Research published in the journal PLOS ONE suggests that low vitamin D levels are associated with increased risk of developing statin induced myalgia.
Statin induced myalgia (SIM) refers to muscle pain due to taking statins. Around 10-15% of people taking statins experience myopathy (general muscle problems) and/or myalgia.
It’s not clear why taking statins affects some people’s muscles. One thought is that statins cause decreased levels of coenzyme Q10, and in consequence, this may cause myopathy.
Researchers in the past have looked at the vitamin D levels of patients with SIM and compared those with patients on statins without SIM, to see if vitamin D might be involved. The findings have been mixed, with some studies showing SIM patients having lower vitamin D levels and other studies showing no relationship.
In the current study, researchers from The Wright Center for Graduate Medical Education in Pennsylvania wanted to know if there was a longitudinal relationship. They wanted to know if vitamin D levels predicted the likelihood of getting SIM months or years later.
The researchers examined 5,526 consecutive patient records at a primary care practice in Pennsylvania from 2005-2012, 1,160 of which started taking statins during the study. The researchers followed these 1,160 patients for 7 years, or until the patient got SIM.
They wanted to know if vitamin D levels at statin initiation correlated with risk of getting SIM. They divided the patients into quartiles of statin initiation vitamin D levels: less than 10 ng/ml, 11-20 ng/ml, 21-30 ng/ml, and over 31 ng/ml.
Which group was most at risk of getting SIM? Here’s what they found:
- A total of 276 patients developed SIM.
- People over 31 ng/ml had the lowest risk of developing SIM.
- In unadjusted analysis, those with levels less than 10 ng/ml had the greatest risk [HR 1.21 (compared to over 31 ng/l), 95% Cl: 1.07–1.44].
- In unadjusted analysis, those with levels 11-20 ng/ml had the next greatest risk (HR 1.15, 95% Cl: 1.03–1.39).
- In unadjusted analysis, those with levels less than 21-30 ng/ml had the next greatest risk (HR 1.08, 95% Cl: 1.00–1.22).
- In adjusted models, the researchers found similar trends and results.
The researchers concluded,
“Our study shows an association between vitamin D deficiency at statin initiation and subsequent development of SIM.”
There were some limitations in this study. The incidence of SIM was much higher than prior studies, so it’s hard to say if these results apply to the general statin-taking population. Furthermore, it’s important to note that this study was observational, so we can’t say for sure if low vitamin D levels cause SIM.
That being said, this study was an improvement in design in comparison to previous studies, with its prospective longitudinal design. The researchers recommend future clinical trials seeing if vitamin D supplementation can prevent or help treat SIM.