Nature or nurture; BMI and blood pressure at 90. Findings from the Belfast Elderly Longitudinal Free-living Aging STudy (BELFAST)

Hypertension and its Correlates in the Oldest Old Population Aged 80 Years and Above in Urban South India

BACKGROUND

Hypertension is a major problem among the geriatric population, presenting the risk of multiple associated co-morbidities and organ system damage. Data related to the epidemiology of controlled and uncontrolled hypertension among the oldest old population is sparse, more so from developing countries. The objectives of the present paper were to identify the prevalence and correlates of hypertension according to gender among the urban community-dwelling healthy oldest old population.

METHODS

200 healthy people aged 80 years and above were recruited by random selection from Hyderabad city of South India in 2017. A trained investigator collected data on background history, history of hypertension and other co-morbidities, medications and sleep. Participants were tested for muscle strength, gait speed, and SPPB and cognitive impairment.

RESULTS

The prevalence of hypertension was 83.5%; 81.6% among men and 84.7% among women. 64.5% was self-reported. Hypertension was controlled with treatment among only 46.2%. In 74.6%, it was controlled even without treatment. The independent correlates were BMI per SD increase (OR: 1.92, 95% CI: 1.17-3.16), diabetes (OR: 6.02, 95% CI: 1.24-29.11) and asthma (OR: 3.59, 95% CI: 1.05-12.29). Among men, BMI per SD increase was significantly associated while hemoglobin per SD increase, height per SD decrease, and arthritis were positively associated among women. Increasing heart rate among total subjects (OR: 0.44, 95% CI: 0.27-0.71), and among women (OR: 0.47, 95% CI: 0.24-0.92) showed a negative association.

CONCLUSION

The prevalence of hypertension was high. The correlates were different for men and women. Subjects were unaware of their control status which posed an increased risk for organ damage, and development of co-morbidities. Policies aimed at improving quality of life of the oldest old should place due stress on appropriate hypertension management in developing countries.

Genes and life-style factors in BELFAST nonagenarians: Nature, Nurture and Narrative

Understanding how to 'Age Longer and Age Well' is a priority for people personally, for populations globally and for government policy. Nonagenarians are the oldest members of our societies and survivors of their generation. Approximately 10 % of nonagenarians reach 90 years and beyond in good condition and seem to have a combination of both age-span and health-span. But what are the factors which help people reach their ninetieth birthday and beyond in good condition? Are they genetics, as in 'nature', or do they depend on 'nurture' and are related to environment, or are both factors inextricably intertwined within the concept of behavioural genetics? Nonagenarians have rich life experiences that can teach us much about ageing well; they are reservoirs of genetic, life-style and behavioural information which can help dissect out how to live not only longer but better. Personal family history and narrative are powerful tools that help to determine familial traits, beliefs and social behaviours and when used in parallel with new biotechnology methods inform and elaborate causality. Here we present themes and insights from personal narrative enquiry from nonagenarian participants from the Belfast Elderly Longitudinal Free-living Ageing STudy (BELFAST) about factors they consider important for good quality ageing and relate these insights to the emerging genetics and life-style evidence associated with healthy longevity.

Living long and ageing well: is epigenomics the missing link between nature and nurture?

Human longevity is a complex trait and increasingly we understand that both genes and lifestyle interact in the longevity phenotype. Non-genetic factors, including diet, physical activity, health habits, and psychosocial factors contribute approximately 50% of the variability in human lifespan with another 25% explained by genetic differences. Family clusters of nonagenarian and centenarian siblings, who show both exceptional age-span and health-span, are likely to have inherited facilitatory gene groups, but also have nine decades of life experiences and behaviours which have interacted with their genetic profiles. Identification of their shared genes is just one small step in the link from genes to their physical and psychological profiles. Behavioural genomics is beginning to demonstrate links to biological mechanisms through regulation of gene expression, which directs the proteome and influences the personal phenotype. Epigenetics has been considered the missing link between nature and nurture. Although there is much that remains to be discovered, this article will discuss some of genetic and environmental factors which appear important in good quality longevity and link known epigenetic mechanisms to themes identified by nonagenarians themselves related to their longevity. Here we suggest that exceptional 90-year old siblings have adopted a range of behaviours and life-styles which have contributed to their ageing-well-phenotype and which link with important public health messages.

Killer Immunoglobulin-like Receptors (KIR) haplogroups A and B track with Natural Killer Cells and Cytokine Profile in Aged Subjects: Observations from Octo/Nonagenarians in the Belfast Elderly Longitudinal Free-living Aging STudy (BELFAST)

BACKGROUND

Natural Killer Cells (NK) play an important role in detection and elimination of virus-infected, damaged or cancer cells. NK cell function is guided by expression of Killer Immunoglobulin-like Receptors (KIRs) and contributed to by the cytokine milieu. KIR molecules are grouped on NK cells into stimulatory and inhibitory KIR haplotypes A and B, through which NKs sense and tolerate HLA self-antigens or up-regulate the NK-cytotoxic response to cells with altered HLA self-antigens, damaged by viruses or tumours. We have previously described increased numbers of NK and NK-related subsets in association with sIL-2R cytokine serum levels in BELFAST octo/nonagenarians. We hypothesised that changes in KIR A and B haplotype gene frequencies could explain the increased cytokine profiles and NK compartments previously described in Belfast Elderly Longitudinal Free-living Aging STudy (BELFAST) octo/nonagenarians, who show evidence of ageing well.

RESULTS

In the BELFAST study, 24% of octo/nonagenarians carried the KIR A haplotype and 76% KIR B haplotype with no differences for KIR A haplogroup frequency between male or female subjects (23% v 24%; p=0.88) or for KIR B haplogroup (77% v 76%; p=0.99). Octo/nonagenarian KIR A haplotype carriers showed increased NK numbers and percentage compared to Group B KIR subjects (p=0.003; p=0.016 respectively). There were no KIR A/ B haplogroup-associated changes for related CD57+CD8 (high or low) subsets. Using logistic regression, KIR B carriers were predicted to have higher IL-12 cytokine levels compared to KIR A carriers by about 3% (OR 1.03, confidence limits CI 0.99-1.09; p=0.027) and 14% higher levels for TGF-β (active), a cytokine with an anti-inflammatory role, (OR 1.14, confidence limits CI 0.99-1.09; p=0.002).

CONCLUSION

In this observational study, BELFAST octo/nonagenarians carrying KIR A haplotype showed higher NK cell numbers and percentage compared to KIR B carriers. Conversely, KIR B haplotype carriers, with genes encoding for activating KIRs, showed a tendency for higher serum pro-inflammatory cytokines compared to KIR A carriers. While the findings in this study should be considered exploratory they may serve to stimulate debate about the immune signatures of those who appear to age slowly and who represent a model for good quality survivor-hood.

Mitochondrial J haplogroup is associated with lower blood pressure and anti-oxidant status: findings in octo/nonagenarians from the BELFAST Study

Mitochondria produce cellular energy but also free-radicals, which damage cells despite an array of endogenous anti-oxidants. In Northern Europe, the mitochondrial haplogroup J has been related to longevity in nonagenarians and centenarians but also with age-related disease. Hypertension is an important contributor to atherosclerotic-related diseases and its pathogenesis is associated with increased oxidative stress. In this study, we questioned whether J haplogroup octo/nonagenarians from the Belfast Elderly Longitudinal Free-living Elderly STudy (BELFAST) study showed evidence of protective blood pressure or anti-oxidant profile which might explain their longevity advantage. Briefly, in a cross-sectional study, community-living, mentally alert (Folstein >25/30), octo/nonagenarian subjects, recruited for good health, were enlisted and consented as part of the BELFAST study, for blood pressure, anthropometric measurements and blood sampling. DNA typing for mitochondrial haplotypes was carried out with measurements for enzymatic and non-enzymatic antioxidants. J haplogroup carriers showed lower systolic blood pressure and glutathione peroxidase activity (Gpx) with higher folate measurements. There was no change in urate, bilirubin, albumin or nutrition-related antioxidants-selenium or vitamins A, C and α and β carotene. BELFAST study mtDNA J haplogroup octo/nonagenarians showed lower blood pressure and reduced glutathione peroxidase activity and higher folate, but no change for other antioxidants. These findings are of interest in view of mtDNA J haplogroup's association with increased age in some previous studies.

Blood pressure and TNF-α act synergistically to increase leucocyte CD11b adhesion molecule expression in the BELFAST study: implications for better blood pressure control in ageing

Hypertension, a key risk factor for stroke, cardiovascular disease and dementia, is associated with chronic vascular inflammation, and although poorly understood, putative mechanisms include pro-inflammatory responses induced by mechanical stretching, with cytokine release and associated up-regulated expression of adhesion molecules. Because blood pressure increases with age, we measured baseline and tumour necrosis alpha (TNF-α)-stimulated CD11b/CD18 adhesion molecule expression on leucocytes to assess any association between the two. In 38 subjects (mean age 85 years), consecutively enrolled from Belfast Elderly Longitudinal Free-Living Aging Study (BELFAST), baseline and TNF-α-stimulated CD11b/CD18 expression on separated monocytes and neutrophils increased with systolic blood pressure >120 mmHg (p = 0.05) and for lymphocytes, with diastolic blood pressure >80 mmHg (p < 0.05).These findings show increased potential stickiness of intravascular cells with increasing blood pressure which is accentuated by TNF-α, and suggest mechanistic reasons why better hypertension control is important.

Differential TERT promoter methylation and response to 5-aza-2'-deoxycytidine in acute myeloid leukemia cell lines: TERT expression, telomerase activity, telomere length, and cell death

The catalytic subunit of human telomerase (TERT) is highly expressed in cancer cells, and correlates with complex cytogenetics and disease severity in acute myeloid leukemia (AML). The TERT promoter is situated within a large CpG island, suggesting that expression is methylation-sensitive. Studies suggest a correlation between hypermethylation and TERT overexpression. We investigated the relationship between TERT promoter methylation and expression and telomerase activity in human leukemia and lymphoma cell lines. DAC-induced demethylation and cell death were observed in all three cell lines, as well as telomere shortening in HL-60 cells. DAC treatment reduced TERT expression and telomerase activity in OCI/AML3 and HL-60 cells, but not in U937 cells. Control U937 cells expressed lower levels of TERT mRNA, carried a highly methylated TERT core promoter, and proved more resistant to DAC-induced repression of TERT expression and cell death. AML patients had significantly lower methylation levels at several CpGs than "well elderly" individuals. This study, the first to investigate the relationship between TERT methylation and telomerase activity in leukemia cells, demonstrated a differential methylation pattern and response to DAC in three AML cell lines. We suggest that, although DAC treatment reduces TERT expression and telomerase activity, this is unlikely to occur via direct demethylation of the TERT promoter. However, further investigations on the regions spanning CpGs 7-12 and 14-16 may reveal valuable information regarding transcriptional regulation of TERT.

BELFAST nonagenarians: nature or nurture? Immunological, cardiovascular and genetic factors

Nonagenarians are the fastest growing sector of populations across Western European and the developed world. They are some of the oldest members of our societies and survivors of their generation and may help us understand how to age not only longer, but better.

The Belfast Longevity Group enlisted the help of 500 community-living, mobile, mentally competent, 'elite' nonagenarians, as part of an ongoing study of ageing. We assessed some immunological, cardiovascular, nutritional and genetic factors and some aspects of their interaction in this group of 'oldest old'.

Here we present some of the evidence related to genetic and nutritional factors which seem to be important for good quality ageing in nonagenarians from the Belfast Elderly Longitudinal Free-living Ageing STudy (BELFAST).