Microcirculation and the 2012 UK-US international Conference

@HealthMed The MicroCirc2012 conference at Keble College Oxford, 4-6 July, was co-organized by the British Microcirculation Society and the US Microcirculatory Society. 

Why study the microcirculation? The microvessels - small arteries, capillaries and small venules - play a vital role in providing nutrition to and removing waste products from vital organs. Microvessels are also critical for healthy maintenance of blood pressure. 

D Singer and PhD student H Saedon at MicroCirc2012

And in a wide range of diseases, a spectrum of inflammatory factors, acting on and/or derived from the microcirculation, contribute to disease causation and severity, and provide both biomarkers and targets for prevention and treatment of serious diseases from cardiovascular syndromes to diabetes, inflammatory disease and cancer, and from early abnormalities in the fetal circulation to diseases of ageing. 

A series of delegates posts are now appearing from the MicroCirc2012 conference, from a wide range of specialists, from molecular biologists to imagers, and from 1st year PhD students to senior academics. 

See more about the microcirculation and the 2012 Conference in reflections of principal organizer Professor Chris Garland, posts from delegates and in video interviews with Professor Giovanni Mann from King's College London, and Professor Steven Segal from Columbus, Missouri, USA.

Cancer risk, premature death and sleeping tablets?

@HealthMed A team of researchers from Scripps Institute and the Jackson Hole Center for Preventive Medicine in Jackson, Wyoming, in the United States has reported in a publication in the British Medical Open Journal that use of sleeping tablets is associated with increased risk of cancer (lymphoma or cancer of the lung, colon or prostate), and  premature death. Results were obtained by interrogating electronic case records within a large US health care service: the Geisinger Health System (GHS), the largest rural integrated health system in the USA. GHS serves a 41 county area of Pennsylvania with approximately 2.5 million people.
This report has been disseminated widely in the international media, including for example in the Los Angeles Times.
The 2 major questions raised by this work are whether findings are explained by effects caused by the sleeping tablets -  or are the kind of people who are prescribed hypnotics just more likely to develop cancer or premature death, as a result, for example, of genetic factors, lifestyle reasons or associated disease causing the sleep disturbance.
Obvious more specific questions include are whether this relationship is:
- caused by the sleeping tablets (hypnotics);
- a feature of 'reverse causation - ie resulting from the initial sleep disturbance having been caused by symptoms of at that stage undiagnosed cancer, or sleep disturbance caused by cancer risk factors such as smoking, excess alcohol or obesity - ie some cancer-related factor leading to patients seeking a prescription for hyponotics
- coincidental
- or spurious - the result of some bias in subject selection.
The short, ~2.5 year average treatment duration makes this possible early cancer effect important to exclude as an explanation.
The authors say they have made reasonable efforts to exclude other causes of increased cancer risk. A wide range of hypnotics were included in the study, making it unlikely that a direct chemical action of the tablets is responsible for the cancer risk.
An intriguing possibility is that the association is a marker of chemical changes in the brain arising from sleep disturbance: it is well recognized that disordered brain function leads to production by the brain of inflammatory mediators (cytokines). One consequence is the thought to be the increased risk of heart disease reported in patients who have depression. That has lead to interest in using new biological agents to inhibit the action of these cytokines as a new approach to treatment depression and other serious neurological disorders. Taking sleeping tablets, although prolonging sleep duration, may not be sufficient to induce a normal sleep pattern.
In the context of the Scripps study, this raises the question whether  inflammatory mediators
could modulate tumour formation or accelerate the growth of early stage cancers. This concept was discussed by Reiche and colleagues in a Lancet Oncology review in 2004. As an example, the chemical - tumour necrosis factor alpha - is a potent cytokine implicated in depression and - as the name indicates - with a role in tumour biology, for example in modulating tumour blood supply.
Although in the Scripps study the reported relative risk of cancer increased from 3.5 to 5-fold with the numbers of sleeping tablets used, there needs to be a clear description of absolute events rates. And the increase in premature death was from a very wide range for causes, from accidents to asthma, flu and diabetes.
Of note, this was an observational study controlled by the authors by aiming to find well-matched subjects not on sleeping tablets (cases: 10 529 patients who received hypnotic prescriptions;  23 676 matched controls). A randomised controlled trial aimed at assessing these particular outcomes would have been needed to test these findings with more confidence of lack of bias. 
If the relationship is confirmed as having a causative link, the study would illustrate yet again the importance of balancing benefit and risk when prescribing tablets, and ensuring that any prescription is  continued for the minimum clinically indicated time.

A good time to get weight in trim

New Year is a familiar time for people to make resolutions and aims to improve lifestyle.

Why bother about overweight?
Excess weight increases the burden of cardiovascular risk (high blood pressure, raised cholesterol and diabetes mellitus); causes premature ageing of arteries, leading to heart attacks, strokes and other serious disorders of the heart, brain and circulation; contributes to risk of sleep dusturbance and sleep apnoea syndrome; causes premature joint ageing with arthritis; non-alcholic fatty liver disease is the commonest cause worldwide of liver damage; and increased risk of cancers - weight gain and overweight estimated to be linked to 1 in 5 cancers.
People who have no difficulty in maintaining normal weight may find it difficult to understand the challenges. For those who are currently overweight, the challenges in regaining a more healthy weight include beating the psychological, physical and social addiction to causes of overweight, and resisting peer pressure.

Getting started
Importants steps on the path to reducing excess weight include being ready to think about action, to think about taking action and to prepare to take action. That might mean telling friends and family you are serious about losing weight, and to seek whatever help may work - e.g.  family doctor or nurse or other health professional, and support groups for the overweight.

What works? 
Smaller portion size, cutting down on processed foods and increasing exercise are the big 3 factors that help. Keep a weight chart and if possible find a friend with whom to lose overweight. Wear a belt. Pace your eating and drink water with your food. Eat regular small meals. Avoid snacking, Research evidence suggests that successful measures include recording weight regularly, knowing the approximate energy intake of what you eat, and regular activity.
It is also clear that insight into the personal health risks of overweight provide extra incentive to lose weight. Better of course to reduce excess weight before serious clinical effects of overweight occur.
There are many support groups and diet plans available to order, often at high cost.

Research evidence suggests that success in maintaining weight loss is associated with clear strategies for coping with life stresses and with 'continued adherence to diet and exercise strategies, low levels of depression and disinhibition, and medical triggers for weight loss'. In contrast, unsuccessful weight maintainers are erratic or inconsistent in recording their weight and being vigilant in keeping to healthy types and amounts of food and in continuing regular activity.
Once overweight people have maintained a weight loss for 2-5 years, the chances of longer-term success in maintaining a healthy weight are much greater.
 
Apps
 There an increasing variety of 'apps' for smartphones and PCs, that reinforce the combined impact of healthier dietary intake and maximising exercise. Many are free, with myfitnesspal an excellent example. These and other free lifestyle apps are like your personal health bank. The more active you are, the more energy balance you have towards losing weight, the more you eat, the less reserves in your health bank.

© DRJ Singer
@HealthMed 

Why have a National Blood Pressure Week?

 In the UK, over 1,500 venues are offering free blood pressure checks during National Blood Pressure Week (12-18 September 2011). Why all that effort?   High blood pressure is a major preventable and treatable risk factor for serious heart diseases and stroke syndromes throughout the world. And even at the age of 20 around one in 20 people may already have high blood pressure, increasing to around 1 in 2 people by the age of 70.

An annual blood pressure week provides an important focus to remind the public and health professionals about risks of high blood pressure, how to prevent it, measure it accurately and use lifestyle and drugs in people in whom blood pressure is too high.

Blood pressure should be as low as possible, with, for adults, the upper level, when the heart has contracted, below 140mmHg and the lower level below 90mmHg, when the heart is relaxed between heartbeats. These thresholds should be much lower in people at increased risk of blood pressure complications, such as diabetics and people with kidney disease.

Provided people are otherwise healthy, the ideal blood pressure is now considered by international experts for the upper value to below 120, the lower below 80, recorded as ‘below 120/80mmHg’.

It is very important that patients help by following a healthy lifestyle. This is both helpful to prevent high blood pressure, and for patients with hypertension, to reduce its severity. People should aim for a healthy weight, using fresh foods as far as possible, keep salt intake low, and alcohol intake within healthy limits, be active and have regular good sleep.

This year it is timely the UK’s National Blood Pressure Week comes just after the launch of important new blood pressure guidelines prepared by the National Institute for Health and Clinical Excellence (NICE) advised by experts from the British Hypertension Society (BHS).

The NICE guidelines contain new advice on blood pressure measurement, including involvement of patients in their own management, supported by home blood pressure readings.

It is of course very important that any blood pressure monitor, whether for clinical or home use, should be accurate. A helpful list of accurate devices is on the British Hypertension Society's website.’

If you have high blood pressure, you should make sure that your doctor knows about any over the counter tablets or herbal remedies you are taking, as these can interfere with the actions of blood pressure tablets.

There are now seven major types of blood pressure treatments. For best blood pressure control, prescribers need to the right drug options for the right kind of patient, taking into account, for example, age, ethnicity and potential risks in pregnancy. If single drugs are not sufficient to control blood pressure, the NICE guidelines provide advice on which drug combinations are best to use.

Useful websites:
British Hypertension Society – includes information on which blood pressure monitors are accurate  http://www.bhsoc.org
Blood Pressure Association – includes a list of venues for free blood pressure checks http://www.bpassoc.org.uk/
NICE guidance on hypertension for patients and carers: http://guidance.nice.org.uk/CG127/PublicInfo/pdf/English

New ideas on diet and cardiovascular health?

What foods may actively help to promote the health of the heart, brain and circulation? And for people who have cardiovascular risk factors, heart disease or stroke syndromes, are there dietary factors that can reduce disease severity or prevent recurrent disease?

To address these and related questions outlined below, the CVRT organised an afternoon symposium on the 'Cardiovascular effects of ‘Healthy’ foods in London on Thursday 8th December, at the Medical Society of London rooms - 11 Chandos Street - 5 minutes walk from Oxford Circus. The symposium considered evidence and mechanisms for cardiovascular benefits (or not) of ‘healthy’ foods. A key message from KT Khaw was that healthy lifestyle actions are cumulative in protecting against serious disorders of the heart and circulation.

See weblink for the programme.

Too many calories, and high intake of saturated and transfats, are well recognised to increase risk of obesity, diabetes mellitus and accelerated vascular disease (atheroma) and low salt (sodium chloride) and potassium rich foods to confer cardiovascular protection.

Outstanding questions include whether particular types of macro-nutrient (protein, carbohydrate and fats) or micronutrients (vitamins, flavenoids, trace minerals) are protective. An association between dietary factor(s) and apparent cardiovascular benefit may be causative, due to 'reverse causation' [e.g. because healthier people believe in the link or are more likely to be able to afford particular dietary constituents]; or may be a coincidental association.

Speakers at the Symposium included Professor Roger Corder from the William Harvey Institute in London, Professor KT Khaw from the University of Cambridge and Associate Professor Naila Rabbani from the University of Warwick. KT Khaw  discussed current controversies, Naila Rabbani  bioactives in fruit and vegetables, and Roger Corder dietary polyphenols and potential vascular benefits of red wine and chocolate. And Jinit Masania outlined a new EU research programme, applying nutrigenomics to assess health claims made for foods.

This Symposium followed the July 2011 event on Exercise and Cardiovascular Health, also organized by the Cardiovascular Research Trust.

Further Symposia planned by the Cardiovascular Research Trust:
- 2nd Symposia on Cardiovascular Health, Diet and Exercise: Thursday 6th December 2012 

- 3rd Symposia on Cardiovascular Health, Diet and Exercise: Thursday 5th December 2013 

 

See blog on the French healthy heart 'paradox' 20 years on.

See also Dr Carolyn Staton’s excellent blog on 'Food and microcirculation' on the British Microcirculation Society site. 


© DRJ Singer