Acute hyperglycemia induced by oral glucose loading suppresses coronary microcirculation on transthoracic Doppler echocardiography in healthy young adults.
OBJECTIVE
We sought to evaluate the effect of acute hyperglycemia on coronary microcirculation by noninvasive measurement of coronary flow velocity reserve (CFVR) using transthoracic Doppler echocardiography (TTDE).


METHODS
Measurements of CFVR using TTDE and levels of plasma glucose and serum insulin and lipids were determined before and 1 hour after loading with oral glucose (75-g glucose) in 10 young healthy males (mean age, 30 +/- 2 years) or an artificial sweetener in five of the 10 subjects without coronary risk factors.


RESULTS
In all subjects, the levels of plasma glucose and serum insulin significantly increased after glucose loading compared with baseline (5.1 +/- 0.6 vs 7.6 +/- 1.2 mM/l, 6 +/- 3 vs 49 +/- 13 microU/ml, respectively; P < 0.0001). CFVR was significantly decreased 1 hour after acute oral glucose loading (4.4 +/- 0.7-3.8 +/- 0.7, respectively; P < 0.01). There was no significant change in CFVR after loading with an artificial sweetener (4.4 +/- 0.6-4.4 +/- 0.5 cm/sec).


CONCLUSIONS
TTDE revealed that acute hyperglycemia induced by oral glucose loading suppresses CFVR in healthy young male subjects. This result suggests that acute hyperglycemia may have adverse effects on coronary microcirculation.
Fujimoto
Kohei
K
Department of Internal Medicine and Cardiology, Osaka City University Medical School, Osaka, Japan.
Hozumi
Takeshi
T
Watanabe
Hiroyuki
H
Tokai
Kotaro
K
Shimada
Kenei
K
Yoshiyama
Minoru
M
Homma
Shunichi
S
Yoshikawa
Junichi
J
D000208:Acute Disease; D000284:Administration, Oral; D000328:Adult; D015415:Biomarkers / Q000097:blood; D001783:Blood Flow Velocity / Q000187:drug effects; D001786:Blood Glucose / Q000187:drug effects / Q000378:metabolism; D001794:Blood Pressure / Q000187:drug effects; D001916:Brachial Artery / Q000187:drug effects / Q000503:physiopathology; D008076:Cholesterol, HDL / Q000097:blood / Q000187:drug effects; D003326:Coronary Circulation / Q000187:drug effects*; D015150:Echocardiography, Doppler; D005947:Glucose / Q000009:adverse effects*; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D006943:Hyperglycemia / Q000139:chemically induced* / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000503:physiopathology*; D007328:Insulin / Q000097:blood; D008297:Male; D008833:Microcirculation / Q000187:drug effects; D015588:Observer Variation; D012107:Research Design; D013549:Sweetening Agents / Q000009:adverse effects*; D013997:Time Factors; D014280:Triglycerides / Q000097:blood; D014664:Vasodilation / Q000187:drug effects
D015415:Biomarkers; D001786:Blood Glucose; D008076:Cholesterol, HDL; D007328:Insulin; D013549:Sweetening Agents; D014280:Triglycerides; D005947:Glucose