Do diuretics increase risk of backbone fracture after stroke?

The aim of this study was to investigate if diuretic use increases the risk of backbone fracture after stroke. The main finding of the study was that short-term use of diuretics was associated with an increased risk of backbone fracture after stroke.

When people get older, their bones get weaker. This is called osteoporosis. Osteoporosis increases the risk of bone fractures. The most common fracture in patients with osteoporosis is a backbone (vertebrae) fracture. Stroke increases the risk of both osteoporosis and fractures.

High blood pressure (hypertension) is often present with people who have had a stroke. Diuretics are drugs used to remove fluid from the body. Removing fluid from the body, decreases the pressure in the blood vessels and therefore lowers blood pressure. Patients often refer to their diuretic medications as their “water tablet”. There are many different types of diuretics such as thiazides and loop diuretics. These work on different parts of the kidney. Commonly used loop diuretics include Furosemide (Lasix) and Bumetanide (Bumex). Indapamide (Lozol) is a commonly used thiazide diuretic. It is thought that diuretics also have an effect of calcium, the mineral needed for bone. In addition, they may also increase the risk of falls.

It is not known if the use of diuretics is associated with an increased risk of backbone fractures.

4,734 patients who were treated with thiazide diuretics were compared against 4,734 patients who did not use any diuretics within 2 years after a stroke. 2,364 patients who were treated with loop diuretics were compared against 2,364 patients who were not treated with any diuretics within 2 years after a stroke.

Overall, there was no significant difference in backbone fracture risk in patients treated with thiazides and those not treated with any diuretics. However, patients treated with thiazides for a short-term period (less than 90 days) had a 38% increased risk of backbone fracture.

Patients who were treated with loop diuretics had a 45% increased risk of backbone fracture compared to those not treated with diuretics. Patients treated with short-term loop diuretics had a 56% increased risk of backbone fracture. Long-term treatment with either loop of thiazide diuretics did not increase backbone fracture risk.

The authors concluded that short-term treatment with thiazide or loop diuretics within 2 years after a stroke increased the risk of backbone fractures.

Other factors can increase the risk of osteoporosis and fractures, such as alcohol consumption, smoking or diet. These factors were not accounted for in this analysis.