title: Obesity and its association to phenotype and clinical course in hypertrophic cardiomyopathy.
abstract: OBJECTIVE
  This study sought to assess the impact of body mass index (BMI) on cardiac phenotypic and clinical course in a multicenter hypertrophic cardiomyopathy (HCM) cohort.
  
  
  BACKGROUND
  It is unresolved whether clinical variables promoting left ventricular (LV) hypertrophy in the general population, such as obesity, may influence cardiac phenotypic and clinical course in patients with HCM.
  
  
  METHODS
  In 275 adult HCM patients (age 48 ± 14 years; 70% male), we assessed the relation of BMI to LV mass, determined by cardiovascular magnetic resonance (CMR) and heart failure progression.
  
  
  RESULTS
  At multivariate analysis, BMI proved independently associated with the magnitude of hypertrophy: pre-obese and obese HCM patients (BMI 25 to 30 kg/m(2) and >30 kg/m(2), respectively) showed a 65% and 310% increased likelihood of an LV mass in the highest quartile (>120 g/m(2)), compared with normal weight patients (BMI <25 kg/m(2); hazard ratio [HR]: 1.65; 95% confidence interval [CI]: 0.73 to 3.74, p = 0.22 and 3.1; 95% CI: 1.42 to 6.86, p = 0.004, respectively). Other features associated with LV mass >120 g/m(2) were LV outflow obstruction (HR: 4.9; 95% CI: 2.4 to 9.8; p < 0.001), systemic hypertension (HR: 2.2; 95% CI: 1.1 to 4.5; p = 0.026), and male sex (HR: 2.1; 95% CI: 0.9 to 4.7; p = 0.083). During a median follow-up of 3.7 years (interquartile range: 2.5 to 5.3), obese patients showed an HR of 3.6 (95% CI: 1.2 to 10.7, p = 0.02) for developing New York Heart Association (NYHA) functional class III to IV symptoms compared to nonobese patients, independent of outflow obstruction. Noticeably, the proportion of patients in NYHA functional class III at the end of follow-up was 13% among obese patients, compared with 6% among those of normal weight (p = 0.03).
  
  
  CONCLUSIONS
  In HCM patients, extrinsic factors such as obesity are independently associated with increase in LV mass and may dictate progression of heart failure symptoms.
authors: Referral Center for Myocardial Diseases, Azienda Ospedaliera Universitaria Careggi, Florence, Italy. olivottoi@aou-careggi.toscana.it
authors: Iacopo
authors: I
authors: Olivotto
authors: Barry J
authors: BJ
authors: Maron
authors: Benedetta
authors: B
authors: Tomberli
authors: Evan
authors: E
authors: Appelbaum
authors: Carol
authors: C
authors: Salton
authors: Tammy S
authors: TS
authors: Haas
authors: C Michael
authors: CM
authors: Gibson
authors: Stefano
authors: S
authors: Nistri
authors: Eleonora
authors: E
authors: Servettini
authors: Raymond H
authors: RH
authors: Chan
authors: James E
authors: JE
authors: Udelson
authors: John R
authors: JR
authors: Lesser
authors: Franco
authors: F
authors: Cecchi
authors: Warren J
authors: WJ
authors: Manning
authors: Martin S
authors: MS
authors: Maron
mesh_terms: D000328:Adult; D015992:Body Mass Index; D002312:Cardiomyopathy, Hypertrophic / Q000453:epidemiology*; D015331:Cohort Studies; D003924:Diabetes Mellitus, Type 2 / Q000453:epidemiology; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006333:Heart Failure / Q000145:classification / Q000453:epidemiology*; D006352:Heart Ventricles / Q000473:pathology; D006801:Humans; D006973:Hypertension / Q000453:epidemiology; D007558:Italy / Q000453:epidemiology; D016013:Likelihood Functions; D019028:Magnetic Resonance Imaging, Cine; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009765:Obesity / Q000453:epidemiology*; D010641:Phenotype; D012737:Sex Factors; D014481:United States / Q000453:epidemiology; D014694:Ventricular Outflow Obstruction / Q000453:epidemiology
keywords: BMI; CMR; HCM; HR; LGE; LV; LVH; NYHA; New York Heart Association; body mass index; cardiac magnetic resonance; cardiovascular magnetic resonance; hazard ratio; hypertrophic cardiomyopathy; hypertrophy; late gadolinium enhancement; left ventricular; left ventricular hypertrophy; obesity; outcome