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Paradoxical effect of age on improvements in pulse pressure during blood pressure lowering
Abstracts / Journal of the American Society of Hypertension 9(4S) (2015) e35–e48 changes resulting in increased vascular stiffness, which may potentially put them at a greater risk of adverse CV events. Keywords: Pulse pressure; Resistant hypertnesion; Gender
P-38 Paradoxical effect of age on improvements in pulse pressure during blood pressure lowering Hemal Bhatt, Mohammed Siddiqui, Stacey Cofield, Brandon George, Allison Fialkowski, Erica Dawson, David Calhoun, Suzanne Oparil, Eric Judd. University of Alabama at Birmingham, Birmingham, AL, United States Resistant hypertension (rHTN) is defined as blood pressure (BP) that remains above goal in spite of using 3 different classes of antihypertensive medications at optimal dosages with one being a diuretic. Pulse pressure (PP, systolic BP - diastolic BP) has been associated with adverse cardiovascular (CV) events. Aging is associated with an increase in PP, but the effect of aging on changes in PP remains during BP lowering is unknown. Adults with rHTN between January 1, 2008 and May 1, 2013 were retrospectively analyzed. Demographics, office BP, comorbidities and medication use were collected at baseline. The office BP was again measured at the last follow-up visit. The 2nd of 2 consecutive manual office BP readings was used. The change in PP was calculated as the baseline PP - follow-up PP. BP measurements were done using standard techniques: allowing patients to sit for 5 minutes, using the appropriate sized cuff, back supported and feet on the floor and measured arm supported at chest level. A total 336 patients were included in the analysis. The mean and median days from baseline visit to the last follow-up was 273 and 56 days, respectively. After adjusting for days of follow-up (p ¼ 0.06), change in PP was associated with baseline PP, such that for every PP one unit higher at baseline, PP decreased by 0.6 mmHg at follow-up (p < 0.0001). After adjusting for systolic BP (Table 1), age was associated with change in PP (p ¼ 0.0122).There was a significant decrease in PP at the follow-up visit across all age groups. There was a greater change (decrease) in PP with decreasing age, with the greatest change among patients 41-50 years; however, the trend was absent in patients <40 years old. This observation was consistent even after adjusting for SBP. The decrease in PP among individuals with 51-60 years and 41-50 years (14.1 and 15 mm Hg, respectively) was significantly greater than those 71 years (4.7 mmHg). The blunted change in PP in older individuals ( 71 years) seems consistent with increased vascular stiffness. Fixed vascular stiffness in older individuals may render their vessels resistant to improvements in PP during BP lowering. The blunted PP among younger subjects (<40 years) is surprising and suggests that antihypertensive therapy is less effective in reducing a marker of vascular stiffness in young individuals with resistant hypertension. Keywords: Resistant Hypertension; Pulse pressure; Aging
P-39 Nighttime ambulatory blood pressure in periods defined by self report, fixed times and actigraphy John N. Booth, III,3 Paul Muntner,3 Marwah Abdalla,1 Keith Diaz,1 Anthony Viera,4 Kristi Reynolds,2 Joseph E. Schwartz,1 Daichi Shimbo.1 1 Columbia University, NY, United States; 2Kaiser Permanente Southern
e37
CA, CA, United States; 3University of AL - Birmingham, AL, United States; University of NC, NC, United States
4
The nighttime period on 24-hour ambulatory blood pressure monitoring (ABPM) can be defined using three approaches: self-report (SR), a fixed time period or actigraphy. Nighttime and daytime ambulatory blood pressure (ABP) and related measures (e.g., non-dipping status) may depend on how the nighttime period is defined. This study compared mean ABP and nighttime hypertension (HT), daytime HT and non-dipping status using each approach to define the nighttime period (i.e., SR, fixed period, actigraphy). We used data from the Improving the Detection of Hypertension Study, a community based investigation of normotensive and untreated hypertensive adults from northern Manhattan without overt cardiovascular disease (CVD) and renal failure. The 24-hour ABPM and actigraphy were simultaneously performed. Participants’ nighttime and daytime periods were defined by SR from a sleep diary, fixed periods (nighttime 12 am - 6 pm, daytime 10 am - 8 pm) and wrist actigraphy. For each approach, mean nighttime and daytime ABP were defined by averaging the ABP readings within each period. Nighttime HT was defined as mean nighttime systolic/diastolic blood pressure (BP) 120/70 mmHg. Daytime HT was defined as mean daytime systolic/diastolic BP 135/85 mmHg. Nondipping status was defined as night-day BP ratio 0.90. Analyses included 330 participants (mean age SD 40.5 13.0 years, 41.8% male). SR and actigraphy sleep onset occurred after 12 am in 43.6% and 55.5% of participants, respectively, and awakening occurred after 10 am in 6.4% and 4.8% of participants, respectively. In Bland Altman plots comparing SR vs fixed periods, SR vs actigraphy and fixed periods vs actigraphy, the mean difference (95% CI; i.e., limits of agreement) in nighttime systolic ABP was -0.5 (-6.6, 5.6), 0.9 (-3.6, 5.4) and 1.4 (-5.6, 8.5) mmHg, respectively, and diastolic ABP was -0.4 (-5.5, 4.6), 0.7 (-3.5, 5.0) and 1.2 (-5.0, 7.3) mmHg, respectively. The agreement in nighttime HT, daytime HT and non-dipping status was good for the approaches used with the greatest agreement for SR vs actigraphy (Table). In conclusion, SR vs actigraphy had the narrowest limits of agreement for mean nighttime systolic and diastolic ABP and the strongest agreement for nighttime HT, daytime HT and non-dipping status. Future studies should compare the predictive value of nighttime ABP for CVD events using different approaches to define the nighttime period. Keywords: ambulatory blood pressure monitoring; measurement of diurnal periods; self-report, fixed time period, actigraphy
P-38 Paradoxical effect of age on improvements in pulse pressure during blood pressure lowering Hemal Bhatt, Mohammed Siddiqui, Stacey Cofield, Brandon George, Allison Fialkowski, Erica Dawson, David Calhoun, Suzanne Oparil, Eric Judd. University of Alabama at Birmingham, Birmingham, AL, United States Resistant hypertension (rHTN) is defined as blood pressure (BP) that remains above goal in spite of using 3 different classes of antihypertensive medications at optimal dosages with one being a diuretic. Pulse pressure (PP, systolic BP - diastolic BP) has been associated with adverse cardiovascular (CV) events. Aging is associated with an increase in PP, but the effect of aging on changes in PP remains during BP lowering is unknown. Adults with rHTN between January 1, 2008 and May 1, 2013 were retrospectively analyzed. Demographics, office BP, comorbidities and medication use were collected at baseline. The office BP was again measured at the last follow-up visit. The 2nd of 2 consecutive manual office BP readings was used. The change in PP was calculated as the baseline PP - follow-up PP. BP measurements were done using standard techniques: allowing patients to sit for 5 minutes, using the appropriate sized cuff, back supported and feet on the floor and measured arm supported at chest level. A total 336 patients were included in the analysis. The mean and median days from baseline visit to the last follow-up was 273 and 56 days, respectively. After adjusting for days of follow-up (p ¼ 0.06), change in PP was associated with baseline PP, such that for every PP one unit higher at baseline, PP decreased by 0.6 mmHg at follow-up (p < 0.0001). After adjusting for systolic BP (Table 1), age was associated with change in PP (p ¼ 0.0122).There was a significant decrease in PP at the follow-up visit across all age groups. There was a greater change (decrease) in PP with decreasing age, with the greatest change among patients 41-50 years; however, the trend was absent in patients <40 years old. This observation was consistent even after adjusting for SBP. The decrease in PP among individuals with 51-60 years and 41-50 years (14.1 and 15 mm Hg, respectively) was significantly greater than those 71 years (4.7 mmHg). The blunted change in PP in older individuals ( 71 years) seems consistent with increased vascular stiffness. Fixed vascular stiffness in older individuals may render their vessels resistant to improvements in PP during BP lowering. The blunted PP among younger subjects (<40 years) is surprising and suggests that antihypertensive therapy is less effective in reducing a marker of vascular stiffness in young individuals with resistant hypertension. Keywords: Resistant Hypertension; Pulse pressure; Aging
P-39 Nighttime ambulatory blood pressure in periods defined by self report, fixed times and actigraphy John N. Booth, III,3 Paul Muntner,3 Marwah Abdalla,1 Keith Diaz,1 Anthony Viera,4 Kristi Reynolds,2 Joseph E. Schwartz,1 Daichi Shimbo.1 1 Columbia University, NY, United States; 2Kaiser Permanente Southern
e37
CA, CA, United States; 3University of AL - Birmingham, AL, United States; University of NC, NC, United States
4
The nighttime period on 24-hour ambulatory blood pressure monitoring (ABPM) can be defined using three approaches: self-report (SR), a fixed time period or actigraphy. Nighttime and daytime ambulatory blood pressure (ABP) and related measures (e.g., non-dipping status) may depend on how the nighttime period is defined. This study compared mean ABP and nighttime hypertension (HT), daytime HT and non-dipping status using each approach to define the nighttime period (i.e., SR, fixed period, actigraphy). We used data from the Improving the Detection of Hypertension Study, a community based investigation of normotensive and untreated hypertensive adults from northern Manhattan without overt cardiovascular disease (CVD) and renal failure. The 24-hour ABPM and actigraphy were simultaneously performed. Participants’ nighttime and daytime periods were defined by SR from a sleep diary, fixed periods (nighttime 12 am - 6 pm, daytime 10 am - 8 pm) and wrist actigraphy. For each approach, mean nighttime and daytime ABP were defined by averaging the ABP readings within each period. Nighttime HT was defined as mean nighttime systolic/diastolic blood pressure (BP) 120/70 mmHg. Daytime HT was defined as mean daytime systolic/diastolic BP 135/85 mmHg. Nondipping status was defined as night-day BP ratio 0.90. Analyses included 330 participants (mean age SD 40.5 13.0 years, 41.8% male). SR and actigraphy sleep onset occurred after 12 am in 43.6% and 55.5% of participants, respectively, and awakening occurred after 10 am in 6.4% and 4.8% of participants, respectively. In Bland Altman plots comparing SR vs fixed periods, SR vs actigraphy and fixed periods vs actigraphy, the mean difference (95% CI; i.e., limits of agreement) in nighttime systolic ABP was -0.5 (-6.6, 5.6), 0.9 (-3.6, 5.4) and 1.4 (-5.6, 8.5) mmHg, respectively, and diastolic ABP was -0.4 (-5.5, 4.6), 0.7 (-3.5, 5.0) and 1.2 (-5.0, 7.3) mmHg, respectively. The agreement in nighttime HT, daytime HT and non-dipping status was good for the approaches used with the greatest agreement for SR vs actigraphy (Table). In conclusion, SR vs actigraphy had the narrowest limits of agreement for mean nighttime systolic and diastolic ABP and the strongest agreement for nighttime HT, daytime HT and non-dipping status. Future studies should compare the predictive value of nighttime ABP for CVD events using different approaches to define the nighttime period. Keywords: ambulatory blood pressure monitoring; measurement of diurnal periods; self-report, fixed time period, actigraphy