Cumulative stress and autonomic dysregulation in a community sample.

Whether cumulative stress, including both chronic stress and adverse life events, is associated with decreased heart rate variability (HRV), a non-invasive measure of autonomic status which predicts poor cardiovascular outcomes, is unknown. Healthy community dwelling volunteers (N = 157, mean age 29 years) participated in the Cumulative Stress/Adversity Interview (CAI), a 140-item event interview measuring cumulative adversity including major life events, life trauma, recent life events and chronic stressors, and underwent 24-h ambulatory ECG monitoring. HRV was analyzed in the frequency domain and standard deviation of NN intervals (SDNN) calculated. Initial simple regression analyses revealed that total cumulative stress score, chronic stressors and cumulative adverse life events (CALE) were all inversely associated with ultra low-frequency (ULF), very low-frequency (VLF) and low-frequency (LF) power and SDNN (all p < 0.05). In hierarchical regression analyses, total cumulative stress and chronic stress each was significantly associated with SDNN and ULF even after the highly significant contributions of age and sex, with no other covariates accounting for additional appreciable variance. For VLF and LF, both total cumulative stress and chronic stress significantly contributed to the variance alone but were not longer significant after adjusting for race and health behaviors. In summary, total cumulative stress, and its components of adverse life events and chronic stress were associated with decreased cardiac autonomic function as measured by HRV. Findings suggest one potential mechanism by which stress may exert adverse effects on mortality in healthy individuals. Primary preventive strategies including stress management may prove beneficial.

Stress-related alcohol consumption in heavy drinkers correlates with expression of miR-10a, miR-21, and components of the TAR-RNA-binding protein-associated complex.

BACKGROUND: Alterations in stress-related gene expression may play a role in stress-related drinking and the risk of alcohol dependence. METHODS: Microarrays were used to measure changes in gene expression in peripheral blood in nonsmoking, social drinking subjects exposed to 3 types of personalized imagery: neutral, stressful (but not alcohol related), and alcohol-related cues. Gene expression was measured at baseline, immediately after, and 1 hour after stimulus presentation. Subjects were allowed to drink up to 750 cc of beer in a "taste test" following stimulus presentation in each imagery condition, and the amount of beer consumed was recorded. Gene-expression levels were compared in 2 groups of nonsmoking subjects (n = 11/group): heavy drinkers (HD; defined as regular alcohol use over the past year of at least 8 standard drinks per week for women and at least 15 standard drinks per week for men), and moderate drinkers (MD; defined as up to 7 standard drinks per week for women and 14 standard drinks per week for men). Expression of microRNA-10a (miR-10a) and microRNA-21 (miR-21) was assessed by quantitative real-time polymerase chain reaction. RESULTS: After correction for multiple testing (false discovery rate < 0.05), 79 genes were identified that changed by >1.3-fold in the HD group, but not the MD group, following exposure to stress. No changes were observed for any of these genes in either group following exposure to neutral or alcohol-related imagery. Pathway analysis suggested that many of these genes, form part of the transactivation responsive (TAR)-RNA-binding protein (TRBP)-associated complex and are positively regulated by miR-10a and miR-21. Expression of both miR-10a and miR-21 was up-regulated following psychological stress in HD, but not MD subjects; however, the differences between groups were not statistically significant. Expression levels of both microRNAs was correlated (miR-10a, R(2)  = 0.59, miR-21 R(2)  = 0.57) with amount drunk in HD, but not MD subjects. CONCLUSIONS: Expression of miR-10a, miR-21, and several of their target genes is regulated by acute psychological stress and is correlated with stress-induced drinking in a laboratory setting. Alterations in miRNA expression may be one mechanism linking psychological stress with changes in gene expression and increased alcohol intake in binge/HD.

Error processing and gender-shared and -specific neural predictors of relapse in cocaine dependence.

Deficits in cognitive control are implicated in cocaine dependence. Previously, combining functional magnetic resonance imaging and a stop signal task, we demonstrated altered cognitive control in cocaine-dependent individuals. However, the clinical implications of these cross-sectional findings and, in particular, whether the changes were associated with relapse to drug use, were not clear. In a prospective study, we recruited 97 treatment-seeking individuals with cocaine dependence to perform the stop signal task during functional magnetic resonance imaging and participate in follow-up assessments for 3 months, during which time cocaine use was evaluated with timeline follow back and ascertained by urine toxicology tests. Functional magnetic resonance imaging data were analysed using general linear models as implemented in Statistical Parametric Mapping 8, with the contrast 'stop error greater than stop success trials' to index error processing. Using voxelwise analysis with logistic and Cox regressions, we identified brain activations of error processing that predict relapse and time to relapse. In females, decreased error-related activations of the thalamus and dorsal anterior cingulate cortex predicted relapse and an earlier time to relapse. In males, decreased error-related activations of the dorsal anterior cingulate cortex and left insula predicted relapse and an earlier time to relapse. These regional activations were validated with data resampling and predicted relapse with an average area under the curve of 0.849 in receiver operating characteristic analyses. These findings provide direct evidence linking deficits in cognitive control to clinical outcome in a moderate-sized cohort of cocaine-dependent individuals. These results may provide a useful basis for future studies to examine how psychosocial factors interact with cognitive control to determine drug use and to evaluate the efficacy of pharmacological or behavioural treatment in remediating deficits of cognitive control in cocaine addicts.

Adjudication of etiology of acute kidney injury: experience from the TRIBE-AKI multi-center study.

BACKGROUND: Adjudication of patient outcomes is a common practice in medical research and clinical trials. However minimal data exists on the adjudication process in the setting of Acute Kidney Injury (AKI) as well as the ability to judge different etiologies (e.g. Acute Tubular Necrosis (ATN), Pre-renal Azotemia (PRA)). METHODS: We enrolled 475 consecutive patients undergoing cardiac surgery at four sites of the Translational Research Investigating Biomarker Endpoints in AKI (TRIBE-AKI) study. Three expert nephrologists performed independent chart review, utilizing clinical variables and retrospective case report forms with pre intra and post-operative data, and then adjudicated all cases of AKI (n = 67). AKI was defined as a > 50% increase in serum creatinine for baseline (RIFLE Risk). We examined the patterns of AKI diagnoses made by the adjudication panel as well as association of these diagnoses with pre and postoperative kidney injury biomarkers. RESULTS: There was poor agreement across the panel of reviewers with their adjudicated diagnoses being independent of each other (Fleiss' Kappa = 0.046). Based on the agreement of the two out of three reviewers, ATN was the adjudicated diagnosis in 41 cases (61%) while PRA occurred in 13 (19%). Neither serum creatinine or any other biomarker of AKI (urine or serum), was associated with an adjudicated diagnosis of ATN within the first 24 post-operative hours. CONCLUSION: The etiology of AKI after cardiac surgery is probably multi-factorial and pure forms of AKI etiologies, such as ATN and PRA may not exist. Biomarkers did not appear to correlate with the adjudicated etiology of AKI; however the lack of agreement among the adjudicators impacted these results. TRIAL REGISTRATION: Clinicaltrials.gov: NCT00774137.

Urinary cystatin C and acute kidney injury after cardiac surgery.

BACKGROUND: Acute kidney injury (AKI) is common after cardiac surgery and is associated with adverse patient outcomes. Urinary cystatin C (CysC) level is a biomarker of proximal tubule function and may increase earlier in AKI than serum creatinine level. STUDY DESIGN: Prospective cohort study. SETTINGS & PARTICIPANTS: The TRIBE AKI (Translational Research Investigating Biomarker Endpoints in AKI) Consortium prospectively enrolled 1,203 adults and 299 children and adolescents at 8 institutions in 2007-2009. INDEX TEST: Urinary CysC (in milligrams per liter) within the first 12 hours after surgery. OUTCOME: Serum creatinine-based AKI was defined as AKI Network stage 1 (mild AKI) and doubling of serum creatinine from the preoperative value or need for dialysis during hospitalization (severe AKI). OTHER MEASUREMENTS: Analyses were adjusted for characteristics used clinically for AKI risk stratification, including age, sex, race, estimated glomerular filtration rate, diabetes, hypertension, heart failure, nonelective surgery, cardiac catheterization within 72 hours, type of surgery, myocardial infarction, and cardiopulmonary bypass time longer than 120 minutes. RESULTS: Urinary CysC level measured in the early postoperative period (0-6 and 6-12 hours postoperatively) correlated with both mild and severe AKI in adults and children. However, after analyses were adjusted for other factors, the effect was attenuated for both forms of AKI in both cohorts. LIMITATIONS: Limited numbers of patients with severe AKI and in-hospital dialysis treatment. CONCLUSIONS: Urinary CysC values are not associated significantly with the development of AKI after cardiac surgery in adults and children.

Preoperative angiotensin-converting enzyme inhibitors and angiotensin receptor blocker use and acute kidney injury in patients undergoing cardiac surgery.

BACKGROUND: Using either an angiotensin-converting enzyme inhibitor (ACEi) or an angiotensin receptor blocker (ARB) the morning of surgery may lead to 'functional' postoperative acute kidney injury (AKI), measured by an abrupt increase in serum creatinine. Whether the same is true for 'structural' AKI, measured with new urinary biomarkers, is unknown. METHODS: The TRIBE-AKI study was a prospective cohort study of 1594 adults undergoing cardiac surgery at six hospitals between July 2007 and December 2010. We classified the degree of exposure to ACEi/ARB into three categories: 'none' (no exposure prior to surgery), 'held' (on chronic ACEi/ARB but held on the morning of surgery) or 'continued' (on chronic ACEi/ARB and taken the morning of surgery). The co-primary outcomes were 'functional' AKI based upon changes in pre- to postoperative serum creatinine, and 'structural AKI', based upon peak postoperative levels of four urinary biomarkers of kidney injury. RESULTS: Across the three levels (none, held and continued) of ACEi/ARB exposure there was a graded increase in functional AKI, as defined by AKI stage 1 or worse; (31, 34 and 42%, P for trend 0.03) and by percentage change in serum creatinine from pre- to postoperative (25, 26 and 30%, P for trend 0.03). In contrast, there were no differences in structural AKI across the strata of ACEi/ARB exposure, as assessed by four structural AKI biomarkers (neutrophil gelatinase-associated lipocalin, kidney injury molecule-1, interleukin-18 or liver-fatty acid-binding protein). CONCLUSIONS: Preoperative ACEi/ARB usage was associated with functional but not structural acute kidney injury. As AKI from ACEi/ARB in this setting is unclear, interventional studies testing different strategies of perioperative ACEi/ARB use are warranted.

Altered expression of cytokine signaling pathway genes in peripheral blood cells of alcohol dependent subjects: preliminary findings.

BACKGROUND: Preclinical and clinical studies have implicated changes in cytokine and innate immune gene-expression in both the development of and end-organ damage resulting from alcohol dependence. However, these changes have not been systematically assessed on the basis of alcohol consumption in human subjects. METHODS: Illumina Sentrix Beadchip (Human-6v2) microarrays were used to measure levels of gene-expression in peripheral blood in 3 groups of subjects: those with alcohol dependence (AD, n = 12), heavy drinkers (HD; defined as regular alcohol use over the past year of at least 8 standard drinks/wk for women and at least 15 standard drinks/wk for men, n = 13), and moderate drinkers (MD; defined as up to 7 standard drinks/wk for women and 14 standard drinks/wk for men, n = 17). RESULTS: Four hundred and thirty-six genes were differentially expressed among the 3 groups of subjects (false discovery rate corrected p-value < 0.05). Two hundred and ninety-one genes differed between AD and MD subjects, 240 differed between AD and HD subjects, but only 6 differed between HD and MD subjects. Pathway analysis using DAVID and GeneGO Metacore(®) software showed that the most affected pathways were those related to T-cell receptor and Janus kinase-Signal transducer and activator of transcription (JAK-Stat) signaling. CONCLUSIONS: These results suggest the transition from heavy alcohol use to dependence is accompanied by changes in the expression of genes involved in regulation of the innate immune response. Such changes may underlie some of the previously described changes in immune function associated with chronic alcohol abuse. Early detection of these changes may allow individuals at high risk for dependence to be identified.

Behavioral arousal in response to stress and drug cue in alcohol and cocaine addicted individuals versus healthy controls.

UNLABELLED: Negative emotional arousal in response to stress and drug cues is known to play a role in the development and continuation of substance use disorders. However, studies have not examined behavioral indicators of such arousal. OBJECTIVE: The current study examined behavioral and bodily arousal in response to stress and drug cue in individuals with alcohol dependence and cocaine dependence as compared to healthy controls using a new scale. METHODS: Fifty-two alcohol dependent (AD group), 45 cocaine dependent (COC group), and 68 healthy controls (HC group) were exposed to individually developed stressful, drug-cue, and neutral-relaxing imagery. Behavioral and bodily responses were assessed with a new scale, the Behavioral Arousal Scale (BAS). RESULTS: The BAS showed acceptable inter-rater reliability and internal consistency and correlated with subjective negative emotion and craving. BAS scores were higher in stress than neutral conditions for all three groups. COC participants showed higher BAS response to stress than AD or HC participants. COC and AD participants showed greater BAS response to drug cue than HC participants. CONCLUSION: Behavioral arousal is a domain in which stress and drug related arousal is expressed and assessment of this domain could provide unique information about vulnerability to craving and relapse in addicted populations.

Sex-specific dissociations in autonomic and HPA responses to stress and cues in alcohol-dependent patients with cocaine abuse.

AIMS: Chronic alcohol and drug dependence leads to neuroadaptations in hypothalamic-pituitary-adrenal (HPA) and sympathetic adrenal medullary (SAM) stress systems, which impact response sensitivity to stress and alcohol cue and facilitates risk of relapse. To date, gender variations in these systems have not been fully assessed in abstinent alcohol-dependent individuals who also met criteria for cocaine abuse. METHODS: Forty-two (21 M/21 F) early abstinent treatment-seeking substance-abusing (SA) men and women and 42 (21 M/21 F) healthy control (HC) volunteers were exposed to three 5-min guided imagery conditions (stress, alcohol/drug cue, neutral relaxing), presented randomly, one per day across three consecutive days. Alcohol craving and anxiety ratings were obtained as well as measures of heart rate (HR), blood pressure, plasma ACTH, cortisol, norepinephrine (NE) and epinephrine (EPI). RESULTS: SA males showed increased ACTH and EPI basal tone compared with HC males and SA females. However, they demonstrated no increase in ACTH and cortisol levels following stress and alcohol cue imagery exposure compared to the neutral condition. SA females demonstrated a typically increased stress response in both measures. In addition, SA males showed no increase in cardiovascular response to either stress or cue, and no increase in catecholamine response to cue compared with their response to neutral imagery. Again, this dampening was not observed in HC males who produced significantly higher levels of cue-related HR and EPI, and significantly higher stress-related DBP. In contrast, SA females showed an enhanced ACTH and cortisol response to stress and cue compared with neutral imagery and this was not observed in the HC females. They also demonstrated a reduced increase in NE and EPI compared with both SA males and HC females as well as reduced HR compared with HC females. CONCLUSIONS: While SA males showed a generalized suppression of HPA, SAM system and cardiovascular markers following both stress and cue, SA women demonstrated a selective sympatho-adrenal suppression to stress only and an enhanced HPA response to both stress and cue. These gender variations are discussed in terms of their potential impact on relapse vulnerability and treatment outcome.

Enhanced sensitivity to stress and drug/alcohol craving in abstinent cocaine-dependent individuals compared to social drinkers.

Chronic exposure to cocaine is associated with neuroadaptions in stress and reward circuits that may increase susceptibility to relapse. We examined whether there are alterations in stress response and craving in abstinent cocaine-dependent individuals compared with a demographically matched group of non-addicted socially drinking community controls. Forty treatment-engaged abstinent cocaine patients (17F/23M) and 40 controls (19F/21M) were exposed to a brief 5 min guided imagery of individually calibrated stressful situations, personal drug/alcohol-related situation and a neutral-relaxing situation, one imagery per session, presented in random order. Craving, anxiety, emotion rating scales, and physiological measures were assessed. Cocaine patients reported significantly higher and more persistent stress- and cue-induced drug/alcohol craving, negative emotions, and physiological responses compared with social drinkers. In cocaine patients, stress- and cue-induced drug craving was accompanied by increased anger, fear, sadness, heart rate, and SBP. Controls reported minimal stress-induced craving and only increases in anxiety and SBP during stress exposure. Cue-induced alcohol craving was accompanied only by an increase in relaxed state. Females reported increased stress-induced anxiety and sadness compared with males, while males were emotionally and physiologically more reactive in the cue condition. These findings are the first to document functional alterations in stress- and reward-related affect and physiology in recently abstinent cocaine patients that is marked by an enhanced sensitivity to stress- and drug-related cue exposure. These data suggest that recovery from chronic cocaine abuse could be hampered by a hyper-responsive stress- and drug-craving state that increases cocaine relapse susceptibility.

Altered levels of sex and stress steroid hormones assessed daily over a 28-day cycle in early abstinent cocaine-dependent females.

RATIONALE: There is growing evidence of alterations in brain stress and reward circuits associated with cocaine dependence. Sex differences are also documented and sex steroid hormones have been linked to cocaine reinforcement. OBJECTIVES: The current study therefore assessed daily fluctuations in stress and sex hormones in cocaine-dependent females compared with healthy females. METHOD: Daily salivary samples of cortisol, progesterone, and estradiol were collected at waking across 28 days from 12 cocaine-dependent females receiving inpatient treatment and 10 healthy females. Participants also completed mood-rating scales each week corresponding to four phases of the menstrual cycle and cocaine craving was monitored in cocaine patients at each phase. RESULTS: Cocaine-dependent females in their first month of abstinence demonstrated significantly higher levels of both cortisol and progesterone across the menstrual cycle and significantly lower estradiol/progesterone (E2/P) ratios compared to healthy controls. They also showed significantly increased negative mood compared with controls, but no variation in cocaine craving across the menstrual cycle. CONCLUSIONS: Findings indicate altered stress and sex hormones suggestive of an overactive stress system during the first month of cocaine abstinence after chronic cocaine abuse. These increased levels of cortisol and progesterone could impact both abstinence-related symptoms such as negative mood and susceptibility to drug-seeking behavior in cocaine-dependent females.

Gender differences in response to emotional stress: an assessment across subjective, behavioral, and physiological domains and relations to alcohol craving.

BACKGROUND: Women and men are at risk for different types of stress-related disorders, with women at greater risk for depression and anxiety and men at greater risk for alcohol-use disorders. The present study examines gender differences in emotional and alcohol craving responses to stress that may relate to this gender divergence in disorders. METHOD: Healthy adult social drinkers (27 men, 27 women) were exposed to individually developed and calibrated stressful, alcohol-related, and neutral-relaxing imagery, 1 imagery per session, on separate days and in random order. Subjective emotions, behavioral/bodily responses, cardiovascular arousal [heart rate (HR), blood pressure (BP)], and self-reported alcohol craving were assessed. RESULTS: Women reported and displayed greater sadness and anxiety following stress than men and men had greater diastolic BP response than women. No gender differences in alcohol craving, systolic BP or HR were observed. Subjective, behavioral, and cardiovascular measures were correlated in both genders. However, for men, but not women, alcohol craving was associated with greater subjective emotion and behavioral arousal following stress and alcohol cues. CONCLUSIONS: These data suggest that men and women respond to stress differently, with women experiencing greater sadness and anxiety, while men show a greater integration of reward motivation (craving) and emotional stress systems. These findings have implications for the gender-related divergence in vulnerability for stress-related disorders, with women at greater risk for anxiety and depression than men, and men at greater risk for alcohol-use disorders than women.

Stress and drug-cue-induced craving in opioid-dependent individuals in naltrexone treatment.

BACKGROUND: Naltrexone is a nonaddictive medication that blocks the euphoric effects of opioids. However, naltrexone treatment is associated with high rates of noncompliance and opioid relapse, possibly because it does not reduce stress and protracted withdrawal symptoms during early recovery. Prior clinical and preclinical research has indicated that both stress and drug-cue-related arousal response is associated with craving and vulnerability to relapse in a range of drug-using populations. AIMS: To examine opioid craving and the subjective and cardiovascular response to stress and drug cues in naltrexone-treated opioid abusers. METHOD: Eleven men and three women engaged in naltrexone treatment for opioid dependence. They were exposed to personalized stress, drug-cue, and neutral-relaxing imagery in a single laboratory session. Subjective (craving, emotion) and cardiovascular (heart rate, systolic blood pressure, and diastolic blood pressure) measures were assessed. RESULTS: Stress and drug-cue-related imagery significantly increased opioid craving, anxiety, and negative emotions and significantly decreased positive emotions compared to neutral imagery. Selective emotional responses were greater in the stress condition than in the drug-cue condition. Only stress-related imagery was associated with an increased cardiovascular response. CONCLUSIONS: Naltrexone-treated opioid abusers demonstrate vulnerability to stress and drug-cue-induced craving and arousal responses that may contribute to the high rates of noncompliance and relapse among opioid-dependent individuals undergoing naltrexone treatment. Pharmacological and behavioral interventions that specifically target the negative affectivity that co-occurs with drug-cue and stress-induced craving could be of benefit in improving naltrexone treatment outcomes in opioid dependence.

Sex steroid hormones, stress response, and drug craving in cocaine-dependent women: implications for relapse susceptibility.

Cocaine dependence is associated with an enhanced sensitivity to stress and drug craving. Increases in stress-induced craving and hypothalamic-pituitary-adrenal reactivity are also predictive of cocaine relapse outcomes. More important, sex differences in these responses have also been reported. To further understand the basis of the sex differences, the authors examined the influence of sex steroid hormones on subjective and physiological stress responses and drug craving in cocaine-dependent women. Women who had low progesterone levels (n=5) were compared with those with high progesterone levels (n=5) and with those with moderate levels of estradiol and progesterone (n=9) in their responses during exposure to stress, cocaine cues, and neutral imagery conditions. The high progesterone group showed significantly lower stress-induced and drug cue-induced cocaine craving ( p<.05) and reduced drug cue-induced anxiety levels ( p<.08) and lower drug cue-induced systolic and diastolic blood pressure levels compared with the low progesterone group. These data suggest that there are significant effects of sex steroid hormones on stress and drug cue-induced cocaine craving, anxiety, and cardiovascular responses. In particular, high progesterone during the midluteal phase of the cycle was associated with decreased stress-induced and drug cue-induced craving and decreased cue-induced anxiety and blood pressure responses. These findings are consistent with previous preclinical and clinical studies of progesterone's effects on the behavioral responses to cocaine and warrant further research to examine the effects of progesterone on stress-induced cocaine craving, stress arousal, and cocaine relapse susceptibility in women.

Performance monitoring and stop signal inhibition in abstinent patients with cocaine dependence.

Impulsivity has been associated with drug abuse and relapse. As a measure of impulsivity, response inhibition in a stop signal task is impaired in substance abusers compared to healthy control subjects. However, cognitive processes besides response inhibition can affect performance in the stop signal task. Greater response readiness to the go signal increases stop signal reaction time (SSRT) and greater performance monitoring elicited by the stop signal decreases SSRT. Prolonged SSRT, therefore, may reflect differences in these other task-related cognitive processes rather than impaired response inhibition. Using a tracking stop-signal task, we compared 18 abstinent cocaine dependent patients with 41 age- and education-matched healthy controls. We computed SSRT for each individual subject on the basis of the horse race model. We also computed the fore-period (FP) effect to measure response readiness to the go signal and the post-signal slowing (PSS) effect to measure performance monitoring to the stop signal. Cocaine subjects showed increased SSRT and decreased PSS effect, compared to healthy controls. Covariance adjustment for the PSS effect eliminated the SSRT difference from healthy controls. These results suggest that diminished performance monitoring can be a critical cognitive mechanism underlying impaired response inhibition in cocaine dependent patients.

Serum brain natriuretic peptide and risk of acute kidney injury after cardiac operations in children.

BACKGROUND: Acute kidney injury (AKI) after pediatric cardiac operations is associated with poor outcomes and is difficult to predict. We conducted a prospective study to evaluate whether preoperative brain natriuretic peptide (BNP) levels predict postoperative AKI among children undergoing cardiac operations. METHODS: This was a three-center, prospective study (2007-2009) of 277 children undergoing cardiac operations (n = 121, aged <2 years) with available preoperative BNP values. Preoperative BNP was measured and categorized into tertiles. The performance of BNP was evaluated alone and in combination with clinical factors. AKI was defined as doubling of serum creatinine or need for acute dialysis. RESULTS: Postoperative AKI occurred in 165 children (60%), with 118 cases (43%) being mild and 47 cases (17%) severe. Preoperative BNP was not associated with increased risk of mild or severe postoperative AKI and did not significantly improve AKI risk prediction when added to clinical models. Preoperative BNP was, however, associated with several clinical outcomes, including length of stay and mechanical ventilation. The results were similar when the analysis was repeated in the subset of children younger than 2 years of age or when the association of postoperative BNP and AKI was evaluated. CONCLUSIONS: Preoperative BNP levels did not predict postoperative AKI in this cohort of children undergoing cardiac operations. Both preoperative and postoperative BNP levels are associated with postoperative outcomes. Clinical Trial Registration at Clinicaltrials.gov as NCT00774137.

Preimplant histologic acute tubular necrosis and allograft outcomes.

BACKGROUND AND OBJECTIVES: The influence of deceased-donor AKI on post-transplant outcomes is poorly understood. The few published studies about deceased-donor preimplant biopsy have reported conflicting results regarding associations between AKI and recipient outcomes. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: This multicenter study aimed to evaluate associations between deceased-donor biopsy reports of acute tubular necrosis (ATN) and delayed graft function (DGF), and secondarily for death-censored graft failure, first adjusting for the kidney donor risk index and then stratifying by donation after cardiac death (DCD) status. RESULTS: Between March 2010 and April 2012, 651 kidneys (369 donors, 4 organ procurement organizations) were biopsied and subsequently transplanted, with ATN reported in 110 (17%). There were 262 recipients (40%) who experienced DGF and 38 (6%) who experienced graft failure. DGF occurred in 45% of kidneys with reported ATN compared with 39% without ATN (P=0.31) resulting in a relative risk (RR) of 1.13 (95% confidence interval [95% CI], 0.9 to 1.43) and a kidney donor risk index-adjusted RR of 1.11 (95% CI, 0.88 to 1.41). There was no significant difference in graft failure for kidneys with versus without ATN (8% versus 5%). In stratified analyses, the adjusted RR for DGF with ATN was 0.97 (95% CI, 0.7 to 1.34) for non-DCD kidneys and 1.59 (95% CI, 1.23 to 2.06) for DCD kidneys (P=0.02 for the interaction between ATN and DCD on the development of DGF). CONCLUSIONS: Despite a modest association with DGF for DCD kidneys, this study reveals no significant associations overall between preimplant biopsy-reported ATN and the outcomes of DGF or graft failure. The potential benefit of more rigorous ATN reporting is unclear, but these findings provide little evidence to suggest that current ATN reports are useful for predicting graft outcomes or deciding to accept or reject allograft offers.

Blood transfusions are associated with urinary biomarkers of kidney injury in cardiac surgery.

OBJECTIVE: Cardiac surgery is a major cause of acute kidney injury. In this setting, receipt of blood transfusions seems to be associated with a higher risk of acute kidney injury, as measured using serum creatinine values. We examined this association further by using urinary biomarkers of kidney injury. METHODS: A total of 1210 adults underwent cardiac surgery and were divided into 3 groups on the basis of the receipt of intraoperative packed red blood cell units: no blood (n = 894), 2 or less packed red blood cell units (n = 206), and more than 2 packed red blood cell units (n = 110). Acute kidney injury was defined as (1) doubling of serum creatinine from the preoperative value; (2) first postoperative urinary interleukin-18 in the fifth quintile; and (3) first postoperative urinary neutrophil gelatinase-associated lipocalin in the fifth quintile. We determined the relative risk for acute kidney injury outcome according to packed red blood cell units group after adjusting for 12 preoperative and surgical variables. By using the Sobel test for mediation analysis, we also evaluated the role of biomarkers in causing acute kidney injury through alternative pathways. RESULTS: Acute kidney injury was more common in those who received more than 2 packed red blood cell units. In patients receiving more than 2 packed red blood cell units, the adjusted relative risks were 2.3 (95% confidence interval, 1.2-4.4, P .01), 1.36 (95% confidence interval, 1.0-1.9, P .05), and 1.34 (95% confidence interval, 1.0-1.8, P .06) for doubling of serum creatinine, urinary interleukin-18 in the fifth quintile (>60 pg/mL), and urinary neutrophil gelatinase-associated lipocalin in the fifth quintile (>102 ng/mL), respectively. Furthermore, the effect of packed red blood cell units transfusion on acute kidney injury was partially mediated by interleukin-18. CONCLUSIONS: Receipt of 2 or more packed red blood cell units during cardiac surgery is associated with a greater risk of acute kidney injury defined by serum creatinine and kidney injury biomarkers.

Disrupted ventromedial prefrontal function, alcohol craving, and subsequent relapse risk.

IMPORTANCE: Alcohol dependence is a chronic relapsing illness; stress, alcohol-related cues, and neutral-relaxing states significantly influence craving and relapse risk. However, neural mechanisms underlying the association between these states and alcohol craving and relapse risk remain unclear. OBJECTIVES: To identify neural correlates associated with alcohol craving and relapse outcomes in 45 treatment-engaged, 4- to 8-week abstinent alcohol-dependent (AD) patients, and to compare brain responses of 30 demographically matched AD patients and 30 healthy control subjects during stress, alcohol, and neutral-relaxing cues. DESIGN: Functional magnetic resonance imaging study while participants were engaging in brief individualized script-driven imagery trials of stress, alcohol cues, and neutral-relaxing scenarios, and a prospective clinical outcome design to assess alcohol relapse 90 days postdischarge from inpatient treatment in the AD group. SETTINGS: Inpatient treatment setting in a community mental health center and hospital-based research unit. PATIENTS: Forty-five recovering AD patients in inpatient treatment for examining relapse, and 30 healthy control subjects demographically matched to 30 AD patients (subgroup of the relapse sample) for group comparisons. INTERVENTION: Twelve-step recovery-based addiction treatment for the patient group. MAIN OUTCOMES AND MEASURES: Brain response, alcohol craving, and relapse outcome measures (time to relapse and relapse severity). RESULTS: Increased ventromedial prefrontal cortex (vmPFC) and anterior cingulate cortex (ACC) activation during neutral-relaxing trials was correlated with high alcohol cue-induced and stress-induced craving in early recovering AD patients (x = 6, y = 43, z = -6; P < .01, whole-brain corrected). This vmPFC/ACC hyperactivity significantly predicted subsequent alcohol relapse, with a hazards ratio greater than 8 for increased relapse risk. Additionally, vmPFC/ACC hyperactivation during neutral trials and reduced activity during stress trials were each predictive of greater days of alcohol used after relapse (P < .01, whole-brain corrected). In contrast, matched control subjects showed the reverse pattern of vmPFC/ACC responses to stress, alcohol cues, and relaxed trials (F = 6.42; P < .01, whole-brain corrected). CONCLUSIONS AND RELEVANCE: Findings indicate that disrupted vmPFC/ACC function plays a role in jeopardizing recovery from alcoholism and may serve as a neural marker to identify those at risk for alcohol relapse.

Genetic modulation of plasma NPY stress response is suppressed in substance abuse: association with clinical outcomes.

BACKGROUND: Neuropeptide Y (NPY) is involved in stress regulation. Genetic variations predict plasma NPY and neural correlates of emotion and stress. We examined whether the functional NPY haplotype modulates stress-induced NPY and anxiety responses, and if plasma NPY stress responses are associated with substance dependence outcomes. METHODS: Thirty-seven treatment-engaged, abstinent substance dependent (SD) patients and 28 healthy controls (HCs) characterized on NPY diplotypes (HH: high expression; HLLL: intermediate/low expression) were exposed to stress, alcohol/drug cues and neutral relaxing cues, using individualized guided imagery, in a 3-session laboratory experiment. Plasma NPY, heart rate and anxiety were assessed. Patients were prospectively followed for 90-days post-treatment to assess relapse outcomes. RESULTS: HH individuals showed significantly lower stress-induced NPY with greater heart rate and anxiety ratings, while the HLLL group showed the reverse pattern of NPY, anxiety and heart rate responses. This differential genetic modulation of NPY stress response was suppressed in the SD group, who showed no stress-related increases in NPY and higher heart rate and greater anxiety, regardless of diplotype. Lower NPY predicted subsequent higher number of days and greater amounts of post-treatment drug use. CONCLUSION: These preliminary findings are the first to document chronic drug abuse influences on NPY diplotype expression where NPY diplotype modulation of stress-related plasma NPY, heart rate and anxiety responses was absent in the substance abuse sample. The finding that lower stress-related NPY is predictive of greater relapse severity provides support for therapeutic development of neuropeptide Y targets in the treatment of substance use disorders.