A study of Medicare beneficiaries with atrial fibrillation who were hospitalized between March 1998 and April 1999 throughout the country found that men who were on longterm (defined as >1 yr) warfarin therapy were 63% more likely to suffer an osteoporosis-related fracture of the hip, spine, or wrist.Women on long-term therapy and patients who took the drug for <1 year had no significant increase in risk.
Vitamin K is involved in the activation of bone proteins. Warfarin's inhibition of this activation process because of vitamin K antagonism may explain why patients on long-term therapy face an increased risk of osteoporosis. The study also found that patients who were on beta-blockers or who had high dietary intake of vitamin K and folate had a decreased risk of fractures.
Dr. Garrett is a clinical pharmacist practitioner at Cornerstone Health Care in High Point, NC.
One study linked multiple pregnancies to an increased risk of developing atrial fibrillation later in life, and another investigated the association between premature delivery and cardiovascular disease.
Clinical features with downloadable PDFs