Giulia Ogliari

Role of epigenetics in human aging and longevity: genome-wide DNA methylation profile in centenarians and centenarians' offspring.

The role of epigenetics in the modulation of longevity has not been studied in humans. To this aim, (1) we evaluated the DNA methylation from peripheral leukocytes of 21 female centenarians, their 21 female offspring, 21 offspring of both non-long-lived parents, and 21 young women through ELISA assay, pyrosequencing analysis of Alu sequences, and quantification of methylation in CpG repeats outside CpG islands; (2) we compared the DNA methylation profiles of these populations through Infinium array for genome-wide CpG methylation analysis. We observed an age-related decrease in global DNA methylation and a delay of this process in centenarians’ offspring. Interestingly, literature data suggest a link between the loss of DNA methylation observed during aging and the development of age-associated diseases. Genome-wide methylation analysis evidenced DNA methylation profiles specific for aging and longevity: (1) aging-associated DNA hypermethylation occurs predominantly in genes involved in the development of anatomical structures, organs, and multicellular organisms and in the regulation of transcription; (2) genes involved in nucleotide biosynthesis, metabolism, and control of signal transmission are differently methylated between centenarians’ offspring and offspring of both non-long-lived parents, hypothesizing a role for these genes in human longevity. Our results suggest that a better preservation of DNA methylation status, a slower cell growing/metabolism, and a better control in signal transmission through epigenetic mechanisms may be involved in the process of human longevity. These data fit well with the observations related to the beneficial effects of mild hypothyroidism and insulin-like growth factor I system impairment on the modulation of human lifespan.

Remodelling of biological parameters during human ageing: evidence for complex regulation in longevity and in type 2 diabetes.

Factor structure analyses have revealed the presence of specific biological system markers in healthy humans and diseases. However, this type of approach in very old persons and in type 2 diabetes (T2DM) is lacking. A total sample of 2,137 Italians consisted of two groups: 1,604 healthy and 533 with T2DM. Age (years) was categorized as adults (≤65), old (66–85), oldest old (>85–98) and centenarians (≥99). Specific biomarkers of routine haematological and biochemical testing were tested across each age group. Exploratory factorial analysis (EFA) by principal component method with Varimax rotation was used to identify factors including related variables. Structural equation modelling (SEM) was applied to confirm factor solutions for each age group. EFA and SEM identified specific factor structures according to age in both groups. An age-associated reduction of factor structure was observed from adults to oldest old in the healthy group (explained variance 60.4% vs 50.3%) and from adults to old in the T2DM group (explained variance 57.4% vs 44.2%). Centenarians showed three-factor structure similar to those of adults (explained variance 58.4%). The inflammatory component became the major factor in old group and was the first one in T2DM. SEM analysis in healthy subjects suggested that the glucose levels had an important role in the oldest old. Factorial structure change during healthy ageing was associated with a decrease in complexity but showed an increase in variability and inflammation. Structural relationship changes observed in healthy subjects appeared earlier in diabetic patients and later in centenarians.

Blood pressure and 10-year mortality risk in the Milan Geriatrics 75+ Cohort Study: role of functional and cognitive status

BACKGROUND Optimal blood pressure targets in older adults are controversial. OBJECTIVE to investigate whether the relation of blood pressure with mortality in older adults varies by age, functional and cognitive status. DESIGN longitudinal geriatric outpatient cohort. SETTING Milan Geriatrics 75+ Cohort Study. SUBJECTS One thousand five hundred and eighty-seven outpatients aged 75 years and over. METHODS The relations of systolic (SBP) and diastolic blood pressure (DBP) with mortality risk were analysed using Cox proportional hazards models. Blood pressure, Mini-Mental State Examination (MMSE) and Basic Activities of Daily Living (ADL) were assessed at baseline. All analyses were adjusted for socio-demographic factors, co-morbidities and medications. RESULTS One thousand and forty-six patients died during 10-year follow-up. The relationships of SBP and DBP with mortality risk were U-shaped; SBP of 165 mmHg and DBP of 85 mmHg were associated with the lowest mortality. Patients with SBP < 120 mmHg and patients with SBP 120-139 mmHg had 1.64-fold (95% confidence intervals, CI 1.21-2.23) and 1.32-fold (95% CI 1.10-1.60) higher mortality risk than patients with SBP 160-179 mmHg (P values 0.001 and 0.004, respectively). In patients with SBP below 180 mmHg, higher SBP was associated with lower mortality in patients with impaired ADL and MMSE but not in those with preserved ADL and/or MMSE (P for interaction 0.033). Age did not modify the correlation of SBP with mortality. CONCLUSIONS The correlations of SBP and DBP with mortality were U-shaped. Higher SBP is related to lower mortality in subjects with impaired ADL and MMSE. ADL and MMSE may identify older subjects who benefit from higher blood pressure.

Variations of the angiotensin II type 1 receptor gene are associated with extreme human longevity

Longevity phenotype in humans results from the influence of environmental and genetic factors. Few gene polymorphisms have been identified so far with a modest effect on lifespan leaving room for the search of other players in the longevity game. It has been recently demonstrated that targeted disruption of the mouse homolog of the human angiotensin II type 1 receptor (AT1R) gene (AGTR1) translates into marked prolongation of animal lifespan (Benigni et al., J Clin Invest 119(3):524–530, 2009). Based on the above study in mice, here we sought to search for AGTR1 variations associated to reduced AT1 receptor protein levels and to prolonged lifespan in humans. AGTR1 was sequenced in 173 Italian centenarians and 376 younger controls. A novel non-synonymous mutation was detected in a centenarian. Two polymorphisms in AGTR1 promoter, rs422858 and rs275653, in complete linkage disequilibrium, were significantly associated with the ability to attain extreme old age. We then replicated the study of rs275653 in a large independent cohort of Japanese origin (598 centenarians and semi-supercentenarians, 422 younger controls) and indeed confirmed its association with exceptional old age. In combined analyses, rs275653 was associated to extreme longevity either at recessive model (P = 0.007, odds ratio (OR) 3.57) or at genotype level (P = 0.015). Significance was maintained after correcting for confounding factors. Fluorescence activated cell sorting analysis revealed that subjects homozygous for the minor allele of rs275653 had less AT1R-positive peripheral blood polymorphonuclear cells. Moreover, rs275653 was associated to lower blood pressure in centenarians. These findings highlight the role of AGTR1 as a possible candidate among longevity-enabling genes.

Immune parameters identify Italian centenarians with a longer five-year survival independent of their health and functional status

Centenarians are rare and exceptional individuals characterized by a peculiar phenotype. They are the best example of healthy aging in humans as most of them have escaped or substantially delayed the onset of major age-related diseases. Within this scenario, the purpose of the present work was to understand if immune status is associated with survival and health status in centenarians. To this aim, 116 centenarians were concomitantly characterized for their immunological, health and functional status, and followed-up for five-year survival. On the basis of previous knowledge we focused on a core of fundamental and basic immune parameters (number of leukocytes, monocytes, total lymphocytes, CD3(+) T lymphocytes, CD4(+) helper T lymphocytes, CD8(+) cytotoxic T lymphocytes, CD19(+) B lymphocytes and plasma levels of IgM), and the most important findings can be summarized as follows: i. a hierarchical cluster analysis was able to define Cluster1 (88 centenarians) and Cluster2 (28 centenarians) characterized by low and high values of all these immune parameters, respectively; ii. centenarians of Cluster2 showed a statistically longer five-year survival and more favorable values of other important immune (naïve, activated/memory and effector/memory T cells) and metabolic (glycemia, insulin and HOMA-IR) parameters, in accord with previous observations that centenarians have a peculiar immune profile, a preserved insulin pathway and a lower incidence of type 2 diabetes; and iii. unexpectedly, parameters related to frailty, as well as functional and cognitive status, did not show any significant correlation with the immune clustering, despite being capable per se of predicting survival. In conclusion, high values of basic immunological parameters and important T cell subsets correlate with five-year survival in centenarians, independent of other phenotypic characteristics. This unexpected biological scenario is compatible with the general hypothesis that in centenarians a progressive disconnection and loss of biological coherence among the different functions of the body occur, where survival/mortality result from the failure of any of these domains which apparently follow an independent age-related trajectory.

Hemostasis and ageing

On March 19, 2008 a Symposium on Pathophysiology of Ageing and Age-Related Diseases was held in Palermo, Italy. The lecture of D. Mari on Hemostasis and ageing is summarized herein. Physiological ageing is associated with increased plasma levels of many proteins of blood coagulation together with fibrinolysis impairment. This may be of great concern in view of the known association between vascular and thromboembolic diseases and ageing. On the other hand, centenarians are characterized by a state of hypercoagulability and possession of several high-risk alleles and well-known atherothrombotic risk markers but this appears to be compatible with longevity and/or health. Parameters considered risk factors for atherosclerotic vascular diseases in young people may lose their biological significance in advanced age and assume a different role.

Age- and Functional Status–Dependent Association Between Blood Pressure and Cognition: The Milan Geriatrics 75+ Cohort Study

To evaluate whether the relationship between blood pressure (BP) measures and cognitive function is different according to age and functional status in older outpatients.

Common adipokine features of neonates and centenarians

Abstract Adipose tissue seems to be a pivotal organ in the aging process. We investigated whether healthy aging could have its roots in a sound metabolic condition from the first year of life by evaluating leptin and adiponectin levels in neonates [33 adequate for gestational age (AGA) and 29 small for gestational age (SGA)], 48 centenarians, and 50 healthy elderly subjects. At birth, SGA neonates showed lower leptin levels (SGA 0.88±0.28; AGA 2.22±0.91 ng/mL; p<0.05) and comparable adiponectin levels with respect to AGA. At 1 year, SGA showed increased leptin (SGA 1.74±0.28; AGA 1.31±0.19 ng/mL) and slightly reduced adiponectin concentrations (SGA 35.51±2.53; AGA 38.56±3.18 μg/mL) than AGA. Centenarians showed lower leptin (centenarians 18.71±3.78; elderly 34.81±7.27 ng/mL; p<0.05) and higher adiponectin levels (centenarians 55.63±7.7; elderly 33.51±4.1 μg/mL; p<0.05) than elderly subjects. Centenarians, like AGA infants during the first year of life, show a favorable adipokine profile, suggesting that the metabolic condition at early age could affect the longevity of an individual.

Resting heart rate, heart rate variability and functional decline in old age

Background: Heart rate and heart rate variability, markers of cardiac autonomic function, have been linked with cardiovascular disease. We investigated whether heart rate and heart rate variability are associated with functional status in older adults, independent of cardiovascular disease. Methods: We obtained data from the Prospective Study of Pravastatin in the Elderly at Risk (PROSPER). A total of 5042 participants were included in the present study, and mean follow-up was 3.2 years. Heart rate and heart rate variability were derived from baseline 10-second electrocardiograms. Heart rate variability was defined as the standard deviation of normal-to-normal RR intervals (SDNN). Functional status in basic (ADL) and instrumental (IADL) activities of daily living was measured using Barthel and Lawton scales, at baseline and during follow-up. Results: The mean age of the study population was 75.3 years. At baseline, higher heart rate was associated with worse ADL and IADL, and lower SDNN was related to worse IADL (all p values < 0.05). Participants in the highest tertile of heart rate (range 71–117 beats/min) had a 1.79-fold (95% confidence interval [CI] 1.45–2.22) and 1.35-fold (95% CI 1.12–1.63) higher risk of decline in ADL and IADL, respectively (p for trend < 0.001 and 0.001, respectively). Participants in the lowest tertile of SDNN (range 1.70–13.30 ms) had 1.21-fold (95% CI 1.00–1.46) and 1.25-fold (95% CI 1.05–1.48) higher risk of decline in ADL and IADL, respectively (both p for trends < 0.05). All associations were independent of sex, medications, cardiovascular risk factors and comorbidities. Interpretation: Higher resting heart rate and lower heart rate variability were associated with worse functional status and with higher risk of future functional decline in older adults, independent of cardiovascular disease. This study provides insight into the role of cardiac autonomic function in the development of functional decline.

Visit-to-visit blood pressure variability and future functional decline in old age.

Objective: Higher blood pressure variability (BPV), independent of mean blood pressure (BP), has been associated with adverse health outcomes. We investigated the association between visit-to-visit BPV and functional decline in older adults at high cardiovascular risk. Methods: In PROspective Study of Pravastatin in the Elderly at Risk, 4745 participants with mean age of 75.2 years and high cardiovascular risk were followed for a mean of 3.2 years. BP was measured in every 3 months during the first 18 months. BPV was defined as the intraindividual SD of measurements across these visits. Functional status in basic and instrumental activities of daily living was measured using the Barthel (ADL) and Lawton (IADL) scales, first at 18 months and then during follow-up until 48 months. Functional decline was calculated over this period. Results: BPV was not cross-sectionally associated with functional status at 18 months. Higher SBPV was associated with steeper functional decline, whereas DBPV was not. Each 10 mmHg higher SBPV was associated with a 0.064 (95% confidence interval 0.016–0.112, P = 0.009) annual decline in ADL score and with a 0.078 decline (95% confidence interval 0.020–0.136, P = 0.008) in IADL score. These associations were not modified by sex, hypertension or antihypertensives. These findings were independent of mean BP, cardiovascular risk factors and morbidities and cognition. Conclusion: Higher visit-to-visit SBPV but not DBPV was associated with steeper functional decline in older adults at high cardiovascular risk. Higher SBPV is a novel risk factor for functional decline.