ORIGINAL ARTICLE Chronic distress and acute vascular stress responses associated with ambulatory blood pressure in low-testosterone African men: the SABPA Study NT Malan 1 , T Stalder 2 , MP Schlaich 3 , GW Lambert 3 , M Hamer 1,4 , AE Schutte 1 , HW Huisman 1 , R Schutte 1 , W Smith 1 , CMC Mels 1 , JM van Rooyen 1 and L Malan 1 It is known that low testosterone (T) and high cortisol levels are associated with hypertension as well as with chronic stress, linking stress with elevated blood pressure (BP). However, the association between acute stress-, chronic stress responses and BP is not clear in Africans. Therefore, we examined the association between cortisol, psychological distress and BP responses in low- and high-T male subgroups. Beat-to-beat and ambulatory blood pressure (ABPM) and electrocardiogram measures were obtained. Serum samples were collected and analyzed for sex hormones and cortisol. Chronic psychological distress was verified with the General Health Questionnaire and acute stress with the cold pressor test. More chronic psychological distress was observed in both low- and high-T Africans compared with the Caucasians. The low-T Africans tended to have more ischemic events (P ¼ 0.06) and ABPM values (Pp0.01) than any of the other groups. Both chronic distress (cortisol) and acute stress (total peripheral resistance cold pressor responses) were associated with ABPM in the low-T African group. Acute and chronic stress may contribute to increased BP in low-T African men. Their cortisol and vascular responses supported a tendency for ischemia, increasing their risk for coronary artery disease. Journal of Human Hypertension (2014) 28, 393–398; doi:10.1038/jhh.2013.124; published online 28 November 2013 Keywords: low testosterone; stress; cortisol; ischemic events; blood pressure; Africans INTRODUCTION It is well established that blood pressure (BP) will increase, whereas the level of testosterone (T) will decline with age. 1 In addition, low T is associated with endothelial dysfunction independent of other risk factors indicating a protective role of T on the endothelium. 2,3 We have previously reported that low T may both result from and contribute to increased sympathetic activity 4 which, in turn, may be related to an increased secretion of cortisol. An increase in cortisol is associated with elevated BP, while elevated cortisol-to-T ratio is associated with ischemic heart disease, 5 whereas a low-T level is associated with ST segment depression. 6 An increase in the cortisol-to-T ratio may, therefore, be the result of an age-related decrease in the T levels and/or sympathetic activity or as result of an increase in cortisol presumably due to augmented sympathetic outflow to the adrenal. The situation, however, is complicated by the fact that chronic stress may lead to a downregulation of cortisol. 7 Interpretation of the effects of a change in cortisol-to-T ratio should, therefore, be done with care. There is also some controversy whether cortisol is correlated with hypertension. Whitworth et al. 8 reported that cortisol administration in humans reproducibly increased BP. Esler et al. 9 supported these findings by revealing elevated cortisol in essential hypertensive patients. However, there are authors who failed to find such a relationship. 8 Mansour et al. 10 noted possible coronary vasospasm during panic attacks. If this type of contraction also occurs in the systemic circulation, it may provide another possible mechanism by which increased cortisol levels may influence BP and subsequent coronary artery disease. Cortisol-induced hypertension is normally associated with increased cardiac output. 8 However, increased BP may also be the result of an increase in total peripheral resistance (TPR). Hypertension is strongly associated with endothelial dysfunction 11 and the vasoconstrictor function of the vascular endothelium, such as TPR, has often been studied during the cold pressor test (CPT). 12,13 The CPT induces endothelial dysfunction during which time BP, heart rate (HR) 14 as well as cortisol levels 15 increase. The idea that, especially in the African men, a low-T level may both result from and contribute to increased vascular responses 4 is explored further in the current study, again comparing low-T African and Caucasian subgroups. The aim of this study was to assess the association between BP and T levels during acute and chronic stress. We hypothesize an association between 24 h BP and chronic stress (cortisol, psychological distress) as well as acute stress (cardiovascular) measures during the CPT) in a cohort of South African men stratified into low-T and high-T subgroups. 1 Hypertension in Africa Research Team (HART), Faculty of Health Sciences, North-West University, Potchefstroom, South Africa; 2 Department of Psychology, Technische Universita ¨ t Dresden, Dresden, Germany; 3 Human Neurotransmitters and Neurovascular Hypertension and Kidney Disease Laboratories, Baker IDI Heart and Diabetes Institute and Faculty of Medicine, Nursing and Health Sciences, Monash University, Melbourne, Victoria, Australia and 4 Department of Epidemiology and Public Health, University College of London, London, UK. Correspondence: Dr NT Malan, Hypertension in Africa Research Team (HART), Faculty of Health Sciences, North-West University, Private Bag X6001, Potchefstroom 2520, South Africa. E-mail: nico.malan@nwu.ac.za Received 15 August 2013; revised 14 October 2013; accepted 15 October 2013; published online 28 November 2013 Journal of Human Hypertension (2014) 28, 393–398 & 2014 Macmillan Publishers Limited All rights reserved 0950-9240/14 www.nature.com/jhh