Prevalence and characteristics of individuals without diabetes and hypertension who underwent bariatric surgery: lessons learned about metabolically healthy obese.

BACKGROUND: Recent studies describe a unique subset of obese individuals with normal metabolic profiles despite having excess weight called "metabolically healthy but obese (MHO)". Our aim was to determine the prevalence of individuals without diabetes and hypertension and risk factors associated with the MHO phenotype among bariatric surgery patients.

METHODS: We conducted a retrospective study of 710 adults who underwent bariatric surgery at Johns Hopkins between 2008 and 2010. In the first analysis of 523 individuals, we identified 150 individuals without diabetes and hypertension; in the second analysis of 260 individuals, we identified 44 individuals without diabetes, hypertension and hypertriglyceridemia. We used multivariable logistic regression to examine the association between each group and potential risk factors including age, sex, race, body mass index, and presence of liver disease on liver biopsy.

RESULTS: The prevalence of individuals without diabetes and hypertension was 28.7%; among these individuals 88.7% had liver steatosis, 7.3% nonalcoholic steatohepatitis (NASH), and 19.3% liver fibrosis. These individuals were significantly more likely to be white OR=1.9 (95% CI: 1.1-3.1), younger OR=4.1 (95% CI=2.6-6.3), and female OR=2.1, (95% CI=1.2-3.6) and less likely to have liver steatosis OR=0.4 (95% CI=0.2-0.9) or NASH OR=0.3 (95% CI=0.2-0.6).

CONCLUSION: Among bariatric surgery patients, almost a third of patients do not have diabetes and hypertension and could be probably considered "MHO" and were more likely to be white, young, female, and have less liver injury. The high prevalence of liver steatosis in MHO individuals among bariatric surgery patients challenges the notion of MHO as a truly metabolically healthy entity.