Modelling the mechanisms of adipose tissue production in the long term in humans and relation to the development of obesity

A problem presented at the UK MMSG Nottingham 2006.

Presented by:
Dr James Maas (Centre for Integrative Biology, University of Nottingham)
Mr James Smith (Centre for Integrative Biology, University of Nottingham)
J Fozard, J Maas, E Norris, C Please, J Smith, D Tan, JB van den Berg, J Ward, J Wattis, H Winstanley

Problem Description

Obesity is rapidly becoming the scourge of the developed world due to its strong correlation with many associated conditions including coronary heart disease, ventricular dysfunction, congestive heart failure, stroke, cardiac arrhythmias, metabolic syndrome, type II diabetes, cardiovascular disease, sleep apnoea and osteoarthritis. In the UK, 20–25% of adults are obese, with obesity in women and men nearly tripling and quadrupling respectively between 1980 and 2002. The cost to the NHS in the year 2001–2 was approximately £1bn.

Study Group Report

We have derived models for glucose and fat metabolism over these timescales through glucagon and insulin production. Additional factors which could be incorporated into this model are the distinction between visceral fat and other fat stores, and the metabolism of protein. Features which remain to be addressed include the calibration of the model to parameter values from the literature, and characterisation of factors such as lean body mass and number of adipocytes which are agedependent and for which the model has a long memory. These factors influence the evolution of fat levels and BMI during puberty and through the rest of life. Mathematical problems which we plan to address more rigorously in future work include a rigorous averaging over the fast time scale to obtain a reduced model for the long-time kinetics of fat-production. The model could easily be extended to include factors such as appetite and insulin resistance (through allowing gI to vary slowly in time).

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