Sleep Lab has facilities for measuring body temperature, metabolic rate, reaction times, blood pressure, oxygen saturation, circadian rhythms, and to complete jetlag/shiftwork experiments. It is adjacent to a well-equipped human Exercise Research Laboratory and has access to a climatic chamber.

The Wits Sleep Laboratory is a research entity investigating the nature and function of sleep. The staff does not carry out clinical consultations, however, they are happy to diffuse knowledge of sleep disorders.

Current Research:

  • Sleep, circadian rhythms and immune function
  • The relationship between sleep and pain
  • Sleep and exercise performance
  • Restless legs syndrome

Staff:
Dr Karine Scheuermaier
Dr Stella Iacovides

Honorary staff
 
Professor Duncan Mitchell
Dr Fiona Baker

For more information on the research activities in the Wits Sleep Laboratory, contact Dr Karine Scheuermaier (Karine.Scheuermaier@wits.ac.za)

IACOVIDES S, BAKER FC, AVIDON I, BENTLEY A

Women with dysmenorrhea are hypersensitive to experimental deep muscle pain across the menstrual cycle.

Journal of Pain 14: 1066-1076, 2013

 

Research Projects Available

Sleep disruption and autoimmunity in patients with rheumatoid arthritis

There is a known relationship between sleep and the immune system whereby sleep disruption has been shown to enhance inflammatory states, but conversely inflammatory states also lead to increased sleep disruption.

Rheumatoid arthritis is an auto-immune disorder which leads to the inflammatory destruction of joints usually starting in middle age then moving to a chronic condition. Activation of CD4+ T cells, B cells and macrophages lead to the progressive destruction of the joint architecture. 

A recent study in rheumatoid arthritis patients showed that self-reported sleep disruption increased with disease activity status. However, it remains unclear whether sleep disruption is correlated to pain itself and/or increased immune activation.

Preliminary data from the sleep laboratory showed that acute sleep deprivation disrupts the immune response, in particular, regulatory CD4+ T cells (Tregs) which help control the activation of CD4+ T cells. Another question which arises is whether sleep disruption may trigger/ worsen rheumatoid arthritis symptoms.

In this study, we are proposing to collect subjective sleep evaluations (through validated questionnaires) and objective sleep information, through activity data and polysomnography (overnight sleep recording) in rheumatoid arthritis patients while also measuring immune markers of the disease (rheumatoid factor) and general immune markers (CRP, certain cytokines), to which we would add measurements of CD4 activation/ CD4 Tregs in those experiencing flares.

The aims of this study are threefold:

1-     Describe the sleep characteristics in a population of rheumatoid arthritis patients (subjective –through questionnaires and objective – through activity measures and overnight sleep recording on a subset of patients) and compare those sleep characteristics in patients who are in a chronic state versus those who are experiencing flares.

2-     We will test the hypothesis that there is a positive relationship between sleep disruption and disease activity in this population.

3-     We will test the hypothesis that there is a positive relationship between sleep disruption and immune markers which may be modulated by pain.

Sleep disruption, hypertension and complications of pregnancy

Hypertension develops in 10% of pregnant women. The risk for preeclampsia, miscarriage and other pregnancy complications such as placenta abruptio, kidney failure or coagulation disorders is significantly enhanced in hypertensive pregnant women.

There is a known positive relationship between sleep disruption and hypertension. Sleep deprivation leads independently to metabolic complications such as metabolic syndrome, diabetes type II, hypertension and cardiovascular complications. Studies have shown that sleep becomes increasingly disrupted through pregnancy due to pregnancy –related events such as hormonal level modifications, higher oxygen demand, increase in size of the uterus which leads to a restrictive respiratory disorder and higher nocturia.

In this study, we propose to investigate the relationship between pregnancy-related sleep disruption and hypertension in pregnant women recruited from the Charlotte Maxeke obstetrics clinic.

Study objectives:

1-     Determine the prevalence of sleep disruption and hypertension in pregnant women during early and late pregnancy (first or second vs. last trimester)

2-     Test the hypothesis that sleep disruption is a risk factor for hypertension in pregnant women when adjusting for BMI.

3-     Measure blood markers of endothelial function and oxidative stress at different times of pregnancy to better characterize the pathophysiology which may underlie the relationship between pregnancy related sleep disruption and hypertension.

Sleep disruption complications in metabolic, cardiovascular & immune functions

How do the sleep disruption and circadian misalignment seen in shiftwork/irregular sleep wake schedules lead to disturbances in metabolic, cardiovascular and immune functions?

 

Sleep disruption and circadian rhythm misalignment (such as seen in shiftworkers) are known to affect several key physiological functions, eventually leading to a higher overall risk of metabolic syndrome, diabetes type II,  cardiovascular complications and cancer.

The first aim of this study is to follow up long term shiftworkers after different shift periods (days, afternoons, nights), obtain objective and subjective measures of sleep and circadian phase (ambulatory melatonin measurements) during and after these different periods, and measure markers of insulin resistance, endothelial and immune function.

The second aim of this study is to look at the long term (over several years) changes in metabolic, cardiovascular and immune markers in populations of shiftworkers.

The third aim is to specifically investigate the impact of an abrupt circadian phase shift (akin to jetlag) on targeted subpopulations of immune cells, using healthy volunteers.

These projects can be used individually for a Masters topic or can be taken together as part of a PhD.

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