title: Nocturnal blood pressure, 3-methoxy-4-hydroxyphenylglycol and carotid intima-media thickness: The SABPA study.
abstract: BACKGROUND
  Research demonstrated a significant relationship between elevated nocturnal blood pressure and sympathetic hyperactivity. The study aimed to investigate possible associations between norepinephrine metabolite, 3-methoxy-4-hydroxyphenylglycol (MHPG), nocturnal BP and carotid intima-media thickness (CIMT) in urban African and Caucasian men.
  
  
  METHODS
  The study included 82 African and 100 Caucasian male teachers, aged 33-56 years, recruited in the North-West Province, South Africa. Ambulatory BP and fasting saliva and blood samples were collected. B-mode ultrasound images were obtained to determine CIMT.
  
  
  RESULTS
  Despite higher usage of anti-hypertensive medication usage (p=0.039), a large number of the African men were nocturnal hypertensives (75, 61%). The nocturnal systolic blood pressure (SBP) (p<0.001), diastolic blood pressure (DBP) (p<0.001) and heart rate (p<0.001) of the African men were higher. After stratifying groups into only nocturnal hypertensives the trend was the same (SBP p<0.001; DBP p<0.001; heart rate p=0.058). In the African and Caucasian men, CIMT was linearly predicted by SBP (β=0.33, p<0.001) and DBP (β=0.24, p=0.016) respectively, but not MHPG.
  
  
  CONCLUSIONS
  No associations were firstly demonstrated between MHPG as sympathetic activity marker and CIMT or secondly, between MHPG and nocturnal blood pressure. Novel findings of elevated nocturnal BP evidently seem to promote structural vascular disease in urban African and Caucasian men.
authors: Hypertension in Africa Research Team (HART), North-West University, Potchefstroom Campus, South Africa.
authors: Aletta S
authors: AS
authors: Uys
authors: Leoné
authors: L
authors: Malan
authors: Johannes M
authors: JM
authors: van Rooyen
authors: Hendrik S
authors: HS
authors: Steyn
authors: Tjalf
authors: T
authors: Ziemssen
authors: Manja
authors: M
authors: Reimann
mesh_terms: D000328:Adult; D000959:Antihypertensive Agents / Q000008:administration & dosage; D001342:Autonomic Nervous System Diseases / Q000097:blood; D015415:Biomarkers / Q000097:blood; D044383:Black People; D001794:Blood Pressure; D059168:Carotid Intima-Media Thickness; D006801:Humans; D008297:Male; D008734:Methoxyhydroxyphenylglycol / Q000097:blood*; D008875:Middle Aged; D012463:Saliva / Q000378:metabolism; D013019:South Africa; D014505:Urban Population; D044465:White People
chemical_list: D000959:Antihypertensive Agents; D015415:Biomarkers; D008734:Methoxyhydroxyphenylglycol
keywords: 3-Methoxy-4-hydroxyphenylglycol; African; Carotid intima-media thickness; Caucasian; Nocturnal blood pressure