BACKGROUND: The association between valvular heart disease and obesity is poorly documented. The present study evaluated the prevalence and worsening over time of valvular regurgitation by obesity category. METHODS: This cohort study included 11385 patients who underwent two echocardiographic examinations at least 1 year apart. Mitral, tricuspid, and aortic regurgitation were graded at the first and last visits. Regurgitation worsening was defined as those going from non/trace to moderate/severe or from moderate to severe. Frequency and worsening of regurgitant valvular heart disease were evaluated across body mass index (BMI) categories and adjusted for age, sex, follow-up time, and significant regurgitation at first exam. RESULTS: Patients aged 63 ± 15 years old at the last visit (43 % women, 29 % with obesity, median follow-up time of 3 years [interquartile range 2-6]). Valve regurgitation was more common in patients without obesity than in those with obesity across all age groups. The prevalence of mitral, tricuspid and aortic valve regurgitations at the last visit diminished for increased BMI categories: 24 %, 19 %, 16 % and 14 % for patients with normal weight, overweight, obesity and severe obesity, respectively (p <
0.002). The regurgitation worsening observed in any valve followed a similar trend: 14 %, 11 %, 9 % and 8 %, respectively (p <
0.002). These inverse associations with BMI remained significant after adjustments for cofactors. CONCLUSIONS: Obesity was associated with lower valvular regurgitation prevalence and worsening that persisted in the mitral and tricuspid valves after adjusting for confounders and excluding patients changing weight over time, suggesting the existence of an obesity paradox in valvular heart diseases.