Tuesday, February 18, 2014
Type 2 diabetes may NOT be caused by suddenly piling on the pounds: Most patients 'have been overweight for years'
I have been challenging this supposed causal link for years
Type 2 diabetes might not be caused by piling on the pounds, new research suggests. Researchers discovered people who have been of a stable, but excessive, weight for many years are more likely to develop the condition than those who have recently gained a lot of weight.
As a result, they say the best way to reduce the number of cases of diabetes could be to focus on small weight reductions for the whole population rather than on major weight loss programmes for a few high-risk individuals.
Researchers at the Steno Diabetes Centre in Gentofte, Denmark, studied data from 6,705 participants of the Whitehall II cohort – a group of London-based civil servants who have been followed for more than 10 years. All of the volunteers were free of diabetes when the study started but after 10 years, 645 had been diagnosed with the disease.
The researchers looked back at recordings of their BMI during the 10 years of the study.
They discovered that the vast majority of those who had been diagnosed with diabetes – 606 people – had been overweight throughout the study. These people’s weight, however, had been stable.
Only 15 of the people who developed diabetes had gained weight continuously in the years before their diagnosis and just 26 were obese for the entire time they participated in the study.
The researchers admit that to confirm the findings they would have to study more diverse groups of people. However, they say their research gives an indication of how best to identify people at risk of diabetes.
The authors wrote: ‘Strategies focusing on small weight reductions for the entire population may be more beneficial than predominantly focusing on weight loss for high-risk individuals.’
The remarkable power of the placebo: Patients who had FAKE surgery for a broken back recovered just as well, documentary reveals
The power of suggestion has long been known to be enormous
We’ve all heard of placebos. They’re dummy pills. They can’t do anything real. After all, there’s nothing in them. At least, that’s what we thought.
But in recent years, evidence has built up to suggest that placebos can be highly effective – particularly in treating pain, depression, and even alleviating some of the symptoms of Parkinson’s disease.
And it isn’t just dummy pills that seem to be able to work: you could get life-changing improvements from a pretend potion that’s actually just water; or perhaps fake acupuncture with needles that don’t even puncture your skin.
The key is simply that you think it might help you.
But when it comes to placebos, it doesn’t get much more dramatic than what’s been called sham surgery – as Dr David Kallmes discovered a few years ago.
He’s a successful radiologist at the Mayo Clinic, one of the world’s leading hospitals – it’s where the Presidents of the United States often get treated.
For the past 15 years, he’s been fixing broken backs by injecting them with a special kind of medical cement.
Dr Kallmes regularly performed the procedure – called vertebroplasty – and found it hugely effective.
'We saw terrific results from the procedure, really amazing results,' he told me.
However, there were some questions as to exactly what was going on – because some people seemed to get better even when the operations went horribly wrong.
We’ve all heard of those calamitous procedures where someone has the wrong leg amputated. Well occasionally, people in need of vertebroplasty had the wrong vertebra filled with cement.
And yet it still worked.
As Dr Kallmes rather delicately puts it: 'There was some reason to suspect that there were numerous factors at play in the apparent effectiveness of the cement'.
He decided to do something very unusual – something that most doctors would be incredibly nervous about, but something that a good scientist can’t resist: he decided to conduct an experiment to see whether vertebroplasty was any more effective than a placebo.
He designed a trial in which some patients would be given genuine vertebroplasty, and some would be given a placebo.
But in this case the placebo couldn’t be a dummy pill, it would have to be a fake operation.
It was important that the 130 patients on the trial didn’t know whether they were having the real thing or the placebo.
This meant that Dr Kallmes had to develop an elaborate ruse to ensure that patients wouldn’t work out which group they were in.
All patients were prepared for their ‘operation’ in the same way; they were wheeled into theatre, and given a local anaesthetic in their back.
It was only at that stage that it was decided whether or not they’d have the placebo or the vertebroplasty, and it was a computer that randomly decided their future.
Even the doctors didn’t yet know whether they were about to perform a real procedure, or whether they’d just be pretending.
'In both cases,' says Kallmes, 'No matter how they were randomised [i.e. which operation they were having, the real or the fake], we then opened the cement, which has a very strong odour like nail polish remover, to really simulate it for everybody in the room.'
Half the patients then received the real operation; the other half experienced theatre, but not of the operating kind.
Dr Kallmes explains: 'If they were randomised to placebo, we had a script that we followed, we pressed on the back and said okay ma’am, the cement is going in now, everything’s going fine, things are going well, a few more minutes here, okay we're all done.'
It almost sounds like a child’s game of doctors and nurses.
For Bonnie Anderson, one of the patients on the trial, it would have seemed impossible that play-acting could give her the relief she needed.
After slipping in her kitchen, she’d cracked a vertebra and was in immense pain, barely able to move. 'I couldn’t stand up straight, I’d have to hold onto something. The pain was just very, very severe,' she said.
What’s more, Bonnie had actually had a real vertebroplasty the year before, when a different vertebra had fractured. She knew what to expect from the procedure. It wouldn’t be easy to fool her.
And yet for Bonnie, the effectiveness of the placebo – though she didn’t know that’s what it was – was clear. 'Within a week….I was able to play golf, I took it a little easy, but I was able to play golf almost every day.'
At 76 years old, as she was at the time of the trial, a game of golf every day suggests a fairly effective operation…
In fact, Bonnie noticed no difference in pain relief between the real thing, and the placebo.
And she wasn’t the only one for whom the pretend procedure was so effective. As Dr Kallmes sums up: 'There was no statistically significant difference in degree of pain relief between the patients who underwent vertebroplasty and placebo.
'And more importantly, there was no statistically significant difference in improvement in function between the patients who underwent vertebroplasty and placebo.'
To be clear, there’s no suggestion that the pretend operation was healing people’s broken bones.
The assumption is that it worked because it relieved patients of their pain long enough for the bone to then heal naturally.
Nonetheless, the results shocked the medical community – after all, doctors around the world had performed vertebroplasties on over a million people.
Coincidentally, at the same time as Dr Kallmes was doing his trial in the U.S., another scientist was doing a similar study in Australia. Once again, vertebroplasty failed to do better than a placebo.
Normally, if a pill or a procedure doesn’t beat a placebo, we’d assume that it doesn’t work – after all, it’s no better than a dummy pill, or a pretend procedure.
The difficulty here is that it wasn’t the case that neither vertebroplasty nor the placebo worked; rather, they both worked.
Patients who experienced vertebroplasty or the placebo both got better than if they’d had no treatment.
As Kallmes says, 'the drastic diminution in pain at 24 hours in our study suggests that the procedures had immediate benefit.
'We published the three-day outcomes, which also show marked decrease in pain.' That steep drop wouldn’t be expected if the patients had just been left to heal naturally.
The fact that a pretend procedure is considerably more useful than doing nothing at all has led to an interesting situation for Dr Kallmes and his colleagues: insurance companies are now reluctant to pay for the cost of a vertebroplasty – a few thousand dollars is a lot of money for a medical procedure that’s no more effective than something an actor could do.
And yet whether its effects are due to the cement or to the placebo effect, Dr Kallmes knows that vertebroplasty is still useful.
The fact is, there aren’t really any other options: he can’t perform the pretend procedures outside of the trial as it would be immoral to lie to patients and trick them about the treatment they’re receiving.
As Dr Kallmes acknowledges, 'We don’t have much else to offer these patients.'
And so even though he found it to be no more use than a pretend procedure, Dr Kallmes, is still performing vertebroplasties.
Amazingly, it isn’t the only surgical procedure that’s been found to be no more effective than a placebo.
A well-reviewed Finnish study recently found that one of the world’s most common orthopaedic operations – arthroscopic partial meniscectomy of the knee – is no more effective than ‘sham surgery’.
Surprising though this is, there’s certainly no suggestion that the benefits of many other surgeries might be entirely due to the placebo effect. No one would argue that a pretend operation could remove a tumour, for instance.
But doctors and scientists are starting to become more aware of the power of the placebo effect – particularly in surgery, where our hopes and expectations of a dramatic recovery are at their highest.
There’s no doubt that there’s still an enormous amount we don’t know about placebos and how they work. Why do some people respond so well, and others not at all? Do our genes play a role? What are the exact mechanisms through which placebos work?
But at least now, instead of seeing a placebo effect as a statistical tool to develop new drugs and treatments, scientists are starting to investigate how placebos work.
And the more we find out, the better our chance of harnessing their power, and making the most of our bodies’ abilities to heal themselves.
Posted by jonjayray at 12:22 AM