Cardiovascular diseases and the search for more evidence
Daniel Day Lewis won an Oscar this year for his depiction of Abraham Lincoln’s role in the abolition of slavery in the USA. As I watched Lincoln on the plane crossing the Atlantic, I wondered how many inequalities still exist in health and whether laws are the best way to reduce or abolish these inequalities.
Looking at just cardiovascular diseases, inequalities have been highlighted at local, regional, national and international levels, whether on the basis of gender, age, socioeconomic status or race. We have known about the major risk factors which cause cardiovascular disease for over 50 years, and yet some of these inequalities still pose significant challenges in many parts of the globe. An example from the UK is the recent study showing regional variations in mortality from cardiovascular disease in each electoral ward.
So do we not have enough evidence to act? Do we need to keep producing more research to show that inequalities and variations still exist? Of course, the answer is that we need to keep producing evidence, not just to understand the causes, “the causes of the causes” and in order to plan the best strategies to tackle these inequalities. Moreover, the evidence needs to be presented in new ways to reach the hearts and minds of policymakers in order to enact change.
In Circulation this week, Ezatti and colleagues consider the effect of macroeconomic changes on cardiovascular risk factors over time at the global level for hypertension, diabetes, hypercholesterolaemia and obesity. At the country level, systolic blood pressure, total cholesterol and body-mass index were positively associated with gross domestic product (GDP) and Western diet in 1980, whereas only total cholesterol remained positively associated with GDP in 2008. In an accompanying editorial, I make the point that existing surveillance systems for cardiovascular disease and its risk factors at global level are inadequate. This week, I am at the American Heart Association Cardiovascular Epidemiology and Prevention Meeting in New Orleans, learning about new data and new ways of presenting the data regarding cardiovascular diseases. Relating changes in cardiovascular disease to economic and macroeconomic change seems a promising strategy to get the attention of policymakers.
All Trials Registered | All Results Reported
“Thousands of clinical trials have not reported their results; some have not even been registered.” All trials registered | All results reported
This is a problem.
A petition was launched today that calls on governments, regulators, and research bodies to put measures in place to register and report the methods and results of clinical trials. This initiative, led by Bad Science, Sense About Science, BMJ, James Lind Initiative and CEBM is important. This issue effects all of us: patients, researchers, clinicians, politicians, scientists, and industry.
The petition was followed with a rip roaring editorial by Iain Chalmers, Paul Glasziou and Fiona Godlee in the BMJ that calls for all trials to be registered and their results published. This excellent piece details the consequences of our collective abstention from action and provides advice to patients whom are invited to participate in clinical trials; name:
“Agree to participate in a clinical trial only if: (1) the study protocol has been registered and made publicly available; (2) the protocol refers to systematic reviews of existing evidence showing that the trial is justified; and (3) you receive a written assurance that the full study results will be published and sent to all participants who indicate that they wish to receive them.”
Don’t wait, sign the petition now.
After signing you can automatically share the message “I've just signed the #AllTrials petition for all trials registered and all results reported” on Twitter or Facebook.
Be proud you are taking a step for transparency and improving patient care. I know I am.
Are you sitting comfortably?
For those interested in the history of medicine you may have heard of Jeremy Morris (1910-2009). Dr Morris was a Scottish epidemiologist who, during the 1950s, was involved in establishing the link between a lack of physical activity and increased cardiovascular risk. In his paper, published in The Lancet, Dr Morris and his colleagues teamed up with London Transport, The Post Office and The Treasury Medical Service. The London Transport Workers Study observed 31,000 men aged 35-64 employed as bus drivers and conductors. They found that you were more likely to suffer from coronary heart disease as a sedentary driver, than as a conductor who climbed the stairs of a double decker bus. This finding also reflected their data in postal workers who were less likely to suffer with coronary heart disease that desk based civil servants. Although a number of limitations of their work were acknowledged, it was clear that a link had been made and in 1996 these contributions were recognized when he was awarded the first International Olympic Committee Prize for Sport Sciences.
Over 60 years later the data linking physical inactivity with ill health continues. Last week researchers at The University of Leicester published a paper on the association between sedentary time in adults and the risk of diabetes, cardiovascular disease and death. They collected data from 18 individual studies. For each one they calculated the risk of ill health associated with the highest sedentary time versus the risk with the lowest, a relative risk (RR). They found a 112% increase in the relative risk of diabetes, a 147% increase in cardiovascular events and a 90% increase in the risk of cardiovascular mortality. With figures like that it’s no wonder the results made the widespread public media. Of the 18 included studies the authors used for their analysis, 13 used TV viewing as their sedentary measure, which was interesting as the authors also stated in their introduction that TV viewing may not be a good representation of total sedentary time, perhaps suggesting it could be an over- or under- estimate. The other 5 studies used self-reporting of sedentary time which is notorious for having poor reliability. That said if someone asked you how much time you sit down in a day, do you think you were more likely to over or under estimate? The other interesting point was that the risk seemed independent upon how much activity you were doing outside the sedentary time. So even if you go to the gym for 1 hour, it’s what you do with the other 23 hours that seem to count as well.
Despite some limitations, the paper adds to the work of Dr Morris and others, supporting the evidence linking physical inactivity and ill health.
Crikey!...even now you might be sitting down and reading this. I better add some handy tips for standing up while sitting.
As for me, I’ve been sitting down and writing this for 40 minutes, time for a stretch I think…