Introduction: Obesity is a worldwide epidemic, Metabolic Healthy Obesity (MHO) is a vital subcohort of obesity that needs to be further investigated and epidemiologically defined. This has not received the clinical and public health attention it deserves and would help in targeting lifestyle and interventions (surgery) to those best suited.
Methods: This thesis utilised long term primary care follow up using the Clinical Practice Research Datalink (CPRD) to quantify prevalence, investigate transition, investigate all-cause mortality in the sub-cohort and study intervention outcomes in the United Kingdom.
Results: Total number of 414,522 patients were extracted, of which 231,399 (55.8%) had a body mass index (BMI) recorded. This thesis utilised 180,560 patients after exclusions. The prevalence of MHO in the UK population was 128,191/180,560 (71.0%), of which 71,485/128,191 (55.8%) remained healthy (p=<0.01) with a mean follow-up of 68.2 months. There was a 3.7% mortality rate in the MHO vs the metabolically unhealthy cohort 7.1% with an increased risk of mortality associated with a high BMI, late age at diagnosis and male gender. Frequency of bariatric surgery was generally was performed more in the metabolically healthy than unhealthy, 2.2% vs 1.9%. On Cox regression analysis, bariatric surgery remained a nonsignificant independent factor of survival within both the metabolically healthy and unhealthy obese.
Conclusion: The implication of this study is that a diagnosis of obesity as an independent factor for immediate determination of impending complications. It is imperative that the body mass index of an obese patient is laid side by side with their metabolic rate indices. On the grounds of conclusions from this thesis, further studies into the pathophysiology of metabolically unhealthy obesity are necessary, with a close reference to the presence or absence of comorbidity.