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.