Summary: Blood samples taken from older adults who experienced social isolation had higher levels of interleukin-6 and C-reactive protein, two biomarkers of inflammation.
Source: Wiley
In a study published in the Journal of the American Geriatrics Society, older US adults who experienced social isolation had higher blood levels of interleukin-6 and C-reactive protein, two markers of inflammation that can have long-term negative consequences for the health of individuals as they age.
The study included a nationally representative sample of 4,648 Medicare beneficiaries aged 65 years and older.
The authors noted that clinical and social interventions that address social isolation among older adults may influence biological processes such as inflammation, as well as their potentially negative effects.

“Our findings demonstrate an important association between social isolation and biological processes. This work is a step in the journey to disentangle the mechanisms by which social isolation leads to higher levels of morbidity and mortality,” said lead author Thomas K.M. Cudjoe, MD, MPH, of Johns Hopkins School of Medicine.
“My hope is that investigators incorporate objective measures of social isolation and biological markers in future longitudinal studies so that we might continue to advance our understanding of these complex biopsychosocial interactions.”
About this aging and inflammation research news
Author: Katherine Falzon
Source: Wiley
Contact: Katherine Falzon – Wiley
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Original Research: Open access.
“Getting under the skin: Social isolation and biological markers in the National Health and Aging Trends Study” by Thomas K.M. Cudjoe et al. Journal of the American Geriatrics Society
Abstract
Getting under the skin: Social isolation and biological markers in the National Health and Aging Trends Study
Background
Social isolation is a risk factor for morbidity and mortality comparable to well-established risk factors including smoking, hypertension, and a sedentary lifestyle. The specific biological mechanisms that connect social isolation to morbidity and mortality remain unclear. Interleukin-6 (IL-6) and C-reactive protein (CRP) are biological markers that are upregulated during inflammation and can have long-term negative consequences for the health of individuals as they age.
Methods
Utilizing Round 7 (2017) data from the National Health and Aging Trends Study (NHATS), we examine the relationship between social isolation and two biological markers: IL-6 and high-sensitivity CRP. This study included a nationally representative sample of 4648 Medicare beneficiaries 65 years and older who provided samples using dried blood spot (DBS) techniques. We defined social isolation utilizing a multi-domained typology that considers living arrangement, core discussion network, religious attendance, and social participation. IL-6 and CRP were obtained via DBS that were collected in Round 7 of the NHATS. We performed linear regression to examine the association between social isolation and biological markers IL-6 and CRP.
Results
After adjusting for age, gender, race/ethnicity, income, tobacco use, body mass index, and chronic conditions, we found that severe social isolation and social isolation were significantly associated with higher levels of IL-6 and CRP values among older adults.
Conclusions
Social isolation is associated with higher levels of biological markers (IL-6 and CRP). Our findings inform the pathway between social isolation and morbidity and mortality among older adults. IL-6 or CRP could be a proximal outcome measures for future clinical and social interventions that seek to alter the trajectory of social isolation and its associated health outcomes.