title: Albuminuria is associated with hip fracture risk in older adults: the cardiovascular health study.
abstract: The microcirculation plays an important role in bone health. Here, we examine whether albuminuria, a marker of renal microvascular disease, is associated with the risk of hip fracture in older adults (age, 78 years). We find a small independent association in women but not in men.
  
  
  BACKGROUND
  The microvascular circulation plays an important role in bone physiology. Two studies of middle-aged adults have found that albuminuria (>30 mg albumin/g creatinine), a disorder of the renal microvasculature, is associated with fracture risk. Here, we examine whether albuminuria is related to hip fracture risk and reduced hip bone mineral density (BMD) in older adults with a mean age of 78 years.
  
  
  METHODS
  From the Cardiovascular Health Study (41 % male), 3,110 adults with albuminuria testing were followed up for incident hip fracture for up to 9.5 years. BMD was performed in a subset of 1,208 participants.
  
  
  RESULTS
  There were 313 hip fractures during follow-up (7.7 % of men; 11.7 % of women). The incidence rate for men, with and without albuminuria, was 1.43 and 0.93/100 person-years of follow-up (p = 0.02); for women, 1.84 and 1.33 (p = 0.04). After adjustment for osteoporosis-related factors, frailty and falling, a doubling of albuminuria was significantly associated with hip fracture risk in women (hazard ratio, 1.12, 95 % CI, 1.001-1.25), but not in men. In the subcohort with BMD measurement, increased urine albumin levels were significantly associated with decreased total hip BMD in men (-0.009 g calcium/cm(2) (-0.017, -0.001); p = 0.04), but not in women.
  
  
  CONCLUSIONS
  In older women, albuminuria is associated with a small, but statistically significant, increased risk of hip fracture independent of other explanatory factors. No such risk appears to be present in men, although their total hip BMD is lower in association with albuminuria.
authors.affiliation: Division of Endocrinology, Kaiser Permanente of Georgia, Atlanta, GA, USA, joshua.barzilay@kp.org.
authors.forename: J I
authors.initials: JI
authors.lastname: Barzilay
authors.forename: P
authors.initials: P
authors.lastname: Bůžková
authors.forename: Z
authors.initials: Z
authors.lastname: Chen
authors.forename: I H
authors.initials: IH
authors.lastname: de Boer
authors.forename: L
authors.initials: L
authors.lastname: Carbone
authors.forename: N N
authors.initials: NN
authors.lastname: Rassouli
authors.forename: H A
authors.initials: HA
authors.lastname: Fink
authors.forename: J A
authors.initials: JA
authors.lastname: Robbins
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000419:Albuminuria / Q000150:complications* / Q000453:epidemiology / Q000503:physiopathology; D015519:Bone Density / Q000502:physiology; D005260:Female; D005500:Follow-Up Studies; D006620:Hip Fractures / Q000453:epidemiology / Q000209:etiology* / Q000503:physiopathology; D006621:Hip Joint / Q000503:physiopathology; D006801:Humans; D015994:Incidence; D053208:Kaplan-Meier Estimate; D008297:Male; D058866:Osteoporotic Fractures / Q000453:epidemiology / Q000209:etiology* / Q000503:physiopathology; D012307:Risk Factors; D012737:Sex Factors; D014481:United States / Q000453:epidemiology