Objective: To examine the relationship between mood and blood glucose in a 21-day daily diary study.
Design: During a home visit, information was gathered from 206 persons with Type 2 diabetes regarding demographics, disease characteristics and treatment, and depressive symptoms. They had blood drawn at a laboratory, yielding HbA1C. The participants were then telephoned each evening for 21 days and were asked about their positive and negative mood during the past 24 hours. They also tested their blood glucose upon rising in the morning.
Main outcome measures: The main outcomes measures were positive and negative affect and fasting glucose.
Results: Multilevel analyses revealed a relationship between negative affect on one day and morning glucose on the next day. There was no such relationship between positive affect and glucose, nor was there a comparable effect of glucose on one day and either positive or negative affect on the next day.
Conclusion: The observed relationship between mood and blood glucose appears to be because of negative affect, not positive, with no evidence of a lagged effect of glucose on mood.