Demetra D. Christou

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BACKGROUND Obesity may alter vascular endothelial cell protein expression (VECPE) of molecules that influence susceptibility to atherosclerosis. METHODS AND RESULTS Quantitative immunofluorescence was performed on vascular endothelial cells collected from 108 men and women free of clinical disease who varied widely in adiposity (body mass index 18.4 to(More)
BACKGROUND Short-term and tonic regulation of arterial blood pressure (BP) differ in premenopausal women and men of similar age. The autonomic nervous system (ANS) plays a critical role in BP regulation. METHODS AND RESULTS To test the hypothesis that women have lower tonic ANS support of BP (reduction in intra-arterial BP during acute ganglionic blockade(More)
Background—The prevalence of cardiovascular disease (CVD) is partly attributable to an inactive and/or overweight population. However, the independent association of body fatness and aerobic fitness with CVD risk factors is uncertain. We sought to determine whether fatness or fitness better predicted traditional CVD risk factors in men with broad fatness,(More)
AIMS Chronic heart failure (CHF) causes inspiratory (diaphragm) muscle weakness and fatigue that contributes to dyspnoea and limited physical capacity in patients. However, the mechanisms that lead to diaphragm dysfunction in CHF remain poorly understood. Cytokines and angiotensin II are elevated in CHF and stimulate the activity of the enzyme(More)
BACKGROUND Baroreflex buffering is an important mechanism in arterial blood pressure control. The effect of healthy (physiological) aging on tonic baroreflex buffering in humans is unknown. METHODS AND RESULTS Baroreflex buffering was determined in 27 young (aged 25+/-1 years) and 16 older (aged 65+/-1 years) healthy normotensive men by measuring the(More)
Cardiovascular aging is associated with a decline in the function of the vascular endothelium. Considerable evidence indicates that age-induced impairment of endothelium-dependent vasodilation results from a reduction in the availability of nitric oxide (NO(•) ). NO(•) can be scavenged by reactive oxygen species (ROS), in particular by superoxide radical(More)
A decrease in maximal exercise heart rate (HR(max)) is a key contributor to reductions in aerobic exercise capacity with aging. However, the mechanisms involved are incompletely understood. We sought to gain insight into the respective roles of intrinsic heart rate (HR(int)) and chronotropic beta-adrenergic responsiveness in the reductions in HR(max) with(More)
Obesity increases linearly with age and is associated with impaired vascular endothelial function and increased risk of cardiovascular disease. MRs (mineralocorticoid receptors) contribute to impaired vascular endothelial function in cardiovascular disease; however, their role in uncomplicated human obesity is unknown. Because plasma aldosterone levels are(More)
Background—Obesity may alter vascular endothelial cell protein expression (VECPE) of molecules that influence susceptibility to atherosclerosis. Methods and Results—Quantitative immunofluorescence was performed on vascular endothelial cells collected from 108 men and women free of clinical disease who varied widely in adiposity (body mass index 18.4 to 36.7(More)
Diaphragm muscle weakness in chronic heart failure (CHF) is caused by elevated oxidants and exacerbates breathing abnormalities, exercise intolerance, and dyspnea. However, the specific source of oxidants that cause diaphragm weakness is unknown. We examined whether mitochondrial reactive oxygen species (ROS) cause diaphragm weakness in CHF by testing the(More)