EFFECTS OF CHRONIC SOCIAL SEPARATION ON CARDIOVASCULAR-DISEASE RISK-FACTORS IN FEMALE CYNOMOLGUS MONKEYS

A lack of social support is associated with increased risk of coronary heart disease morbidity and mortality in human beings. Similarly, chr onic social separation (single cage housing) potentiates atheroscleros is in female monkeys. Under the hypothesis that autonomic arousal and/ or ovarian impairment may mediate this effect las both are associated with increased atherosclerosis), heart rate and luteal phase plasma pr ogesterone concentrations were measured in 12 female cynomolgus monkey s that were first socially housed, then individually housed, and final ly returned to their original social groups. Afternoon heart rates inc reased during social separation compared to the social groupings (P < 0.001). Increased heart rates could not be explained by activity level s, which were lower during social separation than in social groupings (P < 0.001). Ovarian function (i.e. luteal-phase progesterone concentr ations) was not influenced by housing condition. Single caging reduced the extent of social signaling, even though animals were in visual an d auditory contact. Rates of affiliative behaviors increased and time spent alone decreased in post-reunion social groups compared to pre-se paration social groups (P's < 0.01). The results indicate that chronic social separation in this group-living species may exacerbate atheros clerosis via altered autonomic activity, as evidenced by higher heart rates during social separation. (C) 1998 Elsevier Science Ireland Ltd. All rights reserved.