People living with obesity face an increased risk of a large variety of comorbidities. Previous studies have examined how obesity is associated with an increased risk of comorbidities, but it is not well described how various levels of weight loss associate with a reduction in the risk of developing these obesity related complications.
With this study we will investigate how different degrees of weight loss (for instance 5, 10, 20, or 30% of the body weight) associate with a reduction in the risk of developing selected obesity related complications in adults living with obesity. The selected outcomes are complications such as high blood pressure, Type 2 diabetes, sleep apnoea (a sleep disorder in which breathing repeatedly stops and starts), asthma, different kinds of cardiovascular events and depression.
Specifically, we will investigate whether a weight loss in the range from five to 50 percent of the body weight associates with a reduction in the risk of developing obesity related complications and whether the associations change with BMI before the weight loss. We will further examine whether the associations are the same for different age-groups, between genders and across different ethnicities.
If weight loss is associated with a clinically relevant reduction in the risk for developing these outcomes, the study will put attention to the importance of and health benefits from a weight loss. This can guide and motivate patients and health care professionals to initiate a lifestyle change or other types of treatment for individuals with obesity.
In a recent study using data from the UK CPRD and Hospital Episode Statistics (HES), we have shown that an intentional median 13% weight loss was associated with a risk reduction for type 2 diabetes (T2D) (40%), sleep apnoea (40%), hypertension (22%), dyslipidaemia (19%) and asthma (18%), when compared to keeping a high stable weight.
In this study we will examine how different degrees of weight loss (via behavioural changes, anti-obesity medication or bariatric surgery) among adults with obesity may translate into health benefits. In a prospective cohort design we will investigate the associations between weight loss between 5-50% and onset of 13 selected obesity related complications. We will examine if associations differ by initial BMI (e.g. 30,40 or 50 kg/m2) and how the associations differ with different obesity related complications.
We will include adults (18-70 years of age) who have a BMI record between January 2001 and December 2010, and a subsequent BMI record during year 4. Given the mean BMI during year 1 and the observed change between year 1 to 4, we will use Cox proportional hazard models to estimate the association between weight loss and the obesity related complications that occur after the four year baseline period: T2D, sleep apnoea, hip/knee osteoarthritis, hypertension, dyslipidaemia, unstable angina/myocardial infarction (MI; composite endpoint), venous thromboembolism, asthma, atrial fibrillation, heart failure, chronic kidney disease (CKD), polycystic ovary syndrome (PCOS) and depression. Underlying time scale is calendar time.
Analyses will be adjusted for: Index BMI, age, sex, smoking, ethnicity, socioeconomic status and baseline comorbidities.
We hypothesize that a weight loss will decrease the hazard ratio of obesity related complications.
The intended public health benefit is that the results can guide and motivate patients and health care professionals to initiate a lifestyle change or other types of treatment for individuals with obesity.
Time to diagnosis with one of the following selected outcomes during follow-up:
1) T2D; 2) sleep apnoea; 3) hip/knee osteoarthritis; 4) hypertension; 5) dyslipidaemia; 6) unstable angina/MI (composite endpoint); 7) asthma; 8) atrial fibrillation; 9) heart failure; 10) venous thromboembolism; 11) CKD; 12) PCOS and 13) depression.
Camilla Morgen - Chief Investigator - Novo Nordisk A/S
Camilla Morgen - Corresponding Applicant - Novo Nordisk A/S
Anette Varbo - Collaborator - Novo Nordisk A/S
Christiane L Haase - Collaborator - Novo Nordisk A/S
Kamlesh Khunti - Collaborator - University of Leicester
Kasper Matthiessen - Collaborator - Novo Nordisk A/S
Naveen Rathor - Collaborator - Novo Nordisk A/S
Volker Schnecke - Collaborator - Novo Nordisk A/S
HES Admitted Patient Care;ONS Death Registration Data;Patient Level Index of Multiple Deprivation