We have all heard that it is healthy to have high HDL cholesterol (good cholesterol).

But a study in the latest edition of the Journal of Clinical Endocrinology & Metabolism now shows that this is only partly true.

Because this time the researchers were not just looking at heart disease. They also looked at HDL cholesterol and diabetes…

… and that changed everything!

The authors were interested in the effects of HDL cholesterol scores on the development of diabetes – not just in HDL scores measured once, but in HDL levels measured over several visits over four years.

For data, they used health information from the Korean National Insurance System. In their sample, they included the information of 5,114,735 adults free from diabetes, who had undergone several cholesterol test between 2009 and 2013.

They immediately noticed that some of the subject’s HDL cholesterol varied from visit to visit, and from this data, they divided the subjects into four groups:

  1. People with los average HDL and low variability in their HDL scores from test to test.
  2. People with high average HDL and low variability in their HDL scores.
  3. People with low average HDL and high variability in their HDL scores.
  4. People with high average HDL and high variability in their HDL scores.

During around five years of observation, their subjects experienced 122,192 cases of diabetes, as defined by at least one insurance claim per year for a diabetes drug prescription.

They found that people with a high average HDL score and low variability in their HDL scores were the healthiest.

People with a low average HDL score or high HDL variability were the most likely to develop diabetes, and those with both a low score and a high variability had the highest risk.

Compared to the high average, low variability group:

1. The high average, high variability group was 20 percent more likely to have diabetes.

2. The low average, low variability group was 35 percent more likely to have diabetes.

3. The low average, high variability group was 40 percent more likely to have diabetes.

This means that we should try to keep our HDL cholesterol stable and high to avoid diabetes. And the same is probably true for heart disease.

But how to do we keep our CHOLESTEROL healthy?