Association among kidney function, frailty, and oral function in patients with chronic kidney disease: a cross-sectional study

A Causal Association Study Between Chronic Kidney Disease and Oral Health: A Mendelian Randomization Study

Background and Aims

Previous studies have shown that chronic kidney disease (CKD) can lead to changes in oral health, but the conclusions remain controversial. Thus, we conducted a Mendelian randomization (MR) study from the perspective of genetic analysis to assess the causal association between CKD and oral health conditions, including dental caries, pulp diseases, periapical tissues, and diseases of the gum and periodontal tissues.

Methods

We performed inverse variance weighted (IVW) random effects MR analyses and several sensitivity MR analyses using summary statistics from genome-wide association studies (GWAS). The data were derived from the European population in 2021, which included 3902 cases of CKD, 4170 cases of dental caries, 5354 cases of diseases of the pulp and periapical tissues, and 4120 cases of gingivitis and periodontal diseases.

Results

We found a positive causal relationship between CKD and dental caries, and the effect odds ratio (OR) of CKD on dental caries was 1.368 (95% CI, 1.124-1.664; p = 0.002). There was no direct causal relationship between CKD and diseases of the pulp and periapical tissues and diseases of the gum and periodontal tissues, with the effect OR of 1.176 (95% CI, 0.973-1.420; p = 0.094) and 1.201 (95% CI, 0.977-1.477; p = 0.08).

Conclusions

Our findings suggest that CKD could affect oral health and only with a direct causal link to dental caries. However, pulp diseases, periapical tissues, and diseases of the gum and periodontal tissues have no direct causal relationship.

Association of Physiological Reserve Obtained from Cardiopulmonary Exercise Testing and Frailty with All-Cause Mortality in Patients on Hemodialysis

Key Points

This study analyzed the prognostic value of reserves obtained from cardiopulmonary exercise testing in patients on hemodialysis. Each reserve (cardiac, autonomic, and muscular) was associated with mortality, with muscle reserve having the highest prognostic accuracy. Patients with physical frailty also had a fairly good prognosis if their physiological reserve is preserved by exercise testing.

Background

Potential impairment of exercise capacity is prevalent even in patients undergoing hemodialysis without frailty. Cardiopulmonary exercise testing (CPET) can detect physiological reserves, such as cardiopulmonary, muscle, and autonomic function. We hypothesized that these indices could accurately determine the prognosis of patients on hemodialysis and analyzed them on the basis of their relationship to frailty.

Methods

In this two-center prospective cohort study of patients on hemodialysis from Japan, patients underwent CPET and physical assessment to evaluate peak oxygen uptake (peak VO2, indicator of exercise capacity), peak work rate (WR, indicator of muscle function), ventilatory equivalent for carbon dioxide (VE/VCO2) slope (indicator of cardiac reserve), heart rate reserve (indicator of chronotropic incompetence), and frailty phenotype. Survival was followed up for up to 5 years.

Results

Data from 189 patients (median [interquartile range] age: 71 [62–77] years) were analyzed. All CPET indicators showed a consistent nonlinear relationship with all-cause mortality after adjustment: for peak VO2, hazard ratio (HR), 0.79 (95% confidence interval [CI], 0.71 to 0.88), P < 0.001; for peak WR, HR, 0.95 (95% CI, 0.93 to 0.97), P < 0.001; for VE/VCO2 slope, HR, 1.09 (95% CI, 1.05 to 1.13), P < 0.001; and for heart rate reserve, HR, 0.96 (95% CI, 0.93 to 0.99), P = 0.02. Frailty phenotype was associated with mortality after adjustment (HR, 1.73 [95% CI, 1.06 to 2.81], P = 0.03); however, this association was not statistically significant in the model after adding peak VO2 (P = 0.41). Furthermore, in both subgroups with and without frailty, CPET measures were significantly associated with mortality risk (peak VO2, peak WR, and VE/VCO2 slope: P < 0.05). The peak VO2 (Δ area under the curve, 0.09; 95% CI, 0.02 to 0.16) or the peak WR (Δ area under the curve, 0.09; 95% CI, 0.02 to 0.15) most significantly improved the prognostic accuracy.

Conclusions

Results showed the fragile aspect of the frailty phenotype in the hemodialysis population and the superior ability of CPET to indicate death risk complementing that aspect.

The Application of Voice Biomarkers in Frailty: A Scoping Review

BACKGROUND

With an increasing prevalence of frailty among older adults, effective classification and management strategies for frailty have become imperative. Voice biomarkers, offering insights into the overall health status of older adults, hold promise for enhancing the management of this multifaceted geriatric syndrome.

OBJECTIVES

This scoping review aims to consolidate existing knowledge regarding the relationship between frailty and voice biomarkers.

METHODS

A systematic search was conducted following the preferred reporting items for systematic reviews and meta-analyses extension for scoping reviews guidelines across multiple databases: PubMed, Embase, Proquest, Scopus, and Web of Science. The results were synthesized through information extraction and are presented in tables.

RESULTS

A total of 11 studies met the inclusion criteria. The majority (63.6%) employed a cross-sectional design. Voice biomarkers encompassed acoustic parameters, such as the peak/average volume ratio, and linguistic parameters, such as verbal fluency. Nine articles reported significant associations between frailty and acoustic parameters. Three articles included linguistic parameters in their analyses. Only one demonstrated associations between frailty and both acoustic and linguistic parameters.

CONCLUSION

Despite the relatively small sample sizes in the included studies, the findings underscore a significant connection between voice biomarkers and frailty among older adults, suggesting the potential utility of vocal characteristics as non-invasive indicators for identifying and managing frailty. Integrating voice biomarkers into routine geriatric assessments could substantially improve the precision and efficiency of frailty management, facilitating personalized healthcare interventions tailored to the needs of older adults.

Oral Frailty as a Risk Factor for Fall Incidents among Community-Dwelling People

BACKGROUND

Identifying older adults with a high risk of falling and providing them with appropriate intervention are vital measures for preventing fall incidents. Scholars report that oral frailty, a decline in oral function, is related to physical function; thus, it bears a potential association with fall risks. This study aimed to investigate the relationship between fall incidents and the status of physical and oral frailty among a sample of residents in Osaka Prefecture.

SUBJECTS AND METHODS

This study targeted community-dwelling people aged 50 years and older who responded to an annual questionnaire survey using a health app for 2 consecutive years, namely, 2020 and 2021. This study analyzed responses from 7591 (62 ± 7 years) participants and determined the status of their oral frailty and comprehensive and physical frailty using the Kihon Checklist.

RESULTS

In the 2020 and 2021 surveys, 17% and 19% of the participants exhibited oral frailty and experienced a fall in the previous year, respectively. Logistic regression analysis demonstrated that oral frailty (adjusted odds ratio: 1.553) and physical frailty as well as low levels of awareness of frailty were significant explanatory variables of the occurrence of fall incidents during the subsequent year.

CONCLUSIONS

Future studies are required to elucidate the mechanisms by which oral frailty induces fall incidents.

Epidemiology and risk factors of oral frailty among older people: an observational study from China

OBJECTIVES

This study aimed to compare the prevalence of oral frailty among community-dwelling older people in Nanjing, China with the usage of different measurements, and to investigate the potential risk factors of oral frailty.

DESIGN

Cross-sectional study.

SETTING AND PARTICIPANTS

A total of 338 community-dwelling older people in Nanjing, China were recruited.

METHODS

Oral frailty was measured based on the Oral Frailty Index-8 (OFI-8) scale and other measurement methods including the number of natural teeth (TN), repetitive saliva-swallowing test (RSST), and oral diadochokinesis (ODK). The chi-square test and the binary logistic regression analysis were performed to identify potential risk factors for oral frailty.

RESULTS

There were 310 participants included in the analysis. Prevalence of oral frailty by using the OFI-8, OFI-8 + TN, OFI-8 + ODK, OFI-8 + TN + ODK and RSST measurement methods were 69.0%, 27.4%, 51.9%, 21.0% and 2.9%, respectively. Passive smoking (OR = 2.04; 95%CI 1.03-4.03), being widowed/unmarried (OR1 = 2.53; 95%CI 1.25-5.10; OR2 = 2.94; 95%CI 1.12-7.77), pre-frailty (OR = 1.76; 95%CI 1.03-3.01), frailty (OR = 3.01; 95%CI 1.39-6.54), and aged 80 years and above (OR = 3.99; 95%CI 1.35-11.81) were found to be risk factors of oral frailty by the usage of the four kinds of measurement methods.

CONCLUSIONS AND IMPLICATIONS

The definition and diagnostic criteria of oral frailty are strongly needed to be unified in future research. Only subjective assessment is not enough for assessing oral frailty. Among objective indicators, RSST is not suitable as a screening method for oral frailty. In addition, objective indicators including TN and ODK should be valued for early screening and preventive interventions. The risk factors of oral frailty include physical frailty, passive smoking, and being widowed.

Association of the number of remaining teeth with kidney function in community-dwelling healthy older adults: a cross-sectional study

Objectives

Although a few studies have investigated the relationship between kidney and oral function (number of remaining teeth), their results remain inconclusive. Therefore, this study aimed to investigate the relationship between kidney function and oral health in community-dwelling healthy elderlies and examine the factors associated with kidney function.

Materials and Methods

We used cross-sectional data from the Shimane prefecture cohort recruited by the Center for Community-Based Health Research and Education in 2019. We collected clinical data on dental status, background factors and kidney function (estimated glomerular filtration rate [eGFR], mL/min/1.73 m2 and creatinine levels, mg/dL).

Results

The study enrolled 481 participants, whose mean age was 66.7±7.4 years, and 223 (46.4%) participants were men. Multivariate analysis revealed significant correlations between eGFR (B=0.17, P=0.04), creatinine (B=-0.54, P<0.01), and the number of remaining teeth. The number of remaining teeth was associated with creatinine and eGFR, which are indicators of kidney function.

Conclusion

This study suggests that preserving the teeth may prevent decline in kidney function. Dental professionals should provide instructions and professional care to reduce the risk of systemic diseases such as kidney dysfunction.

Association between oral hypofunction and general health: a systematic review

BACKGROUND

Oral hypofunction comprises 7 oral function conditions, including mastication, swallowing, pronouncing, oral hygiene, and oral dryness. However, it remains unresolved whether having oral hypofunction and each individual condition adversely affect general health. This study aimed to investigate the association between oral hypofunction and general health, encompassing physical, psychological, and social dimensions.

METHODS

Oral hypofunction was diagnosed following the criteria proposed by the 2016 Japan Society of Gerodontology, comprising 7 oral function conditions. Oral hypofunction was diagnosed when at least 3 conditions presented. The selected studies eligible for reviewing were based on the PI(E)CO criteria: P (population), adult and older adults; I/E (intervention/exposure), having oral hypofunction by considering overall and individual 7 oral function conditions; C (comparator), not having oral hypofunction; O (outcome), the general health status, encompassing physical, psychological, and social dimensions. Electronic search limited to English articles was performed through PubMed, Scopus, and Cochrane Database of Systematic Reviews databases from January 2016 to June 2023. The included studies were assessed for quaility and risk of bias using the modified Newcastle-Ottawa scale. Qualitative analyses were performed on the general outcome, and having oral hypofunction considering overall and individual oral function conditions.

RESULTS

Ten studies were included in the final syntheses. One was a prospective cohort, one was a case-control, and the others were cross-sectional studies. All included studies were high quality. General health outcomes were mostly frailty, sarcopenia, and malnutrition, whereas mild cognitive impairment,social withdrawal, and gastric cancer prognosis were identified in one of the included studies. The association between general health and having oral hypofunction was stronger than when considering an individual condition. The health outcomes were predominantly associated with mastication and swallowing, whereas their relationships with oral hygiene and dryness were less likely to be reported.

CONCLUSIONS

The present review found an association between the presence of oral hypofunction and impaired general health. However, the specific impact on individual physical, psychological, and social dimensions cannot be distinctly delineated. Further prospective studies are required to clarify the causal-effect relationship between oral and general health.

Use of frailty assessment instruments in nephrology populations: a scoping review

BACKGROUND

Frailty is a clinical syndrome of accelerated aging associated with adverse outcomes. Frailty is prevalent among patients with chronic kidney disease but is infrequently assessed in clinical settings, due to lack of consensus regarding frailty definitions and diagnostic tools. This study aimed to review the practice of frailty assessment in nephrology populations and evaluate the context and timing of frailty assessment.

METHODS

The search included published reports of frailty assessment in patients with chronic kidney disease, undergoing dialysis or in receipt of a kidney transplant, published between January 2000 and November 2021. Medline, CINAHL, Embase, PsychINFO, PubMed and Cochrane Library databases were examined. A total of 164 articles were included for review.

RESULTS

We found that studies were most frequently set within developed nations. Overall, 161 studies were frailty assessments conducted as part of an observational study design, and 3 within an interventional study. Studies favoured assessment of participants with chronic kidney disease (CKD) and transplant candidates. A total of 40 different frailty metrics were used. The most frequently utilised tool was the Fried frailty phenotype. Frailty prevalence varied across populations and research settings from 2.8% among participants with CKD to 82% among patients undergoing haemodialysis. Studies of frailty in conservatively managed populations were infrequent (N = 4). We verified that frailty predicts higher rates of adverse patient outcomes. There is sufficient literature to justify future meta-analyses.

CONCLUSIONS

There is increasing recognition of frailty in nephrology populations and the value of assessment in informing prognostication and decision-making during transitions in care. The Fried frailty phenotype is the most frequently utilised assessment, reflecting the feasibility of incorporating objective measures of frailty and vulnerability into nephrology clinical assessment. Further research examining frailty in low and middle income countries as well as first nations people is required. Future work should focus on interventional strategies exploring frailty rehabilitation.

Association between Bone Mineral Density and Oral Frailty on Renal Function: Findings from the Shika Study

The association between oral frailty (OFr) and body action has been investigated, but its association with systemic function remains unclear. Therefore, this cross-sectional study examined the association between OFr with decreased bone mineral density (BMD) and renal function in residents of Shika town, Ishikawa Prefecture, Japan aged ≥40 years. This study included 400 inhabitants. The OFr total score was assessed using three oral domains in the Kihon Checklist (a self-reported comprehensive health checklist), the number of teeth, and brushing frequency per day. Measurements were the estimated glomerular filtration rate (eGFR) and the osteo-sono assessment index (OSI). Using a two-way analysis of covariance (p = 0.002), significantly lower OSI was indicated in the eGFR < 60 and OFr group than in the eGFR of < 60 and non-OFr group after adjusting for age, body mass index, and drinking and smoking status as confounding factors. Multiple logistic regression analysis confirmed this relationship (p = 0.006). Therefore, lower BMD seems to be associated with lower renal function only when accompanied by OFr. Further longitudinal studies are needed to confirm these results.

Relationships between cystatin C and creatinine‐based eGFR with low tongue pressure in Japanese rural community‐dwelling older adults

Background

Sarcopenia is prevalent in patients with chronic kidney disease (CKD), which is defined as a low estimated glomerular filtration rate (eGFR). It has been reported that oral hypofunction characterized by decreased tongue pressure is related to sarcopenia. Although there are several previous reports regarding the association of renal dysfunction with oral hypofunction characterized by low tongue pressure, the association between tongue pressure and renal function is not fully understood.

Methods

This cross‐sectional study included 68 men aged 79.0 ± 4.8 years and 145 women aged 77.3 ± 5.4 years from a rural area in Hyogo Prefecture, Japan. We examined the relationships between cystatin C‐based CKD (CKDcys), creatinine‐based CKD (CKDcre), ratio of cystatin C‐based GFR (eGFRcys) divided by creatinine‐based GFR (eGFRcre): eGFRcys/eGFRcre, and tongue pressure in community‐dwelling older adults.

Results

Tongue pressure was significantly lower in participants with CKDcys than in those without CKDcys in men and women. However, there were no significant differences in tongue pressure with or without CKDcre. Tongue pressure was significantly lower in participants with eGFRcys/eGFRcre <1.0, than in those with eGFRcys/eGFRcre ≧ 1.0 in men. According to the receiver operating characteristic analysis, the optimal cut‐off value of tongue pressure for the presence of CKDcys was 36.6kPa, area under the curve (AUC) 0.74 (specificity 54.8%, sensitivity 84.6%) in men and 31.8kPa, AUC 0.65 (specificity 67.3%, sensitivity 60.5%) in women.

Conclusions

CKDcys but not CKDcre is associated with low tongue pressure. In addition, a lower eGFRcys/eGFRcre ratio is a useful screening marker of low tongue pressure in community‐dwelling older adults.

Association between dry mouth and physical frailty among community-dwelling older adults in Japan: The Otassha Study

OBJECTIVE

To elucidate the relationship between physical frailty and dry mouth among community-dwelling older adults in Japan.

BACKGROUND

Oral hypofunction is associated with physical frailty in older adults. Dry mouth, subjectively evaluated as xerostomia and objectively measured as hyposalivation, is highly prevalent in older adults. However, few reports have used both measures of dry mouth and investigated their association with physical frailty.

MATERIALS AND METHODS

This cross-sectional study included 643 individuals (mean age, 73.9 years) from the Otassha Study in 2019. Xerostomia was assessed using the 5-item Summated Xerostomia Inventory (SXI). Hyposalivation was assessed by measuring the amount of resting saliva using the modified cotton roll method. Frailty phenotypes were defined by weakness, slowness, weight loss, low physical activity level and exhaustion components, and served as the outcome variable. Participants with three or more components were considered physically frail, and those with one or two components were considered pre-frail. Ordinal logistic regression analyses were performed to evaluate the associations between physical frailty and xerostomia and hyposalivation.

RESULTS

Among the participants, 4.5% and 49.8% had physical frailty and pre-frailty, respectively. In ordinal logistic regression analysis adjusted for demographic and health characteristics, the SXI score was associated with physical frailty status (adjusted odds ratio for a one-point increase in SXI, 1.12; 95% confidence interval, 1.06-1.19). However, no difference was observed between the amount of resting saliva and severity of physical frailty.

CONCLUSION

Xerostomia is associated with physical frailty among community-dwelling older adults in Japan.

CLINICAL TRIAL REGISTRATION

Not applicable.

Outcome Analysis Using the Modified Frailty Index-5 in Patients With Complex Aortoiliac Disease

OBJECTIVES

Vascular surgery patients commonly have several comorbidities that cumulatively lead to a frailty status. The cumulative comorbidities disproportionately increase the risk of adverse events and are also associated with worsened long-term prognosis. In recent years, several tools have been elaborated with the objective of quantifying a patient's frailty. One of them is the modified frailty index-5 (mFI-5), a simplified and easy to use index. There is scarce data regarding its value as a prognostic factor in aortoiliac occlusive disease. The aim of this work is to validate mFI-5 as a potential postoperative prognostic indicator in this population.

METHODS

From January 2013 to January 2020, 109 patients who underwent elective revascularizations, either endovascular or open surgery, having Trans-Atlantic Inter-Society Consensus II type D aortoiliac lesions in a tertiary and a regional hospital were selected from a prospective vascular registry. Demographic data was collected including diabetes mellitus, chronic heart failure, chronic obstructive pulmonary disease, arterial hypertension requiring medication and functional status. The 30-d and subsequent long-term surveillance outcomes were also collected including major adverse cardiovascular events (MACE), major adverse limb events (MALE) and all-cause mortality were assessed in the 30-d post-procedure and in the subsequent long-term surveillance period. The mFI-5 was applied to this population to evaluate the prognostic impact of this frailty marker on mortality and morbidity.

RESULTS

In the long-term follow-up, mFI-5 was significantly associated with MACE (hazard ratio [HR] 2.469; 95% confidence interval [CI]: 1.267-4.811; P = .008) and all-cause mortality (HR 2.585; 95% CI: 1.270-5.260; P = .009). However, there was no significant association with 30-day outcomes. Along with the presence of chronic kidney disease, mFI-5 was the prognostic factor better able of predicting MACE. No prognostic value was found regarding short-term outcomes.

CONCLUSION

The mFI-5 index may have a role in predicting long term outcomes, namely MACE and all-cause mortality, in the subset of patients with extensive aortoiliac occlusive disease. Its ease of use can foster its application in risk stratification and contribute for the decision-making process.

Oral function, nutritional status and physical status in Japanese independent older adults

OBJECTIVES

To clarify the associations among oral status, nutritional status and physical status in Japanese independent older adults.

BACKGROUND

It is important to focus on factors affecting physical status associated with life dysfunction, long-term care and mortality. However, there are very few reports of the associations among oral status, nutritional status and physical status.

MATERIALS AND METHODS

Patients who visited the Preventive Dentistry Clinic at Okayama University Hospital from November 2017 to January 2019 participated in this cross-sectional study. Number of teeth, periodontal condition and oral function were recorded. Bacteria counts in tongue dorsum, oral wettability, tongue pressure, tongue and lip movement function [oral diadochokinesis (ODK)], masticatory ability, bite force and swallowing function were measured. Nutritional status was assessed by the Mini Nutritional Assessment. Physical frailty status and Elderly Status Assessment Set were also evaluated. These variables were analysed by structural equation modelling (SEM).

RESULTS

Data from 203 patients were analysed (63 males and 140 females). Patients ranged in age from 60 to 93 years. The final model of the path diagram was completed by SEM. ODK was positively associated with nutritional status, and nutritional status was negatively associated with frailty. Age was associated with ODK, nutritional status and frailty.

CONCLUSION

Based on the associations among age, ODK, nutritional status and frailty, maintaining tongue movement function may contribute to good nutritional status and physical status in Japanese independent older adults.