title: Thyroid function status and echocardiographic abnormalities in patients with Beta thalassemia major in bahrain.
abstract: BACKGROUND
  Thyroid gland dysfunction and echocardiographic cardiac abnormalities are well-documented in patients with transfusion dependent beta-thalassemia major (β-TM).
  
  
  OBJECTIVE
  This cross-sectional analytic study was conducted to investigate left ventricle (LV) diastolic and systolic function using pulsed Doppler (PD) and tissue Doppler (TD) echocardiography and correlate that with serum level thyroid stimulating hormone in patients with β-TM.
  
  
  METHODS
  The study was conducted on patients with β-TM (n = 110, age 15.9 ± 8.9 years) and compared with a control group (n = 109, age 15.8 ± 8.9 years). In all participants, echocardiographic indices of PD and TD were performed and blood samples were withdrawn for measuring the serum level of TSH, free T4, and ferritin. A linear regression analysis was performed on TSH level as the dependent variable and serum ferritin as independent. Stepwise multiple regression analysis was used to determine the odds ratio of different biochemical and echo variables on the risk of developing hypothyroidism.
  
  
  RESULTS
  Patients with β-TM compared with controls had thicker LV septal wall index (0.65 ± 0.26 vs. 0.44 ± 0.21 cm/M(2), P < 0.001), posterior wall index (0.65 ± 0.23 vs. 0.43 ± 0.21 cm/m(2), P < 0.01) and larger LVEDD index (4.35 ± 0.69 vs.3.88 ± 0.153 mm/m(2), P < 0.001). In addition, β-TM patients had higher transmitral E wave velocity (E) (70.81 ± 10.13 vs. 57.53 ± 10.13 cm/s, P = 0.02) and E/A ratio (1.54 ± 0.18 vs. 1.23 ± 0.17, P < 0.01) and shorter deceleration time (DT) (170.53 ± 13.3 vs. 210.50 ± 19.20 m sec, P < 0.01). Furthermore, the ratio of transmitral E wave velocity to the tissue Doppler E wave at the basal septal mitral annulus (E/Em) was significantly higher in the β-TM group (19.68 ± 2.81 vs. 13.86 ± 1.41, P < 0.05). The tissue Doppler systolic wave (Sm) velocity and the early diastolic wave (Em) were significantly lower in the β-TM group compared with controls with Sm, 4.82 ± 1.2 vs. 6.22 ± 2.1 mm/sec, P < 0.05 and (Em), 3.51 ± 2.7 vs. 4.12 ± 2.5 mm/sec. P < 0.05, respectively). The tricuspid valve velocity was significantly higher in β-TM patients compared with controls 2.85 ± 0.56 vs. 1.743 ± 0.47 m sec, respectively, P < 0.01). The prevalence of subclinical hypothyroidism in patients with β-TM was 15.4%, with significantly higher mean serum TSH compared with controls (6.78 ± 1.5 vs. 3.10 ± 1.02 μIU/mL, P < 0.01) and positively correlated with the serum ferritin level (r = 0.34, P = 0.014). On multiple regression analysis, the LV mass, LVEF%, and E/A ratio were not positive predictors of hypothyroidism in patients with β-TM.
  
  
  CONCLUSIONS
  We conclude that patients with β-TM had a high prevalence of subclinical hypothyroidism of 15.4%. Thyroid stimulating hormone was significantly high and positively correlated with the serum ferritin level. Echo cardiographic pulsed Doppler showed a restrictive LV diastolic pattern suggestive of severe diastolic dysfunction with preserved left ventricle systolic function.
authors: Cardiac Unit, Salmaniya Medical Complex, Ministry of Health, Kingdom of Bahrain. ; Department of Family and Community Medicine, College of Medicine and Medical Sciences, Arabian Gulf University, Kingdom of Bahrain.
authors: Taysir S
authors: TS
authors: Garadah
authors: Najat A
authors: NA
authors: Mahdi
authors: Ahmed M
authors: AM
authors: Jaradat
authors: Zuheir A
authors: ZA
authors: Hasan
authors: Das S
authors: DS
authors: Nagalla
keywords: Bahrain; beta-thalassemia major; pulsed echo Doppler; thyroid stimulating hormone; tissue Doppler echocardiography
references: Circulation. 1993 Jul;88(1):146-55
references: 8319326
references: Eur J Echocardiogr. 2002 Mar;3(1):47-51
references: 12067534
references: J Cardiol. 2003 Apr;41(4):175-82
references: 12728538
references: J Am Coll Cardiol. 2007 May 15;49(19):1903-14
references: 17498573
references: Thyroid. 2002 Feb;12(2):151-4
references: 11916284
references: J Am Soc Echocardiogr. 1998 Dec;11(12):1106-12
references: 9923990
references: Ann Hematol. 2007 Jun;86(6):429-34
references: 17262191
references: Nihon Rinsho. 1996 Sep;54(9):2454-9
references: 8890578
references: J Clin Endocrinol Metab. 1993 Feb;76(2):357-61
references: 8432779
references: Haematologica. 2004 Oct;89(10):1187-93
references: 15477202
references: Arch Dis Child. 1994 Aug;71(2):128-32
references: 7944532
references: J Pediatr Endocrinol Metab. 2000 Jun;13(6):651-6
references: 10905390
references: J Am Coll Cardiol. 1997 Nov 15;30(6):1527-33
references: 9362412
references: Blood. 1990 Aug 1;76(3):435-44
references: 2198956
references: J Trop Pediatr. 2002 Feb;48(1):50-4
references: 11866338
references: Circulation. 1990 Jul;82(1):88-94
references: 2364528
references: Circulation. 1978 Dec;58(6):1072-83
references: 709763
references: Turk J Pediatr. 1998 Apr-Jun;40(2):201-9
references: 9677725
references: Circulation. 2000 Oct 10;102(15):1788-94
references: 11023933
references: J Am Coll Cardiol. 1987 Oct;10(4):800-8
references: 2958532
references: Ann Hematol. 2000 Jan;79(1):7-12
references: 10663615
references: Am J Cardiol. 1986 Feb 15;57(6):450-8
references: 2936235
references: Ann N Y Acad Sci. 1980;344:397-404
references: 6930879
references: J Pediatr Endocrinol Metab. 2006 Apr;19(4):471-80
references: 16759032
references: Heart. 2003 Jul;89(7):762-6
references: 12807852
references: J Clin Endocrinol Metab. 1984 Apr;58(4):667-70
references: 6321534