[Significant negative correlation between fasting plasma insulin and ambulatory blood pressure in patients on chronic...

Positive correlation between blood pressure and insulin is well established in patients with essential hypertension. The aim of the present study was to examine the relationship between fasting plasma insulin level and ambulatory blood pressure (ABPM) in patients with chronic renal failure. The study group consisted of 20 patients (11 females, 9 males, mean age 39 +/- 12 years) on chronic haemodialysis (mean 2.5 years). Fasting plasma insulin (FPI) was measured by radioimmunoassay. The patients were investigated before and after haemodialysis. FPI significantly increased after haemodialysis from 18.4 +/- 12.0 to 40.1 +/- 31.9 mIU/l (p < 0.01), while creatinine concentration decreased from 1158 +/- 130 to 910 +/- 159 mumol/l (p < 0.001). Night-time systolic blood pressure (SBP) was significantly lower during the day of haemodialysis (141.9 +/- 19.6 mmHg vs. 136 +/- 27.7 mmHg, p < 0.05). 24-hour and daytime SBP was nonsignificantly lower after haemodialysis. 24-hour diastolic blood pressure (DBP) was significantly lower during the day of haemodialysis (92.9 +/- 12.5 mmHg vs. 87.3 +/- 14.3 mmHg, p < 0.05), as well as daytime (94.9 +/- 12.1 mmHg vs. 88.8 +/- 14.6 p < 0.05) and night-time DBP (88.9 +/- 16.0 mmHg vs. 83.8 +/- 17.4 mmHg p < 0.05). FPI was found to be significantly negatively correlated with 24-hour, daytime and night-time SBP on the day of haemodialysis (r = -0.63, p < 0.005; r = 0.64, (p < 0.005 and r = -0.54, p < 0.05, respectively). The significant negative correlation between FPI and 24-hour SBP suggests that insulin could reveal its hypotensive effect after the haemodialysis.