High Estimated Glomerular Filtration Rate Is Associated With Worse Cognitive Performance in the Hypertensive Population: Results From the China H-Type Hypertension Registry Study

H-type Hypertension Status and Influencing Factors of the Elderly People Over 80 Years Old Based on Random Forest Model

Hypertension is a common chronic disease in elderly people over 80 years old. Clinically, H-type hypertension occurs when hypertension coexists with hyperhomocysteinemia level of ≥ 10 umol/L. Effective identification of risk factors for H-type hypertension in the elderly can greatly improve patient prognosis.Consecutively, 494 patients with hypertension admitted to the Fourth Affiliated Hospital of Harbin Medical University from January 2019 to December 2021 were selected as the study population. They were divided into H-type hypertension (n = 197) and non-H-type hypertension groups (n = 297). Patient data were collected, including basic information, history, and clinical data. The random forest model and LASSO analysis were used to screen the influencing factors for H-type hypertension. Multiple stepwise regression analysis was used to analyze the selected variables.A total of 197 elderly people over 80 years old suffered from H-type hypertension, with an incidence rate of 39.88%. The random forest model and LASSO analysis results showed that the top 8 independent variables in importance ranking were ejection fraction (EF), fibrinogen, glycated hemoglobin (HbA1c), B-type natriuretic peptide, creatinine, fasting blood glucose, uric acid, and serum triiodothyronine levels. The results of multivariate analysis showed that EF was the protective factor, while fibrinogen, HbA1c, and creatinine were the risk factors for H-type hypertension in elderly people over 80 years old (P < 0.05).Healthcare professionals can indirectly assess the prevalence of H-type hypertension by focusing on EF, fibrinogen, creatinine, and HbA1c in elderly hypertensive patients. This provided proactive intervention and medical services to improve prognosis outcomes.

The estimated glomerular filtration rate was U-shaped associated with abdominal aortic calcification in US adults: findings from NHANES 2013-2014

Objectives

The high incidence of abdominal aortic calcification (AAC) is well-documented in individuals with severe renal function decline. However, there is limited research on the historical relationship between estimated glomerular filtration rate (eGFR) and the risk of AAC occurrence in the general population undergoing routine medical examinations. The main objective of this study was to investigate the historical relationship between eGFR and AAC in the general population of the United States.

Methods

We performed a cross-sectional study using the National Health and Nutrition Examination Survey 2013-2014 database. Weighted multivariate linear regression models were used to estimate the associations of eGFR with AAC score. Smooth curve fitting and two-piecewise linear regression were employed to explore the potential non-linear relationship.

Results

A total of 2,978 participant (48.22% were male) aged 40-80 years were included in this study. The fully-adjusted model demonstrated a negative correlation between eGFR and AAC score (β = -0.015, 95% CI: -0.023 to -0.006). However, when applying the smooth curve fitting method, a U-shaped relationship was identified, and the inflection point was calculated at 76.43 ml/min/1.73 m2 using the two-piecewise linear regression model.

Conclusions

There was a U-shaped association between eGFR and AAC score in general US adults, with an inflection point at about 76.43 ml/min/1.73 m2.

Kidney function, albuminuria, and their modification by genetic factors and risk of incident dementia in UK Biobank

BACKGROUND

Associations between kidney function and dementia risk are inconclusive. Chronic kidney disease (CKD) severity is determined by levels of both estimated glomerular filtration rate (eGFR) and the urine albumin to creatinine ratio (ACR). However, whether there is a graded increase in dementia risk for worse eGFR in each ACR category is unclear. Also, whether genetic risk for dementia impacts the associations is unknown. The current study aims to investigate the associations between eGFR and albuminuria with dementia risk both individually and jointly, whether the associations vary by different follow-up periods, and whether genetic factors modified the associations.

METHODS

In 202,702 participants aged ≥ 60 years from the UK Biobank, Cox proportional-hazards models were used to examine the associations between eGFR and urine albumin creatinine ratio (ACR) with risk of incident dementia. GFR was estimated based on serum creatinine, cystatin C, or both. The models were restricted to different follow-up periods (< 5 years, 5-10 years, and ≥ 10 years) to investigate potential reverse causation.

RESULTS

Over 15 years of follow-up, 6,042 participants developed dementia. Decreased kidney function (eGFR < 60 ml/min/1.73m2) was associated with an increased risk of dementia (Hazard Ratio [HR] = 1.42, 95% Confidence Interval [CI] 1.28-1.58), compared to normal kidney function (≥ 90 ml/min/1.73m2). The strength of the association remained consistent when the models were restricted to different periods of follow-up. The HRs for incident dementia were 1.16 (95% CI 1.07-1.26) and 2.24 (95% CI 1.79-2.80) for moderate (3-30 mg/mmol) and severely increased ACR (≥ 30 mg/mmol) compared to normal ACR (< 3 mg/mmol). Dose-response associations were observed when combining eGFR and ACR, with those in the severest eGFR and ACR group having the greatest risk of dementia (HR = 4.70, 95% CI 2.34-9.43). APOE status significantly modified the association (p = 0.04), with stronger associations observed among participants with a lower genetic risk of dementia. There was no evidence of an interaction between kidney function and non-APOE polygenic risk of dementia with dementia risk (p = 0.42).

CONCLUSIONS

Kidney dysfunction and albuminuria were individually and jointly associated with higher dementia risk. The associations were greater amongst participants with a lower genetic risk of dementia based on APOE, but not non-APOE polygenic risk.

Novel insights in classic versus relative glomerular hyperfiltration and implications on pharmacotherapy

PURPOSE OF REVIEW

Glomerular filtration rate (GFR) assessment and its estimation (eGFR) is a long-lasting challenge in medicine and public health. Current eGFR formulae are indexed for standardized body surface area (BSA) of 1.73 m2, ignoring persons and populations wherein the ratio of BSA or metabolic rate to nephron number might be different, due to increased BSA, increased metabolic rate or reduced nephron number. These equations are based on creatinine, cystatin C or a combination of the two, which adds another confounder to eGFR assessment. Unusually high GFR values, also known as renal hyperfiltration, have not been well defined under these equations.

RECENT FINDINGS

Special conditions such as solitary kidney in kidney donors, high dietary protein intake, obesity and diabetes are often associated with renal hyperfiltration and amenable to errors in GFR estimation. In all hyperfiltration types, there is an increased intraglomerular pressure that can be physiologic, but its persistence over time is detrimental to glomerulus leading to progressive glomerular damage and renal fibrosis. Hyperfiltration might be underdiagnosed due to BSA standardization embedded in the formula. Hence, timely intervention is delayed. Reducing intraglomerular pressure in diabetes can be achieved by SGLT2 inhibitors or low protein diet to reverse the glomerulopathy process.

SUMMARY

Accurate identification of glomerular hyperfiltration as a pre-CKD condition needs accurate estimation of GFR in the above normal range should establish a threshold for timely intervention.

Cardiovascular Risk Related to Glomerular Hyperfiltration in Nondiabetic Individuals: Increasing Visibility is Crucial

Glomerular hyperfiltration (GHF), defined by different estimation formulas, has been widely studied as a predictor of proteinuria and progression to chronic kidney disease (CKD) in diabetic patients. GHF is also an important cardiovascular (CV) risk factor and is related to allcause mortality in non-diabetic populations; however, the upper limit of glomerular filtration rate (GFR) above which it indicates the presence of GHF is weakly defined. This higher risk is as high as in the intermediate stages of CKD and is greater than the presence of diabetes or smoking and is still present in non-albuminuria patients. The original Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) estimation GFR formula showed lower error at higher glomerular filtration (GF) values, was the most used in population studies, and behaved as a better risk predictor. In our review (including approximately 3.6 million individuals), higher GFR values related to increased mortality risk varied from 106.6 to 113.7 ml/min, which are usually not considered risk values for standard guidelines in non-albuminuric patients. However, the lack of consensus on a GF cutoff value, as well as its variability due to sex and progressive reduction with age, affect the knowledge of this serious phenomenon in clinical practice. Although the elderly population is not exempted from the effects of GHF, the search for this phenomenon should be intensified in middle-aged populations because of their lower disease burden, where this situation may be more evident, and the possibility of reversing the consequences is greater. A population group often considered healthy includes obese people, essential hypertensives, smokers, and carriers of fatty liver, where the GHF phenomenon is frequent and is associated with CV disease, kidney disease, and higher mortality. Increasing its visibility by the medical community is essential to reduce the effects of GHF, emphasizing more frequent controls and implementing general measures that include strict control of hypertension, Na restriction, rich in vegetables diets and increased physical activity. Initiatives to confirm the beneficial effects of sodium-glucose cotransporter-2 inhibitors to treat isolated GHF would be an important breakthrough in reducing the severe consequences of this phenomenon.