Abstract: Objective To determine the association between serum potassium level and the severity of coronary artery atherosclerosis. Methods A total of 246 patients underwent coronary artery angiography were included into this study, and were divided into four groups according to the involved main coronary artery: control group (0 diseased vessel, n=81), one diseased vessel group (n=43), double diseased vessel group (n=46) and three diseased vessel group (n=76). Patients were also divided into low potassium group (K +<4.0 mmol/L, n=99) and high potassium group (K +≥4.0 mmol/L, n=147) according to the levels of serum potassium. The severity of coronary stenosis was quantitated by Gensini score system. The clinical data were compared between groups. The relationship between Gensini score system and clinical information was analyzed. The multiple regression method was used to analyse the risk factors of coronary heart disease (CHD). Results (1) There were higher percentages of elders, male, smoking, diabetes mellitus and hypertension patients in three diseased vessel group than those of control group. The serum potassium level was significantly lower in three diseased vessel group (3.97 mmol/L±0.37 mmol/L) than that of control group (4.11 mmol/L±0.33 mmol/L) and one diseased vessel group (4.13 mmol/L±0.41 mmol/L). There were higher percentages of elders, male and hypertension patients in double diseased vessel group than those of control group. The percentages of male and hypertension patients were higher in one diseased vessel group than those of control group. The Gensini scores were three diseased vessel group > double diseased vessel group > one diseased vessel group > control group (P < 0.05). (2) There was a significantly higher Gensini score in low potassium group [36(8, 94)] than that of high potassium group [16（0， 56)]. (3) There was significant negative correlation between serum potassium level and Gensini score (r=-0.206, P=0.001). (4) It was found that age, male, the low level of serum potassium, diabetes mellitus and hypertension were independent risk factors of CHD. Conclusion The serum potassium level is negatively correlated with the severity of CHD. The low level of serum potassium is an independent risk factor of CHD.

Key words: serum potassium, coronary atherosclerotic lesion, risk factors, atherosclerosis, Gensini&rsquo, s score