Simple Blood Test Predicts Who Might Develop Type 2 Diabetes Among Healthy Women

Doctors may have identified a new and simple way to predict risk for developing Type 2 diabetes. The result of a simple blood test may be the earliest alert to doctors and patients to implement lifestyle changes that may delay or prevent the onset of the disease….

Samia Mora, M.D., and colleagues at Harvard Medical School and the Brigham and Women's Hospital used Nuclear Magnetic Resonance (NMR) to investigate the relationship of NMR-measured lipoproteins and the development of future Type 2 diabetes. The outcome of Dr. Mora's work showed that NMR-measured lipoprotein particles were associated with development of Type 2 diabetes, independent of other risk factors, particularly HDL-cholesterol and triglycerides measured by standard laboratory methods.

According to Dr. Mora, "Our findings indicate for the first time that even before the onset of clinical Type 2 diabetes, the size and number of the lipoprotein particles may indicate which women go on to develop future disease. This could provide an important opportunity for a woman with a normal blood glucose, but an abnormal NMR lipoprotein test result, to intervene early by following a healthy diet, losing weight, and increasing her physical activity level, all known ways to reduce her chance of developing diabetes even years before she gets a high glucose reading."

Doctors typically look for increases in glucose and triglycerides, and decreases in HDL cholesterol, to determine if a patient is becoming pre-diabetic. Even before changes in glucose levels are detectable, there are significant changes in the metabolism of cholesterol and triglycerides.

LDL "bad" cholesterol, HDL "good" cholesterol and triglycerides, are carried throughout the body inside molecules called lipoprotein particles. The particles travel into artery walls where they deposit the cholesterol, which forms artery-clogging plaque. Researchers wanted to know the significance of the particle size and number in apparently healthy individuals: could these readings predict future disease? Could they, in fact, predict who might develop Type 2 diabetes in time for early intervention?

The researchers conducted a study of 26,836 initially healthy women who were then followed for 13 years, during which 1,687 developed Type 2 diabetes. Dr. Mora noted, "Our study, which was conducted in a large population of healthy women, found that larger LDL and HDL particles were associated with lower risk and smaller LDL and HDL particles were associated with higher risk of diabetes. Even in women with normal triglyceride and HDL cholesterol measured by standard tests, having smaller LDL particles imparted higher risk of diabetes."

The team concluded that NMR-measured lipoprotein particle size and number provide an opportunity to better predict a healthy woman's chance of developing future diabetes, a type of early warning system. "Our finding suggests that these lipoprotein alterations may occur years before onset of overt hyperglycemia and clinical diagnosis of diabetes, providing a potential opportunity for the early detection and prevention of Type 2 diabetes and its complications."

Although standard laboratory tests can be used to measure the cholesterol and triglycerides carried by the particles, these tests do not provide a reliable indication of the number or size of the particles in the bloodstream. Particle number and size can be measured from a small blood specimen using another test (NMR), technology that has been used in research settings for over 40 years. More recently, NMR has been used in the clinical laboratory to determine particle number and size in the blood.

Mental decline from diabetes can start in middle age

(Reuters Health) - Diabetes can lead to a decline in memory, thinking speed, and mental flexibility in middle age, but controlling the blood sugar disorder might prevent some of these effects, new research from the Netherlands suggests.

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While the mental decline may be invisible to the individual, the fact that the drop-off starts accumulating in middle age puts diabetics at greater risk later on because of reduced "brain reserves," Dr. David Knopman, of the Mayo Clinic in Rochester, Minnesota, told Reuters Health.

"Like a bicycle tire that's been partially deflated -- you'll be OK riding around but if you develop another little leak you'll be much closer to a flat tire much faster," said Knopman, who was not involved in the Dutch study.

Astrid Nooyens and colleagues at the National Institute for Public Health and the Environment in the Netherlands examined the health records and mental acuity scores of more than 2,600 men and women between the ages of 45 and 70 who enrolled in a large ongoing study into lifestyle effects on health.

At the five-year mark, of the 139 participants with type 2 diabetes, 61 were diabetics at the beginning of the study and 78 developed the chronic disease within the next five years.

The study confirmed the findings of earlier research, by Knopman and others, of an association between diabetes and declines in such mental functions as the ability to think quickly and recall words, but this is the first project to test memory and demonstrate how quickly the drop-off can occur.

Over a five-year period, decline in overall mental functioning in people with type 2 diabetes, while small, was nearly 3 times more pronounced than in non-diabetics.

But it didn't take many years for the impact to be felt. Even those who developed diabetes after beginning the study saw twice as much of a decline as their non-diabetic counterparts.

Compared to the "healthy" participants, participants who had long-term diabetes registered the largest declines in mental function. Those who developed diabetes during the trial saw less pronounced declines than their long-term counterparts in most areas except information processing, where they appeared to do a little better than the "healthy" people.

Type 2 diabetes is characterized by high blood sugar levels caused by the body's inability to process sugar properly. The illness can usually be controlled through diet and exercise but may also require drugs.

The Nooyens group found that while memory continues to decline for those with diabetes, the drop-off in thinking speed appears to occur in the first five years and then level off. That led the authors to suggest that early treatment and control of blood sugar levels could help thinking speed, but probably not memory, they note in the journal Diabetes Care.

The researchers found that for a small group of people who had lived with diabetes for nearly seven year, blood sugar levels did not explain the entire decline in mental function. In those people, they suspect other conditions related to diabetes such as high blood pressure and obesity.

The study did not look at whether patients with well-controlled diabetes experienced less mental decline compared to their poorly controlled counterparts, although the authors point out that there are other reasons, such as heart disease, to control sugar levels as well.

They also note that the random blood tests of both the long- and short-term diabetics suggested what treatment they were getting was "insufficient."

SOURCE: link.reuters.com/xyd69k Diabetes Care, online June 2, 2010