Association of incident obstructive sleep apnoea with outcomes in a large cohort of US veterans.

RATIONALE: There is a paucity of large cohort studies examining the association of obstructive sleep apnoea (OSA) with clinical outcomes including all-cause mortality, coronary heart disease (CHD), strokes and chronic kidney disease (CKD). OBJECTIVES: We hypothesised that a diagnosis of incident OSA is associated with higher risks of these adverse clinical outcomes. METHODS, MEASUREMENTS: In a nationally representative cohort of over 3 million (n=3 079 514) US veterans (93% male) with baseline estimated glomerular filtration rate (eGFR)≥60 mL/min/1.73 m(2), we examined the association between the diagnosis of incident OSA, treated and untreated with CPAP, and: (1) all-cause mortality, (2) incident CHD, (3) incident strokes, (4)incident CKD defined as eGFR<60 mL/min/1.73 m(2), and (5) slopes of eGFR. MAIN RESULTS: Compared with OSA-negative patients, untreated and treated OSA was associated with 86% higher mortality risk, (adjusted HR and 95% CI 1.86 (1.81 to 1.91) and 35% (1.35 (1.21 to 1.51)), respectively. Similarly, untreated and treated OSA was associated with 3.5 times (3.54 (3.40 to 3.69)) and 3 times (3.06 (2.62 to 3.56)) higher risk of incident CHD; 3.5 times higher risk of incident strokes (3.48 (3.28 to 3.64) and 3.50 (2.92 to 4.19)) for untreated and treated OSA, respectively. The risk of incident CKD was also significantly higher in untreated (2.27 (2.19 to 2.36)) and treated (2.79 (2.48 to 3.13)) patients with OSA. The median (IQR) of the eGFR slope was -0.41 (-2.01 to 0.99), -0.61 (-2.69 to 0.93) and -0.87 (-3.00 to 0.70) mL/min/1.73 m(2) in OSA-negative patients, untreated OSA-positive patients and treated OSA-positive patients, respectively. CONCLUSIONS: In this large and contemporary cohort of more than 3 million US veterans, a diagnosis of incident OSA was associated with higher mortality, incident CHD, stroke and CKD and with faster kidney function decline.

Estimates of kidney function in obese African Americans with chronic kidney disease.

BACKGROUND/AIMS: Methods for assessing glomerular filtration rate (GFR) are controversial in obese individuals. This study compared clinical estimates of GFR in African Americans (AA) with chronic kidney disease (CKD) overall and by body mass index (BMI). METHODS: The estimated GFR was determined in AA with CKD using (1) the 4-variable Modification of Diet in Renal Disease equation (MDRD4), (2) the Cockcroft-Gault equation with ideal, adjusted and total body weight (TBW, with and without normalization for body surface area), and (3) urine collection methods. Differences in mean values and CKD staging were compared for all patients and for subgroups with a BMI above and below 30. RESULTS: The mean GFR by MDRD4 for individuals with a BMI of >30 was 35 ± 14 ml/min/1.73 m(2) and ranged from 32 to 53 ml/min by other methods. Estimates using TBW differed significantly from the MDRD4, a finding not observed for the lower BMI subgroup or when using adjusted weights. The obese patients were more often categorized into a less severe CKD stage, whereas the lower BMI subgroup was commonly grouped into a more severe CKD stage compared to MDRD4 staging. CONCLUSION: Significant variations in estimated GFR between methods exist in the obese. Until other assessment methods are adequately evaluated, clinicians must be critical in applying clinical estimates of kidney function to patient care.

Bacteremia in the chronic spinal cord injury population: risk factors for mortality.

BACKGROUND: Individuals with spinal cord injury (SCI) have a lifelong increased risk of systemic infection, which may be associated with episodes of life-threatening bacteremia. Information concerning specific organisms causing bacteremia, the sites of primary infection, and clinical predictors for mortality are necessary to provide optimal treatment. METHODS: A retrospective review of positive blood cultures collected over a 32-month period in chronic SCI patients treated at the Veterans Affairs Medical Center SCI Unit. RESULTS: One hundred and twenty-three episodes of bacteremia occurred in 63 patients during 83 hospitalizations; 30 patients had multiple episodes of bacteremia. There were 1,644 admissions during this period, yielding an incidence of bacteremia of 7.5% (5.8% after excluding positive cultures that were believed to be caused by contaminants). The patients (31 with paraplegia and 32 with quadriplegia) had a mean age of 59 +/- 2 years, and a mean duration of injury of 23 +/- 2 years. Bladder management technique consisted of indwelling bladder catheter (n = 53), ileal conduit (n = 6), intermittent catheterization (n = 2), and spontaneous voiding (n = 2). Episodes of bacteremia were nosocomial in 89 out of 123 episodes. Multiple debilitating factors were present, including pressure ulcers in 36 out of 63 patients, chronic ventilator dependency in 5 out of 63 patients, recent surgical procedures in 17 out of 63 patients, underlying malignancy in 5 out of 63 patients, and evidence of malnutrition in 29 out of 63 patients (serum albumin concentration < 2.5 g/dL). Early mortality rate (death within 30 days of bacteremia) occurred in 8 out of 63 patients (13%) and late mortality (> 1 month following a bacteremic episode) occurred in 10 additional participants, such that total mortality was 1 8 out of 63 (29%). The sources of bacteremia were urinary tract infection (n = 39), presumed contaminant (n = 28), decubitus ulcers (n = 21), intravascular catheter (n = 19), pneumonia (n = 5), and other (n = 11). Gram-negative rods accounted for 26 out of 39 episodes of bacteremia from a urinary source. Methicillin-resistant Staphylococcus aureus, methicillin-sensitive S aureus, and coagulase-negative staphylococci were the predominant organisms when intravascular catheters or pressure ulcers were the source of bacteremia. CONCLUSION: In this population, bacteremia predominantly was caused by hospital-associated organisms, and occurred mainly in malnourished patients who required hospitalization for major underlying debilitating conditions, particularly pressure ulcers. Chronic indwelling bladder catheters and chronic vascular catheter usage also were highly prevalent in patients with bacteremic episodes. Hypoalbuminemia was the strongest independent predictor for mortality.