NMR spectroscopy uses radio waves to analyze the size and concentration of lipoproteins – the small spheres that carry cholesterol around the body and deposit it in various locations, such as the coronary arteries or the liver.
Results of this study may be especially important now that the new heart health guidelines are projecting that as many as 36 million Americans should be taking cholesterol-lowering drugs. However, research has shown that the cholesterol-lowering effects of these medications may vary according to the individual.
"By evaluating specific medications with the NMR technology, physicians will be better able to select cholesterol medications that will have optimal results for the patient depending on his or her lipoprotein size and concentration," explained Robert Rosenson, M.D., director of the Preventive Cardiology Center at Northwestern University Medical School and a cardiologist at Northwestern Memorial Hospital.
"Ultimately, this will help patients get effective and even life-saving help quicker, and reduce the cost often involved in switching therapies," Rosenson said.
In a study to be published in an upcoming issue of the journal Atherosclerosis, Rosenson and colleagues analyzed the effect of a particular cholesterol-lowering drug, pravastatin, over a six-month period in a group of 262 patients with high-risk heart disease. Paravastatin belongs to the popularly prescribed class of statins. Several million Americans currently are receiving statin therapy to lower cholesterol levels.
"In the past, we had thought that a simple lipid test [blood test] could show us how well a particular cholesterol-lowering medication was working. But by using this new technology -- which gives us significantly more data than a cursory lipid test -- we found the medication is suitable for a broader base of patients than originally thought," Rosenson said.
The researchers found, in contrast to findings from earlier studies, pravastatin was equally effective in lowering LDL cholesterol levels [bad cholesterol] in all patients regardless of the LDL size at the beginning of the study.
Study participants with small LDL particles gained at least as much benefit from the medication as those with large LDL. Results of the study showed reductions in the number of total and small LDL particles and increases in average LDL and HDL particle size. The NMR technology used in this study is also used as a diagnostic tool to identify people at greatest risk for developing heart disease. It was developed by LipoMed, Inc., Raleigh, N.C.
"Sadly, almost half of the people who have so-called ‘normal’ cholesterol levels actually go on to develop heart disease," explains Dr. Rosenson. "Millions of them will die from it," he adds. "The good news is that the new technology enables us to more accurately identify individuals at silent but lethal risk, and allows the physicians to select and begin treatments early on."
KEYWORDS: Nuclear magnetic resonance spectroscopy, NMR, cholesterol, lipids, pravastatin
Journal
Atherosclerosis