Winter-meeting in Oslo

The Norwegian Hypertension Society held its bi-annual scientific meeting in Oslo last week. It was a long time in planning. We set the place and date about two years ago. Sent the first announcement in the spring of 2012 and the call for abstracts in September. Then, at the very deadline, the abstracts and registrations start to trickle in. As with all meetings, we pushed the submission-deadline back a week just to allow people without basic planning skills with pressed schedules to join the meeting and present their data. Then, in as little time as possible, all the abstracts have to be formatted into a program, and session-chairs has to be found and matched so that they have an interest but aren't speaking themselves.

Anyway, we got some 17 free communications, varying from experimental physiology to international research politics, but with a heavy focus on epidemiology and clinical research. There were a couple of talks on the recently very hot topic of renal sympathetic denervation for treatment-resistant hypertension (more on that in another post), some interesting sub-group analyses from the LIFE and SCAST studies, and follow-ups on the now 40-year-old Oslo-Ischemia-Study. More of the program at the society home-page.

In addition, we had two invited lectures on statistics in clinical research. The first on how to develop and validate prognostic models by Ingar Holme, and the second on over-adjustment bias in multiple regression models held by Knut Liestøl. It was a useful repetition of the uses and pitfalls of these two very similar kinds of models that require very different study-designs and give very different information in the end. A common problem is that one tries to get etiological information from prognostic research, i.e. treating a risk-factor as a cause for the chosen end-point even though the observational design makes that impossible. The converse is equally common, i.e. trying to infer prognostic information from etiological studies, such as clinical trials, where the highly selected population makes general conclusions very suspect.

All told, it was a very successful meeting, well worth the time both for planning it, and attending.

Prevalence of hypertension in Norway

The Norwegian society for hypertension got a surprisingly difficult question: What is the prevalence of hypertension per age group in Norway?

You would certainly think there was a straight forward answer to that question, and that we should know it. You don't even predict the question, because you think it has to be published in an easily accessible form. Any way, it is not. The best current evidence is only published in Norwegian, so in the interest of the hypertension community here is the short story.

2000-2003 the Norwegian institue of public health performed a health survey in selected counties and this was published in the journal of the norwegian medical association(Pubmed: Tidsskr Nor Laegeforen. 2007 Oct 4;127(19):2537-41.). The data is in table 4. What it says is that 17.4 % of men and 3.2 % of women aged 30 had a systolic blood pressure higher than 140 mmHg and/or a diastolic blood pressure higher than 90 mmHg. The number of hypertensives gradually increased to 65.4 % of men and 69% of women at the age of 75 years.

Thanks to my collegues in the Hypertension society for helping me find the data. Especially Randi Selmer at the Norwegian institute of public health who provided (and co-authored) the paper.

In the coming year we can look forward to the publication of the whole population data from the health survey in the county Nord-Trøndelag study number 3 (HUNT-3). There still will not be a definitive answer to the question of the prevalence of hypertension in Norway, but age group coverage will be down to 13 years of age.

So, as far as I can see, I have a 82.6 % chance of not having hypertension (not counting that I am rather stressed at the moment, which would bring it down to -10% somewhere).

/Michael