ABSTRACT
Studies on sirtuins (SIRT), a family of proteins with deacetylase activity, have provided convergent evidence of the key role of these enzymes in aging-linked physiological functions. The link between SIRT1 and longevity has emerged in model organism but few data are available in humans, in particular relying on longitudinal studies. Here, we assessed whether a genetic variant within SIRT1 gene promoter (rs12778366) was associated to human longevity. We analyzed 586 genomic DNA (gDNA) collected in the study "Treviso Longeva" (TRELONG), including elderly over 70 years of age from the municipality of Treviso, a town in the Northeast of Italy, with a 11-year follow-up. We genotyped SIRT1 rs12778366 by real-time polymerase chain reaction (RT-PCR) allelic discrimination assay. A cross-sectional analysis performed by comparing people over and under 85 years of age did not evidence association between rs12778366 and longevity. When we performed a longitudinal analysis considering mortality as dependent variable, we did not observe an association of rs12778366 with longevity in the whole population (corrected P-value = 0.33). However, when we stratified the TRELONG subjects according to circulating level of interleukin-6 (IL-6), a predictor of disability and mortality, we found that rs12778366 (TC+CC) carriers were at increased risk of mortality in comparison to the TT reference group (corrected P-value = 0.03, HR 1.47). Our data do not support a major role of rs12778366 in human longevity, but the stratified analysis on IL-6 suggests that this variant may be involved in the detrimental effect of high circulating IL-6 in the elderly.
ABSTRACT
INTRODUCTION: It has been reported that elderly subjects have a compromised ability to produce melatonin nightly, and that reduced melatonin levels may be a risk factor for cancer. The purpose of this study was to evaluate the relationship between melatonin levels and chronic diseases in a cohort of elderly subjects using the Charlson comorbidity index (CCI). DESIGN: We performed a secondary data analysis of a longitudinal study of a representative, age-stratified, sample population. SETTING: The Treviso Longeva (Trelong) study, in Treviso, Italy. PARTICIPANTS: A total of 114 men and 146 women, aged 77 years and older, still alive after 7 years of follow-up. MEASUREMENTS: As an estimation of serum melatonin secretion levels, urinary 6-sulfatoxymelatonin (aMT6s) was assayed in the urine of 260 elderly subjects using an enzyme-linked immunosorbent assay (ELISA) kit (product 01-EK-M6S, ALPCO Immunoassays, Windham, NH). All aMT6s levels were creatinine standardized ([aMT6s]/[creatinine]), and the CCI was calculated. RESULTS: The melatonin levels decreased with aging despite not reaching statistical significance, and the decrease was more evident in males than in females (40.5 ng vs 47.0 ng aMT6s/mg creatinine, ns). Melatonin levels were significantly lower in patients reporting insomnia (p=0.05). The CCI score was inversely correlated with the levels of melatonin (p=0.03). Melatonin levels of subjects affected by CCI pathologies were significantly lower than those of healthy subjects (p=0.03) and of subjects suffering from diseases not included in the CCI and, therefore, less severe (p=0.03). CONCLUSION: Melatonin appears to be a marker of disease state and severity, as well as of sleep disorders, in the elderly. These early findings would confirm the protective role of melatonin against several chronic diseases. The benefits of this agent as a possible medication should be more thoroughly clinically tested.
Subject(s)
Aging/blood , Melatonin/blood , Age Factors , Aged , Aged, 80 and over , Aging/urine , Cardiovascular Diseases/blood , Cardiovascular Diseases/urine , Cohort Studies , Comorbidity , Enzyme-Linked Immunosorbent Assay , Female , Humans , Longitudinal Studies , Male , Melatonin/analogs & derivatives , Melatonin/biosynthesis , Melatonin/urine , Neoplasms/blood , Neoplasms/urine , Renal Insufficiency, Chronic/blood , Renal Insufficiency, Chronic/urine , Risk Factors , Sex Factors , Sleep Initiation and Maintenance Disorders/blood , Sleep Initiation and Maintenance Disorders/drug therapyABSTRACT
Human sirtuins are seven proteins with deacetylase activity that are emerging as key modulators of basic physiological functions. Some evidence links SIRT3 to longevity in mammals. This study aimed to investigate whether variants within SIRT3 gene were associated to human longevity. We analyzed 549 genomic DNA collected during the prospective study "Treviso Longeva," including elderly over 70 years of age from the municipality of Treviso, a small city in the northeast of Italy. We genotyped SIRT3 rs3825075, rs4980329, and rs11555236 single nucleotide polymorphisms (SNPs) by real-time polymerase chain reaction allelic discrimination assay. A cross-sectional analysis performed by comparing people over and under 85 years of age did not evidence association among the SIRT3 SNPs and longevity. However, when we performed a longitudinal analysis considering mortality as a dependent variable, we observed an association of SIRT3 rs11555236 and rs4980329 with longevity in the whole population (p values corrected for potential confounders = 0.04 and 0.03, respectively). After stratification according to gender, the same SNPs were associated to female longevity only (p values corrected for potential confounders = 0.03 and 0.02, respectively). Finally, as rs11555236 was reported to be in linkage disequilibrium with a putative functional enhancer within the SIRT3 gene, we assessed whether rs11555236 genotypes correlated with a different level of SIRT3 protein in peripheral blood mononuclear cells. We found an increased level of SIRT3 in subjects homozygous for the (T) allele. We suggest that SIRT3 genetic variability might be relevant for the modulation of human longevity in the Italian population.
Subject(s)
Longevity/genetics , Polymorphism, Single Nucleotide , Sirtuin 3/genetics , Aged , Aged, 80 and over , Alleles , Blotting, Western , Cross-Sectional Studies , Female , Genotype , Humans , Italy , Linkage Disequilibrium , Longitudinal Studies , Male , Prospective Studies , Real-Time Polymerase Chain ReactionABSTRACT
OBJECTIVES: The concurrent contributions of dynamic, interrelated late-life parameters, such as body mass index (BMI), cognition, and physical functioning on mortality in the elderly are unclear, as is the influence of APOE genotype. We explored these measures in relation to 7-year mortality in long-lived Italian elderly. DESIGN: A representative, age-stratified, population sample. SETTING: The Treviso Longeva (TRELONG) Study, in Treviso, Italy. PARTICIPANTS: Three hundred eleven men and 357 women, aged 70 years and older (mean age 84 ± 8 years). MEASUREMENTS: Seven-year mortality, BMI, Mini-Mental State Examination (MMSE) score, Activities of Daily Living (ADL), APOE genotype, and a variety of clinical and survey data. RESULTS: In separate age- and sex-adjusted analyses, BMI <18.5 kg/m(2), MMSE ≤24, and ADL <6, were associated with greater 7-year mortality among adults aged 70 years and older. In a multivariate model including all factors, MMSE ≤24, and ADL <6 were associated with greater mortality; BMI ≥30 kg/m(2) was protective. There were no interactions between BMI, MMSE, or ADL. When excluding those dying within 3 years of baseline, only an MMSE ≤24 was related to mortality. APOEε4 was not related to mortality. CONCLUSION: Higher MMSE score, higher ADL score, and higher BMI, independent of age, sex, and other factors, are markers for longer life among northern Italian adults aged 70 years or older. Global cognition, BMI, and physical functioning, assessed by short, simple tests are profound indicators of death within less than a decade.
Subject(s)
Activities of Daily Living/psychology , Aging/genetics , Aging/psychology , Apolipoproteins E/genetics , Body Mass Index , Cognition/physiology , Mortality , Aged , Aged, 80 and over , Disability Evaluation , Female , Genotype , Humans , Male , Neuropsychological Tests/statistics & numerical dataABSTRACT
Insulin-like growth factor 1 (IGF-1) signaling modulation has been associated with increased lifespan in model organisms, while high levels of circulating interleukin-6 (IL-6) are a marker of disability and mortality. In the prospective, population-based "Treviso Longeva"--TRELONG Study from Italy (n = 668, age range 70-105.5 years at baseline, followed for seven years) we investigated the effects of survival on the IGF-1 receptor (IGF-1R) gene polymorphism rs2229765, the IL-6 gene promoter polymorphism rs1800795, and plasma concentrations of IGF-1 and IL-6, alone or in combination. We found a sex-dependent effect for the IGF-1R rs2229765 polymorphism, as male carriers of the homozygous A/A genotype survived longer, while the IL-6 rs1800795 genotype did not influence overall or sex-specific longevity. Higher IL-6 levels were more detrimental for survival among males than females, while IGF-1 had no dose-response effect. These findings sustain the hypothesis that sex-specific longevity relies on detectable differences in genetic and biochemical parameters between males and females.