Elizabeth C. D. Gullette

Effects of Exercise and Weight Loss on Mental Stress–Induced Cardiovascular Responses in Individuals With High Blood Pressure

The purpose of this study was to determine the effects of exercise and weight loss on cardiovascular responses during mental stress in mildly to moderately overweight patients with elevated blood pressure. Ninety-nine men and women with high normal or unmedicated stage 1 to stage 2 hypertension (systolic blood pressure 130 to 179 mm Hg, diastolic blood pressure 85 to 109 mm Hg) underwent a battery of mental stress tests, including simulated public speaking, anger recall interview, mirror trace, and cold pressor, before and after a 6-month treatment program. Subjects were randomly assigned to 1 of 3 treatments: (1) aerobic exercise, (2) weight management combining aerobic exercise with a behavioral weight loss program, or (3) waiting list control group. After 6 months, compared with control subjects, participants in both active treatment groups had lower levels of systolic blood pressure, diastolic blood pressure, total peripheral resistance, and heart rate at rest and during mental stress. Compared with subjects in the control group, subjects in the exercise and weight management groups also had greater resting stroke volume and cardiac output. Diastolic blood pressure was lower for the weight management group than for the exercise-only group during all mental stress tasks. These results demonstrate that exercise, particularly when combined with a weight loss program, can lower both resting and stress-induced blood pressure levels and produce a favorable hemodynamic pattern resembling that targeted for antihypertensive therapy.

Biobehavioral Approaches to the Treatment of Essential Hypertension

Despite recent advances in the medical management of hypertension, chronically elevated blood pressure remains a major health problem in the United States, affecting almost 50 million Americans. It is widely recognized that lifestyle factors contribute to the development and maintenance of elevated blood pressure. This article critically reviews current approaches to the nonpharmacological treatment of high blood pressure and highlights outcome studies of exercise, weight loss and dietary modification, and stress management and relaxation therapies. Methodological issues in the assessment and treatment of hypertension are discussed, along with possible mechanisms by which lifestyle modification may reduce elevated blood pressure.

Effects of exercise and weight loss on blood pressure during daily life.

PURPOSE The objective of this study was to investigate the effects of exercise training and weight loss on blood pressure (BP) associated with physical activity and emotional stress during daily life. METHODS One hundred twelve participants with unmedicated high normal or stage 1 to stage 2 hypertension were randomized to one of three conditions: a combined exercise and behavioral weight management group (WM), an exercise-only group (EX), or a wait list control group (CON). BP was assessed in the clinic and during 15 h of daytime ambulatory BP monitoring at baseline and after 6 months of treatment. RESULTS Increased levels of physical activity and emotional distress measured during daily life were associated with increases in systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), and rate pressure product (RPP). After treatment, the WM group had significantly lower DBP, HR, and RPP responses during both high and low levels of physical activity and emotional distress compared with the CON group. The EX group had similar BP levels as the WM group, although the EX group had significantly lower BP than the CON group during low but not high levels of physical activity and emotional distress. CONCLUSION These findings indicate that exercise, especially when combined with weight loss, reduces BP levels at rest and in situations that typically elevate BP such as intense physical activity and emotional distress.

Relationship of clinic, ambulatory, and laboratory stress blood pressure to left ventricular mass in overweight men and women with high blood pressure.

Objective This study was designed to evaluate the relationship between left ventricular (LV) mass and blood pressure (BP) recorded in the following contexts: in the clinic, using standard auscultatory procedures, during a typical day using ambulatory BP monitoring, and in the laboratory environment during behavioral stress testing. Methods Ninety-seven men and women with clinic systolic blood pressure (SBP) of 130 to 180 mm Hg and/or diastolic blood pressure (DBP) of 85 to 110 mm Hg and mild to moderate obesity were included in the study. Laboratory stressors included the following tasks: Public Speaking; Anger Interview; Mirror Trace; and Cold Pressor. LV mass was measured using echocardiography and adjusted for body size by dividing by height2.7 to yield LV mass index (LVMI). Results LVMI was positively correlated with clinic SBP (r = 0.24, p < .05), ambulatory SBP (r = 0.34, p < .01), and aggregated laboratory stress SBP (r = 0.28, p < .01). Of the individual stressors, only SBP responses to the Mirror Trace and Cold Pressor tasks were independently correlated with LVMI (r = 0.35 and 0.34, respectively, p values < .01). Hierarchical regression analyses revealed that laboratory stress SBP remained a significant predictor of LVMI, after controlling for BMI and clinic pressure. Conclusions These findings suggest that cardiovascular responses to behavioral stress are associated with individual differences in LVMI in men and women with high blood pressure who are overweight. Laboratory studies of behavioral stress may help promote our understanding of the pathophysiology of LVH.

Relationship between exercise systolic blood pressure and left ventricular geometry in overweight, mildly hypertensive patients.

Objective To examine the association between the graded exercise systolic blood pressure (SBP) response and left ventricular (LV) geometric structure in patients with untreated mild hypertension. Participants The study included 80 sedentary, overweight patients (43 female and 37 male) with unmedicated high normal blood pressure or stage 1–2 hypertension. Methods An echocardiogram was used to determine LV mass and the relative wall thickness (RWT) in relation to the chamber dimension. Participants performed a maximal graded exercise test, and the SBP was recorded at workloads of 2, 4 and 6 metabolic equivalents and at peak exercise. Separate statistical models were used to determine the influence of LV mass indexed for height2.7 (LVMIh) and RWT on submaximal exercise SBP and peak exercise SBP, controlling for resting SBP, age, gender, ethnicity and body mass index. Results A greater RWT was associated with a higher submaximal SBP level (P = 0.038). Neither LVMIh (P = 0.989) nor the interaction of RWT and LVMIh (P = 0.787) were related to the submaximal SBP. None of the main or interaction effects of RWT and LVMIh were associated with the peak exercise SBP level. Conclusion Increases in RWT were associated with higher submaximal exercise SBP responses in a sample of overweight, unmedicated hypertensives. These results suggest that RWT is an important determinant of the association between cardiac mass and exercise SBP response.

Predicting peak oxygen uptake among older patients with chronic illness.

PURPOSE To compare three equations developed to predict VO2 among patients diagnosed with one of two chronic diseases: essential hypertension (HTN), and fibromyalgia (FM). The equations included the American College of Sports Medicine (ACSM) equation, the FAST equation developed from the Fitness and Arthritis in Seniors Trial (FAST), and an equation developed by Foster et al. METHODS One hundred twenty-two HTN subjects and 68 FM subjects completed a maximum exercise test according to the Duke/Wake Forest protocol. Measured peak VO2 was then compared with the VO2 predicted by the ACSM, FAST and FOSTER equations, using several statistical methods. RESULTS The ACSM equation overpredicted peak VO2 in the HTN group by 10.0 +/- 4.0 mL/kg-1/min-1, and in the FM group by 8.6 +/- 4.9 mL/kg-1/min-1 (P < 0.0001). The FAST equation, however, underestimated peak VO2 by 1.5 +/- 4.2 mL/kg-1/min-1 (P < 0.01) and 1.0 +/- 3.3 mL/kg-1/min-1 (P < 0.0001) in the HTN and FM groups, respectively. The FOSTER equation overestimated peak VO2 by 2.3 +/- 3.6 mL/kg-1/min-1 in the HTN group and by 2.1 +/- 3.5 mL/kg-1/min-1 in the FM group (P < 0.0001). A large degree of variability was found for each of the equations. CONCLUSION Results of this investigation indicate that all three equations produced peak VO2 values that were statistically different from measured values. Although the ACSM equation overestimated VO2 by more than 2 metabolic equivalents (METs) in each patient group, both the FAST and FOSTER equations produced differences that were less than 1 MET. Further research is needed to examine the FAST and FOSTER equations among other patient populations and with other exercise protocols.