The CLOCK 3111T/C SNP is associated with morning gastric motility in healthy young women.

Circadian locomotor output cycles kaput (CLOCK) molecule plays major roles in circadian rhythmicity and regulates daily physiological processes including digestive activity. Therefore, we hypothesized that the CLOCK 3111T/C single nucleotide polymorphism (SNP) might have adverse effects on the regulation of gastric motility. Based on the hypothesis, we investigated whether this SNP was associated with morning gastric motility. Ninety-five female university students (19.6±0.2 years) completed life-style questionnaires. Gastric motility, evaluated by electrogastrography (EGG), blood pressure (BP), and heart rate variability (HRV) were measured at 8:30 a.m. after an overnight fast. To determine the gastric motility, the spectral powers and dominant frequency (DF, a peak of the spectrum) of the EGG were calculated. No significant differences were found in breakfast frequency, energy intake, or HRV between CLOCK 3111T/C minor C allele (T/C or C/C) and T/T subjects. However, C allele carriers showed significantly lower DF than T/T subjects, suggesting slower gastric motility. Moreover, C allele carriers had a lower heart rate (HR) and tended to have lower diastolic BP compared with T/T subjects. These results support our hypothesis that this SNP is likely correlated with morning gastric motility. Such attenuated gastric and cardiovascular function that characterized CLOCK 3111C allele carriers could be affecting biological behavior in the morning.

The effects of carbonated water upon gastric and cardiac activities and fullness in healthy young women.

Although previous reports suggested that carbonated water drinking was effective against gastrointestinal symptoms, there is little information about the effects of carbonated water on gastric and appetite sensation. We therefore investigated the effect of carbonated water on short-term fullness with respect to gastric and cardiac responses in 19 healthy young women. Each subject was tested on three separate days at approximately 9 a.m. after an overnight fast. Gastric motility, evaluated by electrogastrography (EGG) and heart rate (HR), was measured for 20 min in the fasting state and 40 min after ingestion of water. Preloads consisted of an equivalent amount (250 mL) of water (W) or carbonated water (CW) and no drinking (blank). Fullness scores were measured using visual analog scales. To determine gastric motility, we assessed the component of bradygastria (1-2 cycles/min [cpm]), normogastria (2-4 cpm), tachygastria (4-9 cpm), and dominant frequency of the EGG power spectrum. After ingestion of CW, significant increases in fullness scores were observed compared with W. All postprandial EGG powers were significantly greater than preprandial, but no group difference was found. However, a dominant frequency tended to shift toward a lower band after ingestion of W. A significantly higher HR was found following consumption of CW as opposed to W. Multiple regression analysis revealed that increased HR was a significant variable contributing to the variances in fullness after ingestion of CW at 40 min. Our data suggest that CW may induce a short-term, but significant, satiating effect through enhanced postprandial gastric and cardiac activities due possibly to the increased sympathetic activity and/or withdrawal of parasympathetic activity.