Environmental hypoxia influences the development of inflammatory bowel diseases. Adaptive responses to hypoxia are mediated through hypoxia-inducible factors, which are tightly regulated by oxygen- and iron-dependent hydroxylases. Regulation of uptake, storage and export of iron is mediated by signals reflecting oxygen and intracellular iron levels in enterocytes. Conversely, iron modulates responses to hypoxia. We sought to elucidate the effects of iron levels on hypoxia-associated responses in the intestinal epithelium. Human subjects were exposed to hypoxia, and colonic biopsies and serum samples were collected. The human intestinal epithelial cells HT-29, Caco-2 and T84 were subjected to hypoxia in the presence of iron or the iron chelator deferoxamine. Changes in inflammatory gene expression and signalling were assessed by qPCR and western blot. Chromatin immunoprecipitation was performed using antibodies against NF-κB and primers for promoter binding regions of TNF and IL-1β Human subjects presented reduced levels of ferritin and iron in the intestinal epithelium following hypoxia. Hypoxia reduced iron deprivation-associated TNF and IL-1β expression in HT-29 cells through the induction of autophagy. Contrarily, hypoxia triggered TNF and IL-1β expression, and NF-κB activation in Caco-2 and T84 cells. In Caco-2 cells, iron blocked early and late-stage autophagy while reducing hypoxia-associated TNF and IL-1β expression, and the binding of NF-κB to the promoter of TNF and IL-1β. Hypoxia-induced autophagy reduces inflammation in HT-29 cells. In Caco-2 cells, iron uptake is essential to prevent hypoxia-induced inflammatory processes. Iron mobilisation plays a crucial role in the maintenance of homeostasis in the hypoxic intestinal epithelium.

Intestinal fibrosis and stenosis are common complications of Crohn's disease [CD], frequently requiring surgery. Anti-inflammatory strategies can only partially prevent fibrosis; hence, anti-fibrotic therapies remain an unmet clinical need. Oxysterols are oxidised cholesterol derivatives with important roles in various biological processes. The enzyme cholesterol 25-hydroxylase [CH25H] converts cholesterol to 25-hydroxycholesterol [25-HC], which modulates immune responses and oxidative stress. In human intestinal samples from CD patients, we found a strong correlation of CH25H mRNA expression with the expression of fibrosis markers. We demonstrate reduced intestinal fibrosis in mice deficient for the CH25H enzyme, using the sodium dextran sulphate [DSS]-induced chronic colitis model. Additionally, using a heterotopic transplantation model of intestinal fibrosis, we demonstrate reduced collagen deposition and lower concentrations of hydroxyproline in CH25H knockouts. In the heterotopic transplant model, CH25H was expressed in fibroblasts. Taken together, our findings indicate an involvement of oxysterol synthesis in the pathogenesis of intestinal fibrosis.

In inflammatory bowel disease (IBD), inflammation is sustained by an exaggerated response of lymphocytes. This results from enhanced expression of anti-apoptotic B cell lymphoma (BCL-2) and BCL-XL associated with a diminished turnover. Azathioprine (AZA) directly targets BCL-2 family-mediated apoptosis. We investigated whether the BCL-2 family expression pattern could be used to predict treatment response to AZA and determined whether BCL-2 inhibitor A-1211212 effectively diminishes lymphocytes and ameliorates inflammation in a model of colitis. BCL-2 family expression pattern was determined by next-generation sequencing (NGS). BCL-2 inhibitor was administered orally to Il10-/- mice. Haematological analyses were performed with an ADVIA 2120 and changes in immune cells were investigated using quantitative polymerase chain reaction (qPCR) and fluorescence activated cell sorter (FACS). We determined similar expression levels of BCL-2 family members in patients with remission and patients refractory to treatment, showing that BCL-2 family expression can not predict AZA treatment response. Expression was not correlated with the modified Truelove and Witts activity index (MTWAI). BCL-2 inhibitor initiated cell death in T cells from patients refractory to AZA and reduced lymphocyte count in Il10-/- mice. FACS revealed diminished CD8+ T cells upon BCL-2 inhibitor in Il10-/- mice without influencing platelets. Tnf, Il1β, IfnƔ and Mcp-1 were decreased upon BCL-2 inhibitor. A-1211212 positively altered the colonic mucosa and ameliorated inflammation in mice. Pro-apoptotic BCL-2 inhibitor A-1211212 diminishes lymphocytes and ameliorates colitis in Il10-/- mice without inducing thrombocytopenia. BCL-2 inhibition could be a new therapy option for patients refractory to AZA.

Intestinal fibrosis is thought to be a consequence of excessive tissue repair, and constitutes a common problem in patients with Crohn’s disease (CD). While fibrosis seems to require inflammation as a prerequisite it is unclear whether the severity or persistence of inflammation influences the degree of fibrosis. Our aim was to investigate the role of sustained inflammation in fibrogenesis. For the initiation of fibrosis in vivo the models of Il10 −/− spontaneous colitis, dextran sodium sulfate (DSS)-induced chronic colitis and heterotopic transplantation were used. In Il10 −/− mice, we determined a positive correlation between expression of pro-inflammatory factors ( Il1β , Tnf , Ifnγ , Mcp1 and Il6 ). We also found a positive correlation between the expression of pro-fibrotic factors ( Col3a1 Col1a1 , Tgfβ and αSma ). In contrast, no significant correlation was determined between the expression of pro-inflammatory Tnf and pro-fibrotic αSma , Col1a1 , Col3a1 , collagen layer thickness and the hydroxyproline (HYP) content. Results from the DSS-induced chronic colitis model confirmed this finding. In the transplantation model for intestinal fibrosis a pronounced increase in Mcp1 , inos and Il6 in Il10 −/− as compared to WT grafts was observed, indicating more severe inflammation in Il10 −/− grafts. However, the increase of collagen over time was virtually identical in both Il10 −/− and WT grafts. Severity of inflammation during onset of fibrogenesis did not correlate with collagen deposition. Although inflammation might be a pre-requisite for the initiation of fibrosis our data suggest that it has a minor impact on the progression of fibrosis. Our results suggest that development of fibrosis and inflammation may be disconnected. This may be important for explaining the inefficacy of anti-inflammatory treatments agents in most cases of fibrotic inflammatory bowel diseases (IBD).

Integrins are receptors for extracellular matrix proteins and are involved in many critical cellular processes such as adhesion, migration, proliferation, differentiation and cell death. The β6-integrin subunit is merely detectable in normal epithelial tissues, whereas it is highly induced in epithelial cells during embryogenesis, wound repair as well as during tumorigenesis of many epithelial tumours such as colorectal cancer (CRC). In CRC, elevated β6-integrin levels are associated with reduced survival. Treatment of human CRC cell lines with immunoliposomes carrying siRNAs against β6-integrin reduced their migratory and invasive potential, induced apoptosis and reduced tumour growth of these cells. Since the exclusive expression of β6-integrin in epithelial tumours makes it an excellent drug target, we studied the efficacy of the αvβ6 inhibitor EMD527040 on tumour growth in mice with DSS/AOM induced colon tumours. Colitis-associated colon tumours were induced in C57BL/6 mice by repetitive administration of 1.5% DSS in drinking water and intraperitoneal AOM (10 mg/kg) injections. Mice without endoscopically detectable tumours after the DSS/AOM treatment were excluded from further study. The remaining mice were randomised to the different treatment groups according to their tumour load to obtain comparable groups at the beginning of the further treatment. Mice were then treated with vehicle, 20 mg/kg/day or 40 mg/kg/day EMD527040 for 24 days. Colonoscopy was performed to detect tumour development during the treatment course and to evaluate tumour load over time. Overall, treatment with EMD527040 was safe and we did not detect severe side effects of the tumour therapy. Mice that received vehicle or the low dose of EMD527040 showed either disease progression or no change in tumour load. No decrease in the number of colon tumours was observed in those two groups. However, in the group treated with the high dose of EMD527040 (40 mg/kg/day), only one mouse had disease progression and in two mice, which started treatment with a high tumour load, no progression or regression was observable. Of note however, in the remaining three mice which started with a moderate to low tumour load, a complete loss of tumours was observed upon high dose αvβ6 inhibitor treatment for 24 days. In early stage colitis-associated CRC (small tumours), treatment with αvβ6 inhibitor showed a strong anti-tumorigenic effect. Therefore, αvβ6 inhibition might be a potent strategy for treatment of CRC. However, the exact molecular mechanisms conferring this anti-tumorigenic effect, and whether other treatment schedules or doses could improve the effect in subjects with a high tumour load remains to be elucidated.

Dysregulation of the immune response to microbiota is associated with inflammatory bowel disease (IBD), which can trigger intestinal fibrosis. MyD88 is a key component of microbiota signalling but its influence on intestinal fibrosis has not been clarified. Small bowel resections from donor-mice were transplanted subcutaneously into the neck of recipients C57BL/6 B6-MyD88tm1 Aki (MyD88 −/− ) and C57BL/6-Tg(UBC-green fluorescence protein (GFP))30Scha/J (GFP-Tg). Grafts were explanted up to 21 days after transplantation. Collagen layer thickness was determined using Sirius Red stained slides. In the mouse model of fibrosis collagen deposition and transforming growth factor-beta 1 (TGF-β1) expression was equal in MyD88 +/+ and MyD88 −/− , indicating that MyD88 was not essential for fibrogenesis. Matrix metalloproteinase ( Mmp )9 expression was significantly decreased in grafts transplanted into MyD88 −/− recipients compared to MyD88 +/+ recipients (0.2 ± 0.1 vs. 153.0 ± 23.1, respectively, p < 0.05), similarly recruitment of neutrophils was significantly reduced (16.3 ± 4.5 vs. 25.4 ± 3.1, respectively, p < 0.05). Development of intestinal fibrosis appears to be independent of MyD88 signalling indicating a minor role of bacterial wall compounds in the process which is in contrast to published concepts and theories. Development of fibrosis appears to be uncoupled from acute inflammation.

To dissect the genetic architecture of blood pressure and assess effects on target organ damage, we analyzed 128,272 SNPs from targeted and genome-wide arrays in 201,529 individuals of European ancestry, and genotypes from an additional 140,886 individuals were used for validation. We identified 66 blood pressure-associated loci, of which 17 were new; 15 harbored multiple distinct association signals. The 66 index SNPs were enriched for cis-regulatory elements, particularly in vascular endothelial cells, consistent with a primary role in blood pressure control through modulation of vascular tone across multiple tissues. The 66 index SNPs combined in a risk score showed comparable effects in 64,421 individuals of non-European descent. The 66-SNP blood pressure risk score was significantly associated with target organ damage in multiple tissues but with minor effects in the kidney. Our findings expand current knowledge of blood pressure-related pathways and highlight tissues beyond the classical renal system in blood pressure regulation.

OBJECTIVE:Cardiac changes of hypertensive pregnancy include left ventricular hypertrophy (LVH) and diastolic dysfunction. These are thought to regress postpartum. We hypothesised that women with a history of hypertensive pregnancy would have altered LV geometry and function when compared with women with only normotensive pregnancies.METHODS:In this cohort study, we analysed echocardiograms of 2637 women who participated in the Family Blood Pressure Program. We compared LV mass and function in women with hypertensive pregnancies with those with normotensive pregnancies.RESULTS:Women were evaluated at a mean age of 56 years: 427 (16%) had at least one hypertensive pregnancy; 2210 (84%) had normotensive pregnancies. Compared with women with normotensive pregnancies, women with hypertensive pregnancy had a greater risk of LVH (OR: 1.42; 95% CI 1.01 to 1.99, p=0.05), after adjusting for age, race, research network of the Family Blood Pressure Program, education, parity, BMI, hypertension and diabetes. When duration of hypertension was taken into account, this relationship was no longer significant (OR: 1.19; CI 0.08 to 1.78, p=0.38). Women with hypertensive pregnancies also had greater left atrial size and lower mitral E/A ratio after adjusting for demographic variables. The prevalence of systolic dysfunction was similar between the groups.CONCLUSIONS:A history of hypertensive pregnancy is associated with LVH after adjusting for risk factors; this might be explained by longer duration of hypertension. This finding supports current guidelines recommending surveillance of women following a hypertensive pregnancy, and sets the stage for longitudinal echocardiographic studies to further elucidate progression of LV geometry and function after pregnancy.CLINICAL TRIAL REGISTRATIONS:GENOA- NCT00005269; HyperGEN- NCT00005267; Sapphire- NCT00005270; GenNet- NCT00005268.

BackgroundEndogenous cardiotonic steroids (CTS) bind to the renal Na+/K+-ATPase and promote natriuresis, but may also be pro-oxidant and pro-fibrotic. In 'salt-sensitive' animal models of heart failure with preserved ejection fraction (HFPEF), changes in the CTS marinobufagenin (MBG) during high sodium intake closely parallel the transition from hypertensive heart disease to HFPEF, and antibodies to MBG reduce blood pressure and cardiovascular damage. In human HFPEF, urinary MBG levels and their response to changes in dietary sodium intake have not previously been reported.MethodsWe administered the sodium (Na)-restricted DASH diet (SRD; 50 mmol Na/2100 kcal) for 21 days to 12 patients with treated hypertension, stable diuretic use, and compensated HFPEF. Pre- and post-intervention 24-hour urinary collection was used to estimate dietary Na intake, which was corroborated through dietary surveys. Urinary aldosterone (Aldo), F2-isoprostanes (F2-iso, a measure of systemic oxidative stress), and MBG levels (via DELFIA immunoassay) were measured at both time points. Paired t-testing was used to compare pre-post values and linear regression to investigate relationships between MBG, F2-iso, Aldo, and Na excretion, with these variables indexed for urinary creatinine (Cr) to facilitate analysis.ResultsFollowing SRD, 24-hour urinary Na and urinary Na:Cr decreased (3,353±1,593 to 1,478±933 mg/24h, p<.001; 59±79 to 30±20 mg Na/mg Cr, p=.01; Figure A) , urinary Aldo:Cr increased (6.7±2.6 to 14.2±7.3 pg/mg, p=.009), yet F2-iso:Cr decreased (6.0±2.5 to 4.3±1.4 pg/mg, p=.04). The MBG:Cr did not significantly differ between baseline and SRD (2.8±0.7 to 2.8±1.3 pM/mg, p=.91), but showed substantial variability between patients (Figure B). The change (Δ) in MBG:Cr between baseline and post-SRD was closely related to ΔNa:Cr (Figure C). By linear regression ΔMBG:Cr was associated with ΔNa:Cr (β=23.8, p<.001) and ΔF2-iso:Cr (β=1.1, p=.06) independent of ΔAldo:Cr.Conclusions BackgroundEndogenous cardiotonic steroids (CTS) bind to the renal Na+/K+-ATPase and promote natriuresis, but may also be pro-oxidant and pro-fibrotic. In 'salt-sensitive' animal models of heart failure with preserved ejection fraction (HFPEF), changes in the CTS marinobufagenin (MBG) during high sodium intake closely parallel the transition from hypertensive heart disease to HFPEF, and antibodies to MBG reduce blood pressure and cardiovascular damage. In human HFPEF, urinary MBG levels and their response to changes in dietary sodium intake have not previously been reported. Endogenous cardiotonic steroids (CTS) bind to the renal Na+/K+-ATPase and promote natriuresis, but may also be pro-oxidant and pro-fibrotic. In 'salt-sensitive' animal models of heart failure with preserved ejection fraction (HFPEF), changes in the CTS marinobufagenin (MBG) during high sodium intake closely parallel the transition from hypertensive heart disease to HFPEF, and antibodies to MBG reduce blood pressure and cardiovascular damage. In human HFPEF, urinary MBG levels and their response to changes in dietary sodium intake have not previously been reported. MethodsWe administered the sodium (Na)-restricted DASH diet (SRD; 50 mmol Na/2100 kcal) for 21 days to 12 patients with treated hypertension, stable diuretic use, and compensated HFPEF. Pre- and post-intervention 24-hour urinary collection was used to estimate dietary Na intake, which was corroborated through dietary surveys. Urinary aldosterone (Aldo), F2-isoprostanes (F2-iso, a measure of systemic oxidative stress), and MBG levels (via DELFIA immunoassay) were measured at both time points. Paired t-testing was used to compare pre-post values and linear regression to investigate relationships between MBG, F2-iso, Aldo, and Na excretion, with these variables indexed for urinary creatinine (Cr) to facilitate analysis. We administered the sodium (Na)-restricted DASH diet (SRD; 50 mmol Na/2100 kcal) for 21 days to 12 patients with treated hypertension, stable diuretic use, and compensated HFPEF. Pre- and post-intervention 24-hour urinary collection was used to estimate dietary Na intake, which was corroborated through dietary surveys. Urinary aldosterone (Aldo), F2-isoprostanes (F2-iso, a measure of systemic oxidative stress), and MBG levels (via DELFIA immunoassay) were measured at both time points. Paired t-testing was used to compare pre-post values and linear regression to investigate relationships between MBG, F2-iso, Aldo, and Na excretion, with these variables indexed for urinary creatinine (Cr) to facilitate analysis. ResultsFollowing SRD, 24-hour urinary Na and urinary Na:Cr decreased (3,353±1,593 to 1,478±933 mg/24h, p<.001; 59±79 to 30±20 mg Na/mg Cr, p=.01; Figure A) , urinary Aldo:Cr increased (6.7±2.6 to 14.2±7.3 pg/mg, p=.009), yet F2-iso:Cr decreased (6.0±2.5 to 4.3±1.4 pg/mg, p=.04). The MBG:Cr did not significantly differ between baseline and SRD (2.8±0.7 to 2.8±1.3 pM/mg, p=.91), but showed substantial variability between patients (Figure B). The change (Δ) in MBG:Cr between baseline and post-SRD was closely related to ΔNa:Cr (Figure C). By linear regression ΔMBG:Cr was associated with ΔNa:Cr (β=23.8, p<.001) and ΔF2-iso:Cr (β=1.1, p=.06) independent of ΔAldo:Cr. Following SRD, 24-hour urinary Na and urinary Na:Cr decreased (3,353±1,593 to 1,478±933 mg/24h, p<.001; 59±79 to 30±20 mg Na/mg Cr, p=.01; Figure A) , urinary Aldo:Cr increased (6.7±2.6 to 14.2±7.3 pg/mg, p=.009), yet F2-iso:Cr decreased (6.0±2.5 to 4.3±1.4 pg/mg, p=.04). The MBG:Cr did not significantly differ between baseline and SRD (2.8±0.7 to 2.8±1.3 pM/mg, p=.91), but showed substantial variability between patients (Figure B). The change (Δ) in MBG:Cr between baseline and post-SRD was closely related to ΔNa:Cr (Figure C). By linear regression ΔMBG:Cr was associated with ΔNa:Cr (β=23.8, p<.001) and ΔF2-iso:Cr (β=1.1, p=.06) independent of ΔAldo:Cr. Conclusions

We read with great interest the review "Dietary Sodium Restriction: Take It With a Grain of Salt," by DiNicolantonio et al.1DiNicolantonio J.J. Niazi A.K. Sadaf R. O'Keefe J.H. Lucan S.C. Lavie C.J. Dietary sodium restriction: take it with a grain of salt.Am J Med. 2013; 126: 951-955Abstract Full Text Full Text PDF PubMed Scopus (29) Google Scholar The authors point out the paucity of data linking dietary sodium restriction to reductions in cardiovascular events and provide an excellent and broad-based overview of many important studies. However, we want to raise several issues for comment.The authors conclude that "there is sound evidence that a low sodium diet leads to a worse cardiovascular prognosis in patients with systolic congestive heart failure…." This statement is based on several studies performed by a single Italian research group, in which large loop diuretic doses (100-500 mg/d furosemide equivalent) were continued for months in outpatient participants regardless of clinical status. For reference, the mean furosemide equivalent dose at hospital discharge in large North American and European studies is 50 to 80 mg/d,2Nunez J. Nunez E. Minana G. et al.Differential mortality association of loop diuretic dosage according to blood urea nitrogen and carbohydrate antigen 125 following a hospitalization for acute heart failure.Eur J Heart Fail. 2012; 14: 974-984Crossref PubMed Scopus (21) Google Scholar, 3Abdel-Qadir H.M. Tu J.V. Yun L. Austin P.C. Newton G.E. Lee D.S. Diuretic dose and long-term outcomes in elderly patients with heart failure after hospitalization.Am Heart J. 2010; 160: 264-271Abstract Full Text Full Text PDF PubMed Scopus (74) Google Scholar and discharge furosemide doses of ≥240 mg/d predict higher mortality even in the very ill heart failure population in the Evaluation Study of Congestive Heart Failure and Pulmonary Artery Catheterization Effectiveness study.4O'Connor C.M. Hasselblad V. Mehta R.H. et al.Triage after hospitalization with advanced heart failure: the ESCAPE (Evaluation Study of Congestive Heart Failure and Pulmonary Artery Catheterization Effectiveness) risk model and discharge score.J Am Coll Cardiol. 2010; 55: 872-878Abstract Full Text Full Text PDF PubMed Scopus (176) Google Scholar In this setting, it seems difficult to conclude that low-sodium diets "caused increased mortality and heart failure hospitalizations" rather than the known neurohormonal and renal effects of high-dose diuretics in the setting of volume depletion.Abundant data from animal models and humans suggest that at least some persons would benefit greatly from dietary sodium restriction. DiNicolantonio et al1DiNicolantonio J.J. Niazi A.K. Sadaf R. O'Keefe J.H. Lucan S.C. Lavie C.J. Dietary sodium restriction: take it with a grain of salt.Am J Med. 2013; 126: 951-955Abstract Full Text Full Text PDF PubMed Scopus (29) Google Scholar correctly characterize sodium consumption as physiologically regulated and challenging to modulate. However, it is not impossible to do so in populations, as evidenced by successful policy-driven sodium intake reductions in Finland and the United Kingdom.5Polonia J. Martins L. A comprehensive review on salt and health and current experience of worldwide salt reduction programmes.J Hum Hypertens. 2009; 23: 771-772Crossref PubMed Scopus (17) Google Scholar We strongly believe that additional research, particularly in special populations such as those with heart failure, is needed before dismissing such efforts as potentially "counterproductive…and risky." We read with great interest the review "Dietary Sodium Restriction: Take It With a Grain of Salt," by DiNicolantonio et al.1DiNicolantonio J.J. Niazi A.K. Sadaf R. O'Keefe J.H. Lucan S.C. Lavie C.J. Dietary sodium restriction: take it with a grain of salt.Am J Med. 2013; 126: 951-955Abstract Full Text Full Text PDF PubMed Scopus (29) Google Scholar The authors point out the paucity of data linking dietary sodium restriction to reductions in cardiovascular events and provide an excellent and broad-based overview of many important studies. However, we want to raise several issues for comment. The authors conclude that "there is sound evidence that a low sodium diet leads to a worse cardiovascular prognosis in patients with systolic congestive heart failure…." This statement is based on several studies performed by a single Italian research group, in which large loop diuretic doses (100-500 mg/d furosemide equivalent) were continued for months in outpatient participants regardless of clinical status. For reference, the mean furosemide equivalent dose at hospital discharge in large North American and European studies is 50 to 80 mg/d,2Nunez J. Nunez E. Minana G. et al.Differential mortality association of loop diuretic dosage according to blood urea nitrogen and carbohydrate antigen 125 following a hospitalization for acute heart failure.Eur J Heart Fail. 2012; 14: 974-984Crossref PubMed Scopus (21) Google Scholar, 3Abdel-Qadir H.M. Tu J.V. Yun L. Austin P.C. Newton G.E. Lee D.S. Diuretic dose and long-term outcomes in elderly patients with heart failure after hospitalization.Am Heart J. 2010; 160: 264-271Abstract Full Text Full Text PDF PubMed Scopus (74) Google Scholar and discharge furosemide doses of ≥240 mg/d predict higher mortality even in the very ill heart failure population in the Evaluation Study of Congestive Heart Failure and Pulmonary Artery Catheterization Effectiveness study.4O'Connor C.M. Hasselblad V. Mehta R.H. et al.Triage after hospitalization with advanced heart failure: the ESCAPE (Evaluation Study of Congestive Heart Failure and Pulmonary Artery Catheterization Effectiveness) risk model and discharge score.J Am Coll Cardiol. 2010; 55: 872-878Abstract Full Text Full Text PDF PubMed Scopus (176) Google Scholar In this setting, it seems difficult to conclude that low-sodium diets "caused increased mortality and heart failure hospitalizations" rather than the known neurohormonal and renal effects of high-dose diuretics in the setting of volume depletion. Abundant data from animal models and humans suggest that at least some persons would benefit greatly from dietary sodium restriction. DiNicolantonio et al1DiNicolantonio J.J. Niazi A.K. Sadaf R. O'Keefe J.H. Lucan S.C. Lavie C.J. Dietary sodium restriction: take it with a grain of salt.Am J Med. 2013; 126: 951-955Abstract Full Text Full Text PDF PubMed Scopus (29) Google Scholar correctly characterize sodium consumption as physiologically regulated and challenging to modulate. However, it is not impossible to do so in populations, as evidenced by successful policy-driven sodium intake reductions in Finland and the United Kingdom.5Polonia J. Martins L. A comprehensive review on salt and health and current experience of worldwide salt reduction programmes.J Hum Hypertens. 2009; 23: 771-772Crossref PubMed Scopus (17) Google Scholar We strongly believe that additional research, particularly in special populations such as those with heart failure, is needed before dismissing such efforts as potentially "counterproductive…and risky." Dietary Sodium Restriction: Take It with a Grain of SaltThe American Journal of MedicineVol. 126Issue 11PreviewThe American Heart Association recently strongly recommended a dietary sodium intake of <1500 mg/d for all Americans to achieve "Ideal Cardiovascular Health" by 2020. However, low sodium diets have not been shown to reduce cardiovascular events in normotensive individuals or in individuals with pre-hypertension or hypertension. Moreover, there is evidence that a low sodium diet may lead to a worse cardiovascular prognosis in patients with cardiometabolic risk and established cardiovascular disease. Full-Text PDF The ReplyThe American Journal of MedicineVol. 127Issue 6PreviewWe thank Hummel and Weder for their response1 to our article2 pertaining to the potential harms of restricting dietary sodium. The 2 doctors suggest there is a lack of sound evidence that low-sodium diets increase hospitalizations and mortality versus normal-sodium diets because the trials cited in our review used unusual diuretic dosing. Specifically, Hummel and Weder are concerned about high doses of furosemide not commonly used in the United States or Europe. However, in the largest randomized trial we cite (n = 1771), investigators gave furosemide at a dose of 50 mg twice daily (ie, 100 mg/d) to approximately two thirds of all enrolled patients. Full-Text PDF

BACKGROUND:Candidate gene and twin studies suggest that interactions between body mass index (BMI) and genes contribute to the variability of blood pressure (BP). To determine whether there is evidence for gene-BMI interactions, we investigated the modulation of BP heritability by BMI using 4,153 blacks, 1,538 Asians, 4,013 whites, and 2,199 Hispanic Americans from the Family Blood Pressure Program.METHODS:To capture the BP heritability dependence on BMI, we employed a generalized variance components model incorporating linear and Gaussian interactions between BMI and the genetic component. Within each race and network subgroup, we used the Akaike information criterion and likelihood ratio test to select the appropriate interaction function for each BP trait (systolic BP (SBP), diastolic BP (DBP), mean arterial pressure (MAP), and pulse pressure (PP)) and determine interaction significance, respectively.RESULTS:BP heritabilities were significantly modified by BMI in the GenNet and SAPPHIRe Networks, which contained the youngest and least-obese participants, respectively. GenNet Whites had unimodal SBP, MAP, and PP heritabilities that peaked between BMI values of 33 and 37kg/m(2). The SBP and MAP heritabilities in GenNet Hispanic Americans, as well as the PP heritability in GenNet blacks, were increasing functions of BMI. The DBP and SBP heritabilities in the SAPPHIRe Chinese and Japanese, respectively, were decreasing functions of BMI.CONCLUSIONS:BP heritability differed by BMI in the youngest and least-obese networks, although the shape of this dependence differed by race. Use of nonlinear gene-BMI interactions may enhance BP gene discovery efforts in individuals of European ancestry.

Hypertension guidelines recommend following published standardized protocols to obtain accurate blood pressure (BP) readings in clinical practice. However, the various measurement techniques among clinical trials that provide the basis for evidence-based management have not been evaluated or compared with guideline recommendations. We reviewed published information regarding BP measurement in clinical trials (n = 64) from 1990-2014 by searching PubMed and Google Scholar databases. Every trial failed to provide published information regarding at least one of the 10 methodological aspects we evaluated. Details regarding the health-care provider(s) performing measurement(s), temporal-relation to last medication dosage, number of readings, resting time before (and between recordings), and the device(s) used varied among the trials and often differed from clinical recommendations. Most studies did evaluate ≥2 BP readings in a seated position, presumably from the upper arm (although explicit acknowledgment of this latter detail was rare). When indicated, "trough" BP levels were most commonly obtained (15 of 16 trials), whereas the usage of automated devices increased over time. Numerous aspects of BP measurement varied considerably across trials and often from most recent guideline recommendations. The lack of uniform methodologies in outcome studies that form the foundation of evidence-based guidelines may have significant clinical implications.

Although variants in many genes have previously been shown to be associated with blood pressure (BP) levels, the molecular mechanism underlying these associations are mostly unknown. We identified a multi-allelic T-rich sequence (TRS) in the 3'UTR of ATP1B1 that varies in length and sequence composition (T22-27 and T12GT 3GT6). The 3'UTR of ATP1B1 contains 2 functional polyadenylation signals and the TRS is downstream of the proximal polyadenylation site (A2). Therefore, we hypothesized that alleles of this TRS might influence ATP1B1 expression by regulating alternative polyadenylation. In vitro, the T12GT 3GT6 allele increases polyadenylation at the A2 polyadenylation site as compared to the T23 allele. Consistent with our hypothesis, the relative abundance of the A2-polyadenylated ATP1B1 mRNA was higher in human kidneys with at least one copy of the T12GT 3GT6 allele than in those lacking this allele. The T12GT 3GT6 allele is also associated with higher systolic BP (beta = 3.3 mmHg, p = 0.014) and diastolic BP (beta = 2.4 mmHg, p = 0.003) in a European-American population. Therefore, we have identified a novel multi-allelic TRS in the 3'UTR of ATP1B1 that is associated with higher BP and may mediate its effect by regulating the polyadenylation of the ATP1B1 mRNA.

Background— Heart failure with preserved ejection fraction (HFPEF) involves failure of cardiovascular reserve in multiple domains. In HFPEF animal models, dietary sodium restriction improves ventricular and vascular stiffness and function. We hypothesized that the sodium-restricted dietary approaches to stop hypertension diet (DASH/SRD) would improve left ventricular diastolic function, arterial elastance, and ventricular–arterial coupling in hypertensive HFPEF. Methods and Results— Thirteen patients with treated hypertension and compensated HFPEF consumed the DASH/SRD (target sodium, 50 mmol/2100 kcal) for 21 days. We measured baseline and post-DASH/SRD brachial and central blood pressure (via radial arterial tonometry) and cardiovascular function with echocardiographic measures (all previously invasively validated). Diastolic function was quantified via the parametrized diastolic filling formalism that yields relaxation/viscoelastic ( c ) and passive/stiffness ( k ) constants through the analysis of Doppler mitral inflow velocity (E-wave) contours. Effective arterial elastance ( E a ) end-systolic elastance ( E es ) and ventricular–arterial coupling (defined as the ratio E es : E a ) were determined using previously published techniques. Wilcoxon matched-pairs signed-rank tests were used for pre–post comparisons. The DASH/SRD reduced clinic and 24-hour brachial systolic pressure (155±35 to 138±30 and 130±16 to 123±18 mm Hg; both P =0.02), and central end-systolic pressure trended lower (116±18 to 111±16 mm Hg; P =0.12). In conjunction, diastolic function improved ( c =24.3±5.3 to 22.7±8.1 g/s; P =0.03; k =252±115 to 170±37 g/s 2 ; P =0.03), E a decreased (2.0±0.4 to 1.7±0.4 mm Hg/mL; P =0.007), and ventricular–arterial coupling improved ( E es : E a =1.5±0.3 to 1.7±0.4; P =0.04). Conclusions— In patients with hypertensive HFPEF, the sodium-restricted DASH diet was associated with favorable changes in ventricular diastolic function, arterial elastance, and ventricular–arterial coupling. Clinical Trial Registration— URL: http://www.clinicaltrials.gov . Unique identifier: NCT00939640.

Genome-wide linkage and association studies of hypertension (HTN) aim to uncover loci that are involved in blood pressure (BP) regulation and the pathophysiology of HTN. However, even when such loci are successfully identified, the mechanism by which the implicated genes increase HTN susceptibility is not well understood. ATP1B1, which encodes the beta subunit of Na+, K+ ATPase, a co-transporter involved in multiple BP-regulating physiological processes, is located within a well-established BP linkage peak. Although a single nucleotide polymorphism (rs12079745) in the 3’UTR of ATP1B1 has previously been shown to be associated with BP levels, the molecular mechanism underlying this association is unknown. We identified a multi-allelic T-rich element (TRE) in the 3’UTR of ATP1B1 that varies in length and sequence composition (T22-27 and T12GT3GT6). The 3’UTR of ATP1B1 contains 2 functional polyadenylation signals and the TRE is downstream of the proximal site (A2). Because U-rich elements (UREs) in 3’UTRs are known to play a role in the cleavage and polyadenylation of mRNA, and ATP1B1 transcripts with shorter 3’UTRs are translationally more efficient, we hypothesized that alleles of this TRE might influence ATP1B1 expression by regulating alternative polyadenylation. Consistent with our hypothesis, the A2-polyadenylated mRNA isoform was more abundant in human kidneys with at least one copy of T12GT3GT6 than in those homozygous for the T22-27 alleles. Functionally, in vitro, we demonstrated that the T12GT3GT6 allele has greater luciferase activity than the T22 allele and that the T12GT3GT6 allele shows increased polyadenylation at the A2 site than the T22 allele. In addition, the TRE element is associated with systolic BP in European Americans of the GenNet network of the NHLBI Family Blood Pressure Program, with the T12GT3GT6 allele being associated with higher BP (effect size = 2.4 mmHg SBP, P = 0.003). Sharing strong linkage disequilibrium with rs12079745, this TRE is likely the functional site underlying the original association. In summary, we have identified a novel multi-allelic TRE in the 3’UTR of ATP1B1. Alleles at this site are associated with HTN and may mediate their effect on BP by regulating polyadenylation of the ATP1B1 mRNA.

Recent studies suggest that oxidative stress and vascular dysfunction contribute to heart failure with preserved ejection fraction (HFPEF). In salt-sensitive HFPEF animal models, diets low in sodium and high in potassium, calcium, magnesium, and antioxidants attenuate oxidative stress and cardiovascular damage. We hypothesized that the sodium-restricted Dietary Approaches to Stop Hypertension diet (DASH/SRD) would have similar effects in human hypertensive HFPEF. Thirteen patients with treated hypertension and compensated HFPEF consumed the DASH/SRD for 21 days (all food/most beverages provided). The DASH/SRD reduced clinic systolic (155–138 mm Hg; P=0.02) and diastolic blood pressure (79–72 mm Hg; P=0.04), 24-hour ambulatory systolic (130–123 mm Hg; P=0.02) and diastolic blood pressure (67–62 mm Hg; P=0.02), and carotid-femoral pulse wave velocity (12.4–11.0 m/s; P=0.03). Urinary F2-isoprostanes decreased by 31% (209–144 pmol/mmol Cr; P=0.02) despite increased urinary aldosterone excretion. The reduction in urinary F2-isoprostanes closely correlated with the reduction in urinary sodium excretion on the DASH/SRD. In this cohort of HFPEF patients with treated hypertension, the DASH/SRD reduced systemic blood pressure, arterial stiffness, and oxidative stress. These findings are characteristic of salt-sensitive hypertension, a phenotype present in many HFPEF animal models and suggest shared pathophysiological mechanisms linking these 2 conditions. Further dietary modification studies could provide insights into the development and progression of hypertensive HFPEF.