title: Bone mineral density in systemic lupus erythematosus and its relation to age at disease onset, plasmatic estradiol and immunosuppressive therapy.
abstract: OBJECTIVE
  The aim of this paper was to evaluate bone mineral density (BMD) in patients with systemic lupus erythematosus (SLE), to determine the role of corticosteroids and cytotoxic drugs and to assess estrogen effect on BMD in SLE.
  
  
  METHODS
  BMD (DEXA) at lumbar vertebrae (L2-L4) and at femoral neck was performed in 60 pre-menopausal SLE patients and in 64 controls. Estradiol level was measured in all the individuals. Age, age at disease onset, body mass index (BMI), time of disease, disease activity (SLEDAI), prednisone dose at the evaluation, total cumulative and cumulative prednisone dose in the last year and cytotoxic drugs were assessed.
  
  
  RESULTS
  The mean plasmatic estradiol was 175.9 pg/ml in patients and 149.9 in controls. BMD was inferior in patients than that in controls (P < 0.0001). The mean current, cumulative and previous year prednisone doses were, respectively, 19.17 mg/d, 28.78 g and 5.33 g. There was no association between corticosteroids or cytotoxic drug used and low bone mass. The serum concentration of estradiol did not influence the bone mass. The BMI and age at disease onset exhibited an influence on BMD at L2.
  
  
  CONCLUSIONS
  BMD was significantly lower in SLE patients but not related to CS (Corticosteroids)or other drugs; the estradiol in these patients had no effect on BMD. Low BMI interacting with early onset of disease might influence the probability of loss of bone mass.
authors.affiliation: Rheumatology Unit, Department of Internal Medicine, Faculty of Medical Sciences, State University of Campinas, Brazil.
authors.forename: Ibsen Bellini
authors.initials: IB
authors.lastname: Coimbra
authors.forename: Lilian Tereza Lavras
authors.initials: LT
authors.lastname: Costallat
mesh_terms: D015502:Absorptiometry, Photon; D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D015992:Body Mass Index; D015519:Bone Density; D002648:Child; D004958:Estradiol / Q000097:blood*; D005260:Female; D005272:Femur Neck / Q000000981:diagnostic imaging; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use*; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging; D008180:Lupus Erythematosus, Systemic / Q000188:drug therapy / Q000453:epidemiology / Q000378:metabolism; D008875:Middle Aged; D011241:Prednisone; D017697:Premenopause; D012720:Severity of Illness Index
chemical_list: D007166:Immunosuppressive Agents; D004958:Estradiol; D011241:Prednisone