Diabetes Linked to Higher Parkinson's Risk

People who have type 2 diabetes are more likely to develop Parkinson's disease as they age, though researchers are uncertain what accounts for the link between the two diseases, according to a new study being published in the April issue of Diabetes Care.

The study, by researchers in Finland, is the first large prospective study to find type 2 diabetes to be a risk factor for Parkinson's disease, a movement disorder characterized by muscle rigidity and tremors.

According to the authors, people with type 2 diabetes are 83 percent more likely to be diagnosed with Parkinson's than people in the general population. The study found the association between the two diseases existed for both men and women, independently of other confounding factors.

"Diabetes might increase the risk of Parkinson's disease partly through excess body weight," the researchers hypothesized, since their work showed that excess body weight was also associated with an elevated risk of Parkinson's disease. However, they concluded that more research needed to be done to fully understand the mechanisms behind this link.

Soy Nut Consumption Reduces Markers of Inflammation

Eating soy nuts instead of red meat decreases some markers of inflammation and improves endothelial function in postmenopausal women with a collection of cardiometabolic risk factors, a new study by researchers at Isfahan University of Medical Sciences in Iran and the Harvard School of Public Health found. In previous studies by the same group, subjects who ate soy nuts also showed improvements in their lipid profiles, suggesting that soy may improve cardiac health among a subgroup of women.

Previous research has looked at the effect of soy on inflammatory markers and endothelial function in the general population, but this was the first study to look more narrowly at how eating soy nuts (versus soy protein) would specifically affect postmenopausal women who already had a number of metabolic abnormalities. Consuming soy protein did not produce the same benefits, the researchers found.

Women (and men) who have certain cardiometabolic risk factors (abdominal obesity, high blood pressure, high cholesterol and insulin resistance) are at high risk for type 2 diabetes and for heart disease, the number one killer of people with diabetes. Studies have shown that lifestyle changes, such as losing moderate amounts of weight and increasing physical activity, can substantially reduce the chances of developing diabetes for people who already have these risk factors.

"A well-balanced meal plan should be part of any program designed to lose weight or improve overall health. This study shows that adding soy nuts to your diet -- and eating less red meat -- could be an important part of that meal plan," said lead researcher Dr. Leila Azadbakht, at the Isfahan University of Medical Sciences Department of Nutrition in Iran.

Soy is also often used as an alternative or adjunct to hormone replacement therapy in postmenopausal women. The researchers note that the mechanisms by which soy affects the inflammatory state may be related to the effects of soy phytoestrogens, which mimic hormone replacement therapy. However, more research needs to be done to understand the mechanisms through which soy affects inflammation and endothelial function. It is also unclear whether other groups of postmenopausal women would benefit as much as those participating in this study who had a number of high risk factors for diabetes and heart disease.

Weight-Loss Surgery Reduces Insulin Resistance, Improves Beta Cell Function

Bariatric surgery -- any of several procedures designed to reduce how much a person eats or how many calories their bodies absorb -- can reduce insulin resistance and improve beta cell function in severely obese people, regardless of whether they lose any weight, according to a study by researchers in Italy.

With the number of obese people rising rapidly in the U.S. and around the world, bariatric surgery has been growing in popularity. Previous research has shown this surgery can restore glucose tolerance in the majority of severely obese people. But this study found it could also improve beta cell function, regardless of how much weight a person does or doesn't lose after surgery.

Obesity greatly increases a person's risk of developing type 2 diabetes, which is characterized by insulin resistance and impaired beta cell function.

"Why these surgeries would improve beta cell function and glucose tolerance, independent of weight loss, remains unclear," said lead researcher Dr. Ele Ferrannini, Department of Internal Medicine and CNR Institute of Clinical Physiology, University of Pisa School of Medicine, Italy. "But obviously the fact that it does improve beta-cell function could make bariatric surgery a useful tool in the prevention of diabetes in the severely obese patient."

Note: ADA clinical practice guidelines recommend that bariatric surgery may be considered for some individuals with type 2 diabetes who also have a BMI of 35 or higher. While this can result in marked improvements in glycemia, the long-term benefits and risks of bariatric surgery in individuals with pre-diabetes and diabetes continue to be studied.

Diabetes Care, published by the American Diabetes Association, is the leading peer-reviewed journal of clinical research into the nation's fifth leading cause of death by disease. Diabetes also is a leading cause of heart disease and stroke, as well as the leading cause of adult blindness, kidney failure, and non-traumatic amputations. For more information about diabetes, visit the American Diabetes Association Web site http://www.diabetes.org or call 1-800-DIABETES (1-800-342-2383).

Contact: Rachel Morgan, ADA

(703) 549-1500 ext. 2290