Diabetes News for June 30, 2002
Versatile Adult Stem Cells
One of the major issues in the stem cell debate is that the cells are usually taken from embryos that are destroyed in the process of extraction. A new study may answer this problem, as it shows evidence that certain adult stem cells may be just as versatile as those derived from embryos.
Stem cells are cells that have the potential of developing into any cell in the body, giving scientists great hope that these cells can be used to cure diseases like cancer, diabetes, Parkinson's, and Alzheimer's by replacing diseased cells. Although the most flexible stem cells have been found in embryos, researchers from the University of Minnesota Stem Cell Institute have found that stem cells taken from adult bone marrow may be just as effective. The researchers were able to extract these stem cells, called multipotent adult progenitor cells (MAPCs), from adult mice. They then injected the MAPCs into early mice embryos. Later, they were able to detect evidence that these MAPCs had developed into many tissues of the mice, indicating that the original MAPCs had developed into many different kinds of cells.
The researchers have some hope that MAPCs may prove effective in treating human diseases, despite the rarity of these cells and the difficulty in extracting them from bone marrow. Much more research is needed before this subject can be studied in humans. The results of this study have been published in the online version of the June 20, 2002, issue of the journal Nature. Another article in the same issue shows encouraging results in the treatment of Parkinson's Disease with embryonic stem cells.
  
Alcohol Not Advised To Prevent Diabetes
Several studies have shown that light to moderate drinking may prevent Type 2 diabetes, but recent research does not appear to confirm this. A new study conducted by doctors at the Royal Free and University College Medical School, London, UK involved 5,221 healthy British men between the ages of 40 and 59. The men were followed for 17 years, and 198 of them developed Type 2 diabetes during the study.
Part of the study involved tracking the participants' alcohol consumption. Moderate drinkers consumed 16 to 42 drinks per week and were found to have the lowest risk of developing Type 2 diabetes. The participants who drank more than 42 drinks per week had the highest risk of developing the disease, probably due to the men's excess calories and weight.
However, the researchers, who published their findings in the Journal of Epidemiology and Community Health (volume 56, pages 542-548, June 2002), do not recommend that people increase their drinking habits. They found that moderate drinking is more likely to create additional health risks than provide health benefits.
Heart Enzyme Linked To CHF
Scientists have already discovered that the angiotensin converting enzyme or ACE enzyme is found throughout the vascular system and leads to high blood pressure through the production of angiotensin II which causes constriction of blood vessels. Angiotenin II production can be prevented through ACE inhibitors.
Now new research indicates the presence of an additional enzyme, called ACE-related carboxypeptidase or ACE2, that may be essential in maintaining normal heart function. The research was conducted by scientists at the University of Toronto in Canada, who used specially bred mice to determine how the enzyme works. Information about ACE2 was first published two years ago. Although its structure is somewhat similar to ACE, it has an opposite effect. ACE2 breaks down angiotensin II into less harmful forms of angiotensin. Rather than being located in blood vessels, ACE2 is found in the heart, kidney, and testes.
In their study, the scientists studied rats with high blood pressure and looked for the gene that produces ACE2. They then bred mice which lacked the ACE2 gene, the ACE gene, or both. The researchers found that the mice who lacked ACE2 developed heart failure similar to heart disease in humans, but those that lacked both ACE and ACE2 did not. They believe that ACE may cause heart failure, and ACE2 blocks that by reducing angiotensin II levels.
Low levels of the ACE2 enzyme may lead to congestive heart failure, as explained in a review of the research also published in the June 20th issue of Nature. Scientists are hopeful that drugs that mimic ACE2's ability to prevent heart disease will be developed, although ACE inhibitors currently on the market are also used for this purpose.
Testing For Diabetes After Heart Attack
People who have had a heart attack already have a higher risk of having a subsequent heart attack than those in the general population, and those with Type 2 diabetes have an even greater risk. As a result, researchers are now advocating that heart attack victims be tested for diabetes before they leave the hospital.
A new study published in the journal The Lancet (volume 359; pages 2127-2128; June 22, 2002) shows that many people who have had a heart attack also have blood sugar irregularities. Doctors from Karolinska Hospital in Stockholm, Sweden tested 181 people who had had a heart attack, and found that 31% of these people had Type 2 diabetes and an additional 35% had signs of "prediabetes." When tested three months later, 25% had diabetes and 40% had signs of prediabetes.
Because people with diabetes and prediabetes have an increased risk of dying from heart disease, the researchers recommend that everone who has had a heart attack be tested for diabetes before being discharged from the hospital.
Exercise May Decrease Inflammation
Researchers have known for many years that exercise decreases the risk of heart attack, but they have not been entirely clear on the reason for this. A new study indicates that it may be the inflammation-decreasing properties of exercise that protect against heart attack.
The study included 135 African-American, Native-American, and white women, all of whom were tested for their fitness levels by exercising on a treadmill, and also had their C-reactive protein (CRP) levels measured. CRP levels indicate inflammation in the body, as it is a response to infection and injury. Chronically high levels of CRP have been associated with an increased risk of heart disease, and inflammation may be a cause of the hardening and narrowing of arteries that are often accompanied by heart attack and stroke.
The researchers, who are from the University of Utah in Salt Lake City, found that Native-American and white women who were the most physically fit also had the lowest levels of CRP in their blood. This link was not found in the African American women, and unfortunately African American women also had the highest average levels of CRP in their blood. The reason for this dissociation is not known. CRP levels varied according to the women's weight or body mass index. Those who were obese also had the highest levels of CRP and fat cells are known to increase levels of inflammatory particles.
This report is found in Circulation: Journal of the American Heart Association (volume 106, June 2002). The researchers also note that low CRP levels have been shown to reduce the risk of developing Type 2 diabetes, and this may be part of the reason that exercise reduces risk of Type 2 so greatly.
Online Doctor Visits
According to a new study, teens with Type 1 diabetes may just as safely communicate their blood sugar levels to their doctor via an e-mailed report as by going in for a face-to-face visit with their doctor.
Currently, people with Type 1 diabetes are encouraged to see their doctor once every three months. However, researchers from the University of Colorado Health Sciences Center wanted to see if these visits could be replaced by an internet exchange. Sixty-three adolescents between the ages of 14 and 20 with Type 1 diabetes participated in the study. Thirty-three of these were asked to continue visiting their doctor every three months for six months. The other thirty were given an Acculink Modem and asked to send in their glucose levels to their doctors every two weeks instead of visiting their doctor. The doctors then followed up with a phone call after every report.
The researchers found that throughout the study, the teens using the modem and those seeing their doctor regularly had the same decreases in their blood sugar levels. Also, those in the modem group were no more likely to have episodes of mild hypoglycemia than those who regularly see their doctor.
The researchers presented their findings at the annual meeting of the American Diabetes Association (June 17, 2002), and believe that the use of the modem would be a viable way for people to avoid costly office visits while still remaining healthy.
Resistance Training For Seniors
Because many health problems arise as people age, doctors emphasize the importance of staying active. A new study shows that one way of keeping fit and losing weight is resistance training with weights.
A group of 12 women and 14 men between the ages of 61 and 77 recently participated in a 25-week study conducted by researchers at the University of Alabama at Birmingham. The participants did two sets of 10 repetitions three times per week, including back extensions, leg extensions, bench presses, and bent leg sit-ups. At the conclusion of the study, researchers used CT scans to measure a particular kind of fat called intra-abdominal adipose tissue. High levels of this fat have been linked to diabetes, heart disease, and death.
Study authors found that the men and women improved their average strength by 15% and 16% respectively, and lost about 4.4 pounds of total body fat. However, women appeared to benefit more because they lost about 15 cubic centimeters of abdominal fat, while men had a slight increase in abdominal fat, although the small number of participants makes these results less dependable. Researchers are quick to encourage both men and women to participate in resistance training programs, as this training has been shown to increase the number of calories burned even when not exercising. The results of this study have been published in the journal Medicine & Science in Sports & Exercise (volume 34, pages 1023-1028, June 2002).
President Encourages Americans To Exercise
In a recent radio address, President Bush encouraged the American public to improve health statistics by exercising for 30 minutes a day, eating a low-fat diet, and refraining from smoking, doing drugs, and drinking excessively. Bush himself regularly runs and lifts weights. The federal government has estimated that one-third of all cancer and heart disease and up to 80% of Type 2 diabetes cases could be prevented if people ate a healthy diet and exercised more. Health costs of obesity were in excess of $117 billion in the year 2000, according to the Health and Human Services Department.
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