Kleiber′s law and the A 1 chieve study

Abstract

Kleiber's law is a near-universal maxim of biology. Being one of the allometric scaling laws, this 3/4 power law for metabolic rates is characteristic of all organisms, and states that as the size of a living organism grows, its life span increases, and heart beat reduces by three-fourth square. Simply put, it means that an elephant, which is x times larger than a mouse, has an x¾ heart rate as compared to its murine friend. Identified by Kleiber in the 1930s, while working on comparative animal physiology, this law has since been found to hold true in a wide variety of situations, including plants and bacteria.[1] An even more surprising finding, however, has been the discovery of situations where Kleiber's law holds true in inverse. When studying urban environments, Bettencourt et al. realized that human social organizations are extensions of biology, following similar principles and constraints as well. Cities obey this law as well, but sometimes with a positive rather than negative scaling correlation. As group of people grow in number, its original or creative or scientific output expands, not linearly, but exponentially, as its 5/4th power. To paraphrase in simple words, if n scientists produce x publications, 2n researchers will produce, not 2n, but 2n5/4 papers. This superlinear scaling is applicable to almost all sociological organization, including creation of patents and inventions.[2] Though the versatility of this seemingly elementary law has been criticized, this observation is important from a diabetology and endocrinology perspective. The world is experiencing an unprecedented pandemic of lifestyle diseases with diabetes being the most visible face. This surge in incidenceand prevalence of diabetes is matched by an increase in the number of scientific publications related to this condition. A search on PubMed or Google scholar reveals a virtual explosion in the number and size of clinical trials in diabetes. However, none of these trials compares in magnitude with the A1chieve trial. The A1chieve study has set new landmarks in clinical research in terms of number of continents, countries, clinical sites, subjects and insulins that have been studied.[3] The enormity of this observational trial is reflected in the data that has been published related to this study. Prestigious international journals such as Diabetes Research and Clinical Practice (DRCP) and premier opinion-building Indian publications like Journal of Association of Physicians of India (JAPI) have devoted special issues to A1chieve. As Dr. Siddharth Shah, editor JAPI, clarifies: “We have responsibility to publish, with an obligation towards the participants and the investigators.”[4] But back to the Kleiber's Law. The cross-country, multi-insulin nature of this trial and the wide spectrum of data collected over an appreciably long time contribute to the robust nature of A1chieve results. Put together, all this data should result in superlinear scaling of energy rather synergy amongst all stakeholders. This issue of Indian J Endocrinology Metabolism should foster an understanding of our short comings and an appreciation of the effective, safe and well-tolerated insulin analogues available to us. More importantly, it should act as a stimulus for bench marking and experience sharing among different clinical practices, regions and countries. In this manner, the A1chieve study and the Indian Journal of Endocrinology and Metabolism should lay the ground for a superlinear improvement in the quality of diabetes care throughout the world.