Neonatal blood pressure and salt taste responsiveness

To test the association between neonatal blood pressure (BP) and salt taste response, 283 healthy hospitalized neonates were administered small drops (0.06 mL) of water and 0.1 molar (mol/L) and 0.3 mol/L NaCl solutions by means of cannulas through a nipple with a pressure transducer to record sucking responses. Neonatal and 1-month BPs were recorded by ultrasound. Mean number of sucks per burst was scored as "aversive" if the 0.3 mol/L salt minus water difference score was < or =-10 mean sucks per burst, "preferential" if this difference was >0, and "neutral" otherwise. Babies with "preferential" responses had higher diastolic BPs than those with neutral (1.9 mm Hg) or aversive responses (3.1 mm Hg) (P trend=0.05). After adjustment for age, gender, birth weight, and activity for babies with at least one grandparent receiving antihypertensive medication, mean adjusted systolic pressure was 6.7 mm Hg higher (P=0.003) (P trend=0.003) and mean adjusted diastolic pressure was 5.0 mm Hg higher (P=0.010) (P trend=0.011) in neonates with preferential versus aversive salt taste responses. There was no relation of BP to sucking responses to sweet (sucrose) stimuli. Neonates can distinguish between dilute salt solutions and water. This response is related to BP and might be a potential risk factor for high BP later in life.