Marital distress, depression, and a leaky gut: Translocation of bacterial endotoxin as a pathway to inflammation.

BACKGROUND: Marital distress and depression work in tandem to escalate risks for inflammation-related disorders. Translocation of bacterial endotoxin (lipopolysaccharide, LPS) from the gut microbiota to blood circulation stimulates systemic inflammatory responses. METHODS: To investigate increased gut permeability (a "leaky gut") as one potential mechanistic pathway from marital distress and depression to heightened inflammation, this secondary analysis of a double-blind, randomized crossover study examined serial assessments of two endotoxin biomarkers, LPS-binding protein (LBP) and soluble CD14 (sCD14), as well as C-reactive protein (CRP), interleukin 6 (IL-6), and tumor necrosis factor alpha (TNF-α) during two separate 9.5 h visits. The 43 (N = 86) healthy married couples, ages 24-61 (mean = 38.22), discussed a marital disagreement during both visits; behavioral coding of these interactions provided data on hostile marital behaviors, a hallmark of marital distress. The Structured Diagnostic Interview for DSM-IV assessed participants' mood disorder history. RESULTS: Participants with more hostile marital interactions had higher LBP than those who were less hostile. Additionally, the combination of more hostile marital interactions with a mood disorder history was associated with higher LBP/sCD14 ratios. Higher LBP and LBP/sCD14 were associated with greater CRP production; for example, only 21% of low LBP participants (lowest quartile) had average CRP across the day > 3, compared to 79% of those in the highest quartile. Higher sCD14 was associated with higher IL-6. CONCLUSIONS: These bacterial LPS translocation data illustrate how a distressed marriage and a mood disorder history can promote a proinflammatory milieu through increased gut permeability, thus fueling inflammation-related disorders.

Risk factors and survival in patients with respiratory failure after cardiac operations.

BACKGROUND: Respiratory failure is a known complication of cardiac operations and contributes to postoperative morbidity and death. This study assessed the relevance of risk factors in the development of respiratory failure, defined as postoperative ventilation exceeding 48 hours, and looked at the effect of respiratory failure on short-term and long-term mortality rates. METHODS: De-identified data for patients who underwent cardiac surgical procedures at The Prince Charles Hospital between January 2002 and December 2007 were collected prospectively and analyzed using logistic regression to identify significant risk factors associated with respiratory failure. Long-term mortality data were analyzed for patients who underwent operations between 1994 and 2005 using Kaplan-Meier survival curves. RESULTS: The risk factor analysis included 7,440 patients. Identified risk factors for respiratory failure included critical preoperative state, neurologic dysfunction, poor left ventricular function, active endocarditis, chronic obstructive pulmonary disease, elevated preoperative creatinine, previous cardiac operation, and age. Survival was assessed in 18,488 patients and demonstrated increased short-term and long-term mortality rates when respiratory failure developed and increased mortality rates with increasing duration of respiratory failure. CONCLUSIONS: Respiratory failure is complication of cardiac operations associated with increased mortality and cost. Identification of patients at risk of respiratory failure may help select surgical candidates and aid resource planning and optimization.