AUG 04, 2016

Contradicting Results Associate LDL with Lower Risk for Diabetes

WRITTEN BY: Kara Marker
Findings from a new study made connections between increased low-density lipoprotein cholesterol (LDL-C) and triglyceride levels with an increased risk of coronary artery disease, results that didn’t raise any eyebrows. Surprisingly though, the same study linked increased levels of LDL-C, high-density lipoprotein cholesterol (HDL-C), and potentially triglyceride levels with a lower risk of type 2 diabetes. Wait - what?
The American Heart Association refers to LDL and the “bad” type of cholesterol because of its contribution to plaque buildup, which can lead to dangerous atherosclerosis in blood vessels. HDL, on the other hand, is the “good” kind of cholesterol as it helps to reverse the effect of LDL-C by removing it from collecting in the arteries. So when scientists from the recent JAMA Network Journals study observed the connection, they weren’t quite sure what the results meant.

“Our findings inform potential expected downstream consequences of interventions affecting lipid traits,” said Michael V. Holmes, MD, PhD, and his team. “And provide cautionary evidence that therapeutics that lower LDL-C and triglyceride levels may have dysglycemic effects.”

Holmes and the rest of the researchers performed genome-wide association studies using Mendelian randomization to look for “distinct associations” between different types of lipids and their relationship to higher or lower risk for coronary heart disease or type 2 diabetes. After receiving the contradicting results, they also considered that it could be the use of statin therapy to lower LDL-C levels that could be causing the risk of type 2 diabetes. Or perhaps, they thought, it could just be LDL-C medications in general. Regardless, there are still a lot of questions about what the results from this study mean.

“Large-scale genetic and clinical investigations are needed to clarify the effects of pharamcologic lowering of LDL-C and triglyceride levels to gauge dysglycemic associations,” the authors wrote. 

Some scientists believe that the researchers’ methods, using mendelian randomization, are reliable for determining association of LDL-C and triglycerides with coronary artery disease, but not for associating LDL-C, HDL-C, and triglycerides with type 2 diabetes. “It seems that other approaches are required to further evaluate the causal relevance of each of these lipid fractions in association with type 2 diabetes,” said Danish Saleheen, MBBS, PhD, from the University of Pennsylvania, Philadelphia.

This study was recently published in the journal JAMA Cardiology. 
 


Sources: NC Research Campus, American Heart Association, The JAMA Network Journals