Reverse epidemiology of lipid-death associations in a cohort of end-stage renal disease patients.

BACKGROUND AND AIMS: Cardiovascular disease is the leading cause of death among end-stage renal disease (ESRD) patients with hypercholesterolemia as a major cause. A few studies have demonstrated counter-intuitive findings known as reverse epidemiology where normal levels of cholesterol are associated with higher levels of mortality. The purpose of this study was to determine if there are reverse epidemiological associations between lipid risk factors and mortality in ESRD patients. METHODS: ESRD (n = 438) patients were recruited from 4 outpatient dialysis units. Patients were tracked for 36 months until study completion or death with mortality status as the outcome measure. RESULTS: Analysis of covariance revealed significant differences at posttest and reverse epidemiological effects for total cholesterol (p = 0.0001), low-density lipoprotein cholesterol (LDL) (p = 0.023), LDL particle number (p = 0.0001), LDL size (p = 0.009), triglycerides (p = 0.0001), and very low-density lipoprotein cholesterol (p = 0.036). A step-wise linear regression revealed weak, but significant predictors of mortality with total cholesterol (ß = 0.263, p = 0.017) and LDL (ß = -0.177, p = 0.045). A Cox death hazard ratio revealed LDL size as a significant predictor of mortality in this study. CONCLUSIONS: Our study discovered reverse epidemiology in a number of lipid variables. Additionally regression revealed that LDL and total cholesterol were predictors of mortality with lower levels being more predictive of death.

Comparison of lipid measures and risk stratification among end-stage renal disease patients.

BACKGROUND: Abnormal lipid profiles are associated with end-stage renal disease (ESRD) which significantly contributes to an accelerated progression of coronary artery disease. The purpose of this study was to examine the relationships between cholesterol measures and differences in risk stratification when using National Cholesterol Education Program, Adult Treatment Panel, Third Report (ATP-III) guidelines, compared with cholesterol particle number and size in ESRD patients. METHODS: Lipid profiles were conducted on 541 ESRD patients who were chronic hemodialysis patients. Lipid profiles were measured using gel electrophoresis and their particle size and concentration measured using nuclear magnetic resonance (NMR) spectroscopy. Correlations and risk stratification were compared between each lipid measure. RESULTS: The findings suggest that low-density lipoprotein (LDL) size does not correlate well with LDL cholesterol and LDL particle number. The findings also suggest a "disconnect" between traditional lipid measures and cholesterol concentration and size when using ATP-III guidelines for risk stratification. CONCLUSIONS: The cholesterol risk designation variances between risk stratification guidelines and the relationships established through Pearson correlations, as illustrated within this patient pool, reveal the complex differences between measures of coronary artery disease risk. These additional patients considered at-risk using NMR technology may help to identify more patients at need for intervention and treatment.

Diagnostic performance of MDCT in identifying closed loop small bowel obstruction.

PURPOSE: To assess the diagnostic performance of MDCT in the diagnosis of closed loop small bowel obstruction. MATERIALS AND METHODS: One hundred fifty patients with CT reports including "small bowel obstruction (SBO)" between 1/30/2011 and 12/4/2012 were included (65 men, 85 women, mean age 63 years). CT examinations were independently and blindly reviewed by five radiologists to determine the presence of closed loop obstruction (CL-SBO) and to assess findings of bowel ischemia. Clinical records were reviewed to determine management and operative findings. Using operative findings as a gold standard, reader agreement for the diagnosis of and the CT findings associated with CLO was analyzed using Pearson's correlation (r). Positive predictive value (PPV) and negative predictive value for the diagnosis of CL-SBO and CT signs of bowel ischemia were analyzed. RESULTS: Eighty-eight of 150 patients underwent operative intervention for SBO and 24/88 were considered CL-SBO operatively. Average reader sensitivity and specificity for CL-SBO was 53 % (95 % CI 44-63 %) and 83 % (95 % CI 79-87 %). Reader agreement on CL-SBO was poor to moderate (K = 0.39-0.63). Reader agreement for CT signs of bowel ischemia resulting in a diagnosis of CL-SBO was weak (r = 0.19-0.32). CONCLUSION: The CT diagnosis of CL-SBO is complex and associated imaging findings have variable sensitivity for predicting a closed loop operative diagnosis. CT can be helpful in excluding a closed loop component in patients with SBO.