Obesity is a major public health challenge that affects almost every country in the world. People living with obesity are at increased risk of metabolic conditions, such as diabetes, hyperlipidaemia, hypertension, coronary heart disease, and non-alcoholic fatty liver disease. These metabolic conditions are known to be associated with increased mortality and increased healthcare resource utilisation (HCRU) and costs. The risk of developing metabolic conditions and associated HCRU and costs increase with body mass index (BMI). We propose this study to understand people in England living with high BMI (i.e., Class I, Class II, and Class III obesity) who have not developed metabolic conditions (i.e., metabolically healthy obesity). Specifically, we will investigate patient characteristics, clinical conditions, the risk of developing metabolic conditions or respiratory infections and mortality, and HCRU and associated costs in this population and compare between those with normal BMI and people who were overweight (but not obese).
Given the prevalence of obesity, it is of public health interest to understand the characteristics of this population and associated burden on the National Health Service in England, and to evaluate their risk of developing other severe diseases in the real-world.
Global estimates suggest 2.3 billion children and adults are overweight or obese, a trend that has increased over recent decades. The WHO released a May 2022 report on the obesity pandemic; stating 60% of Europe population are either overweight or obese, and highlighting the implications of the obesity pandemic. People living with obesity are at increased risk of metabolic conditions; including type 2 diabetes, dyslipidaemia, hypertension, coronary heart disease, non-alcoholic fatty liver disease, and respiratory infections (RTIs). People with obesity are also at risk of having multiple comorbidities associated with mortality and increased HCRU and costs. The above mentioned risks increase with BMI.
This study aims to understand the characteristics of people living with different obesity classes (I, II, and III) who are metabolically healthy, the risk of developing metabolic conditions and mortality, weight loss interventions and associated HCRU and costs in both primary and secondary care settings. Changes in obesity class will be investigated amongst a subgroup of children who reach adulthood during the study period. Propensity-score-based inverse probability of treatment weighting (IPTW) will estimate the differences between people in different obesity classes controlling for confounding factors. Descriptive analysis will be conducted for all study outcomes. Cox proportional hazard models will be used to compare the risks of developing metabolic conditions or RTIs among people in different obesity classes.
The results will provide insight into the importance of weight loss interventions in a metabolically healthy obese population and the associated benefit on the NHS in England. This is of public health interest and will allow understanding of the real-world value of weight loss interventions for obese people before developing metabolic conditions. Greater understanding of the impact of RTIs in metabolically healthy obesity patients will improve clinical awareness of priority patient groups for weight loss interventions.
Baseline comorbidities , metabolic conditions (type 2 diabetes, dyslipidaemia, hypertension, coronary heart disease, and non-alcoholic fatty liver disease), respiratory infections, mortality, weight loss interventions, inpatient admissions and length of stay, outpatient appointments, Accident and Emergency (A&E) attendances, primary care consultations, prescriptions, changes in obesity classes.
Nikolaos Fragkas - Chief Investigator - Pfizer Ltd - UK
Nick Denholm - Corresponding Applicant - Harvey Walsh Ltd
Bethany Levick - Collaborator - Harvey Walsh Ltd
Hannah Matthews - Collaborator - Harvey Walsh Ltd
John Robinson - Collaborator - Harvey Walsh Ltd
Joseph Hickey - Collaborator - OPEN Health Group
Maciej Czachorowski - Collaborator - Pfizer Ltd - UK
Mary Araghi ( Gerino ) - Collaborator - Pfizer Ltd - UK
Thozhukat Sathyapalan - Collaborator - University Of Hull
Xiaocong Marston - Collaborator - Harvey Walsh Ltd
HES Accident and Emergency;HES Admitted Patient Care;HES Outpatient;ONS Death Registration Data;Patient Level Index of Multiple Deprivation