Overweight and obese middle-aged women are more likely to develop potentially fatal blood clots within leg veins than their normal weight counterparts, says a study.


Researchers from Otago and Oxford universities linked questionnaire data from a study of more than one million women in the UK with their hospital admission and death records to examine the risk of venous thromboembolism (VTE) among them -- both without recent surgery and in the first 12 weeks following an inpatient surgery (where the patient remained in hospital overnight or longer after the surgery was completed).

VTE is a relatively rare but potentially life-threatening condition involving blood clots in the legs (deep vein thrombosis or DVT), which sometimes break off and travel to the lungs (pulmonary embolism), the journal Circulation reports.

Lianne Parkin, who teaches preventive and social medicine at Otago and led the study, says the research followed up these women for an average of six years. Their average age at the time of enrollment was 56 years, according to a Otago University statement.

Parkin says the findings show that both overweight and obese women are generally at higher risk of VTE compared to the women of a normal weight, with their risk increasing progressively with increasing BMI (body mass index) and rising sharply following surgery.

"Surgery is known to increase the risk of VTE and our research shows that the risk of post-operative VTE is higher in the women who are overweight or obese than it is in the women who have a healthy weight."

In the 12 weeks following inpatient surgery, the researchers calculated that 4.8 in 1,000 women with a healthy BMI (less than 25) were hospitalised or died from VTE, compared to 7.0 in 1,000 with overweight or obesity issues.