Does the biorhythm of morningness or eveningness predict the arterial blood pressure level?

With the aid of a special questionnaire 16 healthy persons were divided to morning or evening types of personalities. Their arterial blood pressure was registered ambulatorily for 24 hours in order to elucidate the difference of blood pressure reactions between the groups. The average maximum blood pressure occurred 3.5 hours later in evening types than in morning types. Individually there were very small differences and it seems that the blood pressure level is more affected by physical activity than by morningness or eveningness.