A Systematic Review of Thiamine Supplementation in Improving Diabetes and Its Related Cardiovascular Dysfunction

Abstract

The significance of thiamine in human health is linked to its role in several pathways that control different disease processes. Significant improvements in cardiometabolic diseases, substantially impacted by thiamine imbalances, are observed with thiamine supplementation. Diabetic patients could see a reduction in cardiovascular (CV) risk due to thiamine's significant impact on glucose metabolism. Specifically, increased ventricular filling pressures and oxygen consumption, indicative of CV dysfunction, are caused by oxidative and inflammatory damage to blood vessels, diabetic nephropathy, and elevated lactic acid production. Despite promising pre-clinical results for thiamine, clinical trials have yielded conflicting and contradictory findings due to limitations like small sample sizes and insufficient follow-up. To provide a summary of clinical study results, this systematic review assessed the impact of thiamine supplementation on diabetes and its CV complications. The studies included in this systematic review were retrieved from PubMed and Medline databases, in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement and following the Population Intervention Comparison Outcome (PICO) framework. Seven clinical studies were identified, which enlighten the association between thiamine supplementation, hyperglycemia, and cardiovascular disease (CVD). Although large-scale, multicenter studies with longer follow-up periods are needed, the association between thiamine and chronic metabolic dysfunction related to CV risk suggests its crucial role in preventing severe heart failure (HF).

Keywords: cardiovascular disease (CVD); endothelial dysfunction; hyperglycemia; hyperlactatemia; metabolic dysfunctions; thiamine supplementation.

Figure 1

Dietary intake is the main source of vitamin B1 as it is present in many foods: Whole grains, pulses, meat, fish, nuts, seeds, and vegetables.

Figure 2

Thiamine deficiency triggers a cascade: pyruvate accumulates in the cardiovascular system, stimulating lactic acid production, compromising CV function, and leading to higher ventricular filling pressures, oxygen consumption, and endothelial damage. At the metabolic level, thiamine deficiency impairs energy metabolism, ATP generation, and key metabolic enzymes. Lack of thiamine intensifies diabetes, its hyperglycemia, oxidative stress, and the creation of AGEs. Cardiovascular (CV); advanced glycation end-product (AGE); adenosine triphosphate (ATP).

Figure 3

Several conditions can cause thiamine deficiency: insufficient nutrition, reduced intestinal uptake, elevated metabolic rate, high kidney loss, alcohol dependence, lactation, hyperthyroidism, infections, and diabetes. Enlarged heart, edema, high venous pressure, and abnormal ECGs mark thiamine-deficient HF.

Figure 4

PRISMA Flow Chart.