[Ambulatory blood pressure monitoring in hypertensive CAPD patients]

The periodic structure of 24-hour blood pressure variation(circadian rhythm of blood pressure by ambulatory blood pressure monitoring(ABPM) in hypertensive CAPD patients was investigated by a new method of analysis based upon the maximum entropy method(MEM). In addition, this method allows the adequacy of antihypertensive therapies to be evaluated in such patients. The results were as follows; 1) The frequency of non-dipper type hypertension was 88%(36/41 cases), and the remaining 12% (5/41) were dipper type hypertension patients. The rise in morning blood pressure(morning surge: MS) was noted in 64% of the former. 2) Night time systolic blood pressure(182 +/- 22 mmHg, n = 36) was higher in patients with non-dipper type hypertension than in those with the dipper type(151 +/- 17 mmHg, n = 5, p < 0.01). 3) The standardized level of systolic blood pressure(SLSBP) calculated by MEM analysis in patients with non-dipper type hypertension(177 +/- 7 mmHg) was comparable with that in those with dipper type hypertension(168 +/- 13 mmHg, ns). 4) Treatment with long-acting Ca antagonist alone significantly reduced both SLSBP and the area over the SLSBP from 188 +/- 18 mmHg to 160 +/- 7 mmHg(p < 0.01, n = 8), and area over the SLSBP from 2,735 +/- 340 mmHg.hr to 1,945 +/- 298 mmHg.hr(p < 0.01, n = 8). 5) In addition to long-acting Ca antagonist, administration of alpha 1-blocker given at bed time was significantly efficacious in reducing the rise in morning blood pressure, MS. The present study using MEM analysis of ABPM suggests that the blood pressure profile of hypertensive CAPD patients is characterized by a non-dipper type dominance and a frequent morning surge. Furthermore, the combined therapy with long-acting Ca antagonist and alpha 1-blocker was substantially effective both in reducing the overall blood pressure level, and in inhibiting the MS. This combined antihypertensive therapy may be potentially useful to prevent CAPD patients from the future development of cardiovascular complications.