Effects of bazedoxifene, conjugated equine estrogens, and a tissue-selective estrogen complex containing both bazedoxifene and conjugated equine estrogens on cerebral artery atherosclerosis in postmenopausal monkeys.

OBJECTIVE: This study aims to evaluate the effects of a new selective estrogen receptor modulator (bazedoxifene acetate [BZA]) and a tissue-specific estrogen complex (BZA combined with conjugated equine estrogens [CEE]) on the extent and severity of cerebral artery atherosclerosis. METHODS: Ninety-eight surgically postmenopausal monkeys (Macaca fascicularis) were fed a moderately atherogenic diet and randomized to receive no treatment or women's equivalent doses of BZA (20 mg/d), CEE (0.45 mg/d), or BZA + CEE. After an experimental period of 20 months (approximately equivalent to 5 years of participant experience), the extent and severity of atherosclerosis in the common carotid artery, carotid bifurcation, internal carotid artery, and basilar artery were determined. Lesion severity was determined using the American Heart Association grading system (grades 0-V). RESULTS: BZA had no consistent adverse effects on the extent and severity of atherosclerosis in the cerebral arteries and did not attenuate the beneficial effects of CEE on the severity of common carotid artery atherosclerosis. Although CEE had only modest beneficial effects on the extent of carotid bifurcation atherosclerosis, the severity of lesions and the number of affected cases in the common carotid artery were reduced with CEE treatment. As reported previously, plasma lipid profiles did not differ among the treatment groups. CONCLUSIONS: In this long-term (equivalent to 5 human patient-years) nonhuman primate trial, BZA shows no consistent adverse effect on cerebral artery atherosclerosis and does not attenuate the modest beneficial effect of CEE on the common carotid artery. Furthermore, CEE inhibits the development of complicated plaques in the common carotid artery.

Effects of bazedoxifene alone and with conjugated equine estrogens on coronary and peripheral artery atherosclerosis in postmenopausal monkeys.

OBJECTIVE: The objectives of this study were to evaluate the effects of bazedoxifene acetate (BZA), a new selective estrogen receptor modulator, on coronary and peripheral artery atheroscleroses and to determine if it would antagonize the atheroprotective effects of conjugated equine estrogens (CEE) on a monkey model. METHODS: Ninety-eight surgically postmenopausal monkeys (Macaca fascicularis) were fed a moderately atherogenic diet and randomized to receive no treatment or women's equivalent doses of BZA (20 mg/d), CEE (0.45 mg/d), or BZA + CEE. The experimental period lasted for 20 months (equivalent to approximately 5 y in humans) during which interim measures of cardiovascular risk factors were made. At the end of the experimental period, the extent and severity of coronary and iliac artery atheroscleroses were quantified. RESULTS: Body weight, adiposity, fasting glucose concentrations, and plasma lipid profiles were not different among treatment conditions. BZA had no adverse effects on the extent or severity of coronary or common iliac artery atherosclerosis when compared with no treatment. CEE, administered soon after inducing menopause, had robust atheroprotective effects on both the extent and the severity of iliac and coronary artery atheroscleroses. The addition of BZA to CEE treatment antagonized the atheroprotective effects of CEE. CONCLUSIONS: In this nonhuman primate trial, treatment with BZA alone, CEE alone, and combined BZA and CEE does not have significant effects on plasma lipid profiles. CEE markedly inhibits the progression and complications of both coronary and iliac artery atheroscleroses. BZA has no adverse effects on atherosclerosis but attenuates the atheroprotective effects of CEE.

Depressive behavior and coronary artery atherogenesis in adult female cynomolgus monkeys.

OBJECTIVE: To examine depressive behavior and early coronary artery atherogenesis in 36 socially housed female cynomolgus monkeys, an established model of atherogenesis and depression. Coronary heart disease (CHD) is caused by coronary artery atherosclerosis (CAA) and its sequelae which develop over a period of decades. Thus, in prospective studies of depression and CHD, CAA was likely present at baseline in most subjects who experienced cardiac events. Little is known about the relationship between depression and CAA. METHODS: The monkeys were free of atherosclerosis before being fed a diet containing moderate amounts of fat and cholesterol for 52 months. Depressed behavior and activity levels recorded in weekly 15-minute focal samples, telemetered 24-hour heart rate, plasma total (TPC) and high-density lipoprotein cholesterol (HDLC), luteal phase serum progesterone concentrations, basal cortisol, cortisol response to corticotrophin-releasing hormone (CRH), and CAA extent were assessed. RESULTS: Time spent in depressed behavior over 4 years was significantly associated with early CAA (r = .73, p < .001), as were activity level, 24-hour heart rate, TPC, HDLC, cortisol response to CRH, and mean peak progesterone (all p < or = 0.05). Depressed females had four times the CAA compared with nondepressed females. CONCLUSIONS: Depression in primates is associated with perturbations in multiple CHD risk factors and accelerated early atherogenesis. These data are consistent with the hypotheses that depression and CAA both stem from a common mechanism and that depression may cause CAA.