Dr Gregory Nichols and his team from the Kaiser Permanente Centre for Health Research in Portland, Oregon, examined the effect of HDL levels on cardiovascular risk.
The researchers said that increasing HDL cholesterol levels 'may provide important CVD benefits'. They believe that increasing HDL cholesterol may be less beneficial in people with diabetes than in those without the condition.
Therapies designed to increase HDL cholesterol levels in those with low levels might also help cut cardiovascular risk in others by helping them maintain their HDL levels, the researchers said.
But they believe that any such strategy would need to form part of a multifactorial strategy aimed at reducing patients' cardiovascular risk.
In the study, HDL levels were repeatedly measured in 30,067 people with type-2 diabetes: twice within two years and then again around five years later.
These measurements were then linked to information on whether or not the study participants had been being admitted to hospital for a stroke or other cardiovascular event.
After an average of 4.7 years, 10% of participants in the study had been admitted to hospital for a cardiovascular event.
Dr Nichols and his team calculated that an increase of at least 6.5mg/dl was associated with an 8% reduced risk of cardiovascular disease (CVD). On the other hand, a decrease of at least 6.5mg/dl was associated with an 11%increased risk of CVD.
The researchers pointed out that, as an observational study, their research was not able to investigate the causal relationship between HDL cholesterol changes and hospital admissions for cardiovascular events. However, they estimate that each 5mg/dl increase in HDL cholesterol was associated with a 4% reduced risk of cardiovascular admission.
'Our results add to the growing body of evidence that increasing the HDL cholesterol levels might be an important strategy for CVD risk reduction,' Dr Nichols and his team said.
'The prevention of HDL cholesterol decreases could be equally important.'
