Researchers in the US have found that increasing levels of "good" cholesterol reduces the risk for heart attack and stroke among patients with diabetes. Patients whose high-density lipoproteins (HDL) levels decreased had more heart attacks and strokes, according the researchers. The observational study, one of the largest of its kind, examined the medical records of more than 30,000 patients with diabetes."Our study adds to the growing body of evidence that raising HDL levels may be an important strategy for reducing heart attack risk," said study lead author Gregory Nichols, PhD, senior investigator with the Kaiser Permanente Center for Health Research in Portland, Ore."This is promising news for patients with diabetes, who already have an increased risk for heart problems. Raising their good cholesterol may be one more way for these patients to reduce their risk," said Suma Vupputuri, PhD, co-author and investigator with the Kaiser Permanente Center for Health Research in Atlanta.Those who took part in the study had at least two HDL cholesterol measurements between 6 and 24 months apart. Once cholesterol measurements were obtained, researchers followed the patients for up to eight years to check if they had been omitted to hospital for a heart attack or stroke. Patients whose HDL levels increased had 8 percent fewer heart attacks and strokes than patients whose HDL levels remained the same.Meanwhile, those whose HDL levels decreased were 11 percent more likely to suffer heart attacks and strokes.