[Cystatin C as a mortality predictor in a hypertensive population in Extremadura, Spain]

Cystatin C has proven to be a useful parameter to evaluate renal and cardiovascular risk. Nevertheless, there are scanty reports on the utility of this test in the Spanish population. We performed a survey in a group of patients followed up in Primary Care settings.

Prospective follow up of Primary Care attended patients recruited in 2008 and the first half of 2009. The sample included 142 subjects (mean age 64.2±14.6 years, 59.2% men). In all cases, cystatin C was determined and glomerular filtration rate (GFR) was estimated through the Hoek formula. Serum creatinine was also quantified as it was GFR estimated using CKD-EPI equation. The primary objective was a combination of death and major cardiovascular events incidence.

There were 29 events registered (4 of them were deaths) and 9 non cardiovascular deaths. The odds ratio for the primary objective was 5.74 for the last quartile of cystatin C distribution (>1mg/l) (P=.002), while it was 6.44 for cystatin C derived GFR (P=.008) and 5.59 for CKD-EPI estimated GFR (P=.002, Mantel-Haenszel test).

Cystatin C showed a good association with general mortality and the incidence of cardiovascular events in the Spanish population. Nevertheless, it was not better than the observed relationship with GFR, estimated from creatinine.