摘要:

Medical records were examined for 1935 patients who presented sequentially to a hypertension clinic between 1971 and 1981. Patients were classified according to whether they were on a β -blocker, methyldopa, a potassium-losing diuretic, or whether they had discontinued any of these treatments. Age-standardized mortality rates were calculated and the relative risks of stopping compared with non-stopping were computed.Those stopping a β -blocker had a significantly higher mortality in the following year than those who continued, both in men [relative risk (RR)=5.91, 95% confidence interval (Cl) 2.78-12.56] and women (RR=5.67, 95% Cl 1.75-18.41). Moreover, women also had a significantly higher mortality when stopping methyldopa, compared with those who continued on the drug (RR=4.91, 95% Cl 1.82-13.20). However, analysis of data from the years following withdrawal indicated that a high RR was not limited to the first year after the withdrawal of β -blockers, but was still apparent in the fourth year after stopping. This indicates that the high mortality was not an early function of withdrawal. The high initial RR of mortality in women stopping methyldopa was followed by a substantial decrease in risk over the later years of follow-up.The high mortality in patients stopping particular antihypertensive drugs was not explained by known cardiovascular risk factors.

ISSN:0263-6352    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

Chronic exposure to a shock-shock conflict paradigm (2 h/day, 5 days/week for 12 weeks [1]) produces hypertension in the borderline hypertensive rat (BHR), a cross between the spontaneously hypertensive rat (SHR) and the Wistar-Kyoto rat (WKY). The purpose of the present study was to characterize the regional haemodynamic responses which take place during conflict-stress.A pulsed Doppler flowmeter and miniature probes implanted on the left renal and superior mesenteric arteries and the abdominal aorta were used to record changes in regional flow velocity. Recording of mean arterial pressure (MAP) allowed changes in regional resistance to be calculated.The first conflict session produced intense splanchnic and renal vasoconstriction and hindquarter vasodilation. Pressor responses were moderate. A second group of BHRs was studied during conflict sessions 17-18, prior to the development of hypertension. This group exhibited faster habituation to the stress than the group studied during the first conflict session: MAP and mesenteric resistance returned more rapidly towards pre-stress levels. Relative to naive control rats, this group exhibited a larger peak MAP and less tachycardia in response to a neutral stressor (air-jet stress) and a smaller reduction in renal resistance in response to ganglionic blockade.These data suggest that in this model, pressure load per se is moderate. More attention should be directed towards the role of trophic effects of the neurohumoral factors responsible for the pronounced constriction of splanchnic and renal vasculature in producing hypertension.

ISSN:0263-6352    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

Systolic (SBP), diastolic (DBP) and mean [MBP = diastolic + ⅓ (systolic – diastolic)] blood pressures were compared as predictors of all causes of death (ALL) and of deaths from atherosclerotic cardiovascular disease (ACVD) in 2480 men, aged 40–59 years, belonging to three cohorts followed up for 20 years. Both univariate analysis, based on distribution of events in age-specific quintile classes of blood pressures, and multivariate analysis, based on the Cox proportional hazards model with five covariates as possible confounders, clearly showed the superiority of SBP over DBP in predicting fatal events; MBP played an intermediate role.

ISSN:0263-6352    

出版商:OVID    

年代:1989

数据来源: OVID