The 'diabetes clock' may start ticking in women years in advance of a medical diagnosis of the disease, according to a new research.

Epidemiologists at the University at Buffalo in New York have found that newly identified risk factors for diabetes found in the blood, such as markers of endothelial dysfunction, chronic sub-acute inflammation and blood clotting factors, are present early on in women who eventually progress from normal glucose status to the pre-diabetic condition.

Pre-diabetes is diagnosed when blood sugar levels are higher than normal, but not high enough to indicate full-blown diabetes. The markers weren't associated with progression from normal to pre-diabetic status in men, said the study that appeared in the February issue of Diabetes Care.

"This is one of the first reports to show that otherwise healthy women are more likely than men to show elevated levels of endothelial factors and other markers of progression to pre-diabetes," said lead author Richard Donahue.

"Because these pre-diabetic markers are not routinely assessed, and because diabetes is strongly linked with coronary heart disease, the study may help explain why the decline in death rates for heart disease in diabetic women lags behind that of diabetic men," he said.

"Previous research had shown that hypertension and cholesterol were elevated among women who later developed diabetes. However, current findings that these novel risk factors are elevated among women even earlier than previously recognised does suggest that the 'diabetes clock' starts ticking sooner for women than for men."

The study involved 1,455 healthy participants originally enrolled in the Western New York Study, a case-control investigation of patterns of alcohol consumption and risk of cardiovascular disease conducted from 1996-2001. In the current study all participants were free of pre-diabetes, type 2 diabetes and known cardiovascular disease. They received a physical examination when they entered the study and again for this six-year follow-up. Standard measures - height, weight, waist girth, blood pressure - were taken, plus blood samples to determine concentrations of fasting glucose and insulin, specific proinflammatory markers, C-reactive protein and markers of dysfunction in the endothelial tissue, the tissue lining blood vessels.

Results showed that 52 women and 39 men had progressed from normal blood glucose levels to pre-diabetic status during the previous six years.

Donahue said the question of what explains the sex difference remains to be determined, and he plans to study this in the future. He suggested that women whose blood glucose increases over time, even if it doesn't reach diabetic levels, should be screened more intensively for cardiovascular disease.