Graded Association Between Kidney Function and Impaired Orthostatic Blood Pressure Stabilization in Older Adults

Chronic kidney disease and orthostatic hypotension in hospitalised older adults

PURPOSE

Orthostatic hypotension (OH) may predispose older adults to health complications leading to functional impairment. Despite the central role of the kidney in blood pressure control, the contribution of renal function in orthostatic hypotension is poorly investigated. To verify the association between Chronic Kidney Disease (CKD) and OH a population of hospitalised elderly patients with comorbidities was studied.

MATERIALS AND METHODS

174 patients were consecutively admitted to Acute Geriatric Wards. On admission, patients underwent postural systolic (SBP) and diastolic (DBP) blood pressure evaluation by automatic oscillometric device after 10 min rest in lying position, and in standing position at time 0, 1, 3 and 5 min. CKD was assumed for estimated glomerular filtration rate (e-GFR) less than 60 mL/min/1.73 m2.

RESULTS

The mean age of the population enrolled was 74.4 ± 7.0. OH was found in 46.0% and CKD in 56.3% of patients, respectively. A lower e-GFR was observed in patients with (56.1 ± 16.7 mL/min/1.73 m2) than in those without OH (61.1 ± 15.9 mL/min/1.73 m2) (p < 0.05). A greater fall in SBP at 0-min (12.8 ± 6.3 vs. 7.7 ± 3.2 mmHg) and at 1-min (8.4 ± 4.5 vs. 5.7 ± 2.8 mmHg) was found in CKD patients in respect to patients without CKD during active standing test (p < 0.05). Similarly, a DBP reduction at 0-min and at 1-min was observed in CKD patients in respect to patients without CKD (p < 0.05). A multivariate logistic regression analysis showed that CKD was associated to OH (OR 2.426; 95%CI 1.192-4.937; p = 0.014).

CONCLUSIONS

CKD is associated to OH in hospitalised older adults.

Effect of Orthostatic Hypotension on Kidney Function

BACKGROUND

The association between orthostatic hypotension (OH) and long-term changes in kidney function in the general population is not yet well known.

METHODS

We performed a population-based cohort study based on data from the Korean Genome and Epidemiology Study (KoGES). The primary exposure was the presence of classic OH, defined as a postural drop in blood pressure (systolic blood pressure ≥20 mm Hg and/or diastolic blood pressure ≥10 mm Hg) at 2 min of standing after 5 min of supine rest. The primary outcome was a 12-year change in kidney function, assessed by subtracting the baseline estimated glomerular filtration rate (eGFR) from the eGFR at 12 years of follow-up.

RESULTS

Our study included 5,905 participants (median [interquartile range] age, 49 [44-58] years; 46% males) who met inclusion and exclusion criteria. Classic OH was detected in 268 (4.5%) of the total participants. In the regression analyses, participants with classic OH had a greater decline in eGFR over 12 years compared with those without classic OH; the fully adjusted beta coefficient and 95% confidence intervals (95% CIs) were -1.74 (-3.07, -0.40). Furthermore, classic OH was associated with 27% greater risk of a 30% decline in kidney function compared with those without classic OH; fully adjusted hazard ratio and 95% CIs were 1.27 (1.07, 1.49).

CONCLUSIONS

Classic OH can negatively affect long-term kidney function in the general population.

Biomarker Signatures of Two Phenotypical Prefrailty Types in the Irish Longitudinal Study on Ageing

We investigated the biomarker signatures of two previously reported phenotypical prefrailty (PF) types in the first wave of The Irish Longitudinal Study on Ageing (TILDA): PF1 (unexplained weight loss and/or exhaustion) and PF2 (one or two among slowness, weakness, and low physical activity). Binary logistic regression models evaluated the independent associations between available plasma biomarkers and each PF type (compared to robust and compared to each other), while adjusting for age, sex, and education. A total of 5307 participants were included (median age 61 years, 53% women) of which 1473 (28%) were prefrail (469 PF1; 1004 PF2), 171 were frail, and 3663 were robust. The PF2 median age was eight years older than the PF1 median age. Higher levels of lutein and zeaxanthin were independently associated with the lower likelihood of PF1 (OR: 0.77, p < 0.001 and OR: 0.81, p < 0.001, respectively). Higher cystatin C was associated with PF1 (OR: 1.23, p = 0.001). CRP (OR: 1.19, p < 0.001), cystatin C (OR: 1.36, p < 0.001), and HbA1c (OR: 1.18, p < 0.001) were independently associated with PF2, while a higher total (OR: 0.89, p = 0.004) and HDL (OR: 0.87, p < 0.001) cholesterol seemed to be PF2-protective. While PF1 seemed to be inversely associated with serum carotenoid concentrations and hence has an oxidative signature, PF2 seemed to have pro-inflammatory, hyperglycemic, and hypolipidemic signatures. Both PF types were associated with higher cystatin C (lower kidney function), but no biomarkers significantly distinguished PF1 vs. PF2. Further research should elucidate whether therapies for different PF types may require targeting of different biological pathways.

Cognitive Impairment in End Stage Renal Disease Patients Undergoing Hemodialysis: Markers and Risk Factors

(1) Background: Cognitive impairment (CI) is common in chronic kidney disease (CKD) and patients treated with hemodialysis. (2) Methods: The systematic review was prepared following the PRISMA statement (2013). The biomedical electronic databases MEDLINE and SCOPUS were searched. (3) Results: out of 1093 studies, only 30, which met problem and population criteria, were included in this review. The risk factors for CI can be divided into three groups: traditional risk factors (present in the general population), factors related to dialysis sessions, and nontraditional risk factors occurring more frequently in the HD group. (4) Conclusions: the methods of counteracting CI effective in the general population should also be effective in HD patients. However, there is a need to develop unique anti-CI approaches targeting specific HD risk factors, i.e., modified hemodialysis parameters stabilizing cerebral saturation and blood flow.

Impaired Stabilisation of Orthostatic Cerebral Oxygenation is Associated with Slower Gait Speed: Evidence from The Irish Longitudinal Study on Ageing

Background

Cerebral autoregulation (CAR) systems maintain blood flow to the brain across a wide range of blood pressures. Deficits in CAR have been linked to gait speed (GS) but previous studies had small sample sizes and used specialized equipment which impede clinical translation. The purpose of this work was to assess the association between GS and orthostatic cerebral oxygenation in a large, community-dwelling sample of older adults.

Method

Data for this study came from the Irish Longitudinal Study on Ageing. A near-infrared spectroscopy (NIRS) device attached to the forehead of each participant (n = 2 708) was used to track tissue saturation index (TSI; the ratio of oxygenated to total hemoglobin) during standing. GS was assessed using a portable walkway.

Results

Recovery was impaired in slower GS participants with a TSI value at 20 seconds (after standing) of −0.55% (95% CI: −0.67, −0.42) below baseline in the slowest GS quartile versus −0.14% (95% CI: −0.25, −0.04) in the fastest quartile. Slower GS predicted a lower TSI throughout the 3-minute monitoring period. Results were not substantially altered by adjusting for orthostatic hypotension. Adjustment for clinical and demographic covariates attenuated the association between but differences remained between GS quartiles from 20 seconds to 3 minutes after standing.

Conclusion

This study reported evidence for impaired recovery of orthostatic cerebral oxygenation depending on GS in community-dwelling older adults. Future work assessing NIRS as a clinical tool for monitoring the relationship between GS and cerebral regulation is warranted.

One-Dimensional Statistical Parametric Mapping Identifies Impaired Orthostatic Cerebrovascular and Cardiovascular Response in Frailty Index

Background

Orthostasis is a potent physiological stressor which adapts with age. The age-related accumulation of health deficits in multiple physiological systems may impair the physiological response to orthostasis and lead to negative health outcomes such as falls, depression, and cognitive decline. Research to date has focused on changes with orthostasis at prespecified intervals of time, without consideration for whole signal approaches.

Methods

One-dimensional statistical parametric mapping identified regions in time of significant association between variables of interest using a general linear model. Frailty index operationalized accumulated health and social deficits using 32-items from a computer-assisted interview. This study examined the association of frailty index on blood pressure, heart rate, and cerebral oxygenation during an orthostatic test in a sample of 2742 adults aged 50 or older from The Irish Longitudinal Study on Ageing.

Results

Frailty index was seen to be negatively associated with cerebral oxygenation changes from baseline over a period of 7 seconds (p = .036). Heart rate and systolic blood pressure were positively and negatively associated with frailty index over periods of 17 seconds (p = .001) and 10 seconds (p = .015), respectively.

Conclusions

Statistical parametric mapping demonstrated these significant regions of cerebral oxygenation during orthostasis provide indirect evidence of impaired autoregulation associated with frailty. Statistical parametric mapping also replicated prior relationships in heart rate and systolic blood pressure associated with a higher frailty index. These findings highlight the utility of 1-dimensional statistical parametric modeling in identifying significant regions of interest in physiological recordings.

Orthostatic Hypertension and Hypotension and Outcomes in CKD: The CRIC (Chronic Renal Insufficiency Cohort) Study

Rationale & Objective

There are limited data about the prevalence and prognostic significance of orthostatic hypo- and hypertension in patients with chronic kidney disease. The objective of this study is to determine the prevalence of orthostatic hypo- and hypertension in a cohort of patients with chronic kidney disease and examine their association with clinical outcomes.

Study Design

Prospective cohort study: Chronic Renal Insufficiency Cohort (CRIC) Study.

Setting & Population

7 clinical centers, participants with chronic kidney disease.

Exposures

Orthostatic hypotension (decline in systolic blood pressure [BP] > 20 mm Hg) and orthostatic hypertension (increase in systolic BP > 20 mm Hg) from seated to standing position.

Outcomes

Cardiovascular and kidney outcomes and mortality.

Analytical Approach

Logistic regression was used to determine factors associated with orthostatic hypo- and hypertension; Cox regression was used to examine associations with clinical outcomes.

Results

Mean age of study population (n = 3,873) was 58.1 ± 11.0 years. There was a wide distribution of change in systolic BP from seated to standing (from −73.3 to +60.0 mm Hg); 180 participants (4.6%) had orthostatic hypotension and 81 (2.1%) had orthostatic hypertension. Diabetes, reduced body mass index, and β-blocker use were independently associated with orthostatic hypotension. Black race and higher body mass index were independently associated with orthostatic hypertension. After a median follow-up of 7.9 years, orthostatic hypotension was independently associated with high risk for cardiovascular (HR, 1.12; 95% CI, 1.03-1.21) but not kidney outcomes or mortality. Orthostatic hypertension was independently associated with high risk for kidney (HR, 1.51; 96% CI, 1.14-1.97) but not cardiovascular outcomes or mortality.

Limitations

Orthostatic change in BP was ascertained at a single visit.

Conclusions

Orthostatic hypotension was independently associated with higher risk for cardiovascular outcomes, whereas orthostatic hypertension was associated with higher risk for kidney outcomes. These findings highlight the importance of orthostatic BP measurement in practice and the need for future investigation to understand the mechanisms and potential interventions to minimize the risk associated with orthostatic changes in BP.

Orthostatic hypotension among elderly patients in Italian internal medicine wards: an observational study

Orthostatic hypotension (OH) is a multifactorial disorder, often asymptomatic. The prevalence of OH increases with age, ranging from 5 to 11% among middle-aged patients to 55% in the frail elderly depending on age and associated comorbidities. OH is often unrecognized or misdiagnosed and little is known about its prevalence in hospitalized elderly patients. Our aims were: (1) to determine the prevalence of OH in a cohort of elderly patients hospitalized in two internal medicine wards in Italy; (2) and to describe their characteristics and symptoms. During the 5 months from March 1, 2017 to July 31, 2017, the first 85 consecutive patients (65 years or older) admitted in two internal medicine wards were enrolled. Patients were included in the study if they were able to get out of bed alone or with minor assistance, and able to stand up for at least 3 min. The study population comprised 85 patients with a mean age of 79.6 ( ± 7.2) years. OH was found in 64 (75.3%), occasional OH in 41 (48.2%), persistent OH in 23 (27.1%), and 21 (24.7%) patients had no OH. All patients had diastolic OH and 37 (57.8%) also systolic. Patients with persistent OH were oldest, with a higher percentage of renal failure. Twenty-six patients (40.6%) with OH reported symptoms. Dizziness was the most common symptom, especially after breakfast. No association was found between type of medications and risk of OH. Mortality risk was not statistically different between patients with or without OH 3 (p = 0.10) and 6 months after discharge (p = 0.18), but a trend was observed. We found that OH is very common in the patients admitted in the internal medicine wards, particularly diastolic OH. Close attention should be paid to OH and its symptoms, especially dizziness, in the oldest-old patients, and in patients with renal failure.

Classical and Delayed Orthostatic Hypotension in Patients With Unexplained Syncope and Severe Orthostatic Intolerance

Background: Orthostatic hypotension (OH) is a major sign of cardiovascular autonomic failure leading to orthostatic intolerance and syncope. Orthostatic hypotension is traditionally divided into classical OH (cOH) and delayed OH (dOH), but the differences between the two variants are not well-studied. We performed a systematic clinical and neuroendocrine characterization of OH patients in a tertiary syncope unit.

Methods: Among 2,167 consecutive patients (1,316 women, 60.7%; age, 52.6 ± 21.0 years) evaluated for unexplained syncope and severe orthostatic intolerance with standardized cardiovascular autonomic tests including head-up tilt (HUT), we identified those with a definitive diagnosis of cOH and dOH. We analyzed patients' history, clinical characteristics, hemodynamic variables, and plasma levels of epinephrine, norepinephrine, C-terminal-pro-arginine-vasopressin (CT-proAVP), C-terminal-endothelin-1, mid-regional-fragment of pro-atrial-natriuretic-peptide and pro-adrenomedullin in the supine position and at 3-min HUT.

Results: We identified 248 cOH and 336 dOH patients (27% of the entire cohort); 111 cOH and 152 dOH had blood samples collected in the supine position and at 3-min HUT. Compared with dOH, cOH patients were older (68 vs. 60 years, p < 0.001), more often male (56.9 vs. 39.6%, p < 0.001), had higher systolic blood pressure (141 vs. 137 mmHg, p = 0.05), had lower estimated glomerular filtration rate (73 vs. 80 ml/min/1.73 m², p = 0.003), more often pathologic Valsalva maneuver (86 vs. 49 patients, p < 0.001), pacemaker-treated arrhythmia (5 vs. 2%, p = 0.04), Parkinson's disease (5 vs. 1%, p = 0.008) and reported less palpitations before syncope (16 vs. 29%, p = 0.001). Supine and standing levels of CT-proAVP were higher in cOH (p = 0.022 and p < 0.001, respectively), whereas standing norepinephrine was higher in dOH (p = 0.001). After 3-min HUT, increases in epinephrine (p < 0.001) and CT-proAVP (p = 0.001) were greater in cOH, whereas norepinephrine increased more in dOH (p = 0.045).

Conclusions: One-quarter of patients with unexplained syncope and severe orthostatic intolerance present orthostatic hypotension. Classical OH patients are older, more often have supine hypertension, pathologic Valsalva maneuver, Parkinson's disease, pacemaker-treated arrhythmia, and lower glomerular filtration rate. Classical OH is associated with increased vasopressin and epinephrine during HUT, but blunted increase in norepinephrine.

Impact of Standing Speed on the Peripheral and Central Hemodynamic Response to Orthostasis: Evidence From the Irish Longitudinal Study on Ageing

Assessment of the cerebrovascular and cardiovascular response to standing has prognostic value for a range of outcomes in the older adult population. Studies generally attempt to control for standing speed differences by asking participants to stand in a specified time but little is known about the range of transition times observed. This study aimed to characterize how standing speed associates with cardiovascular and cerebrovascular measures following transition from supine to standing. Continuous cerebral oxygenation, heart rate, systolic and diastolic blood pressure were monitored for 3 minutes after transitioning from supine to standing. An algorithm was used to calculate the time taken to transition from existing Finometer data (from the height correction unit). Linear mixed-effects models were used to assess the influence of transition time on each of the signals while adjusting for covariates. Transition time ranged from 2 to 27 s with 17% of participants taking >10 s to stand. Faster transition was associated with a more extreme decrease 10 s after standing but improved recovery at 20 s for cerebral oxygenation and blood pressure. Standing faster was associated with an elevated heart rate on initiation of stand and a quicker recovery 10 to 20 s after standing. The speed of transitioning from supine to standing position is associated with cardiovascular and cerebrovascular response in the early period after standing (<40 s). Care should be taken in the interpretation of findings which may be confounded by standing speed and statistical adjustment for standing time should be applied where appropriate.