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Analysis of the genetic contribution to the persistent resistance to an obesogenic lifestyle influence on BMI

Mislej, Jerneja (2017) BINP30 20171
Degree Projects in Bioinformatics
Abstract
Obesity has reached epidemic proportions in high-income countries during the last decades. At a population level, the speed of the progression of this epidemic indicates that lifestyle changes are a major contributor to the rising obesity rates. However, a part of the population has remained lean despite being exposed to obesogenic lifestyles.
The objectives of this master thesis project are i) to characterize the persistent resistance to an obesogenic lifestyle influence on BMI and ii) to estimate the genetic influence on this phenotype. The project is based on the extensive collection of lifestyle, clinical, and genetic data available within a northern-Swedish population-based prospective cohort study: Västerbotten Health Survey (VHU).... (More)
Obesity has reached epidemic proportions in high-income countries during the last decades. At a population level, the speed of the progression of this epidemic indicates that lifestyle changes are a major contributor to the rising obesity rates. However, a part of the population has remained lean despite being exposed to obesogenic lifestyles.
The objectives of this master thesis project are i) to characterize the persistent resistance to an obesogenic lifestyle influence on BMI and ii) to estimate the genetic influence on this phenotype. The project is based on the extensive collection of lifestyle, clinical, and genetic data available within a northern-Swedish population-based prospective cohort study: Västerbotten Health Survey (VHU). Lifestyle and clinical data from VHU was used to derive the phenotype of persistent resistance to an obesogenic lifestyle influence on BMI, while the genetic data was used to estimate the proportion of phenotypic variance attributable to genetic variation.
By switching the focus from subjects, whose weight increases more or as expected according to their lifestyle, to subjects who are persistently resistant to lifestyle induced weight gain, protective characteristics against obesity could be explored and established. (Less)
Popular Abstract
Protective genetics against obesity

In the last decades, substantial changes in the lifestyle have led to a high prevalence of obesity in high-income countries. However, a part of the population has remained lean despite being exposed to obesogenic lifestyles. Characterizing the genetic factors associated to resistance to obesogenic lifestyles might be informative for the prevention of obesity.

This master’s project was based on an extensive collection of lifestyle, clinical, and genetic data available within a northern-Swedish population-based cohort. Lifestyle and clinical data were used to characterize a person’s persistent resistance to an obesogenic lifestyle, while the genetic data was used to estimate the proportion of the... (More)
Protective genetics against obesity

In the last decades, substantial changes in the lifestyle have led to a high prevalence of obesity in high-income countries. However, a part of the population has remained lean despite being exposed to obesogenic lifestyles. Characterizing the genetic factors associated to resistance to obesogenic lifestyles might be informative for the prevention of obesity.

This master’s project was based on an extensive collection of lifestyle, clinical, and genetic data available within a northern-Swedish population-based cohort. Lifestyle and clinical data were used to characterize a person’s persistent resistance to an obesogenic lifestyle, while the genetic data was used to estimate the proportion of the persistent resistance variance attributable to genetic variation (known as a heritability).

Exposure to an obesogenic diet and a lack of physical activity were analysed in order to assess the influence of such a lifestyle on the Body Mass Index (BMI: a person’s weight in kilograms divided by person's height in meters squared) in the study sample of the current project. By estimating the expected BMI response to established obesogenic factors, participants with a BMI that deviates from the predicted level, given their lifestyle, can be identified and used to characterize persistent resistance to an obesogenic lifestyle.

Lifestyle, phenotypic* and genetic data were explored and analysed within a northern Swedish population-based cohort of approximately one hundred thousand participants, aged between 40 and 60. The trends in the obesogenic lifestyle influence on the BMI were visualised and modelled with statistical analyses. The degree of genetic variation affecting the variability of the difference between the predicted BMI and the observed BMI, was assessed in order to estimate the heritability of persistent resistance phenotype.

A relatively large proportion of variance was estimated to be attributable to genetic variation, for both resistance and susceptibility to an obesogenic lifestyle. The degree of genetic contribution to the persistent resistance of the BMI response to an obesogenic lifestyle motivates future exploration and identification of genetic variants that protect against obesity, where the data analysis pipeline can be easily extended to include a Genome-Wide Association Study (GWAS*).

*Glossary:
Phenotype refers to observable physical properties or disease of an individual, i.e. height, weight, BMI, or diabetes, obesity, etc. It is a consequence of the interaction of individual’s genotype and the environment.
GWAS is a statistical method that searches the genome for small genetic variants, called single nucleotide polymorphisms (SNPs) that occur more frequently in individuals with a particular phenotype/disease than in individuals without the phenotype/disease.


Master’s Degree Project in Bioinformatics 30 credits 2017
Department of Biology, Lund University

Supervisor: Alaitz Poveda, Genetic and Molecular Epidemiology Unit, Department of Clinical Sciences, Lund University Diabetes Center
Co-supervisors: Azra Kurbasic, Paul W. Franks, Genetic and Molecular Epidemiology Unit, Department (Less)
Please use this url to cite or link to this publication:
author
Mislej, Jerneja
supervisor
organization
course
BINP30 20171
year
type
H2 - Master's Degree (Two Years)
subject
language
English
id
8929162
date added to LUP
2017-12-06 10:04:04
date last changed
2017-12-06 10:04:04
@misc{8929162,
  abstract     = {Obesity has reached epidemic proportions in high-income countries during the last decades. At a population level, the speed of the progression of this epidemic indicates that lifestyle changes are a major contributor to the rising obesity rates. However, a part of the population has remained lean despite being exposed to obesogenic lifestyles.
The objectives of this master thesis project are i) to characterize the persistent resistance to an obesogenic lifestyle influence on BMI and ii) to estimate the genetic influence on this phenotype. The project is based on the extensive collection of lifestyle, clinical, and genetic data available within a northern-Swedish population-based prospective cohort study: Västerbotten Health Survey (VHU). Lifestyle and clinical data from VHU was used to derive the phenotype of persistent resistance to an obesogenic lifestyle influence on BMI, while the genetic data was used to estimate the proportion of phenotypic variance attributable to genetic variation.
By switching the focus from subjects, whose weight increases more or as expected according to their lifestyle, to subjects who are persistently resistant to lifestyle induced weight gain, protective characteristics against obesity could be explored and established.},
  author       = {Mislej, Jerneja},
  language     = {eng},
  note         = {Student Paper},
  title        = {Analysis of the genetic contribution to the persistent resistance to an obesogenic lifestyle influence on BMI},
  year         = {2017},
}