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Objectives: Inflammation is considered as a major effector of arterial damage brought about by salt excess in animal models. In a randomized, single masked, cross-over study in 32 uncomplicated essential hypertensive patients, we assessed the effect of a short-term low-salt diet on biomarkers of innate immunity [procalcitonin (PCT), interleukin-6, C-reactive protein, and tumor necrosis factor-α (TNF-α)], adiponectin (ADPN, an anti-inflammatory cytokine), and leptin., Methods: Patients were randomized to either a 10-20 mmol sodium diet and sodium tablets (180 mEq/day) to achieve a 200 mmol intake per day or the same diet and identical placebo tablets, each for 2 weeks. At the end of each of these periods, all patients underwent a 24-h urine collection, a fasting blood sampling, and a 24 h ambulatory blood pressure monitoring., Results: In parallel with expected increase in plasma renin activity and aldosterone (P<0.001), both PCT (+33%) and TNF-α (9%) rose at low salt intake (P≤0.007) while ADPN underwent an opposite change (- 17%, P<0.001). In a linear regression analysis for repeated measurements, PCT was significantly and inversely related to urinary salt (weighted r=-0.27, P=0.03). Changes in inflammation biomarkers did not differ in salt-sensitive (n=7) and salt-resistant (n=25) patients., Conclusion: In essential hypertensive patients, a very low salt diet generates a pro-inflammatory phenotype characterized by an increase in PCT and TNF-α and an opposite effect on an anti-inflammatory cytokine like ADPN.

Background and Methods: The endogenous inhibitor of nitric oxide synthase (NOs) asymmetrical dimethyl-arginine (ADMA) has been implicated as a possible modulator of inducible NOs during acute inflammation. We examined the evolution in the plasma concentration of ADMA measured at the clinical outset of acute inflammation and after its resolution in a series of 17 patients with acute bacterial infections., Results: During the acute phase of inflammation/infection, patients displayed very high levels of C-reactive protein (CRP), interleukin-6 (IL-6), procalcitonin and nitrotyrosine. Simultaneous plasma ADMA concentration was similar to that in healthy subjects while symmetric dimethyl-arginine (SDMA) levels were substantially increased and directly related with creatinine. When infection resolved, ADMA rose from 0.62 +/- 0.23 to 0.80 +/- 0.18 micromol/l (+29%, P = 0.01) while SDMA remained unmodified. ADMA changes were independent on concomitant risk factor changes and inversely related with baseline systolic and diastolic pressure. Changes in the ADMA/SDMA ratio were compatible with the hypothesis that inflammatory cytokines activate ADMA degradation., Conclusions: Resolution of acute inflammation is characterized by an increase in the plasma concentration of ADMA. The results imply that ADMA suppression may actually serve to stimulate NO synthesis or that in this situation plasma ADMA levels may not reflect the inhibitory potential of this methylarginine at the cellular level.

Background: Low T3 is a frequent alteration in patients with ESRD. This derangement has been recently linked to inflammation in haemodialysis patients. Whether this association holds true in peritoneal dialysis patients has not been studied., Methods: We investigated the relationship between low-grade inflammation [IL-6, C-reactive protein (CRP) and serum albumin levels] and free tri-iodothyronine (fT3) in a cohort of 41 CAPD patients (mean age, 66 years; M, 26; F, 15) without heart failure and inter-current illnesses., Results: CAPD patients had lower fT3 levels (2.7 +/- 0.8 pg/ml) than healthy subjects (3.7 +/- 1.0 pg/ml, P < 0.001) of similar age. Free T3 levels were directly related to those of serum albumin (r = 0.52, P = 0.001) and inversely to IL-6 (r = -0.30, P = 0.05) and CRP (r = -0.54, P < 0.001). Age (r = -0.61, P < 0.001), haemoglobin levels (r = 0.32, P = 0.05) and diastolic blood pressure (r = 0.50, P = 0.001) were also related to fT3. In multiple regression models adjusting for all variables related to fT3, CRP and albumin were retained as independent correlates of fT3. During the follow-up (2.8 +/- 1.7 years) 27 patients died. Plasma fT3 levels were lower in patients who died (2.5 +/- 0.8 pg/ml) compared with survivors (3.3 +/- 0.5 pg/ml P = 0.001). In Cox analyses, fT3 was a significant predictor of mortality independent of the main traditional as well as non-traditional risk factors., Conclusions: The relationship between fT3, CRP and serum albumin suggests that inflammation-malnutrition might be involved in the low T3 syndrome in CAPD patients. Thyroid dysfunction might be implicated in the pathogenic pathway which links micro-inflammation to survival in PD patients.

From an evolutionary perspective, Darwinian selection has favored insulin-resistant individuals, ie, those with a trait ensuring brain functioning in situations of extreme fuel deprivation. The ability to mount a powerful inflammatory response to infection was another survival advantage in our ancestors, and we now have solid evidence showing that these 2 traits, insulin resistance and inflammation (as measured by serum C-reactive protein [CRP]), are associated in modern human beings. In an analysis of 192 nondiabetic hemodialysis patients, leptin and adiponectin were related in an opposite fashion with insulin sensitivity in end-stage renal disease (ESRD) and interacted in determining insulin resistance in these patients. The risk of insulin resistance was about 6 times higher in ESRD patients with an unfavorable combination of the 2 adipokines (high leptin and low adiponectin) than in those with a favorable combination (low leptin and high adiponectin). Low adiponectin but not high leptin predicted incident cardiovascular events in this cohort. Neither leptin nor adiponectin were associated with CRP in a cross-sectional analysis, but they were linked in an opposite fashion to CRP in a longitudinal study in 21 patients with acute inflammation secondary to infection. High sympathetic activity predicts adverse cardiovascular outcomes in ESRD. Of note, we found that the risk for cardiovascular events is more than 3 times higher in patients with high sympathetic activity and low adiponectin than in those with high adiponectin and low sympathetic activity. The adipocyte hormones leptin and adiponectin are associated in an opposite fashion to insulin sensitivity and inflammation in ESRD patients. Relatively lower plasma adiponectin levels are associated with a higher rate of incident cardiovascular events. Finally, low adiponectin and high norepinephrine seem to be interacting factors in the dismal cardiovascular outcomes with ESRD.

• In patients with kidney failure undergoing dialysis, neutrophils are dysfunctionally activated. • Plasma levels of MPO and resistin correlate with overall and cardiovascular mortality risk in kidney failure patients undergoing dialysis. • Inflammatory markers can mediate the high risk of death and CV events and can prove useful tools in risk stratification of patients undergoing dialysis. In patients with kidney failure (KF) undergoing dialysis, neutrophils are dysfunctionally activated. Such chronic activation does not correspond to increased protection against infections and is thought to cause direct vascular damage accounting for the higher incidence of cardiovascular (CV) events. We hypothesized that circulating levels of neutrophil degranulation products (i.e. myeloperoxidase (MPO) and resistin) can predict overall and CV-specific mortality in dialysis patients. MPO and resistin levels were assessed in plasma samples from n = 1182 dialysis patients who were followed-up for median 2.9 years (IQR: 1.7–4.2). Patients were 65 ± 14 (SD) years old and 36 % women. Median value of MPO and resistin were 78 ng/mL (IQR: 54 - 123) and 72 ng/mL (IQR: 46 - 110), respectively. MPO and resistin levels correlated with biomarkers of organ damage, nutritional status and inflammation. Both MPO and resistin levels predicted all-cause mortality even after adjustment for traditional risk factors and inflammation, nutritional and KF-related indexes (MPO, HR for 1 ln unit increase : 1.26, 95 %CI 1.11 – 1.42, P < 0.001; Resistin, HR for 1 ln unit increase : 1.25, 95 %CI 1.09 – 1.44, P = 0.001). Similarly, their predictive ability held true also for CV death (MPO, HR for 1 ln unit increase : 1.19, 95 %CI 1.01 – 1.41, P = 0.04; Resistin, HR for 1 ln unit increase : 1.29, 95 %CI 1.07 – 1.56, P = 0.007). Plasma levels of MPO and resistin correlate with prospective overall and CV-specific mortality risk in KF patients undergoing dialysis and might be useful prognostic tools. Mediators of inflammation may be potential target to improve survival of those patients. [ABSTRACT FROM AUTHOR]

Background High FGF23 and low α-Klotho levels associate with systemic inflammation and reduced nitric oxide (NO) bioavailability, but the dynamics of this relationship in patients with CKD has not been investigated. Methods We sequentially measured serum intact FGF23 and carboxyl-terminal (iFGF23, cFGF23), the iFGF23/cFGF23 ratio, αKlotho, biomarkers of inflammation (hs-CRP, IL-6 and TNF-α) and sepsis (procalcitonin), nitrotyrosine (reflecting NO synthesis and oxidative stress), serum iron and ferritin and CKD-MBD biomarkers, PTH, 25(OH)VD, 1,25(OH)2VD at peak of intercurrent sepsis and after complete resolution in a series of 17 patients with CKD. Results At peak infection, biomarkers of inflammation/sepsis, ferritin and nitrotyrosine were all very high (all P < 0·01) and declined towards the normal range thereafter ( P < 0·01). iFGF23 was 191 ± 10 pg/ml (geometric mean, SD) and doubled to 371 ± 8 pg/ml ( P = 0·003) after the resolution of infection, while cFGF23 did not change (246 ± 5 pg/mL vs. 248 ± 5 pg/mL, P = 0·50). As a consequence, the iFGF23/cFGF23 ratio, an indicator of the proteolytic cleavage of the FGF23 molecule, was 0·78 ± 3·87 at peak infection and increased to 1·49 ± 3·00 after resolution of infection ( P < 0·001). In contrast, serum α-Klotho levels were upregulated at peak infection (peak infection: 526 ± 4 pg/ml, postinfection: 447 ± 4 pg/ml, P = 0·001). The eGFR, PTH and vitamin D did not change significantly throughout. Conclusions Acute inflammation/sepsis suppresses the active form of FGF23 and activates α-Klotho, the latter effect being likely attributable to enhance proteolysis of FGF23 molecule. iFGF23 downregulation and α-Klotho upregulation during acute sepsis may participate into the counter-regulatory response to severe inflammation in CKD patients with sepsis. [ABSTRACT FROM AUTHOR]