Beat-to-Beat, Reading-to-Reading, and Day-to-Day Blood Pressure Variability in Relation to Organ Damage in Untreated Chinese

Abstract

Abstract-Whether target organ damage is associated with blood pressure (BP) variability independent of level remains debated. We assessed these associations from 10-minute beat-to-beat, 24-hour ambulatory, and 7-day home BP recordings in 256 untreated subjects referred to a hypertension clinic. BP variability indices were variability independent of the mean, maximum-minimum difference, and average real variability. Effect sizes (standardized β) were computed using multivariable regression models. In beat-to-beat recordings, left ventricular mass index (n=128) was not (P≥0.18) associated with systolic BP but increased with all 3 systolic variability indices (+2.97-3.53 g/m 2 ; P<0.04); the urinary albumin-to-creatinine ratio increased (P≤0.03) with systolic BP (+1.14-1.17 mg/mmol) and maximum-minimum difference (+1.18 mg/mmol); and pulse wave velocity increased with systolic BP (+0.69 m/s; P<0.001). In 24-hour recordings, all 3 indices of organ damage increased (P<0.03) with systolic BP, whereas the associations with BP variability were nonsignificant (P≥0.15) except for increases in pulse wave velocity (P<0.05) with variability independent of the mean (+0.16 m/s) and maximum-minimum difference (+0.17 m/s). In home recordings, the urinary albumin-to-creatinine ratio (+1.27-1.30 mg/mmol) and pulse wave velocity (+0.36-0.40 m/s) increased (P<0.05) with systolic BP, whereas all associations of target organ damage with the variability indices were nonsignificant (P≥0.07). In conclusion, while accounting for BP level, associations of target organ damage with BP variability were readily detectable in beat-to-beat recordings, least noticeable in home recordings, with 24-hour ambulatory monitoring being informative only for pulse Assessment of Organ DamageAs described in detail elsewhere, 16 LVMI by echocardiography (n=128), the urinary albumin-to-creatinine ratio (n=256), and aortic PWV (n=255) were determined as measures of organ damage. For the details of the organ damage assessment and other measurements, including body mass index, serum cholesterol, plasma glucose, and questionnaire survey on smoking and drinking habits, see Expanded Methods in the online-only Data Supplement. Statistical AnalysisFor database management and statistical analysis, we used the Statistical Analysis System software, version 9.3 (SAS Institute, Cary, NC). We limited our main analyses to systolic BP because systolic BP is the main driver of risk 17 and because we recently demonstrated in the same patient cohort that systolic BP was the main determinant of target organ damage irrespective of age. 16 Henceforth, in our article unless otherwise specified, BP refers to systolic BP. We assessed BP variability from the variability independent of the mean (VIM), 15 the difference between maximum and minimum BP (MMD), and average real variability (ARV).10,14 For the details of the computation of these variability indices, see Expanded Methods in the online-only Data Supplement.To study the association between organ damage and BP level and variabi...

Diurnal Blood Pressure Rhythmicity in Relation to Environmental and Genetic Cues in Untreated Referred Patients

“…As described elsewhere, 24,25 we recruited consecutive patients referred for ambulatory BP monitoring to the Hypertension Outpatient Clinic of Ruijin Hospital, Shanghai, China. We adhered to the principles of the Declaration of Helsinki.…”

“…We programmed validated 27 oscillometric SpaceLabs 90217 monitors (SpaceLabs Inc, Redmond, WA) to obtain BP readings at 20-minute intervals during daytime (6 am-10 pm) and at 30-minute intervals during nighttime (10 pm-6 am). 24,25 For analysis, we defined daytime and nighttime as the intervals ranging from 8 am to 6 pm and from 11 pm to 5 am, respectively. For definitions of the night-to-day BP ratio, morning BP surge, ambulatory hypertension, masked, and whitecoat hypertension, see Expanded Methods in the online-only Data Supplement.…”

Long-Term Blood Pressure Variability, New-Onset Diabetes Mellitus, and New-Onset Chronic Kidney Disease in the Japanese General Population

“…[4][5][6][7][8][9][10][11]17 ARV is the average absolute difference between successive BP measurements, and in contrast with SD and CV, it takes the order of the BP measurements into account. 17 Here, we only report BPV using SD and ARV because CV and MMD are strongly correlated with SD (r=0.97-0.99; both P<0.001; Table S1).…”

“…[1][2][3] In addition to average BP values, BP variability (BPV) may be associated with CKD. [4][5][6][7][8][9] BPV consists of shortterm BPV (eg, beat-to-beat and within 24 hour) and long-term BPV (eg, day-by-day and visit-to-visit BPV). 10,11 The implications of long-term BPV are less defined, particularly its effects on kidney.…”

Relationship Between Within-Visit Blood Pressure Variability and Kidney Function in Patients with Arterial Hypertension

“…explored the relationship between short-term BPV/withinvisit BPV and markers of early renal damage, with conflicting results. (10,(14)(15)(16)(17)(18)(19) It could be hypothesized that an enhanced withinvisit BPV in patients with early renal abnormalities may help to explain in part their increased CV risk.…”