Bisphosphonates and risk of stroke: matched case-control study

Conference: 
SAPC ASM 2015 - Oxford - Evidence and innovation in primary care
Talk Code: 
EP2A.9

The problem

Calcium, vitamin D and bisphosphonates are widely used to prevent osteoporotic fractures but there are concerns that these drugs may be associated with increased cardiovascular risk. For calcium and vitamin D there is evidence of a higher incidence of cardiovascular disease including stroke and there are similar concerns about the cardiovascular safety of bisphosphonates. We aimed to investigate whether there is an association between bisphosphonate use and risk of stroke.

The approach

We used a matched 1:1 case-control design with data from the United Kingdom General Practice Research Database (GPRD). We compared cases, aged 18 years or above, either living or dead, affected by a first stroke during September 2001 to August 2009, with controls, matched for age, sex, calendar time and practice. Outcome measures were unadjusted and adjusted odds ratios and 95% confidence intervals for stroke associated with bisphosphonate treatment prior to the index date. We adjusted for disease groups, cardiovascular risk factors, treatments, GP consultations, home visits and socio-economic deprivation.

Findings

We included 26,784 cases of stroke with an equal number of matched controls. Two thirds of participants were aged 65 years or older and there were similar number of females and males (51.5% and 48.5% respectively). The unadjusted analysis showed an association between bisphosphonates and stroke risk (OR 1.14, 95% CI 1.07-1.22) but there was no relationship between bisphosphonates and risk of stroke in the adjusted analysis (adjusted OR 1.00, 95% CI 0.92-1.09).

Consequences

We found no association between bisphosphonate treatment and risk of stroke. Bisphosphonates may be a safer alternative for prevention of osteoporosis and fractures in people at risk of cardiovascular disease.

Credits

  • Ana Godoy Caballero, Lincoln County Hospital, United Lincolnshire Hospital Trust, Lincoln, UK
  • Zahid Asghar, Lincoln County Hospital, United Lincolnshire Hospital Trust, Lincoln, UK
  • Niroshan Siriwardena, Lincoln County Hospital, United Lincolnshire Hospital Trust, Lincoln, UK
  • Karen Windle, Lincoln County Hospital, United Lincolnshire Hospital Trust, Lincoln, UK
  • Stephen McKay, Lincoln County Hospital, United Lincolnshire Hospital Trust, Lincoln, UK
  • Paul Grassby, Lincoln County Hospital, United Lincolnshire Hospital Trust, Lincoln, UK
  • Jagdish Sharma