Holding back diabetes: The one-point difference

By Janis Siegel,

JTNews Columnist

It’s only a tiny percentage point of difference, but new diabetes research from Tel Aviv University shows that a seemingly insignificant difference in blood sugar readings could buy you a lot of valuable time — and maybe even save your life.
In January 2014, researchers at TAU shared their study results showing that a commonly used and reliable diabetes-screening blood test, the HbA1c test, used to identify patients at high risk for Type 2 diabetes, can also identify many more non-diabetic patients who may have a predisposition for its precursor — a condition called prediabetes.
The research published in the European Journal of General Practice in 2013 should give more people hope that they can avoid the chronic and often life-threatening disease if they are armed with earlier information.
In the study, M.D. thesis candidate Nataly Lerner’s team from the Department of Family Medicine in the Sackler Faculty of Medicine reviewed the medical records of 10,201 patients in Israel all of who were over the age of 20 and non-diabetic at the time. The study cohort included nearly equal numbers of male and female subjects, however more than 75 percent of all the subjects were overweight, which Lerner said mimicked the general population and was not the determining factor in the study for the development of the disease. Each had been given the HbAc1 test between 2002 and 2005.
What the researchers found was that within five to eight years of their HbA1c test, 22.5 percent of those patients who eventually developed Type 2 diabetes had lower blood-glucose-level readings — 5.5 percent — below the standard threshold of 5.7 percent typically used for the test.
“Age and low socio-economic status, after controlling for baseline HbA1c, and overweight, were not found to associate with the progression to diabetes,” wrote Lerner about his study participants. “This is despite the increased prevalence of diabetes that has been observed with age, exceeding 20 percent of the population in Israel for the ages 65—74.”
After further analyzing the data, researchers also found that each increase of 0.5 percent indicated that a patient was two times more likely to develop Type 2 diabetes.
“The risk to develop Type 2 diabetes was exponential, almost doubling with each increase of 0.5 percent of HbA1c,” wrote Lerner.
The good news is that the progression from the “prediabetic” stage to the onset of Type 2 diabetes is not inevitable, say researchers.
If this blood marker is picked up early enough with this test, people can make lifestyle changes such as taking up exercise, losing weight, and eating a healthy diet — all part of a strategy that can bring your blood sugar back to normal levels.
“As expected,” wrote Lerner about the overall population, “weight was shown to be an important, independent risk factor for Type 2 diabetes, supporting early screening among overweight individuals.”
The American Diabetes Association currently puts the HbA1c range indicating a prediabetes risk between 5.7 percent and 6.4 percent.
“The ADA 2013 recommendations include the use of HbA1c testing,” wrote Lerner, in addition to conducting additional tests.
Also known as adult-onset or noninsulin-dependent diabetes, Type 2 diabetes affects the way your body metabolizes sugar — either by resisting insulin, a hormone that regulates the way sugar enters your cells, or not making enough insulin to maintain normal sugar levels in the body. Left untreated, the disease can be life threatening.
People diagnosed with impaired glucose tolerance, IGT, or impaired fasting glucose, IFG, depending upon which test was used, have higher than normal blood-glucose levels that were not previously thought to be high enough to be diagnosed as diabetes.
One advantage of the HbA1c test over the IGT and the IFG is that it doesn’t require the patient to eat or drink a particular food. Another benefit to the patient and the doctor is that an A1c test can show a patient’s average blood sugar levels over a longer period of time, indicating levels for as long as the past two or three months.
Previously, a normal HbA1c reading showing little or no risk of diabetes was considered to be between 4 and 5.6 percent. However, this new research would make a 5.4 percent reading a prediabetes diagnosis.
“We suggest HbA1c testing of patients at risk of developing diabetes, for example, according to BMI and history of cardiovascular disease, to promote stratification of a target population,” concluded Lerner.

Longtime JTNews correspondent and freelance journalist Janis Siegel has covered international health research for SELF magazine and campaigns for Fred Hutchinson Cancer Research Center.