A University of Pittsburgh Graduate School of Public Health research has discovered that advanced blood levels of high-density lipoprotein (HDL) or 'good' cholesterol, typically believed to defend against heart trouble, may do the opposite in females suffering from type 1 diabetes.

HDL cholesterol is called 'good' cholesterol as it helps prevent arteries from getting blocked.

The researchers said that increased levels of HDL cholesterol, more than 60 milligrams per deciliter (mg/dL), generally defend against heart ailments, whereas low levels raise the chance of heart problem.

Study scientists discovered that the occurrence of heart problem augmented in both males and females having diabetes who had lower levels of HDL - below 47.5 mg/dL. For men, as levels of HDL increased, their incidence of heart disease decreased.

The same was detected for females, except in those with very high levels of HDL (over 80 mg/dL) whose chance of heart disease heightened substantially. Study authors were unable to draw a meaningful comparison to male participants since only a few had HDL over 80 mg/dL.

Tina Costacou, lead author of the study and assistant professor of epidemiology, University of Pittsburgh Graduate School of Public Health stated, "Although high levels of HDL are typically associated with decreased risk for cardiovascular disease, this may not be the case for women who have type 1 diabetes and HDL in the upper ranges."

"We need to examine this relationship further, but our study suggests that too much of a good thing may not always offer protection and may even be harmful for women with type 1 diabetes," Costacou added.

The research is being presented at the 70th Scientific Sessions of the American Diabetes Association. (With Inputs from Agencies)