NT-proBNP elevations during BP treatment a red flag for kidney function decline

Higher baseline and 1-year increases in N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels among individuals receiving blood pressure (BP)-lowering medications are associated with subsequent declines in estimated glomerular filtration rate (eGFR), according to a study.

For the study, researchers used data from 8,005 SPRINT* participants (mean age 68 years, 36 percent women, mean baseline eGFR 74 ml/min/1.73m) who had available NT-proBNP measurements at baseline (median 86 pg/mL) and at 1 year (median 82 pg/mL). The 1-year change in NT-proBNP levels was categorized as follows: ≥25-percent decrease, ≥25-percent increase, and <25-percent change (stable).

Results showed that compared with stable 1-year NT-proBNP levels, a ≥25-percent decrease in NT-proBNP correlated with a slower decline in eGFR among participants with chronic kidney disease (CKD; adjusted difference, 1.09 percent per year, 95 percent confidence interval [CI], 0.35–1.83) and those without CKD (adjusted difference, 0.51 percent per year, 95 percent CI, 0.21–0.81).

Conversely, a ≥25-percent increase in NT-proBNP was associated with a faster decline in eGFR (adjusted difference, –1.04 percent per year, 95 percent CI, –1.72 to –0.36) and an increased likelihood of a ≥30-percent decline in eGFR (adjusted odds ratio, 1.44, 95 percent CI, 1.06–1.96) among participants with CKD. These associations were not observed to be stronger among participants without CKD.

The findings were consistent in the treatment arms in SPRINT.

Further studies are needed to determine if dynamic NT-proBNP may be useful in monitoring kidney risk during hypertension treatment, according to the researchers.

*Systolic Blood Pressure Intervention Trial