Ageing: definitions, mechanisms and the magnitude of the problem

doi:10.1053/bega.2001.0244

Best Practice & Research Clinical Gastroenterology

Volume 15, Issue 6, December 2001, Pages 835-849

https://doi.org/10.1053/bega.2001.0244 Get rights and content

Abstract

All multi-cellular organisms undergo change with time. Conception heralds the onset of growth and development, leading to reproductive competence and propagation of the species. With time, organisms age, leading to death as a final end-point. Whilst our knowledge and definitions of growth and reproduction are firmly established, the concept of ageing remains less well understood. One of the reasons for the lack of a singular definition of ageing is that it can be considered in many different ways, according to social, behavioural, physiological, morphological, cellular and molecular changes. Research has led to a number of theories being proposed that may explain the ageing process. In this chapter, we will review some of these theories and address some of the following fundamental questions: What is ageing? How can ageing be measured? When does ageing begin? When is an organism defined as old?

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Citation Excerpt :
A wide number of theories have been proposed over the past decades (Medvedev, 1990), ranging from the accumulation of damage to the biological programmed aging. It is widely accepted, however, that theories from both categories are not necessarily exclusive, and aging is regarded as a complex, multifactorial process driven by both intrinsic (genetic) and extrinsic (environmental) factors (Balcombe and Sinclair, 2001; Medvedev, 1990). Recent reviews of the aging process integrate many different theories in a global perspective.
Fat is historically associated with poor health and obesity. However, the continuous use of lipidomics and genetic studies in model organisms revealed that specific lipid profiles and signals might delay aging. In order to identify and quantify the lipid species, researchers are taking advantage of the recent developments in the area of lipidomics that is mainly done by mass spectrometry and further techniques, such as NMR spectroscopy and chromatographic separations.
This review will emphasize the role of lipid composition and metabolism during aging. We review the molecular and physiological changes during the progression of aging with a special focus on the role of lipids. Interventions to modulate life span in a variety of organisms such caloric restriction, show a significant extension of their maximum life-span and a decrease in the onset of age-related diseases. In particular, the influence of dietary restriction in lipid metabolism will be a major point of this review.
Combined exercise is a modality for improving insulin resistance and aging-related hormone biomarkers in elderly Korean women
2018, Experimental Gerontology
Citation Excerpt :
DHEA-S, a steroid hormone secreted by the adrenal gland in an esterified form, is converted to androgen, a male hormone, and estrogen, a female hormone, in the peripheral tissues. A reduction in DHEA-S levels causes increased susceptibility to cancer, atherosclerosis, brain damage, and insulin resistance (Balcombe and Sinclair, 2001; Kell, 2011). During menopause, a unique transition stage of the endocrine system, the estrogen level decreases, thus causing a reduction in the fat-free mass index and BMR (Munsell et al., 2014; Lovejoy et al., 2008).
The functional decline of the endocrine and immune systems with aging causes changes in the regulation of the body's metabolism and defense functions. Although it is impossible to stop aging artificially, regular exercises reportedly delay aging and have positive effects on senile diseases. The improvements in insulin resistance values and aging-related hormones in elderly women after combined exercises have not been effectively elucidated.
In this study, we aimed to examine the impact of combined exercise on insulin resistance and aging-related hormones in elderly women.
Twenty elderly Korean women were randomly assigned to a “non-exercise” (n = 10) or combined exercise group (n = 10). The exercise group performed both anaerobic and aerobic exercises for 12 weeks, three times per week. Exercise intensity was increased gradually, from 40% to 70% of the heart rate reserve (HRR) every 3 weeks. Insulin resistance, growth hormone, IGF-1, DHEA-S, and estrogen were measured before and after the 12-week intervention.
The main effect was found in the glucose level for a time, which significantly decreased in the exercise group. The insulin level and HOMA-IR showed significant interaction effects and increased significantly in the control group. The GH level showed significant interaction effects and increased significantly in the exercise group. The IGF-1 level showed significant interaction effects, but not significantly within and between groups. The DHEA-S level revealed interaction effects and the main effect for a time and significantly increased in the exercise group. The estrogen level exhibited an interaction effect and increased significantly in the exercise group. After the 12-week combined exercise intervention, no significant difference was observed between groups.
This study has shown that 12-week combined exercise is useful for improving insulin resistance and GH, IGF-1, and DHEA-S levels in elderly women. Thus, this study provides evidence that combined exercise is a useful therapeutic method to decrease insulin resistance and stimulate the secretion of aging-related hormones in elderly women.

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^f1: All Correspondence to: Dr N.R. Balcombe, 1 Brewers Close, Binley, Coventry, CV3 2UP, UK, Tel: 07968 111 470; E-mail: [email protected]

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Regular ArticleAgeing: definitions, mechanisms and the magnitude of the problem

Abstract

Experimental Cell Research

Progress in Brain Research

Experimental Gerontology

International Review of Connective Tissue Research

Experimental Molecular Pathology

Lancet

Journal of Nutrition

Journal of Theoretical Biology

Cell

Experimental Gerontology

Journal of Theoretical Biology

Experimental Cell Research

Advances in Genetics

Journal of Insect Physiology

An Unsolved Problem in Biology

On the nature and function expressive of the law of human mortality and on a new mode of determining life contingencies

Philosophical Transactions of the Royal Society of Medicine

The Social Medicine of Old Age

The Biology of Senescence

Time, Cells and Ageing

Cato major; or, His Discourse of Old Age

A Theory of Cognitive Ageing

Motivation reconsidered: The concept of competence

Psychological Review

Ageing, natural death and the compression of morbidity

New England Journal of Medicine

Using Healthy Active Life Expectancy to measure population outcomes

Outcomes Assessment for Healthcare in Elderly People

Human ageing: usual and successful

Science

Heterochromic transplantation in the study of ageing

Proceedings of the Royal Society of Biologists

Cytogerontology since 1881: a reappraisal of August Weismann and a review of modern progress

Human Genetics

Replicative lifespan of cultivated human cells: effects of donor's age, tissue and genotype

Laboratory Investigation

Evidence for a relationship between longevity of mammalian species and lifespans of normal fibroblasts in vitro and erythrocytes in vivo

Proceedings of the National Academy of Sciences of the USA

Genetic effects on the longevity of cultured human fibroblasts. I. Werner's syndrome

Gerontology

On the histochemistry and ultrastructure of age-pigment

Advances in Gerontology Research

Cellular ageing: postreplicative cells. A review (Part II)

American Journal of Pathology

Lipoprotein pigments; their relationship to ageing in the human nervous system. I. The lipofusicn content of nerve cells

Brain

The relationship between ageing and cancer: somatic mutations or breakdown of host defence mechanisms

Swiss Bulletin of Academic Medicine

Lack of increase in DNA cross-linking in Drosophila melanogaster with age

Gerontologia, Basel

Temporal changes in collagen-ageing or essential maturation

Advances in the Biology of the Skin—Ageing

Regular Article
Ageing: definitions, mechanisms and the magnitude of the problem