Obese individuals as thiamin storers.

OBJECTIVE

To investigate thiamin and its phosphoester content in plasma and erythrocytes for a complete picture of thiamin status in obese individuals.

DESIGN

Comparative study of the thiamin status of obese vs normal individuals.

SUBJECTS

In all, 10 healthy, overweight, fertile age women (age: 33.1+/-5.1 y; BMI: 47.0+/-0.2 kg/m(2)) and 10 normal women (age: 30.1+/-3.5 y; BMI: 22.8+/-0.2 kg/m(2)).

METHODS

a high-pressure liquid chromatography (HPLC) method for the determination of thiamin and its phosphoesters in the plasma and erythrocytes of the subjects.

RESULTS

The major findings were: (1) significant decrease of plasma thiamin, its monophosphate and total thiamin contents in obese vs normal women; (2) significant decrease of thiamin pyrophosphate ester and total thiamin content in obese vs normal women; (3) significant increase in plasma thiamin/thiamin monophosphate ratio (in practice, it was inverted) and corresponding decrease of the plasma thiamin monophosphate/erythrocytes thiamin pyrophosphate ratio in obese vs normal women, where plasma thiamin monophosphate and erythrocytes thiamin pyrophosphate contents are an index of thiamin status.

CONCLUSIONS

This study advances the hypothesis that obese women maintain higher levels of thiamin compared to normal weight subjects by storing greater amounts of thiamin in cells through preferential intracellular thiamin recycling to compensate for relatively lower levels of thiamin.