| Sleep bruxism (SB) affects an estimated 8% of the adult population. SB is associated with chronic mental stress and increased sympathetic tone, risk indicators for the future development of hypertension. The purpose of this study was to assess the relationship between SB and the risk for future development of hypertension. Nineteen subjects (9 control (CON), 10 SB) had blood pressure (BP) and heart rate (HR) responses measured during baseline (BL), the cold pressor test (CPT), static handgrip to fatigue (SHG) with post-exercise circulatory arrest (PECA), and the Valsalva maneuver (VM). SB subjects underwent a 12 week occlusal splint intervention followed by a repeat of the experimental protocol. SB subjects participated in 24 hour ambulatory blood pressure monitoring within one week prior to both study visits. SBP was higher at BL in CON subjects (124+/-10 vs. 114+/-9 mmHg, CON vs. SB, respectively; P<0.05). No BL differences existed during pre- (PRE) vs. post-intervention (POST) in the SB subjects. CPT induced larger DeltaSBP (10+/-10 vs. 19+/-7 mmHg; P<0.05) and DeltaDBP (8+/-8 vs. 17+/-9 mmHg; P<0.05) in SB subjects compared to CON. POST had attenuated DeltaSBP (15+/-9 vs. 8+/-5 mmHg; P<0.03) and DeltaDBP (18+/-10 vs. 8+/-6 mmHg; P<0.05) during CPT. SB subjects experienced greater DeltaDBP (21+/-11 vs. 31+/-8; P<0.05) during SHG and were not improved during POST. No differences were found in VM responses between CON and SB subjects or during PRE vs. POST. In conclusion, SB individuals may be at increased risk for the future development of hypertension based on exaggerated BP responses to the CPT and SHG. The use of occlusal splint treatment for 12 weeks attenuates some of these responses, which may be due to lower BP surges during SB episodes and, consequently, lower sympathetic tone. It also indicates a possible reduced hypertension and cardiovascular risk in SB subjects who routinely use occlusal splint treatment. |
