Sex and the Risk of AKI Following Cardio-thoracic Surgery: A Meta-Analysis.

BACKGROUND AND OBJECTIVES: Being a woman is a well established risk factor for the development of cardiothoracic surgery-associated AKI. In striking contrast, women are less likely to develop AKI associated with noncardiac surgical procedures than men. In an attempt to ascertain why being a woman might be protective for ischemic AKI after general surgery but deleterious in patients undergoing cardiothoracic surgery, we examined cardiothoracic surgery-associated AKI in greater detail. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: We performed a systematic review and meta-analysis of cardiothoracic surgery-associated AKI studies published between January of 1978 and December of 2015 to further explore the relationship between sex and cardiothoracic surgery-associated AKI. RESULTS: Sixty-four studies were identified that provided sex-specific data regarding the incidence of cardiothoracic surgery-associated AKI among 1,057,412 subjects. Using univariate analysis, women were more likely than men to develop AKI postoperatively (odds ratio, 1.21; 95% confidence interval, 1.09 to 1.33; P<0.001). However, when the analysis was restricted to the 120,464 subjects reported in 29 studies that used the Acute Kidney Injury Network criteria, the RIFLE criteria, or the Kidney Disease Improving Global Outcomes criteria to define AKI, there was no significant sex-related difference in risk. Seventeen studies used multivariate analysis to assess risk factors for cardiothoracic surgery-associated AKI and provided sex-specific odd ratios. Among the 1,587,181 individuals included in these studies, the risk of developing cardiothoracic surgery-associated AKI was not significantly associated with sex (odds ratio, 1.04; 95% confidence interval, 0.92 to 1.19; P=0.51). However, when the analysis was restricted to the 5106 subjects reported in four studies that used the Acute Kidney Injury Network criteria to define AKI, the risk of developing AKI was significantly lower in women compared with in men (odds ratio, 0.75; 95% confidence interval, 0.65 to 0.87; P<0.001). CONCLUSIONS: Our systematic review and meta-analysis contradict the generally held consensus that being a woman is an independent risk factor for the development of cardiothoracic surgery-associated AKI.

Risk of lymphoma in patients with inflammatory bowel disease treated with azathioprine and 6-mercaptopurine: a meta-analysis.

BACKGROUND & AIMS: Thiopurine therapy for inflammatory bowel disease (IBD) has been associated with increased risk for lymphoma. We estimated the relative risk of lymphoma in patients with IBD exposed to thiopurines and compared relative risk values derived from population-based studies with those from referral center-based studies. We investigated whether active use increased risk compared with past use, and whether sex, age, or duration of use affects risk of lymphoma. METHODS: We searched MEDLINE, EMBASE, and Cochrane databases, as well as conference abstracts and international publications, for the terms "6-MP and lymphoma," "6-mercaptopurine and lymphoma," "thiopurines and lymphoma," "azathioprine and cancer and IBD," "azathioprine and malignancy and IBD," "azathioprine and lymphoma," and "lymphoproliferative and thiopurines." Pooled standardized incidence ratios (SIRs) and 95% confidence intervals (CIs) were estimated. The deviance statistic from Poisson models was used to calculate heterogeneity. RESULTS: Eighteen studies (among 4383 citations) met our inclusion criteria. Overall, the SIR for lymphoma was 4.92 (95% CI, 3.10-7.78), ranging from 2.80 (95% CI, 1.82-4.32) in 8 population studies to 9.24 (95% CI, 4.69-18.2) in 10 referral studies. Population studies demonstrated an increased risk among current users (SIR = 5.71; 95% CI, 3.72-10.1) but not former users (SIR = 1.42; 95% CI, 0.86-2.34). Level of risk became significant after 1 year of exposure. Men have a greater risk than women (relative risk = 1.98; P < .05); both sexes were at increased risk for lymphoma (SIR for men = 4.50; 95% CI = 3.71-5.40 and SIR for women = 2.29; 95% CI = 1.69-3.05). Patients younger than 30 years had the highest relative risk (SIR = 6.99; 95% CI, 2.99-16.4); younger men had the highest risk. The absolute risk was highest in patients older than 50 years (1:354 cases per patient-year, with a relative risk of 4.78). CONCLUSIONS: Compared with studies from referral centers, population-based studies of IBD patients show a lower but significantly increased risk of lymphoma among patients taking thiopurines. The increased risk does not appear to persist after discontinuation of therapy. Patients over 50 have the highest absolute risk of lymphoma per year on thiopurines, while men under 35 may also be a high risk group. More study is needed to precisely understand groups highest at risk. The risks of lymphoma and potential benefits of therapy should be considered for all patients with IBD.

A Rare Presentation of AKI: Gastric Infiltration of the Bladder Wall.

We describe the case of a man who presented with back pain and acute kidney injury and was found to have bilateral ureteral obstruction, which initially corrected with ureteral stents. Imaging studies showed thickening of the bladder. Shortly thereafter, he developed obstructive jaundice, pancreatitis, recurrence of renal failure, and was diagnosed with advanced gastric cancer after a laparotomy revealed peritoneal carcinomatosis. The patient deteriorated rapidly after diagnosis. While peritoneal carcinomatosis, ureteral metastases, and extrinsic ureteral compression have been recognized in gastric cancer, obstructive renal failure due to tumor infiltration of the bladder wall is seldom described. We present this case as an unusual cause of acute renal failure and presentation of gastric cancer.