Noriyuki Fujii

Insulin resistance functionally limits endothelium-dependent coronary vasodilation in nondiabetic patients

Insulin resistance (IR) is now considered to be a risk factor for coronary arterial atherosclerosis and is likely to be involved in a limited endothelium-dependent vasodilatory function in peripheral circulation. We investigated whether IR impairs endothelial vasodilator function in the noninfarcted coronary artery. In 14 nondiabetic patients (10 males, 66 ± 6 years) who were selected from 214 patients underwent IR evaluation by glucose clamp, a Doppler flow wire was used to measure coronary flow changes (percent volume flow index, %VFI) during intracoronary administration of papaverin (10 mg) and stepwise administration of acetylcholine (Ach; 1, 3, 10 μg/ml per minute) into the non-infarcted left circumflex coronary artery. Insulin resistance was comparatively evaluated by an euglycemic hyperinsulinemic glucose clamp (M value, mg/m2 per minute) or by a 75g-oral glucose tolerance test (120-min immunoreactive insulin; 120′ IRI, pmol/l). Eight patients (57%) were defined as having IR on the basis of results obtained by both the glucose clamp method (M values <167 mg/m2 per minute) and 120′ IRI (>384 pmol/l). There was no difference between papaverin-induced %VFI increases in IR and non-IR subjects (328% ± 43% vs. 361% ± 87%). However, IR subjects showed significantly lower Ach-induced %VFI increases in a dose-dependent manner (P < 0.05), especially when low (1 μg/ml per minute) and moderate (3 μg/ml per minute) doses of Ach were used (165% ± 18% or 248% ± 29% in non-IR subjects vs. 130% ± 20% or 183% ± 41% in IR subjects, P < 0.001, respectively). Moreover, %VFI increase at a low dose of Ach infusion significantly correlated with M values or 120′ IRI ([%VFI Ach 1 μg] = 85.9 + 0.35 [M values], r = 0.58, P = 0.038; [%VFI Ach 1 μg] = 176.8 − 0.47·[120′ IRI], r = −0.57, P = 0.035). Insulin resistance limits endothelium-dependent coronary vasodilation in association with the severity of IR in non-diabetic patients.

Clinical characteristics and outcomes in super‐elderly patients (>85 years) with heart failure: single center observational study in Japan

The number of elderly patients with heart failure is increasing in Japan owing to the increase in the aging population. In the field of emergency medicine, the treatment and management of elderly patients with heart failure are key issues. We aimed to clarify the clinical characteristics and outcomes of these patients.