No strong correlations between serum cytokine levels, CMV serostatus and hand-grip strength in older subjects in the Berlin BASE-II cohort

Self-reported and accelerometer-based assessment of physical activity in older adults: results from the Berlin Aging Study II

Physical activity (PA) has a substantial impact on health and mortality. Besides questionnaires that rely on subjective assessment of activity levels, accelerometers can help to objectify an individual's PA. In this study, variables estimating PA and sleep time obtained through the wGT3X-BT activity monitor (ActiGraph LLC, USA) in 797 participants of the Berlin Aging Study II (BASE-II) were analyzed. Self-reports of PA and sleep time were recorded with Rapid Assessment of Physical Activity (RAPA) and the Pittsburgh Sleep Quality Index sleep questionnaire (PSQI). Total cholesterol (TC), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), triglycerides (TG), fasting glucose, and hemoglobin A1c (HbA1c) were determined in an accredited standard laboratory. Of all participants, 760 fulfilled the PA wear-time criteria. In this sample mean age was 75.6 years (SD: 3.8 years, range 66.0-94.1 years) and 53% of the included participants were women. Average wear time was 23.2 h/day (SD 1.3 h/day). Statistically significant differences between RAPA groups were found for all accelerometric variables except energy expenditure. Post-hoc analysis, however, suggested low agreement between subjective and device-based assessment of physical activity. TC, HDL-C, LDL-C, TG, fasting glucose and HbA1c were weakly correlated with accelerometric variables (Pearson's r ≤ 0.25). Device-based average sleep time per night (mean sleep time = 6.91 h, SD = 1.3, n = 720) and self-reported average sleep time per night (mean sleep time = 7.1 h, SD = 1.15 h, n = 410) were in a comparable range and moderately correlated (Pearson's r = 0.31, p < 0.001, n = 410). Results from this study suggest that self-reported PA obtained through the RAPA and device-based measures assessed by accelerometers are partially inconsistent in terms of the physical activity level of the participants. Self-reported and device-based measures of average sleep time per night, however, were comparable.

C-reactive protein, but not neutrophil-lymphocyte ratio, is inversely associated with muscle strength only in older men: NHANES 1999-2002

To evaluate the association of inflammation (C-reactive protein (CRP) and neutrophil-lymphocyte ratio (NLR) levels) with muscle strength in older adults. We also aimed to evaluate whether these associations are sex-specific. A cross-sectional study was performed with data from the National Health and Nutrition Examination Survey (NHANES) 1999-2000 and 2001-2002. A total of 2387 individuals over 50 years of both sexes were evaluated, according to the eligibility criteria for the strength test. Muscle strength was measured by Kinetic Communicator isokinetic dynamometer; while the NLR was obtained by the ratio of the total neutrophil for lymphocyte count and CRP was quantified by latex nephelometry. Linear regression analyses, crude and adjusted for confounders, were used to estimate the coefficients and 95 % confidence intervals for peak strength (muscle strength) by tertiles of NLR and CRP. There was no association between NLR and peak strength for both sexes. CRP levels were inversely associated with peak force in men [2nd tertile β = -3.33 (-15.92; 9.25); 3rd tertile β = -24.69 (-41.18; -8.20), p for trend = 0.005], but not in women [2nd tertile β = -3.22 (-15.00; 8.56); 3rd tertile β = -9.23 (-28.40; -9.94), p for trend = 0.332]. In conclusion, NLR levels were not associated with muscle strength in both sexes. CRP levels were inversely associated with muscle strength in older men, but not in women, suggesting that the association between inflammation and muscle strength in older adults can be sex-specific.

Cardiovascular Inflammaging: Mechanisms and Translational Aspects

Aging is one of the major non-reversible risk factors for several chronic diseases, including cancer, type 2 diabetes, dementia, and cardiovascular diseases (CVD), and it is a key cause of multimorbidity, disability, and frailty (decreased physical activity, fatigue, and weight loss). The underlying cellular mechanisms are complex and consist of multifactorial processes, such as telomere shortening, chronic low-grade inflammation, oxidative stress, mitochondrial dysfunction, accumulation of senescent cells, and reduced autophagy. In this review, we focused on the molecular mechanisms and translational aspects of cardiovascular aging-related inflammation, i.e., inflammaging.

Inflammatory marker trajectories associated with frailty and ageing in a 20‐year longitudinal study

Objective

The aim of this exploratory study was to investigate the development of low‐grade inflammation during ageing and its relationship with frailty.

Methods

The trajectories of 18 inflammatory markers measured in blood samples, collected at 5‐year intervals over a period of 20 years from 144 individuals aged 65–75 years at the study endpoint, were related to the degree of frailty later in life.

Results

IFN‐γ‐related markers and platelet activation markers were found to change in synchrony. Chronically elevated levels of IL‐6 pathway markers, such as CRP and sIL‐6R, were associated with more frailty, poorer lung function and reduced physical strength. Being overweight was a possible driver of these associations. More and stronger associations were detected in women, such as a relation between increasing sCD14 levels and frailty, indicating a possible role for monocyte overactivation. Multivariate prediction of frailty confirmed the main results, but predictive accuracy was low.

Conclusion

In summary, we documented temporal changes in and between inflammatory markers in an ageing population over a period of 20 years, and related these to clinically relevant health outcomes.

Cytomegalovirus Infection and Its Relationship with Leukocyte Telomere Length: A Cross-Sectional Study

Background

Telomeres undergo shortening with each cell division, which could be accelerated by infection. The association between virus infection and telomere length is poorly understood. In the present study, we investigated the putative associations between leukocyte telomere length (TL), cytomegalovirus (CMV) infection, and C-reactive protein (CRP) in a national representative sample of noninstitutionalized population.

Methods

We analyzed data that was collected in a cross-sectional setting, where 3,987 participants were enrolled with available data on telomere length. The association between telomere length with previous CMV infection and CRP was analyzed using multivariable linear regression models. We further tested if obesity, measured by body mass index (BMI), and smoking could modify this relationship.

Results

In total, around 46% percent of the study population were men and 54% were women. Average ages were 35.1 years for men and 35.0 years for women. One unit increase of CMV antibody IgG titer was associated with -0.07 (95% confidence interval: -0.12, -0.01) unit decrease of leukocyte TL when sex was adjusted for. After additionally adjusting for BMI and smoking status, the magnitude of the association was only slightly decreased to -0.06 (95% confidence interval: -0.11, -0.01). The effect sizes were comparable after additionally adjusting for CRP. These analyses imply that previous CMV infection affects leukocyte TL through pathways other than CRP.

Conclusions

Previous CMV infection was associated with shorter leukocyte TL. This association was independent of CRP.

Low muscle strength and increased arterial stiffness go hand in hand

Low handgrip strength and increased arterial stiffness are both associated with poor health outcomes, but evidence on the relationship between handgrip strength and arterial stiffness is limited. In this cross-sectional analysis of combined baseline datasets from the LipidCardio and Berlin Aging Study II cohorts we aimed to examine whether handgrip strength (HGS) is associated with arterial stiffness. 1511 participants with a median age of 68.56 (IQR 63.13–73.08) years were included. Arterial stiffness was assessed by aortal pulse wave velocity (PWV) with the Mobil-O-Graph device. Handgrip strength was assessed with a handheld dynamometer.

The mean HGS was 39.05 ± 9.07 kg in men and 26.20 ± 7.47 kg in women. According to multivariable linear regression analysis per 5 kg decrease in handgrip strength there was a mean increase in PWV of 0.08 m/s after adjustment for the confounders age, sex, coronary artery disease, systolic blood pressure, body mass index, cohort, and smoking. Thus, there was evidence that low handgrip strength and increased arterial stiffness go hand in hand. Arterial stiffness can possibly create the missing link between low handgrip strength and increased cardiovascular morbidity and mortality. Causality and direction of causality remain to be determined.

T cell phenotypes associated with insulin resistance: results from the Berlin Aging Study II

Background

Obesity is associated with chronic low-grade inflammation leading to metabolic and cardiovascular diseases, but a subset of obese individuals is considered insulin sensitive (IS). The underlying pathophysiologic mechanisms remain elusive and clinical studies on the relationship between inflammatory markers and metabolically healthy obesity (MHO) are scarce.

Methods

In this cross-sectional analysis, we included a sample of 437 older participants (60–84 years) from the Berlin Aging Study II (BASE-II). Peripheral blood mononuclear cells were isolated, immune cell subsets were analyzed with multiparameter flow cytometry and systemic cytokine levels were measured. Immune cell parameters were correlated with metabolic measures and multiple linear regression analysis was conducted and adjusted for various demographic and clinical factors.

Results

We found that frequencies of naïve and memory CD4⁺ and CD8⁺ T cells inversely correlated with measures for insulin sensitivity in the older population. Moreover, the percentages of naïve CD4⁺ and CD8⁺ T cells were significantly higher, whereas activated T cells and IL-6 levels were lower in IS compared to insulin resistant (IR) obese individuals. The percentages of naïve CD4⁺ and CD8⁺ T cells were predictive for impaired insulin sensitivity (ß = 0.16, p = 0.01 and ß = 0.11, p = 0.04), and the association of naïve CD4⁺ T cells with insulin sensitivity persisted after multivariate adjustment (ß = 0.14, p = 0.02).

Conclusions

These findings support the hypothesis that parameters of systemic inflammation can differentiate IS from IR obese individuals that are at higher risk for cardiometabolic diseases and may have clinical implications with regard to obesity treatment stratification.

Trial registration

DRKS00009277. Registered 31 August 2015 - Retrospectively registered.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12979-020-00211-y.

Circulating Interleukin-6 (but Not Other Immune Mediators) Associates with Criteria for Fried's Frailty among Very Old Adults

Methods

One hundred and sixty-one very old patients (aged ≥80 years) devoid of cognitive decline were eligible for analyses. Clinical and biochemical data along with physical and cognitive assessments encompassing dual-energy X-ray scans and hand dynamometry were adopted to investigate frailty criteria, while circulating immune mediators (IFNγ, IL-2, IL-4, IL-6, IL-10, and TNFα) were assessed using high-throughput flow cytometry.

Results

Preliminarily, IL-6 correlated positively with waist-to-hip ratio and C-reactive protein and negatively with glycemia. In analyses controlled for these factors, serum levels of IL-6 were comparatively augmented among the very old participants with reduced grip strength (OR = 3.299; 95% CI 1.08–6.09; p=0.032) and among those with slow walk speed (OR = 2.460; 95% CI 1.16–7.05; p=0.022).

Conclusions

Our study shows a strong negative correlation of IL-6 levels with Fried's frailty components of grip strength and walk speed in very old adults, regardless of confounding factors.

Immunosenescence profiles are not associated with muscle strength, physical performance and sarcopenia risk in very old adults: The Newcastle 85+ Study

Decline in immune system function (immunosenescence) has been implicated in several age-related disorders. However, little is known about whether alteration in T-cell senescence, a process underlying immunological ageing, is related to muscle health in very old adults (aged ≥85 years). Utilising data from the Newcastle 85+ Study, we aimed to (a) derive and characterise immunosenescence profiles by clustering 13 baseline immunosenescence-related biomarkers of lymphocyte compartments in 657 participants; (b) explore the association between the profiles and 5-year change in muscle strength (grip strength) and physical performance (Timed Up-and-Go test), and (c) determine whether immunosenescence profiles predict 3-year incident sarcopenia. Two distinct clusters were identified; Cluster 1 ('Senescent-like phenotype', n = 421), and Cluster 2 ('Less senescent-like phenotype', n = 236) in individuals with complete biomarker data. Although Cluster 1 was characterised by T-cell senescence (e.g., higher frequency of CD4 and CD8 senescence-like effector memory cells), and elements of the immune risk profile (lower CD4/CD8 ratio, CMV+), it was not associated with change in muscle function over time, or with prevalent or incident sarcopenia. Future studies will determine whether more in-depth characterisation or change in T-cell phenotypes predict the decline in muscle health in late adulthood.

Telomere length and frailty in older adults-A systematic review and meta-analysis

Telomere shortening has been proposed as a potentially useful biomarker of human ageing and age-related morbidity and mortality. We performed a systematic review and meta-analysis to summarize results from individual studies on the telomere length according to the frailty status and frailty index in older adults. We searched the PubMed, SCOPUS and Web of Science databases to identify studies that evaluated the telomere length in frail and non-frail older adults and the relationship between telomere length and frailty index score. We used the base pairs (bp) as a measure of the telomere length. Summary estimates were calculated using random-effects models. Nine studies were included in the present systematic review and a total of 10,079 older adults were analyzed. We found that the frail older adults (n = 355) had shorter telomeres than the non-frail (n = 1894) (Standardized Mean Difference [SMD] -0.41; 95% CI -0.73 to -0.09; P = 0.01; I² = 82%). Significant differences in telomere length between frail and non-frail older adults were identified in Hispanic (SMD -1.31; 95% CI -1.71 to -0.92; P < 0.0001; I² = 0%) but not in Non-Hispanic countries (SMD -0.13; 95% CI -0.26 to 0.00; P = 0.06; I² = 0%). Similar results were found in the adjusted meta-analysis (SMD -0.56; 95% -1.12 to 0.00; P = 0.05; I² = 85%). A significant but weak relationship was found between telomere length and frailty index analyzing 8244 individuals (SMD -0.06; 95% IC -0.10 to 0.01; P = 0.01; I² = 0%). The current available evidence suggests that telomere length may be not a meaningful biomarker for frailty. Because the potential influence of ethnicity in shortening of telomeres and decline in physiologic reserves associated with aging, additional multiethnic studies are needed.

The Modulatory Effect of Gender and Cytomegalovirus-Seropositivity on Circulating Inflammatory Factors and Cognitive Performance in Elderly Individuals

Aging is characterized by a chronic increase in the systemic levels of inflammatory cytokines even in ostensibly healthy individuals. The drivers of age-related increase in systemic inflammation are unclear but one potential contributor may be a persistent infection with Cytomegalovirus (CMV). In this study, we characterized the inflammatory status of 161 older participants recruited to undergo a six-month training intervention. We investigated the influence of gender and CMV-seropositivity on the main inflammatory and anti-inflammatory circulating biomarkers, such as cytokines, receptor antagonist, soluble receptor, immune cells, and relevant metabolic markers. We found that both gender and CMV-seropositivity modulate circulating peripheral biomarkers, and that CMV-infection modifies associations among the latter. Moreover, we observed an interaction between CMV-serostatus and gender associations with cognitive abilities: gender differences in fluid intelligence (Gf) and working memory (WM) were noted only in CMV-negative individuals. Finally, we found that in the CMV-seronegative participants Gf, episodic memory (EM), and WM correlated negatively with pro-inflammatory tumor necrosis factor (TNF); and EM correlated positively with anti-inflammatory interleukin (IL)-10. In CMV-seropositive individuals EM and Gf correlated negatively with pro-inflammatory IL-6, while EM, Gf, and WM correlated negatively with anti-inflammatory IL-1RA. We conclude that both CMV-serostatus and gender may modulate neuroimmune factors, cognitive performance and the relationship between the two domains and should therefore be considered in comparative and interventional studies with elderly people.

Inflammageing: chronic inflammation in ageing, cardiovascular disease, and frailty

Most older individuals develop inflammageing, a condition characterized by elevated levels of blood inflammatory markers that carries high susceptibility to chronic morbidity, disability, frailty, and premature death. Potential mechanisms of inflammageing include genetic susceptibility, central obesity, increased gut permeability, changes to microbiota composition, cellular senescence, NLRP3 inflammasome activation, oxidative stress caused by dysfunctional mitochondria, immune cell dysregulation, and chronic infections. Inflammageing is a risk factor for cardiovascular diseases (CVDs), and clinical trials suggest that this association is causal. Inflammageing is also a risk factor for chronic kidney disease, diabetes mellitus, cancer, depression, dementia, and sarcopenia, but whether modulating inflammation beneficially affects the clinical course of non-CVD health problems is controversial. This uncertainty is an important issue to address because older patients with CVD are often affected by multimorbidity and frailty - which affect clinical manifestations, prognosis, and response to treatment - and are associated with inflammation by mechanisms similar to those in CVD. The hypothesis that inflammation affects CVD, multimorbidity, and frailty by inhibiting growth factors, increasing catabolism, and interfering with homeostatic signalling is supported by mechanistic studies but requires confirmation in humans. Whether early modulation of inflammageing prevents or delays the onset of cardiovascular frailty should be tested in clinical trials.

Herpes zoster in frail elderly patients: prevalence, impact, management, and preventive strategies

Population aging is a worldwide phenomenon with significant and manifold impacts on society. Advanced age correlates with the onset of frailty. In this vulnerable state, the immune response is weakened and a higher susceptibility to infectious diseases is observed. The present narrative review aims to cover the topic of herpes zoster (HZ) and its complications in frail populations. The lifetime risk of developing HZ is estimated at about 20-30%, and the risk increases with age. In older people, HZ can lead to the inability to recover the lifestyle, the interests, and the level of activity that existed before its development. Severity of the disease at presentation and depression are the major correlates of pain burden in patients with acute HZ and postherpetic neuralgia (PHN). The frail elderly need careful assessment prior to treatment initiation and could be affected to a greater extent by treatment-related adverse events. In light of the significant burden caused by HZ and its complications in the frail elderly, the adoption of a preventive strategy appears to be promising, particularly using vaccination in appropriate age- and risk-groups. Although very few vaccine studies consider explicitly the frail elderly as their study population, there is evidence that the live, attenuated vaccine induces significant immunological responses. An adjuvanted recombinant subunit vaccine has recently been approved in Canada, in the United States, in the European Union, and in Japan, and will likely provide additional opportunities for prevention.

Assessing inflammageing

PURPOSE OF REVIEW

Immunosenescence has been scrutinized in detail, and evidence that inflammation and ageing are interrelated is consistent. Still, a gold standard for assessing the biological age of the immune function in an individual patient is lacking, so that immunosenescence is still not a quantifiable criterion in clinical decision-making processes.

RECENT FINDINGS

This review highlights recent (partly ongoing) studies into biomarkers of inflammation to assess immunosenescence, including large-scale studies, and quotes expert opinion statements. Markers of basal inflammation frequently used include interleukin-6, tumor necrosis factor-α and receptors p55 and p75, C-reactive protein and cytomegalovirus antibody levels. Some cellular markers are particularly advocated to reflect age-related decay of specific immunity, namely the decrease of naive T cells, especially CD8cells, and accumulations of memory T cells, especially late-stage differentiated CD8 cells; the loss of CD28 on lymphocytes is also taken as a biomarker of immunosenescence.

SUMMARY

Substantial progress has been made in both understanding and phenotyping immunosenescence and inflammageing. The diagnosis of the degree of immunosenescence in the individual patient, however, has not yet been standardized.

Telomere Shortening, Inflammatory Cytokines, and Anti-Cytomegalovirus Antibody Follow Distinct Age-Associated Trajectories in Humans

A number of biological parameters have been cited as hallmarks of immune aging. However, it is not clear whether these multiple biological changes are the result of common underlying aging processes and follow correlated trajectories, or whether the patterns of change for multiple parameters vary across individuals and reflect heterogeneity in the aging process. Here, we have studied parameters of immune system aging through longitudinal analysis of telomere length, inflammatory cytokines, and antibody titer to cytomegalovirus (CMV) in 465 subjects ranging in age from 21 to 88 years at the first visit, with an average of 13 years (7-19 years) follow-up. We observed a highly variable rate of change in telomere length of PBMCs with a relatively slow average rate of telomere shortening (-16 bp/year). Similarly, there were significant increases with age in vivo in three inflammation-related cytokines (interferon gamma, IL-6, and IL-10) and in anti-CMV IgG titer, which varied widely across individuals as well. We further observed positive correlative changes among different inflammatory cytokines. However, we did not find significant correlations among the rate of changes in telomere length, inflammatory cytokines, and anti-CMV IgG titers. Our findings thus reveal that age-related trajectories of telomere attrition, elevated circulating inflammatory cytokines, and anti-CMV IgG are independent and that aging individuals do not show a uniform pattern of change in these variables. Immune aging processes are complex and vary across individuals, and the use of multiple biomarkers is essential to evaluation of biological aging of the immune system.

Recent advances in CMV tropism, latency, and diagnosis during aging

Human cytomegalovirus (CMV) is one of the largest viruses known to cause human diseases. Chronic CMV infection, as defined by anti-CMV IgG serology, increases with age and is highly prevalent in older adults. It has complex biology with significant immunologic and health consequences. This article aims to summarize research findings presented at the 6th International Workshop on CMV and Immunosenescence that relate to advances in the areas of CMV tropism, latency, CMV manipulation of cell metabolism, and T cell memory inflation, as well as novel diagnostic evaluation and translational research of chronic CMV infection in older adults. Information summarized here represents the current state of knowledge in these important fields. Investigators have also identified a number of areas that deserve further and more in-depth investigation, including building more precise parallels between mouse CMV (mCMV) and human CMV (HCMV) research. It is hoped that this article will also stimulate engaging discussion on strategies and direction to advance the science to the next level.

Telomere Length Is Not Related to Established Cardiovascular Risk Factors but Does Correlate with Red and White Blood Cell Counts in a German Blood Donor Population

Telomere length (TL) is considered a marker of biological aging and has been associated with the presence of various coronary risk factors in patients. Much less is known about the relationships between TL and classic coronary risk factors in other populations. We measured TL in peripheral blood leukocytes of 343 middle-aged blood donors (mean age 40.2 ± 12.4 years; 201 men, 142 women) using quantitative polymerase chain reaction. Median TL was 0.86 (range: 0.48–1.85) relative TL units. In linear regression analyses with natural log-transformed T to S ratio as the dependent variable, there was a significant association with age (per year: beta = -0.007, p<0.001) and sex (males vs. females: beta = 0.075, p = 0.007) with longer telomeres in men. After adjusting for these two variables, we observed no association of TL with classic coronary risk factors including cholesterol (p = 0.36), triglyceride (p = 0.09), HDL-cholesterol (p = 0.26), LDL-cholesterol (p = 0.36), smoking (p = 0.97), and personal (p = 0.46) or family history (p = 0.63) of cardiovascular disease. However, we did find a significant positive association with white (p = 0.011) and red blood cell count (p = 0.031), hemoglobin (p = 0.014) and hematocrit (p = 0.013); we also found a borderline positive association with thrombocytes (p = 0.074). Positive associations remained significant for hemoglobin (p = 0.017), hematocrit (p = 0.023), and leukocytes (p = 0.009) in a subgroup with no reported vascular disease; associations were of borderline significance for erythrocytes (p = 0.053) and thrombocytes (p = 0.088) in this subgroup. The data do not support the concept that classic coronary risk factors contribute to telomere attrition in a blood donor population. However, telomere attrition may be a marker for reduced proliferation reserve in hematopoietic progenitor cells.