Tuesday, August 28, 2007


This is such fun that I am going to let it stand without comment:

Incident dementia in women is preceded by weight loss by at least a decade

D. S. Knopman et al.

Background: Although several studies reported weight loss preceding the onset of dementia, other studies suggested that obesity in midlife or even later in life may be a risk factor for dementia.

Methods: The authors used the records-linkage system of the Rochester Epidemiology Project to ascertain incident cases of dementia in Rochester, MN, for the 5-year period 1990 to 1994. The authors defined dementia using the criteria of the Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM-IV). Each case was individually matched by age (~1 year) and sex to a person drawn randomly from the same population, and free from dementia in the index year (year of onset of dementia in the matched case). Weights were abstracted from the medical records in the system.

Results: There were no differences in weight between cases and controls 21 to 30 years prior to the onset of dementia. However, women with dementia had lower weight than controls starting at 11 to 20 years prior to the index year, and the difference increased over time through the index year. We found a trend of increasing risk of dementia with decreasing weight in women both at the index year (test for linear trend; p < 0.001) and 9 to 10 years before the index year (test for linear trend; p = 0.001).

Conclusions: Even accounting for delays in diagnosis, weight loss precedes the diagnosis of dementia in women but not in men by several years. This loss may relate to predementia apathy, loss of initiative, and reduced olfactory function.

NEUROLOGY 2007;69:739-746

Crazy hours for doctors are dangerous

Although most people are aware of their impaired function after going without one or two nights of sleep, the most common form of "sleep loss" is shortening of sleep hours. Everyone encounters some nights of reduced sleep length but when this persists and there is no or little recovery sleep, problems occur. Recent research has highlighted that shortening sleep to four or even six hours per night over a two-week period is associated with increased lapses in attention due to "microsleeps". More worrying is that individuals who have restricted sleep seem to have an inability to monitor their own deterioration in performance, resulting in overconfidence in their ability to undertake tasks. So a sleep-restricted person may behave in the same way as a person who has had too much alcohol to drink, both underestimating their impairment and thinking they are fit to drive a car or some other responsible task, like complicated medical surgery.

Indeed, the hospital workplace is one setting where the risk of sleep loss has increasingly attracted attention from medical researchers. Professor Charles Czeisler and his team from Harvard University have recently published a series of landmark papers in The New England Journal of Medicine and other leading medical journals. These papers have provided direct evidence that working extended shifts in the hospital intensive care unit results in more errors, especially medication orders. Shorter split shifts with time allowed for napping resulted in fewer errors. In a nationwide US survey of 2737 interns, the Harvard group found extended shifts were linked to a greater rate of needlestick injuries and near-miss or actual driving accidents.

How does this relate to the hospital workplace in Australia? Although, in general, work-hour regimes are kinder here than in US hospitals, 15 per cent of all doctors in Australia report working more than 80 hours per week. Problems arise in rural areas or in specialised settings where individuals may be on call all week. We know that even being on call without being called in can impair sleep and often little is done to acutely monitor on-call specialist trainee work hours. These trainees are few in number and in high demand. Even more worrying is who monitors the sleep-wake schedules of their bosses. Watching a senior hospital specialist fall asleep at a lunchtime meeting often provokes a laugh but perhaps ignores the underlying problem. No patient would consent to surgery if they noticed their doctor's breath smelt of alcohol. However, how many patients ask their surgeon how much sleep they've had lately?

Hospitals are often imbued with a cultural mix of altruism, machismo and denial. Many of us who have worked in hospitals have bored our friends and family with tales of stoical never-ending shifts and battling to stay awake in a sleepy fog. The reality is that we can't kid ourselves that this is safe and any hospital administration that tolerates this situation is at fault. The current shortage of doctors in the health system has resulted in "moonlighting", with some doctors working for two or sometimes three employers. At the moment hospitals in Australia are probably more concerned where their doctors left their last SIM card but they should also be asking where else do you work, how many hours do you work and how much sleep do you get?

Health administrators may be held criminally liable for their sleepy doctors in the same way that a transport company may be held criminally liable for fall-asleep accidents caused by its drivers. The first step to prevent this is to recognise the risk, use scientifically proven strategies to deal with the problem and finally to recognise that the best treatment is to sleep like a dog.



Just some problems with the "Obesity" war:

1). It tries to impose behavior change on everybody -- when most of those targeted are not obese and hence have no reason to change their behaviour. It is a form of punishing the innocent and the guilty alike. (It is also typical of Leftist thinking: Scorning the individual and capable of dealing with large groups only).

2). The longevity research all leads to the conclusion that it is people of MIDDLING weight who live longest -- not slim people. So the "epidemic" of obesity is in fact largely an "epidemic" of living longer.

3). It is total calorie intake that makes you fat -- not where you get your calories. Policies that attack only the source of the calories (e.g. "junk food") without addressing total calorie intake are hence pissing into the wind. People involuntarily deprived of their preferred calorie intake from one source are highly likely to seek and find their calories elsewhere.

4). So-called junk food is perfectly nutritious. A big Mac meal comprises meat, bread, salad and potatoes -- which is a mainstream Western diet. If that is bad then we are all in big trouble.

5). Food warriors demonize salt and fat. But we need a daily salt intake to counter salt-loss through perspiration and the research shows that people on salt-restricted diets die SOONER. And Eskimos eat huge amounts of fat with no apparent ill-effects. And the average home-cooked roast dinner has LOTS of fat. Will we ban roast dinners?

6). The foods restricted are often no more calorific than those permitted -- such as milk and fruit-juice drinks.

7). Tendency to weight is mostly genetic and is therefore not readily susceptible to voluntary behaviour change.

8). And when are we going to ban cheese? Cheese is a concentrated calorie bomb and has lots of that wicked animal fat in it too. Wouldn't we all be better off without it? And what about butter and margarine? They are just about pure fat. Surely they should be treated as contraband in kids' lunchboxes! [/sarcasm].

Trans fats:

For one summary of the weak science behind the "trans-fat" hysteria, see here. Trans fats have only a temporary effect on blood chemistry and the evidence of lasting harm from them is dubious. By taking extreme groups in trans fats intake, some weak association with coronary heart disease has at times been shown in some sub-populations but extreme group studies are inherently at risk of confounding with other factors and are intrinsically of little interest to the average person.


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