Survey of thiamine (vitamin b1) deficiency in elderly patients with decompensated congestive heart failure in Japan

Abstract Background In Japan, deficiency of thiamine (vitamin B1) in the blood occurs sporadically and can cause severe heart failure. We believe that elderly people, whose physical and social mobility is restricted, are unable to obtain a balanced intake of nutrients and are particularly susceptible to thiamine deficiency. Furthermore, there are several reports that diuretics used to treat congestive heart failure(CHF) cause thiamine to flow out of the urine, further lowering the blood concentration. Purpose The purpose of this study was to confirm the prevalence of thiamine deficiency in elderly patients with decompensated CHF who required hospitalization, the clinical characteristics of thiamine deficiency cases and the changes blood thiamine concentrations of elderly CHF cases during the acute phase. Methods This is a prospective observational study. The subjects were 248 patients aged 65 years or older who were admitted to our hospital with decompensated CHF between August 2017 and July 2020 and who provided consent to participate in the study. We measured blood thiamine concentrations at the time of admission and on the 5th-7th days of hospitalization(TC1 and TC2, respectively). We defined abnormally low thiamine level as less than 24 ng/mL, the general reference value, and classified patients into two groups: those with abnormally low TC1 values (TD-group) and those without (N-group). We investigated and compared patient backgrounds and clinical data at the time of admission for both groups. We also investigated the fluctuations in TC1 and TC2 levels in the subjects. Results The proportion of cases in the TD-group was 39%. Their average age was older than that of the N-group. Regarding clinical data, the TD-cases had higher BNP values, lower nutritional index data, and lower renal function data (Figure 1). In addition, regarding the acute phase concentration fluctuations of thiamine, TC2 was significantly lower than TC1. 82% of the TD-group's TC2 remained at abnormally low values (Figure 2). Conclusion Approximately 40% of elderly patients with decompensated congestive heart failure admitted to our facility already had abnormally low blood thiamin concentrations at the time of admission. They were older and in a state of malnutrition. Furthermore, it was confirmed that blood thiamin concentrations generally decreased further after acute treatment for congestive heart failure. It seemed very important to check blood thiamine concentrations after acute treatment of elderly patients with congestive heart failure.Figure 1 Figure 2