Influence of Caffeine on Frequency of Hypoglycemia Detected by Continuous Interstitial Glucose Monitoring System in Patients With Long-Standing Type 1 Diabetes

Abstract

OBJECTIVE—The aim of this study was to investigate the effect of caffeine (in doses equivalent to normal daily ingestion) on rates and severity of hypoglycemia in patients with long-standing type 1 diabetes to determine the relationship between caffeine, autonomic function, and hypoglycemia.

RESEARCH DESIGN AND METHODS—Using a double-blinded randomized study, we investigated the effect of caffeine versus placebo in 19 patients with long-standing type 1 diabetes using continuous glucose sensing technology and simultaneous assessment of autonomic function using Holter monitoring.

RESULTS—Caffeine reduced the duration of nocturnal hypoglycemia with a mean duration of 49 minutes (range 0–235) versus 132 (0–468) minutes (P = 0.035). The reduction in duration of nighttime hypoglycemia was due to a decline in the number of episodes of moderate hypoglycemia at the expense of mild hypoglycemic episodes (P = 0.04). There was no overall correlation between reduced heart rate variability (a marker of autonomic dysfunction) and hypoglycemic events (r_s = 0.12, P = 0.62).

CONCLUSIONS—Our results suggest that caffeine is associated with a significant reduction in nocturnal hypoglycemia. The reduction in nocturnal hypoglycemia was not linked to the concomitant rise in parasympathetic activity associated with caffeine.