title: Homoarginine in patients with primary hyperparathyroidism.
abstract: BACKGROUND
  Low levels of the amino acid homoarginine and parathyroid hormone (PTH) excess are both independently related to an increased risk of cardiovascular morbidity and mortality. Accumulating evidence points to a mutual interplay between homoarginine and PTH. The authors therefore aimed to investigate circulating homoarginine levels in patients with and without primary hyperparathyroidism (PHPT).
  
  
  METHODS
  The authors performed a cross-sectional analysis of serum homoarginine levels in 59 patients with mild and severe PHPT and in 92 control persons matched for age, sex and estimated glomerular filtration rate.
  
  
  RESULTS
  Median PTH and serum homoarginine concentrations were 99.1 (79.7-120.2) pg/mL and 1.16 (0.95-1.66) µmol/L in patients with PHPT (79.7% female; 42.4% with normocalcemia) as compared with 45.8 (36.4-53.9) pg/mL and 1.62 (1.33-2.04) µmol/L in the control group (P < 0.001 for both), respectively. The authors observed no statistically differences between cases and controls for 25-hydroxyvitamin D [25(OH)D], serum albumin, hemoglobin, waist-to-hip ratio, C-reactive protein and NT-pBNP values. Multivariate analysis of covariance revealed that patients with PHPT had significantly lower homoarginine levels than controls (P < 0.001). This difference remained significant after adjusting for multiple confounders such as 25(OH)D, body mass index, LDL cholesterol, albumin, calcium, hemoglobin, smoking status and current antihypertensive medication. The differences of homoarginine levels persisted even after exclusion of patients with estimated glomerular filtration rate <60 mL/min (P = 0.003) and 25(OH)D levels <30 ng/mL (P = 0.001), respectively.
  
  
  CONCLUSIONS
  Patients with PHPT have lower homoarginine levels compared with matched controls irrespective of age, sex, kidney function and 25(OH)D status. Further studies are needed to evaluate whether low homoarginine accounts for higher cardiovascular risk conferred by PTH excess.
authors: Department of Cardiology (AT, NV, BP, EK-K, CC, AS, EB), Medical University of Graz, Graz, Austria; Specialist Clinic for Rehabilitation PV Bad Aussee (AT, JR-M), Bad Aussee, Austria; Medizinische Klinik mit Schwerpunkt Kardiologie (AT, BP, EK-K), Campus Virchow-Klinikum, Charité-Universitaetsmedizin Berlin, Berlin, Germany; Division of Endocrinology and Metabolism, Department of Internal Medicine (MG, CS, KA, AF-P, SP), Medical University of Graz, Graz, Austria; Clinical Institute of Medical and Chemical Laboratory Diagnostics (AM, WM), Medical University of Graz, Graz, Austria; Synlab-Academy (WM), Synlab services LLC, Mannheim, Germany; Medical Clinic V (Nephrology, Hypertensiology, Endocrinology, Diabetology, Rheumatology) (WM), Ruperto Carola University Heidelberg, Medical Faculty Mannheim, Mannheim, Germany; Department of Epidemiology and Biostatistics (AJvB) and EMGO Institute for Health and Care Research, VU University Medical Center, Amsterdam, the Netherlands; and Department of Medicine, Division of Nephrology (ER), University Hospital Heidelberg, Heidelberg, Germany.
authors: Andreas
authors: A
authors: Tomaschitz
authors: Nicolas
authors: N
authors: Verheyen
authors: Martin
authors: M
authors: Gaksch
authors: Andreas
authors: A
authors: Meinitzer
authors: Burkert
authors: B
authors: Pieske
authors: Elisabeth
authors: E
authors: Kraigher-Krainer
authors: Caterina
authors: C
authors: Colantonio
authors: Winfried
authors: W
authors: März
authors: Albrecht
authors: A
authors: Schmidt
authors: Evgeny
authors: E
authors: Belyavskiy
authors: Jutta
authors: J
authors: Rus-Machan
authors: Adriana J
authors: AJ
authors: van Ballegooijen
authors: Claudia
authors: C
authors: Stiegler
authors: Karin
authors: K
authors: Amrein
authors: Eberhard
authors: E
authors: Ritz
authors: Astrid
authors: A
authors: Fahrleitner-Pammer
authors: Stefan
authors: S
authors: Pilz
mesh_terms: D000368:Aged; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D005260:Female; D006709:Homoarginine / Q000097:blood*; D006801:Humans; D049950:Hyperparathyroidism, Primary / Q000097:blood*; D008297:Male; D010281:Parathyroid Hormone / Q000097:blood; D014807:Vitamin D / Q000031:analogs & derivatives / Q000097:blood
chemical_list: D010281:Parathyroid Hormone; D014807:Vitamin D; D006709:Homoarginine; C104450:25-hydroxyvitamin D