Association of Body Mass Index with Aortic Stenosis in Metabolically Healthy Obese

Aim: To explore the association between aortic stenosis and obesity according to body mass index (BMI) among a metabolically healthy population.

Methods: A retrospective analysis was performed on all metabolically healthy patients, defined as lack of known diabetes mellitus, hypertension, and hyperlipidemia, who underwent echocardiography between 2011 and 2016 during hospitalization in our medical center, and had available BMI data. Exclusion criteria included advanced renal disease and very low or high BMI. Patients were divided into groups according to BMI - normal BMI (18.5-25 kg/m²), overweight (25.01-30 kg/m²), obese (30.01-35 kg/m²), and morbidly obese (>35 kg/m²).

Results: The cohort consisted of 4975 patients with a mean age of 56 years, 58.8% of male gender, and mean BMI 26.2 kg/m². Comorbidities did not differ significantly between the groups. Severe AS was found in 4.4%, 5.4%, 5.9%, and 6% of patients with normal BMI, overweight, obese, and morbidly obese, respectively (p=0.001). Higher BMIs demonstrated an increased risk for having aortic valve area (AVA) index2/m² (p=0.042) and aortic valve peak pressure>60 mmHg (p=0.024). After adjustments for age and gender, every rise in BMI unit increased the risk for having AVA index2/m² by 7 percent (OR 1.07, 95%CI 1.02-1.11, p=0.002) and aortic valve peak pressure>60 mmHg by 6 percent (OR 1.06, 95%CI 1.01-1.1, p=0.008). However, the relation remained significant only among patients under 65 years of age.

Conclusion: Metabolically healthy obese were at risk for aortic stenosis. The association was obscured by the impact of aging amongst patients over 65 years.