@article {1205, title = {Polymorphisms in the mitochondrial DNA control region and frailty in older adults.}, journal = {PLoS One}, volume = {5}, year = {2010}, month = {2010 Jun 10}, pages = {e11069}, abstract = {

BACKGROUND: Mitochondria contribute to the dynamics of cellular metabolism, the production of reactive oxygen species, and apoptotic pathways. Consequently, mitochondrial function has been hypothesized to influence functional decline and vulnerability to disease in later life. Mitochondrial genetic variation may contribute to altered susceptibility to the frailty syndrome in older adults.

METHODOLOGY/PRINCIPAL FINDINGS: To assess potential mitochondrial genetic contributions to the likelihood of frailty, mitochondrial DNA (mtDNA) variation was compared in frail and non-frail older adults. Associations of selected SNPs with a muscle strength phenotype were also explored. Participants were selected from the Cardiovascular Health Study (CHS), a population-based observational study (1989-1990, 1992-1993). At baseline, frailty was identified as the presence of three or more of five indicators (weakness, slowness, shrinking, low physical activity, and exhaustion). mtDNA variation was assessed in a pilot study, including 315 individuals selected as extremes of the frailty phenotype, using an oligonucleotide sequencing microarray based on the Revised Cambridge Reference Sequence. Three mtDNA SNPs were statistically significantly associated with frailty across all pilot participants or in sex-stratified comparisons: mt146, mt204, and mt228. In addition to pilot participants, 4,459 additional men and women with frailty classifications, and an overlapping subset of 4,453 individuals with grip strength measurements, were included in the study population genotyped at mt204 and mt228. In the study population, the mt204 C allele was associated with greater likelihood of frailty (adjusted odds ratio = 2.04, 95\% CI = 1.07-3.60, p = 0.020) and lower grip strength (adjusted coefficient = -2.04, 95\% CI = -3.33- -0.74, p = 0.002).

CONCLUSIONS: This study supports a role for mitochondrial genetic variation in the frailty syndrome and later life muscle strength, demonstrating the importance of the mitochondrial genome in complex geriatric phenotypes.

}, keywords = {Aged, Aged, 80 and over, DNA, Mitochondrial, Female, Frail Elderly, Genotype, Humans, Male, Polymorphism, Genetic}, issn = {1932-6203}, doi = {10.1371/journal.pone.0011069}, author = {Moore, Ann Z and Biggs, Mary L and Matteini, Amy and O{\textquoteright}Connor, Ashley and McGuire, Sarah and Beamer, Brock A and Fallin, M Danielle and Fried, Linda P and Walston, Jeremy and Chakravarti, Aravinda and Arking, Dan E} } @article {6608, title = {Simple biologically informed inflammatory index of two serum cytokines predicts 10 year all-cause mortality in older adults.}, journal = {J Gerontol A Biol Sci Med Sci}, volume = {69}, year = {2014}, month = {2014 Feb}, pages = {165-73}, abstract = {

BACKGROUND: Individual measurements of inflammation have been utilized to assess adverse outcomes risk in older adults with varying degrees of success. This study was designed to identify biologically informed, aggregate measures of inflammation for optimal risk assessment and to inform further biological study of inflammatory pathways.

METHODS: In total, 15 nuclear factor-kappa B-mediated pathway markers of inflammation were first measured in baseline serum samples of 1,155 older participants in the InCHIANTI population. Of these, C-reactive protein, interleukin-1-receptor antagonist, interleukin-6, interleukin-18, and soluble tumor necrosis factor-α receptor-1 were independent predictors of 5-year mortality. These five inflammatory markers were measured in baseline serum samples of 5,600 Cardiovascular Health Study participants. A weighted summary score, the first principal component summary score, and an inflammation index score were developed from these five log-transformed inflammatory markers, and their prediction of 10-year all-cause mortality was evaluated in Cardiovascular Health Study and then validated in InCHIANTI.

RESULTS: The inflammation index score that included interleukin-6 and soluble tumor necrosis factor-α receptor-1 was the best predictor of 10-year all-cause mortality in Cardiovascular Health Study, after adjusting for age, sex, education, race, smoking, and body mass index (hazards ratio = 1.62; 95\% CI: 1.54, 1.70) compared with all other single and combined measures. The inflammation index score was also the best predictor of mortality in the InCHIANTI validation study (hazards ratio 1.33; 95\% CI: 1.17-1.52). Stratification by sex and CVD status further strengthened the association of inflammation index score with mortality.

CONCLUSION: A simple additive index of serum interleukin-6 and soluble tumor necrosis factor-α receptor-1 best captures the effect of chronic inflammation on mortality in older adults among the 15 biomarkers measured.

}, keywords = {Aged, Aged, 80 and over, Biomarkers, C-Reactive Protein, Cohort Studies, Female, Humans, Inflammation, Interleukin 1 Receptor Antagonist Protein, Interleukin-18, Interleukin-6, Longevity, Male, Receptors, Tumor Necrosis Factor, Type I, Risk Factors}, issn = {1758-535X}, doi = {10.1093/gerona/glt023}, author = {Varadhan, Ravi and Yao, Wenliang and Matteini, Amy and Beamer, Brock A and Xue, Qian-Li and Yang, Huanle and Manwani, Bhavish and Reiner, Alexander and Jenny, Nancy and Parekh, Neel and Fallin, M Daniele and Newman, Anne and Bandeen-Roche, Karen and Tracy, Russell and Ferrucci, Luigi and Walston, Jeremy} }