Health Newsletter:October 2003
Related Links:| Heart Scan Diabetes Heart Attacks | Flu Vaccine Influenza Respiratory Infections | CT Scans Stroke Recovery Blood Pressure | Schizophrenia Antidepressants Psychiatric Help | Asthma Allergies Respiratory Infectios |
From WebHealth
Contents |
Heart Scan Saves Lives In Diabetics
A simple new nuclear perfusion study of the heart when applied to healthy appearing diabetics (adult onset or "type 2 diabetics") showed silent hardening of the coronary arteries in 21.6%. This large study of an American medical team was recently presented at the 18th Congress of the International Diabetes Federation in Paris/France. Dr. F. Wackers, professor of medicine from Yale University school of medicine and one of the lead investigators, explained that 1,124 patients with diabetes in the age range of 55 to 75 years who were all thought to not have any heart blood vessel disease, either had nuclear perfusion studies performed and a control group did not.
As indicated above to the surprise of the investigators 113 patients of 522 (=21.6%) had positive heart scans showing perfusion difficulties of the heart muscle. Further testing with other methods revealed that 73% indeed had perfusion defects and 27% had other heart disease, electrocardiogram abnormalities and other heart dysfunctions. Conventional assessment tools such as a smoking history, determination of degree of obesity, blood pressure,kidney disease , high blood lipid levels, high C-reactive protein levels, the diabetes test hemoglobin A1C or homocysteine levels in the blood were also assessed. However, these conventional tests did not help in predicting that these patients would have developed perfusion defects in their heart muscle. This was due to hidden narrowing of the heart blood vessels (=coronary arteries) and this affected the supply of nutrients and oxygen to the heart even though these patients were completely symptom free at the beginning of the trial.
Dr. Vivian Fonsega, a professor of medicine and pharmacology at Tulane University in New Orleans and co-researcher of the team, added that after a follow-up of 1 year those who had normal initial nuclear perfusion studies of the heart only 1% developed serious heart disease. These control patients who have now been followed for 3 years overall remained very healthy. In other words a normal (called "negative") nuclear perfusion test in diabetics predicts a better longterm outcome than a positive perfusion test.
With this heart scan the cardiologist can identfy the high risk group among diabetics and can subsequently concetrate on doing something actively about the identified diseased heart blood vessel(="coronary artery") disease. Identified narrowing in the coronary arteries ("stenotic arterial lesions") can be overcome by prying them open and placing heart stents across the affected section utilizing catheters (angiography). In other cases heart bypass surgery can be done by the heart surgeon to improve the perfusion of the heart muscle. The researchers stressed that those diabetics at risk can be identified with this test and the life expectancy of this high risk group of patients can be significantly prolonged. The study will continue for several more years so that the longterm results of any intervention can be measured when compared to controls.
Here is a link to a chapter on diabetes and here is a link to heart attacks.
Based on The Medical Post (Sept. 23, 2003 ): p. 55.
Flu Shot Cuts Death Rate Into Half
An earlier publication in the New England Journal of Medicine in March 2003 has shown that the death rate of people 65 years or older who were vaccinated against the flu, dropped into half when they were exposed to the flu and were compared to non-vaccinated controls. On Oct. 9, 2003 Dr. Megan Wren, associate director of the internal medicine residency at Barnes-Jewish Hospital and Washington University School of Medicine, reminded physicians that with the upcoming flu season it is important to include everybody who is healthy at age 50 or older (as the CDC has suggested now for 3 years) with influenza vaccination . Many physicians are still not aware that the rules have been changed to incude younger persons.
Here are recommendations of who should get a vaccination in table form.
| Who should get the flu vaccine | |
| Group of people: | Comments: |
| all people age 50 or over | the
immune system weakens with age, that's why complications of the flu are more common in this age group |
| women
who will be in the 2nd or 3rd trimester of a pregnancy during November through to March |
protects
the fetus from the flu virus in the most vulnerable period of the development of the fetus |
| chronic heart disease or lung disease (including asthma) | the flu affects the lungs and the heart most readily |
| chronic kidney or liver disease | these chronic diseases weaken the immune system |
| people without a spleen and cancer patients | the immune system is weak in these patients |
| children and adults with any chronic disease including diabetes | chronic illnesses weaken the immune system in young and old |
| people on imunosuppressive medications | the immune system is weak in these patients |
| all close family members of any of the above people | the
CDC hopes that this stops the spread of the flu into this vulnerable group of patients |
Dr. Wren pointed out that the risk from a flu vaccination is minimal. Contrary to public belief the flu vaccine does not cause fever, unwellness or muscle aches. The only effect is a mildly sore arm at the site of injection.
This year the FDA has approved a live flu vaccine that is administered as a nasal spray. This is a live modified flu virus that has been "trained" to only multiply in the colder nasal cavity, but not in the warmer airways. Like with all live viral vaccines pregnant women are not allowed to take this. Dr. Wren also mentioned that people with chronic illnesses, with immune deficiencies (e.g. AIDS and cancer patients) and healthy patients over the age of 50 cannot take this live vaccine. All others from age 5 to 49 can take it, but presently this is still very costly (one nasal mist application in 2003 is about 50.00$ US).
Better Recovery From Strokes Through Early CAT Scans
In the September 2001 issue of the American Journal of Neuroradiology (Am J Neuroradiol - 01-SEP-2001; 22(8): 1534-42) a group of clinicians from the Foothills Hospital in Calgary/Alberta had published an article with a scoring system for CAT scans (also abbreviated CT scans) that would be done on every patient with a stroke. By utilizing early CT scans and this scoring system an ischemic stroke (due to a blood vessel that closed off in the brain) could be rapidly assessed. Within 3 hours of the beginning of the stroke the treating physician would know whether the patient would benefit from clot-busting drugs (tPA or tissue plasminogen activator) or not. Dr. Pexman and co-workers had noted that patients with an Alberta Stroke Program Early CT Score (ASPECTS) of less than 7 had a poor survival rate or an outcome with high dependency on caregivers. Patients with a score of 7 to 10 had a much better survival chance and were ideal candidates for the clot-busting therapy. The brain of the stroke patient depicted by CT scans using this method is divided into 10 regions and the findings are systematically evaluated by the radiologist and an ASPECTS score is obtained.
Dr. Michael Hill, an assistant professor at the University of Calgary, and one of the co-workers of this initial study has now completed a further follow-up study together with Dr. A.Buchan, director of the Calgary Stroke Program. The results were published in the August 2003 issue of the medical journal "Stroke". They found that ischemic strokes (from clots in the middle cerebral artery) have the best outcome when detected by CT scan early (within 3 hours of the beginning of the stroke) and if thrombolysis therapy with tPA, the clot-busting drug, is done before 6 hours after the beginning of the stroke. The lack of blood circulation from a stroke,which closed the middle cerebral artery, is shown in this link.
What does that mean in practical terms? Let us assume a patient is suddenly losing all of the strength and movement in one arm and losing speech as well. An emergency CT scan is done right away and it is determined that the patient has had a stroke in the middle cerebral artery. Let us say that the ASPECTS score was between 7 and 10. This patient's physicians would likely treat the stroke with the clot-busting medicine mentioned being confident that there likely will be a good outcome.
In the past, before this therapy was available, many of these patients would end up with a permanent arm palsy without much function and sustain a permanent speech deficit as well. After the clot-busting therapy many of these patients who have a good outlook will now have a considerable, if not full return of function in their arm and regain their speech as well. Unfortunately, the opposite is true as well: those with a poor ASPECTS score below 7 will not be candidates for the clot-busting therapy and will tend to do poorly.
This scoring system of early CT scans with strokes (ASPECTS) is already being used in several countries such as Canada, the US, Australia and Europe. "Early detection and intervention in stroke is critical to achieve a positive outcome" said Dr. A.Buchan, director of the Calgary Stroke Program, who is also a professor in the department of clinical neurosciences of the University of Calgary/Alberta.
Here is a link for more background on strokes.
Schizophrenia Gene Discovered
In the not too distant future new tests and new antipsychotic drugs ("designer drugs" rather than "trial and error drugs") for schizophrenia will likely be developed in the US because of the following new findings.
At the 19th International Congress of Genetics in Melbourne/Australia the Nobel Prize laureate Dr. Susumu Tonegawa, who had won the 1987 Nobel Prize for Medicine, reported about his new discovery of a gene that controls schizophrenia. This has already been studied extensively in mice by the research team that he is heading (from the Howard Hughes Medical Institute of Technology (MIT) in Cambridge/Mass).
Together with other collegues from other Centers (Duke University, Rockefeller University and Columbia University College of Physicians and Surgeons) they have developed an animal model, a "schizophrenic mouse", that is defective for the schizophrenia gene. Researchers had found that an enzyme called "calcineurin" was missing in schizophrenic families where genetic defects could be located in one particular gene. Subsequently this type of gene was also shown to be important for the normal brain metabolism in mice. The detection of a mouse model for schizophrenia has made it much easier to do ground-breaking research in the field of schizophrenia. Dr. Tonegawa said that the existing drugs for schizophrenia were developed by trial and error. In some patients these drugs do not work, in many others they have serious side-effects. He stated further that in future there will be a new class of anti-psychotic drugs with minimal side-effects as they will specifically normalize the calcineurin production. This in turn will normalize the derailed brain metabolism. In schizophrenics it is in this area where the psychotic behavior originates due to a lack of normal calcineurin production. This enzyme is found not only in brain tissue, but also in immune cells such as the T lymphocytes throughout the body. Because of this connection a future modern treatment for schizophrenia will likely normalize the brain metabolism, but also have beneficial effects on the entire immune system.
Here is a link to a review of schizophrenic disorders
Ozone And Pollution Linked To Asthma
Ozone and pollutants were the topics of two independent publications in October 2003, one in the New England Journal of Medicine (N Engl J Med) and the other in the Journal of the American Medical Association (JAMA).
Dr. Janneane F. Gent of Yale University School of Medicine in New Haven, Connecticut, and her team studied the effects of ozone and small pollutant particles on 271 cases of asthma in children less than 12 years of age (results published in the Oct. 8 ,2003 issue of JAMA). The researchers asked the question whether the air standards of the Environmental Protection Agency would be safe for asthmatic children. From spring 2001until now (about 2 years) exposure of air pollution was measured.
They found that in terms of particulate matter in the air the minimum standards were acceptable and no worsening of asthma took place because of flucutations in this component of air pollution (fine particulate matter of 2.5 micrometers or less). However, exposure to fluctuating ozone levels considered sofar to be safe were found to have profound effects in terms of worsening the asthma in the group of children being followed. For every 50 parts per billion (ppb) increase (in one hour ozone level) the wheezing of these astmatic children increased by 35% and chest tightness increased by 47%. At the time of the highest ozone exposure from a bad day of pollution, which was still "acceptable" to the standards of the Environmental Protection Agency, there was a 32% increase in shortness of breath and the children had to increase their medications by an average of 8% to cope with their asthma attacks (based on JAMA 2003;290:1859-1867,1915-1916).
A different facet of the asthma problem was dealt with in the Oct. 9, 2003 issue of the New England Journal of Medicine. Dr. Malcolm R. Sears from the McMaster University in Hamilton/Canada reported about a group of 613 children born in Dunedin/New Zealand in 1972 and 1973 who were followed with breathing tests and questionnaires until they reached the age of 26 years. This study showed that it does matter very much what lung irritants the very young asthmatic was exposed to and what lung irritants continue to affect the person later in life.
About half of the study population had at least one wheezing attack during the 26 years of observation. Contrary to popular belief asthma is not something "you grow out of" with age as 26.9% either had wheezing that persisited all the time (14.5%) or where the wheezing came back in adult life(12.4%). Allergies to house dust were associated with a risk of more than double and general airway hypersensitivity was associated with a triple risk of causing wheezing persistence or causing a return to wheezing. Other factors that were contributing to risk were female gender (1.7-fold risk) and exposure to cigarette smoke (1.8-fold risk). Those who started smoking young had the highest risk of asthma persistence and severity.
The more wheezing attacks there were and the more persistent the asthma was, the more permanently abnormal the lung function tests remained. The authors concluded that intervention against factors that lead to asthma must be initiated at a very young age. It is crucial to not allow environmental factors (ozone, pollution, allergens, cigarette smoke etc.) to interact with the asthma gene as this will lead to the more severe and chronic forms of asthma with permently abnormal lung function.
These two studies would reconfirm what the recent Swedish family lifestyle study had found as well. All of these studies point to the importance of the air quality and how the environment affects not only those with asthma, but affects everybody. Asthmatics simply are the tip of the iceberg due to a genetic weakness with which they were born. This makes asthmatics particularly vulnerable to pollution and to other environmental factors.
Link to a chapter on asthma from WebHealth.
