[Analysis of heart rate as a risk factor associated with the progression of chronic renal failure]

An increased heart rate is associated with an increased risk of cardiovascular and non-cardiovascular death. However, the possible relationship between heart rate and the rate of progression of renal disease has not been assessed so far.

Twenty-four-hour ambulatory blood pressure and heart rate recordings at baseline conditions were obtained in 24 patients with non-diabetic chronic renal failure and hypertension. The rate of progression of renal disease was estimated on the basis of the slope of the reciprocal of serum creatinine concentration against time.

After a mean follow-up of 38 months, the rate of progression of renal failure was 0.004 (0.039) dL/mg/month. Progression of renal disease showed no correlation with baseline ambulatory systolic or diastolic blood pressures, and did not differ between dipper and non-dipper patients. Twenty-four-hour (r = 0.40, p = 0.05) and day-time (r = 0.534, p = 0.007) heart rates showed a relationship with the progression of renal failure. Proteinuria displayed a correlation with night-time heart rate (r = 0.405, p = 0.05) but not with the progression of renal failure.

Baseline ambulatory heart rate, especially day-time heart rate, is associated with the decline of renal function in non-diabetic patients with chronic renal failure, suggesting that heart rate is a risk factor (or marker) for renal disease progression. Prospective controlled studies with a larger sample of patients are needed to confirm these findings and to investigate the possible mechanisms involved in this association.