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

Exercise blood pressure and cardiac structure: A systematic review and meta-analysis of cross-sectional studies

OBJECTIVES

A hypertensive response to exercise (HRE) is associated with cardiovascular disease and high blood pressure (BP). Sub-clinical changes to cardiac structure may underlie these associations, although this has not been systematically determined. Via systematic review and meta-analysis, we aimed to (1) assess the relationship between exercise BP and cardiac structure, and (2) determine if cardiac structure is altered in those with an HRE, across various study populations (including those with/without high BP at rest).

DESIGN AND METHODS

Three online databases were searched for cross-sectional studies reporting exercise BP, HRE and cardiac structural variables. Random-effects meta-analyses and meta-regressions were used to calculate pooled correlations between exercise BP and cardiac structure, and pooled mean differences and relative risk between those with/without an HRE.

RESULTS

Forty-nine studies, (n=23,707 total; aged 44±4 years; 63% male) were included. Exercise systolic BP was associated with increased left ventricular (LV) mass, LV mass index, relative wall thickness, posterior wall thickness and interventricular septal thickness (p<0.05 all). Those with an HRE had higher risk of LV hypertrophy (relative risk: 2.6 [1.85-3.70]), increased LV mass (47±7g), LV mass index (7±2g/m²), relative wall thickness (0.02±0.005), posterior wall thickness (0.78±0.20mm), interventricular septal thickness (0.78±0.17mm) and left atrial diameter (2±0.52mm) vs. those without an HRE (p<0.05 all). Results were broadly similar between studies with different population characteristics.

CONCLUSIONS

Exercise systolic BP is associated with cardiac structure, and those with an HRE show evidence towards adverse remodelling. Results were similar across different study populations, highlighting the hypertension-related cardiovascular risk associated with an HRE.

Body composition influences blood pressure during submaximal graded test in women

This study aimed to determine whether body composition affected cardiovascular responses of normal, overweight and obese women by comparing heart rate (HR) and blood pressure (BP) during a graded submaximal treadmill exercise. Thirty five healthy non-smoking, premenopausal women (age 30.8 ± 9.5 yr; height 1.66 ± 0.05 m; weight 73.8 ± 18.9 kg; body fat 36.2 ± 9.5%; maximum oxygen uptake 33.5 ± 8.1 mL·min·kg^-1) volunteered for this study, and were classified into three groups based on BMI: normal weight (NOR; ≤24.9 kg·m²), overweight (OVW; 25-29.9 kg·m²) and obese (OBE; ≥30 kg·m²). Participants performed a submaximal graded test at 30%, 40%, 50% and 60% of maximal oxygen uptake, during which HR, systolic BP (SBP), diastolic BP (DBP) and mean arterial pressure (MAP) were measured. At rest, participants of OBE group had higher BP than NOR and OVW. During the submaximal graded test, HR, SBP and MAP increased as a function of intensity. There were no group differences in HR, but greater SBP, DBP and MAP in OBE compared to NOR and OBW at all intensities except 60%. Overall, our study further contributes to underscore the importance of stress testing specifically to evaluate the increased risks apparently healthy obese women are placed at to developing diseases from the chronic exposure to raised BP, despite normal resting BP and HR responses during exercise.

Exercise Hypertension

Irrespective of apparent 'normal' resting blood pressure (BP), some individuals may experience an excessive elevation in BP with exercise (i.e. systolic BP ≥210 mm Hg in men or ≥190 mm Hg in women or diastolic BP ≥110 mm Hg in men or women), a condition termed exercise hypertension or a 'hypertensive response to exercise' (HRE). An HRE is a relatively common condition that is identified during standard exercise stress testing; however, due to a lack of information with respect to the clinical ramifications of an HRE, little value is usually placed on such a finding. In this review, we discuss both the clinical importance and underlying physiological contributors of exercise hypertension. Indeed, an HRE is associated with an increased propensity for target organ damage and also predicts the future development of hypertension, cardiovascular events and mortality, independent of resting BP. Moreover, recent work has highlighted that some of the elevated cardiovascular risks associated with an HRE may be related to high-normal resting BP (pre-hypertension) or ambulatory 'masked' hypertension and that an HRE may be an early warning signal of abnormal BP control that is otherwise undetected with clinic BP. Whilst an HRE may be amenable to treatment via pharmacological and lifestyle interventions, the exact physiological mechanism of an HRE remains elusive, but it is likely a manifestation of multiple factors including large artery stiffness, increased peripheral resistance, neural circulatory control and metabolic irregularity. Future research focus may be directed towards determining threshold values to denote the increased risk associated with an HRE and further resolution of the underlying physiological factors involved in the pathogenesis of an HRE.

Exaggerated exercise blood pressure response is related to tissue Doppler imaging estimated diastolic dysfunction in the early stages of hypertension

We investigated the plausible interrelationship of exaggerated blood pressure response (EBPR) during exercise with left ventricular (LV) diastolic dysfunction, both associated with adverse cardiovascular outcomes, in the early stages of essential hypertension (EH). Sixty-five consecutive patients (aged 54 years, 56 males) with stage I to II EH underwent 24-hour ambulatory blood pressure (BP) recording and treadmill exercise testing and were classified as subjects with (n = 21) and without EBPR (n = 44) based on the systolic BP elevation at peak exercise (>/=210 mm Hg for men and >/=190 mm Hg for women). LV diastolic function was estimated by pulsed tissue Doppler imaging (TDI), averaging diastolic mitral annular velocities (Em, Am) from four separate sites (LV lateral, septal, anterior, and inferior wall). Hypertensives with EBPR, compared with those without EBPR, exhibited increased 24-hour pulse pressure by 4.8 mm Hg (P < .05) and significantly lower values of Em/Am ratio by 0.07 (P < .05). Univariate logistic regression analysis revealed that only 24-hour pulse pressure (odds ratio [OR] = 1.069; P = .043) and Em/Am (OR = 0.041; P = .049) were independent predictors of EBPR. Hypertensives with EBPR compared to their counterparts without EBPR are characterized by more pronounced LV diastolic dysfunction - assessed by TDI. Moreover, the increased pulsatile load seems to be a common denominator of these hypertension-linked states.

Cardiac allograft hypertrophy is associated with impaired exercise tolerance after heart transplantation

BACKGROUND

Exercise performance, an important aspect of quality of life, remains limited after heart transplantation (HTx). This study examines the effect of cardiac allograft remodeling on functional capacity after HTx.

METHODS

The total cohort of 117 HTx recipients, based on echocardiographic determination of left ventricle mass and relative wall thickness at 1 year after HTx, was divided into 3 groups: (1) NG, normal geometry; (2) CR, concentric remodeling; and (3) CH, concentric hypertrophy. Cardiopulmonary exercise testing was performed 5.03 ± 3.08 years after HTx in all patients. Patients with acute rejection or significant graft vasculopathy were excluded.

RESULTS

At 1 year post-HTx, 30% of patients had CH, 55% had CR and 15% had NG. Exercise tolerance, measured by maximum achieved metabolic equivalents (4.62 ± 1.44 vs 5.52 ± 0.96 kcal/kg/h), normalized peak Vo(2) (52 ± 14% vs 63 ± 12%) and Ve/Vco(2) (41 ± 17 vs 34 ± 6), was impaired in the CH group compared with the NG group. A peak Vo(2) ≤14 ml/kg/min was found in 6%, 22% and 48% of patients in the NG, CR and CH groups, respectively (p = 0.01). The CH pattern was associated with a 7.4-fold increase in relative risk for a peak Vo(2) ≤14 ml/kg/min compared with NG patients (95% confidence interval 1.1 to 51.9, p = 0.001). After multivariate analysis, a 1-year CH pattern was independently associated with a reduced normalized peak Vo(2) (p = 0.018) and an elevated Ve/Vco(2) (p = 0.035).

CONCLUSIONS

The presence of CH at 1 year after HTx is independently associated with decreased normalized peak Vo(2) and increased ventilatory response in stable heart transplant recipients. The identification of CH, a potentially reversible mechanism of impairment in exercise capacity after HTx, may have major clinical implications.

The role of mood disorders in exercise-induced cardiovascular reactivity

OBJECTIVE

Increased cardiovascular (CV) reactivity has been associated with worse CV prognosis. Though mood disorders (MDs) have been associated with increased CV reactivity during behavioral stressors, the extent to which MDs and their interaction with coronary heart disease (CHD) influences exercise-induced CV reactivity has not been evaluated.

METHODS

Five hundred twenty-six patients underwent nuclear exercise stress testing. Cardiovascular parameters were assessed at rest, every 2 minutes during exercise, and at peak exercise. MDs were measured using a structured psychiatric interview, the Primary Care Evaluation of Mental Disorders, and CHD was defined as having a history of myocardial infarction, revascularization, heart failure, and/or cerebrovascular event.

RESULTS

CHD patients exhibited lower peak exercise heart rate (F = 9.40, p = .002) compared with patients without CHD. Submaximal data showed that patients with CHD had a slower rate of increase of heart rate (F = 4.29, p = .04) and diastolic blood pressure (F = 3.27, p = .04). There was an interaction of CHD and MDs, indicating that in patients with CHD, the rate of submaximal increase in systolic blood pressure (F = 3.08, p = .047) and rate-pressure product (F = 5.13, p = .006) was greater in patients with a MD compared with those without a MD. These differences were not observed in patients with no CHD. No other main or interaction effects of MDs and CHD were observed.

CONCLUSION

Though MDs alone do not seem to be associated with higher levels of stress CV reactivity, their combination with CHD leads to increased submaximal exercise-induced CV reactivity. Prospective studies are needed to explore the causal relationship between these variables.

Exercise blood pressure response, albuminuria, and arterial stiffness in hypertension

BACKGROUND

A hypertensive response to exercise is associated with high cardiovascular risk, whereas the data about its relation to surrogates of subclinical atherosclerosis are scarce. We investigated the relationships of a hypertensive response to exercise with urinary albumin excretion and arterial stiffness in hypertensives.

METHODS

There were 171 untreated males (mean age 52 years, all Caucasian) with stage I-II essential hypertension and a negative treadmill exercise test divided into those with a hypertensive response to exercise (n=48) (peak exercise systolic blood pressure > or =210 mm Hg) and to those with normal blood pressure response (n=123). Albumin-to-creatinine ratio values were determined as the mean of 3 nonconsecutive morning spot urine samples, and arterial stiffness was evaluated on the basis of carotid-to-femoral pulse wave velocity.

RESULTS

Patients with a hypertensive response to exercise compared with those with normal blood pressure response exhibited greater log albumin-to-creatinine ratio (1.52+/-0.59 vs 0.97+/-0.33 mg/g) and higher pulse wave velocity (8.7+/-1.6 vs 7.7+/-1.2 m/s), independent of potentially confounding demographic and clinical factors. Resting systolic blood pressure (odds ratio [OR] 1.11, 95% confidence interval [CI], 1.06-1.16), body mass index (OR 1.12, 95% CI, 1.02-1.23), resting heart rate (OR 0.96, 95% CI, 0.93-0.99), and albumin-to-creatinine ratio (OR 7.45, 95% CI, 2.54-21.83) were independently associated with a hypertensive response to exercise.

CONCLUSION

A hypertensive response to exercise is related to augmented albumin-to-creatinine ratio and arterial stiffness, reflecting accelerated subclinical atherosclerosis. The association of albumin excretion with exercise blood pressure response suggests that albuminuria constitutes an important factor in the interpretation of the hypertensive response to exercise-associated risk.

Endothelial nitric oxide synthase Glu298Asp gene polymorphism is associated with hypertensive response to exercise in well-controlled hypertensive patients

PURPOSE

Hypertensive response to exercise (HRE) is known to be an adverse prognostic factor for future cardiovascular events and may be associated to endothelial dysfunction. Previous studies regarding endothelial nitric oxide synthase (eNOS) Glu298Asp polymorphism focused upon its relation to hypertension. In this study, we hypothesize that the polymorphism may be associated with inherent difference in endothelial response to exercise.

PATIENTS AND METHODS

Two hundred sixty nine patients who underwent treadmill test were enrolled in this study; 77 patients (mean age 55.8 +/- 9.4 years) had hypertensive response (peak systolic BP of > or = 210 mmHg in men and > or = 190 mmHg in women). Pulse wave velocity (PWV) was measured on 153 patients of them. The Glu298Asp exchange in exon 7 was determined by the methods of single base extension with amplifying primers and probes for TaqMan.

RESULTS

The percentages of the GG, GT and TT genotypes were 81.0, 18.6 and 0.4 %, respectively. The presence of GT or TT genotype was independently associated with prevention of HRE when controlled for age, sex, baseline systolic BP and homeostatic model assessment (HOMA) index (OR=0.35, p=0.016). Subgroup analysis showed that preventive effect for HRE of T allele was significant in females (p < 0.001) and patients without insulin resistance (p=0.009).

CONCLUSION

In our study, eNOS Glu298Asp polymorphism was significantly associated with HRE. This result suggests that the presence of T allele of the Glu298Asp polymorphism may be a favorable factor to in preventing HRE, especially in female and patients without insulin resistance.

Insulin resistance is associated with hypertensive response to exercise in non-diabetic hypertensive patients

AIM

Insulin resistance is associated with increased sympathetic activity and elevated angiotensin II which may contribute to the excessive increase in arterial blood pressure during exercise. In this study, we hypothesized that increased insulin resistance will be significantly associated with hypertensive response to exercise (HRE) in non-diabetic hypertensive patients.

METHOD

Two hundred seventy-five hypertensive patients were included in this study. HOMA-IR index using serum fasting glucose and insulin was calculated for insulin resistance. There were 79 patients with hypertensive response (age 56.1+/-9.4 years) and 196 patients without hypertensive response (age 53.9+/-8.9 years).

RESULTS

Insulin resistance, assessed by HOMA index, was significantly higher in hypertensive response group as compared to control (HOMA=2.60+/-1.54 versus 1.76+/-0.86, P<0.001). HOMA was an independent predictor of HRE when controlled for age, sex, BMI and baseline SBP (odds ratio=2.008, P<0.001). Also, HOMA was significantly correlated with the magnitude of SBP elevation controlled for age, sex, BMI and baseline SBP as well (beta=0.293, P<0.001). In conclusion, this study shows that insulin resistance is a significant determinant of hypertensive response to exercise. Further studies to determine the prognostic significance of this finding is warranted.

Association between exercise capacity and left ventricular geometry in overweight patients with mild systemic hypertension

The purpose of this study was to determine the relation between left ventricular (LV) geometry and exercise capacity in unmedicated, hypertensive patients. Analysis of the data revealed peak oxygen consumption (ml kg(-1) min(-1)) for concentric hypertrophy (corrected mean +/- SE 23.5 +/- 1.2) was significantly less (F = 3.68, p <0.02) than the concentric remodeling (28.1 +/- 1.2) and normal (27.3 +/- 0.6) geometries. The LV geometric pattern was found to be associated with exercise capacity in unmedicated, hypertensive patients, such that patients with concentric hypertrophy showed reduced capacity.