The relationship of subtle differences in fasting blood glucose with subtle differences in the electrocardiogram: a study of the PR interval.

There are now well-established relationships between the trinity of classical diabetes mellitus, defined cardiovascular syndromes, diverse overt electrocardiographic patterns. What has not been considered is the possible relationship of the subtle forms of prediabetes (meaning nonspecific patterns of carbohydrate metabolism) and subtle expressions of electrocardiographic aberration. The evidence presented herein suggests a real and significant parallelism between the PR interval and small differences in fasting blood glucose not previously reported. Additionally, the data suggest that while it may be normal (average) for the PR interval to increase with advancing age, it is not normal (physiologic) for the PR interval to enlarge in the autumnal years.