title: Low graft function and ongoing hyperparathyroidism are closely related to post-transplantation osteoporosis.
abstract: BACKGROUND
  Renal transplantation (RT) is the gold standard therapy for chronic renal failure. Immunosuppressive drug choice, malnutrition, adynamic bone disease and hyperparathyroidism are important factors impacting the development of posttransplant osteoporosis. Body composition analysis with bioimpedance devices (BIA) is a useful noninvasive tool to detect malnutrition among the RT population. We investigated the effects of graft function, immunosuppressive drug regimens and biochemical characteristics on bone mineral density of RT patients as well as the reliability of BIA measurements to diagnose osteoporosis.
  
  
  METHODS
  One hundred three recipients with a minimum of 12 months post-RT follow-up underwent body composition analysis using the Tanita Analyzer. The last 6 months of monthly biochemical parameters and glomerular filtration rates (GFR) as well as drug regimens were collected retrospectively from patient charts. Patients were divided into 2 groups, according to their femoral neck and lumbal T scores, as osteoporosis (n = 42) and control groups (n = 61).
  
  
  RESULTS
  The mean GFR of osteoporotic patients was significantly lower (P = .04) and parathyroid hormone (PTH) levels significantly higher (P = .002). According to BIA, osteoporotic patients showed lower bone mass, fat mass, visceral fat ratio, muscle mass, waist-hip ratios, and body mass index values (P < .05). Correlation analysis revealed GFR to negatively correlate with PTH (r = -0.231, P = .010) and positively with femur t scores (r = 0.389, P = .0001) as well as with BIA findings (P = .0001). In contrast, PTH levels in negatively correlated with lumbar and femoral neck t scores (r = -0.22, -0.4 and P = .026, .0001, respectively) but not with BIA findings including bone mass.
  
  
  CONCLUSIONS
  Changes in bone density after RT were affected by graft function. The rapid loss of bone mineral density emphasizes the need for prevention started in the early posttransplant period. BMD measurements provided a guide for treatment and for subsequent evaluation.
authors.affiliation: Department of Nephrology, Başkent University Medical School, Ankara, Turkey. emretutal@gmail.com
authors.forename: E
authors.initials: E
authors.lastname: Tutal
authors.forename: M E
authors.initials: ME
authors.lastname: Uyar
authors.forename: T
authors.initials: T
authors.lastname: Colak
authors.forename: Z
authors.initials: Z
authors.lastname: Bal
authors.forename: B G
authors.initials: BG
authors.lastname: Demirci
authors.forename: T
authors.initials: T
authors.lastname: Bozkurt
authors.forename: S
authors.initials: S
authors.lastname: Sezer
authors.forename: F N O
authors.initials: FN
authors.lastname: Acar
mesh_terms: D000328:Adult; D001823:Body Composition; D005260:Female; D005919:Glomerular Filtration Rate; D006085:Graft Survival; D006801:Humans; D006961:Hyperparathyroidism / Q000150:complications* / Q000503:physiopathology; D007166:Immunosuppressive Agents / Q000008:administration & dosage / Q000009:adverse effects; D016030:Kidney Transplantation; D008297:Male; D008875:Middle Aged; D010024:Osteoporosis / Q000150:complications* / Q000503:physiopathology
chemical_list: D007166:Immunosuppressive Agents