[Immunological markers of ageing]

[Lipid peroxidation in the lymphocyte membrane and protein oxidation in the serum of elderly people. Are they potential markers of frailty and dependence? Preliminary results]

OBJECTIVE

To study the relationships between lipid peroxidation of the lymphocyte membrane, protein oxidation and different markers of frailty and dependence.

METHODS

The sample consisted of 15 elderly patients in an intermediate and long-term care center, who had not suffered any acute process recently. The geriatric assessment included, functional capacity (Barthel and Lawton indexes), comorbidity (Charlson index), and cognitive function (Mini Mental State Examination of Folstein). The frailty was estimated by the Hospital Admission Risk Profile (high risk of frailty 4-5 points, intermediate/low 0-3 points) and Frailty Scale of Rockwood (mild frailty<6, intermediate frailty/severe≥6). Lipid peroxidation was studied by determination of conjugated dienes and trienes. Analysis of protein oxidation was performed by determining malondialdehyde bound to plasma proteins, corrected by total protein quantification.

RESULTS

Elderly patients at high risk of frailty according to Hospital Admission Risk Profile presented mean values of conjugated dienes of 7.94±1.32%, trienes of 1.75±0.51%, and malondialdehyde bound to plasma proteins of 141.9±27.3nmol/g. In the group of intermediate/low risk, these values were 4.96±2.77% (P=.035), 1.37±0.78% (P=.337) and 96.4±31.5nmol/g (P=.022), respectively. In those with intermediate/severe frailty according to the Frailty Scale of Rockwood, these values were 7.06±2.18%; 1.73±0.50% and 119.6±37.9nmol/g, respectively, and in those with mild frailty 2.56±1.48% (P=014); 0.61±0.58% (P=020) and 173.2±51.9nmol/g (P=.144), respectively. There was good correlation between the Hospital Admission Risk Profile score and malondialdehyde bound to plasma proteins (r=0.70; P=01) and between the Frailty Scale of Rockwood score and conjugated dienes (r=0.65; P=01).

CONCLUSIONS

Elderly patients with a higher degree of frailty appear to have greater levels of lipid peroxidation, which could be considered a marker of frailty.

[Oxidative stress and longevity; a case-control study]

INTRODUCTION

Human longevity is a complex issue influenced by genetic and environmental factors. Oxidative stress (OE) could play an important role in this process. Succesful aging could be related with the organism ability facing OE. In the present study we compared malondialdehyde (MDA) and oxidized proteins (OP) plasma levels, in elderly people older than 97 years and 70-80 years old, to better understand the effects of OE on human longevity.

MATERIAL AND METHODS

Population-based case control study. We considered as cases patients who were born and live on la Ribera county in Valencia (Spain) older than 97 years old and who accepted to participate in the study. Controls were from the same poblational base, chosen randomly, and 70-80 years old. We made a descriptive analysis of sociodemographic, clinic and functional variables; an odds ratio (OR) estimation of being centenarian by OP and MDA quartiles; and a tendency analysis by Mantel-Haenszel test.

RESULTS

Twenty eight cases and 31 controls were included. Functional state and robust percentage were worse in cases. MDA (1,44±0,45 vs 1,84±0,59, p=0,005), and OP (64,29±15,73 vs. 76,52±13,44, p=0,002) levels, were significantly lower in cases. The OR of being centenarian in lower/higher quartile were 3,8 for MDA and 5,7 for OP, with a Mantel-Haenszel signification of 0,029 and 0,044 respectively.

CONCLUSIONS

In our study OE level were lower in centenarians than in younger elderly, and the lower the OE grade, the higher were the likelihood of being centenarian.

Differences according to gender and health status in CD4:CD8 ratio in a sample of community-dwelling oldest old. The OCTABAIX immune study

BACKGROUND AND AIMS

The presence of an immune-risk phenotype (IRP) has been correlated with survival rates in elderly people. The aim of this study is to characterize the inverted CD4:CD8 ratio as a possible marker of IRP in a sample of oldest old (85 years) by assessing differences in gender and health status.

METHODS

Comorbidity, functional status (Barthel Index), and cognitive status with the Spanish version of the Mini-Mental State Examination were evaluated. Non-disabled subjects were defined as those with better health status, with scores of >90 on the Barthel Index and >23 points on the Spanish version of the Mini-Mental State Examination. CD4:CD8 ratios were recorded, and a ratio of 1.00 or less was used to define IRF.

RESULTS

Three hundred and twelve subjects aged 85 years old were studied, 190 women (60.9%) and 122 men. The CD4:CD8 ratio was 1.00 or less in 47 subjects (15.6%) and higher than 2.2 in 115 (36.8%). There were no differences in CD4:CD8 ratio according to health status. The inverted CD4:CD8 ratio was more frequent in men (55.3%).

CONCLUSION

In this community-dwelling, single year birth cohort study, the subgroup with poor health status did not have a lower CD4:CD8 ratio. The inverted CD4:CD8 ratio was more frequent in men.