Study of Morning Coffee Intake in Healthy Subjects Using Pulse Rate Variability

Abstract

It is well known that coffee has significant affect in the functioning of autonomic nervous system (ANS). Non-invasive study of ANS by heart rate variability was well documented. We aimed to study the effect of one cup of early morning coffee ingestion in healthy adults. We included total 35 healthy college going students with a mean age of 21.628 years. 5 minutes continuous photoplethysmogram(PPG) signal was recorded in three steps: one before coffee intake and after that two readings at an interval of 30 minutes after coffee intake. 12 features defining heart rate variability were obtained using Kubios software and significant difference were computed using statistical analysis. Only high frequency power indicating parasympathetic division of ANS showed significant decrease after half an hour of coffee intake which was again neutralised after one hour.