**2.1.3 Nephrotic syndrome and venous thromboembolism**

Several studies consider Nephrotic Syndrome as a risk factor for venous thromboembolism. In one of the largest studies, Kayali el al, studied 925,000 patients discharged from hospitals in the United States with the diagnosis of nephrotic syndrome, 0.5% had pulmonary embolism, 6.5% had deep vein thrombosis and less than 0.5% had renal vein thrombosis. The relative risk of pulmonary embolism (in patients with the nephrotic syndrome) was 1.39 and for deep vein thrombosis was 1.72. Among patients aged 18-39 years the relative risk of deep vein thrombosis increases to 6.81 (Kayali, 2008).

Another prospective study of 298 patients with nephrotic syndrome, with a mean follow up of 10±9 years, the annual incidence of venous thromboembolism was 1.02%, over the first 6 months of follow up; the rate of venous thromboembolism was 9.85. In this group of patients, proteinuria and serum albumin levels tended to be related to venous tromboembolism, however, only the predictive value of the ratio of proteinuria to serum albumin was significant but not the estimated glomerular filtration rate.(Bakhtawar, 2008)

For instance, estimated glomerular filtration rate using cystatin C, albuminuria and ratio proteinuria to serum albumin have predictive value for venous thromboembolism in patients with chronic renal disease.
