Statins are a type of drug that can help you to lower your blood cholesterol levels. These drugs work by inhibiting HMG CoA reductase, an enzyme that the body uses to create cholesterol. Statin use has also been shown to reduce the risk of heart disease and stroke. While these drugs confer many benefits to users, there are a subset of individuals – believed to be around 20% – who develop statin-induced myopathy, which is characterized by muscle pain, tenderness, and weakness. According to an article in Medical XPress, Israeli researchers recently identified a form of limb-girdle muscular dystrophy (LGMD) caused by HMGCR mutations. These mutations also inhibit HMG CoA reductase. The research team sought to develop a treatment option that could address both HMGCR LGMD and statin myopathy.

In their study, the results of which were published in Proceedings of the National Academy of Sciences (PNAS), the research team began with Methylmevalonolactone, a product normally created from HMG CoA reductase. Next, the researchers synthesized and purified the product, creating mevalonolactone. This drug was later allowed, via Compassionate Use, to be used by a patient with severe HMGCR LGMD. Prior to treatment, this patient struggled with mobility and required the use of a ventilator. After over 1 year of treatment, the patient is now able to breathe without ventilatory support for hours (though she still supplements with ventilatory support) and is better able to move her extremities.

Additional testing in mice with statin myopathy, or who mimicked this condition, found that mevalonolactone also improved muscle function, and reduced pain, in this indication. Although these findings are positive, more research is needed to better understand this treatment and its potential in treating HMGCR LGMD and statin myopathy.

What is Limb-Girdle Muscular Dystrophy (LGMD)?

There are multiple forms of limb-girdle muscular dystrophy caused by gene mutations associated with muscle repair and maintenance. LGMD is considered one of the nine forms of muscular dystrophy; these genetic disorders cause progressive muscle weakness and degeneration. In LGMD, this primarily affects the shoulders, pelvis, thighs, and upper arms. An estimated 1 in every 14,500-123,000 people have LGMD. Symptoms and severity may vary, but potential symptoms may include:

• An abnormal gait
• Scapular winging (shoulderblades that “stick up” from the back)
• Joint stiffness
• Scoliosis or lordosis (abnormal spinal curvature)
• Cardiomyopathy
• Developmental or learning delays (in rare cases)
• Calf muscle overgrowth

Treatments include physical and occupational therapy, mobility aids, and surgery. Right now, no cure exists.