Parental Hypertension and Cardiovascular Response to Cognitive and Isometric Challenge

The purposes of this investigation were to contrast the cardiovascular responses of sons of hypertensive and normotensive parents to tasks involving cognitive and isometric challenge, and lo examine the relationship of individual differences in heart rate (HR) reactivity to baseline blood pressure (BP) measurements. Thirty-six male, undergraduate volunteers (18 with and 18 without a parental history of hypertension) were scheduled for two, 1-hr experimental sessions (Days I and II). On Day 1, HR and BP measurements were obtained while subjects performed each of three laboratory tasks: a difficult test in concept formation, serial subtraction, and a sustained handgrip at 30% of maximum voluntary contraction. Each task lasted 3 min and was preceded by a 3-min baseline interval. On Day II, subjects were instructed to relax quietly while baseline measures of HR and BP were recorded. Relative to sons of normotensive parents, offspring of hypertensives exhibited higher mean Systolic BPs during all task periods; no corresponding group differences were observed on either Day I or Day II baseline recordings. Unlike SBP, Diastolic BP measurements did not vary reliably by parental hypertensive/normotensive status. Although the mean HRs of sons of hypertensives were significantly higher than in offspring of normotensives, these differences obtained uniformly across both the baseline and task intervals. Among subjects identified as High HR reactors during the two cognitive tasks, sons of hypertensive parents exhibited Day II baseline SBPs about 9 mmHg higher than did subjects without a parental history of hypertension. Among subjects identified as Low HR reactors, baseline SBPs did not differ reliably between sons of hypertensive and normotensive parents.     

Effects of relative blood volume-controlled hemodialysis on blood pressure and volume status in hypertensive patients

In hypertensive hemodialysis (HD) patients, dry weight reduction to normalize blood pressure (BP) often results in increased frequency of HD hypotension. Because HD with blood volume tracking (BVT) has been shown to improve intra-HD hemodynamic stability, we performed a prospective, randomized study to test whether BVT is more effective than standard hemodialysis (SHD) in the management of hypertension by dry weight reduction. After a run-in period of 4 weeks on SHD, 28 patients were randomly assigned for a 12-week treatment period with either SHD (n = 14) or BVT (n = 14). The mean pre-HD and post-HD weight did not change over time in either group. In the BVT group, pre-HD systolic and diastolic BP decreased on average 22.5 mm Hg and 8.3 mm Hg, respectively (both p < 0.05), whereas BP did not change in the SHD group. Extracellular water and cardiothoracic ratio decreased significantly (all p < 0.05) in the BVT group but not in the SHD group. Brain natriuretic peptide levels declined only in the BVT group, without reaching statistical significance. The frequency of HD hypotensive episodes decreased significantly (p < 0.05) in the BVT group and was unchanged in the SHD group. HD with BVT was associated with a significant reduction in pre-HD BP. At the same time, the frequency of intra-HD hypotensive episodes decreased. Although the mean weight did not change, the reductions in cardiothoracic ratio and extracellular water suggest that HD with BVT resulted in optimization of volume status.     

Continuous positive airway pressure lowers blood pressure in hypertensive patients with obstructive sleep apnea

Summary Question of the study Obstructive sleep apnea (OSA) and hypertension are frequently associated and probably causally related. We investigated the influence of continuous positive airway pressure (CPAP) on blood pressure (BP) in OSA. Patients and Methods Fourty-four patients in whom CPAP-therapy had been successfully applied for treatment of OSA (median apnea-hypopopnea-index [AHI] 57.5/h) were included. Non-invasive 24-hour BP was measured at 15  min intervals before and with CPAP. Results After 1 – 3 days of CPAP, 24-hour systolic and diastolic BP in the hypertensive patients (n = 32) decreased from a median of 141 (129 – 173, 25 % – 75 % interquartile range) mmHg to 136 (118 – 157) mmHg (p = 0.004) and from 90 (80 – 107) mmHg to 88 (77 – 99) mmHg (p = 0.001), respectively, but was unchanged in the normotensives (n = 10). After 4 – 6 months of CPAP, 24-hour systolic and diastolic BP in a hypertensive subgroup (n = 19) decreased from a median of 140 (131 – 142) mmHg to 131 (122 – 143) mmHg (p = 0.01) and from 88 (86 – 94) mmHg to 84 (80 – 87) mmHg (p = 0.02), respectively, but was unchanged in a normotensive subgroup (n = 8). After long-term CPAP, there was a small weight reduction in the hypertensive patients. Subgroup analysis of 13 hypertensives with stable weight confirmed a significant BP-reduction. Conclusions In OSA with associated hypertension, CPAP has a specific BP-lowering effect. This suggests that both disorders are causally related.     

Naloxone effects on blood pressure,analgesia and diuresis in spontaneous hypertensive and normotensive rats

Studies were performed in unanesthetized normotensive and spontaneously hypertensive rats (SHR) to compare the effects of naloxone. In normotensive Wistar rats, naloxone did not change blood pressure (BP) and nociceptive threshold, but it induced a dose-related diuretic response. Whereas in SHR naloxone decreased nociceptive threshold and lowered BP when given intracerebroventricularly, it failed to significantly modify diuresis. These differences between hypertensive and normotensive rats in their responses to naloxone may be explained by the fact that vasopressin (VP) levels and opioid activity are different in SHR.     

Morbidity and mortality in relation to blood pressure and antihypertensive treatment. A 12-year follow-up study of a population sample of Swedish women

Morbidity and mortality in cardiovascular and cerebrovascular diseases and total mortality have been studied in a longitudinal population study initially comprising 1462 women representative of the general female population. When related to the initial blood pressure (BP) levels of women not on antihypertensive drugs (hypertensives and non-hypertensives), the distributions of women with myocardial infarction (MI) and stroke during the 12-year follow-up period seemed to be U-shaped, with the highest incidences in women with the lowest and the highest BP levels. Women recognized as untreated hypertensives in the initial study were offered regular control by the study team during the whole 12-year period and were treated when treatment was considered indicated. They were found to be similar to the non-hypertensives with regard to the incidence of MI and stroke and total mortality. Our encouraging results may be explained by continuity of medical care, the antihypertensive treatment per se or the types of antihypertensive drugs administered.     

Different effects of eicosapentaenoic acid and olive oil on blood pressure,intracellular free platelet calcium,and plasma lipids in patients with essential hypertension

Summary In a randomized, double-blind, crossover study our specific aim was to examine the effects of a dietary fish oil or olive oil supplementation on blood pressure, intracellular free platelet calcium, plasma lipoproteins, and circulating vasoactive substances such as norepinephrine, epinephrine, and renin in patients with essential hypertension. Ten hypertensive patients (WHO classes I, II) were randomly assigned to receive 9 g fish oil or 9 g olive oil daily for 6 weeks after a 4-week baseline period. The 6-week treatment periods were separated by a 4-week wash-out. During treatment with fish oil diastolic blood pressure decreased from 103±1 to 98±2 mmHg (P<0.05) but did not change significantly during olive oil intake. Systolic blood pressure was not affected by either treatment. Intracellular free platelet calcium decreased in patients receiving fish oil (from 102±8 nM to 86±6 nM, P < 0.05) but was not significantly altered by olive oil treatment. In contrast, the dose-response curve for thrombin-induced intracellular free platelet calcium was not altered by the fish oil enriched diet. Plasma triglycerides decreased by approximately 40% in the fish oil group while low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and total cholesterol were not altered. Renin activity, norepinphrine, and epinephrine in plasma were not influenced by fish oil supplementation. We conclude that a moderate increase in dietary fish oil reduces diastolic blood pressure, intracellular free platelet calcium, and plasma triglycerides in patients with essential hypertension. The decrease in basal intracellular free platelet calcium concentration does not seem to be due to a diminished responsiveness of the calcium messenger system to thrombin.This work was supported by a grant from the Deutsche Forschungsgemeinschaft (DFG) Ha-1388/2-3     

Elevated ambulatory blood pressure in 20 subjects with Williams syndrome

Previous studies report conflicting frequencies of hypertension in cohorts of patients with Williams syndrome (WS). We studied blood pressure (BP) in WS using 24-hour ambulatory BP monitoring. This technique reliably measures day- and nighttime BP in a subject's natural environment and provides better prognostic information on long-term risks of hypertension than casual BP determinations. Twenty WS subjects evaluated through a multidisciplinary WS clinic and 35 age and gender-matched controls were studied. We found that WS subjects had significantly higher ambulatory BP than controls. After controlling for age, sex, and weight, the diagnosis of WS added approximately 10 mmHg to mean daytime and nighttime BPs. Hypertension, as defined by elevated mean daytime BP, was present in 40% of WS subjects versus 14% of controls (P < 0.05); among the children studied this difference was even more dramatic with 46% of WS children versus 6% of control children classified as hypertensive (P = 0.01). We also demonstrated normal diurnal BP variation but no evidence of a "white coat" effect or increased BP variability. Interestingly, parental reporting of a history of infantile hypercalcemia was strongly associated with the presence of hypertension (P = 0.008). Our data demonstrate that both children and adults with WS have higher mean BP and higher frequency of hypertension than healthy controls. Thus, elevated BP readings in the office setting should not be dismissed but require more thorough assessment.     

Effects of parental history of hypertension and urbanization on blood pressure in zimbabweans

The increasing prevalence of essential hypertension is a growing public health concern for Zimbabwe and other African countries. Two important risk factors for hypertension are urbanization and parental history of hypertension. The relations among parental history of hypertension, urbanization, and blood pressures (BPs) are poorly understood. The objective of this study is to clarify these relations in a population of urbanized. African, young adults. The relation between parental history of hypertension and urbanization on resting BPs and BP responses to a menial arithmetic stressor was examined in a group of normotensive, Black medical students with (n = 36) and without (n = 34) a parental history of high BP.and with (n = 49) and without (n = 19) a parental history of urbanization. Results indicate that those with a positive parental history of high BP had higher resting BPs and greater systolic blood pressure (SBP) increases in response to laboratory stress, when compared to their negative parental history counterparts. Further, those with parents residing in urban areas had higher resting SBPs than those with parents residing in rural areas. However, no reactivity differences were apparent between the urban and rural parent groups. These data suggest that although parental history for hypertension influences both resting and reactivity BPs, parental history of urbanization may influence only resting BP. This study was supported by NIH/Fogarty International Center Grants 5T37TW3041-02, N1H-HL35195. and NIH-HL32738.     

Time course of decrease in blood pressure and in blood pressure response to vasopressor agents during pregnancy in the rat

Summary In the unanesthetized normotensive rat blood pressure progressively decreased during the last week of pregnancy as measured with a direct and an indirect method. In renal hypertensive and desoxycorticosterone acetate (DOCA)-salt hypertensive rats blood pressure also decreased at this time. In the unanesthetized normotensive rat the blood pressure response to exogenous rat renin diminished progressively during the last week of pregnancy. Similarly, the blood pressure response to angiotensin II, noradrenaline and tyramine decreased. The decrease in blood pressure induced by acetylcholine was not affected during pregnancy. Determination of the activity of the renin-angiotensin system showed that plasma renin activity was elevated to 3–4 times the control value on day 20–21 of pregnancy, and that plasma renin substrate was decreased on day 14–15. It is suggested that the decrease in blood pressure which occurs during the last week of pregnancy in the rat is mediated through a decreased responsiveness of the cardiovascular system to vasopressor agents.     

The impact of the improvement of insomnia on blood pressure in hypertensive patients

This study investigated the impact of the improvement of insomnia on the blood pressure levels of hypertensive patients. A total of 402 patients with a diagnosis of insomnia and hypertension were selected and randomly divided into two groups. The treatment group (202 cases) received standard anti‐hypertensive treatment with Estazolam, and the control group (200 cases) received standard anti‐hypertensive treatment with placebo. The sedentary diastolic and systolic blood pressures were measured before the treatment and every 7 days during the experiment. To assess the sleep quality and anxiety and depression levels of patients, the scores of the Pittsburgh Sleep Quality Index, the Hamilton Anxiety Rating Scale and the Hamilton Depression Scale‐17 were reported at the same time points. At the conclusion of the experiment, the Pittsburgh Sleep Quality Index, Hamilton Anxiety Rating Scale and Hamilton Depression Scale‐17 scores of the treatment group were significantly lower than those of the control group (P < 0.001). The insomnia treatment efficacy of Estazolam in the treatment group was 67.3%, significantly higher than that (14.0%) of the control (P < 0.001). The blood pressure of the treatment group showed significant improvement throughout the experiment. By Day 28, the decrease of sedentary diastolic and systolic blood pressures in the treatment group was significantly greater than that of the control (sedentary systolic blood pressure: 10.5 ± 3.9 versus 3.4 ± 2.5 mmHg; sedentary diastolic blood pressure: 8.1 ± 3.6 versus 2.7 ± 2.1 mmHg, P < 0.001), and the compliance rate of goal blood pressure (< 140/90 mmHg) was 74.8% with Estazolam, compared with 50.5% with placebo (P < 0.001). Thus, the current findings indicated that the improvement of insomnia can significantly help lower blood pressure in hypertensive patients.     

Arterial blood pressure and general sympathetic activation in essential hypertension during stimulation

We asked whether exaggerated blood pressure (BP) reactivity in patients with essential hypertension (HT) is a sign of specific activation of the cardiovascular system or of generalized sympathetic activation. Fourteen patients with essential hypertension and 14 matched normotensive (NT) controls were subjected to tasks involving attentional demands, mental arithmetic, a cold pressor test and isometric muscular contraction. Systolic and diastolic BPs, skin and muscle blood flows, heart rate, skin conductance level and fluctuations during each task were recorded. Urine samples for determination of epinephrine and norepinephrine excretion were collected after task completion. All tasks caused BP increases in both groups. HT showed greater absolute and percentage BP reactivity than NT during isometric muscle contraction. Variables for which reactivity differences were observed were poorly correlated across tasks both in HT and NT, whereas resting values prior to each task were highly correlated in both groups. Skin conductance activity, epinephrine and norepinephrine excretion rates being examples of non-cardiovascular sympathetic nervous system (SNS) indicators did not separate HT from NT. Thus, the exaggerated pressor response in HT is not accompanied by signs of generalized SNS activation.     

Microalbuminuria in essential hypertension: clinical and biochemical profile

This study aims to evaluate the clinical and biochemical profile associated with the presence of microalbuminuria in a group of essential hypertensive patients referred to a hypertension clinic. A total of 188 non-diabetic, untreated essential hypertensive patients (100 men, 88 women) aged 55.8 +/- 11.7 years are studied. Urinary albumin excretion was determined in two 24-h urine collections. Clinical and biochemical evaluations and 24-h ambulatory blood pressure (BP) monitoring were performed at baseline. Forty-two patients (22.3%) showed an increased urinary albumin excretion rate (20-200 micrograms/min). These patients showed significantly higher values (P < 0.01) for 24-h, daytime and night-time systolic and diastolic BP, compared with essential hypertensives with normal urinary albumin excretion. However, nocturnal reduction in BP did not differ between the groups. Furthermore, patients with microalbuminuria showed significantly higher (P < 0.01) creatinine, serum uric acid and triglycerides, as well as lower high-density lipoprotein (HDL)-cholesterol. In a multiple logistic regression analysis, a 24-h systolic BP > 140 mmHg (odds ratio: 3.19; 95% confidence interval [CI 95%]: 1.44-7.06) and a serum creatinine > 88 mumol/L (odds ratio: 3.08; CI 95%: 1.39-6.84) were the two factors associated independently with increased urinary albumin excretion. We conclude that, in essential hypertensive patients, the presence of microalbuminuria is associated with elevated BP, but not with its circadian pattern. Likewise, microalbuminuria is associated with the degree of renal impairment, and with increased uric acid and triglycerides and decreased HDL-cholesterol.     

Determinants of circadian blood pressure rhythm and blood pressure variability in obstructive sleep apnoea

SUMMARY  The prevalence of hypertension in patients with obstructive sleep apnoea (OSA) is high and blood pressure profile is characterized by nocturnal blood pressure (BP) elevation and increased nocturnal BP variability. Ambulatory 24-hour-biood pressure monitoring (ABPM) is a valid, non-invasive method to describe circadian BP variation. Circadian BP profile and nocturnal BP variability were related to OSA severity (apnoea-hypopnoea index, mean low O₂), age and body mass index (BMI) in 73 patients with OSA. Prevalence of hypertension was 75%, and in 59% BMI was greater than 30 kg m^-2. A nocturnal decline of at least 10% from daytime mean BP values (night/day BP ratio <0.9; dipper) was found in only 25% of hypertensive patients and 39% of normotensive patients. Comparison between dippers and non-dippers showed significant differences in apnoea severity (apnoea-hypopnoea index 32 + 19 vs. 50 + 23/h, P <0.01; mean low O₂ 84.5 + 4 vs. 80.2 + 5.8%, P< 0.01) but not for age and BMI. In multiple regression analyses with age, body mass index, apnoea-hypopnoea index and mean low O₂ as independent and BP ratios and BP variability as dependent variables, sleep apnoea severity was the only independent predictor for circadian BP rhythm and nocturnal BP variability. The results presented here suggest that independent of age and obesity the severity of sleep apnoea is an important determinant of circadian BP variation and nocturnal BP variability.     

Cardiovascular reactivity of patients with essential and renal hypertension in an emotion-triggering interview

Blood pressure reactivity to mental stress in hypertensives is much higher than in normotensives. The authors' aim in this study was to examine whether different cardiovascular responses can be induced by various stimuli in hypertensive subgroups. The authors matched 10 essential hypertensives (EHs), 10 renal hypertensives (RHs), and 10 normotensives (Ns) according to age and gender examined them during an emotion-stimulating interview, and measured blood pressure (BP) and heart rate (HR) during the phases of the interview. They observed differences in BP reactivity between EHs/RHs and Ns under some stimuli but not between EHs and RHs, as well as a marked difference in the product of systolic BP (SBP) and HR between both hypertensive groups in the anger/rage phase (p = .028) and the baseline 2 (p = .02). This shows a higher cardiovascular activation under mental stress and a lower recovery in EHs and more sensitivity to perturbation or higher central tension compared with RHs.     

High-dose terazosin therapy (5mg) in Korean patients with lower urinary tract symptoms with or without concomitant hypertension: a prospective, open-label study

PURPOSE: We determined the efficacy and safety of a relatively high dose of terazosin (5mg) in Korean patients with lower urinary tract symptoms (LUTS), with or without concomitant hypertension. MATERIALS AND METHODS: From July to December 2006, 200 men who consecutively presented with LUTS were prospectively studied. Eight weeks after treatment, blood pressure (BP), uroflowmetry, and International Prostate Symptom Score (I-PSS) were assessed. For analysis purposes, patients were stratified according to concomitant hypertension. Of the 200 patients, 173 completed the scheduled eight-week treatment period. RESULTS: At baseline, no differences were evident in the two groups in terms of I-PSS, Qmax, PVR and BP. After eight weeks of treatment-although I-PSS and uroflowmetry parameters were not significantly different in the two groups-systolic and diastolic BP in the non-hypertensive control group were higher than in the hypertensive group (p= 0.001 and p=0.0100, respectively). Changes in I-PSS, uroflowmetry parameters, and BPs measured at week eight post- treatment commencement did not significantly differ between the two groups. Moreover, the addition of 5mg of terazosin to antihypertensives did not cause a significant reduction in either systolic or diastolic BP in either group. CONCLUSION: Adding terazosin to existing antihypertensive regimens did not seem to increase the incidence of adverse events. Our findings suggest that 5mg terazosin is effective and that it has an acceptable safety profile as an add-on therapy for patients with LUTS and concomitant hypertension.     

Altered calcium metabolism in red blood cells of hypertensives: Persistent marker or sequel of essential hypertension?

Summary The characteristics of the increased calcium (Ca) influx observed in metabolically depleted red blood cells (RBCs) of hypertensive patients were investigated. Twenty-four normotensives, 16 untreated essential hypertensives, and 10 essential hypertensives under sufficient blood pressure control by 50–100 mg/day atenolol were studied. Free intracellular concentrations of Ca, sodium (Na), and potassium (K) were assessed using ion-selective electrodes in freeze-thawed RBCs, which were metabolically depleted by 30 mM desoxy-glucose at 37°C for 48 h. In the treated hypertensives values for Ca and K at 24 and 48 h were not different from values for the normotensives, whereas elevated Ca was found in RBCs of untreated hypertensives. Na in treated hypertensives was significantly increased at 0 and 48 h, thus, being similar to values for untreated hypertensives. Additionally, RBCs of six normals were stressed in a glass/teflon potter. Before metabolic depletion electrolytes were not affected by this procedure, while Ca at 24 and 48 h of metabolic depletion increased to significantly higher values for the hypertensive patients as compared to the controls. These results suggest that the altered Ca metabolism in the RBCs of hypertensives may reflect a secondary phenomenon due to the mechanical damage to RBCs by the elevated blood pressure.     

Denial is associated with higher ambulatory blood pressure across the menstrual cycle

Background: Studies show that stress perception is associated with increased daily ambulatory blood pressure (BP) and that denying the negative effects of stress increases BP as well. Whether these effects persist over the menstrual cycle is unknown.

Aim: To examine the effects of measures of stress and stress denial on ambulatory work and home BP during the follicular and luteal phases of the menstrual cycle.

Subjects and methods: Seventy-one women (age?=?34.9?±?7.7 years) employed as secretaries or technicians wore an ambulatory BP monitor during the follicular (between day 7–10; Mean?=?8?±?2) and luteal (between day 19–25; Mean?=?22?±?2) phases of their cycle. During each phase, relationships between BPs averaged at work and home and various stress measures and demographic and anthropometric variables were examined using stepwise regression.

Results: Ambulatory BPs did not change from the follicular to luteal phase. Stress denial was generally associated with higher ambulatory BP (p?Conclusion: Stress denial has a persistent effect on BP, regardless of menstrual phase; however, shifts in the hormonal environment throughout the menstrual cycle may mediate other somatic and behavioural associations with BP.     

Organisational factors in relation to control of blood pressure: an observational study

BACKGROUND: Studies show that 60-75% of treated patients with hypertension in general practice, still do not reach the recommended blood pressure targets of <150/90 mmHg. AIM: To investigate aspects of hypertension management in relation to sociodemographic variables, antihypertensive drug treatment, and organisational factors in primary care. DESIGN OF STUDY: Observational study over 3 years. SETTING: Eight general practices in Tayside, UK. METHOD: Participants were 560 randomly selected patients aged 40-79 years receiving treatment for hypertension. The outcome measurement was blood pressure control, expressed in binary form based on the British Hypertension Society audit standard of <150/90 mmHg. RESULTS: Of 536 eligible patients, 261 (49%) were defined as having inadequate blood pressure control at the end of the study period. No significant associations were discovered with sex, age, deprivation score and comorbidity. In those patients with inadequate control, 30% had no modifications to their drug treatment during the study period. Blood pressure control at the end of the study period was not associated with number of antihypertensive drugs taken or number of antihypertensive drug modifications. The mean number of clinician contacts was 11 (standard deviation = 8), and mean continuity in primary care was high, although this was not associated with improved blood pressure control. A higher proportion of hypertension-related consultations were associated with increased odds of having inadequate blood pressure control. CONCLUSION: Achieving adequate blood pressure control continues to represent a substantial health problem in a significant proportion of the hypertensive population. Patient, physician and organisational elements play a role in ensuring effective delivery of hypertension care in the community.     

Effect of family responsibilities and job strain on ambulatory blood pressure among white-collar women

OBJECTIVE: This study was conducted to determine whether large family responsibilities and their combination with high job strain were associated with an increase in ambulatory blood pressure (BP) among white-collar women. METHODS: A cross-sectional study was conducted in a stratified random sample of 199 white-collar women with or without children who were employed full time in jobs involving high or low strain. These women were selected from a population of 3183 women of all ages, employed in eight organizations in Quebec City, Canada. Subjects wore an ambulatory BP monitor for 24 hours during a working day. Mean BPs were calculated. Different measures of family responsibilities were used, based on the number of children and their ages, and domestic work. Job strain was measured using the Job Content Questionnaire recommended by Karasek. RESULTS: Family responsibility measures were significantly related to diurnal BP among women holding a university degree (N=69). Indeed, women having large family responsibilities had increases in systolic and diastolic BPs of 2.7 to 5.7/1.8 to 4.0 mm Hg (p< or =.05). Among women holding a university degree, increases in diurnal systolic and diastolic BPs reached 8.1 to 10.9/5.5 to 7.1 mm Hg (p< or =.01) among women having both large family responsibilities and high job strain. These results were independent of confounders. There was no significant association among women without a university degree (N=130). CONCLUSIONS: Large family responsibilities were associated with significant increases in diurnal systolic and diastolic BPs among white-collar women holding a university degree. In these women, the combined exposure of large family responsibilities and high job strain tended to have a greater effect on BP than the exposure to only one of these factors.     

Caffeine, extended stress, and blood pressure in borderline hypertensive men

Caffeine increases blood pressure (BP), and its pressor effects are larger in borderline hypertensive (BH) men than in controls. This article extends findings of larger caffeine effects on BP at rest and to brief mental stress in BH to a new analysis of caffeine and prolonged mental stress in BH. In a double-blind, crossover study, 24 male BH (140/90 mmHg < BP < 160/95 mmHg) and 23 normotensive controls who were habitual caffeine consumers (NT; BP < 135/85 mmHg; negative parental history) worked on alternating mental stressors for 35 min after placebo or caffeine (3.3 mg/kg). Caffeine raised systolic blood pressure (SBP) and diastolic blood pressure (DBP) alone and during the extended tasks (all ps < .00001/.00001). BH had larger SBP and DBP increases over all postcaffeine periods (ps < .04/04) and larger DBP rises to the extended tasks after caffeine (p = .007). These combined effects led to undesirably high BPs (> 140/82 mmHg) relative to controls (< 130/75) during the 100 min after caffeine intake. Caffeine taken by BH at times of extended behavioral stress may elevate BP to a clinically meaningful degree. This research was supported by the Medical Research Service of the Department of Veterans Affairs and the National Heart Lung and Blood Institute of the National Institutes of Health, grant numbers HL32050 and HL07640. We thank Barbara McKey and Judith Silverstein for their efforts in data collection and Terrie Thomas for her valuable comments on an earlier version of this article.