Influence of genetic polymorphisms and habitual caffeine intake on the changes in blood pressure, pulse rate, and calculation speed after caffeine intake: A prospective, double blind, randomized trial in healthy volunteers.

The aim of this study was to investigate the contribution of gene polymorphisms, in combination with habitual caffeine consumption, to the effect of caffeine intake on hemodynamic and psychoactive parameters. A double-blind, prospective study was conducted with 201 healthy volunteers randomly allocated 2:1 to the caffeinated group (150 mL decaffeinated coffee with additional 200 mg caffeine) or decaffeinated group (150 mL decaffeinated coffee). We measured the changes in blood pressure (BP) and calculation speed upon coffee intake, stratifying with gene polymorphisms, e.g., those in adenosine A2A receptor (ADORA2A) and cytochrome P450 (CYP) 1A2, and daily caffeine consumption (≤90 mg/day and >90 mg/day). Overall, caffeine intake independently increased BP and calculation speed (p-values < 0.05), irrespective of the polymorphisms. In stratified analysis, a statistical significance within the caffeinated group was observed for the change in systolic BP in the stratum of CYP1A2 polymorphism with daily caffeine consumption ≤90 mg/day: change in systolic BP in the CYP1A2 rs762551 CC group (mean ± SD = 11.8 ± 5.9) was higher than that in the AA/CA group (4.1 ± 5.5). Gene polymorphisms may limitedly modify the effect of caffeine intake on hemodynamic parameters in combination with habitual caffeine consumption.

Optimal Thermal Control with Sufficient Nutrition May Reduce the Incidence of Neonatal Jaundice by Preventing Body-Weight Loss Among Non-Low Birth Weight Infants Not Admitted to Neonatal Intensive Care Unit.

BACKGROUND: Neonatal jaundice is strongly attributable to excess body-weight loss as a result of insufficient calorific intake. OBJECTIVES: To examine the incidence of neonatal jaundice (defined by use of phototherapy) and body-weight loss, as well as their association, among neonates under optimal thermal control with sufficient nutrition, a local protocol for temperature and nutritional regulation. METHODS: We retrospectively identified a cohort of 10,544 neonates (birth weight ≥2,500 g) placed in thermo-controlled incubators for 2 h immediately after birth. Neonates were fed with 5% glucose solution 1 h after birth and breastfed every 3 h (with supplementary formula milk if applicable) according to basal maintenance expenditure. Total serum bilirubin levels at day 4 (peak level) were assessed. Phototherapy was performed on the basis of total serum bilirubin level ≥18 mg/dL. Risk ratio (RR) and 95% CI for the use of phototherapy against maximum body-weight loss were estimated using Poisson regression with robust variance. RESULTS: Incidence of phototherapy use was low (0.3%) and the mean total serum bilirubin level was 8.5 mg/dL (SD 2.7 mg/dL), with a low mean maximum body-weight loss (1.9%) and low incidence of excess body-weight loss ≥7% (0.4%). Maximum body-weight loss was associated with risk of neonatal jaundice (RR 1.27; 95% CI 1.04-1.54), and became significant at approximately 4% of maximum body-weight loss. CONCLUSION: Optimal thermal control and sufficient nutrition may greatly reduce the incidence of neonatal jaundice by preventing neonatal body-weight loss.