title: Nitric oxide synthesis capacity, ambulatory blood pressure and end organ damage in a black and white population: the SABPA study.
abstract: Nitric oxide (NO) synthesis capacity is determined by the availability of substrate(s) such as L-arginine and the influence of nitric oxide synthase (NOS) inhibitors, asymmetric dimethylarginine (ADMA) and symmetric dimethylarginine (SDMA). These factors may be important in black South Africans with a very high prevalence of hypertension. We compared ambulatory blood pressure (BP), markers of end organ damage and NO synthesis capacity markers [L-arginine, L-homoarginine, L-citrulline, L-arginine:ADMA, ADMA, SDMA and dimethylarginine (DMA)], between black and white teachers (n = 390). Associations of nighttime BP and markers of end organ damage with NO synthesis capacity markers were also investigated. Although black men and women had higher BP and albumin-to-creatinine ratio (ACR) (all p < 0.001), they also had higher L-arginine, L-homoarginine, L-arginine:ADMA and lower SDMA and DMA levels (all p < 0.05). Only in white men ADMA concentrations associated positively with nighttime systolic blood pressure (R (2) = 0.20, β = 0.26, p = 0.009), nighttime diastolic blood pressure (R (2) = 0.23, β = 0.27, p = 0.007), carotid intima media thickness (cIMT) (R (2) = 0.36, β = 0.22, p = 0.008) and ACR (R (2) = 0.14, β = 0.32, p = 0.001). Our findings suggest that despite an adverse cardiovascular profile in blacks, their NO synthesis capacity profile seems favourable, and that other factors, such as NO inactivation, may prove to be more important.
authors.affiliation: Hypertension in Africa Research Team (HART), North West University, Private Bag x6001, Potchefstroom, 2520, South Africa. carina.mels@nwu.ac.za.
authors.forename: Catharina M C
authors.initials: CMC
authors.lastname: Mels
authors.affiliation: Hypertension in Africa Research Team (HART), North West University, Private Bag x6001, Potchefstroom, 2520, South Africa.
authors.forename: Ilisma
authors.initials: I
authors.lastname: Loots
authors.affiliation: Department of Clinical Pharmacology and Toxicology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
authors.forename: Edzard
authors.initials: E
authors.lastname: Schwedhelm
authors.affiliation: Department of Clinical Pharmacology and Toxicology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.|Radcliffe Department of Medicine, University of Oxford, Oxford, UK.
authors.forename: Dorothee
authors.initials: D
authors.lastname: Atzler
authors.affiliation: Department of Clinical Pharmacology and Toxicology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
authors.forename: Rainer H
authors.initials: RH
authors.lastname: Böger
authors.affiliation: Hypertension in Africa Research Team (HART), North West University, Private Bag x6001, Potchefstroom, 2520, South Africa.|MRC Research Unit for Hypertension and Cardiovascular Disease, North-West University, Private bag X6001, Potchefstroom, 2522, South Africa.
authors.forename: Aletta E
authors.initials: AE
authors.lastname: Schutte
mesh_terms: D000328:Adult; D000368:Aged; D001120:Arginine / Q000031:analogs & derivatives / Q000097:blood; D015415:Biomarkers / Q000097:blood; D044383:Black People; D001794:Blood Pressure; D059168:Carotid Intima-Media Thickness; D002956:Citrulline / Q000097:blood; D003430:Cross-Sectional Studies; D005260:Female; D006709:Homoarginine / Q000097:blood; D006801:Humans; D006973:Hypertension / Q000208:ethnology / Q000378:metabolism* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D009569:Nitric Oxide / Q000096:biosynthesis*; D013020:South America / Q000208:ethnology; D044465:White People
chemical_list: D015415:Biomarkers; C487735:dimethylarginine; D006709:Homoarginine; D002956:Citrulline; D009569:Nitric Oxide; D001120:Arginine
keywords: ADMA; African; Carotid intima media thickness; Endothelial function; Estimated glomerular filtration rate; Ethnicity; Hypertension; L-arginine; L-citrulline; L-homoarginine; Nighttime blood pressure; Renal function; SDMA; Urinary albumin-to-creatinine ratio