Dr. Allard-Ratick says, "It may be time to change the way we view HDL cholesterol. Traditionally, physicians have told their patients that the higher your 'good' cholesterol, the better. However, the results from this study and others suggest that this may no longer be the case."
The current study, undertaken as part of the Emory Cardiovascular Biobank, analyzed the association between very high
values and the risk of heart attack and death.
The participants were followed up over a median follow-up period of four years during which 769 (13%) participants suffered a
or died from a heart-related cause.
‘Levels of HDL cholesterol more than 60 milligrams per deciliter is associated with higher risk of heart attack or dying from a heart-related cause.’
The key findings
of the study included the following:
- Persons with HDL cholesterol between 41-60 mg/dl (1.1-1.5 mmol/L) showed the least risk of heart attack or death due to heart disease
- However, the risk was higher in the groups that had low levels (less than 41 mg/dl) and very high levels (greater than 60 mg/dl) of HDL cholesterol, forming a U-shaped curve when plotted graphically
- Interestingly, those with HDL cholesterol levels more than 60 mg/dl (1.5 mmol/L) had a nearly twice the risk of suffering a heart attack or dying due to heart disease compared to those with optimum HDL cholesterol levels of 41-60 mg/dl (1.1-1.5 mmol/L).
- The associations remained constant even after adjusting for other confounding risk factors for heart disease such as smoking, diabetes, smoking, low-density lipoprotein (LDL or "bad") cholesterol, as well as other factors associated with high HDL cholesterol values such as race (Hispanics, non-Hispanic whites and Asians), sex and alcohol intake.
Thus, the findings of the study suggest and also support similar findings from earlier studies that found very high HDL cholesterol levels to be associated with an increased risk of heart attack and death due to heart disease.
Dr. Allard-Ratick said, "Our results are important because they contribute to a steadily growing body of evidence that very high HDL cholesterol levels may not be protective, and because unlike much of the other data available at this time, this study was conducted primarily in patients with established heart disease."
Although more studies in future may be necessary to determine the reasons why very high HDL cholesterol levels adversely affect the heart, Dr. Allard-Ratick believes that the very high levels may actually represent abnormal HDL cholesterol not doing their normal heart protective function properly. The oft-repeated mantra - "HDL cholesterol is good cholesterol" may not be true for all. Reference :
- Too much of a good thing? Very high levels of "good" cholesterol may be harmful - (https://www.escardio.org/The-ESC/Press-Office/Press-releases/Too-much-of-a-good-thing-Very-high-levels-of-good-cholesterol-may-be-harmful)