Long-term decline of renal function in patients with resistant and non-resistant arterial hypertension

Background

The negative effect of arterial hypertension on renal function is well known. Until present, the detrimental effect of resistant arterial hypertension (RAH) on kidneys was not clearly defined.

Purpose

To assess the deterioration of renal function in patients with RAH in comparison to patients with non-resistant arterial hypertension (AH) during a long term follow-up.

Methods

We retrospectively reviewed records of 307 patients followed between May 2007 and January 2019 in an Hypertension Excellence Centre of a tertiary hospital. In all patients we assessed basic demographic characteristics, co-morbidities, laboratory findings, secondary causes of AH, medication, blood pressure including ambulatory blood pressure monitoring, studies and invasive procedures (CT, MRI, coronarography). We statistically evaluated differences in both groups and compared the decline of renal function.

Results

160 patients had resistant and 147 patients non-resistant hypertension. Patients were followed for a mean of 6 years. Patients with RAH were older (58.1±10.8 years vs. 51±13 years), more frequently diabetics (39.3% vs. 8.7%), had more frequent exposure to diagnostic studies and invasive procedures (86,5% vs. 64%).

Age at baseline visit and diabetes mellitus were established as statistically significant independent risk factors. Linear mixed effect model adjusted to age and diabetes demonstrated that patients with RAH have increased decline of renal function than patients with AH: patients with AH had mean increase of creatinine +0.24 μmol/l per year, while patients with RAH + 2.12 μmol/l per year (P=0.005). Similarly the decrease of eGFR in patients with AH was −0.66 compared to −1.5 mL/s/1.73 m2 per year in patients with RAH (P=0.005).

Figures 1 and 2 show the difference in mean slope of creatinine and eGFR in patients with resistant and non-resistant hypertension (based on linear mixed effect models)).

Conclusion

Patients with resistant hypertension had faster decline of renal function in comparison to patients with non-resistant hypertension independently on age and diabetes. Further studies are needed to determine the key factors affecting renal function decline in both subgroups.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): University Hospital Olomouc, Palacky University Olomouc, Faculty of Medicine, Czech Republic

Effects of different pharmaceutical residues on embryos of fish species native to Central Europe

Environmental concentrations of pharmacologically active substances are increasing dramatically throughout the world, to the point where they are now considered a serious threat to the aquatic environment. This high occurrence of pharmaceutical residues in the aquatic environment is due to an increase in i) the prescription and consumption of drugs, and ii) their subsequent discharge into wastewater and its imperfect purification in wastewater treatment plants. Recent surveys have clearly shown that such substances can have serious negative effects on non-target organisms. In the present study, we tested the effects of several commonly used pharmaceuticals, such as antidepressants, analgesics and antibiotics, on the embryonic stages of different fishes. Specifically, we applied concentration ranges of tramadol, enrofloxacin and nortriptylined on a common toxicological model organism, the zebrafish (Danio rerio), and other species native to Central European freshwaters, i.e. common carp (Cyprinus carpio), catfish (Silurus glanis) and tench (Tinca tinca). Our results show that, though malformation and negative impacts on hatching and mortality were only observed at the highest test concentrations, gene expression indicated that even low environmentally relevant concentrations (0.1 μg/L) can cause significant changes in early development of embryo.

Foodborne fluoxetine impacts the immune response in rainbow trout (Oncorhynchus mykkis)

The aim of this study was to reveal the effects of foodborne fluoxetine on morphological and condition profile, hematological profile, biochemical and oxidative stress indices on juvenile rainbow trout. The study was performed according to OECD Guideline No. 215. Fluoxetine was incorporated into Biomar 921 pellets at a dose of 0.047 mg/kg (environmental concentration), 0.577 mg/kg and 6.7 mg/kg. There was statistically significant change in hematological profile, including an increasing trend in neutrophil/lymphocyte ratio and a decreasing trend in the number of lymphocytes. Measurements of oxidative stress indicated decreased activity of the detoxifying enzyme glutathione-S-transferase in the liver and kidney. However, the measurement of GR, GPx, CAT, SOD activity, and TBARS showed no changes. Histopathological examination revealed damage to the proximal tubules of caudal kidney in exposed groups. This study confirms that fluoxetine has a significant effect on immune response.

Potential risks of substituting estimated glomerular filtration rate for estimated creatinine clearance for dosing of direct oral anticoagulants in atrial fibrillation and chronic kidney disease

Background

In the clinical trials with direct oral anticoagulants (DOAC) estimates of creatinine clearance (CrCl) with Cockcroft-Gault equation were used to assess renal functions. Recently, most laboratories report renal function estimated with the Modification of Diet in Renal Disease (MDRD) or Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations, which may lead to impaired dosing of DOACs by physicians.

Purpose

To compare estimated glomerular filtration rate and estimated creatinine clearance in a large group of patients with atrial fibrillation and chronic kidney disease.

Methods

Physicians from 423 institutions in the Czech Republic were asked to enroll 5 consecutive outpatients with atrial fibrillation (AF) treated by a DOAC with stage 3 chronic kidney disease and glomerular filtration rate (eGFR) 30–59 ml/min estimated by MDRD or CKD EPI equations into the registry. Besides eGFR, serum creatinine values were recorded and CrCl calculated by the Cockroft-Gault formula. Results of CrCl and eGFR obtained in individual patients were compared and statistically analyzed using two-sample t-test.

Results

A total of 2115 patients were enrolled. Mean CrCl was 47.43 ml/min, mean eGFR calculated by MDRD and CKD-EPI was lower 43.88 and 43.53 ml/min (P for difference <0.001 for both). Mean difference between CrCl and eGFR in individual patients calculated by MDRD and CKD-EPI was 8.8 and 9.41 ml/min. A difference beween CrCl and eGFR >10 ml/min was found in 31.5% and 34.8% patients when using MDRD and CKD-EPI formulas. The respective differences between CrCl and eGFR between 4.1 and 10 ml/min were found in 28.5% (MDRD) and 30.8% (CKD-EPI). At CrCl above or below 50 ml/min, 24.0% and 24.2% were misclassified when using eGFR calculated by MDRD and CKD-EPI. At CrCl above or below 30 ml/min, 9.8% (MDRD) and 10.0% (CKD-EPI) patients were misclassified (please see Figures).

Conclusions

When eGFR estimated by MDRD or CKD-EPI is used to assess renal function and guide DOAC dosing instead of CrCl calculated by the Cockroft-Gault formula in patients with AF and stage 3 CKD, more than a third of patients is misclassified and wrong DOAC dose can be recommended.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Boehringer-Ingelheim Differences between CrCl and CKD-EPIDifferences between CrCl and MDRD

The effect of foodborne sertraline on rainbow trout (Oncorhynchus mykiss)

The worldwide consumption of antidepressants is raising as well as their concentrations in the aquatic environment. This increases the risk of food chain contamination and bioaccumulation in aquatic biota. The aim of this study was to describe a potential risk of sertraline as a pollutant from water environment, wherein rainbow trout (Oncorhynchus mykiss) has been chosen as the test organism, because predatory fish are on the top of the food chain in the aquatic environment. The effects of foodborne sertraline were tested on rainbow trout during a 28-day toxicity test according to OECD 215 method. Sertraline was incorporated in commercial feed at a dose of 4.4 µg/kg (environmental concentration), 42 µg/kg and 400 µg/kg. The results confirmed that sertraline has a significant effect on fish behaviour, resulting in suppression of the escape reflex and increased resistance to stress. Moreover, increased Fultońs condition factor was found in fish fed with the highest concentration of sertraline. Haematological analysis revealed a statistically significant increase in the number of neutrophilic bands and neutrophil/lymphocyte ratio, and decreased number of lymphocytes. The results of biochemical examination showed a statistically significant decrease in ammonia and lactate concentrations and histological examination revealed changes in gills and caudal kidney. Although sertraline reduces stress in fish, the decline in nonspecific immunity is a risk to fish population stability.

1418Adverse effects of spironolactone in long-term treatment of resistant arterial hypertension

Background

Spironolactone is recommended as a fourth line antihypertensive drug by current hypertension guidelines. This drug had relatively few adverse effects in short term clinical trials, but data about their occurrence during long-term treatment of resistant hypertension are scarce.

Purpose

To evaluate the occurrence and type of adverse effects of spironolactone during long-term treatment and their possible clinical and laboratory predictors.

Methods

We prospectively followed 274 patients with resistant arterial hypertension who started treatment with spironolactone between September 2007 and December 2016. The duration of spironolactone use, its dose, the incidence of adverse events, blood pressure, and laboratory findings were recorded at baseline and during the last clinical examination.

Results

Patients were followed for an average of 35 (± 29) months, the mean dose of spironolactone was 27.5 mg/day. Adverse effects occurred in 72 patients (26.3%) and in 61 (84.7%) lead to discontinuation of spironolactone. The most common adverse reactions were gynaecomastia (30.6%), hyperkalaemia (30.6%) and symptomatic hypotension (26.4%). The mean duration of spironolactone treatment before their occurrence was 25 (± 27) months. According to the Kaplan-Meier curve, the median for the incidence of adverse events would be 97 months (91.5–102.5 months), i.e. 50% of patients could be treated with no adverse events for more than 8 years. Adverse events were more common in the elderly (hazard ratio – HR 1.38, P=0.007), patients with higher baseline serum creatinine (HR 1.12, P=0.035) and patients taking angiotensin receptor blockers (HR 1.65, P=0.040).

Kaplan-Meier estimate – adverse events

Conclusion

During long-term treatment of resistant hypertension with spironolactone, more than a quarter of patients experience adverse reactions that usually require discontinuation of spironolactone.

Acknowledgement/Funding

Supported by the grants of Palacký University in Olomouc Nr. IGA_LF_2016_038 and IGA_LF_2017_029.

Sleep apnoea in patients with nocturnal hypertension - a multicenter study in the Czech Republic

Sleep apnoea (SA) is common in patients with hypertension. Nowadays, limited data on the prevalence of SA in nocturnal hypertension (NH) exist. Therefore, we studied the occurrence of SA in Czech patients and its association with 24-h ambulatory blood pressure monitoring (ABPM), breathing disturbances in sleep, anthropometric data, Mallampati score and Epworth sleepiness scale (ESS) using the Apnea Link device. Undiagnosed SA was found in 72.9 % patients (29.3 % mild, 26.6 % moderate, 17.0 % severe) of 188 patients with NH measured by ABPM. The median of the apnoea-hypopnoea index (AHI) was 12.0 (25th-75th percentile 5.0-23.8). Moderate/severe SA (AHI>/=15) was associated with BMI, waist circumference, mean night saturation (SpO(2)), t90, oxygen desaturation index (ODI), ESS (daytime BP only) (p</=0.032), but not ABPM parameters and Mallampati score (p>0.09). A likelihood of moderate/severe SA was enhanced by ODI>14.5 events/h (odds ratio=57.49, 95 % CI=22.79-145.01), t90>6.5 % (8.07, 4.09-15.92), mean night SpO(2)<93.5 % (3.55, 1.92-6.59), BMI>29.05 kg/m(2) (6.22, 3.10-12.49), circum waist>105.5 cm (3.73, 1.57-8.83), but not by any ABPM parameter. In conclusion, a high incidence of SA (72.9 %) was observed in Czech patients with NH. SA severity was associated with body characteristics and oxygenation parameters, but not with ABMP parameters and Mallampati score.

Proguanylin: development, analytical characterization, and clinical testing of a new ELISA

The aim of our work was to develop an assay for the determination of proguanylin in human blood, and investigate its levels in healthy volunteers and donors suffer from hypertension often accompanied by body sodium accumulation and plasma volume expansion. We developed and evaluated the sandwich ELISA method for the quantitative determination of human proguanylin in serum samples. We conducted also the pilot study on individuals with hypertension and oh healthy probands and measured proguanylin serum levels, serum and urine sodium and creatinine levels. In the study on 256 healthy volunteers we demonstrated that women have significantly higher values of proguanylin than men (medians 12.7 vs. 9.6 ng/ml, p < 0.01) and proguanylin values increased with age of individuals (p < 0.01). Futhermore, we tested 17 individuals with hypertension and found that probands with anamnesi of hypertension had higher proguanylin values than healthy individuals from the first study (medians 16.2 vs. 11.3 ng/ml, p < 0.01). Both of groups did not differ in sex or age. Proguanylin values correlated with the systolic blood pressure (r = 0.41, p < 0.01), sodium fraction excretion (r = 0.72, p < 0.01) and serum sodium (r = -0.39, p < 0.01). No significant correlation we found with serum proguanylin and creatinine. In the group of 9 healthy probands we demonstrated the existence of a diurnal rhythm of proguanylin with its maximum in the evening hours (between 6-10 p.m.). The pilot study supports the hypothesis about the role of proguanylin in sodium metabolism and its possible importance for hypertension disorder. Further research is necessary to confirm our findings in individuals with hypertension with different medication in order to assess proguanylin value as a risk predictor of accelerated hypertension, and to classify individuals with hypertension for variuos types of diuretic therapy.

Global gyrokinetic stability of pressure-gradient-driven electromagnetic modes in tokamaks with regions of low shear

Tokamaks with large pressure gradients (alpha(max)) formed in regions of weak magnetic shear are shown to be susceptible to novel, low-n, global, kinetic, electromagnetic modes with a toroidal mode number n in the range 2</=n</=12. For a weakly varying monotonic safety factor profile q with its minimum q(min)>1 on the magnetic axis and alpha(max) near q(min), new, global kinetic infernal modes with a strong mode rotation omega(r) and a finite growth rate gamma<|omega(r)| are found. For equilibria with reverse shear where q(min) is off axis and alpha(max) near q(min), the existence of an unstable low-n global branch of Alfve n ion temperature gradient modes is revealed with an oscillatory gamma as a function of n. The addition of trapped electron dynamics is shown to be further destabilizing.