Psychosocial factors impair vascular responses of coronary arteries.

BACKGROUND: Four sets of monkeys were used to examine the effect of chronic psychosocial disruption and diet on dilator responses of coronary arteries. METHODS AND RESULTS: One set consisted of monkeys consuming monkey chow and living in a stable social setting (nonatherosclerotic controls, n = 6). Three sets consumed an atherogenic diet for 14 months followed by one of three treatments for the next 16 months: 1) a high-cholesterol diet and housed in unstable social groups (n = 9); 2) a low-cholesterol diet and housed in unstable (n = 8); or 3) stable groups (n = 10). Quantitative coronary angiography revealed that intracoronary infusion of acetylcholine resulted in a change of diameter (versus infusion of 5% dextrose in water) of +4 +/- 1% in control monkeys and -11 +/- 4% in unstable monkeys consuming a high-cholesterol diet (p less than 0.05). In monkeys consuming the cholesterol-lowering diet, the change in artery diameter was +2 +/- 4% in stable and -10 +/- 4% in unstable social conditions (p less than 0.05) despite a similar plaque size (0.4 +/- 0.2 and 0.5 +/- 0.1 mm2) and total plasma cholesterol concentrations (179 +/- 9 and 172 +/- 6 mg/dl), respectively. The arterial response to nitroglycerin was similar among all groups of monkeys. CONCLUSIONS: We conclude that chronic social disruption is associated with relative arterial constriction in response to acetylcholine in atherosclerotic monkeys consuming a cholesterol-lowering diet.