Assessment of hydration by means of bioelectrical impedance and arm muscle area during growth hormone (GH) replacement therapy: A prospective study of 130 GH-deficient patients.
OBJECTIVE
Growth hormone (GH)-deficiency is associated with a reduced extracellular volume (ECV), whereas GH replacement may cause fluid retention. We have tested a simple method to assess hydration in GH-deficient patients (GHD) based on concomitant measurements of body resistance by bioelectrical impedance analysis (BIA), and arm muscle area (AMA).


METHODS
We prospectively followed 130 patients (54 females, 76 males) with adult-onset GHD before and during 1-5 years GH replacement therapy.


METHODS
Concomitant measurements of body resistance and AMA were done on four occasions: before treatment, after one month and one year of treatment, and at the most recent visit. Based on normative data obtained in 142 women and 84 men an inverse relationship was documented between body resistance and AMA. Assuming that linear height and the concentration of electrolytes remain constant, body resistance at a given AMA will reflect specific hydration.


RESULTS
In the patients a gender-specific inverse correlation between body resistance and AMA existed, which was different from the control group and changed during GH replacement. A deviation between predicted (based on normative data) and measured body resistance at a given AMA was recorded in the patients before and during therapy compatible with relative dehydration in the untreated state followed by an increase in hydration during therapy.


CONCLUSIONS
Concomitant measurements of BIA and AMA in GHD patients may provide a non-invasive and simple means to estimate hydration before and during GH replacement.
Badre-Esfahani
Sara
S
Medical Department M (Endocrinology and Diabetes), Aarhus University Hospital, Nørrebrograde 44, DK-8000 C Aarhus, Denmark.
Nellemann
Birgitte
B
Danielsen
Ditte
D
Fisker
Sanne
S
Christiansen
Jens Sandahl
JS
Jørgensen
Jens Otto Lunde
JO
D000328:Adult; D001132:Arm / Q000502:physiology; D001823:Body Composition; D017097:Electric Impedance; D045604:Extracellular Fluid; D005260:Female; D013006:Growth Hormone / Q000009:adverse effects* / Q000172:deficiency* / Q000627:therapeutic use; D020249:Hormone Replacement Therapy / Q000009:adverse effects*; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000032:analysis; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000502:physiology; D014869:Water Intoxication / Q000139:chemically induced / Q000175:diagnosis*
D007334:Insulin-Like Growth Factor I; D013006:Growth Hormone