Correlation research demonstrates that an inflammatory diet is a risk factor for calcium oxalate renal stone formation.

BACKGROUND AND AIMS: Previous studies have demonstrated associations between the Dietary Inflammatory Index (DII®), an analytical tool which evaluates the inflammatory potential of the diet according to the pro- and anti-inflammatory properties of its components, and renal stone formation. However, these have not comprehensively addressed important parameters such as stone type, gender, DII scores in stone formers (SFs) and healthy controls (Cs) and associations of DII with urine and blood chemistries. These were adopted as the survey parameters for the present study, the purpose of which was to test whether the contributory role of an inflammatory diet on stone formation could be further confirmed. METHODS: 97 calcium oxalate (CaOx) SFs and 63 Cs, matched for age and gender each completed a semi-quantitative food frequency questionnaire from which nutrient composition was computed. These data were used to calculate the DII® score. To control the effect of energy intake, energy-adjusted DII scores were calculated per 1000 kcal consumed (E-DII™). A single blood sample and two consecutive overnight (8h) urine samples were collected from a subset (n = 59 SFs and n = 54 Cs) of the overall number of particpants (n = 160). These were analysed for renal stone risk factors. Data were analysed using regression models fit in R software. RESULTS: E-DII scores were found to fit the data better than DII, so they were used throughout. E-DII scores were significantly more positive (more pro-inflammatory) in SFs than in controls in the combined gender group (-0.34 vs. -1.73, p < 0.0001) and separately in males (-0.43 vs. -1.78, p = 0.01) and females (-0.26 vs. - 1.61, p = 0.05). In blood, a significant negative correlation was seen between E-DII and HDL cholesterol. In urine significant positive correlations were seen between E-DII and each of calcium (ρ = 0.25, p = 0.02), phosphate (ρ = 0.48, p < 0.001), magnesium (ρ = 0.33, p < 0.0001) and uric acid (ρ = 0.27, p = 0.004) concentrations. A significant negative correlation was seen between E-DII and urinary volume ρ = -0.27, p = 0.003). There was no correlation between E-DII scores and the relative supersaturations of urinary CaOx, calcium phosphate (brushite) and uric acid. CONCLUSIONS: Our findings provide hitherto unreported quantitative evidence in support of the notion that the diet of calcium oxalate renal stone patients is significantly more pro-inflammatory than that of healthy controls.

Performance evaluation of the new hematology analyzer UniCel DxH 900.

INTRODUCTION: UniCel DxH900 (Beckman Coulter, Miami, Florida, USA) is a quantitative, multi-parameter, automated hematology analyzer for in vitro diagnostic use in clinical laboratories. The aim of this study was to evaluate the analytical performance of the new DxH900 analyzer to verify its diagnostic and clinical utility in the hematology laboratory of a tertiary care hospital in Spain. The most important and novel feature offered by DxH900 analyzer is providing MDW (monocyte distribution width), a new hematologic parameter which is being clinically validated as an early sepsis indicator with promising results. METHODS: We evaluated imprecision (including MDW), linearity, and carryover of DxH900. Method comparison for cell blood count (CBC) was performed in relation to DxH800 with 100 samples. We compared leukocyte differential (DIFF) from DxH900 with manual 400-cell differential. 390 samples were assessed for flag performance. RESULTS: Results obtained for between days and within-run imprecision were good. DxH900 showed excellent linearity (R = 1.00) over analytical range for white blood cells, red blood cells, hemoglobin, platelets, and reticulocyte count (RET) (R = 0.96) and no significant carryover effect. CBC and RET on the DxH900 correlated well with DxH800 (R ≥ 0.99). Comparison with manual differential showed excellent correlation (R ≥ 0.88), except for basophils. Flagging performance exhibited sensitivity over 90% for majority of alarm messages and very high negative predictive value (over 95%). CONCLUSION: UniCel DxH900 Coulter analyzer provides reliable results and fully comparable to DxH800. DxH900 is an accurate, highly precise analyzer with good analytical performances to be used effectively in high-volume laboratories.

Chronic stress and calcium oxalate stone disease: is it a potential recurrence risk factor?

Chronic emotional stress is associated with increased cortisol release and metabolism disorders. However, few studies have evaluated the influence of chronic stress on calcium oxalate (CaOx) stone disease and its recurrence. A total of 128 patients were enrolled in this case-control study over a period of 20 months. All patients were CaOx stone formers with a recent stone episode (<3 months); 31 were first-time stone formers (FS) and 33 recurrent stone formers (RS). Dimensions of chronic stress were evaluated with self-reported validated questionnaires measuring stressful life events, perceived stress, anxiety, depression, burnout and satisfaction with life. An ad hoc self-reporting questionnaire was designed to evaluate stress-related specifically to stone episodes. Blood and urine samples were collected to determine cortisol levels and urinary composition. In addition, epidemiological data, socioeconomic information, diet and incidences of metabolic syndrome (MS) were reported. Overall, no significant differences were observed in the scores of cases and controls on any of the questionnaires dealing with stress. The number (p < 0.001) and the intensity (p < 0.001) of perceived stressful life events were higher in RS than in FS, but there were no differences between the two groups in other dimensions of stress. RS had higher glucose (p = 0.08), uric acid (p = 0.02), blood cortisol (p = 0.01), and urine calcium levels (p = 0.01) than FS. RS also had lower economic levels (p = 0.02) and more frequent incidences of MS (p = 0.07) than FS. Although no differences were observed in cases and controls among any dimension of chronic stress, the number and intensity of stressful life events were higher in RS than in FS. These differences correlate with variations in blood and urinary levels and with metabolic disorders, indicating an association between chronic stress and risk of recurrent CaOx stone formation.