The Relationship between the Plasma Concentration of Electrolytes and Intensity of Sleep Bruxism and Blood Pressure Variability among Sleep Bruxers

Plasma sodium plays a major role in regulating blood pressure (BP). An augmented variability of BP is considered a risk factor for the development of arterial hypertension, which is prevalent among patients with suspected sleep bruxism (SB). The aims of this study were to assess the plasma concentration of electrolytes and their effect on the intensity of SB and BP variability among sleep bruxers. A total of 51 patients were enrolled in this prospective, observational study. A single full-night polysomnographic examination was conducted in the Wroclaw Medical University Sleep Laboratory, Poland, and based on the guidelines of the American Academy of Sleep Medicine, the results were analyzed. The monitoring of ambulatory BP was performed the next day, and the plasma levels of sodium, potassium, magnesium, and calcium were measured. The mean age of the studied group was 33.9 ± 11.2 years, and the mean bruxism episode index (BEI) was 4.94 ± 3.53. The study revealed statistically significant differences in the plasma concentrations of sodium in the SB group. A decreased sodium concentration was observed in the group of mild bruxers (2 ≤ BEI < 4) (139.7 ± 1.4 vs. 142.8 ± 3.2, p = 0.002) and severe bruxers (BEI ≥ 4) (140.5 ± 2.0 vs. 142.8 ± 3.2, p = 0.016) compared to nonbruxers (BEI < 2). A statistically significant positive linear correlation was found between plasma sodium concentration and daytime systolic BP variability (r = 0.32, p < 0.05) as well as between plasma sodium concentration and nighttime diastolic BP variability (r = 0.31, p < 0.05). The preliminary results suggest the probable relationship between the lower plasma concentration of sodium and increased intensity of SB and BP variability among suspected sleep bruxers.