@article {1447, title = {Properties of the random zero sphygmomanometer.}, journal = {Hypertension}, volume = {21}, year = {1993}, month = {1993 May}, pages = {632-7}, abstract = {

The random zero sphygmomanometer is widely used in studies involving blood pressure measurement because it is believed to eliminate digit preference and reduce measurement error. We performed blood pressure measurements sequentially using random zero and standard sphygmomanometers in random order in 1,356 participants in the Cardiovascular Health Study. Despite adherence to the manufacturer{\textquoteright}s instructions, we observed a substantially nonuniform distribution of zero levels generated by the random zero sphygmomanometer and a disturbing correlation between the zero level and blood pressures taken with the standard sphygmomanometer. With the random zero device, the pooled estimated slopes for the regression of standard systolic and diastolic pressures on the zero level were -0.71 and -0.17, respectively (both p < 0.0001). The only plausible explanation for this relation between the random zero device and the standard device is that by some unknown mechanism the subject{\textquoteright}s blood pressure is influencing the zero level. Systolic and diastolic blood pressures measured with the random zero device were, respectively, 1.65 and 1.84 mm Hg lower (both p < 0.0001) than standard blood pressures. Digit preference was detectable in the uncorrected blood pressure and zero level measured with the random zero device but was eliminated after calculation of the corrected blood pressure. For most epidemiological studies, the random zero sphygmomanometer offers no significant advantage over the standard sphygmomanometer. It may still be useful in those epidemiological studies and clinical trials where blinding is important.

}, keywords = {Aged, Blood Pressure, Blood Pressure Determination, Cohort Studies, Diastole, Humans, Regression Analysis, Systole}, issn = {0194-911X}, author = {Kronmal, R A and Rutan, G H and Manolio, T A and Borhani, N O} } @article {1437, title = {Correlates of blood pressure in community-dwelling older adults. The Cardiovascular Health Study. Cardiovascular Health Study (CHS) Collaborative Research Group.}, journal = {Hypertension}, volume = {23}, year = {1994}, month = {1994 Jan}, pages = {59-67}, abstract = {

Although elevated blood pressure is an important predictor of cardiovascular disease and stroke in the elderly, little information exists on the distribution and risk factor correlates of blood pressure in this group. As part of the Cardiovascular Health Study, a population-based cohort study of 5201 men and women aged 65 to 101 years, we investigated correlates of systolic and diastolic blood pressure. Multiple regression analyses were conducted for all participants and a subgroup of 2482 without coronary heart disease and not on antihypertensive therapy (the "healthier" subgroup). In the total group, independent predictors of diastolic blood pressure included heart rate, aortic root dimension, creatinine, hematocrit, alcohol use, and black race (positive associations) and internal carotid artery wall thickness, mitral early/late peak flow velocity, white blood cell count, cigarette smoking, and age (negative associations). Positive predictors of systolic blood pressure included mitral late peak flow velocity, left ventricular mass, common carotid artery wall thickness, serum albumin, factor VII, diabetes, alcohol use, and age; negative predictors were coronary heart disease, uric acid, height, and smoking. In the healthier subgroup, positive predictors of diastolic blood pressure included heart rate, hematocrit, serum albumin, creatinine, and body weight, whereas mitral early/late peak flow velocity, serum potassium, smoking, and age inversely related to diastolic pressure. For the same group, common carotid artery wall thickness, left ventricular mass, serum albumin, factor VII, high-density lipoprotein cholesterol, and age were directly related to systolic blood pressure, whereas serum potassium was inversely related. Both systolic and diastolic pressures varied considerably by geographic site.(ABSTRACT TRUNCATED AT 250 WORDS)

}, keywords = {Aged, Aged, 80 and over, Aging, Blood Pressure, Cohort Studies, Coronary Disease, Female, Health Surveys, Humans, Hypertrophy, Left Ventricular, Male, Regression Analysis, United States}, issn = {0194-911X}, author = {Tell, G S and Rutan, G H and Kronmal, R A and Bild, D E and Polak, J F and Wong, N D and Borhani, N O} } @article {1493, title = {The association of antihypertensive medication with serum creatinine changes in older adults.}, journal = {Am J Hypertens}, volume = {10}, year = {1997}, month = {1997 Dec}, pages = {1368-77}, abstract = {

Many of the potential effects of antihypertensive therapy, including renal function, have been inadequately investigated in clinical trials in older adults. In an observational study, we examined the association between treatment with various classes of antihypertensive agents and 3-year changes in serum creatinine in 1296 older adults with treated hypertension and without prior renal disease (mean age 72.2 years; 60\% female; 30\% diabetic; 42\% with cardiovascular disease (CVD)) from the Cardiovascular Health Study. Baseline antihypertensive medications included thiazides (HCT), beta-adrenergic blockers, angiotensin converting enzyme inhibitors (ACE-I), calcium channel blockers (CCB), vasodilators (VAS), HCT + BB, HCT + ACE-I, HCT + CCB, HCT + VAS, loop diuretics (LOOP), and other combinations. Unadjusted results indicated that minimal changes in mean serum creatinine occurred over time for all therapies and only a few changes were statistically significant (HCT: +0.02 mg/dL, ACE-I: +0.04, CCB: +0.04; all P < .05; LOOP: +0.06 mg/dL; P < .001). In multivariate analyses with HCT users as the reference group and adjusting for baseline serum creatinine, age, sex, smoking, diabetes mellitus, CVD, height, weight, common carotid intima-media thickness, and use of allopurinol, phenytoin, cimetidine, and nonsteroidal antiinflammatory drugs, all of the relative changes were small and statistically nonsignificant except for HCT + VAS users (+0.07 mg/dL; P < .05). When users of the same therapy at baseline and follow-up were restricted, only LOOP users had significant albeit small changes in serum creatinine (+0.05 mg/dL; P < .05). Although results from clinical trials are needed to confirm these findings, these observational data suggest no major differences between specific antihypertensive therapies in 3-year serum creatinine changes in older adults without prior renal disease.

}, keywords = {Aged, Antihypertensive Agents, Cohort Studies, Creatinine, Female, Humans, Male}, issn = {0895-7061}, author = {Smith, N L and Psaty, B M and Heckbert, S R and Lemaitre, R N and Kates, D M and Rutan, G H and Bleyer, A} }