Coronary microangiopathy in type 2 diabetic patients: Relation to glycemiccontrol, sex, and microvascular angina rather than to coronary artery disease

Coronary microangiopathy is a major complication in diabetics. However, the presence of independent factors in association with coronary microangiopat hy in patients with non-insulin-dependent diabetes mellitus (NIDDM) or the difference in coronary microangiopathy between diabetics with coronary arte ry disease (GAD) and those with microvascular angina is unclear. Methods: N ineteen patients with NIDDM and microvascular angina, 18 patients with NIDD M and CAD, and 17 age-matched control subjects were studied. Myocardial seg ments that were perfused by angiographically normal coronary arteries were studied. The baseline myocardial blood flow (MBF) and the MBF during dipyri damole administration were measured using PET and N-13-ammonia, after which the myocardial flow reserve (MFR) was calculated to assess coronary microa ngiopathy. Results: The baseline MBF was comparable among NIDDM patients wi th microvascular angina, NIDDM patients with GAD, and control subjects. How ever, the MBF during dipyridamole administration was significantly lower in NIDDM patients with microvascular angina (126 +/- 42.7 mL/min/100 g) than that in either NIDDM patients with CAD (210 +/- 70.1 mL/min/100 g; P < 0.01 ) or control subjects (293 +/- 159 mL/min/100 g; P < 0.01), as was the MFR (NIDDM with microvascular angina, 1.90 +/- 0.73; NIDDM with CAD, 2.59 +/- 0 .81 [P < 0.01]; control subjects, 3.69 +/- 1.09 [P < 0.01]). Multivariate s tepwise regression analysis showed that, among the factors considered, glyc emic control was independently related to the MFR (r = 0.838; P< 0.05). Con clusion: Glycemic control appears to be essential for coronary microangiopa thy in NIDDM.