Clinically useful?
Commenting on the study for this news organization, Marilyn Tan, MD, clinic chief of the Endocrine Clinic and clinical associate professor of medicine at Stanford (Calif.) University, said, “I certainly would not recommend anyone do anything to actively lower their HDL levels. HDL levels are largely determined by genetics, diet, and lifestyle, with some effects from certain medications/supplements. Studies have demonstrated that moderately higher HDL levels may be protective for atherosclerosis.”
In the current study, she said, “Causation has not been proven, and importantly there is no evidence that reducing HDL levels reduces fracture risk. Also, this association between raised HDL levels and fracture risk has not been demonstrated consistently in other studies.”
Furthermore, she noted, the preclinical trials on which the authors based their hypothesis – that is, an association between HDL and a reduction in the number and function of osteoblasts – “has not been demonstrated widely in human subjects.”
“We have a large armamentarium of FDA-approved treatments for osteoporosis that have been clinically proven to reduce fracture risk very significantly, and these are the tools [in addition to lifestyle changes] we should use to reduce fracture risk,” Dr. Tan concluded.
John Wilkins, MD, of Northwestern University, Chicago, and Anand Rohatgi, MD, MSCS, of UT Southwestern Medical Center, Dallas, also point out some limitations of the study in a related editorial.
They note the inclusion of predominantly healthy adults with a mean age of 75, a population that could yield different findings from middle-aged cohorts with chronic illnesses, as well as a lack of clarity regarding the possible role of alcohol intake among the study participants.
Furthermore, the editorialists write, although significant associations were shown in this study, “models were not adjusted for detailed measures of exercise/activity, triglycerides, or any other lipids, including other HDL compositional measures such as HDL-P or ApoA-I levels. There was no assessment of whether HDL-C improved discrimination, reclassification, or any other validated measures of risk prediction performance.
“Taken together,” they conclude, “this study alone leaves several unanswered questions as to whether high HDL-C could be a useful biomarker to detect fracture risk.”
No commercial funding was disclosed. The authors report no relevant financial relationships.
A version of this article originally appeared on Medscape.com.