Preliminary research suggests that higher than normal levels of the protein albumin in urine is associated with an increased risk for blood clots in the deep veins of the legs or lungs (venous thromboembolism; VTE), according to a study in the May 6 issue of JAMA, the Journal of the American Medical Association.
The overall incidence of VTE in developed countries is about 0.15 percent per year, varying from less than 0.005 percent in individuals younger than 15 years to as high as 0.5 percent at 80 years of age. Known risk factors for VTE include stasis (a slowing of the normal flow) of the blood and changes in the composition of the blood. However, in as many as 50 percent of VTE cases, none of the known risk factors are present, according to background information in the article.
Microalbuminuria (albumin in urine; 30-300 mg per 24-hour urine collection) is associated with changes in the levels of several coagulation proteins. The effect of coagulation disorders is more evident in the development of VTE than of arterial thromboembolism (formation of a blood clot in the arterial system). "Hence, in theory, a link between microalbuminuria and VTE is likely; however, research addressing this issue has yet to be conducted," the authors write.
Bakhtawar K. Mahmoodi, B.Sc., of the University Medical Centre Groningen, the Netherlands, and colleagues conducted a study to assess whether microalbuminuria is associated with VTE. The ongoing, community-based study, started in 1997, includes all inhabitants of Groningen, the Netherlands, (age 28 through 75 years [n = 85,421]) who were sent a postal questionnaire and a vial to collect a urine sample for measurement of urinary albumin concentration. Of those who responded (40,856), a group (8,592) including more participants with higher levels of urinary albumin concentration completed screening at an outpatient clinic. Screening data were collected on urinary albumin excretion (UAE) and risk factors for cardiovascular and kidney disease.