Diuretic initiation and the acute risk of hip fracture

Abstract

Summary: We found the risk of hip fracture was transiently elevated around twofold shortly after initiation of a loop or thiazide diuretic drug in a case-crossover and case-control study. No statistical association was found following the initiation of a comparator medication: ACE inhibitors. Awareness of these short-term risks may reduce hip fractures.

Introduction: Little is known about the acute effects of initiating a diuretic drug on risk of fracture. We evaluated the relationship between initiating a diuretic drug and the occurrence of hip fracture.

Methods: The study sample included 2,118,793 persons aged ≥50 years enrolled in The Health Improvement Network (THIN) between 1986 and 2010. The effect of a new start of a diuretic drug or comparator medication (ACE inhibitor) on risk of hip fracture was assessed using a case-crossover and case-control study during the 1-7, 8-14, 15-21, and 22-28 days following drug initiation.

Results: Included were 28,703 individuals with an incident hip fracture over a mean of 7.9 years follow-up. In the case-crossover study, the risk of experiencing a hip fracture was increased during the first 7 days following loop diuretic drug initiation (OR = 1.8; 95 % CI, 1.2, 2.7). The elevated risk did not continue during the 8-14, 15-21, or 22-28 days following drug initiation. For thiazide diuretics, the risk of hip fracture was elevated 8-14 days after drug initiation (OR = 2.2; 95 % CI, 1.2, 3.9). No such association was observed in the 1-7, 15-21, or 22-28 days following thiazide drug initiation. ACE inhibitor initiation was not associated with a statistically significant increased risk of hip fracture. Similar results were observed using a case-control study.

Conclusions: The risk of hip fracture was transiently elevated around twofold shortly after the new start of a loop or thiazide diuretic drug. Awareness of these short-term risks may reduce hip fractures and other injurious falls in vulnerable adults.

Figure 1

Diagram of the case-crossover study design used to determine the effect of diuretic drug initiation on the acute risk of hip fracture.

Figure 2

Association between diuretic or ACE-I initiation and the acute risk of hip fracture in a case-crossover study of 28,703 persons from The Health Improvement Network with hip fracture.