Blood pressure and progression of chronic kidney disease: Importance of systolic, diastolic, or diurnal variation

Evaluation of renal values during treatment for heartworm disease in 27 client-owned dogs

BACKGROUND

Canine heartworm disease (CHD) caused by Dirofilaria immitis remains a common preventable disease with increasing incidence in some parts of the USA. The treatment guidelines of the American Heartworm Society (AHS) currently recommend monthly macrocyclic lactone administration, 28 days of doxycycline given orally every 12 h and three injections of melarsomine dihydrochloride (1 injection on day 2 of treatment followed 30 days later by 2 injections 24 h apart). Minocycline has also been utilized when doxycycline is unavailable. The systemic effects of CHD, which particularly impact cardiac and renal function, have been described, with infected dogs often experiencing renal damage characterized by an increase in serum concentrations of renal biomarkers. Although the AHS treatment protocol for CHD has been shown to be safe and effective in most cases, the potential for complications remains. No study as of yet has evaluated changes in symmetric dimethylarginine (SDMA), a sensitive marker of renal function, during treatment for CHD. The purpose of the present study was to evaluate renal function in dogs by measuring serum creatinine and SDMA concentrations during the adulticide treatment period.

METHODS

Serum creatinine and SDMA concentrations were measured in 27 client-owned dogs affected by CHD at the following time points: prior to starting doxycycline or minocycline therapy (baseline), during doxycycline or minocycline therapy (interim), at the time of the first dose of melarsomine (first dose), at the time of the second dose of melarsomine (second dose) and at the dog's follow-up visit after treatment, occurring between 1 and 6 months after completion of therapy (post-treatment). Concentrations of creatinine and SDMA were compared between time points using a mixed effects linear model.

RESULTS

Mean SDMA concentrations following the second dose of melarsomine were significantly lower (-1.80 ug/dL, t-test, df = 99.067, t = -2.694, P-Value = 0.00829) than baseline concentrations. There were no other statistically significant differences in the concentration of either biomarker between the baseline and the other time points in CHD dogs undergoing treatment.

CONCLUSIONS

The results suggest that the current AHS protocol may not have a substantial impact on renal function.

Prevalence and associated risk factors of chronic kidney disease: A case study within SIME clinics in Quito, Ecuador 2019-2021

Background

Ecuador has been experiencing an epidemiological transition due to its demographic and lifestyle changes, where non-communicable diseases are the leading cause of death, including chronic kidney disease (CKD). Quito, Ecuador's capital city, is one of the cities burdened by CKD, yet it is unknown the factors that contribute to the rising incidence of this disease. The purpose of this study was to estimate the prevalence of CKD among non-institutionalized adults in Quito between 2019 and 2021, and to examine its associations with various risk factors.

Methods

For the analysis of prevalence, the Kidney Disease: Improving Global Outcomes guidelines were used, where an estimated glomerular filtration rate (eGFR) of < 60 ml/min/1.73 m2 was counted as a presumed case of CKD. The Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation was used to calculate eGFR. Multiple linear regression models were used to determined associations between blood pressure, blood glucose, sex, and zone with eGFR. A t-test of independence was used to determine difference in means between sex and zone and eGFR.

Results

A prevalence of 7.2% was found, in which almost 45% of the participants were classified within stages 2-4 of this disease. The risk factors that were significantly associated with eGFR were systolic blood pressure (β = -0.43, p < 0.001), sex, and zone (p < 0.001).

Conclusions

Overall a high prevalence of CKD was found among adults who visited SIME clinics in Quito. Associations between main risk factors and eGFR were found, yet further research is needed to explore CKD in Ecuador and its main cities.

Risk of Chronic Kidney Disease Associated With Orthostatic Hypotensive Stress: A Community-Based Korean Study

BACKGROUND

The relationship between orthostatic blood pressure (BP) changes and incident chronic kidney disease (CKD) has not been explored in Asian populations.

METHODS

We reviewed the data of 7,039 participants from the Ansung-Ansan cohort study. BP was measured in the supine position and 2 minutes after standing. The change in BP from the supine to upright position was defined as orthostatic BP change. Orthostatic systolic BP (SBP) decline was defined as an orthostatic SBP change of <-2 mm Hg. The primary outcome was the development of CKD, defined as the first event of an estimated glomerular filtration rate <60 ml/min/1.73 m2 at least twice during the follow-up period.

RESULTS

Of 7,039 participants, 949 (13.5 %) developed incident CKD over a mean of 11.9 years. Although orthostatic diastolic BP change was not associated with incident CKD, every 1 mm Hg increase in orthostatic SBP change was associated with a decreased risk of incident CKD (HR, 0.989; 95% CI, 0.982-0.995; P = 0.001). Orthostatic SBP decline was associated with an increased risk of incident CKD (HR, 1.337; 95% CI, 1.163-1.537; P < 0.001). Older age and diabetes were associated with increased odds of orthostatic SBP decline, whereas male sex and high body mass index were associated with decreased odds of orthostatic SBP decline. Subgroup analysis revealed that orthostatic SBP decline was associated with incident CKD only in non-diabetic participants.

CONCLUSIONS

Orthostatic SBP decline was independently associated with an increased risk of future incident CKD, whereas orthostatic DBP decline was not.

An Observational Registry to Assess Urinary Albumin Evolution in Saudi Hypertensive Patients with the Current Treatment Local algorithm: Results of the RATIONAL Study

Introduction

Hypertension causes microalbuminuria, which if left uncontrolled could progress to kidney damage. Antihypertensive treatment primarily aims at controlling blood pressure (BP), but is also shown to control urine albumin excretion. This renoprotective role of antihypertensive medications consists of halting or reverting albuminuria progression.

Patients and Methods

A national Kingdom of Saudi Arabia (KSA), multicenter, observational, longitudinal study (RATIONAL), evaluated the correlation between BP control and microalbuminuria evolution over 1 year. Adult hypertensive patients with kidney damage were enrolled, after giving written consent.

Results

Of 409 patients, 60% had uncontrolled BP at baseline, down to 34% at 12 months. Over 80% of patients were on mono or double antihypertensive therapy, and angiotensin-receptor blockers (ARB) topped the list of medication classes. Albumin–creatinine ratio (ACR) significantly decreased throughout the study, indicating that BP control is paramount to prevent target organ damage. BP change most strongly correlated with ACR change upon triple therapy (ARB + calcium channel blocker + β-blocker). Importantly, 25% (at 6 months) and 38% (at 12 months) of patients reverted back to normoalbuminuria, mostly upon renin-angiotensin system blockers. Around 80% of study patients had also diabetes, a common condition in KSA, which significantly hindered achievement of normoalbuminuria at 12 months.

Conclusion

A modest but solid correlation between BP control and ACR reduction was identified. Results underline proper BP management in KSA and success of antihypertensive treatment in reverting microalbuminuria or delaying its progress. The study duration might be insufficient to reflect conclusively the beneficial effect of longer-term BP control on microalbuminuria evolution.

Predictors of chronic kidney disease in obstructive sleep apnea patients

Introduction

Obstructive sleep apnea (OSA) is a common condition in patients with chronic kidney disease (CKD). It may worsen renal function in CKD patients and is associated with uncontrolled blood pressure. Although OSA is found in up to 80% of CKD patients, there are limited data available on its clinical features in patients with and without CKD.

Objective

This study aimed to identifying the differences in the clinical characteristics of OSA between CKD and non-CKD OSA patients and determine the clinical predictors for CKD in OSA patients.

Methods

This was a retrospective study conducted at Khon Kaen University's Srinagarind Hospital in Thailand between July and December 2018. The inclusion criteria were diagnosis with OSA via polysomnography and having undergone laboratory tests for CKD. Obstructive sleep apnea is diagnosed according to the apnea-hypopnea index (AHI) as experiencing ≥5 events/hour, while CKD diagnosed based on the KDOQI guidelines. Eligible patients were divided into two groups: OSA with CKD and OSA without CKD. Predictors of CKD in OSA patients were analyzed using multivariate logistic regression analysis.

Results

During the study period, there were 178 OSA patients who met the study criteria, 88 (49.44%) of whom were in the OSA with CKD group. Both age and body mass index were comparable between OSA patients with CKD and those without (age: 59 and 57 years, respectively; body mass index: 30 and 29 kg/m², respectively. There were three significant factors that differed between those with and without CKD group including systolic blood pressure (147 vs 135 mmHg), proportion of patients with diabetes (55% vs 34%), and proportion of patients with Mallampati scores of 3-4 (73% vs 39%). There were three independent predictors for OSA in patients with CKD: female sex, high systolic blood pressure, and Mallampati score of 3 or 4, with adjusted odds ratios (95% confidence interval) of 4.624 (1.554, 13.750), 1.060 (1.020, 1.101), and 2.816 (1.356, 5.849), respectively. The Hosmer-Lemeshow chi-square statistic of the predictive model was 6.06 (p 0.640). Systolic blood pressure of more than 130 and 150 mmHg resulted in sensitivity of 84.21% and specificity of 81.40%, respectively.

Conclusions

Female sex, high systolic blood pressure, and Mallampati score of 3-4 were suggestive of OSA with CKD. Obstructive sleep apnea patients with one or more of these predictors may have a high risk of CKD.

Metabolic syndrome does not always play a critical role in decreased GFR

BACKGROUND

There is a paucity of literature available as to the relationship between different levels of each metabolic syndrome (MetS) component and decreased GFR. In the present study, we aimed to demonstrate whether MetS always plays a critical role in decreased GFR.

METHODS

A cross-sectional study was conducted between February 2010 and September 2012, with 75,468 adults enrolled undergoing measurements of blood pressure as well as tests of blood and urine samples. Univariate and multivariable logistic regression analyses were performed to estimate the odds ratio (OR) with 95% confidence intervals (CI), and the chi-square test was used for categorical variables and described as a percentage.

RESULTS

Of the 75,468 participants, 350 (0.5%) subjects met criteria for the decreased GFR, with a mean age of 48.79 ± 13.76 years. After adjustment for age, diastolic blood pressure and high-density lipoprotein were inversely related to decreased estimated glomerular filtration rate (eGFR) in multivariable analyses, with an OR (95% CI) of 0.57 (0.39-0.84) and 0.41 (0.24-0.72), respectively. The prevalence rate of CKD in critical group was 0.73% (154 of 21,127) and 0% (0 of 370) in noncritical group. In analysis stratified by the type of MetS components, the differences in noncritical group and the reference group were not statistically significant (χ(2 )=( )1.349, p > 0.05).

CONCLUSIONS

MetS does not always play a critical role in decreased GFR, with different levels of individual components of MetS exerting idiosyncratic effects in decreased eGFR. In fact, patients with abnormal body mass index, high triglycerides, and elevated fasting plasma glucose would not have impact on decreased GFR.

The kidney and hypertension: causes and treatment

Chronic kidney disease is both a cause and a consequence of hypertension. Extracellular volume expansion is an important, if not the most important, contributing factor to hypertension seen in chronic kidney disease. Beyond volume expansion, chronic kidney disease-related hypertension is without truly defining characteristics. Consequently, the sequencing of antihypertensive medications for the patient with chronic kidney disease and hypertension becomes arbitrary. Prescription practice in such patients should be mindful of the need for multiple drug classes with at least one of them being a diuretic. Blood pressure goals in the patient with chronic kidney disease and hypertension are set at lower levels than those for patients with essential hypertension alone. It remains to be determined to what level blood pressure should be lowered in the patient with chronic kidney disease, however.

Pathologic Basis and Treatment Considerations in Chronic Kidney Disease-Related Hypertension

Chronic kidney disease (CKD) is both a cause and an effect of hypertension and is multifactorial in its origin. Beyond volume expansion, CKD-related hypertension is without defining characteristics of any consistency. Consequently, the order in which antihypertensive medications are given to the CKD patient with hypertension is arbitrary, although prescription practice is for the most part mindful of the need for multiple drug classes with at least one of them being a diuretic. It is not without reason that blood pressure goals in the hypertensive CKD patient are set at lower levels than those for patients with essential hypertension, but it remains to be determined how much the blood pressure should be decreased in the CKD patient.