title: Serum levels of insulin-like growth factor-I (IGF-I) and dehydroepiandrosterone sulfate (DHEA-S), and their relationships with serum interleukin-6, in the geriatric syndrome of frailty.
abstract: OBJECTIVE
  The geriatric syndrome of frailty has been conceptualized as a loss of physiologic reserve associated with endocrine dysregulation and immune dysfunction. Our prior studies suggest that the frailty syndrome is associated with elevated serum IL-6 levels. In the present study, our aim is to evaluate the possible role of endocrine dysregulation and its relationship with serum IL-6 in the pathogenesis of this syndrome.
  
  
  METHODS
  Using a recently validated screening algorithm for frailty, we identified 18 frail and 33 non-frail community-dwelling older adults for inclusion in this study. Serum levels of insulin-like growth factor-I (IGF-I), DHEA-S, and IL-6 were measured by immunoassays. The inter-relationships among serum levels of IL-6, DHEA-S, and IGF-I were determined by linear regression analysis.
  
  
  RESULTS
  Age-adjusted serum levels of IGF-I (88+/-49 vs 122+/-47 [ng/mL], p<0.023) and DHEA-S (0.30+/-0.21 vs 0.53+/-0.25 [microg/mL], p=0.016) were significantly lower in frail vs non-frail individuals, respectively. There was a trend for IL-6 to be inversely correlated with IGF-I in the frail (r=-0.42; p=0.082) but not the non-frail group (r=0.12, p=0.521).
  
  
  CONCLUSIONS
  Frail subjects have lower levels of serum IGF-I and DHEA-S and higher levels of IL-6 than do non-frail, age-matched individuals. The trend toward an inverse correlation between IGF-I and IL-6 in the frail, but not the non-frail group, suggests potential interaction between endocrine and immune/cytokine dysregulation that requires further study in larger cohorts.
authors.affiliation: Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors.forename: Sean X
authors.initials: SX
authors.lastname: Leng
authors.forename: Anne R
authors.initials: AR
authors.lastname: Cappola
authors.forename: Ross E
authors.initials: RE
authors.lastname: Andersen
authors.forename: Marc R
authors.initials: MR
authors.lastname: Blackman
authors.forename: Kathleen
authors.initials: K
authors.lastname: Koenig
authors.forename: Michael
authors.initials: M
authors.lastname: Blair
authors.forename: Jeremy D
authors.initials: JD
authors.lastname: Walston
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D001823:Body Composition; D015992:Body Mass Index; D019314:Dehydroepiandrosterone Sulfate / Q000097:blood*; D005260:Female; D016330:Frail Elderly; D015577:Geriatric Assessment / Q000379:methods; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000032:analysis*; D015850:Interleukin-6 / Q000097:blood*; D016014:Linear Models; D008297:Male; D012737:Sex Factors; D018709:Statistics, Nonparametric; D013577:Syndrome; D019282:Wasting Syndrome / Q000097:blood; D044465:White People
chemical_list: D015850:Interleukin-6; D019314:Dehydroepiandrosterone Sulfate; D007334:Insulin-Like Growth Factor I