AIM: The study aimed to explore the prevalence of osteoporosis conditions in Malaysians with chronic warfarin patients using calcaneal quarter of Quantitative Ultrasound (QUS) machine and to investigate whether long-term sodium warfarin therapy that antagonizes vitamin K is affecting the increasing rate of osteoporosis in Penang and to find the risk factors of getting osteoporosis among warfarin users and its non users.

MATERIALS AND METHODS: A case-control study was conducted among 130 patients using warfarin, attending the outpatient clinic at Hospital Pulau Pinang. A convenience sampling method was used to recruit the required sample. Another 140 subjects were selected from the community as a control group (non-users of warfarin).

RESULTS: This study showed that more than three-quarter patients (82%) were at high risk of abnormal BMD. The warfarin users were two times more likely to have a higher osteoporosis risk compared to control group. Moreover, BMD has a negative correlation with age, but has a positive correlation with Body Mass Index (BMI). Patients showed a negative correlation with a higher dose of warfarin intake.