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Biomedical subjects

Thomas G Pickering

Publications and source records attributed to Thomas G Pickering.

At least 37 records · Page 2Linked to original sources
PubMed2006

The Japan Morning Surge-1 (JMS-1) study: protocol description.

Morning blood pressure is reported to be more closely related to hypertensive organ damages such as left ventricular mass index, microalbuminuria and silent cerebral infarcts, than blood pressure at other times of the day. Morning blood pressure may play an important role in the pathogenesis of hypertensive target organ damage. Increased sympathetic nerve activity is reported to be one of the mechanisms of morning hypertension; however, there are no available data that show whether strict home blood pressure control, especially in the morning period, can reduce target organ damage. The Japan Morning Surge-1 (JMS-1) study includes hypertensive outpatients with elevated morning systolic blood pressure (>or=135 mmHg) as assessed by self-measured blood pressure monitoring at home. All enrolled patients are under stable antihypertensive medication status. Exclusion criteria are arrhythmia, chronic inflammatory disease, and taking alpha-blockers or beta-blockers. The target number of patients to be enrolled in the JMS-1 study is 600, and the aim is to evaluate differences in the markers of hypertensive target organ damage, such as brain natriuretic peptide and the urinary albumin excretion/creatinine ratio. All of the patients are randomized to an experimental group or a control group, with randomization to be carried out by telephone interviews with the patients' physicians. In the experimental group, patients begin taking additional antihypertensive medication just before going to bed. This consists of doxazosin 1 mg/day, which then is increased to 2 mg/day and 4 mg/day, with a beta-blocker added after a 1-month interval until the morning systolic blood pressure is controlled to less than 135 mmHg. Patients in the control group continue the treatment they are receiving at the enrollment for 6 months. Blood pressure levels, adverse effects, and hypertensive target organ damage before and after the study are evaluated. In the JMS-1 study, we will evaluate whether strict morning blood pressure control by sympathetic nervous system blockade using an alpha-blocker, doxazosin, and with the addition of a beta-blocker if needed, can reduce hypertensive target organ damage.

Albuminuria↗
PubMed2006

Morning hypertension: the strongest independent risk factor for stroke in elderly hypertensive patients.

Stroke occurs most frequently in the morning hours, but the impact of the morning blood pressure (BP) level on stroke risk has not been fully investigated in hypertensives. We studied stroke prognosis in 519 older hypertensives in whom ambulatory BP monitoring was performed, and who were followed prospectively. During an average duration of 41 months (range: 1-68 months), 44 stroke events occurred. The morning systolic BP (SBP) was the strongest independent predictor for stroke events among clinic, 24-h, awake, sleep, evening, and pre-awake BPs, with a 10 mmHg increase in morning SBP corresponding to a relative risk (RR) of 1.44 (p<0.0001). The average of the morning and evening SBP (Av-ME-SBP; 10 mmHg increase: RR=1.41, p=0.0001), and the difference between the morning and evening SBP (Di-ME-SBP; 10 mmHg increase: RR=1.24, p=0.0025) were associated with stroke risks independently of each other. The RR of morning hypertension (Av-ME-SBP > or = 135 mmHg and Di-ME-SBP > or = 20 mmHg) vs. sustained hypertension (Av-ME-SBP > = 135 mmHg and Di-ME-SBP < or = 20 mmHg) for stoke events was 3.1 after controlling for other risk factors (p=0.01). In conclusion, morning hypertension is the strongest independent predictor for future clinical stroke events in elderly hypertensive patients, and morning and evening BPs should be monitored in the home as a first step in the treatment of hypertensive patients.

Aged↗
PubMed2005

Depressive symptoms are independently predictive of carotid atherosclerosis.

The investigators tested whether depressive symptoms were predictive of carotid atherosclerosis, a marker of coronary atherosclerosis. Healthy participants (n = 219) underwent the baseline assessment of cardiovascular risk factors, including self-reported depressive symptoms, and were assessed for carotid plaque at 10-year follow-up. Adjusting for baseline cardiovascular risk factors, participants with elevated depression scores at baseline were >2 times as likely as those with no depressive symptoms to have carotid plaque.

Adult↗
PubMed2005

Age-dependent associations between sleep-disordered breathing and hypertension: importance of discriminating between systolic/diastolic hypertension and isolated systolic hypertension in the Sleep Heart Health Study.

BACKGROUND: Sleep-disordered breathing (SDB) is associated with hypertension in the middle-aged. The association is less clear in older persons. Most middle-aged hypertensives have systolic/diastolic hypertension, whereas isolated systolic hypertension (ISH) is common among persons over 60 years. Mechanistically, only systolic/diastolic hypertension is expected to be associated with SDB, but few studies of SDB and hypertension distinguish systolic/diastolic hypertension from ISH. Prior investigations may have underestimated an association between SDB and systolic/diastolic hypertension in the elderly by categorizing individuals with ISH as simply hypertensive. METHODS AND RESULTS: We conducted cross-sectional analyses of 6120 participants in the Sleep Heart Health Study, stratified by age: 40 to 59 (n=2477) and > or =60 years. Outcome measures included apnea-hypopnea index (AHI; average number of apneas plus hypopneas per hour of sleep), systolic/diastolic hypertension (> or =140 and > or =90 mm Hg), and ISH (> or =140 and <90 mm Hg). With adjustment for covariates, ISH was not associated with SDB in either age category. In those aged<60 years, AHI was significantly associated with higher odds of systolic/diastolic hypertension (AHI 15 to 29.9, OR=2.38 [95% CI 1.30 to 4.38]; AHI > or =30, OR=2.24 [95% CI 1.10 to 4.54]). Among those aged > or =60 years, no adjusted association between AHI and systolic/diastolic hypertension was found. CONCLUSIONS: SDB is associated with systolic/diastolic hypertension in those aged <60 years. No association was found between SDB and systolic/diastolic hypertension in those aged > or =60 years or between SDB and ISH in either age category. These findings have implications for SDB screening and treatment. Distinguishing between hypertensive subtypes reveals a stronger association between SDB and hypertension for those aged <60 years than previously reported.

Adult↗
PubMed2005

Recommendations for blood pressure measurement in humans and experimental animals: part 1: blood pressure measurement in humans: a statement for professionals from the Subcommittee of Professional and Public Education of the American Heart Association Council on High Blood Pressure Research.

Accurate measurement of blood pressure is essential to classify individuals, to ascertain blood pressure-related risk, and to guide management. The auscultatory technique with a trained observer and mercury sphygmomanometer continues to be the method of choice for measurement in the office, using the first and fifth phases of the Korotkoff sounds, including in pregnant women. The use of mercury is declining, and alternatives are needed. Aneroid devices are suitable, but they require frequent calibration. Hybrid devices that use electronic transducers instead of mercury have promise. The oscillometric method can be used for office measurement, but only devices independently validated according to standard protocols should be used, and individual calibration is recommended. They have the advantage of being able to take multiple measurements. Proper training of observers, positioning of the patient, and selection of cuff size are all essential. It is increasingly recognized that office measurements correlate poorly with blood pressure measured in other settings, and that they can be supplemented by self-measured readings taken with validated devices at home. There is increasing evidence that home readings predict cardiovascular events and are particularly useful for monitoring the effects of treatment. Twenty-four-hour ambulatory monitoring gives a better prediction of risk than office measurements and is useful for diagnosing white-coat hypertension. There is increasing evidence that a failure of blood pressure to fall during the night may be associated with increased risk. In obese patients and children, the use of an appropriate cuff size is of paramount importance.

Adult↗
PubMed2005

Sustained blood pressure increase after an acute stressor: the effects of the 11 September 2001 attack on the New York City World Trade Center.

BACKGROUND: Effects of catastrophic stress on blood pressure are well documented, but usually few measurements were taken before the event occurred, and the people studied were directly involved or geographically close to the disaster. The impact of the 11 September 2001 (9/11) attacks in New York City had far greater reach, and has been sustained by subsequent events. OBJECTIVE: To test the hypothesis that, after the 9/11 attacks, blood pressures in the population affected would be increased compared with that in both the preceding months and the same period during the previous year. METHODS: We used data available from a current study of blood pressure in four sites in the USA that enabled us to examine them from two perspectives: a mixed (within and between groups) analysis that tested the overall differences in blood pressure before and after 9/11, and a within-subjects model to examine the more focused issue of individual change in blood pressure after 9/11. The blood pressures of 427 hypertensive individuals were telemonitored at four sites. An additional 101 patients had been monitored at two sites during the same period in the previous year. RESULTS: Mean systolic blood pressure was significantly greater during the 2 months after 9/11, across the four sites, compared with that assessed during the previous 2 months (range of observed differences 1.7-3.8 mmHg). At the two sites for which data were available for the same period in the year 2000, there was also a significant effect for the same period during the preceding year for systolic blood pressure. However, at both these sites the effect at 2000 was significantly smaller than the effect at 2001. Blood pressure also generally increased among those individuals in whom monitoring overlapped the 9/11 event. CONCLUSION: The World Trade Center attacks produced a substantial and sustained increase in blood pressure that appears to be independent of seasonal effects, and which has important implications for morbidity and financial burden. The ubiquitous continuing reference to the events in the news reports may contribute to the sustained effects.

Blood Pressure↗
PubMed2005

Anxiety and outcome expectations predict the white-coat effect.

OBJECTIVE: To determine whether elevated clinic blood pressure compared with daytime ambulatory blood pressure, referred to as the white-coat effect, is associated with anxiety and increased blood pressure expectancy in the doctor's office. METHODS: The 24-h ambulatory blood pressure measurements and physicians' blood pressure measurements were obtained in 226 normotensive and hypertensive study participants. Anxiety levels were assessed multiple times during the clinic visit using a Visual Analog Scale. Participants' expectations regarding the clinic visit were assessed using a six-item scale (Expectations of Outcomes Scale). The white-coat effect was computed as the difference between the mean clinic blood pressure and the mean daytime ambulatory blood pressure. Multiple regression analysis was performed to examine the association between anxiety, outcome expectations and the white-coat effect, adjusting for age, sex, and ambulatory blood pressure level. RESULTS: As predicted, outcome expectations and anxiety during the clinic visit were significantly associated with the white-coat effect. Results of the regression analysis indicated that only expectancy had an independent effect on the systolic white-coat effect; however, both anxiety and expectancy had independent effects on the diastolic white-coat effect. CONCLUSION: Our results provide empirical support to the hypothesis that anxiety and blood pressure expectancy may elevate clinic blood pressure.

Adolescent↗
PubMed2005

A comparison of morning blood pressure surge in African Americans and whites.

African Americans have twice the risk of suffering a stroke compared to whites, but the reasons for this disparity have yet to be elucidated. Recent data suggest that the morning blood pressure (BP) surge is an independent predictor of strokes. Whether African Americans and whites differ with respect to morning BP surge is unknown. African-American (n=183) and white (n=139) participants, age 18-65, were studied with 24-hour ambulatory BP monitoring. Morning surge was defined as morning BP minus the trough BP during sleep. The morning surge was significantly lower in African Americans than in whites (23 mm Hg vs. 27 mm Hg; both SEM=1.0; p=0.009). This relationship was no longer evident after adjusting for gender, age, and body mass index (23 mm Hg vs. 26 mm Hg; SE=1.0 and 1.1; p=nonsignificant). Morning BP surge is unlikely to account for differences in stroke incidence between African Americans and whites.

Adolescent↗