INTERPRETATION Drug-class effects on interindividual variation in blood pressure can account for differences in effects of antihypertensive drugs on risk of stroke independently of effects on mean SBP .
INTRODUCTION Unexplained differences between classes of antihypertensive drugs in their effectiveness in preventing stroke might be due to class effects on intraindividual variability in blood pressure .
We did a systematic review to assess any such effects in r and omised controlled trials .
Lacidipine and Blood Pressure Variability in Diabetic Hypertensive Patients
The aim of our study was to assess the effects of lacidipine , a long-acting calcium antagonist , on  24-hour average blood pressure , blood pressure variability , and baroreflex sensitivity . In 10 mildly to moderately hypertensive patients with type II diabetes mellitus ( aged 18 to 65 years ) , 24-hour ambulatory blood pressure was continuously monitored noninvasively ( Portapres device ) after a 3-week pretreatment with placebo and a subsequent 4-week once daily lacidipine ( 4 mg ) or placebo treatment ( double-blind crossover design ) . Systolic blood pressure , diastolic blood pressure , and heart rate means were computed each hour for 24 hours ( day and night ) at the end of each treatment period . Similar assessment s were also made for blood pressure and heart rate variability ( st and ard deviation and variation coefficient ) and for 24-hour baroreflex sensitivity , which was quantified ( 1 ) in the time domain by the slope of the spontaneous sequences characterized by progressive increases or reductions of systolic blood pressure and RR interval and ( 2 ) in the frequency domain by the squared ratio of RR interval and systolic blood pressure spectral power ≈0.1 and 0.3 Hz over the 24 hours . Compared with placebo , lacidipine  reduced the 24-hour , daytime , and nighttime systolic and diastolic blood pressure ( P < 0.05 ) with no significant change in heart rate . It also reduced 24-hour , daytime , and nighttime st and ard deviation ( −19.6 % , −14.4 % , and −24.0 % , respectively;P < 0.05 ) and their variation coefficient . The 24-hour average slope of all sequences ( 7.7±1.7 ms/mm Hg ) seen during placebo was significantly increased by lacidipine ( 8.7±1.8 ms/mm Hg , P < 0.01 ) , with a significant increase being obtained also for the 24-hour average & agr ; coefficient at 0.1 Hz ( from 5.7±1.5 to 6.4±1.3 ms/mm Hg , P < 0.01 ) . Thus , in diabetic hypertensive patients  , lacidipine  reduced not only 24-hour blood pressure means but also blood pressure variability . This reduction was accompanied by an improvement of baroreflex sensitivity . Computer analysis of beat-to-beat 24-hour noninvasive blood pressure monitoring may offer valuable information about the effects of antihypertensive drugs on hemodynamic and autonomic parameters in daily life
INTERPRETATION Drug-class effects on interindividual variation in blood pressure can account for differences in effects of antihypertensive drugs on risk of stroke independently of effects on mean SBP .
INTRODUCTION Unexplained differences between classes of antihypertensive drugs in their effectiveness in preventing stroke might be due to class effects on intraindividual variability in blood pressure .
We did a systematic review to assess any such effects in r and omised controlled trials .