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MASSEY
is published by Massey University, Private Bag 11-222, Palmerston North, New Zealand


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The magazine for alumni and friends of Massey University.
Issue 14, April 2002


Professor Philippa Gander
Professor Philippa Gander and the Sleep/Wake Research Centre

Tired, listless, crabby? So who isn’t? New Zealanders, like most of the civilised world, are chronically sleep-deprived, an affliction that probably owes much to the light switch.

“ Most species on this planet have some kind of internal time-keeping system that keeps them functioning in step with the day/night cycle, and this is known as the circadian clock. We don’t function the same way physiologically or psychologically across the 24-hour period. Your brain is programmed to be asleep at night so it functions quite differently from during the day,” explains sleep expert Professor Philippa Gander.

“ Up until the industrial revolution and the widespread availability of artificial light, people largely slept during the night and were awake during the day. Now more and more of us are trying to work against that.”

When Gander and the Sleep/Wake Centre surveyed 10,000 adults drawn at random from the electoral roll, 37 percent said they rarely or never got enough sleep. Another Centre survey, this one of insomnia, found 29 percent of Mäori and 25 percent of non-Mäori reported having a chronic sleep problem.

“ We know experimentally that if you deprive people of sleep, even only a few hours a night, you certainly change their waking function. They are sleepy. They tend to be more irritable. They are slowing progressively in terms of their reaction time, in terms of their cognitive processing, in terms of their psychomotor coordination,” says Gander.

Sleepy, irritable, slow. It has just turned 10. I monitor my own cognitive processing, reaction times, and psychomotor coordination and reach for the coffee. Philippa Gander has very brown eyes, a direct gaze, a mirth that sometimes tugs at one corner of her mouth, and she is very, very awake.

Serendipity is the word Gander applies to her career. In her first year at Auckland University the former Rotorua Girls’ High School pupil had hit on molecular biology as her future; in her second she was waylaid by a zoology course in ‘social behaviour and timing’. The course was fascinating, the teacher – later her supervisor– exceptional. “I decided I was much more interested in biological rhythms and circadian clocks.”

Her Master’s thesis examined circadian rhythms in wetas. Sometimes referred to as invertebrate mice after the ecological niche they occupy, wetas indeed turned out to have similar circadian clocks to rodents. Gander also mathematically modelled how the clock mechanism might work at the cellular level. “People were very familiar with cellular oscillation, but no one could imagine how an oscillation took place over 24 hours; how, with the mechanics of a cell, you could generate a 24-hour periodicity.” The model she worked on looked at “diffusion processes and synthesis in the nucleus, delayed feedback, those kinds of things in very general terms”. It would later reveal itself as remarkably accurate.

For her Doctorate she turned to the kiore, or Polynesian rat. Every year the kiore (Rattus exulans) of Tiritirimatangi Island began breeding over the same two-week period. Her zoological colleagues thought this might have to do with seedfall. Gander, who looked at the breeding patterns of kiore in their whole range, decided it had to do with day length “because they have a nice latitudinal cline in their breeding season”. In the laboratory she confirmed her suspicions by taking juvenile females and exposing them to different lengths of light cycle to bring them into oestrus or set their activity patterns.

It was with a year still to go on her PhD that Gander was made aware of an ad in Science for a job at Harvard, looking at the neuroanatomy of the circadian system in mammals, particularly primates. It was, she says “the dream job so far as I was concerned”. And Harvard must have liked her too, for they held the job for her until her graduation in 1980. “I got a Fulbright Fellowship in the interim, so I was a Fulbright Fellow at Harvard. I was working on neuroanatomy and the behavioural side of the circadian system in monkeys but also doing mathematical modelling of the human circadian system.”

Next Gander was shoulder-tapped by NASA to join their Fatigue Countermeasures Programme. In the early 1980s Congress had instructed NASA to look at the safety issue of fatigue in aviation. Circadian rhythms and their role in pilot functioning were to be key. “And that was fun, that was just amazing.” Gander became involved in a series of big field studies “which will probably never be repeated”. Hundreds of pilots were enlisted. They wore physiological monitors 24 hours a day: their heart rates were monitored continuously; they wore rectal probes to measure body temperature, and watches that monitored body movement to see when and how they slept; they maintained log books into which they self-rated their moods and fatigue every two hours. “It was very intensive stuff,” says Gander.

Here then is a sleep primer: some of the things that you, as someone who spends a third of their life in the activity, owe it to yourself to know. There are two kinds of sleep, rapid eye movement and non-rapid eye movement sleep. The two types cycle throughout your night’s sleep. REM sleep is accompanied by fast brain activity, eye movements and a lack of muscle activities. If you are woken from REM sleep you will very likely remember dreaming. If you are woken from a deep non-REM sleep you may find yourself disoriented and groggy.

Sleep is necessary. Try to fight it off for long enough and the body will eventually have its way and you will fall asleep uncontrollably. When you find it easiest to sleep, and the type of sleep you will have, is dictated by your circadian clock. You are likely to be sleepiest at around 3:00 to 5:00 am and then again at around mid-afternoon.

The circadian clock also affects other things. If you want to play chess, do it around noon. This is when your ability to solve complex problems or conduct logical reasoning is best. Play that game of badminton in the early evening when your physical coordination is best. Your short term memory is best in the morning; long-term in the afternoon.

Resetting the circadian clock is not – as any jetlagged-and-sleepless traveller will tell you – a matter of waiting for the time pips and pressing a button. The circadian clock is reset via a complex set of cues, including sunlight, work, rest and social contact. Due to conflicting cues, night shift workers hardly ever completely adapt their circadian clocks.

If you have accumulated a sleep debt over a series of nights, you will usually need two nights of unrestricted sleep to return to normal. In the mid 1990s, having worked off and on for NASA throughout the 1980s, with time out to live in France and have two children, Gander decided to return to New Zealand.

When she began her career back in the 1970s the cells in the human brain which control the circadian clock had only just been discovered. Now sleep was becoming well understood and from the early 1990s NASA’s attention had increasingly turned to putting what had been learned into good practice and public education programmes.

Gander founded the Sleep/Wake Centre in 1998 as part of the Wellington School of Medicine. She knew the relocation meant trade-offs: research budgets she would never see the like of again, against lifestyle and New Zealand’s attributes such as “a nice little laboratory”.

For with just four million people New Zealand has its advantages. Here it is feasible to do random surveys of the entire population in a way that would never be possible in the US. In the recent survey canvassing 10,000 people, the Sleep/Wake Centre and the Eru Pomare Mäori Health Research Centre had more than 7000 responses, “which is fabulous,” says Gander. “New Zealanders are interested in sleep. It really is great to be working in this country and to be working on sleep.”

The Sleep/Wake Centre is unusual in oversampling the Mäori population so that the sample sizes of Mäori and non-Mäori are the same. This allows statistically meaningful comparisons to be made between the two populations and, together with the use of an index of deprivation – a map of New Zealand broken into small units (around 90 people) rated in terms of domains of relative deprivation derived from census data – has allowed the Centre to look simultaneously at the effects of social and economic deprivation and ethnicity on the prevalence of sleep disorders.

New Zealand, which has a tradition of being something of a social laboratory for the world, is also somewhere the Centre’s scientific findings can be put into practice. “On our legislative and regulatory fronts people are experimenting with schemes that haven’t been tried in other countries,” explains Gander.

“ In transportation and aviation we have been moving away from the idea of prescriptive rules,” says Gander. “Instead there is greater emphasis being placed on fatigue management.” Fatigue is a major public safety issue. The Chernobyl meltdown, the Three Mile Island incident, the Bhopal cyanide gas catastrophe, the Exxon Valdez oil spill: lack of sleep has been implicated in them all.

Remember the 37 percent of New Zealanders who report rarely or never getting enough sleep? Another revealing percentage: there is a 33 percent increased likelihood that someone in that 37 percent has had a vehicle accident in the last three years.

Naturally, among the groups of shiftworkers that have drawn the attention of the Centre’s research are those whose roles have wider public safety implications. The Centre and its postgraduate students have looked at the effect of short naps on the functioning of air traffic controllers (they proved an effective way of improving functioning) and at the sleep-wake patterns and functioning of anaesthetists. A nationwide survey of hours of work for junior doctors is in the offing. “We’ve just had funding from the Health Research Council – the first big grant we will work on with Massey,” says Gander.

And on the roads? Although sleepiness is highly likely to be a contributing cause in many road accidents, pinning the blame is difficult. “If you are looking for whether fatigue or sleepiness was involved in an accident, it’s very hard to tell,” says Gander.

Unlike for alcohol, there is no blow-in-the-bag test for fatigue and sleep deprivation. “ You really have to reconstruct the person’s sleep history and the time of day and various other things to construct the case whether or not their function was impaired.” Usually, says Gander, the role of fatigue is recognised only by default. “People can be extremely activated after an accident or else they are injured, so how can you tell if they were fatigued]? So often it is by a process of elimination. There was no other vehicle involved, there was no vehicle fault, no alcohol, someone drove off the road or into a bridge, then you assume they weren’t controlling the vehicle and they might have been asleep. “ We are trying to move beyond this.”

For over a year Commercial Vehicle Investigation Unit police officers have been giving drivers involved in truck crashes a questionnaire about their sleep. “ That comes back to us and we then match that up with the crash report from the LTSA database to see what percentage of the crashes we think involve fatigue.” Fatigue management research and education contracts have come to the Centre from the likes of BP, Boeing and Tranz Rail.

If sleeplessness is a national affliction, then what is being done about sleep disorders? According to Gander and most sleep experts, not nearly enough. Often sleep disorders go undiagnosed. When they are spotted the treatment is often a GP’s prescription for sleeping pills, and there are too few treatment facilities. Gander argues that our treatment of sleep disorders should be more systematic, as it is in countries like America and Japan, where the prevalence of sleep disorders is similar to our own. (One of the Centre’s current PhD students has taken as her topic a systematic approach to the recognition, diagnosis and treatment of sleep disorders in New Zealand.) The Centre is working with the Eru Pomare Mäori Health Research Centre and the WellSleep Clinic to investigate the causes, prevalence and treatment of sleep disorders in New Zealand.

Sleep apnoea, a condition in which people stop breathing when they fall asleep and must wake to breathe, has come in for particular attention. Particularly common among Mäori, the condition is associated with high blood pressure, heart disease and stroke. Often the sufferers are oblivious to their condition, even though they will have experienced fragmented sleep and daytime sleepiness as a result. (Usually it is their bed partners who will have noticed the symptomatic breathing pauses, snorts, snores and gasps.) The Sleep/Wake Centre is working on a questionnaire and an accompanying index that can be used by GPs to predict which patients are likely to have sleep apnoea and should be referred for treatment.

As for the open-all-hours society, Gander has mixed feelings about it. “Apart from the emergency services, the reasons for going to 24-hour service are to improve productivity and profitability. But if there is a consequence in terms of the health and well-being of the workforce, if their health fails or their marriage breaks down, then it seems to me that there is a cost being passed on to workers, their families and ultimately the community. So are we doing a cost transfer? I think there should be a debate. I am not saying that all 24-hour work is evil and dangerous. It certainly isn’t, but we need to think about the consequences.” MASSEY looks forward to reviewing Philippa Gander’s forthcoming book Sleep and the 24-Hour Society published by Open Mind Publishing, Wellington.

A timeless place
If you want to find out what a person’s natural circadian rhythm is, there is only one way: remove all outside cues.
So sunlight will never enter the three bedroom constant environment facility being built for the Sleep/Wake Centre, and the temperature and humidity will never change.
During their stay in the facility, guests will enjoy unlimited bed rest – sleeping is forbidden, sitting up is allowed – and servings of a nutritional solution at equal time intervals.
A stay will usually be either 36 or 48 hours: enough to incorporate a complete circadian clock cycle. Meanwhile such things as core body temperatures, brain patterns, and the evening rise in melatonin will be monitored continuously.
One of the first planned uses of the facility will be to investigate the genetic variability in the circadian clock and its effects on sleep timing.
“ In the last few years the clock genes have been discovered,” says Gander. “There are a few families reported whose members all have extremely early or extremely late sleep times. They seem to have mutations in specific clock genes.”
The investigation will begin with a survey that will screen for people who report extremely late and extremely early sleep times. Then, to check how these reported times correlate with their circadian clocks, some of the respondents will be asked to spend time in the controlled environment facility.
Gander hopes the survey will provide some explanation for why some people withstand the stresses of shift work better than others. It may well be that there are some people genetically better suited to particular shifts.

Teenage sleeping patterns
“The damned kid stays up all night then spends all weekend sleeping.” The imprecation, or some version of it, must often be on the lips of the parents of teenagers. Now, according to Gander, science is providing – in some cases – an excuse note.
“ There is some evidence that the circadian clock slips, or that sleep slips until a later time in the day, and it’s biological; it’s not just oppositional behaviour,” she says.
“ That delayed sleep phase is relatively common in people in their late teens and early twenties, and then it seems to rectify.”
Biology is not the sole explanation. The sleeping patterns of adolescents are a tangle of developmental, physiological, social and cultural factors, according to Gander.
And you shouldn’t entirely dismiss your unease if your child is up until the small hours night after night.
“ At the extreme end, delayed sleep becomes a recognised sleep disorder where they can’t go to sleep until two or three in the morning. If they have to get up and go to school then they end up being chronically sleep deprived,” says Gander. She then follows with a caution: “But if they truly do have delayed sleep phase and you make them go to bed at 10 o’clock and they can’t go to sleep until 1 o’clock then you can end up giving them sleep onset insomnia.”
For her Masterate in Public Health thesis, Brigid Wilson has devised a questionnaire to untangle the factors that influence the sleeping patterns of New Zealand teenagers. The pupils of Wellington High School were enlisted to help. A repurposed US questionnaire would not do. “Apart from the language sounding totally wacky, it doesn’t address the issues in their environment,” says Gander.
One issue that has eluded US surveys is the use of energy drinks. “Yet here they are one of the most important coping mechanisms for the older teenagers.”
The questionnaire looks at cultural, biological and belief issues, matters that may one day find themselves in a sleep module in the science or health curriculum.
In preparation for the survey’s national use, a test run at Wellington High has already produced some interesting results. These show that as the students get older the gap between the time they spend sleeping during the week and on weekends grows and the sleep timing gets later. They also show that the students who lose sleep on school nights are more likely to have their own bedroom and more likely to have a TV, computer or games console there. “So there might be quite practical measures to deal with lack of sleep,” observes Gander.
Developmental changes are going on in sleep across puberty and there is evidence from the US that kids who are chronically sleepy are more likely to be involved in drugs and alcohol and probably road accidents.
And what should parents do about those slothful weekends? “Letting them sleep in on weekends is very important. If they don’t catch up on weekends, then when will they catch up?”

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