Risk factors Related to Rhabdomyolysis in Thai Statin Users: A Case-control Study

Previous studies on statin have revealed that increasing age, renal insufficiency, and concomitant medications were associated with rhabdomyolysis. However, there is a lack of analysis on the magnitude of such association in the Asia-Pacific region. The objectives of this study were to identify risk factors of statin-associated rhabdomyolysis in Thai patients and to evaluate the magnitude of association between the risk factors and rhabdomyolysis. The casecontrol study was carried out at five tertiary-care hospitals in Thailand and patients’ data of 2005-2008 were collected. Data of cases with rhabdomyolysis were extracted from patient’s profiles. For each case, the researchers randomly selected ten controls for making a comparison. Data extracted included demographics, type of statins, dosage, duration, and concomitant medications. No matching of controls to cases was performed in this study and the data collectors were not blinded. Of the 220 patients, the three most commonly used were simvastatin (80.0%), atorvastatin (15.0%), and rosuvastatin (5.0%). A univariable analysis indicated that the most powerful risk factor for rhabdomyolysis was renal disease, odds ratio (OR, 24.00; 95% CI, 6.6885.49). The number of concomitant medications was also associated with significant increased risk of rhabdomyolysis, OR 3.85 (95% CI, 1.40-10.61) and 13.23 (95% CI, 1.54-113.62) for one and two concomitant medications, respectively. In multivariable analysis, the only significant association found was between renal disease and rhabdomyolysis with a Coefficient 3.46 (95% CI, 2.21-4.71). This study reiterates that renal disease plays a key role in precipitating statin-associated rhabdomyolysis. Impaired renal function could lower elimination of statins and concomitant drugs, resulting in drug interactions and rhabdomyolysis. Keyword: statin, rhabdomyolysis, risk factor, drug interaction, renal disease.