TY - JOUR
T1 - Effects of acute and chronic stress on the L-arginine nitric oxide pathway in black and white South Africans
T2 - The sympathetic activity and ambulatory blood pressure in Africans study
AU - Reimann, Manja
AU - Hamer, Mark
AU - Malan, Nicolaas T.
AU - Schlaich, Markus P.
AU - Lambert, Gavin W.
AU - Ziemssen, Tjalf
AU - Boeger, Rainer H.
AU - Malan, Leoné
PY - 2013
Y1 - 2013
N2 - Objective: This study investigated the impact of stress on effectors of the L-arginine/nitric oxide (NO) system including the endogenous inhibitor asymmetric dimethylarginine (ADMA). Methods: Black (n = 168) and white (n = 206) South African teachers were exposed to a mental and a physical stressor for 1 minute, respectively. Serum samples for determination of L-arginine, NO metabolites, ADMA, and symmetric dimethylarginine (SDMA) were obtained at rest and during stress exposure. Perception of task stressfulness was assessed on a 7-point Likert scale, and psychological distress was estimated by the General Health Questionnaire. Results: Black South Africans exhibited higher resting levels of NO metabolites (adjusted mean [standard error of the mean] = 11.3 [1.3] versus 3.9 [1.1] μmol/l, p < .001) but lower circulating ADMA (0.62 [0.02] versus 0.70 [0.02] μmol/l, p = .004) and SDMA (0.41 [0.01] versus 0.53 [0.01] μmol/l, p < .001) than did white South Africans. Ethnicity-by-psychological distress interaction was observed for resting levels of ADMA (p = .002), SDMA (p = .038), and L-arginine (p = .048). Ethnic differences in responses to experimental stress were evident for NO metabolites (blacks versus whites: 5.94 [1.55] versus -0.74 [1.25] μmol/l, p = .004) and SDMA (blacks versus whites: -0.02 [0.01] versus 0.02 [0.01] μmol/l, p = .004). Ethnicity-by-psychological distress interaction for stress responses was found for L-arginine/ADMA ratio (p = .027). Conclusions: The L-arginine/NO system is affected by psychosocial distress with higher susceptibility in black South Africans. This interaction may contribute to the higher cardiovascular disease risk in black South Africans.
AB - Objective: This study investigated the impact of stress on effectors of the L-arginine/nitric oxide (NO) system including the endogenous inhibitor asymmetric dimethylarginine (ADMA). Methods: Black (n = 168) and white (n = 206) South African teachers were exposed to a mental and a physical stressor for 1 minute, respectively. Serum samples for determination of L-arginine, NO metabolites, ADMA, and symmetric dimethylarginine (SDMA) were obtained at rest and during stress exposure. Perception of task stressfulness was assessed on a 7-point Likert scale, and psychological distress was estimated by the General Health Questionnaire. Results: Black South Africans exhibited higher resting levels of NO metabolites (adjusted mean [standard error of the mean] = 11.3 [1.3] versus 3.9 [1.1] μmol/l, p < .001) but lower circulating ADMA (0.62 [0.02] versus 0.70 [0.02] μmol/l, p = .004) and SDMA (0.41 [0.01] versus 0.53 [0.01] μmol/l, p < .001) than did white South Africans. Ethnicity-by-psychological distress interaction was observed for resting levels of ADMA (p = .002), SDMA (p = .038), and L-arginine (p = .048). Ethnic differences in responses to experimental stress were evident for NO metabolites (blacks versus whites: 5.94 [1.55] versus -0.74 [1.25] μmol/l, p = .004) and SDMA (blacks versus whites: -0.02 [0.01] versus 0.02 [0.01] μmol/l, p = .004). Ethnicity-by-psychological distress interaction for stress responses was found for L-arginine/ADMA ratio (p = .027). Conclusions: The L-arginine/NO system is affected by psychosocial distress with higher susceptibility in black South Africans. This interaction may contribute to the higher cardiovascular disease risk in black South Africans.
KW - African
KW - Asymmetric dimethylarginine
KW - Cold pressor test
KW - Distress
KW - L-arginine/nitric oxide pathway
UR - http://www.scopus.com/inward/record.url?scp=84886098071&partnerID=8YFLogxK
U2 - 10.1097/PSY.0b013e3182a3e465
DO - 10.1097/PSY.0b013e3182a3e465
M3 - Article
C2 - 23960161
AN - SCOPUS:84886098071
VL - 75
SP - 751
EP - 758
JO - Psychosomatic Medicine
JF - Psychosomatic Medicine
SN - 0033-3174
IS - 8
ER -