Interleukin-6 plasma levels and socioeconomic status in Brazilian elderly community-dwelling women

Creating and validating a DNA methylation-based proxy for interleukin-6

Background

Studies evaluating the relationship between chronic inflammation and cognitive functioning have produced heterogeneous results. A potential reason for this is the variability of inflammatory mediators which could lead to misclassifications of individuals’ persisting levels of inflammation. DNA methylation (DNAm) has shown utility in indexing environmental exposures and could be leveraged to provide proxy signatures of chronic inflammation.

Method

We conducted an elastic net regression of interleukin-6 (IL-6) in a cohort of 875 older adults (Lothian Birth Cohort 1936; mean age: 70 years) to develop a DNAm-based predictor. The predictor was tested in an independent cohort (Generation Scotland; N = 7028 [417 with measured IL-6], mean age: 51 years).

Results

A weighted score from 35 CpG sites optimally predicted IL-6 in the independent test set (Generation Scotland; R² = 4.4%, p = 2.1 × 10⁻⁵). In the independent test cohort, both measured IL-6 and the DNAm proxy increased with age (serum IL-6: n = 417, β = 0.02, SE = 0.004, p = 1.3 × 10⁻⁷; DNAm IL-6 score: N = 7028, β = 0.02, SE = 0.0009, p < 2 × 10⁻¹⁶). Serum IL-6 did not associate with cognitive ability (n = 417, β = −0.06, SE = 0.05, p = .19); however, an inverse association was identified between the DNAm score and cognitive functioning (N = 7028, β = −0.16, SE = 0.02, p_FDR < 2 × 10⁻¹⁶).

Conclusions

These results suggest methylation-based predictors can be used as proxies for inflammatory markers, potentially allowing for further insight into the relationship between inflammation and pertinent health outcomes.

Functional Capacity and Inflammatory Mediators in Elderly Residents of Counties with Different Human Development Index

A number of studies have indicated that certain factors, including socioeconomic status and education, are associated with the functional health status of the elderly. Another relevant factor in aging is chronic subliminal inflammation, with increased levels of circulating inflammatory cytokines such as interleukin-6 (IL-6), tumor necrosis factor α (TNF-α), and soluble tumor necrosis factor receptor 1 (sTNFR-1), commonly seen in the elderly. High levels of these inflammatory mediators could impair the functional capacity. In this respect, the aim of this cross-sectional study was to compare plasma levels of inflammatory mediators and functional capacity of older women living in three Brazilian counties with different Human Development Index. We evaluated 154 women aged ≥65 years, regardless of race and/or social status. IL-6 and sTNFR-1 plasma levels were measured by ELISA and the functional capacity by the Short Physical Performance Battery (SPPB) test. Comparison among groups was performed using one-way ANOVA with Bonferroni post hoc correction, Kruskal–Wallis, and Mann–Whitney U tests. Women that lived in one of the counties with high HDI had lower functional capacity (p < 0.001). The population from the county with the highest HDI had lower plasma levels of sTNFR-1 (p < 0.05). There was no significant difference in plasma levels of IL-6 (p > 0.05). Besides this, women from the counties with lower HDI had a higher number of self-reported diseases and higher income (p < 0.05). Women that lived in the county with the highest HDI had a higher average education level (p < 0.05). The results showed differences in functional capacity and plasma levels of sTNFR-1 between the counties. In addition, the level of education, family income, and number of self-reported diseases show regional diversities in the aging process, suggesting these factors having an influence on inflammatory mediators and functional capacity.

Influence of the number and severity of comorbidities in the course of acute non-specific low back pain in older adults: longitudinal results from the Back Complaints in the Elders (BACE-Brazil)

BACKGROUND

The presence of comorbidities is quite common in older adults. However, the effects of comorbidities on the course of acute low back pain (LBP) are not fully understood.

OBJECTIVE

To investigate the effects of the number and severity of comorbidities on the severity of pain and disability 3 months from baseline in people with an acute episode of non-specific LBP.

METHODS

Data from the Back Complaints in the Elders study, a cohort that enrolled 602 community-dwelling older adults with acute LBP at baseline, were used in these analyses. Comorbidities, pain intensity and disability were assessed using the Self-Administered Comorbidities Questionnaire (SCQ), the Numeric Rating Scale (NRS) and the Roland-Morris Disability Questionnaire (RMDQ), respectively. Age, sex, marital status, education, income and body mass index were covariates.

RESULTS

The mean age of participants was 67.6 ± 7.0 years. Both pain and disability scores decreased from 7.2 (95% confidence interval [95% CI] 7.0-7.4) to 5.8 (95% CI 5.5-6.1) in NRS and from 13.5 (95% CI 13.0-14.1) to 12.0 (95% CI 11.4-12.7) in RMDQ 3 months from baseline. The linear regression analysis showed a significant association between SCQ scores at baseline and pain (coefficient = 0.16, 95% CI 0.08-0.24; P < 0.001) or disability (coefficient = 0.29, 95% CI 0.16-0.41; P < 0.001) scores at the 3-month follow-up, after adjusting for confounders. Participants with highest SCQ scores were less likely to report improvement of at least 30% in pain (OR: 0.41, 95% CI 0.22-0.79; P = 0.008) and disability (OR: 0.42, 95% CI 0.28-0.85; P = 0.015).

CONCLUSION

The presence and severity of comorbidities were independently associated with the prognosis of acute non-specific LBP in older adults.

Perceived discrimination is associated with the inflammatory response to acute laboratory stress in women at risk for cardiovascular disease

Cardiovascular disease (CVD) is the leading cause of death in the United States and exacts a disproportionate toll on minorities. Growing evidence demonstrates that perceived discrimination is a significant contributing factor to psychological distress, chronic low-grade inflammation, and cardiovascular health. However, little is known regarding the extent to which perceived discrimination contributes to the inflammatory response to acute stress. Therefore, the purpose of this study was to examine the influence of perceived discrimination on the inflammatory response to a laboratory acute stress paradigm in women at risk for CVD. A cross-sectional sample of 99 postmenopausal women (50 African American and 49 non-Hispanic White) (mean age 60.2 years) with at least two risk factors for CVD underwent the Trier Social Stress Test (TSST). Subjects completed the Detroit Area Study Discrimination Scale (DAS-DS) Everyday Discrimination subscale and provided blood and saliva samples prior to the TSST and every 15 min up to 90 min post-TSST to measure a pro-inflammatory cytokine, interleukin-6 (IL-6). Perceived discrimination was significantly associated with the salivary IL-6 response to the TSST (b = 0.49, SE = 0.13, p = <0.001) controlling for age, race, marital status, household income, BMI, statin use, childhood maltreatment, depressive symptoms, and subjective social status. Women who reported higher levels of perceived discrimination had higher levels of salivary IL-6 at baseline and following the TSST as compared to women who reported lower levels of perceived discrimination. Results suggest that higher levels of perceived discrimination, regardless of race and socioeconomic status, may heighten levels of inflammation, prior to and following an acute stress exposure. The circulating Il-6 response was associated with BMI only and did not correlate with salivary IL-6. These data suggest that perceived discrimination may contribute to the salivary-IL-6 acute stress response. However, more research is needed to help clarify the complex relationships among stress and salivary proinflammatory cytokines.

Effects of Horticultural Therapy on Asian Older Adults: A Randomized Controlled Trial

The effect of horticultural therapy (HT) on immune and endocrine biomarkers remains largely unknown. We designed a waitlist-control randomized controlled trial to investigate the effectiveness of HT in improving mental well-being and modulating biomarker levels. A total of 59 older adults was recruited, with 29 randomly assigned to the HT intervention and 30 to the waitlist control group. The participants attended weekly intervention sessions for the first 3 months and monthly sessions for the subsequent 3 months. Biological and psychosocial data were collected. Biomarkers included IL-1β, IL-6, sgp-130, CXCL12/SDF-1α, CCL-5/RANTES, BDNF (brain-derived neurotrophic factor), hs-CRP, cortisol and DHEA (dehydroepiandrosterone). Psychosocial measures examined cognitive functions, depression, anxiety, psychological well-being, social connectedness and satisfaction with life. A significant reduction in plasma IL-6 level (p = 0.02) was observed in the HT intervention group. For the waitlist control group, significant reductions in plasma CXCL12 (SDF-1α) (p = 0.003), CXCL5 (RANTES) (p = 0.05) and BDNF (p = 0.003) were observed. A significant improvement in social connectedness was also observed in the HT group (p = 0.01). Conclusion: HT, in reducing plasma IL-6, may prevent inflammatory disorders and through maintaining plasma CXCL12 (SDF-1α), may maintain hematopoietic support to the brain. HT may be applied in communal gardening to enhance the well-being of older adults.

Handgrip strength, functionality and plasma levels of IL-6 in elderly women

AbstractIntroduction Aging is associated with a chronic low-grade inflammatory process characterized by an increased production of inflammatory mediators. These elevated levels are predictors for muscle function (sarcopenia) and deterioration of physical performance in the elderly.Objective To investigate the correlation between sarcopenia, functional capacity, and interleukin-6 levels.Materials and methods This cross-sectional study assessed a convenience sample of elderly individuals (n = 130) using a handgrip dynamometer (JAMAR™), and the functional capacity test was performed by sitting and standing. Interleukin-6 levels were determined using high sensitivity ELISA kits. Spearman correlation coefficient was used to assess the correlation between these variables, at a significance level (α) of 0.05.Results There was significant inverse correlation between strength and function (rS = -0.273, p = 0.002) such that elderly individuals with lower peak force took longer to perform the sit-to-stand test, in contrast with the relationship between plasma interleukin-6 levels and strength (rS = -0.043, p = 0.624) or functionality (rS = -0.060, p = 0.501).Conclusion The outcome measures analyzed could predict the decline in muscle strength and functional capacity, and may be indicative of sarcopenia in elderly individuals. There was no correlation between the interleukin-6 levels and the grip strength and functional capacity of the sample investigated.