DOMINANT SOCIAL-STATUS AND CONTRACEPTIVE HORMONE-TREATMENT INHIBIT ATHEROGENESIS IN PREMENOPAUSAL MONKEYS

The stress of social subordination is associated with exacerbation of coronary artery atherosclerosis in premenopausal cynomolgus monkeys, p ossibly as a result of the ovarian dysfunction that reliably accompani es subordinate social status. The primary objective of the current stu dy was to determine whether treatment with an oral contraceptive (OC) provides relative protection from development of atherosclerotic plaqu es, especially among animals made vulnerable to atherosclerosis by soc ial subordination, In the present study, 193 adult female monkeys (Mac aca fascicularis) were placed in social groups of 5 or 6 animals each. Half of the animals were then fed an atherogenic diet to which had be en added a triphasic OC, while the remainder received only the atherog enic diet. At the end of 26 months, atherosclerosis was measured in an iliac artery biopsy taken from each monkey. The results demonstrated that among untreated animals subordinate individuals developed signifi cantly more atherosclerosis than did their dominant counterparts (P<.0 1); however, OC treatment inhibited atherosclerosis in subordinate ani mals (P<.05) and eliminated the difference between dominant and subord inate animals that was observed in the untreated condition. Subordinat e social status and OC treatment were both associated with reduced pla sma concentrations of HDL cholesterol (P<.01 for both), and subordinat e monkeys also had elevations in LDL cholesterol plus VLDL cholesterol (P<.01). Nonetheless, the interaction between social status and OC tr eatment remained significant even after covariance adjustment for vari ation in plasma lipids. Taken together, these results suggest that soc ial subordination worsens, whereas OC treatment inhibits, atherosclero sis, and that these effects are independent of concomitant variability in plasma lipids.