THURSDAY, March 6 (HealthDay News) -- Chronically high blood glucose levels disable the molecular switch that normally turns off sugar production in the liver in response to increasing insulin levels, a California study finds.

This finding suggests that inhibiting the enzymatic pathway that disables the "sugar-off" switch (CRTC2) may help lower glucose levels in people with diabetes and reduce long-term complications associated with the disease, the researchers said.

The study, by researchers at the Salk Institute for Biological Studies, in La Jolla, Calif., is published in the March 7 issue of Science.

In healthy people, the CRTC2 switch turns on glucose production in the liver when blood glucose levels decline during the night. After a meal, insulin shuts down CRTC2, thus ensuring that blood sugar levels don't rise too high.

But in many people with type 2 diabetes, CRTC2 no longer responds to increasing insulin levels. As a result, the liver keeps on pumping out glucose, even if blood glucose levels are already elevated.

In research with mice, the Salk team focused on the hexosamine biosynthetic pathway. Activation of this pathway promotes the addition of sugar molecules to proteins, a process called O-glycosylation.

"It had been known that increases in the concentration of circulating glucose activate the hexosamine biosynthetic pathway. But we had no idea that the resulting O-glycosylation would lock CRTC2 in the 'on' position," study first author Renaud Dentin said in a prepared statement.

Dentin's team decreased the activity of the hexosamine biosynthetic pathway in insulin-resistant diabetic mice and in mice fed a high-fat diet (both groups had high blood sugar levels) and found a marked improvement in glucose tolerance and insulin sensitivity.

More information

The American Diabetes Association has more about hyperglycemia  .

TUESDAY, Feb. 26 (HealthDay News) -- A national effort is needed to deal with the effects of high blood sugar in heart patients, says an American Heart Association scientific statement released Monday.

The statement highlights a number of unanswered questions about the condition, also known as hyperglycemia, in people hospitalized with acute coronary syndrome (ACS), which includes heart attack and a variety of other cardiovascular conditions.

"Although studies indicate that one-fourth to one-half of ACS patients have hyperglycemia when they arrive at hospital, elevated blood sugar is frequently ignored despite being strongly associated with increased mortality," writing committee chair Dr. Prakash Deedwania, chief of cardiology at the VA Medical Center and the University of California, San Francisco, in Fresno, said in a prepared statement.

A number of studies have shown that hospitalized ACS patients with high blood sugar have increased rates of in-hospital complications and death. But much more needs to be learned about the link between hyperglycemia and poor outcomes in these patients. For example, it's unclear whether elevated blood sugar levels in ACS patients are a marker for heart muscle damage or actually cause the damage, Deedwania noted.

Since evidence about how best to approach glucose management in ACS patients is still being gathered, the AHA statement provides "a general reference" for medical teams treating these patients.

The statement recommends that all ACS patients with elevated blood sugar be screened for diabetes or prediabetes as part of their in-hospital evaluation. Blood sugar should be kept in the range of 90 to 140 mg/dL for ACS patients who have significant hyperglycemia on admission and are placed in the intensive care unit. Blood sugar levels should be kept below 189 mg/dL for ACS patients who aren't in the ICU.

The statement is published in the Feb. 26 issue of Circulation.

"This is a call to action for organizations such as the National Institutes of Health [NIH] to design appropriate large, randomized clinical trials where several of these critical and clinically important questions can be answered. Only then will we be able to find and implement treatments that may reduce deaths," Deedwania said.

More information

The American Diabetes Association has more about hyperglycemia  .

(HealthDay News) -- A common cold, flu or infection that is an inconvenience to many people can cause much more serious health problems in diabetics.

When you're sick, your body is under stress and releases hormones that can affect your blood sugar. So it's important to know how to take care of yourself.

Here are suggestions for diabetics on dealing with an illness, courtesy of the American Diabetes Association:

• Closely monitor and regulate your blood sugar, which can fluctuate more than usual while you're sick.
• Keep a notebook where you record your blood sugar and urine ketone levels.
• Talk to your doctor to see if your medications need to be adjusted when you're sick. Have a plan ready ahead of time.
• In advance of illness, prepare a list of contact names and phone numbers of your doctor, dietitian, and diabetes educator.
• Know when you should call your doctor. For instance, if you've been sick for an extended period or can't get your blood sugar under control.