Thiamine deficiency in congestive heart failure patients receiving long term furosemide therapy.

OBJECTIVE

To assess the presence of thiamine deficiency in congestive heart failure patients receiving furosemide therapy.

DESIGN

Prospective, biochemical analysis of thiamine status was performed in outpatients and inpatients of the University of Ottawa Heart Institute.

SUBJECTS

Thirty-two patients with congestive heart failure who received at least 40 mg/day of furosemide were included. Patients were then separated into two groups depending on whether the dose of furosemide was greater than or equal to 80 mg/day.

METHODS

The primary measure was actual thiamine status as assessed by the erythrocyte transketolase enzyme activity and the degree of thiamine pyrophosphate effect.

RESULTS

Biochemical evidence of severe thiamine deficiency was found in 98% (24 of 25) patients receiving at least 80 mg/day of furosemide and in 57% (four of seven) of patients taking 40 mg furosemide daily, odds ratio (OR) 19.0 (1.13<OR<601.29). Thiamine status was not associated with any other clinical variables.

CONCLUSIONS

These findings suggest that thiamine deficiency occurs in a substantial proportion of congestive heart failure patients being treated with furosemide.