Immediate ozone effects on heart rate and repolarisation parameters in potentially susceptible individuals

Elevated ozone levels have been associated with cardiovascular morbidity and mortality. We investigated the effects of ozone on heart rate (HR) and repolarisation parameters in potentially susceptible populations

Reproductive Factors and Serum Uric Acid Levels in Females from the General Population: The KORA F4 Study

Hyperuricemia is associated with an increased risk of metabolic and cardiovascular diseases. There are pronounced sex differences in the levels of uric acid. It is largely unknown whether or not reproductive parameters which induce hormonal changes are responsible for this. We examined if there are associations between reproductive parameters and uric acid levels in a female population-based sample. In this cross-sectional analysis, data of 1530 women aged 32 to 81 years participating in the KORA F4 study, conducted between 2006 and 2008 in Southern Germany were used. Reproductive parameters were obtained by standardized interviews. Uric acid levels were tested by the uricase method. The whole study sample and stratified in pre- and postmenopausal women was analyzed. Menopausal status and earlier age at menarche were associated with higher serum uric acid levels (age-adjusted: p-values 0.003, <0.001 respectively; after multivariable adjustment, including BMI: p-values 0.002, 0.036). A history of oral contraceptive use showed an association with uric acid levels only after multivariable adjustment (p-value 0.009). Hot flushes showed an association with uric acid levels only after age-adjustment (p-value 0.038), but lost significance after adding other confounders. Other reproductive factors, including parity, current or ever use of hormone replacement therapy, current use of oral contraceptives, hysterectomy, bilateral oophorectomy, or depressive mood related to menopausal transition were not associated with uric acid levels. Postmenopausal status, earlier age at menarche and a history of oral contraceptive use were independently associated with higher serum uric acid concentrations in women from the general population. Further studies, especially longitudinal population-based studies investigating the relationship of female reproductive parameters with uric acid levels are necessary to confirm our findings

Differences between Human Plasma and Serum Metabolite Profiles

BACKGROUND: Human plasma and serum are widely used matrices in clinical and biological studies. However, different collecting procedures and the coagulation cascade influence concentrations of both proteins and metabolites in these matrices. The effects on metabolite concentration profiles have not been fully characterized. METHODOLOGY/PRINCIPAL FINDINGS: We analyzed the concentrations of 163 metabolites in plasma and serum samples collected simultaneously from 377 fasting individuals. To ensure data quality, 41 metabolites with low measurement stability were excluded from further analysis. In addition, plasma and corresponding serum samples from 83 individuals were re-measured in the same plates and mean correlation coefficients (r) of all metabolites between the duplicates were 0.83 and 0.80 in plasma and serum, respectively, indicating significantly better stability of plasma compared to serum (p = 0.01). Metabolite profiles from plasma and serum were clearly distinct with 104 metabolites showing significantly higher concentrations in serum. In particular, 9 metabolites showed relative concentration differences larger than 20%. Despite differences in absolute concentration between the two matrices, for most metabolites the overall correlation was high (mean r = 0.81±0.10), which reflects a proportional change in concentration. Furthermore, when two groups of individuals with different phenotypes were compared with each other using both matrices, more metabolites with significantly different concentrations could be identified in serum than in plasma. For example, when 51 type 2 diabetes (T2D) patients were compared with 326 non-T2D individuals, 15 more significantly different metabolites were found in serum, in addition to the 25 common to both matrices. CONCLUSIONS/SIGNIFICANCE: Our study shows that reproducibility was good in both plasma and serum, and better in plasma. Furthermore, as long as the same blood preparation procedure is used, either matrix should generate similar results in clinical and biological studies. The higher metabolite concentrations in serum, however, make it possible to provide more sensitive results in biomarker detection

Immediate ozone effects on heart rate and repolarisation parameters in potentially susceptible individuals

Elevated ozone levels have been associated with cardiovascular morbidity and mortality. We investigated the effects of ozone on heart rate (HR) and repolarisation parameters in potentially susceptible populations

Characteristics of the study population, mean (SD) and prevalences (%) of variables according to quartiles of uric acid, KORA F4 study (women 32–81 years).

<p>Abbreviations: Q: quartile, BMI: body mass index, SD: standard deviation, OC: oral contraceptives, HRT: hormone replacement therapy, HDL: high density lipoprotein.</p><p>Data are expressed as mean (SD) or percentages respectively.</p><p>p-value: chi-square test was performed to test the difference between the parameters and continuous uric acid levels.</p>a<p>defined as use of antihypertensive medication, being aware of having hypertension or blood pressure values greater than 140/90 mmHg.</p>b<p>due to the skewed distribution of creatinine, the median and interquartile range is shown.</p>c<p>defined as postmenopausal women and women under hormone replacement therapy.</p>d<p>n = 693, due to missing values of age at menopause.</p

Mean uric acid levels stratified by reproductive parameters, the KORA F4 study (N = 1530).

<p>Abbreviations: CI: Confidence Interval, BMI: Body mass index, lsmean: least square mean.</p>*<p>the p-values (linear model) are reported for age at menarche and parity as continuous variable.</p><p>Model 1: adjusted for age (in years).</p><p>Model 2: adjusted for age (in years) and BMI (kg/m²).</p><p>Model 3: adjusted for age (in years), BMI (kg/m²), serum creatinine (mg/dl), current use of uricosuric or uricostatic medication (yes/no), alcohol consumption (>20 g/d in %), current hypertension (yes/no), HDL cholesterol (mg/dl), total cholesterol (mg/dl), history of diabetes (yes/no) and education (years).</p

Reproductive parameters and uric acid levels in postmenopausal women, including women currently under hormone replacement therapy, the KORA F4 study (n = 959).

<p>Abbreviations: CI: Confidence Interval, BMI: Body mass index, lsmean: least square means.</p>*<p>the p-values (linear model) are reported for age at menarche and parity as continuous variable.</p><p>Model 1: adjusted for age (in years).</p><p>Model 2: adjusted for age (in years) and BMI (kg/m²).</p><p>Model 3: adjusted for age (in years), BMI (kg/m²), serum creatinine (mg/dl), current use of uricosuric or uricostatic medication (yes/no), alcohol consumption (>20 g/d in %), current hypertension (yes/no), HDL cholesterol (mg/dl), total cholesterol (mg/dl), history of diabetes (yes/no) and education (years).</p>a<p>n = 693, due to missing values of age at menopause.</p