Blood Pressure, Proteinuria, and Renal Function Decline: Associations in a Large Community-Based Population

Age and estimated glomerular filtration rate in Chinese older adults: a cohort study from 2014 to 2020

Objectives

This study aimed to fill the data gap of the course of renal function decline in old age and explore changes in renal function across different health states with increasing age.

Methods

This observational, retrospective, single-center cohort study included 5,112 Chinese older adults (3,321 men and 1,791 women, range 60-104 years). The individual rate of estimated glomerular filtration rate (eGFR) decline was analyzed using linear mixed-effects model to account for repeated measures over the years.

Results

The median age was 66 years, median BMI was 24.56 kg/m2, and median eGFR was 89.86 mL/min.1.73 m2. For every 1-year increase in age, women's eGFR decreased by 1.06 mL/min/1.73 m2 and men's by 0.91 mL/min/1.73 m2. We observed greater age-related eGFR decline in men and women with high systolic blood pressure (SBP). Men with high triglyceride (TG), high low-density lipoprotein cholesterol (LDL-C), and low high-density lipoprotein cholesterol (HDL-C), had greater age-related eGFR decline. In women, different BMI groups showed significant differences in age-related eGFR decline, with the highest decline in those with obesity. Additionally, participants with normal baseline eGFR had a faster age-related decline than those with low baseline eGFR.

Conclusion

The eGFR declined linearly with age in Chinese older adults, with women exhibiting a slightly faster decline than men. Both men and women should be cautious of SBP. Older adults with normal baseline renal function experienced a faster eGFR decline. Men with high TG, LDL-C, and low HDL-C levels, as well as obese women, should be vigilant in monitoring renal function.

Slope of the estimated glomerular filtration rate and its associated factors among individuals with chronic kidney disease in the general Japanese population

BACKGROUND

To suppress the incidence of end-stage kidney disease, we need to identify chronic kidney disease (CKD) patients with a high risk of rapid decline in the estimated glomerular filtration rate (eGFR). However, the current status of eGFR slope and its associated factors in the Japanese population have not been fully elucidated.

METHODS

Among examinees aged 40-70 years in the 2014 Specific Health Checkup conducted by the National Health Insurance in Kobe, Japan (n = 61,985), we prospectively observed 7291 examinees with CKD stage G3 from 2014 to 2018.

RESULTS

Until 2018, 4221 examinees continued to undergo annual SHCs for a total of five checkups per subject and had available records of all necessary data. The median eGFR change was -0.22 ml/min/1.73 m2/year. Only 9.2% of those subjects showed rapid eGFR decline (faster than -2.0 ml/min/1.73 m2/year). Logistic regression analysis identified diabetes, smoking habits, high urinary protein levels, older age, high systolic blood pressure, and low serum low-density lipoprotein cholesterol levels as independent predictors for rapid eGFR decline. Hemoglobin A1c levels did not contribute to the eGFR slope in CKD stage-G3 subjects with diabetes and proteinuria.

CONCLUSION

Most Japanese CKD stage-G3 subjects had a very slow decline in eGFR. A small proportion of CKD individuals who have a predictive factor of rapid eGFR decline should receive considerable attention from a nephrologist.

Sex-dependent effects of Canagliflozin on kidney protection in mice with combined hypertension-type 1 diabetes

Canagliflozin (CANA) is a sodium-glucose cotransporter 2 (SGLT2) inhibitor with blood glucose lowering effects. CANA also promotes kidney protection in patients with cardiovascular diseases and type 2 diabetes (T2D), as well as in normoglycemic patients with hypertension or heart failure. Clinical studies, although conduct in both sexes, do not report sex-dependent differences in T2DM treated with CANA. However, the impact of CANA in type 1 diabetes, as well in sex-dependent outcomes in such cohort needs further understanding. To analyze the effects of CANA in mice with combined hypertension and type 1 diabetes, diabetes was induced by STZ injection (5 days, 50mg/kg/day) in both male and female 8 weeks old genetic hypertensive mice (Lin), whereas the control (Lin) received 0.1M sodium citrate injections. 8 weeks after STZ. Mice were fed either regular or CANA-infused diet for 4 weeks. 8 weeks after STZ, hyperglycemia was present in both male and female mice. CANA reversed BG increase mice fed regular diet. Male LinSTZ mice had elevated water intake, urine output, urinary albumin to creatinine ratio (ACR), kidney lesion score, and creatinine clearance compared to the Lin control group. Kidney injury was improved in male LinSTZ + CANA group in male mice. Water intake and urine output were not statistically significantly different in female LinSTZ compared to female LinSTZ+ CANA. Moreover, CANA did not improve kidney injury in female mice, showing no effect in creatinine clearance, lesion score and fibrosis when compared to LinSTZ fed regular diet. Here we show that Canagliflozin might exert different kidney protection effects in male compared to female mice with hypertension and type 1 diabetes. Sex-dimorphisms were previously found in the pathophysiology of diabetes induced by STZ. Therefore, we highlight the importance of in-depth investigation on sex-dependent effects of CANA, taking in consideration the unique characteristics of disease progression for each sex.

Parenchymal volume analysis to assess longitudinal functional decline following partial nephrectomy

OBJECTIVE

To identify factors associated with longitudinal ipsilateral functional decline after partial nephrectomy (PN).

PATIENTS AND METHODS

Of 1140 patients managed with PN (2012-2014), 349 (31%) had imaging/serum creatinine levels pre-PN, 1-12 months post-PN (new baseline), and >3 years later necessary for inclusion. Parenchymal-volume analysis was used to determine split renal function. Patients were grouped as having significant renal comorbidity (CohortSRC : diabetes mellitus with insulin-dependence or end-organ damage, refractory hypertension, or severe pre-existing chronic kidney disease) vs not having significant renal comorbidity (CohortNoSRC ) preoperatively. Multivariable regression was used to identify predictors of annual ipsilateral parenchymal atrophy and functional decline relative to new baseline values post-PN, after the kidney had healed.

RESULTS

The median follow-up was 6.3 years with 87/226/36 patients having cold/warm/zero ischaemia. The median cold/warm ischaemia times were 32/22 min. Overall, the median tumour size was 3.0 cm. The preoperative glomerular filtration rate (GFR) and new baseline GFR (NBGFR) were 81 and 71 mL/min/1.73 m2 , respectively. After establishment of the NBGFR, the median loss of global and ipsilateral function was 0.7 and 0.4 mL/min/1.73 m2 /year, respectively, consistent with the natural ageing process. Overall, the median ipsilateral parenchymal atrophy was 1.2 cm3 /year and accounted for a median of 53% of the annual functional decline. Significant renal comorbidity, age, and warm ischaemia were independently associated with ipsilateral parenchymal atrophy (all P < 0.01). Significant renal comorbidity and ipsilateral parenchymal atrophy were independently associated with annual ipsilateral functional decline (both P < 0.01). Annual median ipsilateral parenchymal atrophy and functional decline were both significantly increased for CohortSRC compared to CohortNoSRC (2.8 vs 0.9 cm3 , P < 0.01 and 0.90 vs 0.30 mL/min/1.73 m2 /year, P < 0.01, respectively).

CONCLUSIONS

Longitudinal renal function following PN generally follows the normal ageing process. Significant renal comorbidities, age, warm ischaemia, and ipsilateral parenchymal atrophy were the most important predictors of ipsilateral functional decline following establishment of NBGFR.

Ambulatory blood pressure as risk factor for long-term kidney function decline in the general population: a distributional regression approach

The results of randomized controlled trials are unclear about the long-term effect of blood pressure (BP) on kidney function assessed as the glomerular filtration rate (GFR) in persons without chronic kidney disease or diabetes. The limited duration of follow-up and use of imprecise methods for assessing BP and GFR are important reasons why this issue has not been settled. Since a long-term randomized trial is unlikely, we investigated the association between 24-h ambulatory BP (ABP) and measured GFR in a cohort study with a median follow-up of 11 years. The Renal Iohexol Clearance Survey (RENIS) cohort is a representative sample of persons aged 50 to 62 years without baseline cardiovascular disease, diabetes, or kidney disease from the general population of Tromsø in northern Norway. ABP was measured at baseline, and iohexol clearance at baseline and twice during follow-up. The study population comprised 1589 persons with 4127 GFR measurements. Baseline ABP or office BP components were not associated with the GFR change rate in multivariable adjusted conventional regression models. In generalized additive models for location, scale, and shape (GAMLSS), higher daytime systolic, diastolic, and mean arterial ABP were associated with a slight shift of the central part of the GFR distribution toward lower GFR and with higher probability of GFR < 60 mL/min/1.73 m2 during follow-up (p < 0.05). The use of a distributional regression method and precise methods for measuring exposure and outcome were necessary to detect an unfavorable association between BP and GFR in this study of the general population.

Effects of a High-Protein Diet on Kidney Injury under Conditions of Non-CKD or CKD in Mice

Considering the prevalence of obesity and global aging, the consumption of a high-protein diet (HPD) may be advantageous. However, an HPD aggravates kidney dysfunction in patients with chronic kidney disease (CKD). Moreover, the effects of an HPD on kidney function in healthy individuals are controversial. In this study, we employed a remnant kidney mouse model as a CKD model and aimed to evaluate the effects of an HPD on kidney injury under conditions of non-CKD and CKD. Mice were divided into four groups: a sham surgery (sham) + normal diet (ND) group, a sham + HPD group, a 5/6 nephrectomy (Nx) + ND group and a 5/6 Nx + HPD group. Blood pressure, kidney function and kidney tissue injury were compared after 12 weeks of diet loading among the four groups. The 5/6 Nx groups displayed blood pressure elevation, kidney function decline, glomerular injury and tubular injury compared with the sham groups. Furthermore, an HPD exacerbated glomerular injury only in the 5/6 Nx group; however, an HPD did not cause kidney injury in the sham group. Clinical application of these results suggests that patients with CKD should follow a protein-restricted diet to prevent the exacerbation of kidney injury, while healthy individuals can maintain an HPD without worrying about the adverse effects.

Factors Associated with the Antihypertensive Effect of Esaxerenone and Serum Potassium Elevation: A Pooled Analysis of Seven Phase III Studies

INTRODUCTION

This study investigated factors associated with the antihypertensive effects of esaxerenone and the incidence of serum potassium elevation in patients with hypertension.

METHODS

Using pooled data from seven phase III studies, the study analyzed factors associated with changes in office systolic (SBP) and diastolic (DBP) blood pressure from baseline to 12 weeks, and factors associated with incidence of serum potassium levels ≥ 5.5 mEq/L in esaxerenone-treated patients.

RESULTS

Overall, 1466 and 1472 patients were included in the full analysis and safety analysis sets, respectively. Male sex (4.02/2.40 mmHg), weight ≥ 78.4 kg (4.62/2.09 mmHg), hypertension duration ≥ 10 years (2.66/1.71 mmHg), prior antihypertensive treatment (2.38/1.40 mmHg), plasma aldosterone concentration ≥ 120 pg/mL (1.66/1.17 mmHg), urinary albumin-to-creatinine ratio (UACR) ≥ 300 mg/gCr (8.94/4.85 mmHg) or 30-299 mg/gCr (5.17/4.15 mmHg), and smoking (2.62/1.27 mmHg) were associated with mean changes in SBP and DBP. Fasting blood glucose ≥ 126 mg/dL (- 2.73 mmHg) was associated with the mean change in SBP only, and older age (65-74 years, - 2.12 mmHg; and ≥ 75 years, - 3.06 mmHg) with mean change in DBP only. Factors significantly associated with incidence of serum potassium levels ≥ 5.5 mEq/L were higher baseline serum potassium (≥ 4.5 mEq/L, odds ratio [OR] 6.702); lower estimated glomerular filtration rate (≥ 90 mL/min/1.73 m², OR 0.148; 60-89 mL/min/1.73 m², OR 0.331 vs 30-59 mL/min/1.73 m², respectively); higher UACR (30-299 mg/gCr, OR 7.317); higher DBP (≥ 100 mmHg, OR 3.248); and grade I hypertension (OR 2.168).

CONCLUSION

Esaxerenone is effective in patients with a broad range of backgrounds, though some factors may predict increased benefit. Regarding elevated serum potassium, careful therapeutic management is recommended for patients with higher baseline serum potassium and reduced renal function.

CLINICAL TRIAL REGISTRATION

UMIN000047026.

High fat diet is protective against kidney injury in hypertensive-diabetic mice, but leads to liver injury

Chronic kidney disease (CKD) is a worldwide health burden with increases risk of end-stage renal function if left untreated. CKD induced in the context of metabolic syndrome (MS) increases risks of hypertension, hyperglycemia, excess body fat and dyslipidemia. To test if combining a high-fat diet (HFD) regimen onto the hypertensive/ diabetic phenotype would mimic features of MS induced-CKD in mice, hyperglycemia was induced in genetically hypertensive mice (Lin), followed by HFD regimen. For that, 8-week-old male were subjected to streptozotocin (STZ) intraperitoneal (i.p.) injections (50 mg/kg, 5 days consecutive). LinSTZ were fed a 60% kCal HFD for 8 weeks. Lin mice treated with STZ developed polydipsia, became hypertensive and hyperglycemic. HFD induced weight gain, protected against glomerular hypertrophy, scarring, and albuminuria at endpoint compared to regular diet fed LinSTZ. On the other hand, HFD induced steatosis, liver fibrosis, inflammation, and increase in AST/ALT ratio, characteristics of non-alcoholic liver disease. Taken together, our results show that LinSTZ mice fed a HFD did not lead to a more robust model of MS-induced CKD, protected against kidney injury, but inducing liver damage. More studies are necessary to understand the kidney protective mechanisms of HFD when superimposed with hypertension and type 1 diabetes.

Impact of hypertension and diabetes on the onset of chronic kidney disease in a general Japanese population

Hypertension (HT) and diabetes mellitus (DM) are both major risk factors for chronic kidney disease (CKD); however, few studies have examined the impacts of the combination of HT and DM on CKD development in general populations. We aimed to explore whether HT or DM contributes more to CKD development in a Japanese community. A total of 5823 individuals without a history of CKD who underwent specific health checkups in fiscal year 2013 were monitored until the end of March 2018. Participants were categorized as having neither HT nor DM (none group), either HT or DM, and both (HT + DM). We calculated the hazard ratios (HRs) for developing CKD in each category using Cox proportional hazards models after adjusting for age, dyslipidemia, smoking, and alcohol drinking and with the none group as the reference. We also estimated the population attributable fraction (PAF) for CKD development in populations with either HT or DM or both. During a mean follow-up of 3.0 years, 759 individuals developed CKD, with HRs of 1.56 with a 95% confidence interval (CI) [1.33, 1.83], 1.22 with a 95% CI [0.86, 1.75], and 2.83 with a 95% CI [2.22, 3.63] for the HT only, DM only and HT + DM categories, respectively. Sex-specific analysis showed similar findings. The PAFs for CKD (14.1% and 17.2% for men and women, respectively) were the highest among participants with HT only. We concluded that in this Japanese community, HT contributed more than DM to CKD development; hence, managing hypertension is important to prevent CKD as well as diabetes.

The effect of the Kasuya CKD network on prevention of the progression of chronic kidney disease: successful collaboration of a public health service, primary care physicians and nephrologists-community based cohort study

BACKGROUND

In 2012, we established a CKD network in collaboration with the public health service, primary care physicians, and nephrologists in the Kasuya area. The aim of this study was to clarify if our CKD network was effective in preventing CKD progression.

METHODS

1591 subjects, who had CKD in health checks in 2012 were included in this study. The slope of estimated glomerular filtration rate (eGFR) was compared before and after 2012. Parameters at the first health check visit before 2012, visit in 2012, and the last visit after 2012, were compared. Paired t test, analysis of variance for repeated measurements, and the Friedman test were used for the analysis.

RESULTS

Mean age was 65 years. There were 781 men and 810 women. Mean eGFR was 59 ml/min/1.73 m². The mean slope of eGFR before 2012 was -1.833 ml/min/1.73 m²/year and significantly reduced to - 0.297 after 2012. Low-density lipoprotein cholesterol showed a significant serial lowering. Uric acid was significantly elevated in 2012 compared to the first visit and had decreased by the last. The dipstick urinary protein significantly increased in 2012 compared to the first visit and decreased by the last. The number of current smokers showed a significant reduction over time. On the other hand, systolic blood pressure (SBP) and HbA1c significantly elevated at the last visit.

CONCLUSION

The Kasuya CKD network may be effective in preventing CKD progression.

Twenty-year Follow-up of Patients With Epidemic Glomerulonephritis due to Streptococcus zooepidemicus in Brazil

Introduction

Post-streptococcal glomerulonephritis (PSGN) has a good prognosis in children, but few studies have evaluated the long-term renal outcomes in adults with PSGN.

Methods

In a follow-up study, 47 predominantly adult patients with PSGN due to group C Streptococcus zooepidemicus were reassessed 20 years after an outbreak in Nova Serrana, Brazil. We evaluated clinical characteristics, renal outcomes, and the trajectory of the estimated glomerular filtration rate (eGFR) by the creatinine-based chronic kidney disease-epidemiology collaboration equation from 5 follow-up assessments. Logistic regression and mixed-effects regression were used in the analysis.

Results

After 20 years, the participants’ mean age was 56.6±15.1 years. Thirty-four (72%) patients had hypertension, 21 (44.7%) had eGFR <60 ml/min per 1.73 m², 8 of 43 (18.6%) had urine protein-to-creatinine ratio >150 mg/g, and 25 (53%) had CKD (low eGFR and/or increased proteinuria). Increasing age was associated with CKD (odds ratio: 1.07; 95% confidence interval [CI]: 1.02–1.13; P = 0.011) in multivariate analysis. The mean eGFR decline in the last 11 years of follow-up was −3.2 ml/min per 1.73 m² per year (95% CI: −3.7 to −2.7). Older age at baseline (coefficient −1.05 ml/min per 1.73 m² per year; 95% CI −1.28 to −0.81; P < 0.001), and hypertension 5 years after the outbreak (coefficient −7.78 ml/min/1.73 m²; 95% CI −14.67 to −0.78; P = 0.027) were associated with lower eGFR during the whole study period.

Conclusion

There was a marked worsening of renal function and a high prevalence of CKD and hypertension after 20 years of PSGN outbreak. Long-term follow-up is warranted after PSGN, especially among older patients.

Current antihypertensive treatment and treatment-resistant hypertension in Japanese patients with chronic kidney disease

BACKGROUND

Hypertension is an important prognostic predictor in patients with chronic kidney disease (CKD), and the recommended target blood pressure has been continuously revised. This study aimed to reveal the current antihypertensive practices in Japanese patients with CKD.

METHODS

In the Fukuoka Kidney disease Registry, we extracted 3664 non-dialysis-dependent patients with CKD. Apparent treatment-resistant hypertension (aTRH) was defined as a failure of blood-pressure control treated with three antihypertensive medication classes or a treatment with ≥ 4 classes regardless of blood pressure. The blood-pressure control complied with the target blood pressure recommended by the KDIGO 2012 guideline.

RESULTS

The median age of the patients was 67 years, body mass index (BMI) was 23 kg/m², and estimated glomerular filtration rate (eGFR) was 40 mL/min/1.73 m². The number of patients with unachieved blood-pressure control was 1933, of whom 26% received ≥ 3 classes of antihypertensive medications. The first choice of medication was renin-angiotensin system inhibitors, followed by calcium-channel blockers. The rate of thiazide use was low in all CKD stages (3-11%). The prevalence of aTRH was 16%, which was significantly associated with BMI (odds ratio [95% confidence interval] per 1-standard deviation change, 1.38 [1.25-1.53]), decreased eGFR (1.87 [1.57-2.23]), as well as age, diabetes mellitus, and chronic heart disease.

CONCLUSIONS

Renal dysfunction and obesity are important risk factors of aTRH. Even under nephrologist care, most patients were treated with insufficient antihypertensive medications. It is important to prescribe sufficient classes of antihypertensive medications, including diuretics, and to improve patients' lifestyle habits.

Association of blood pressure and long-term change with chronic kidney disease risk among Chinese adults with different glucose metabolism according to the 2017 ACC/AHA guidelines

Whether the definition of hypertension according to 2017 AHA/ACC guidelines and blood pressure (BP) changes was related to the increased risk of chronic kidney disease (CKD) remained debated. This prospective cohort study aimed to investigate the association of BP and long‐term BP change with CKD risk with different glucose metabolism according to the new hypertension guidelines. This study examined 12 951 participants and 11 183 participants derived from the older people cohort study, respectively. Participants were divided into three groups based on blood glucose and the risks were assessmented by the logistic regression model. During a 10 years of follow‐up period, 2727 individuals developed CKD (21.1%). Compared with those with BP < 130/80 mmHg, individuals with increased BP levels had significantly increased risk of incident CKD. Participants with BP of 130–139/80–89 or ≥140/90 mmHg had 1.51‐ and 1.89‐fold incident risk of CKD in patients with diabetes mellitus (DM). Compared with individuals with stable BP (−5 to 5 mmHg), the risk of CKD was reduced when BP decreased by 5 mmHg or more and increased when BP increased ≥5 mmHg among normoglycemia and prediabetes participants. Similar results were observed for rapid estimated glomerular filtration rate (eGFR) decline. In conclusion, the BP of 130–139/80–89 mmHg combined with prediabetes or DM had an increased risk of incident CKD and rapid eGFR decline in older people. Long‐term changes of BP by more than 5 mmHg among normoglycemia or prediabetes were associated with the risk of incident CKD and rapid eGFR decline.

Long-term chronological changes in renal function and functional renal volume after nephron-sparing surgery: A prospective observational study

OBJECTIVES

To investigate long-term chronological changes in functional renal volume and renal function after nephron-sparing surgery, and factors that contribute to the progression of postoperative chronic kidney disease.

METHODS

A total of 80 patients who underwent nephron-sparing surgery were enrolled in this prospective observational study. The renal function deterioration group was defined as patients whose estimated glomerular filtration rate at 5 postoperative years decreased by ≥20% relative to that before surgery.

RESULTS

The predicted estimated glomerular filtration rate, calculated based on the functional renal volume at 5 postoperative years, was strongly correlated with the postoperative estimated glomerular filtration rate (Spearman's ρ = 0.89, P < 0.001). The rate of new-onset stage IIIb chronic kidney disease was significantly higher in the renal function deterioration group than in the stable renal function group (P < 0.001). Multivariate analysis identified proteinuria (P = 0.017), small preoperative total functional renal volume (≤250 mL, P = 0.046) and large tumor volume (≥4.5 mL, P = 0.036) as independent factors associated with renal function deterioration.

CONCLUSIONS

Our findings show that the functional renal volume is significantly associated with renal function, even in the long-term postoperative period. Additionally, for patients with preoperative proteinuria, large tumor volume and small total preoperative functional renal volume, both oncological follow ups and medical interventions, including prevention of lifestyle-related diseases, might prevent the progression of chronic kidney disease.

Distribution of estimated glomerular filtration rate and determinants of its age dependent loss in a German population-based study

Glomerular filtration rate (GFR) declines with age by approx. 1 ml/min/m² per year beginning in the third decade of life. At 70 years of age > 40 ml/min/m² of GFR will be lost. Thus, factors affecting loss of GFR have significant public health implications. Furthermore, the definition of chronic kidney disease based on GFR may not be appropriate for the elderly. We analyzed factors affecting absolute and relative change of eGFR over a 5 year period in 12,381 participants of the Gutenberg Health Study. We estimated GFR at baseline and after 5 years of follow-up by two different equations. Association with the decline of estimated GFR (eGFR) was assessed by multivariable regression analysis. We confirmed a median loss of eGFR per year of approx. 1 ml/min/m². Aside from albuminuria systolic blood pressure was most strongly associated with faster decline of eGFR followed by echocardiographic evidence of left ventricular diastolic dysfunction and reduced ejection fraction. White blood cell count showed a moderate association with eGFR loss. Diastolic blood pressure, serum uric acid and serum albumin were associated with slower GFR decline in multivariable analysis. Sensitivity analysis with exclusion of individuals taking diuretics, antihypertensive, antidiabetic, or lipid lowering drugs confirmed these associations.

Impact of Chronic Kidney Disease on Aortic Disease-related Mortality: A Four-year Community-Based Cohort Study

Objective Despite advances in medicine, aortic diseases (ADs), such as aneurysm rupture and aortic dissection, remain fatal and carry extremely high mortality rates. Due to its low frequency, the risk of developing AD has not yet been fully elucidated. Chronic kidney disease (CKD) is an established risk factor for cardiovascular disease and mortality. The aim of the present study was to examine whether or not CKD is a risk for AD-related mortality in the general population. Methods We used a nationwide database of 554,442 subjects (40-75 years old) who participated in the annual "Specific Health Check and Guidance in Japan" checkup between 2008 and 2013. Results There were 131 aortic aneurysm and dissection deaths during the follow-up period of 2,123,512 person-years. A Kaplan-Meier analysis revealed that subjects with CKD had a higher rate of AD-related deaths than those without it. A multivariate Cox proportional hazard regression analysis demonstrated that CKD was an independent risk factor for AD-related death in the general population after adjusting for cardiovascular risk factors. The addition of CKD to cardiovascular risk factors significantly improved the C, net reclassification, and integrated discrimination indexes. Conclusion CKD is an additional risk for AD-related death, suggesting that CKD may be a target for the prevention and early identification of subjects at high risk for AD-related death in the general population.

Antihypertensive effects and safety of esaxerenone in patients with moderate kidney dysfunction

Renin–angiotensin system inhibitors are recommended for treating hypertension with chronic kidney disease. The addition of a mineralocorticoid receptor blocker may be one option to achieve target blood pressure. We investigated the efficacy and safety of esaxerenone, a mineralocorticoid receptor blocker, in Japanese hypertensive patients with moderate kidney dysfunction. Two multicenter, open-label, nonrandomized dose escalation studies were conducted to investigate esaxerenone monotherapy and add-on therapy to renin–angiotensin system inhibitor treatment. Esaxerenone therapy was initiated at 1.25 mg/day and titrated to 2.5 and then 5 mg/day for a treatment duration of 12 weeks. Primary endpoints were changes from baseline in sitting systolic and diastolic blood pressure. Safety, pharmacokinetics, and urinary albumin-to-creatinine ratios were also assessed. Thirty-three patients received monotherapy, and 58 received add-on therapy; the mean baseline estimated glomerular filtration rates were 51.9 and 50.9 mL/min/1.73 m², respectively. The esaxerenone dosage was increased to ≥2.5 mg/day in 100% (n = 33) and 93.1% (n = 54) of patients receiving monotherapy and add-on therapy, respectively. Reductions in sitting blood pressure from baseline to the end of treatment were similar (monotherapy: −18.5/−8.8 mmHg; add-on therapy: −17.8/−8.1 mmHg; both P < 0.001). The antihypertensive effects of esaxerenone were consistent across patient subgroups. A serum K⁺ level ≥5.5 mEq/L was observed in seven patients (12.1%) receiving add-on therapy but in none receiving monotherapy. All increases in serum K⁺ levels were transient, and no patient met predefined serum K⁺ level criteria for dose reduction or therapy discontinuation. No patient discontinued treatment owing to kidney function decline. Esaxerenone was effective and well tolerated in hypertensive patients with moderate kidney dysfunction.

Impact of pharmacist intervention for blood pressure control in patients with chronic kidney disease: A meta-analysis of randomized clinical trials

WHAT IS KNOWN AND OBJECTIVE

Hypertension (HTN) and chronic kidney disease (CKD) are recognized as silent killers because they are asymptomatic conditions that contribute to the burden of multiple comorbidities. The achievement of a blood pressure (BP) goal can dramatically reduce the risks of CKD. In this study, we aimed to assess the effectiveness of pharmacist intervention on BP control in patients with CKD and evaluate the usefulness of home-based BP telemonitoring.

METHODS

The terms "chronic kidney disease," "pharmacist," "BP" and "randomized controlled trial (RCT)" were used five databases to search for information regarding pharmacist intervention on BP control in patients with CKD. The inclusion criteria were as follows: (a) studies for adult patients with uncontrolled HTN and (b) studies with adequate data for meta-analysis. The primary outcome was an evaluation of achievement of BP goal in patients with CKD. The secondary outcome was usefulness of home-based BP telemonitoring by pharmacists in patients with CKD.

RESULTS AND DISCUSSION

Six RCTs were identified and included in the meta-analysis with a total of 2573 patients (mean age 66.0 years and 63.9% male). Pharmacist interventions resulted in significantly better BP control vs usual care (OR = 1.53, 95% CI = 1.15-2.04, P < .01). Pharmacist interventions using home-based BP telemonitoring were significantly superior to control/usual care (OR = 2.03, 95% CI = 1.49-2.77, P < .01), whereas pharmacist interventions without home-based BP telemonitoring did not significantly improve BP control compared to that with control/usual care (OR = 1.30, 95% CI = 0.97-1.75, P = .08). Home-based BP telemonitoring supported team-based care for HTN in these studies. In addition, patient self-monitoring with telemedicine devices might enhance patients' abilities to manage their condition by pharmacist instruction.

WHAT IS NEW AND CONCLUSION

The findings of this meta-analysis showed that pharmacist interventions with home-based BP telemonitoring improve BP control among adult patients with CKD.

Blood Pressure is Associated with Rapid Kidney Function Decline in a Very Elderly Hypertensive Chinese Population

Purpose

In prior analyses, blood pressure (BP) was related to rapid kidney function decline (RKFD). However, studies of this relationship in populations of advanced age are lacking. In the present study, we therefore examined the relationship between BP and RKFD in a population of 284 hypertensive Chinese individuals over the age of 80.

Patients and Methods

All study participants were diagnosed with hypertension (systolic BP [SBP] 160–200 mmHg; diastolic BP [DBP] <110 mmHg). RKFD was defined based upon a decline in estimated glomerular filtration rate (eGFR) >5mL/min per 1.73 m² per year during follow-up. The Cox regression models (competing risk models) were used for calculating hazard ratios (HRs) to examine the relationship between SBP, DBP, pulse pressure (PP) and RKFD.

Results

Over a 3.3-year median follow-up period, 68 study participants (23.9%) were diagnosed with RKFD, while 35 (12.3%) died. After adjusting for confounding variables, we determined that each 10 mmHg rise in SBP and PP was associated with a 34% and 110% increase, respectively, in RKFD risk (adjusted HR: 1.34, 95% confidence interval [CI]: 1.05–1.71 for SBP, p=0.02; HR: 2.10, 95% CI: 0.87–5.08 for PP, p=0.10). In addition, we determined that each 10 mmHg increase in DBP was linked to a 10% reduction in RKFD risk (adjusted HR: 0.90, 95% CI: 0.70–1.14, p=0.37).

Conclusion

Our results indicate that SBP, but not DBP or PP, is positively correlated with RKFD risk in a very elderly hypertensive Chinese population.

Blood Pressure and Chronic Kidney Disease Stratified by Gender and the Use of Antihypertensive Drugs

Background

The present study assessed the association between blood pressure (BP) and the risk of chronic kidney disease (CKD) according to gender and the use of antihypertensive drugs using data from a large‐scale health checkup.

Methods and Results

We conducted a retrospective cohort study using the JMDC database, which contains annual health checkup data of Japanese employees and their dependents aged <75 years. We included 154 692 participants (men, 69.68%; mean age, 44.74 years) without CKD. CKD was indicated by an estimated glomerular filtration rate <60 mL/min per 1.73 m² or the presence of proteinuria. During the mean follow‐up period of 4.78 years, new‐onset CKD occurred in 14 888 participants. When the normal BP group (systolic/diastolic BP <120/<80 mm Hg) without treatment was used as a reference, the hazard ratios of the high BP (130–139/80–89 mm Hg) and grade 1 (140–159/90–99 mm Hg) and grade 2 or 3 hypertension (≥160/≥100 mm Hg) groups were 1.11 (95% CI, 1.06–1.17), 1.36 (95% CI, 1.28–1.45), and 1.76 (95% CI, 1.56–1.99) for untreated men, respectively. However, in treated men, even normal BP was associated with a 1.5‐fold higher risk of CKD. The association between BP and the risk of CKD was weaker in untreated women than in untreated men. The risk of CKD in treated women with normal BP was similar to that of untreated women with normal BP.

Conclusions

Gender differences were found in the association between BP and CKD risk. Kidney function in treated individuals should be followed carefully, especially in men.

Uric acid is independent and inversely associated to glomerular filtration rate in young adult Brazilian individuals

BACKGROUND AND AIMS

Uric acid, the end-product of human purine metabolism, is associated with hypertension, diabetes and obesity. It has also been independently associated with the onset of chronic kidney disease in several populations. In this study, the association between serum uric acid (SUA) level and estimated glomerular filtration rate (eGFR) was investigated in healthy individuals belonging to two Brazilian birth cohorts.

METHODS AND RESULTS

Data from 3541 to 3482 individuals, aged 30 and 22-years old, respectively, was included. eGFR was calculated using Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation based on creatinine measurement. Regression analyses were sex-stratified due to interaction between SUA and sex (p < 0.001) and adjusted for perinatal, cardiometabolic and behavioral variables. We observed an inverse association between eGFR and SUA even after adjustment. In the highest tertile (3rd) of SUA, the eGFR coefficients at 30-years were-0.21 (95%CI -0.24;-0.18) for men and -0.20 (95%CI -0.23; -0.17) for women; at 22-years, were -0.09 (95%CI -0.12;-0.05) for men and -0.13 (95%CI -0.15; -0.10) for women. Higher differences among exponential means (95% CI) of eGFR between the 1st and the 3rd tertile of SUA were seen in older participants, being more pronounced in men. At 22-years, the highest difference was found in women.

CONCLUSIONS

In young healthy individuals from a low-middle income country, SUA level was inversely associated with eGFR. Gender-related differences in eGFR according tertiles of SUA were higher in men at 30-years and in women at 22-years.

Practical Strategy for Treating Chronic Kidney Disease (CKD)-Associated with Hypertension

When renal function declines, blood pressure rises, which in turn causes the kidneys to deteriorate. In order to stop this vicious cycle, it is necessary to lower the blood pressure to a "moderate" level in patients who have chronic kidney disease (CKD)-associated hypertension. Such optimization is problematic, since tight control of blood pressure might worsen the prognosis in elderly patients with CKD, especially those with advanced arteriosclerosis. Although renin-angiotensin system (RAS) inhibitors, angiotensinogen converting enzyme (ACE) inhibitors and angiotensin II receptor blockers (ARBs) are first-line drugs for hypertensive patients with diabetes, they should be used with caution depending on the patients' conditions. Recently, there has been a focus on the preventive effects of sodium-glucose cotransporter 2 (SGLT2) inhibitors, anti-diabetic drugs that have been shown to have an impact, on heart and kidney complications. SGLT2 inhibitors increase the amount of sodium chloride delivered to the macular densa of the distal tubules and correct glomerular hyperfiltration by contraction of afferent arterioles via the tubule-glomerular feedback system. It might be one of the reasons why SGLT2 inhibitors show the renal- and cardio-protective effects; however, the mechanism behind their function remains to be elucidated.

Recent advances in the management of secondary hypertension: chronic kidney disease

Hypertension in chronic kidney disease (CKD) is the most commonly observed comorbidity and is a risk factor for end-stage renal disease (ESRD) as well as cardiovascular disease (CVD) and mortality. Therefore, suitable blood pressure (BP) control in CKD patients is very important in preventing both CVD and ESRD. We herein describe the recommendations of target BP and the pharmacological drug options from the evidence-based clinical practice guidelines for CKD in 2018 by the Japanese Society of Nephrology (JSN CKD 2018) and recent advances in the management of hypertension in CKD, including sodium-glucose cotransporter (SGLT) 2 inhibitors, mineralocorticoid receptor blockers, and renal denervation. In particular, SGLT2 inhibitors are a new class of "antihypertensive drugs" that have a homeostatic mechanism that regulates body fluid volume in addition to diuretic action, which may be closely associated with their cardiorenal protective properties.

Associations between urinary cadmium levels, blood pressure, and hypertension: the ESTEBAN survey

Cadmium is inconsistently associated with blood pressure (BP) and hypertension. Our study focuses to understand the association between urinary cadmium levels, blood pressure, and hypertension in a French representative sample. Our study included 2015 subjects from the ESTEBAN survey (2014-2015) with measured urinary cadmium. Associations between natural logarithm-transformed cadmium levels and BP (systolic (SBP) and diastolic blood pressure (DBP)) were performed by adjusted linear regression models. Associations between cadmium and hypertension were performed by adjusted logistic regression models. Models were stratified by gender, smoking habits, body mass index (BMI), and kidney function categories. Men present higher SBP (131.7 vs. 121.5 mmHg, p < 0.0001) and DBP (78.9 vs. 74.7 mmHg, p < 0.0001) in comparison to women. Creatinine-adjusted urinary cadmium levels (0.48 vs. 0.39 μg/L, p < 0.0001) were higher in hypertensive subjects. Nevertheless, no difference was observed after adjustment for age, gender, and smoking habits. No correlation between urinary cadmium, BP, and hypertension was observed in overall population. Stratified models showed inverse correlations between urinary cadmium and hypertension among obese (OR = 0.39, 95% CI [0.21-0.57], p = 0.0009), chronic kidney function (OR = 0.68 95%CI [0.75-0.97], p = 0.003), and current smokers (OR = 0.78, 95% CI [0.64-0.92], p = 0.04). A correlation between urinary cadmium levels, BP, and hypertension is observed in subpopulations. Nevertheless, directions and significance of these associations differs by gender, BMI, smoking, and kidney function categories.

Markers and risk factors for chronic kidney disease in sub-Saharan Africans: baseline levels and 12-month trajectories in newly referred patients in Cameroon

Background

Little is known about the changes in disease makers and risk factors in patients with chronic kidney disease (CKD) under nephrological care in Africa. This study aimed to evaluate the baseline level of markers of CKD and their 12-month time-trend in newly referred patients in a tertiary hospital in Cameroon.

Methods

This was a retrospective cohort study including 420 patients referred for CKD between 2006 and 2012 to the nephrology unit of the Douala General Hospital in the littoral region of Cameroon. Their disease and risk profile was assessed at baseline and every 3 months for 1 year. Estimated glomerular filtration rate (eGFR) was based on MDRD and Schwartz equations. CKD was diagnosed in the presence of eGFR< 60 ml/min/1.73 m² and/or proteinuria> 1+ and/or abnormal renal ultrasound persisting for ≥3 months. Data analysis used mixed linear regressions.

Results

Of the 420 patients included, 66.9% were men and mean age was 53.8 (15.1) years. At referral, 37.5% of the participants were at CKD Stage 3, 30.8% at stage 4 and 26.8% at stage 5. There was 168 (40%) diabetic and 319 (75.9%) hypertensive patients. After some improvement during the first 3 months, eGFR steadily decreased during the first year of follow-up, and this pattern was robust to adjustment for many confounders. Systolic and diastolic blood pressure levels significantly fluctuated during the first twelve months of follow-up. Changes in the levels of other risk factors and markers of disease severity over time were either borderline or non-significant.

Conclusion

Patients with CKD in African settings are referred to the nephrologist at advanced stages. This likely translates into a less beneficial effects of specialised care on the course of the disease.

Renal Effects of Angiotensin-Converting Enzyme Inhibitors and Angiotensin Receptor Blockers in Patients with Liver Cirrhosis: A Nationwide Cohort Study

Background

The use of angiotensin-converting enzyme inhibitors (ACEis) and angiotensin receptor blockers (ARBs) carries a risk of renal function deterioration in cirrhotic patients with ascites. However, whether the long-term use of ACEis/ARBs is safe in cirrhotic patients without ascites remains unknown.

Methods

In this nationwide cohort study, we identified 311,361 newly diagnosed cirrhotic patients between January 1997 and December 2013. To avoid indication and immortal time biases, patients receiving regular ACEi/ARB therapy, defined as the ACEi/ARB cohort, were matched to patients receiving regular calcium channel blockers (CCBs), defined as the CCB cohort, at a ratio of 1 : 1 by age, sex, and propensity scores for comorbidities and medications (2,188 patients in each cohort). Cumulative incidence rates and multivariate analyses of end-stage renal disease (ESRD) risk were adjusted for competing mortality.

Results

The 10-year cumulative incidence rates of ESRD were 2.32% (95% confidence interval [CI]: 1.45–3.20) in the ACEi/ARB cohort and 1.70% (95% CI: 1.03–2.36) in the CCB cohort (P = 0.610). In multivariate analyses, ACEi/ARB use was not associated with a higher risk of ESRD in cirrhotic patients (hazard ratio [HR] = 1.15; 95% CI: 0.69–1.94, P = 0.591). In the sensitivity test, the 10-year cumulative incidence rates of ESRD in cirrhotic patients with ascites were 6.50% (95% CI: 0.54–12.46) and 1.24% (95% CI: 0.00–2.71) in ACEi/ARB and CCB cohorts, respectively (P = 0.090).

Conclusions

Long-term ACEi/ARB use was not associated with a higher risk of ESRD in cirrhotic patients. However, the risk of ESRD tended to increase in cirrhotic patients with ascites.

Relationship of reduced glomerular filtration rate with alterations in plasma free amino acids and uric acid evaluated in healthy control and hypertensive subjects

The potential association between altered levels of plasma free amino acids (PFAAs) and uric acid (UA) with estimated glomerular filtration rate (eGFR) remains unknown among patients with hypertension. A total of 2804 healthy controls and 2455 hypertensive patients were included in the current analysis. eGFR was defined as reduced when it was <60 ml/min/1.73 m². The associations between reduced eGFR and individual PFAAs and UA in the healthy control and hypertension groups were explored by logistic regression analyses adjusted for potential confounding variables. Results show that UA had a significant positive association with reduced eGFR in both healthy control and hypertension groups (P < 0.001). Among the PFAAs, citrulline, glycine and phenylalanine showed significant positive associations with reduced eGFR in both healthy control (P < 0.01 to 0.001) and hypertension (P < 0.001) groups. Moreover, alanine, asparagine and methionine achieved significant positive associations with reduced eGFR only in the hypertension group (P < 0.01 to 0.001). Conversely, serine showed significant inverse associations with reduced eGFR in the hypertension group only (P < 0.001). Our findings provide first evidence for a strong relationship between distinct patterns of PFAAs and elevated UA with reduced eGFR in hypertension. The findings may appear useful in developing effective strategies for the prevention or early detection and treatment of declined kidney function in hypertension.

Usefulness of the blood pressure classification in the new 2017 ACC/AHA hypertension guidelines for the prediction of new-onset chronic kidney disease

The aim of this study was to determine whether the blood pressure (BP) classification recommended in the 2017 American College of Cardiology (ACC)/American Heart Association (AHA) hypertension guidelines is useful for the prediction of chronic kidney disease (CKD) in adults. We conducted a retrospective cohort study using annual health check data in Iki City, Nagasaki, Japan. A total of 3269 adults without CKD, who were not on BP-lowering medication, were included in the present analysis. BP was classified as: normal (systolic BP (SBP) <120 mmHg and diastolic BP (DBP) <80 mmHg), elevated BP (120 ≤ SBP < 130 and/or DBP < 80), stage 1 hypertension (130 ≤ SBP < 140 and/or 80 ≤ DBP < 90), and stage 2 hypertension (SBP ≥ 140 mmHg and/or DBP ≥ 90 mmHg). The primary outcome of the study was new-onset CKD. The effects of BP on the development of CKD were evaluated using Cox's proportional hazards modelling. During a mean follow-up of 4.8 years, 472 (14.4%) participants developed CKD. The incidence (per 1000 person-years) of new-onset CKD was higher in individuals with elevated BP. After adjustment for other risk factors, there were significant associations between elevated BP and new-onset CKD: hazard ratio 1.11 (95% confidence interval 0.87-1.42) in elevated BP, 1.25 (1.01-1.54) in stage 1 hypertension, and 1.45 (1.18-1.79) in stage 2 hypertension, compared with the reference group with normal BP (P < 0.001 for trend). Thus, the findings of this study confirm the definition of hypertension (≥130/80 mmHg) recommended by the 2017 ACC/AHA guidelines for the management of hypertension to be useful for the prediction of new-onset CKD.

Long-term kidney function, proteinuria, and associated risks among HIV-infected and uninfected men

BACKGROUND

Factors affecting kidney function and proteinuria among HIV-positive (HIV+) and HIV-negative (HIV-) persons need better characterization.

METHODS

We evaluated estimated glomerular filtration rate (eGFR, ml/min per 1.73 m) changes, proteinuria prevalence (a urine protein-to-creatinine ratio of ≥0.2 at two consecutive visits) and associated factors among HIV+ and HIV- men.

RESULTS

There were 917 HIV+ men receiving HAART, 159 HIV+ men not receiving HAART, and 1305 HIV- men seen from October 2003 to September 2014. Median annual eGFR change was -0.5, -0.8% for HIV+ and -0.3% for HIV- men (P < 0.001). Factors significantly (P < 0.05) associated with more than 3% annual eGFR decline were HAART receipt (but no specific antiretroviral drug), age more than 50, hypertension, diabetes, current smoking. Proteinuria existed in 14.9% of visit-pairs among HAART recipients, 5.8% among non-HAART recipients, and 1.9% among HIV- men, and was associated with subsequent annual more than 3% eGFR decline (odds ratio 1.80, P < 0.001). Proteinuria-associated factors also included HAART use (vs. HIV-), age at least 50 (vs. <40), diabetes, hypertension, current smoking, hepatitis C virus-infection (all P < 0.05) and, among HIV+ men, lower CD4 cell count, didanosine, saquinavir, or nelfinavir use (all P < 0.05). After adjusting for proteinuria, among HAART users, having a detectable HIV RNA, cumulative use of tenofovir disoproxil fumarate, emtricitabine, ritonavir, atazanavir, any protease inhibitor, or fluconazole were associated with more than 3% annual eGFR decline.

CONCLUSION

Longitudinal kidney function decline was associated with HAART use but no individual antiretroviral drug, and traditional kidney disease risks. Proteinuria was nearly seven times more common in HAART-treated men than HIV- men, reflected recent eGFR decline and predicted subsequent eGFR decline.

Urinary type IV collagen excretion is involved in the decline in estimated glomerular filtration rate in the Japanese general population without diabetes: A 5-year observational study

Urinary type IV collagen (U-Col4) and albumin excretion is evaluated to monitor the development of diabetic kidney disease. However, U-Col4 excretion in the general population without diabetes has not yet been fully elucidated. In this study, 1067 participants without diabetes and with urinary albumin-creatinine ratio <300 mg/gCr (normo- or microalbuminuria) who underwent an annual health examination in 2004 were enrolled and observed for 5 years. They were divided according to the amount of U-Col4 or urinary albumin excreted. The decline in estimated glomerular filtration rate (eGFR) was calculated. In participants with eGFR ≥80 mL/min, abnormal U-Col4 excretion was indicated as a significant independent risk factor for 10% eGFR change per year, which is one of the prognostic factors for the development of end-stage kidney disease. Moreover, in contrast to urinary albumin excretion, U-Col4 excretion was not related to age or kidney function, suggesting that some individuals with abnormal U-Col4 excretion can have an independent hidden risk for the development of kidney dysfunction. In conclusion, it is important to measure U-Col4 excretion in the general population without diabetes to determine changes in renal features in every individual and help detect future complications such as diabetic kidney disease. If U-Col4 excretion is abnormal, kidney manifestation should be carefully followed up, even if the kidney function and urinalysis findings are normal.

Annual deterioration of renal function in hypertensive patients with and without diabetes

Background

Chronic kidney disease (CKD) complicates hypertension and diabetes. Knowledge of the deterioration rate of CKD may anticipate adjustment of therapies with renal elimination. This study evaluates the rate of annual deterioration of renal function in hypertensive patients either with type 2 diabetes (DM2) or without it (non-DM) followed for 5 years and relates it with blood pressure (BP) and glycemic control.

Materials and methods

Out of a total of 1924 patients, 1023 patients (594 non-DM and 429 DM2, 53% female, aged 62.1±10.2 years) were evaluated over 5 years for the annual evolution of renal function (estimated glomerular filtration rate [eGFR], Modification of Diet in Renal Disease) ambulatory 24-hour blood pressure and metabolic parameters, corresponding to the analysis of 2378 patient-years.

Results

DM2 and non-DM did not differ for age, mean 24-hour BP levels, nighttime BP, albuminuria, and body mass index. DM2 versus non-DM showed a higher (p<0.02) prevalence of stage 3 CKD (24.0% vs 18.0%, eGFR 30–59), stage 4 (5.4% vs 2.7%, eGFR 15–29), and stage 5 (0.8% vs 0.5%, eGFR <15). Average annual decline of eGFR was 3.3±8.2 in DM2 versus 2.4±7.7 in non-DM (p=0.12, nonsignificant). Annual changes of eGFR and of albuminuria correlated (r=0.578, p<0.001). In multivariate analysis, age, nighttime BP, double inhibition of renin angiotensin system, albuminuria, and HbA1c >8.0% in DM2 predicted the decline in eGFR. On average, 16.2% of DM2 and 13.1% of non-DM moved each year toward a more severe stage of CKD. For initial eGFR <90 mL/min/1.73 m², 26.4% of DM2 and 18.1% of non-DM patients showed a reduction per year >10% from the previous eGFR value (p=0.042).

Conclusion

Progressive deterioration of renal function each year is frequent in hypertensive diabetic and non-diabetic patients. Beyond aging, this is particularly dependent on BP control particularly at nighttime, on drug therapy, and on highly abnormal glucose control.

Longitudinal change in estimated GFR among CKD patients: A 10-year follow-up study of an integrated kidney disease care program in Taiwan

BACKGROUND

This study examined the progression of chronic kidney disease (CKD) by using average annual decline in estimated GFR (eGFR) and its risk factors in a 10-year follow-up CKD cohort.

METHODS

A prospective, observational cohort study, 4600 individuals fulfilled the definition of CKD, with or without proteinuria, were followed for 10 years. The eGFR was estimated by the MDRD equation. Linear regression was used to estimate participants' annual decline rate in eGFR. We defined subjects with annual eGFR decline rate <1 ml/min/1.73 m2 as non-progression and the decline rate over 3 ml/min/1.73 m2 as rapid progression.

RESULTS

During the follow-up period, 2870 (62.4%) individuals had annual eGFR decline rate greater than 1 ml/min/1.73 m2. The eGFR decline rate was slower in individuals with CKD diagnosed over the age of 60 years than those with onset at a younger age. Comparing to subjects with decline rate <1 ml/min/1.73 m2/year, the odds ratio (OR) of developing rapid CKD progression for diabetes, proteinuria and late onset of CKD was 1.72 (95% CI: 1.48-2.00), 1.89(1.63-2.20) and 0.68 (0.56-0.81), respectively. When the model was adjusted for the latest CKD stage, comparing to those with CKD stage 1, patients with stage 4 and stage 5 have significantly higher risks for rapid progression (OR, 5.17 (2.60-10.25), 19.83 (10.05-39.10), respectively). However, such risk was not observed among patients with the latest CKD stage 2 and 3. The risk for incident ESRD was 17% higher for each 1 ml/min/1.73 m2 increasing in annual decline rate.

CONCLUSIONS

Not everyone with CKD develops ESRD after a 10-year follow-up. Absolute annual eGFR decline rate can help clinicians to better predict the progression of CKD. Individuals with renal function decline rate over 3 ml/min/1.73 m2/year require intensive CKD care.

Blood pressure and age-related GFR decline in the general population

BACKGROUND

Hypertension is one of the most important causes of end-stage renal disease, but it is unclear whether elevated blood pressure (BP) also accelerates the gradual decline in the glomerular filtration rate (GFR) seen in the general population with increasing age. The reason may be that most studies have considered only baseline BP and not the effects of changes in BP, antihypertensive treatment and other determinants of GFR during follow-up. Additionally, the use of GFR estimated from creatinine or cystatin C instead of measurements of GFR may have biased the results because of influence from non-GFR related confounders. We studied the relationship between BP and GFR decline using time-varying variables in a cohort representative of the general population using measurements of GFR as iohexol clearance.

METHODS

We included 1594 subjects aged 50 to 62 years without baseline diabetes, kidney-, or cardiovascular disease in the Renal Iohexol-clearance Survey in Tromsø 6 (RENIS-T6). GFR, BP, antihypertensive medication and all adjustment variables were ascertained at baseline, and at follow-up after a median observation time of 5.6 years in 1299 persons (81%). The relationship between GFR decline and BP was analyzed in linear mixed models.

RESULTS

The mean (standard deviation) GFR decline rate was 0.95 (2.23) mL/min/year. The percentage of persons with hypertension (systolic BP ≥ 140 mmHg, diastolic BP ≥ 90 mmHg or antihypertensive medication) increased from 42 to 52% between baseline and follow-up. In multivariable adjusted linear mixed models using time-varying independent variables measured at baseline and follow-up, higher systolic and diastolic BP were associated with slower GFR decline rates by 0.10 and 0.20 mL/min/year/10 mmHg, respectively (p < 0.05). The association was stronger in persons on antihypertensive medication than in others (p < 0.05 for the interaction between BP and antihypertensive medication).

CONCLUSIONS

In the medium-term, elevated BP is not associated with accelerated GFR decline in the general middle-aged population. In persons using antihypertensive medication, elevated BP is associated with a paradoxical slower GFR decline. Studies with even longer observation periods are needed to evaluate the ultimate effect of BP on kidney function.

Dipstick proteinuria level is significantly associated with pre-morbid and in-hospital functional status among hospitalized older adults: a preliminary study

Although chronic kidney disease (CKD) is associated with functional decline, whether proteinuria alone is associated with functional statuses over the course of acute illnesses independent of CKD is unclear. During 2014, we prospectively enrolled non-dialysis patients aged ≥65 years, and all participants underwent spot dipstick urinalysis on admission, divided into 3 groups according to the results (none, trace to 1 + , and 2 + or higher); functional status was evaluated using the pre-morbid and in-hospital Barthel index (BI) scores. Of 136 community-dwelling elderly patients enrolled (age 80.7 ± 8.2 years, with 19% having CKD), 17%, 57%, and 26% had no, trace to 1 + , or 2 + or higher proteinuria. Overall pre-morbid, on-admission, and on-discharge BI scores were 50.4 ± 41.9, 38.6 ± 31.8, and 38.7 ± 35.3, respectively with significant negative correlations with proteinuric severity on admission. Finally, multivariate linear stepwise regression analysis with backward variable selection found that dipstick proteinuric severity was significantly associated with pre-morbid, on-admission, and on-dischrage BI scores (p = 0.048, <0.01, and <0.01, respectively), independent of diabetes and CKD. This relationship between dipstick proteinuric levels and functional status of hospitalized elderly suggests an under-recognized association. Prospective evaluation of long-term outcome is needed.

Impact of achieved systolic blood pressure on renal function in hypertensive patients

Aims

There is strong evidence for the association of high blood pressure (BP) with depressed renal function. Although high BP at baseline is associated with greater progression of chronic kidney disease (CKD), randomized trials in CKD patients have found no significant relationship between more intensive BP control and glomerular filtration rate (GFR) decline. However, the relationship of GFR and change in GFR over time to lower achieved systolic BP (SBP) in hypertensive patients undergoing treatment is unclear.

Methods and results

Baseline estimated GFR (eGFR) and change in eGFR during follow-up were examined in relation to average on-treatment SBP in 8778 hypertensive patients with ECG left ventricular hypertrophy (LVH) randomly assigned to losartan- or atenolol-based treatment. GFR was estimated using the Modification of Diet in Renal Disease study equation. Patients with average on-treatment SBP ≤130 mmHg (lowest quintile at last measurement) and average SBP between 131 and 141 mmHg were compared with patients with average SBP ≥142 mmHg (median SBP at last measurement). Patients with an average on-treatment SBP ≤130 mmHg had significantly lower baseline eGFR than those with average SBP between 131 and 141 or average SBP ≥142 mmHg (65.5 ± 14.3 vs. 69.3 ± 14.3 vs. 69.0 ± 14.5 mL/min/1.73 m2, P < 0.001 using analysis of covariance adjusting for age, sex, race, randomized treatment, prior antihypertensive treatment, history of diabetes, myocardial infarction, ischaemic heart disease or heart failure, smoking status, baseline serum glucose, total and HDL cholesterol, albuminuria, and baseline LVH by Cornell product and Sokolow-Lyon voltage). However, the decrease in eGFR between baseline and Year 4 was significantly lower among patients with average SBP ≤130 mmHg (-6.3 ± 10.3 vs. -7.9 ± 11.1 vs. -9.2 ± 10.6 mL/min/1.73 m2, P = 0.001 when adjusting for the same variables and for change in Cornell product and Sokolow-Lyon voltage between baseline and Year 4). These differences in eGFR change persisted even after adjusting for baseline eGFR, and there were no significant interactions with randomized treatment, sex, race, or baseline presence of proteinuria.

Conclusion

Lower average on-treatment SBP (≤130 mmHg) was associated with a lower baseline eGFR but with a slower reduction in eGFR during 4-year follow-up in hypertensive patients with ECG LVH, independent of other possible risk factors for decreased GFR. Further study is necessary to determine whether randomized treatment to lower SBP goals is more protective of renal function than treatment to standard SBP goals.

Clinical trial registration

http://clinicaltrials.gov/ct/show/NCT00338260?order=1; unique identifier: NCT00338260.

Primacy of lowered baseline glomerular filtration rate as a risk for incident chronic kidney disease: A longitudinal study in Japanese subjects

AIM

Risk profile for incident chronic kidney disease (CKD) in Japanese subjects has not been established. Our aim was to identify risk factors for CKD in Japanese.

METHODS

Consecutive 171 536 health examinees (median age 49 years and estimated glomerular filtration rate (eGFR) 78.2 mL/min per 1.73 m² ) without CKD were re-examined after a median period of 6.2 years. Results of Cox proportional hazards models in randomly assigned two thirds (Derivation cohort) were verified in the rest (Validation cohort). CKD was defined as eGFR <60 mL/min per 1.73 m² or positive dipstick proteinuria.

RESULTS

In the Derivation cohort, CKD developed in 1002 (5.8%) subjects. Seven variables such as lower eGFR, male gender, higher uric acid concentration, lower red cell count and higher age and systolic blood pressure were identified as significant risks for CKD, with lowered eGFR being an overwhelmingly strong risk: adjusted hazard ratio for those with the baseline eGFR <70 mL/min per 1.73 m² was as high as 90.1. Performance of prediction of CKD by the probability on the basis of the seven risk factors combined was only marginally preferable to eGFR alone. The area under the receiver operating characteristic curve (95% CI) for the prediction was 0.846 (0.826-0.864) and 0.822 (0.802-0.840) (P < 0.01), the kappa statistic was 0.263 and 0.250 (n.s.), and the mean absolute difference between "predicted probability" and "observed" CKD was 1.4% and 1.9% (P = 0.14) by the combined model and eGFR alone, respectively.

CONCLUSION

Seven risk factors for incident CKD were identified in Japanese health examinees. However, lowered baseline eGFR outweighed other risks to the degree that eGFR alone was suffice for CKD prediction.

Elevated blood pressure is not associated with accelerated glomerular filtration rate decline in the general non-diabetic middle-aged population

Although hypertension is a risk factor for end-stage renal disease, this complication develops in only a minority of hypertensive patients. Whether non-malignant hypertension itself is sufficient to cause reduced glomerular filtration rate (GFR) is unclear. Therefore, we investigated whether elevated blood pressure (BP) was associated with accelerated GFR decline in the general population. The study was based on the Renal Iohexol Clearance Survey in Tromsø 6 (RENIS-T6), which included a representative sample of 1594 individuals aged 50 to 62 years from the general population without baseline diabetes or kidney or cardiovascular disease. GFR was measured as iohexol clearance at baseline and follow-up after a median observation time of 5.6 years. BP was measured according to a standardized procedure. The mean (SD) GFR decline rate was 0.95 (2.23) ml/min/yr. In multivariable adjusted linear mixed regressions with either baseline systolic or diastolic BP as the independent variable, there were no statistically significant associations with GFR decline. Thus, elevated BP is not associated with accelerated mean GFR decline in the general middle-aged population. Hence, additional genetic and environmental factors are probably necessary for elevated BP to develop manifest chronic kidney disease in some individuals.

Hypertension and Prehypertension and Prediction of Development of Decreased Estimated GFR in the General Population: A Meta-analysis of Cohort Studies

BACKGROUND

Whether blood pressure (BP) plays an independent predictive role in the onset of decreased glomerular filtration rate (GFR) remains ill-defined because existing meta-analyses have incorporated data from studies that included individuals with low GFRs at baseline. This question is critical to optimize chronic kidney disease prevention in the general population.

STUDY DESIGN

Systematic review and meta-analysis of longitudinal cohort studies.

SETTING & POPULATION

Adults from general population.

SELECTION CRITERIA FOR STUDIES

We identified in PubMed, EMBASE, and the Cochrane Library database all cohort studies evaluating the role of BP in the incidence of decreased estimated GFR (eGFR; defined as eGFR<60 mL/min/1.73 m2) in individuals without decreased kidney function at baseline.

PREDICTORS

Hypertension (BP>140/90 mmHg), prehypertension (systolic BP of 120-139 and/or diastolic BP of 80-89 mmHg), and BP as a continuous variable.

OUTCOMES

Risk for decreased eGFR reported as relative risk (RR) and 95% CI. Heterogeneity (I2) was also evaluated.

RESULTS

Data from 16 cohorts (315,321 participants) were analyzed. All studies had a Newcastle-Ottawa score in the range of 6 to 8, denoting high quality. During a mean follow-up of 6.5 years, decreased eGFR occurred in 6.6% of participants. The presence of prehypertension and hypertension increased renal risk (RRs of 1.19 [95% CI, 1.07-1.33; I2=23.8%] and 1.76 [95% CI, 1.58-1.97; I2=37.7%], respectively). Similarly, we found that every 10-mm Hg increase in systolic and diastolic BPs associated with higher risk for decreased eGFR (RRs of 1.08 [95% CI, 1.04-1.11; I2=60.0%] and 1.12 [95% CI, 1.04-1.20; I2=51.4%], respectively). Metaregression analysis showed greater risk with older age (P=0.03), whereas other covariates were not significant.

LIMITATIONS

No individual patient-level data.

CONCLUSIONS

Prehypertension and hypertension, as BP levels, are independent predictors of decreased GFR in the general population, with the effect being more pronounced in the elderly. These findings are important for improving risk stratification in the general population.