REDUCED MYOCARDIAL FLOW RESERVE IN NON-INSULIN-DEPENDENT DIABETES-MELLITUS

Objectives. We analyzed myocardial flow reserve (MFR) in patients with non-insulin-dependent (type LI) diabetes mellitus (NIDDM) without sym ptoms and signs of ischemia. Background. Diminished MFR in diabetes ha s been suggested. However, it remains controversial whether MFR is rel ated to glycemic control, mode of therapy or gender in NIDDM. Methods. Myocardial blood flow (MBF) was measured at baseline and during dipyr idamole loading in 25 asymptomatic, normotensive, normocholesterolemic patients with NIDDM and 12 age-matched control subjects by means of p ositron emission tomography and nitrogen-13 ammonia, after which MFR w as calculated. Results. Baseline MBF in patients with NIDDM ([mean +/- SD] 74.0 +/- 24.0 ml/min per 100 g body weight) was comparable to tha t in control subjects (73.0 +/- 17.0 ml/min per 100 g). However, MBF d uring dipyridamole loading was significantly lower in patients with NI DDM (184 +/- 99.0 ml/min per 100 g, p < 0.01) than in control subjects (262 +/- 120 ml/min per 100 g), as was MFR (NIDDM: 2.77 +/- 0.85; con trol subjects: 3.8 +/- 1.0, p < 0.01). A significantly decreased MFR w as seen in men (2.35 +/- 0.84) compared with women with NIDDM (3.18 +/ - 0.79, p < 0.05); however, no significant differences were found in t erms of age, hemoglobin ale and baseline MBF. MFR was comparable betwe en the diet (2.78 +/- 0.80) and medication therapy groups (2.76 +/-: 0 .77) and was inversely correlated with average hemoglobin Ale for 5 ye ars (r = -0.55, p < 0.01) and fasting plasma glucose concentration (r = -0.57, p < 0.01) but not age or lipid fractions. Conclusions. Glycem ic control and gender, rather than mode of therapy, is related to MER in NIDDM. (C) 1997 by the American College of Cardiology.