Pretreatment blood pressure as a predictor of 21-year mortality.

Our objective was to evaluate pretreatment predictors of longevity, particularly blood pressure, in a large cohort of hypertensive men. During 1974 to 1976, 10,367 male hypertensive veterans (47% black) were identified at screening and subsequently characterized in 32 special Veterans Administration (VA) hypertension clinics. Their mean age was 52 years and mean blood pressure (BP) 154/100 mm Hg. During an average of 21 years of follow-up, 61% died. Risk ratios for all-cause mortality as functions of BP and other risk factors are presented for each variable alone; for each variable controlling for age, race, and BP; and for a multivariate model. We observed that when the entire cohort was divided into deciles by systolic blood pressure (SBP) and by diastolic blood pressure (DBP), the risk ratios for 21-year mortality increased from lowest to highest decile by 178% for SBP and 16% for DBP. When the deciles were computed separately by age group, increases from lowest to highest decile for those less than 40 years of age were 138% for SBP and 263% for DBP. For those over 60 years, the increases were 154% and -10%, respectively. Although blacks were younger and had more severe diastolic hypertension than whites, the risk ratios were similar within each race group. Risk patterns for mean arterial pressure and pulse pressure resembled those for SBP but had smaller gradients. Survival curves for BP groups suggested constant mortality rates during follow-up. Other significant observations included decreasing mortality with increasing body mass index and increased mortality in the Stroke Belt. We concluded that pretreatment SBP strongly predicted all-cause mortality during 21-year follow-up. For the young, both SBP and DBP were strong predictors; for the elderly, only SBP was predictive.

The Washington University-EPRI Veterans' Cohort Mortality Study: preliminary results.

This article presents the design of and some results from a new prospective mortality study of a national cohort of about 50,000 U.S. veterans who were diagnosed as hypertensive in the mid 1970s, based on approximately 21 yr of follow-up. This national cohort is male with an average age at recruitment of 51 +/- 12 yr; 35% were black and 81% had been smokers at one time. Because the subjects have been receiving care at various U.S. Veterans Administration (VA) hospitals, access to and quality of medical care are relatively homogeneous. The health endpoints available for analysis include all-cause mortality and specific diagnoses for morbidity during VA hospitalizations; only the mortality results are discussed here. Nonpollution predictor variables in the baseline model include race, smoking (ever or at recruitment), age, systolic and diastolic blood pressure (BP), and body mass index (BMI). Interactions of BP and BMI with age were also considered. Although this study essentially controls for socioeconomic status by design because of the homogeneity of the cohort, selected ecological variables were also considered at the ZIP code and county levels, some of which were found to be significant predictors. Pollutants were averaged by year and county for TSP, PM10, CO, O3, and NO2; SO2 and Pb were considered less thoroughly. Both mean and peak levels were considered for gases. SO(4)2- data from the AIRS database and PM2.5, coarse particles, PM15, and SO(4)2- from the U.S. EPA Inhalable Particulate (IP) Network were also considered. Four relevant exposure periods were defined: 1974 and earlier (back to 1953 for TSP), 1975-1981, 1982-1988, and 1989-1996. Deaths during each of the three most recent exposure periods were considered separately, yielding up to 12 combinations of exposure and mortality periods for each pollutant. Associations between concurrent air quality and mortality periods were considered to relate to acute responses; delayed associations with prior exposures were considered to be emblematic of initiation of chronic disease. Preexposure mortality associations were considered to be indirect (noncausal). The implied mortality risks of long-term exposure to air pollution were found to be sensitive to the details of the regression model, the time period of exposure, the locations included, and the inclusion of ecological as well as personal variables. Both positive and negative statistically significant mortality responses were found. Fine particles as measured in the 1979-1984 U.S. EPA Inhalable Particulate Network indicated no significant (positive) excess mortality risk for this cohort in any of the models considered. Among the positive responses, indications of concurrent mortality risks were seen for NO2 and peak O3, with a similar indication of delayed risks only for NO2. The mean levels of these excess risks were in the range of 5-9%. Peak O3 was dominant in two-pollutant models and there was some indication of a threshold in response. However, it is likely that standard errors of the regression coefficients may have been underestimated because of spatial autocorrelation among the model residuals. The significant variability of responses by period of death cohort suggests that aggregation over the entire period of follow-up obscures important aspects of the implied pollution-mortality relationships, such as early depletion of the available pool of those subjects who may be most susceptible to air pollution effects.

Early predictors of 15-year end-stage renal disease in hypertensive patients.

There has been a continuing increase in the incidence of end-stage renal disease (ESRD) in the United States, including the fraction that has been attributed to hypertension. This study was done to seek relationships between ESRD and pretreatment clinical data and between ESRD and early treated blood pressure data in a population of hypertensive veterans. We identified a total of 5730 black and 6182 nonblack male veterans as hypertensive from 1974 through 1976 in 32 Veterans Administration Hypertension Screening and Treatment Program clinics. Their mean age was 52.5 +/- 10.2 years, and their mean pretreatment blood pressure was 154.3 +/- 19.0/100.8 +/- 9.8 mm Hg. During a minimum of 13.9 years of follow-up, 5337 (44.8%) of these patients died and 245 developed ESRD. For 1055 of these subjects, pretreatment systolic blood pressure (SBP) was greater than 180 mm Hg; 901 were diabetic; 1471 had a history of urinary tract problems; and 2358 of the 9644 who were treated had an early fall in SBP of more than 20 mm Hg. We used proportional hazards modeling to fit multivariate survival models to determine the effect of the available pretreatment data and early treated blood pressure levels on ESRD. This model demonstrated the independent increased risk of ESRD associated with being black or diabetic (risk ratio, 2.2 or 1.8), having a history of urinary tract problems (risk ratio, 2.2), or having high pretreatment SBP (for SBP 165 to 180 mm Hg, risk ratio was 2.8; for SBP > 180 mm Hg, risk ratio was 7.6).(ABSTRACT TRUNCATED AT 250 WORDS)

Regional differences in mortality during 15-year follow-up of 11,936 hypertensive veterans.

Several different investigators have reported increased stroke mortality in the southeastern United States, leading to the introduction of the term "Stroke Belt." The results presented here from the Veterans Administration Hypertension Screening and Treatment Program (HSTP) demonstrate an increased all-cause mortality among hypertensive patients seen in HSTP clinics in the southeastern United States when compared with similar patients from other HSTP clinics. Several different groupings of southeastern states were examined and compared with nine states west of the Mississippi River. A total of 11,936 male veterans, 5737 of whom were black, were identified as hypertensive during 1974-1976 in 32 HSTP clinics. Their mean age was 52.4 +/- 10.4 years, and their mean pretreatment blood pressure was 153.8 +/- 19.1/100.4 +/- 9.8 mm Hg. During a minimum of 13.9 years of follow-up, 5360 (44.9%) of these patients died. Proportional hazards modeling was used to fit a basic survival model with terms representing race, age, blood pressure, smoking, and obesity. Risk was increased with higher blood pressure, age, and smoking and with lower body mass index. For 6 HSTP clinics in an 11-state Stroke Belt (defined as states with stroke mortality > 10% above the United States average), the relative risk of death was 1.226 (95% confidence interval, 1.106-1.358) when compared with 9 states west of the Mississippi River. For two different groupings of southeastern states with 10 and 8 HSTP clinics the relative risk of death was 1.231 and 1.295.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of 'stroke-belt' residence, screening blood pressure and personal history risk factors on all-cause mortality among hypertensive veterans.

OBJECTIVES: To seek regional differences within the USA in the 'all-cause mortality' of hypertensive men during the 14 years following institution of antihypertensive treatment, and to determine how other pretreatment data can be related to that all-cause mortality. DESIGN: In the mid-1970s pretreatment clinical data were collected and computerized for 5698 hypertensive veterans. Deaths during the subsequent 14 years were obtained from the Veterans Administration Beneficiary Identification and Record Location System and the National Death Index. Relationships between pretreatment data and death were sought using chi 2- and z-tests for bivariate comparisons and logistic regression for multivariate analyses. PATIENTS: Half of the 5698 previously untreated male hypertensive military veterans were Black. Their mean age was 52.3 years and mean pretreatment blood pressure was 160/104 mmHg. Additional pretreatment data included body mass index, cigarette and alcohol usage, age and self-reported comorbidities. These patients began antihypertensive treatment during 1974-1975 in 28 special Veterans Administration outpatient clinics throughout the USA. RESULTS: During the 14 years after treatment began, 2283 of these patients (40%) died. Those from the southeastern USA, i.e. in the 'Stroke Belt', were 1.32-fold more likely to die than patients living elsewhere. Other pretreatment characteristics positively related to all-cause mortality included age, systolic blood pressure, cigarette and alcohol usage, and self-reported comorbidities. Race was unrelated to mortality. CONCLUSION: All-cause mortality was increased among hypertensive subjects from the southeastern USA. The reasons for this excess mortality remain unclear. Other pretreatment characteristics were also related to mortality, but race was not.