FRIDAY, Feb. 29 (HealthDay News) -- Fasting blood sugar levels are typically used to diagnose diabetes, however, a common complication of the disease that can lead to blindness begins at blood sugar levels below what is considered diabetic, Australian researchers report.

Retinopathy is a vascular condition where the small blood vessels in the eye become damaged; other complications of diabetes include heart, kidney and circulatory problems.

"Retinopathy, which is one of the complications traditionally associated with diabetes, occurs at fasting glucose levels below the threshold that is used to define diabetes," said lead researcher Dr. Tien Y. Wong, chairman of the Department of Ophthalmology at the University of Melbourne.

In the study, Wong's team analyzed three studies that looked at retinopathy among 11,405 people. The report was published in the March 1 issue of The Lancet.

The researchers found that the overall prevalence of retinopathy ranged from 9.6 percent to 15.8 percent in the general population. In addition, they didn't find evidence of a particular blood glucose level that would indicate the presence of retinopathy. In fact, 60 percent of retinopathy cases were missed by the current threshold for diabetes diagnosis, which is 7.0 mmol/L.

The finding suggests that eye damage happens much earlier and at lower blood sugar levels than what is currently used to pinpoint the presence of diabetes, Wong said. "This suggests that diagnostic threshold may have to be revised, so that we can pick up more people who are at risk of eye and other complications," he noted.

In addition to retinopathy, signs of cardiovascular disease also appear to develop at glucose levels below those defined as diabetes, Wong said.

One expert agrees that fasting blood sugar levels may not be the best way of diagnosing diabetes and those at risk for diabetes.

"It is becoming more common that studies are showing that a fasting blood sugar value is not necessarily the best way to judge diabetes or diabetes control," said Dr. Stuart Weiss, an endocrinologist at New York University Medical Center.

Weiss noted that right now there is no other marker for diabetes. However, many new studies point to the use of blood sugar levels after eating as being better markers for risk, he said.

"Fasting blood sugar is not all that helpful," Weiss said. "The problem is that a lot of our thinking is based on fasting. That's an issue we need to focus in on," he said.

More information

For more about diabetes, visit the American Diabetes Association  .

WEDNESDAY, Feb. 27 (HealthDay News) -- Women with type 1 diabetes who take less insulin than they should to try to lose weight triple their risk of dying compared to women who do not skip insulin doses, a new study finds.

"This is a very important women's health issue in diabetes," said Ann E. Goebel-Fabbri, lead author of a study in the March issue of Diabetes Care. "It happens at shockingly high rates, and, if we can detect this problem sooner and earlier, one would hope that we could direct patients to effective treatment."

Insulin treatment has been linked to weight gain; this practice of restricting insulin is referred to as "diabulimia," and is a dangerous way to shed pounds quickly. Previous studies have shown that women with diabetes are almost 2.5 times more likely to develop an eating disorder than women without diabetes. Research also suggests that diabulimia can increase the risk of complications such as foot and vision problems, along with kidney damage, but there has been little research on mortality.

People with type 1 diabetes have completely lost the ability to produce their own insulin, the hormone necessary to usher glucose into cells, where it is stored for energy. Regular injections of insulin essentially replace what the body used to produce naturally.

But shortchanging insulin doses means glucose levels are not controlled and, as the landmark Diabetes Control and Complications Trial established, persistently high blood glucose levels lead to serious complications, including eye and kidney trouble, and even death.

"Insulin is the hormone that allows the transport of glucose from the bloodstream into cells for use, so either the sugar gets used then and there for energy or it gets stored for later use," explained Goebel-Fabbri, a psychologist and investigator in the Section on Behavioral and Mental Health at Joslin Diabetes Center and an instructor at Harvard Medical School. "So, if you're not taking enough insulin, sugar increases in concentration in the blood, the body needs to find a way of excreting it, and the calories from that sugar get excreted in the urine."

Unfortunately, half of adult diabetics do not maintain recommended glycemic levels.

This study included a total of 234 women, mean age 45, who were followed for 11 years. Participants had had diabetes for a mean of 28 years by the end of the follow-up.

Almost one-third of women reported taking less insulin than they should.

These women tripled their risk of dying compared with women who did not restrict their insulin. They also died younger (45 versus 58) and had higher rates of kidney and foot problems.

Women in the two groups did not differ when it came to depression, anxiety, fear of hypoglycemia (low blood sugar), or general psychiatric symptoms. This left an eating disorder, rather than general psychological issues, as the likely culprit.

"We need to start including this kind of screening for diabetes practice," Goebel-Fabbri said.

More information

Visit the American Diabetes Association   for more on type 1 diabetes.