Karyn O'Keeffe

Dr Karyn O'Keeffe has been working in sleep for over 10 years now. She started her career as a Clinical Sleep Physiologist at WellSleep, University of Otago Wellington, where she diagnosed and initiated treatment in those with sleep disorders. After five years of rotating shift work, including nights, she was keen for a new challenge, so found herself in two half-time roles at two universities – at both WellSleep and the Sleep/Wake Research Centre – while completing her PhD (yes, insane). A few years ago, she moved away from a clinical role entirely and now works full-time as a Research Fellow at the Sleep/Wake Research Centre at Massey University.

Caffeine affects the circadian body clock - Sleep on it

Sep 22, 2015

It has long been known that drinking coffee close to bedtime can increase the time that it takes to fall asleep and change the structure of our sleep.  It was thought that these effects were primarily mediated through caffeine’s alerting properties; it binds adenosine receptors which causes the release of excitatory neurotransmitters.  Research published this month in Science Translational Medicine by Tina Burke and colleagues has shown that caffeine consumed close to bedtime can also affect the functioning of our circadian body clock. The circadian body clock is a small group of cells found in the hypothalamus in the brain, which regulates our ’24-hour’ processes, or circadian rhythms.  These include fluctuations in core body temperature, release of some hormones, and sleep/wake timing.  In order to know what time of day it is, the clock receives cues from the outside world.  The … Read More

Insufficient sleep increases your chance of developing a common cold - Sleep on it

Sep 02, 2015

Most of us would happily avoid the nuisance of having a head cold.  A new study published by Prather and colleagues in the journal Sleep this month has demonstrated that short sleep is associated with increased susceptibility to the common cold.  While recent research has highlighted that insufficient sleep is associated with susceptibility to infectious diseases, most research has investigated the impact of sleep on the immune system by partially or completing depriving people of sleep in the laboratory. In 2012, Cohen and colleagues studied sleep in a community setting and demonstrated that short sleep duration and poor quality sleep predicted the development of a cold following viral exposure.  They measured sleep by phoning people each day and asking them to recall their bed and rise times, and the number of minutes of sleep ‘lost’ during the sleep period due … Read More

Beliefs about normal sleep - Sleep on it

Mar 24, 2015

Having an understanding of what normal sleep looks like helps us identify when we are experiencing worrying sleep difficulties. Anecdotally, many people believe that good healthy sleep involves one solid period of sleep from lights out to waking in the morning.  Recently, a group of Australian researchers tested this hypothesis by asking a group of young (18-25 years) and older (60 years and older) to draw what they thought normal sleep looks like on a ‘Sleep Plot’ for an 18 year old’s and a 65 year old’s sleep.  An example of the plot is displayed below.  Individuals in each group were asked to draw one continuous line across the normal night time sleep period that indicated the transition between different sleep stages across the night.  What would you draw? A substantial majority of people (69%) drew a single … Read More

World Sleep Day 2015 - Sleep on it

Mar 12, 2015

This Friday, 13 March, is World Sleep Day, an event organised each year by the World Association of Sleep Medicine to highlight the importance of sleep to health and wellbeing.  This year’s slogan is ‘when sleep is sound, health and happiness abound.’ Sleep is a common issue for New Zealanders.  In a survey of 10,000 New Zealanders drawn at random from the electoral role, more than a third (37%) felt that they never or rarely got enough sleep.  30.1% of Māori and 24.4% of non-Māori reported getting than 7 hrs each night. In a survey of 4,000 New Zealanders drawn at random from the electoral role, 27% reported having a current sleep problem and 25% reported having a sleep problem that had lasted more than 6 months.  Women, older individuals, the unemployed and those with lower socioeconomic position were more … Read More

Teenagers and electronic devices: Use at night affects sleep - Sleep on it

Nov 26, 2014

Anyone with teenagers will know that they prefer to go to bed later and get up later than most adults. This pattern occurs as a result of biological changes to the timing of their circadian body clock, which shifts later relative to the day/night cycle. These changes can make it difficult for teenagers to fall asleep at a time that allows them to get enough sleep before they need to wake. On school days, when they are required to wake early, sleep may be cut substantially short. These biological changes are exacerbated by a number of factors, such as increasing independence in social interaction, setting of bedtimes, and use of electronic devices. The presence of electronic devices in the bedroom is associated with later bedtimes, shorter sleep and increased daytime sleepiness. Additionally, exposure to bright light from the screens of … Read More

Can we sleep more efficiently? - Sleep on it

Aug 11, 2014

Most of us have days when we wish there were a few more hours to get things done.  The solution proposed seems relatively straightforward, cut sleep short and sleep more efficiently.  Right? It is suggested that one way to achieve this might be with polyphasic sleep.  However, from a scientific point of view, polyphasic sleep has little merit. Polyphasic sleep involves sleeping in multiple bouts across each 24 hour day and potentially doing away with consolidated sleep at night.  A number of different patterns exist for polyphasic sleeping.  These range from the fairly benign (sleeping predominantly at night with an afternoon nap) to the more extreme (sleeping in three 1.5 hour naps across a 24 hour period or 6-8 20-minute naps across a 24 hour day, for example). Proponents claim that by sleeping in small frequent bouts, you will be … Read More

False memories after sleep deprivation - Sleep on it

Jul 29, 2014

Last week I read a cool study about false memories after sleep deprivation.  Published the week before in Psychological Medicine, the study was comprised of several experiments which examined whether sleep deprivation was associated with creation of false memories of witnessing a plane crash or after being fed misinformation. The researchers asked 193 undergraduate students to complete a questionnaire that contained a description of a well-known plane crash*, which stated that video footage of the crash had been widely viewed on the internet (although no such footage existed).   In addition to this, the students were asked to view two series of photographs, after which they were provided with a narrative for each that put the photos into context.  However, each student was randomly provided with one accurate narrative and one that contained three pieces … Read More

World Sleep Day - Sleep on it

Mar 14, 2014

Every year on the third Friday of March is World Sleep Day – a day when we aim to educate others about the importance of sleep and promote ways of getting good, healthy sleep. Each year also has a theme, such as “good sleep, good aging”, “sleep well, grow healthy” and “drive alert, arrive safe”. This year’s theme is “restful sleep, easy breathing, healthy body”. Restful sleep = healthy body Good sleep is about getting enough sleep, of good quality, at the right time of day. So how much sleep do we need? Studies show that adults need about 7-9 hours sleep each night. Less than 7 hours sleep has immediate effects: poor decision making, less creativity, slow reaction times, poor motor function, poor mood, and increased relationship conflict. In the long term, … Read More

Sleep disorders in New Zealand teenagers - Sleep on it

Dec 09, 2013

Last week saw media reports stating that, alarmingly, almost 40% of New Zealand teenagers have a sleep disorder. This stemmed from a Royal New Zealand College of General Practitioners press release, and a paper published in the Journal of Primary Health Care. At face value, these findings are very concerning indeed. The study surveyed 1388 Auckland high school students, from six different schools, using the authors’ Auckland Sleep Questionnaire. Drawing from the International Classification of Sleep Disorders, this questionnaire aims to assess a number of sleep problems commonly seen in primary care, and their potential underlying causes. An algorithm is then used to diagnose insomnia, obstructive sleep apnoea, parasomnias, delayed sleep phase disorder, medical problems, substance problems, and mood disorders.** As an example, the criteria used to determine whether an individual has a sleep problem are outlined below. These are … Read More

Food cravings and sleep - Sleep on it

Sep 10, 2013

Some of you may have seen or heard last month’s news reports stating that when we are sleep deprived, we crave junk food.  These reports stemmed from a study conducted by Stephanie Greer and her colleagues at the University of California, Berkeley, which investigated changes in brain function after one night’s sleep deprivation, compared to a preceding night of healthy sleep.  The researchers found that not only are the areas of our brain that make complex decisions impaired when we are sleep deprived, but there is more brain activity in the areas that control desire.  When participants were shown a series of food images and asked to rate their desire for each item, they preferred high calorie foods, like burgers and pizzas. Greer’s study adds to a growing body of work in this area and an increasing understanding of how … Read More