Is Statin Use Associated With Risk of Thyroid Diseases? Results of a Retrospective Cohort Study.

BACKGROUND: Given the ubiquity of statin use and prevalence of thyroid diseases, such as thyroid cancer, hyperthyroidism, and thyroiditis, understanding their association deserves further attention. OBJECTIVE: To examine the association between statin use and thyroid cancer, thyrotoxicosis, goiter, and thyroiditis. METHODS: Using Tricare data, 2 propensity score (PS)-matched cohorts of statin users and nonusers were formed: (1) a PS-matched general cohort (all patients aged 30-85 years) and (2) a PS-matched healthy cohort (excluded patients with cardiovascular diseases or severe comorbidities). Outcomes were thyroid cancer, thyrotoxicosis, goiter, and thyroiditis. Odds ratios (ORs) and 95% CIs of outcomes were estimated using conditional regression analysis. RESULTS: Of 43 438 patients, the PS-matched general cohort matched 6342 statin users to 6342 nonusers. The OR of thyroid cancer was 0.62 (95% CI = 0.39-0.996). There was no significant difference between statin users and nonusers in risk of thyrotoxicosis (OR = 0.88; 95% CI = 0.71-1.09), goiter (OR = 0.9; 95% CI = 0.77-1.03), or thyroiditis (OR = 0.78; 95% CI = 0.53-1.15). In the PS-matched healthy cohort (3351 statin users to 3351 nonusers), there was no difference between statin users and nonusers in any outcome. Limitations of the study include its retrospective observational design and use of administrative codes in outcomes ascertainment. CONCLUSION AND RELEVANCE: This study did not demonstrate any association of statins with harmful effects on thyroid diseases, which offers assurance to clinicians and patients. Furthermore, statin use appears to be associated with a decreased risk of thyroid cancer, but more studies are needed.

Association of Statin Therapy With Risk of Epilepsy in 2 Propensity Score-Matched Cohorts.

BACKGROUND: Studies have suggested that statins may have a neuroprotective effect against epilepsy. However, evidence from rat models and case reports have suggested an opposite effect. Overall data are limited. OBJECTIVE: To examine the association between statin use and epilepsy risk in a general population and in a healthy population (individuals with no severe comorbidities). METHODS: Patients were Tricare beneficiaries from October 2003 to March 2012. Based on patients' characteristics during baseline phase (fiscal year [FY] 2004-2005), 2 propensity score (PS)-matched cohorts of statin users and nonusers were formed: (1) a PS-matched general cohort and (2) a PS-matched healthy cohort. Our outcome was defined using inpatient or outpatient ICD-9 codes for epilepsy during the follow-up phase (FY 2006 to March 2012) in the cohorts of statin users and nonusers. RESULTS: The study included a total of 43 438 patients (13 626 statin users and 29 812 nonusers). The PS-matched general cohort matched 6342 statin users to 6342 nonusers; the odds ratio (OR) of epilepsy in this cohort during follow-up was 0.91; 95% CI = 0.67-1.23. The PS-matched healthy cohort matched 3351 statin users to 3351 nonusers; OR in the PS-matched healthy cohort during follow-up was 1.08; 95% CI = 0.64-1.83. CONCLUSIONS: This study did not demonstrate a significant beneficial or deleterious effect of statin use on risk of being diagnosed with epilepsy. Clinicians should not withhold statins, whenever indicated, in patients with epilepsy.