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A new study from Columbia University sheds light on why millions of Americans discontinue their cholesterol-lowering statin medications – a common side effect of muscle pain, weakness, or fatigue. Researchers have identified a mechanism by which certain statins may disrupt muscle function by triggering a calcium leak within muscle cells.
Roughly 40 million adults in the United States take statins to manage cholesterol levels, yet approximately 10% experience muscle-related side effects, leading many to abandon the treatment. “It’s the most common reason patients quit statins, and it’s a very real problem that needs a solution,” stated a leading researcher involved in the study.
The Long-Standing Mystery of Statin Myopathy
Since their introduction in the late 1980s, statins have been remarkably effective in reducing cardiovascular risk. However, the issue of statin-associated muscle symptoms, often referred to as statin myopathy, has remained a significant clinical challenge. While statins primarily work by inhibiting an enzyme crucial for cholesterol production, scientists have long suspected they could also interact with other targets within the body, leading to unintended consequences.
Previous research suggested a link between statins and specific proteins in muscle tissue, but the precise nature of this interaction remained elusive. Now, utilizing cryo-electron microscopy – a cutting-edge imaging technique capable of visualizing structures at the atomic level – the Columbia team has directly observed how statins interact with muscle cells.
Calcium Leakage Disrupts Muscle Function
The research revealed that a commonly prescribed statin, simvastatin, binds to two specific locations on a muscle protein called the ryanodine receptor. This binding action opens a channel within the protein, causing calcium to leak from its normal storage sites into areas of the muscle cell where it doesn’t belong.
According to researchers, this calcium leakage is a potential explanation for the muscle pain and weakness associated with statins. The excess calcium can directly impair muscle fiber function or activate enzymes that contribute to muscle tissue breakdown. “It is unlikely that this explanation applies to everyone who experiences muscular side effects with statins, but even if it explains a small subset, that’s a lot of people we could help if we can resolve the issue,” explained the study’s chair of the Department of Physiology and Cellular Biophysics at the Vagelos College of Physicians and Surgeons.
Toward Safer Cholesterol Management
These findings open new avenues for developing statins with fewer side effects. One strategy involves redesigning statin molecules to maintain their cholesterol-lowering efficacy while preventing binding to the ryanodine receptor. The research team is currently collaborating with chemists to explore this possibility.
Another promising approach focuses on directly addressing the calcium leak. Researchers demonstrated in mice that statin-related calcium leakage could be halted using an experimental drug already under development in the laboratory for other conditions involving abnormal calcium flow. “These drugs are currently being tested in people with rare muscle diseases. If it shows efficacy in those patients, we can test it in statin-induced myopathies,” the researcher noted.
Study Details and Funding
The study, published December 15 in the Journal of Clinical Investigation (“Structural basis for simvastatin-induced skeletal muscle weakness associated with RyR1 T4709M mutation”), involved a collaborative effort from researchers at Columbia University and the University of Rochester. The full author list includes Gunnar Weninger, Haikel Dridi, Steven Reiken, Qi Yuan, Nan Zhao, Linda Groom, Jennifer Leigh, Yang Liu, Carl Tchagou, Jiayi Kang, Alexander Chang, Estefania Luna-Figueroa, Marco C. Miotto, Anetta Wronska, Robert T. Dirksen, and Andrew R. Marks.
Funding for the research was provided by the National Institutes of Health (NIH) through grants R01HL145473, R01DK118240, R01HL142903, R01HL140934, R01NS114570, R01AR070194, R01AR078000, R25HL156002, R25NS076445, P01HL164319, and T32HL120826.
It’s important to note that Andrew Marks holds stock in RyCarma Therapeutics Inc., a company developing compounds targeting the ryanodine receptor, and is a co-inventor on related U.S. patents (US8022058 and US8710045). Additionally, Marks and several co-authors are inventors on a patent application for “STATIN INNOVATION FOR MUSCLE-FRIENDLY CHOLESTEROL MANAGEMENT” (CU24350), filed by Columbia University. These findings represent a significant step toward understanding and mitigating the debilitating side effects that prevent many patients from benefiting from life-saving statin therapy.
