HMG-CoA Reductase Inhibitors (statins) might Cause High Elevations of Creatine Phosphokinase (CK) in Patients with Unnoticed Hypothyroidism

Abstract

Serious side effects of statins, including severe myopathy and rhabdomyolysis, are rare but important in general practice. Hypothyroidism can cause secondary hypercholesterolemia and myopathy. There have been few reports on the risk of statins in patient with unnoticed hypothyroidism. We analyzed the characteristics of 77 patients with primary hypothyroidism in our hospital. Nine patients (11%) accidentally received statins in the treatment of hypercholesterolemia without diagnosis of hypothyroidism. In such patients, free T4 (FT4) levels were lower, and those of LDH, CK were higher than those in patients not receiving statins. In patients accidentally receiving statins, an inverse correlation between CK and FT4 could not be shown (which was recognized in patients not receiving them). Even after FT4 levels were matched, levels of CK were still higher in the patients accidentally receiving statins. Patients with high CK levels over 1000 U/L were 5 times more frequent (56%) in patients accidentally receiving statins than in those not receiving statins (11%). The present study confirms that statins enhances levels of CK in patients with hypothyroidism. We must not begin and continue to use these drugs without checking the possibility of hypothyroidism.

Rhabdomyolysis in the Setting of Induced Hypothyroidism and Statin Therapy: A Case Report

“…Coexistent hypothyroidism and statin therapy may increase the risk of myopathy and rhabdomyolysis [11]. Several cases of hypothyroid patients taking statin therapy and resulting in rhabdomyolysis have been described [1,4,11].…”

“…Several cases of hypothyroid patients taking statin therapy and resulting in rhabdomyolysis have been described [1,4,11]. In addition to these scenarios, a PubMed literature search identified 2 cases of statin-induced myopathy occurring in the setting of induced hypothyroidism.…”

“…Similarly, potential side effects of statin therapy include muscle pain and CK elevation, but myositis and rhabdomyolysis are also rare in the absence of medication interactions adversely affecting CP450 metabolism of statins [8,9,10]. The coexistence of statin therapy and hypothyroid states may increase the risk of myopathy [11]. We describe a case of significant myositis and rhabdomyolysis likely attributed to thyroid hormone withdrawal in anticipation of adjuvant radioiodine ( 131 I) therapy in a patient with well-differentiated thyroid cancer.…”

The Effect of L–Thyroxine on Metabolic Parameters in Newly Diagnosed Primary Hypothyroidism

“…Statin therapy may substantially increase levels of CK. A study examined the effects of accidentally starting statin therapy in patients with undiagnosed hypothyroidism (n=9) [26]. These patients had significantly higher CK levels (1095 U/L) compared with untreated hypothyroid patients matched for free T4 levels (n=18; CK=395; p<0.05) [27].…”

“…Mild thyroid hormone deficiency per se is responsible for reversible endothelial dysfunction and reduced nitric oxide availability, which act as promoters of atherosclerosis [28]. Accordingly, Mizuma et al recently described the presence of an iodothyronine deiodinase in human Vascular Smooth Muscle (VSM) cells [29].…”