Stress and metabolic control in diabetes mellitus: methodological issues and an illustrative analysis.

RATIONALE: The purpose of this article was twofold: a) to review studies of stress and glycemic control in diabetes, and b) to present a data analysis that illustrates the complexities of investigating stress in relation to blood glucose. The literature review emphasized human studies and the strengths and weaknesses of alternative designs. Special consideration was given to longitudinal investigations, and an analysis of data from the Diabetes Control and Complications Trial (DCCT) was presented to exemplify this approach. Nine individuals with Type 1 diabetes who participated in this project at the University of Iowa were studied over a period of 2 years. Stress was multiply measured (Life Experiences Survey, Hassles Scale, Perceived Stress Scale) as was blood glucose control (daily reflectance meter readings; monthly HbA1c). Within-subject time-series analyses and a combined longitudinal/cross-sectional model were used to analyze data. Two of the nine subjects manifested significant correlations between stress and HbA1c, and six subjects exhibited significant associations between stress and daily level or variability of glucose readings. The latter correlations varied in sign and appeared to cluster around specific individuals rather than a particular measure of stress or blood glucose.
CONCLUSION: While the subjects may not represent the full spectrum of individuals with Type 1 diabetes, results were consistent with earlier longitudinal research in suggesting that the strength and direction of the relationship between stress and blood glucose control varies considerably between individuals.