Hip fracture risk in statin users - a population-based Danish case-control study

Based on animal studies, statins (3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors) have been suggested as potential agents in the treatment of osteoporosis. In some epidemiological studies, statins have been associated with a reduced fracture risk. Our objective was to examine associations between statin treatment and risk of hip fracture in a population-based case-control study. A total of 6660 subjects with hip fracture and 33,274 gender- and age-matched population controls were identified from 1 January 1994 to 31 December 2001 using the Hospital Patient Register in North Jutland County, Denmark, and the Danish Central Personal Registry, respectively. Data on redeemed prescriptions for statins within the last 5 years before the index date were retrieved from a population-based prescription database. We used conditional logistic regression to estimate odds ratios (OR) for hip fracture according to use of statin prescriptions adjusted for potential confounding factors, i.e. gender, other diseases, and use of other drugs known to affect bone metabolism and fracture risk. After adjustment for potential confounders, statin treatment was associated with a reduced risk of hip fracture (OR=0.68; 95% confidence interval: 0.50-0.93) for those who had redeemed more than three prescriptions for a statin drug. We found that risk of hip fracture decreased with the number of statin prescriptions. Stratified analyses on gender and age did not reveal any major differences between men and women or among different age groups on the estimates between use of statins and hip fracture risk. Our findings support an association between statin treatment and a reduced hip fracture risk. However, it is unclear whether this association is causal.