Which Came First — Kidney Dysfunction or Hypertension?

Indirect experimental evidence suggests that essential hypertension can be preceded by subtle kidney dysfunction in some cases. To explore this theory, investigators studied 2767 adults (middle-aged or older) without hypertension, cardiovascular disease, or kidney disease in a prospective study (median follow-up, 3 years). Specifically, patients with low glomerular filtration rates and patients with microalbuminuria were excluded.

Twenty percent of participants developed hypertension. In analyses adjusted for multiple potential risk factors, higher cystatin C levels (a marker of reduced kidney function) were associated with a significantly higher hypertension; those in the highest quartile of cystatin C levels had a 31% higher risk than did …