Reduced thiamine phosphate, but not thiamine diphosphate, in erythrocytes in elderly patients with congestive heart failure treated with furosemide

Objectives. To measure the concentrations of thiamine and thiamine esters by high-pressure liquid chromatography (HPLC) in elderly patients treated with furosemide for heart failure and in a control group. Design. A cross-sectional study of blood thiamine and thiamine ester concentrations. Subjects. Forty-one patients admitted to hospital for heart failure and 34 elderly living at home. No vitamin supplementation was allowed. Results. Compared with the healthy controls, furosemide-treated patients had significantly reduced whole blood thiamine phosphate (TP; 4.4 +/- 2.2 vs. 7.6 +/- 2.0 nmol L-1) and thiamine diphosphate (TPP; 76 +/- 21.5 vs. 91 +/- 19.8 nmol L-1) (mean +/- SD). When the thiamine concentrations were related to the haemoglobin concentrations, which were reduced in the heart failure patients, the levels of TP (nmol g(-1) Hb) were 0.38 +/- 0.26 vs. 0.54 +/- 0.17 (P < 0.0001), and of TPP were 6.35 +/- 1.76 vs. 6.37 +/- 1.29 (P = 0.95). There were no differences in T and TP concentrations in plasma between the two groups. Conclusions. The elderly patients with heart failure treated with furosemide have not reduced the storage form of thiamine, TPP, but only TP. This change is most likely not an expression of a thiamine deficiency, but rather of an altered metabolism of thiamine, which is not understood at present.