Possible Correlation between INR and Serum Calcium

Abstract

Experimental and clinical studies have shown that long term anticoagulation therapy with warfarin can induce vascular calcification which is preventable by vitamin K. Osteoporosis has been shown to be associated with vascular calcification. In the present study, we wanted to see, whether INR (International Normalized Ratio), a measure of prothrombin time, and serum calcium (corrected by albumin) correlate in laboratory data of 94 anticoagulation patients on warfarin therapy. When adjusted on age and sex, there was an inverse correlation between the two variables. Clinical relevance of this observation and explanation of lowered calcium levels in blood parallel to increase in INR-values remain to be studied further.