Concerning the figures for occupation of the Icelandic men, I should perhaps add that the researchers classified about 20% of the 1297 men as manual labourers (labourers, seamen, farmers) or having a learned trade (carpenters, blacksmiths, masons), and about 11% as having an occupation requiring a university degree; the remaining 70% had other occupations. The probability of the variation in Dupuytren's incidence among the labourers and craftsmen happening by chance (after allowing for smoking and age) was calculated as 1 in 100; the probability of the variation happening by chance among the degree-holding men was greater (since the numbers were smaller) and was calculated as 1 in 5.5.

Andrew,

The Reyjavik study is in some respects contradicted by the Uppsala study (see link below). For example, the Reykjavik study concludes that someone who develops Dup's before age 50 has a near-doubled chance of dying from cancer, even when controlling for factors like smoking and diabetes;
while the Uppsala study shows a much smaller increase in cancer mortality, most of which is accounted for by controllable lifestyle factors.

So who knows? The Uppsala study had a much larger sample size, so I guess at this point it has to be given the greater weight. But even within the Uppsala study, the results seem (to this layman, anyway) to be sometimes contradictory, or at least confusing.

In general, trying to get to the truth with these epidemiological studies can be incredibly maddening. My sister once told that she had heard that regular aspirin use was linked to an increase in the risk of pancreatic cancer. So I went to the internet, found one study by reputable researchers that showed there was indeed an increase, another equally reputable study that showed there was actually a decrease, and a third that showed that aspirin had no effect one way or the other. So, let's face it, there's a lot of guesswork in health matters.

http://www.diva-portal.org/diva/getDocument?urn_nbn_se_uu_diva-1794-1__fulltext.pdf

"... a near-doubled risk of dying from cancer for people who contract Dup's before the age of 60.."

Agreed that these statistical studies often seem have little value and the conclusions unravel pretty easily. People with Dupuytren's are more likely to die from cancer - is that because Dupuytren's protects them from heart disease? I'm joking of course but, bottom line is that your chance of dying is 100% from one cause or another. Do people with Dupuytren's actually have shorter lifespans?

Andrew,

You're right, I got a little off your point regarding alcohol. Yes, it is plausible (but not proven) that the bursting of blood vessels caused by alcohol abuse can hasten the onset of Dup's. This is one of the points made by the study I quoted in my post of 5/22/05. And of course I agree that Dup's sufferers should be careful to keep healthy habits, but so should everyone.

But it is true that these epidemilogical studies cannot be taken unreservedly as the God's truth. In this week's (Sept. 3-9, 2005) issue of 'The Economist', in the Science and Technology section, there's an article about this very matter. It turns out that an amazingly high proportion (more than half) of medical research papers prove to be wrong in the long run. Truth is usually established only after long Darwinian process of claim, counter-claim and refutation.

However, to Jim H. I must regretfully say that the evidence is overwhelming that people with Dup's do have shorter lifespans. But it isn't clear whether this because of Dup's per se, or because people with other bad conditions tend to get Dup's at a higher rate. Reykjavik concludes the former, Uppsala seems to conclude the latter - although Uppsala isn't written very clearly.

So maybe conflicting studies are an excuse for inactivity - or at, for not worrying.

Regards, MML

the connection between Diabetes and DD is all over the internet on various medical sites. I suggest you make copies of these reference pages. I saw Dr Lermusiaux recently and one of his first questions was I diabetic?