The Open Biology Journal
2019, 7 : 14-20Published online 2019 May 31. DOI: 10.2174/1874196701907010014
Publisher ID: TOBIOJ-7-14
RESEARCH ARTICLE
Gompertz’ Hazard Law as a Network Principle of Aging
2Department of Epidemiology, Unit of Genetic Epidemiology and Bioinformatics, University of Groningen, UMC Groningen, The Netherlands
*Address correspondence to this author at the Department of Biological Psychiatry. University of Groningen UMCG, 9700 RB Groningen, The Netherlands; Tel: 031 592 541974; Email: j-korf@home.nl
ABSTRACT
Background:
Life-spanning population survivorship curves (the number of survivors versus age) are conventionally regarded as a demographic issue. Most often, the term hazard, the relative mortality per age-interval, is used as a typical survivorship parameter. Population survivorship curves are construed from cross-sectional data (single event per individual; here, mortality).
Objective:
We tested (quantitatively) how Gompertz’ law describes the mortality pattern of a wide variety of organisms, some of them fed with lifespan affecting diets. Moreover, we tested (semi-quantitatively) whether Gompertz’ law describes the disintegration of a (biological) small-world network.
Methods:
The Gompertz tests, explored in demographic data of humans (male/female) and 4 animal species (mice, honeybees, fruit flies, houseflies), were analyzed with conventional software. The Gompertz law was examined in a small-world network model.
Results:
Gompertz' law applies to all cohorts; thus, with or without exposure to experimental conditions. It describes in all cohorts old-age slowing of mortality. Gompertz’ law is compatible with a gradual and random increase of connections in the network model.
Conclusion:
Old-age deceleration of mortality is a characteristic of many populations. Aging has to be understood as a lifetime increasing of excitatory or, alternatively, of decreasing inhibitory (biological) connections, thereby facilitating pathogenic mechanisms.