Interpreting routine biochemistry in those aged over 65 years: a time for change

Cholesterol alone or in combination is associated with frailty among community-dwelling older adults: A cross-sectional study

BACKGROUND

Biological markers contribute to the precise intervention across the continuum of frailty severity. Few studies have explored the advantages of biological markers collected as part of primary care data among community-dwelling older adult population and controversy remains regarding the classic biological markers for frailty.

METHODS

We recruited a total of 8791 adults with a mean age of 71.95 years who met the inclusion and exclusion criteria in Guancheng District and Dalang Town, Dongguan, China. Frailty was assessed by a Chinese frailty evaluation scale. Frailty status was classified with 33-item modified frailty index and latent class analysis was applied to explore the latent classes (subtypes) of frailty. We measured biological markers on blood samples collected. We identify association between specific biological markers or patterns and frailty by logistic regression and association rule mining (ARM) based on the Apriori algorithm.

RESULTS

Multivariable analysis of our data showed that an elevated white blood cell (WBC) count and high cholesterol (CHOL) level were associated with pre-frailty (adjusted odds ratio [aOR] = 1.231, 95 % confidence interval [CI] = 1.009-1.501; aOR = 0.703, 95 % CI = 0.623-0.793) and frailty (aOR = 1.500, 95 % CI = 1.130-1.993; aOR = 0.561, 95 % CI = 0.461-0.684) compared with the normal groups. Importantly, significantly high level of CHOL was associated with a lower risk of four frailty subtypes compared with relatively healthy participants with the most power of association in the multi-frail group (aOR = 0.182, 95 % CI = 0.086-0.386). Based on ARM technique to develop correlation analysis to identify important high-risk clusters among older adult transitions from non-frail to frailty, patterns for normal level of CHOL co-occurred with an elevated creatinine (CREA) level have a significant association with the risk of frailty (aOR = 7.787, 95 % CI = 1.978-30.648) after adjusting for targeted confounders.

CONCLUSIONS

Our study highlights the correlation between classic biological markers, especially CHOL and frailty status and subtypes among community-dwelling older adult, in the primary care setting. Further large-scale prospective studies are still needed to confirm the role of classic biological markers in frailty.

Sarcopenia and Frailty in Heart Failure: Is There a Biomarker Signature?

PURPOSE OF REVIEW

Sarcopenia and frailty are common in patients with heart failure (HF) and are strongly associated with prognosis. This review aims to examine promising biomarkers that can guide physicians in identifying sarcopenia and frailty in HF.

RECENT FINDINGS

Traditional biomarkers including C-reactive protein, aminotransaminase, myostatin, and urinary creatinine as well as novel biomarkers including microRNAs, suppression of tumorigenicity 2 (ST2), galectin-3, and procollagen type III N-terminal peptide may help in predicting the development of sarcopenia and frailty in HF patients. Among those biomarkers, aminotransferase, urinary creatinine, and ST2 predicted the prognosis in HF patients with sarcopenia and frailty. This review outlines the current knowledge of biomarkers that are considered promising for diagnosing sarcopenia and frailty in HF. The listed biomarkers might support the diagnosis, prognosis, and therapeutic decisions for sarcopenia and frailty in HF patients.

Plasma Nickel Levels Correlate with Low Muscular Strength and Renal Function Parameters in Patients with Prostate Cancer

Nickel is associated with cancer in occupational exposure. However, few studies have been devoted to analyzing the effects of nickel at environmental concentrations in cancer patients. In this work, the concentration of nickel in blood samples from patients with prostate cancer (PCa) was evaluated because this metal displays androgenic and estrogenic effects that play a crucial role in prostate carcinogenesis and treatment. We, therefore, compared blood nickel concentration in patients with PCa (non-occupationally exposed) (n = 46) with those in control age-matched individuals (n = 46). We also analyzed if there was any association between sociodemographic factors, clinical variables, geriatric evaluation assessment results, blood cell counts, or biochemical, androgen and estrogen concentrations. Using inductively coupled plasma-mass spectroscopy on the plasma samples, we observed a mean nickel level of 4.97 ± 1.20 µg/L in the PCa group and 3.59 ± 0.49 µg/L in the control group, with a non-significant effect (p = 0.293) between the two groups. The nickel concentration was significantly correlated with patient age (p = 0.005) and reduced handgrip strength (p = 0.003). Regarding biochemical parameters, significant associations were found with the renal glomerular filtration rate (p = 0.024) and blood urea levels (p = 0.016). No significant correlations were observed with other blood analytical parameters or testosterone or estradiol levels. These specific renal function and muscle strength effects were observed at environmental nickel exposure levels believed to be safe or at least far from the high concentrations observed after occupational exposure. Therefore, these parameters deserve further study, given that they could help pinpoint further public health concerns regarding nickel exposure in the general population.

Establishment of gender- and age-specific reference intervals for serum liver function tests among the elderly population in northeast China: a retrospective study

Introduction

Reference intervals (RIs) for younger population may not apply to the elderly population. The aim of this study was to establish gender- and age-specific RIs for serum liver function tests among the elderly population and to compare with younger population RIs currently used in China and other countries.

Materials and methods

This was a retrospective study, and subjects (≥ 18 year-old) were recruited from the laboratory information system (LIS) at the First Hospital of Jilin University between April 2020 and April 2021. The following parameters were collected: aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma-glutamyltransferase (GGT), alkaline phosphatase (ALP), total protein (TP), albumin (ALB), total bilirubin (TBIL), and direct bilirubin (DBIL). The Tukey method was used to eliminate outliers. Reference intervals were established by the nonparametric method.

Results

A total of 23,597 healthy individuals were enrolled in the study. From all parameters AST, ALT, TP and ALB required no gender partition, while ALT, GGT, TP, ALB and DBIL required different partitions for age. Activities and concentrations of ALT, ALB, and TP showed a downward trend in the elderly aged 60-89. In contrast, DBIL showed a gradual upward trend.

Conclusion

The RIs for liver function tests among healthy elderly population were different from those among young population in China. There were apparent gender and age differences in the RIs of liver function for elderly and significant differences compared with national standards and RIs in other countries. Therefore, it is necessary to establish gender- and age-specific RIs for serum liver function tests among the elderly population.

Nursing home residents with suspected urinary tract infections: a diagnostic accuracy study

Background

Urinary tract infections (UTIs) are one of the most common infections in nursing homes (NHs). A high error rate of a UTI diagnosis based solely on clinical criteria is to be expected in older persons as they often present infections in an atypical way. A study was set up to assess the diagnostic value of signs/symptoms and urine dipstick testing in identifying UTIs in NH residents and to explore whether C-reactive protein (CRP) measured by point-of-care testing (POCT) can help in the diagnosis.

Methods

During a three month prospective multicentre study, urine sampling for culture, POCT CRP and urinary dipstick testing were performed in each NH resident with a suspected UTI. UTIs were defined according to Stone et al., i.e. criteria based upon the presence of a set of signs/symptoms and a positive urine culture.

Results

Eleven NHs and 1 263 residents participated. Sixteen out of 137 recorded UTI suspicions were confirmed. Acute dysuria (positive likelihood ratio (LR +): 7.56, 95% confidence interval (CI): 3.94–14.5) and acute suprapubic pain (LR + : 11.4, 95% CI: 3.58–35.9) were found to be significant predictors. The combined nitrite and leucocyte esterase urine dipstick test (one or both positive) had a 96.0% negative predictive value (95% CI: 80.5–99.3%). The sensitivity of a positive CRP test (≥ 5 mg/L) was 60.0% (95% CI: 32.3–83.7%). Antimicrobials were prescribed in 60.2% of suspected but unconfirmed UTIs and in 92.3% of confirmed UTIs.

Conclusions

Using a stringent definition, only 11.7% of our suspicions were confirmed. Besides acute dysuria and suprapubic pain, we were not able to prove that any other clinical sign/symptom or POCT CPR adds useful information to the UTI diagnosis. We confirmed the findings of earlier research that urine dipstick tests are useful in ruling out UTIs and identified a potential overuse of antimicrobials in our NH population.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-022-02866-2.

Hyponatremia in the frail

As the lifespan increases, special attention has been given to the supportive care needs of the elderly. Frailty is an important issue in third age, since it is related to poor quality of life and mortality. The prevalence of pathological conditions related to sodium levels, specifically hyponatremia, is also present in the elderly. Yet, it is unclear, if hyponatremia and frailty are related to each other. This review summarizes the current state of knowledge regarding hyponatremia and frailty and analyzes five independent studies which searched for an association between those two parameters. As indicated by this study results, hyponatremia consists a risk factor for frailty. This could be explained by an effect of hyponatremia on sarcopenia and on cognitive function, which consist components of frailty. Thus, it is essential to monitor sodium levels in the elderly and to develop related interventions (e.g. using arginine vasopressin antagonists) in order to prevent frailty.

Dysnatremia in Relation to Frailty and Age in Community-dwelling Adults in the National Health and Nutrition Examination Survey

Background

Frailty represents an age-related state of increased risk of adverse health outcomes, reflecting some combination of increased damage and compromised repair processes. Our objectives were to establish whether frailty is associated with dysnatremia (a deviation of serum sodium from normal values), to determine whether frailty explains the previously established association between age and dysnatremia and to assay the impact of each on mortality.

Methods

The relationship between age, frailty, and dysnatremia was investigated across the adult life course in 8,911 respondents from the 2003-2004 and 2005-2006 cross-sectional National Health and Nutrition Examination Survey, on whom both laboratory and mortality data were available. A frailty index (FI) was calculated for each respondent and related to dysnatremia (serum sodium values outside a 136-144 mmol/L reference range).

Results

Dysnatremia was significantly related to both age and frailty; as the degree of frailty increased, so did the proportion with dysnatremia, for example, from 4.1% in those with FI less than 0.10, to 12.4% in those with FI 0.40 or more; p less than .001. Adjusted for frailty, the relationship between age and dysnatremia was no longer significant. In the age- and sex-adjusted Cox models, both frailty (hazard ratio [HR]: 1.05; 95% confidence interval [CI]: 1.04-1.05 for every 0.01 increase in FI) and dysnatremia (HR: 1.85; 95% CI: 1.51-2.26) were significant predictors of mortality; when hyponatremia was separated from hypernatremia in the Cox models, hypernatremia wasn't significant, but only 41 participants were identified as hypernatremic.

Conclusion

Increasing frailty is associated with dysnatremia and confounds the association between age and dysnatremia.

C-Reactive Protein and Frailty in the Elderly: A Literature Review

Chronic inflammation is a well-established background process in many age-related diseases. Many recent studies investigate the use of various inflammatory biomarkers such as C-reactive protein (CRP), interleukin-6, and interleukin-1 as predictors of physical and cognitive performance among elders. The phenotype of frailty has also been associated with underlying inflammatory mechanisms. The aim of this article was to review the literature referring to the correlation of CRP serum levels and frailty in older individuals. We tried to identify all relevant publications regarding the relation of CRP as an index of frailty in the elderly and its potential use. Although many studies in the recent medical literature positively associate serum CRP levels and frailty in older individuals, some do not, and some raise some interesting questions and set the basis for future studies. The association of CRP and frailty in elder patients should be considered when clinicians interpret inflammatory biomarkers in various clinical settings in such patients. Well-designed, prospective clinical trials are warranted to better assess the role and pathophysiology of frailty in the elderly and its mechanisms as also the exact role of CRP as an inflammatory marker and as a prognostic index in this syndrome.

A Cross-Sectional Study of Ageing and Cardiovascular Function over the Baboon Lifespan

Background

Ageing is associated with changes at the molecular and cellular level that can alter cardiovascular function and ultimately lead to disease. The baboon is an ideal model for studying ageing due to the similarities in genetic, anatomical, physiological and biochemical characteristics with humans. The aim of this cross-sectional study was to investigate the changes in cardiovascular profile of baboons over the course of their lifespan.

Methods

Data were collected from 109 healthy baboons (Papio hamadryas) at the Australian National Baboon Colony. A linear regression model, adjusting for sex, was used to analyse the association between age and markers of ageing with P < 0.01 considered significant.

Results

Male (n = 49, 1.5–28.5 years) and female (n = 60, 1.8–24.6 years) baboons were included in the study. Age was significantly correlated with systolic (R² = 0.23, P < 0.001) and diastolic blood pressure (R² = 0.44, P < 0.001), with blood pressure increasing with age. Age was also highly correlated with core augmentation index (R² = 0.17, P < 0.001) and core pulse pressure (R² = 0.30, P < 0.001). Creatinine and urea were significantly higher in older animals compared to young animals (P < 0.001 for both). Older animals (>12 years) had significantly shorter telomeres when compared to younger (<3 years) baboons (P = 0.001).

Conclusion

This study is the first to demonstrate that cardiovascular function alters with age in the baboon. This research identifies similarities within cardiovascular parameters between humans and baboon even though the length of life differs between the two species.

Serum Biochemical Phenotypes in the Domestic Dog

The serum or plasma biochemical profile is essential in the diagnosis and monitoring of systemic disease in veterinary medicine, but current reference intervals typically take no account of breed-specific differences. Breed-specific hematological phenotypes have been documented in the domestic dog, but little has been published on serum biochemical phenotypes in this species. Serum biochemical profiles of dogs in which all measurements fell within the existing reference intervals were retrieved from a large veterinary database. Serum biochemical profiles from 3045 dogs were retrieved, of which 1495 had an accompanying normal glucose concentration. Sixty pure breeds plus a mixed breed control group were represented by at least 10 individuals. All analytes, except for sodium, chloride and glucose, showed variation with age. Total protein, globulin, potassium, chloride, creatinine, cholesterol, total bilirubin, ALT, CK, amylase, and lipase varied between sexes. Neutering status significantly impacted all analytes except albumin, sodium, calcium, urea, and glucose. Principal component analysis of serum biochemical data revealed 36 pure breeds with distinctive phenotypes. Furthermore, comparative analysis identified 23 breeds with significant differences from the mixed breed group in all biochemical analytes except urea and glucose. Eighteen breeds were identified by both principal component and comparative analysis. Tentative reference intervals were generated for breeds with a distinctive phenotype identified by comparative analysis and represented by at least 120 individuals. This is the first large-scale analysis of breed-specific serum biochemical phenotypes in the domestic dog and highlights potential genetic components of biochemical traits in this species.

Approach to Hyponatremia in Congestive Heart Failure: A Survey of Canadian Specialist Physicians and Trainees

Background

Hyponatremia is a recognized complication of congestive heart failure (CHF) and is associated with reduced survival. Therefore, early identification and appropriate management of hyponatremia is important. The aim of this study was to determine the general approach amongst Canadian healthcare practitioners and trainees to the identification and management of hyponatremia complicating CHF.

Methods

Respondents completed 15 multiple-choice style questions in 3 case scenarios regarding the approach to management of hyponatremia complicating CHF using an online survey on UKidney.com between November 2012 and May 2013. Results were presented as a proportion of averaged correct/incorrect responses amongst Canadian nephrologists, cardiologists, internists and trainees in each of two domains; pathophysiology and management. Management was further subdivided into correct and incorrect use of diuretic therapy, hypertonic saline, oral urea tablets, vasopressin receptor antagonists (vaptans) and rate of sodium correction. Correct responses were determined by an expert panel of Canadian nephrologists and cardiologists based on review of evidence informed guidelines and current recommendations.

Results

There were 1757 responses to our online survey amongst 455 Canadian respondents, 1139 of which were from cardiologists, nephrologists, general internists, or trainees. Overall, the pathophysiology governing hyponatremia in CHF was correctly identified 68.7 % of the time (n = 380 responses, averaged over 4 questions). Hyponatremia was managed inappropriately 43.6 % of the time, with trainees scoring best overall with correct responses 60.3 % of the time (n = 759 responses, over 11 questions). Importantly, an incorrect rate for sodium correction was selected 61.1 % of the time overall, (n = 211 responses, averaged over 3 questions).

Conclusions

This study identified that there are differences in the understanding of pathophysiology and management strategies for hyponatremia in the context of CHF amongst Canadian specialist physicians and trainees. A more consistent approach to hyponatremia is required and might best be achieved through formal knowledge translation.

Electronic supplementary material

The online version of this article (doi:10.1186/s40697-016-0094-9) contains supplementary material, which is available to authorized users.

Serum albumin and muscle measures in a cohort of healthy young and old participants

Consensus on clinically valid diagnostic criteria for sarcopenia requires a systematical assessment of the association of its candidate measures of muscle mass, muscle strength, and physical performance on one side and muscle-related clinical parameters on the other side. In this study, we systematically assessed associations between serum albumin as a muscle-related parameter and muscle measures in 172 healthy young (aged 18-30 years) and 271 old participants (aged 69-81 year) from the European MYOAGE study. Muscle measures included relative muscle mass, i.e., total- and appendicular lean mass (ALM) percentage, absolute muscle mass, i.e., ALM/height(2) and total lean mass in kilograms, handgrip strength, and walking speed. Muscle measures were standardized and analyzed in multivariate linear regression models, stratified by age. Adjustment models included age, body composition, C-reactive protein and lifestyle factors. In young participants, serum albumin was positively associated with lean mass percentage (p = 0.007) and with ALM percentage (p = 0.001). In old participants, serum albumin was not associated with any of the muscle measures. In conclusion, the association between serum albumin and muscle measures was only found in healthy young participants and the strongest for measures of relative muscle mass.

The frailty syndrome: a comprehensive review

The frailty syndrome is defined as unintentional weight and muscle loss, exhaustion, and declines in grip strength, gait speed, and activity. Evidence with respect to the clinical definition, epidemiology, mechanisms, interactions, assessment, prevention, and treatment of frailty in the older adult is reviewed.