title: Defensive coping and subclinical vascular disease risk - associations with autonomic exhaustion in Africans and Caucasians: the SABPA study.
abstract: OBJECTIVE
  The defensive active coping response is a recognised cardiovascular risk factor in Africans, especially in men. It is uncertain whether autonomic dysfunction might be the underlying cause. We therefore investigated associations between salivary MHPG (3-methoxy-4-hydroxyphenolglycol), as a marker of sympathetic activity, and subclinical vascular disease risk in defensive coping Africans and Caucasians.
  
  
  METHODS
  The Coping Strategy Indicator questionnaire identified participants who preferably utilise defensive coping. Ambulatory blood pressure was monitored for 24 h and carotid intima-media thickness (CIMT) was determined from ultrasound images, as an indicator of subclinical vascular disease risk. Salivary MHPG was analysed with high performance liquid chromatography.
  
  
  RESULTS
  Defensive active coping Africans (n = 143) showed overall poorer health than Caucasians (n = 148), with higher self-reported stress, alcohol abuse, hypertension, abdominal obesity, and risk of diabetes (p ≤ 0.05). African women demonstrated lower levels of MHPG compared with Caucasian women, although no differences in men were found. Furthermore, Africans revealed a trend of increased low grade inflammation and glycated haemoglobin which was associated with increased CIMT. There was an inverse association between MHPG and CIMT [β = -0.22 (-0.40, -0.03)], in African men with a high risk of subclinical vascular disease (n = 30).
  
  
  CONCLUSIONS
  Novel findings revealed that defensive active coping Africans are more at risk of subclinical vascular disease, possibly resultant of autonomic exhaustion (decreased MHPG). When defensive coping fails, sympathetic hyperactivity may be followed by autonomic exhaustion and sympatho-adrenal-medullary system desensitisation, resulting in pathology.
authors.affiliation: Hypertension in Africa Research Team (HART), School for Physiology, Nutrition and Consumer Sciences, North-West University, Potchefstroom Campus, Potchefstroom 2520, South Africa.
authors.forename: A
authors.initials: A
authors.lastname: de Kock
authors.forename: L
authors.initials: L
authors.lastname: Malan
authors.forename: M
authors.initials: M
authors.lastname: Hamer
authors.forename: N T
authors.initials: NT
authors.lastname: Malan
mesh_terms: D000223:Adaptation, Psychological; D000328:Adult; D000704:Analysis of Variance; D058070:Asymptomatic Diseases; D001341:Autonomic Nervous System / Q000378:metabolism / Q000503:physiopathology*; D015415:Biomarkers / Q000378:metabolism; D044383:Black People / Q000523:psychology*; D018660:Blood Pressure Monitoring, Ambulatory; D059168:Carotid Intima-Media Thickness; D016009:Chi-Square Distribution; D002851:Chromatography, High Pressure Liquid; D003430:Cross-Sectional Studies; D005260:Female; D015438:Health Behavior / Q000208:ethnology*; D007722:Health Knowledge, Attitudes, Practice / Q000208:ethnology*; D006304:Health Status; D006801:Humans; D016018:Least-Squares Analysis; D008297:Male; D008734:Methoxyhydroxyphenylglycol / Q000378:metabolism; D008875:Middle Aged; D011379:Prognosis; D011446:Prospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D012463:Saliva / Q000378:metabolism; D013019:South Africa / Q000453:epidemiology; D013315:Stress, Psychological / Q000175:diagnosis / Q000208:ethnology* / Q000503:physiopathology; D011795:Surveys and Questionnaires; D014652:Vascular Diseases / Q000175:diagnosis / Q000208:ethnology* / Q000503:physiopathology / Q000523:psychology; D044465:White People / Q000523:psychology*; D055815:Young Adult
chemical_list: D015415:Biomarkers; D008734:Methoxyhydroxyphenylglycol