Gut Microbiota-Dependent Trimethylamine N-Oxide (TMAO) Pathway Contributes to Both Development of Renal Insufficiency and Mortality Risk in Chronic Kidney Disease

RATIONALE: Trimethylamine-N-oxide (TMAO), a gut microbial-dependent metabolite of dietary choline, phosphatidylcholine (lecithin), and l-carnitine, is elevated in chronic kidney diseases (CKD) and associated with coronary artery disease pathogenesis. OBJECTIVE: To both investigate the clinical prognostic value of TMAO in subjects with versus without CKD, and test the hypothesis that TMAO plays a direct contributory role in the development and progression of renal dysfunction. METHODS AND RESULTS: We first examined the relationship between fasting plasma TMAO and all-cause mortality over 5-year follow-up in 521 stable subjects with CKD (estimated glomerular filtration rate, \u3c60 mL/min per 1.73 m(2)). Median TMAO level among CKD subjects was 7.9 μmol/L (interquartile range, 5.2-12.4 μmol/L), which was markedly higher (P\u3c0.001) than in non-CKD subjects (n=3166). Within CKD subjects, higher (fourth versus first quartile) plasma TMAO level was associated with a 2.8-fold increased mortality risk. After adjustments for traditional risk factors, high-sensitivity C-reactive protein, estimated glomerular filtration rate, elevated TMAO levels remained predictive of 5-year mortality risk (hazard ratio, 1.93; 95% confidence interval, 1.13-3.29; P\u3c0.05). TMAO provided significant incremental prognostic value (net reclassification index, 17.26%; P\u3c0.001 and differences in area under receiver operator characteristic curve, 63.26% versus 65.95%; P=0.036). Among non-CKD subjects, elevated TMAO levels portend poorer prognosis within cohorts of high and low cystatin C. In animal models, elevated dietary choline or TMAO directly led to progressive renal tubulointerstitial fibrosis and dysfunction. CONCLUSIONS: Plasma TMAO levels are both elevated in patients with CKD and portend poorer long-term survival. Chronic dietary exposures that increase TMAO directly contributes to progressive renal fibrosis and dysfunction in animal models

Risk of pre-eclampsia in women taking metformin: a systematic review and meta-analysis

© 2017 Diabetes UK Aims: To perform meta-analyses of studies evaluating the risk of pre-eclampsia in high-risk insulin-resistant women taking metformin prior to, or during pregnancy. Methods: A search was conducted of the Medline, EMBASE, Web of Science and Scopus databases. Both randomized controlled trials and prospective observational cohort studies of metformin treatment vs. placebo/control or insulin either prior to or during pregnancy were selected. The main outcome measure was the incidence of pre-eclampsia in each treatment group. Results: Overall, in five randomized controlled trials comparing metformin treatment (n = 611) with placebo/control (n = 609), no difference in the risk of pre-eclampsia was found [combined/pooled risk ratio (RR), 0.86 (95% CI 0.33–2.26); P = 0.76; I2 = 66%]. Meta-analysis of four cohort studies again showed no significant effect [RR, 1.21 (95% CI 0.56–2.61); P = 0.62; I2 = 30%]. A meta-analysis of eight randomized controlled trials comparing metformin (n = 838) with insulin (n = 836), however, showed a reduced risk of pre-eclampsia with metformin [RR, 0.68 (95% CI 0.48–0.95); P = 0.02; I2 = 0%]. No heterogeneity was present in the metformin vs. insulin analysis of randomized controlled trials, whereas high levels of heterogeneity were present in studies comparing metformin with placebo/control. Pre-eclampsia was a secondary outcome in most of the studies. The mean weight gain from time of enrolment to delivery was lower in the metformin group (P = 0.05, metformin vs. placebo; P = 0.004, metformin vs. insulin). Conclusions: In studies randomizing pregnant women to glucose-lowering therapy, metformin was associated with lower gestational weight gain and a lower risk of pre-eclampsia compared with insulin

Altered cardiac autonomic nervous function in depression

Background:Depression is an independent risk factor for coronary artery disease. Autonomic instability may play a mediating or moderating role in this relationship; however this is not well understood. The objective of this study was to explore cardiac autonomic function and cardiac arrhythmia in depression, the correlation between depression severity and Heart Rate Variability (HRV) related indices, and the prevalence of arrhythmia.Methods:Individuals (n = 53) with major depression as assessed by the Diagnostic and Statistical Manual of Mental Disorders, who had a Hamilton Rating Scale for Depression (HAMD) score ≥20 and a Zung Self-Rating Depression Scale score > 53 were compared to 53 healthy individuals, matched for age and gender. Multichannel Electrocardiograph ECG-92C data were collected over 24 hours. Long-term changes in HRV were used to assess the following vagally mediated changes in autonomic tone, expressed as time domain indices: Standard deviation of the NN intervals (SDNN), standard deviation of 5 min averaged NN intervals (SDANN), Root Mean Square of the Successive Differences (RMSSD) and percentage of NN intervals > 50 ms different from preceding interval (pNN50). Pearson’s correlations were conducted to explore the strength of the association between depression severity (using the SDS and HRV related indices, specifically SDNN and low frequency domain / high frequency domain (LF/HF)).Results:The values of SDNN, SDANN, RMSSD, PNN50 and HF were lower in the depression group compared to the control group (P<.05). The mean value of the LF in the depression group was higher than the in control group (P<.05). Furthermore the ratio of LF/HF was higher among the depression group than the control group (P<.05). A linear relationship was shown to exist between the severity of the depression and HRV indices. In the depression group, the prevalence of arrhythmia was significantly higher than in the control group (P<.05), particularly supraventricular arrhythmias.Conclusions:Our findings suggest that depression is accompanied by dysfunction of the cardiac autonomic nervous system, and further, that depression severity is linked to severity of this dysfunction. Individuals with depression appear to be susceptible to premature atrial and/or ventricular disease

Differential Expression of Vegfr-2 and Its Soluble Form in Preeclampsia

Several studies have suggested that the main features of preeclampsia (PE) are consequences of endothelial dysfunction related to excess circulating anti-angiogenic factors, most notably, soluble sVEGFR-1 (also known as sFlt-1) and soluble endoglin (sEng), as well as to decreased PlGF. Recently, soluble VEGF type 2 receptor (sVEGFR-2) has emerged as a crucial regulator of lymphangiogenesis. To date, however, there is a paucity of information on the changes of VEGFR-2 that occur during the clinical onset of PE. Therefore, the aim of our study was to characterize the plasma levels of VEGFR-2 in PE patients and to perform VEGFR-2 immunolocalization in placenta.By ELISA, we observed that the VEGFR-2 plasma levels were reduced during PE compared with normal gestational age matched pregnancies, whereas the VEGFR-1 and Eng plasma levels were increased. The dramatic drop in the VEGFR-1 levels shortly after delivery confirmed its placental origin. In contrast, the plasma levels of Eng and VEGFR-2 decreased only moderately during the early postpartum period. An RT-PCR analysis showed that the relative levels of VEGFR-1, sVEGFR-1 and Eng mRNA were increased in the placentas of women with severe PE. The relative levels of VEGFR-2 mRNA as well as expressing cells, were similar in both groups. We also made the novel finding that a recently described alternatively spliced VEGFR-2 mRNA variant was present at lower relative levels in the preeclamptic placentas.Our results indicate that the plasma levels of anti-angiogenic factors, particularly VEGFR-1 and VEGFR-2, behave in different ways after delivery. The rapid decrease in plasma VEGFR-1 levels appears to be a consequence of the delivery of the placenta. The persistent circulating levels of VEGFR-2 suggest a maternal endothelial origin of this peptide. The decreased VEGFR-2 plasma levels in preeclamptic women may serve as a marker of endothelial dysfunction

Delivery of a Small for Gestational Age Infant and Greater Maternal Risk of Ischemic Heart Disease

Background: Delivery of a small for gestational age (SGA) infant has been associated with increased maternal risk of ischemic heart disease (IHD). It is uncertain whether giving birth to SGA infant is a specific determinant of later IHD, independent of other risk factors, or a marker of general poor health. The purpose of this study was to investigate the association between delivery of a SGA infant and maternal risk for IHD in relation to traditional IHD risk factors. Methods and Findings: Risk of maternal IHD was evaluated in a population based cross-sectional study of 6,608 women with a prior live term birth who participated in the National Health and Nutrition Examination Survey (1999–2006), a probability sample of the U.S. population. Sequence of events was determined from age at last live birth and at diagnosis of IHD. Delivery of a SGA infant is strongly associated with greater maternal risk for IHD (age adjusted OR; 95 % CI: 1.8; 1.2, 2.9; p = 0.012). The association was independent of the family history of IHD, stroke, hypertension and diabetes (family historyadjusted OR; 95 % CI: 1.9; 1.2, 3.0; p = 0.011) as well as other risk factors for IHD (risk factor-adjusted OR; 95 % CI: 1.7; 1.1, 2.7; p = 0.025). Delivery of a SGA infant was associated with earlier onset of IHD and preceded it by a median of 30 (interquartile range: 20, 36) years. Conclusions: Giving birth to a SGA infant is strongly and independently associated with IHD and a potential risk factor that precedes IHD by decades. A pregnancy that produces a SGA infant may induce long-term cardiovascular changes tha

Online direct-to-consumer messages about non-invasive prenatal genetic testing

Non-invasive prenatal testing (NIPT) has been integrated into clinical care at a time when patients and healthcare providers increasingly utilize the internet to access health information. This study evaluated online direct-to-consumer information about NIPT produced by commercial laboratories accessible to both patients and healthcare providers. A coding checklist captured areas to describe content and assess concordance with clinical guidelines. We found that the information presented about NIPT is highly variable, both within a single website and broadly across all websites. Variability was noted in how NIPT is characterized, including test characteristics and indications. All laboratories offer NIPT to test for common sex chromosome aneuploidies, although there is a lack of consistency regarding the conditions offered and information provided about each. Although indicated for a subset of women at increased risk of aneuploidy, some laboratories describe the use of NIPT for all pregnant women. A subset of laboratories offers screening for microdeletions, although clinical practice guidelines do not yet recommend for general use for this indication. None of the online materials addressed the ethical issues associated with NIPT. This study highlights the need for clear, consistent, and evidence-based materials to educate patients and healthcare providers about the current and emerging applications of NIPT

It’s More Than a Blood Test: Patients’ Perspectives on Noninvasive Prenatal Testing

Noninvasive prenatal testing (NIPT) offers pregnant women a new risk assessment tool for fetal aneuploidy that is superior to conventional screening tests. We conducted focus groups with women who were currently pregnant or had recently delivered in the past year to characterize their perspectives about NIPT and to explore factors they would consider during decision making about its use. Women identified accuracy, early timing, testing ease, and determination of fetal sex as advantages of NIPT over other screens, and the noninvasive method of NIPT as an advantage over diagnostic tests. False positive and false negative results, anxiety, cost and insurance coverage were seen as disadvantages of NIPT. Women who do not want fetal aneuploidy information most likely will not undergo NIPT, despite its advantages over other screening tests. However, given its advantages, the decision to have NIPT is straightforward for women who want genetic information about the fetus. Women emphasized the need to make autonomous, private, and informed choices about NIPT, as they would with any prenatal genetic testing option. These perspectives may guide clinicians to conduct effective and clinically relevant counseling with pregnant women who consider utilizing this new genetic technology

It’s More Than a Blood Test: Patients’ Perspectives on Noninvasive Prenatal Testing

Noninvasive prenatal testing (NIPT) offers pregnant women a new risk assessment tool for fetal aneuploidy that is superior to conventional screening tests. We conducted focus groups with women who were currently pregnant or had recently delivered in the past year to characterize their perspectives about NIPT and to explore factors they would consider during decision making about its use. Women identified accuracy, early timing, testing ease, and determination of fetal sex as advantages of NIPT over other screens, and the noninvasive method of NIPT as an advantage over diagnostic tests. False positive and false negative results, anxiety, cost and insurance coverage were seen as disadvantages of NIPT. Women who do not want fetal aneuploidy information most likely will not undergo NIPT, despite its advantages over other screening tests. However, given its advantages, the decision to have NIPT is straightforward for women who want genetic information about the fetus. Women emphasized the need to make autonomous, private, and informed choices about NIPT, as they would with any prenatal genetic testing option. These perspectives may guide clinicians to conduct effective and clinically relevant counseling with pregnant women who consider utilizing this new genetic technology