OBJECTIVETo investigate the effect of oral sodium selenite and vitamin E on thyroid hormones in patients with cardiovascular disease at altitude.

METHODSNinety patients with cardiovascular disease were divided into A group (n = 42, sodium selenite + VE), B group (n = 28, sodium selenite only) and control group (n = 20). Serum selenium (Se), plasma glutathione peroxidase (GSH-Px), plasma malondialdehyde (MDA) and serum T(3) and T(4) were determined before and after 6 month treatment.

RESULTSSerum Se in A and B group after 6 month treatment were higher than before [(0.71 +/- 0.22) micromol/L vs (0.31 +/- 0.17) micromol/L, (0.68 +/- 0.18) micromol/L vs (0.33 +/- 0.14) micromol/L respectively, P < 0.01], and so were plasma GSH-Px levels [(87.12 +/- 13.61) U/L vs (58.43 +/- 18.93) U/L, (84.79 +/- 12.13) U/L vs (57.12 +/- 17.36) U/L respectively] while plasma MDA were lower than before [(4.86 +/- 1.18) nmol/ml vs (8.66 +/- 0.96) nmol/ml, (4.18 +/- 1.23) nmol/ml vs (8.71 +/- 0.87) nmol/ml respectively, P < 0.01]. Serum T(3) and T(4) levels in A and B group were also obviously decreased (P < 0.01). The levels of plasma GSH-Px were positively correlated with those of serum Se (r = 0.781, P < 0.01). The levels of plasma MDA and serum T(3) and T(4) were negatively correlated with those of serum Se (r = -0.385, -0.687, -0.412 respectively, P < 0.05). 31 cases (73.81%) in A group and 20 cases (71.42%) in B group completely recovered to normal; 4 cases (9.52%) in A group and 2 cases (7.43%) in B group partly recovered. The recovered rates were significantly different from that of control (P < 0.05).

CONCLUSIONSupplementation of adequate selenium may correct the abnormal function of secretion in thyroid hormones of patients because of lack of selenium at altitude areas.