title: Prevalence and correlates of mitral valve prolapse in a population-based sample of American Indians: the Strong Heart Study.
abstract: OBJECTIVE
  Mitral valve prolapse is heritable and occurs frequently in the general population despite associations with mitral regurgitation and infective endocarditis, suggesting that selective advantages might be associated with mitral valve prolapse.
  
  
  METHODS
  Clinical examination and 2-dimensional and color Doppler echocardiography were performed in 3340 American Indian participants in the Strong Heart Study.
  
  
  RESULTS
  Mitral valve prolapse (clear-cut billowing of one or both mitral leaflets across the mitral anular plane in 2-dimensional parasternal long-axis recordings or >2-mm late systolic posterior displacement of mitral leaflets by M mode) occurred in 37 (1.8%) of 2077 women and 20 (1.6%) of 1263 men (P = 0.88); 32 (3.5%) of 907 patients with normal glucose tolerance, 11 (2.3%) of 486 patients with impaired glucose tolerance, and 13 (0.7%) of 1735 patients with diabetes (P <0.0001). Participants with mitral valve prolapse had lower mean (+/- SD) body mass index (28 +/- 5 kg/m(2) vs. 31 +/- 6 kg/m(2), P = 0.001) and blood pressure (124/71 +/- 19/10 mm Hg vs. 130/75 +/- 21/10 mm Hg, P <0.05), as well as lower levels of fasting glucose, triglycerides, serum creatinine, and log urine albumin/creatinine ratio (all P <0.001), than did those without mitral valve prolapse, although all subjects were similar in age (60 +/- 8 years). Participants with mitral valve prolapse had lower ventricular septal (0.87 +/- 0.08 cm vs. 0.93 +/- 0.13 cm) and posterior wall thicknesses (0.82 +/- 0.08 cm vs. 0.87 +/- 0.10 cm), mass (38 +/- 7 g/m(2.7) vs. 42 +/- 11 g/m(2.7)), and relative wall thickness (0.33 +/- 0.04 vs. 0.35 +/- 0.05), and increased stress-corrected midwall shortening (all P <0.01). Mitral valve prolapse was associated with a higher prevalence of mild (16 of 57 [28%] vs. 614 of 3283 [19%]) and more severe mitral regurgitation (5 of 57 [9%] vs. 48 of 3283 [1%], P <0.0001). Regression analyses showed prolapse was associated with low ventricular relative wall thickness, high midwall function, and low urine albumin/creatinine ratio, independent of age, sex, body mass index, and diabetes.
  
  
  CONCLUSIONS
  Mitral valve prolapse is fairly common and is strongly associated with mitral regurgitation in the general population. However, it is also associated with lower body weight, blood pressure, and prevalence of diabetes; a more favorable metabolic profile and ventricular geometry; and better myocardial and renal function.
authors.affiliation: Department of Medicine, New York Presbyterian Hospital-Weill Medical College, Cornell University, New York, New York, USA.
authors.forename: R B
authors.initials: RB
authors.lastname: Devereux
authors.forename: E C
authors.initials: EC
authors.lastname: Jones
authors.forename: M J
authors.initials: MJ
authors.lastname: Roman
authors.forename: B V
authors.initials: BV
authors.lastname: Howard
authors.forename: R R
authors.initials: RR
authors.lastname: Fabsitz
authors.forename: J E
authors.initials: JE
authors.lastname: Liu
authors.forename: V
authors.initials: V
authors.lastname: Palmieri
authors.forename: T K
authors.initials: TK
authors.lastname: Welty
authors.forename: E T
authors.initials: ET
authors.lastname: Lee
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D003430:Cross-Sectional Studies; D015150:Echocardiography, Doppler; D006801:Humans; D007198:Indians, North American / Q000706:statistics & numerical data*; D016014:Linear Models; D008875:Middle Aged; D008944:Mitral Valve Insufficiency / Q000453:epidemiology; D008945:Mitral Valve Prolapse / Q000000981:diagnostic imaging / Q000208:ethnology* / Q000503:physiopathology; D015995:Prevalence; D014481:United States / Q000453:epidemiology; D016277:Ventricular Function, Left