Office and Ambulatory Heart Rate as Predictors of Age-Related Kidney Function Decline

Rate of decline in kidney function with age: a systematic review

OBJECTIVE

To determine the distribution of kidney function values as measured by glomerular filtration rate (GFR), and the rate of decline with age in male and female healthy subjects without pre-existing medical conditions.

DESIGN

Systematic review and structured synthesis.

SEARCH SOURCES

PubMed, Embase, Cochrane Central Register of Controlled Trials and Web of Science, from database inception to 25 October 2023. Unpublished studies were searched from clinical trial registries and the grey literature.

SELECTION CRITERIA

Observational cohort studies, including non-treatment arms of randomised, pseudorandomised and non-randomised controlled trials that assessed the age-related decline in kidney function over time.

MAIN OUTCOME MEASURES

Primary outcomes were rate of change of kidney function over time (absolute and relative change) and rate of change of kidney function with age. Secondary outcomes included rate of change of kidney function compared with baseline GFR, gender, ethnicity and proportion of participants >60 years defined as having chronic kidney disease.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened studies for inclusion, extracted data and assessed risk of bias. Data could not be pooled because of significant heterogeneity. Instead, a descriptive analysis was used to synthesise results.

RESULTS

12 studies between 1958 and 2021 reported the decline rate of kidney function in healthy individuals: six prospective cohort studies, four retrospective cohort studies and two randomised controlled clinical trials, which included 129 359 healthy participants (range from 15 to 46 682) and ranged from 2 to 23 years duration. Annual decline rates ranged from -0.24 to -3.60 mL/min/1.73 m2/year (-0.37 to -1.07 in subjects without hypertension). Results were mixed as to whether decline rates sped up or slowed down with age, and whether decline rates differed between women and men, with studies showing conflicting results. This study was unable to determine the decline rates in different ethnicities.

CONCLUSIONS

This study is the first systematic review to investigate the longitudinal decline in kidney function with age in healthy individuals. The normal decline rate could be considered between -0.37 and -1.07 mL/min/1.73 m2/year in healthy adults without hypertension. Kidney function decline rates in healthy adults may be helpful to clinicians anticipating patients' kidney trajectory and determining whether chronic kidney disease-specific care is required.

PROSPERO REGISTRATION NUMBER

CRD42023096888.

Resting Heart Rate Independent of Cardiovascular Disease Risk Factors Is Associated With End-Stage Renal Disease: A Cohort Study Based on 476 347 Adults

BACKGROUND

The relationship between resting heart rate (RHR) and the risk of end-stage renal disease (ESRD) among those without cardiovascular disease remains unclear. We aim to establish temporal consistency and elucidate the independent relationship between RHR and the risk of ESRD.

METHODS AND RESULTS

This cohort enrolled participants from 476 347 individuals who had taken part in a screening program from 1996 to 2017. We identified 2504 participants who had ESRD, and the median follow-up was 13 years. RHR was extracted from electrocardiography results, and the study assessed the relationship between RHR and the risk of ESRD using the Cox proportional hazards model. Of the participants, 32.6% had an RHR of 60 to 69 beats per minute (bpm), and 22.2% had an RHR of ≥80 bpm. Participants with an RHR of ≥80 bpm had a higher stage of chronic kidney disease, lower estimated glomerular filtration rate, and more proteinuria than those with an RHR of 60 to 69 bpm. Participants with an RHR of 80 to 89 and ≥90 bpm had a 24% (hazard ratio [HR], 1.24 [95% CI, 1.09-1.42]) and 64% (HR, 1.64 [95% CI, 1.42-1.90]) higher risk of ESRD, respectively. The risk of ESRD remained significantly elevated (HR, 1.32 [95% CI, 1.10-1.58] per 10-beat increase from 60 bpm) after excluding participants who smoked; had hypertension, diabetes, or hyperlipidemia; or were overweight.

CONCLUSIONS

An RHR of ≥80 bpm is significantly associated with an increased risk of ESRD. These results suggest that RHR may serve as a risk factor for kidney disease in individuals without established cardiovascular disease risk factors.

Nocturnal heart rate rising is a risk factor for poor renal outcomes in patients with chronic kidney disease and hypertension

The association of heart rate (HR) dipping pattern with renal outcomes in chronic kidney disease (CKD) patients with hypertension has never been investigated. In order to demonstrate if HR dipping pattern is a risk factor for renal outcomes, cardiovascular (CV) diseases, and mortality in hypertensive patients with CKD, we conducted the prospective longitudinal observational study. Patients were divided into three groups according to their nocturnal HR: HR dippers (night-day HR ratio ≤ 0.9), HR non-dippers (0.9 < night-day HR ratio ≤ 1.0), and HR risers (night-day HR ratio > 1.0). The primary outcome was renal endpoint, a composite outcome of progression to end-stage renal disease (ESRD) or estimated glomerular filtration rate (eGFR) decline ≥ 50%; the secondary outcomes included poor renal outcomes, CV events, and death. A total of 34 (11.3%) patients reached renal endpoint after a follow-up of 34 ± 17 months. Both HR non-dippers and HR risers were predictive to renal endpoint (hazard ratio 2.58, 95% confidence interval (CI) 1.04- 6.4, P = .04; hazard ratio 3.95, 95% CI 1.33- 11.79, P = .01, respectively), while only HR risers was shown to be correlated with a decline in eGFR≥ 50% (hazard ratio 5.28, 95% CI 1.45-19.16, P < .05), and decline in eGFR (β -0.17, 95% CI -0.33- -0.01, P = .04). No predictive value was found for HR dipping pattern to mortality and CV events. In conclusion, our study provided the first evidence that HR non-dippers, especially risers were a risk factor for poor renal outcomes in hypertensive patients with CKD.

Serum Matrix Metalloproteinase 7 and accelerated GFR decline in a general non-diabetic population

BACKGROUND

Age-related reduction of glomerular filtration rate (GFR) is a major contributor to the global chronic kidney disease (CKD) epidemic. We investigated whether baseline serum levels of the pro-fibrotic matrix metalloproteinase 2 (MMP2), MMP7 and their inhibitor, tissue inhibitor of metalloproteinase 1 (TIMP1), which mediates fibrosis development in aging animals, were associated with GFR decline in a general nondiabetic population.

METHODS

In the Renal Iohexol Clearance Survey (RENIS), we measured GFR using iohexol clearance in 1627 subjects aged 50-64 without self-reported diabetes, kidney or cardiovascular disease. After a median of 5.6 years, 1324 had follow-up GFR measurements. Using linear mixed models and logistic regression analyses, we evaluated the association of MMP7, MMP2 and TIMP1 with the mean GFR decline rate, risk of accelerated GFR decline (defined as subjects with the 10% steepest GFR slopes: ≥1.8 ml/min/1.73 m2/year) and incident CKD (GFR <60 ml/min/1.73 m2 and/or urinary albumin to creatinine ratio (ACR) ≥3.0 mg/mmol).

RESULTS

Higher MMP7 levels (per SD increase of MMP7) were associated with steeper GFR decline rates (-0.23 ml/min/1.73m2/year [95% confidence interval, -0.34 to -0.12]) and increased risk of accelerated GFR decline and incident CKD, (odds ratios; 1.58 (1.30-1.93) and 1.45 (1.05-2.01), respectively, in a model adjusted for age, sex, baseline GFR, ACR and cardiovascular risk factors). MMP2 and TIMP1 showed no association with GFR decline or incident CKD.

CONCLUSION

The pro-fibrotic biomarker MMP7, but not MMP2 or TIMP1, is associated with increased risk of accelerated GFR decline and incident CKD in middle-aged persons from the general population.