Tuesday

C-REACTIVE PROTEIN

Just a Biomarker of Inflammation or a Pathophysiological Player in Myocardial Function and Morphology?
bY: Rainer Schulz, Gerd Heusch

In response to inflammatory stress, C-reactive protein (CRP) is predominantly secreted from the liver and adipose tissue(s), and an independent relationship exists between different markers of overweight/obesity and elevated high sensitive (hs) CRP levels

Higher hsCRP levels predict incident myocardial infarction (MI), stroke, peripheral arterial disease, sudden cardiac death, and all-cause mortality in healthy individuals with no history of cardiovascular disease.1,2 hsCRP at admission predicts in-hospital outcome, and hsCRP at discharge predicts 6-month event rate and 30-day mortality (Global Utilization of Strategies To Open occluded arteries [GUSTO] IV) in patients with an acute coronary syndrome. Indeed, adding hsCRP levels to the Global Registry in Acute Coronary Events (GRACE) acute coronary syndrome risk model improves the prediction of 30-day mortality. In patients with non-ST-elevated MI, an increased hsCRP level predicts the death rate even at 20-month follow-up but does not predict stent-related complications.

The question of whether CRP, apart from serving as a biomarker, acts as a causal factor in vascular/coronary artery disease has been addressed in animal models, in which CRP was injected or genetically …

Monday

Cross-Sectional Associations of Albuminuria and C-Reactive Protein With Functional Disability in Older Adults With Diabetes

OBJECTIVE To examine the relationship between albuminuria, inflammation, and disability in older adults with diabetes.

RESEARCH DESIGN AND METHODS Data were from 1,729 adults (≥60 years) with diabetes in the National Health and Nutrition Examination Survey, 1999–2008. Disability in activities of daily living (ADL), instrumental activities of daily living (IADL), leisure and social activities (LSA), general physical activities (GPA), and lower-extremity mobility (LEM) was obtained from self-reports. Urinary albumin-to-creatinine ratio (UACR) (mg/g) was categorized into normal (UACR <30 mg/g), microalbuminuria (UACR 30–300 mg/g), and macroalbuminuria (UACR >300 mg/g). C-reactive protein (CRP) levels were quantified by latex-enhanced nephelometry.

RESULTS In the full-adjusted model, microalbuminuria was associated with disability in ADL, LSA, and LEM with corresponding odds ratios (ORs) (95% CIs) of 1.51 (1.16–1.98), 1.62 (1.23–2.14), and 1.34 (1.03–1.74), respectively, compared with participants without albuminuria. Macroalbuminuria was associated with disability in ADL, IADL, and LEM with corresponding ORs (95% CIs) of 1.94 (1.24–3.03), 1.93 (1.23–3.02), and 2.20 (1.38–3.49), respectively, compared with participants without albuminuria. Elevated CRP (>0.3 mg/dL) was associated with increased odds of disability in ADL and LEM, with corresponding ORs (95% CIs) of 1.28 (1.00–1.62) and 1.68 (1.34–2.11), respectively. Subjects with both albuminuria and elevated CRP had higher odds of disability than individuals with no albuminuria and normal CRP.

CONCLUSIONS Albuminuria and inflammation were independent correlates for disability among older adults with diabetes. There was an interaction of albuminuria and elevated CRP on disability, suggesting that the presence of subclinical inflammation may amplify the effect of albuminuria on disability in older adults living with diabetes.

Hsu-Ko Kuo, MD, MPH1, Soham Al Snih, MD, PHD1,2, Yong-Fang Kuo, PHD1,2,3 and Mukaila A. Raji, MD1,2

Wednesday

Changes in C-reactive protein from low-fat diet and/or physical activity in men and women with and without metabolic syndrome

Change in high-sensitivity C-reactive protein (CRP) from low-fat diet (diet) and physical activity (PA) interventions is relatively unknown for adults with metabolic syndrome. The objective of the study was to assess CRP change (ΔCRP) with diet and/or PA in men and women with and without metabolic syndrome. Men (n = 149) and postmenopausal women (n = 125) with elevated low-density lipoprotein cholesterol and low high-density lipoprotein cholesterol were recruited into a 1-year randomized controlled trial.

Treatment groups were as follows: control, diet (reduced total fat, saturated fat, and cholesterol intake), PA (45-60 minutes at 60%-85% maximum heart rate), or diet + PA. Weight loss was not an intervention focus. Metabolic syndrome was defined using the American Heart Association/National Heart, Lung, and Blood Institute criteria.

Stored plasma samples were analyzed for CRP. Change in CRP was compared between treatments, within sex and metabolic syndrome status, using analysis of covariance, including covariates for baseline CRP and body fat change. For women with metabolic syndrome (n = 39), ΔCRP was greater in diet vs control (-1.2 ± 0.4, P = .009), diet + PA vs control (-1.3 ± 0.4, P = .006), and diet + PA vs PA (-1.1 ± 0.4, P = .02). Women with metabolic syndrome receiving the diet component (diet or diet + PA) had greater ΔCRP compared with those who did not (control or PA) (P = .001).

Change in CRP was not significantly different between intervention groups in men overall, women overall, men with (n = 47) or without metabolic syndrome (n = 102), or women without metabolic syndrome (n = 86). Low-fat diet may be the most effective treatment for reducing CRP in women with metabolic syndrome.

Author(s)
CAMHI Sarah M. (1) ; STEFANICK Marcia L. (2) ; RIDKER Paul M. (3) ; ROHM YOUNG Deborah (4) ;

Monday

Increased Consumption of Fatty and Lean Fish Reduces Serum C-Reactive Protein Concentrations but Not Inflammation Markers

Journal of Nutrition, doi:10.3945/jn.109.113472
Vol. 140, No. 2, 371-376, February 2010

Fish consumption is associated with a reduced colorectal cancer risk. A possible mechanism by which fish consumption could decrease colorectal cancer risk is by reducing inflammation. However, thus far, intervention studies investigating both systemic and local gut inflammation markers are lacking. Our objective in this study was to investigate the effects of fatty and lean fish consumption on inflammation markers in serum, feces, and gut. In an intervention study, participants were randomly allocated to receive dietary advice (DA) plus either 300 g of fatty fish (salmon) or 300 g of lean fish (cod) per week for 6 mo, or only DA.

Serum C-reactive protein (CRP) concentrations were measured pre- and postintervention (n = 161). In a subgroup (n = 52), we explored the effects of the fish intervention on fecal calprotectin and a wide range of cytokines and chemokines in fecal water and in colonic biopsies. Serum CRP concentrations were lower in the salmon (–0.5 mg/L; 95% CI –0.9, –0.2) and cod (–0.4 mg/L; 95% CI –0.7, 0.0) groups compared with the DA group. None of the inflammation markers in fecal water and colonic biopsies differed between the DA group and the groups that consumed extra fish.

In conclusion, increasing salmon or cod consumption for 6 mo resulted in lower concentrations of the systemic inflammation marker CRP. However, exploratory analysis of local markers of inflammation in the colon or feces did not reveal an effect of fish consumption.


Gerda K. Pot5, Anouk Geelen5, Gosia Majsak-Newman6, Linda J. Harvey6, Fokko M. Nagengast7, Ben J. M. Witteman8, Paul C. van de Meeberg9, Andrew R. Hart10,11, Gertjan Schaafsma1, Elizabeth K. Lund2, Ger T. Rijkers12,13 and Ellen Kampman5,*

5 Division of Human Nutrition, Wageningen University, Wageningen 6703 HD, The Netherlands; 6 Nutrition and Gastrointestinal Health, Institute of Food Research, Norwich NR4 7UA, UK; 7 UMC St Radboud, Nijmegen 6525 GA, The Netherlands; 8 Gelderse Vallei Hospital, Ede 6716 RP, The Netherlands; 9 Slingeland Hospital, Doetinchem 7000 AD, The Netherlands; 10 Norfolk and Norwich University Hospital NHS Trust, NR4 7UY, UK; 11 University of East Anglia, Norwich NR4 7TJ, UK; 12 Department of Surgery, University Medical Center Utrecht, Utrecht 3508 GA, The Netherlands; 13 Laboratory of Medical Microbiology and Immunology, St. Antonius Hospital, Nieuwegein 3430 EM, The Netherlands

Tuesday

C-Reactive Protein Inhibits Insulin Activation of Endothelial Nitric Oxide Synthase via the Immunoreceptor Tyrosine-Based Inhibition Motif of FcRIIB a

Keiji Tanigaki, Chieko Mineo, Ivan S. Yuhanna, Ken L. Chambliss, Michael J. Quon, Ezio Bonvini, Philip W. Shaul

Insulin promotes the cardiovascular protective functions of the endothelium including NO production by endothelial NO synthase (eNOS), which it stimulates via Akt kinase which phosphorylates eNOS Ser1179. C-reactive protein (CRP) is an acute-phase reactant that is positively correlated with cardiovascular disease risk in patients with type 2 diabetes.

We previously showed that CRP inhibits eNOS activation by insulin by blunting Ser1179 phosphorylation. We now elucidate the underlying molecular mechanisms. We first show in mice that CRP inhibits insulin-induced eNOS phosphorylation, indicating that these processes are operative in vivo. In endothelial cells we find that CRP attenuates insulin-induced Akt phosphorylation, and CRP antagonism of eNOS is negated by expression of constitutively active Akt; the inhibitory effect of CRP on Akt is also observed in vivo.

A requirement for the IgG receptor FcRIIB was demonstrated in vitro using blocking antibody, and reconstitution experiments with wild-type and mutant FcRIIB in NIH3T3IR cells revealed that these processes require the ITIM (immunoreceptor tyrosine-based inhibition motif) of the receptor. Furthermore, we find that endothelium express SHIP-1 (Src homology 2 domain–containing inositol 5'-phosphatase 1), that CRP induces SHIP-1 stimulatory phosphorylation in endothelium in culture and in vivo, and that SHIP-1 knockdown by small interfering RNA prevents CRP antagonism of insulin-induced eNOS activation.

Thus, CRP inhibits eNOS stimulation by insulin via FcRIIB and its ITIM, SHIP-1 activation, and resulting blunted activation of Akt. These findings provide mechanistic linkage among CRP, impaired insulin signaling in endothelium, and greater cardiovascular disease risk in type 2 diabetes.

C-reactive protein elicits white blood cell activation in humans.

C-Reactive Protein Study:
OBJECTIVE: Consistent epidemiologic evidence suggests that acute infections increase the risk for acute cardiovascular events. We tested in humans whether activation of peripheral leukocytes in reaction to the administration of recombinant human C-reactive protein (rhCRP) may provide a mechanism for infectious diseases to promote atherosclerotic disease.

METHODS AND RESULTS: By using quantitative real-time polymerase chain reaction analysis, whole-blood expression profiles were analyzed for 95 inflammatory markers before and after infusion of 1.25 mg/kg rhCRP in 5 male volunteers. Relevant transcript levels were measured at baseline and 4 and 8 hours after rhCRP-infusion. CRP caused significant up-regulation of matrix metalloproteinase (MMP)-9, monocyte chemoattractant protein (MCP)-1, plasminogen activator urokinase, macrophage inflammatory protein 1 alpha, and nuclear factor of kappa B inhibitor mRNAs in peripheral leukocytes. mRNA up-regulation of MMP-9 and MCP-1 was 17- and 11-fold, respectively. The corresponding increase in plasma protein levels of MMP-9 (78+/-32 ng/mL to 109+/-41 ng/mL; P=.014) and MCP-1 (312+/-92 pg/mL to 2590+/-898 pg/mL; P=.007) closely mirrored mRNA findings. Also, in whole-blood culture stimulation assays, CRP induced proinflammatory changes. Notably, heat inactivation abolished the capacity of CRP to evoke these proinflammatory changes, excluding a role for contaminants within the purified CRP preparation.

CONCLUSION: CRP elicits activation of peripheral leukocytes with ensuing secretion of plaque-destabilizing mediators. These findings are consistent with the hypothesis that infectious diseases trigger manifestations of atherosclerosis, in which CRP elevation might contribute to the onset of cardiovascular events.

Bisoendial RJ, Birjmohun RS, Akdim F, van 't Veer C, Spek CA, Hartman D, de Groot ER, Bankaitis-Davis DM, Kastelein JJ, Stroes ES.
Department of Vascular Medicine, Academic Medical Center, Amsterdam, The Netherlands

Thursday

Are there Bi-directional Associations between Depressive Symptoms and C-Reactive Protein in Mid-life Women?

OBJECTIVE: To test whether depressive symptoms are related to subsequent C-reactive protein (CRP) levels and/or whether CRP levels are related to subsequent depressive symptoms in mid-life women. METHODS: Women enrolled in the Study of Women's Health Across the Nation (SWAN) were followed for seven years and had measures of CES-Depression scores and CRP seven times during the follow-up period. Women were pre- or early peri-menopausal at study entry and were of Caucasian, African American, Hispanic, Japanese, or Chinese race/ethnicity. Analyses were restricted to initially healthy women.

RESULTS: Longitudinal mixed linear regression models adjusting for age, race, site, time between exams, and outcome variable at year X showed that higher CES-D scores predicted higher subsequent CRP levels and vice versa over a 7-year period. Full multivariate models adjusting for body mass index, physical activity, medications, health conditions, and other covariates showed that higher CRP levels at year X predicted higher CES-D scores at year X+1, p = 0.03. Higher depressive symptoms predicted higher subsequent CRP levels at marginally significant levels, p=0.10.

CONCLUSIONS: Higher CRP levels led to higher subsequent depressive symptoms, albeit the effect was small. The study demonstrates the importance of considering bi-directional relationships for depression and other psychosocial factors and risk for heart disease.

Matthews KA, Schott LL, Bromberger JT, Cyranowski JM, Everson-Rose SA, Sowers M.
University of Pittsburgh, 3811 O'Hara Street, Pittsburgh, PA 15213