IMPAIRED ARTERIAL BUT NOT VENOUS RESPONSIVENESS TO NITROGLYCERIN IN NON-INSULIN-DEPENDENT DIABETES-MELLITUS

In earlier studies, the response of the arterioles to nitroglycerin (N TG) was found to be impaired in noninsulin-dependent diabetes mellitus (NIDDM) patients. NTG has major therapeutic effects in reducing cardi ac after- and preload. Thus, the vasorelaxing efficacy of a therapeuti c dose of 0.4 mg of NTG sublingually (s.l.) was evaluated in the condu it femoral artery and large veins of normotensive, normoalbuminuric NI DDM patients. After NTG, the increase in the femoral artery diameter w as significantly lower in the NIDDM patients than in control subjects: 0.49 (0.29-0.79) vs. 0.75 (0.47-1.00) mm respectively (median, interq uartile ranges). NTG resulted in an increase of pulse wave transit tim e in the aorta in control subjects but not in the NIDDM patients: from 64 (60-73) to 70 (63-80) ms, P < 0.02; and from 62 (53-69) to 66 (51- 72)ms, P=NS, respectively. The reduction in the venous tone of the for earm to NTG was similar in both groups. These results suggest that the response to NTG is impaired in the arterial system but not in the ven ous system in well-regulated NIDDM patients without diabetic complicat ions.