Subclinical atherosclerosis is related to injury level but not to inflammatory parameters in spinal cord injury subjects

STUDY DESIGN

Cross-sectional.

OBJECTIVES

Individuals with spinal cord injury (SCI) exhibit increased carotid intima-media thickness (IMT) and are reported to be exposed to higher circulating levels of inflammatory mediators. This study evaluated the relationship between inflammatory markers and carotid surrogates of cardiovascular risk in subjects with SCI.

SETTING

São Paulo, Brazil.

METHODS

A total of 65 nondiabetic, nonhypertensive, sedentary, nonsmoker men (34 with SCI; 31 healthy subjects) were evaluated by medical history, anthropometry, routine laboratory tests, analysis of hemodynamic, inflammatory parameters and ultrasound examination of carotid arteries.

RESULTS

Subjects with SCI (18 tetraplegic and 16 paraplegic) had lower systolic blood pressure (P = 0.009), higher serum C-reactive protein (P = 0.001), tumor necrosis factor (TNF) receptor-II (P = 0.02) and TNF receptor-I (P = 0.04) levels and increased in vitro production of interleukin-6 by mononuclear cells (P = 0.04), compared to able-bodied individuals. No differences in serum interleukin-6, e-selectin, intercellular adhesion molecule-1, vascular cell adhesion molecule-1 and transforming growth factor-β levels, or in vitro release of interleukin-10, interleukin-17 and interferon-γ by mononuclear cells, were detected between the studied groups. Common carotid IMT, but not internal carotid resistive index, was significantly higher in subjects with SCI (P<0.0001 adjusted for C-reactive protein and TNF receptor-II levels). In addition, tetraplegic subjects exhibited increased IMT (P = 0.002 adjusted for systolic blood pressure and body mass index), but similar levels of inflammatory mediators compared to paraplegic ones.

CONCLUSIONS

Individuals with SCI exhibit a clustering of vascular and inflammatory surrogates of increased cardiovascular risk. Nevertheless, subclinical carotid atherosclerosis is related to injury level but not to increased inflammatory status in these subjects.

Fitness and abdominal obesity are independently associated with cardiovascular risk

OBJECTIVES

To examine the relationship between cardiovascular fitness (VO(2)max) and abdominal obesity (waist circumference) and individual cardiovascular disease (CVD) risk factors, as well as a clustered risk factor profile, and to study the impact of gender, age and smoking on these relationships.

DESIGN

Cross-sectional.

SETTING

Astrand Laboratory of Work Physiology, Swedish School of Sport and Health Sciences, Stockholm, Sweden.

SUBJECTS

Men (n = 781) and women (n = 890) from two random population-based samples of Swedish women and men aged 20 to 65 years.

MAIN OUTCOMES

Odds ratios.

RESULTS

Each unit of higher fitness was associated with a decrease in all individual risk factors ranging from 2% to 4% independent of waist circumference, each unit of higher waist circumference was associated with an increased risk ranging from 2% to 5% independent of fitness. For clustering of three or more of the risk factors, each unit of fitness was associated with a 5% decrease in risk and each unit of waist circumference with a 5% increase in risk. The clustered risk was higher in unfit participants who were older or smoked daily, regardless of waist circumference. Obese participants were at higher risk if they were men or older, regardless of fitness level. However, neither a higher fitness level nor lean status reduced the risk associated with smoking.

CONCLUSIONS

Higher fitness and lower waist circumference are each independently associated to a similar extent with a lower CVD risk. Simultaneous evaluation of both fitness and abdominal obesity status in clinical practice is important.

The inverse association between cardiorespiratory fitness and C-reactive protein is mediated by autonomic function: a possible role of the cholinergic antiinflammatory pathway

Although studies have shown an inverse association between cardiorespiratory fitness (CRF) and C-reactive protein (CRP) levels, the underlying mechanisms are not fully understood. There is emerging evidence that autonomic nervous system function is related to CRP levels. Because high CRF is related to improved autonomic function, we hypothesized that the association between high CRF and low CRP levels would be affected by autonomic nervous system function. Cross-sectional analyses were conducted on 2,456 asymptomatic men who participated in a medical screening program. Fasting blood samples for cardiovascular disease risk factors were analyzed, and CRF was measured by maximal exercise treadmill test with expired gas analysis. We used an index of cardiac autonomic imbalance defined as the ratio of resting heart rate to 1 min of heart rate recovery after exercise (RHR/HRR). CRF was significantly correlated with CRP (r = -0.16, P < 0.05), and RHR/HRR (r = -0.48, P < 0.05), while RHR/HRR was significantly correlated with CRP (r = 0.25, P < 0.05). In multivariable linear regression models that adjusted for age, body mass index, smoking, disease status, medications, lipid profiles, glucose, and systolic blood pressure, CRF was inversely associated with CRP (beta = -0.09, P < 0.05). However, this relationship was no longer significant after adjusting for RHR/HRR in a multivariable linear regression model (beta = -0.03, P = 0.29). These results suggest that autonomic nervous system function significantly affects the relationship between CRF and inflammation in middle-aged men. Thus, physical activity or exercise training may favorably affect the cholinergic antiinflammatory pathway, but additional research is needed to confirm this finding.

Thromboxane prostanoid receptor activation impairs endothelial nitric oxide-dependent vasorelaxations: the role of Rho kinase

Activation of thromboxane prostanoid (TP) receptors causes potent vasoconstriction, which contributes to increased vascular tone and blood pressure. The present study examined the hypothesis that stimulation of TP receptor impaired endothelial nitric oxide-mediated vasorelaxation via a Rho kinase-dependent mechanism. The common carotid arteries of Sprague-Dawley rats were isolated and suspended in myograph for measurement of changes in isometric tension. The production of nitric oxide in primary cultured aortic endothelial cells was assayed with an imaging technique and phosphorylated levels of endothelial NOS were determined by Western blot analysis. 9,11-dideoxy-11alpha,9alpha-epoxy-methanoprostaglandin F(2alpha) (U46619) inhibited isoprenaline-induced relaxations in rings with or without endothelium. Treatment with Rho kinase inhibitors, Y27632 (2 microM) or HA 1077 (10 microM) prevented the effect of U46619 only in rings with endothelium while protein kinase C inhibitors were without effect. Rho kinase inhibitors did not affect isoprenaline-induced relaxations in endothelium-intact rings treated with L-NAME or 1H-[1,2,4]oxadizolo[4,3-a]quinoxalin-1-one (ODQ). Isoprenaline stimulated rises in nitric oxide (NO) production in cultured rat endothelial cells. The increased NO production was inhibited by U46619 (100 nM) and this effect was prevented by treatment with Y27632 but unaffected by the absence of extracellular calcium ions. U46619 attenuated isoprenaline-stimulated phosphorylation of eNOS, which was sensitive to inhibition by Y27632 and HA 1077. U46619-mediated effects were abolished by TP receptor antagonist, S18886 and the TP receptor was present in endothelial cells. The present results demonstrate that Rho kinase activation is likely to be the primary mechanism that underlies the U46619-stimulated TP-receptor-mediated inhibition of endothelial NO production and subsequent endothelium-dependent relaxations to isoprenaline.

Relationship between chronic pain and cognition in cognitively intact older persons and in patients with Alzheimer's disease. The need to control for mood

BACKGROUND

Brain areas that are involved in cognition and mood also play a role in pain processing.

OBJECTIVE

The goal of the present study was to examine the relationship between chronic pain and cognition [executive functions (EF) and memory], while controlling for mood, in cognitively intact older persons and in patients with Alzheimer's disease (AD).

METHODS

Two groups of subjects participated: 20 older persons without dementia and 19 patients in an early stage of probable AD who suffered from arthrosis/arthritis. Pain intensity and pain affect were assessed by the Colored Analogue Scale for Pain Intensity and for Pain Affect, the Faces Pain Scale (FPS) and the Number of Words Chosen-Affective (NWC-A). Level of depression and anxiety were evaluated by questionnaires. EF and memory were assessed by neuropsychological tests.

RESULTS

The results show that significant correlations between specific cognitive functions, pain intensity and pain affect were lacking in the cognitively intact older persons. Cognition, in particular memory, appeared to be related to depressive symptoms. In contrast, a significant positive correlation was observed between EF, pain intensity and pain affect measured by the FPS in the AD group.

CONCLUSIONS

Although older persons with depression were excluded, in studies on pain and cognition one should control for the presence of depressive symptoms in older persons with and without dementia.