Adjustment For Blood Pressure Levels Research Articles

Abstract 13701: The Lumen Diameter Enlargement of the Carotid Arteries Increased the Risk of Stroke Incidence in a Japanese Urban Population: The Suita Study

Introduction: We aimed to examine the impact of increased LD of common carotid arteries (CCA), external carotid arteries (ECA), and internal carotid arteries (ICA) on the risk of incident stroke in a general population. Methods: We studied 3,356 Japanese men and women without cardiovascular disease whose CCA, ECA, and ICA were measured by carotid ultrasonography on both sides at baseline (October 2001 to March 2005). We confirmed the near and far walls intima-media interfaces by Doppler and calculated the lumen diameter as the distance between the intima-to-lumen interface of the near-wall to the lumen-to-intima interface of the far wall. The Cox proportional hazard model was used to calculate the multivariable-adjusted hazard ratios (HRs) with 95% confidence intervals (CIs) of stroke incidence according to the CCA, ECA, and ICA LD. Results: During 30,818 person-years of follow-up, we observed 105 incident stroke cases. The higher CCA and ECA LD were associated with increased risks of incident stroke. The associations were attenuated by additional adjustment for blood pressure levels and antihypertensive drugs use, but remained statistically significant. Further adjustment of other traditional cardiovascular risk factors and carotid plaque did not alter the association materially; the multivariable-adjusted HR per standard deviation increase of CCA LD was 1.30 (95% CI, 1.05 to 1.61). Compared with participants in the first quartile (< 4.8 mm) of ECA LD, the multivariable-adjusted HRs of incident stroke were 1.71 (95% CI, 0.86 to 3.38) for those in the second quartile (4.8 - 5.3 mm), 2.18 (95% CI, 1.13 to 4.23) for the third quartile (5.4 - 6.0 mm), and 1.62 (95% CI, 0.79 to 3.29) for the fourth quartile (≥ 6.0 mm) of ECA LD. Such associations were not observed for ICA LD. Conclusions: In addition to the traditional risk factors and carotid plaque, CCA and ECA LD can improve risk reclassification of incident stroke in a general urban population.

Serum Urate Trajectory in Young Adulthood and Incident Cardiovascular Disease Events by Middle Age: CARDIA Study.

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Impaired baroreflex sensitivity and the risks of new-onset ambulatory hypertension, in an elderly population-based study

Impairment of the autonomic nervous system activity may be involved in the development of hypertension. Yet the prognostic values of heart rate variability and baroreflex sensitivity in the risk of new-onset ambulatory hypertension have not been investigated. We sought to assess the relationship between heart rate variability and baroreflex sensitivity parameters and ambulatory hypertension in a community-dwelling elderly cohort. Normotensive subjects were selected from the PROOF study cohort, including 1011 subjects aged 65 years at baseline. The autonomic nervous system activity was assessed through 24-hour heart rate variability and 15-minute spontaneous baroreflex sensitivity at baseline. Incident hypertension was defined with the 24-hour, day-time and night-time ambulatory blood pressure measurements and antihypertensive treatment use, at two-years of follow-up. At baseline, 13.7% of subjects developed day-time hypertension, 18.2% developed night-time hypertension and 13.6% developed 24-hour hypertension. Reduced baroreflex sensitivity at baseline was associated with onset of hypertension after adjustment for blood pressure level, C-reactive protein levels and depression score (OR = 0.45 [0.23-0.86]). Indices of heart rate variability were not associated with hypertension onset. Baroreflex sensitivity may represent an intermediate goal for prevention of ambulatory hypertension at early stage.

Office blood pressure variability as a predictor of acute myocardial infarction in elderly patients receiving antihypertensive therapy

Larger variability of office blood pressure (BP) was reportedly associated with a higher risk of stroke or mortality from all causes. In the present study, we focused on the relationship of variability of office BP and occurrence of acute myocardial infarction (MI). We registered 139 patients receiving antihypertensive therapy for more than 1 year who experienced first-ever episode of MI at the age of 60 years or over. At least two sex- and age-matched (+/- 5 years) control patients were registered for every MI patient. Average systolic and diastolic BP during the 12-month period prior to the occurrence of MI, or the time of registration in the case of control patients, was similar in both patient groups. The office BP variability was evaluated by calculating the variation coefficient (VC) of BP. VC of diastolic BP was significantly higher in the MI patients (10.0 +/- 4.0%) compared with the control patients (8.8 +/- 3.4%). VC of systolic BP was not different between the MI and the control patients. Multiple logistic analysis revealed the relationship of the VC for office diastolic BP to the occurrence of MI was significant after adjustment for BP level, age, gender, body mass index, serum total cholesterol concentrations, diabetes mellitus, and current smoking. In conclusion, larger long-term variability of office diastolic BP during antihypertensive therapy is a predictor of MI.

Office blood pressure variability as a predictor of brain infarction in elderly hypertensive patients.

Large 24-h blood pressure (BP) variability and an excessive drop in BP during nighttime are associated with a higher risk of cardiovascular events. Data are lacking regarding the prognostic significance of variability in BP measured during office visits. We analyzed the relationship between office BP variability and the risk of brain infarction in elderly patients receiving antihypertensive therapy. Patients who experienced their first-ever stroke at the age of 60 years or over were registered in the study. At least 2 sex- and age-matched control patients were registered for each case patient. Office BP at each clinic visit and known cardiovascular risk factors were recorded. The BP variability was defined as the variation coefficient (VC) of office BP. In this report, we analyze the data of brain infarction patients. The VC of both systolic and diastolic BPs was significantly higher in the brain infarction patients than in the control patients. Higher office BP variability was associated with a higher risk of brain infarction after adjustment for BP level and other confounding factors. Regarding diastolic BP, the association of brain infarction with the maximal value for the difference of office BPs taken at any consecutive two visits (Max-deltaBP) or the difference between the highest and lowest values of office BP (BP-range) recorded during a 1-year period prior to the event was also significant. In conclusion, a retrospective case-control study suggested that office BP variability was an independent predictor of brain infarction. Either the Max-deltaBP or the BP-range may be surrogate indices of diastolic BP variability.

Intake of potassium, magnesium, calcium, and fiber and risk of stroke among US men.

Animal experiments and epidemiological studies have suggested that high potassium intake may reduce the risk of stroke, but the evidence is inconclusive, and the role of other nutrients in potassium-rich foods remains unknown. We examined the association of potassium and related nutrients with risk of stroke among 43 738 US men, 40 to 75 years old, without diagnosed cardiovascular diseases or diabetes, who completed a semiquantitative food frequency questionnaire in 1986. During 8 years of follow-up, 328 strokes (210 ischemic, 70 hemorrhagic, 48 unspecified) were documented. The multivariate relative risk of stroke of any type for men in the top fifth of potassium intake (median intake, 4.3 g/d) versus those in the bottom (median, 2.4 g/d) was 0.62 (95% CI, 0.43, 0.88; P for trend=0.007). Results for ischemic stroke alone were similar. Intakes of cereal fiber and magnesium, but not of calcium, were also inversely associated with risk of total stroke. These inverse associations were all stronger in hypertensive than normotensive men and were not materially altered by adjustment for blood pressure levels. Use of potassium supplements was also inversely related to risk of stroke, particularly among men taking diuretics (relative risk, 0.36; 95% CI, 0.18, 0.72). Although these data do not prove a causal relationship, they are consistent with the hypothesis that diets rich in potassium, magnesium, and cereal fiber reduce the risk of stroke, particularly among hypertensive men. Potassium supplements may also be beneficial, but because of potential risks, use should be carefully monitored and restricted to men taking potassium-losing diuretics.