Hemoglobin A1c Levels Predict Risk of Peripheral Arterial Disease
on Tuesday, April 18 @ 14:03:46 CDT
The results suggest that poor glycemic control, as indicated by elevated HbA1c levels in individuals with diabetes, is associated with an increased risk of PAD independently of other known risk factors.
In adult patients with diabetes, increased hemoglobin A1c (HbA1c) levels are associated with an elevated risk of peripheral arterial disease.
Dr. Elizabeth Selvin from Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland stated that, "This study is one of the first prospective studies to examine the association of HbA1c and the development of peripheral arterial disease (PAD) in diabetics looking specifically at different manifestations of PAD.” Dr. Selvin and colleagues used data from The Atherosclerosis Risk in Communities study to investigate whether HbA1c is related to PAD in 1,894 middle-aged adults with diabetes.
The risk of hospitalization related to PAD increased with increasing tertiles of HbA1c level, the authors report, as did the risk of intermittent claudication.
Specifically, patients in the second and third tertiles of HbA1c level were 53% and 64% more likely, respectively, than those with the lowest HbA1c to have PAD, as defined solely on the basis of a low ankle-brachial index (ABI below 0.9), the results indicate.
The researchers note that trends toward higher risk of PAD with higher HbA1c level were evident for all manifestations of PAD, regardless of whether or not diabetes had been diagnosed.
Fasting blood glucose levels were also associated with the risk of PAD, the report indicates, but the association was much weaker than that observed for HbA1c level.
"Our results suggest that poor glycemic control, as indicated by elevated HbA1c levels in individuals with diabetes, is associated with an increased risk of PAD independently of other known risk factors," Dr. Selvin concluded. "This association was particularly strong for the symptomatic, more severe manifestations of PAD, including intermittent claudication and PAD-related hospitalizations."
"Ultimately, our results suggest that efforts to improve glycemic control in persons with diabetes may substantially reduce the risk of PAD development," Dr. Selvin added.
Diabetes Care 2006;29:877-882.
on Tuesday, April 18 @ 13:56:49 CDT
Even a short treatment period can have an effect on neuropathic symptoms.
Injections of botulinum toxin type A relieve pain in an animal model of diabetic neuropathy, according to new research.
A second presentation at the meeting suggests that a combination of Ginkgo biloba extract and folate is superior to placebo in reducing symptoms of diabetic neuropathy, even though nerve conduction velocities are unaffected.
Dr. Zdravko Lackovic, from Zagreb University in Croatia, said, "We previously showed that botulinum toxin reduces hypersensitivity in a model of surgical neuropathy."
His team's current research involved what they considered an animal model that more closely represents diabetic neuropathy, he said. They injected alloxan subcutaneously into rats, and used those that developed blood glucose levels > 15 mmol/L after 5 days. "About 60% of the diabetic rats developed mechanical hyperalgesia," which is similar to diabetic neuropathy, Dr. Lackovic noted.
Five days after they injected the plantar surface of the paw pad of diabetic rats with 5 or 7 U/kg of botulinum toxin, the animals became less sensitive to formalin injection, as demonstrated by reductions in flinches and shaking of the injected paw, compared with diabetic rats treated with saline instead of the toxin.
Mechanical sensitivity was also reduced in the diabetic rats treated with botulinum toxin, an effect that lasted 15 days.
"To our knowledge, this is the first demonstration that a single peripheral injection of botulinum toxin might have a long-lasting antinociceptive effect in diabetic neuropathy," the investigators conclude in their meeting abstract.
For the research reported in the second presentation, Dr. Susanne Koeppen, from the University of Essen in Germany, and her colleagues recruited 60 diabetic patients with polyneuropathy. The subjects were randomly assigned to Ginkgo biloba extract (EGb), folate, both agents, or placebo.
EGb 50 mg and folate 15 mg and placebo were administered by IV for 14 days, then as tablets three times daily for 14 days (EGb, 80 mg and/or folate 4 mg or placebo).
Dr. Koeppen stated that, "We found out that all three active treatments were superior to placebo, with the best effect seen with the combination of folate and EGb." "I think it is important to know that even a short treatment period can have an effect on neuropathic symptoms," she added, even though there were no changes in electrophysiologic tests.
Reported at the American Academy of Neurology's annual meeting in San Diego.
on Tuesday, April 18 @ 13:59:55 CDT
Shock-wave lithotripsy (SWL), a noninvasive technique that uses sound waves to sonically disintegrate stones within the urinary track, appears to increase the risk of diabetes and hypertension (high blood pressure).
"This is a completely new finding," lead author Dr. Amy Krambeck, from the Mayo Clinic in Rochester, Minnesota, said in a statement. "We can't say with 100 percent certainty that the shock wave treatment for the kidney stones caused diabetes and hypertension, but the association was very strong."
The findings are based on a study of 578 kidney stone patients who were treated with SWL in 1985 and sent a follow-up questionnaire in 2004. Roughly 59 percent of the subjects responded to the questionnaire. The control group consisted of 288 matched patients who had their stones treated nonsurgically.
At follow-up, SWL-treated patients were 47 percent more likely to have hypertension than were controls. The risk of hypertension was strongest with bilateral SWL, the report indicates.
SWL was also linked to diabetes. Nearly 17 percent of SWL-treated patients developed diabetes during follow-up and treatment with SWL more than tripled the risk of diabetes. The risk of diabetes was directly related to both the number of shocks given and the intensity of treatment.
SWL may promote hypertension by causing scarring in the kidneys and altering the secretion of blood pressure-modulating hormones, the authors hypothesize. The link with diabetes may relate to damage inflicted upon the pancreas, they add.
Senior author Dr. Joseph W. Segura, also from the Mayo Clinic, emphasized that the current findings do not mean that SWL should be abandoned. "Despite the risks, SWL still can save the day for patients, and it would be a mistake to put it on the shelf," he added, noting that other therapies for stone removal carry their own risks as well.
Journal of Urology, May 2006.
on Tuesday, April 18 @ 13:57:57 CDT
Researchers reported that angiotensin-converting enzyme (ACE) inhibitors can improve coronary flow velocity reserve (CFVR) in patients with type 2 diabetes.
However, the researchers found that treatment with the angiotensin II type 1 receptor antagonist candesartan did not affect CFVR.
Both types of drugs have shown evidence of benefit in diabetic patients, Dr. Takayuki Kawata of Chiba University Graduate School of Medicine and colleagues write. Acute infusion of ACE inhibitors has been shown to increase coronary perfusion in diabetic patients, they add, but it is not clear whether the two drugs' effects on coronary circulation in these patients are similar.
To investigate, the researchers randomly assigned 24 patients with type 2 diabetes to 2 mg per day of the ACE inhibitor temocapril or 8 mg per day of candesartan. CFVR was calculated at the beginning of the study and after four weeks of treatment. It was also measured in eight healthy controls.
CFVR before treatment was 2.74 for patients in the temocapril group and 2.65 for patients on candesartan. It was 3.53 in the controls. After treatment, CFVR rose to 3.31 in the temocapril group, but remained the same in the candesartan group. Both drugs produced a similar reduction in blood pressure.
The findings suggest that temocapril's effects on coronary circulation in diabetic patients are independent of angiotensin antagonism, Dr. Kawata and his team note. The drug could improve coronary circulation by increasing bradykinin availability, the researchers suggest.
Thus they conclude that ACE inhibitors, but not angiotensin II type 1 receptor antagonists "may have beneficial effects on the coronary microangiopathy associated with type 2 diabetes mellitus."
Am Heart J 2006;151:798.e9-798.e15.
DID YOU KNOW:
About 15% of people with diabetes who have a foot ulcer will need an amputation, that is completely preventable with better blood glucose control!
Great article Daphne, with the constantly increasing numbers of diabetics in this country.
And Janet, you are so right. If people would only follow their treatment regimens, use good hygiene, and visit their podiatrist regularly they could be saved such traumatic procedures. And, it seems that once the amputations start, there is no end to it.
With poor circulation, and a suppressed immune system it is so important to take care of even the slightest injury, wound or lesion.
Fri Feb 9, 2007 3:04PM EST
NEW YORK (Reuters Health) - In adults with type 2 diabetes, a common diabetes-related complication of the eye called retinopathy is associated with an increased risk of dying within in a given period of time, a study shows.
Retinopathy arises when diabetes damages the tiny blood vessels of the retina, the light-sensitive tissue at the back of the eye. It can lead to blurred vision and blindness if unchecked.
Dr. Markku Laakso, from the University of Kuopio in Finland, and colleagues compared the outcomes of 425 men and 399 women with type 2 diabetes who were divided into three groups based on results of eye exams: no retinopathy, background (early) retinopathy, or more advanced "proliferative" retinopathy. All of the subjects were free from heart and vascular disease initially. They were followed for 18 years.
In women, proliferative retinopathy was associated with a 2.9-fold increased risk of death from all causes. In women, this type of retinopathy was also associated with a 3-fold increased risk of cardiovascular death and a nearly 5-fold increased risk of coronary heart disease death.
Risks for death were also elevated, albeit to a lesser extent, in women with background retinopathy.
In men, proliferative retinopathy was significantly associated with death, increasing the risks of all-cause, cardiovascular, and coronary heart disease mortality by 3.05-, 3.32-, and 2.54-fold, respectively.
The association between retinopathy and mortality was independent not only of conventional cardiovascular disease risk factors but also of blood sugar control and duration of diabetes, the authors note.
SOURCE: Diabetes Care, February 2007.
on Tuesday, February 06 @ 21:32:15 CST
Researchers have identified a group of proteins that may play critical roles in causing blood vessel leakage in the eyes of people with two forms of diabetic retinopathy.
The Juvenile Diabetes Research Foundation said that the findings could suggest new therapeutic targets for the treatment of proliferative diabetic retinopathy and macular edema, and could provide new opportunities for treating cerebral swelling caused by head injury, stroke and other conditions.
Dr Feener, director of Joslin's Proteomics Core, which hosted the study, said: "By analyzing the protein composition in the human vitreous, we have identified a new group of molecules that may improve our understanding of the disease processes that contribute to diabetic retinopathy.
"By studying the actions of these proteins in both the retina and the brain, we have shown that our findings may have broad relevance for neurovascular leakage and swelling."
Diabetic retinopathy is one of the most common complications of diabetes and is characterized by a range of abnormalities that develop from damage caused by high blood glucose levels. Proliferative diabetic retinopathy is diagnosed when the retina begins to form new blood vessels to counteract this damage, which in turn often bleed and blur or block vision.
More than 700,000 patients in the US have proliferative diabetic retinopathy, and more than 63,000 patients develop it annually.