Background: Emerging evidence indicates an association between sympathetic activation and metabolic syndrome. However, sympathetic activation in metabolic syndrome may be a cause, consequence, or just epiphenomenon. To elucidate this issue, the predictive power of resting heart rate for the development of abnormal glucose and lipid metabolisms after 20 years was evaluated in a general population.
Methods: A total of 637 participants (>20 years old) underwent a health examination in 1979 including measurements of blood chemistries. Resting heart rate (bpm) was measured by an electrocardiogram. In 1999, all of the study participants again underwent a health examination, including electrocardiogram and blood chemistries. Because four of them had atrial fibrillation, and 19 subjects were taking antihypertensive medication in 1979, they were excluded from analysis. Therefore, a complete dataset of 614 subjects was available.
Results: As was reported in our previous article, in 1999 we found a linear and significant (P < 0.05) cross-sectional relationship between resting heart rate and a cluster of cardiometabolic risk factors (blood pressure (BP), free fatty acid (FFA), plasma glucose, and homeostasis model assessment (HOMA) index). Baseline higher heart rate (heart rate >or=80 bpm in 1979) predicted the development of obesity, diabetes mellitus (DM), and insulin resistance in 1999 after adjustments for age, sex, and other confounders.
Conclusion: This is one of the first prospective reports demonstrating that higher heart rate may predispose to the development of obesity and DM, suggesting that the sympathetic nerve system may play a role in the development of obesity and DM.