INTERNATIONAL JOURNAL OF BEHAVIORAL MEDICINE, 6(2), 190-203 Copyright 9 i 999, Lawrence Erlbaum Associates, Inc. Hostility-Related Differences in the Associations Between Stress-Induced Physiological Reactivity and Lipid Concentrations in Young Healthy Women Edward C. Suarez and Tina L. Harralson We examined the relations of fasting lipid levels to stress-induced neuroendocrine and cardiovascular responses as a function of hostility in 36 healthy young women. Participants were women who scored above 17 (n = 23) or below 12 (n = 13) on the Cook-Medley Hostility (Ho) Inventory. Lipids were determined following an over- night fast. Individuals participated in a solvable anagram task, which evoked signifi- cant physiological responses in all participants. The Ho group by total serum choles- terol (TSC) and the Ho group by low-density lipoprotein (LDL) cholesterol interactions significantly predicted heart rate (HR) and norepinephrine (Ne) re- sponses. For high Ho women, elevations in TSC and LDL cholesterol were associated with smaller HR responses and larger Ne responses. In contrast, for low Ho women, elevations in TSC and LDL cholesterol were associated with larger HR responses and smaller Ne responses. Results also indicated a significant Ho group by TSC to high density lipoprotein (HDL) cholesterol ratio interaction for cortisol. For high Ho women, larger cortisol responses were associated with a greater TSC to HDL choles- terol ratio. For low Ho women, larger cortisol responses were associated with a smaller TSC to HDL cholesterol ratio. Lastly, higher TSC and LDL cholesterol levels were significantly associated with larger epinephrine responses. The findings suggest Edward C. Suarez, Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham, NC, USA; Tiua L. Harralson, Center for Clinical Epidemiology and Biostatistics, Uni- versity of Pennsylvania School of Medicine, Philadelphia, PA, USA. This work was supported by Grants HL- 46283 and HL-56105 from the National Heart, Lung, and Blood Institute. This study was conducted while Dr. Harralson was a post-doctoral fellow in the laboratory of Dr. Suarez. Correspondence concerning this article should be addressed to Edward C. Suarez, PO Box 3926, De- partment of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham, NC 27710.