title: Aromatase inhibitor-induced loss of grip strength is body mass index dependent: hypothesis-generating findings for its pathogenesis.
abstract: BACKGROUND
  Our preliminary results showed that tenosynovial changes and decrease in grip strength are associated with the aromatase inhibitor-induced musculoskeletal syndrome (AIMSS). Here, we report the final results and assess the relationship between grip strength and body mass index (BMI).
  
  
  METHODS
  We conducted a prospective study including postmenopausal early breast cancer patients receiving either an aromatase inhibitor (AI) or tamoxifen. Primary end point was change from baseline in tenosynovial abnormalities. Secondary end points were changes from baseline in morning stiffness, intra-articular fluid and grip strength and its association with BMI.
  
  
  RESULTS
  After 6 months of therapy, 74% [95% confidence interval (CI) 51% to 89%] of AI-treated patients had worsened tenosynovial abnormalities, 56% (95% CI 34% to 75%) had increased intra-articular fluid, and 22% (95% CI 9% to 45%) had increased morning stiffness. Grip strength decreased 8% for the left hand (95% CI 2% to 21%) and 11% for the right (95% CI 4% to 17%). Regression analysis suggested that grip strength decreased more for subjects with high or with low BMI.
  
  
  CONCLUSIONS
  AIMSS is characterized by tenosynovial changes, intra-articular fluid and morning stiffness. We hypothesize that the quadratic association between BMI and loss of grip strength reflects AI-induced changes on the endocrine control of the growth hormone insulin-like growth factor-I pathway.
authors.affiliation: Department of Obstetrics & Gynecology, Division of Gynecological Oncology, University Hospitals Leuven, Belgium. anneleen.lintermans@uzleuven.be
authors.forename: A
authors.initials: A
authors.lastname: Lintermans
authors.forename: B
authors.initials: B
authors.lastname: Van Calster
authors.forename: M
authors.initials: M
authors.lastname: Van Hoydonck
authors.forename: S
authors.initials: S
authors.lastname: Pans
authors.forename: J
authors.initials: J
authors.lastname: Verhaeghe
authors.forename: R
authors.initials: R
authors.lastname: Westhovens
authors.forename: N L
authors.initials: NL
authors.lastname: Henry
authors.forename: H
authors.initials: H
authors.lastname: Wildiers
authors.forename: R
authors.initials: R
authors.lastname: Paridaens
authors.forename: A S
authors.initials: AS
authors.lastname: Dieudonné
authors.forename: K
authors.initials: K
authors.lastname: Leunen
authors.forename: L
authors.initials: L
authors.lastname: Morales
authors.forename: K
authors.initials: K
authors.lastname: Verschueren
authors.forename: D
authors.initials: D
authors.lastname: Timmerman
authors.forename: L
authors.initials: L
authors.lastname: De Smet
authors.forename: I
authors.initials: I
authors.lastname: Vergote
authors.forename: M R
authors.initials: MR
authors.lastname: Christiaens
authors.forename: P
authors.initials: P
authors.lastname: Neven
mesh_terms: D000368:Aged; D000077384:Anastrozole; D000730:Androstadienes / Q000009:adverse effects / Q000627:therapeutic use; D047072:Aromatase Inhibitors / Q000009:adverse effects* / Q000627:therapeutic use; D018771:Arthralgia / Q000139:chemically induced / Q000503:physiopathology; D015992:Body Mass Index; D001943:Breast Neoplasms / Q000188:drug therapy*; D015331:Cohort Studies; D005260:Female; D018737:Hand Strength; D006801:Humans; D000077289:Letrozole; D008875:Middle Aged; D009140:Musculoskeletal Diseases / Q000139:chemically induced* / Q000503:physiopathology; D009376:Neoplasms, Hormone-Dependent / Q000188:drug therapy*; D009570:Nitriles / Q000009:adverse effects / Q000627:therapeutic use; D017698:Postmenopause; D013577:Syndrome; D013629:Tamoxifen / Q000009:adverse effects / Q000627:therapeutic use; D014230:Triazoles / Q000009:adverse effects / Q000627:therapeutic use
chemical_list: D000730:Androstadienes; D047072:Aromatase Inhibitors; D009570:Nitriles; D014230:Triazoles; D013629:Tamoxifen; D000077384:Anastrozole; D000077289:Letrozole; C056516:exemestane