ASSOCIATION BETWEEN ANGINA PECTORIS AND HYPERINSULINISM IN POSTMENOPAUSAL WOMEN

Cardiac X Syndrome is the occurrence of angina pectoris in spite of a normal coronary angiogram, probably due to a disorder of the cardiac sensory nervous system (pain perception). The insulin resistance (metabolic X) syndrome is an important determinant of coronary artery disease. There is a dearth of research on the association between insulin resistance and cardiac X syndrome. We compared the hormonal status of three groups of postmenopausal women: those with cardiac X syndrome, those with coronary artery disease, and healthy controls. 149 postmenopausal women (age range 48-58 years), matched for duration of menopause, were recruited for this study. Gonadotrophin and fasting insulin levels as well as blood pressure and body mass index were measured in all three groups. LH, FSH, oestradiol and progesterone levels were similar in all three groups. Women in the first two groups (that is, those with angina pectoris regardless of the result of coronary angiography) had a significantly higher BMI than controls. Fasting insulin levels were significantly higher in the first two groups compared with controls (p<0.01). There was no difference in fasting insulin level between the normal and abnormal angiography groups. There was no significant correlation between fasting insulin and any of the other variables, even though the association between fasting insulin and BMI in the abnormal angiography-confirmed CAD group very nearly approached statistical significance (p=0.059). Women with angina pectoris, regardless of the outcome of coronary angiography, have hyperinsulinism and a higher BMI than controls. It seems that hyperinsulinism is the fundamental mechanism by which both the cardiac X and metabolic X syndromes occur. Further research is needed to elucidate this matter.