Seropositivity for CMV and IL-6 levels are associated with grip strength and muscle size in the elderly

Abstract

BackgroundSarcopenia is an important cause of morbidity and mortality in older adults, with immunosenescence and inflammation being possible underlying mechanisms. We investigated the relationship between latent cytomegalovirus (CMV) infection, Interleukin 6 (IL-6) levels, muscle size and strength in a group of healthy older community-dwelling people.MethodsParticipants were healthy volunteers from the Lothian Birth Cohort 1936 study. Participants had IL-6 level and CMV antibody titre measured at age 70 years and grip strength and a volumetric T1-weighted MRI brain scan (allowing measurement of neck muscle cross-sectional area (CSA)) at age 73. Markers of childhood deprivation were adjusted for in the analysis due to correlations between childhood deprivation and latent CMV infection.Results866 participants were studied; 448 men (mean age 72.48 years, sd 0.70) and 418 women (mean age 72.51 years, sd 0.72). In men, CMV seropositivity was associated with smaller neck muscle CSA (p = 0.03, partial eta squared = 0.01), even after adjustment for IL-6 levels. Neck muscle CSA was not associated with CMV seropositivity in women, or CMV antibody titre or IL-6 level in either sex. Grip strength associated negatively with IL-6 level (right grip strength p<0.00001, partial eta squared 0.032 and left grip strength p<0.00001, partial eta squared 0.027) with or without adjustment for CMV serostatus or antibody titre. CMV status and antibody titre were not significantly associated with grip strength in either hand.ConclusionThese findings support the hypothesis that there is a relationship between markers of immunosenescence (i.e. CMV serostatus and IL6 level) and low muscle mass and strength and longitudinal studies in older cohorts are now required to investigate these relationships further.

Cytomegalovirus infection does not impact on survival or time to first treatment in patients with chronic lymphocytic leukemia

“…Despite this, no published epidemiological data exists investigating the relationship between CMV and B‐CLL prognosis. This work, reports the prevalence of HCMV within the two cohorts was approximately 60%–70%, which is comparable with studies of viral seroprevalence in healthy people at a similar median age of 64 years 23. As such we find no evidence that CMV infection is associated with the development of B‐CLL.…”

“…This may be due partly to the younger age of the patients with B‐CLL compared with studies of healthy elderly people, which have focused predominantly on those between 70 and 100 years of age 11, 28, 29. In addition, the detrimental impact of chronic HCMV on the health of older people has been linked with elevated levels of inflammatory markers, including IL‐6 23, 30, 31, which are often already increased in patients with B‐CLL and may therefore confound any impact of HCMV on further health outcomes 32, 33. It may also suggest that any negative effect of HCMV infection in the elderly is outweighed by a diagnosis of B‐CLL.…”

“…HCMV seropositivity and HCMV IgG titer were determined using the previously described CMV enzyme‐linked immunosorbent assay (ELISA) 23. Briefly, mock and viral‐infected lysate was coated onto ELISA plates and incubated overnight.…”

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

“…Study where CMV serostatus was not associated with frailty (Collerton et al 2012). Another recent study by Kilgour et al found a significant impact of CMV serostatus on HGS in women, but not men (both 72 years old), a significant negative correlation of CMV antibody titers with HGS (right hand in women and left hand in men) and a negative correlation of IL-6 titers with HGS in men, but not women (Kilgour et al 2013). In the BASE-II cohort no correlations of HGS with IL-6 levels were observed, but again elderly men seemed to be differently affected, as IL-6 concentrations were significantly higher compared to women.…”

“…Potential clinical relevance of such results is illustrated for example in reports of associations of IL-6 levels with survival of the very elderly (Wikby et al 2006). IL-6 levels correlated in another study negatively with HGS, wherein CMV serostatus and antibody titers did not correlate with IL-6 levels (Kilgour et al 2013). In addition, inflammation in the elderly-determined by IL-1RA, IL-6, CRP and TNF levels-was demonstrated to be associated with adiposity and lower survival (Lisko et al 2012).…”