Search

Metabolic balance studies were conducted in seven boys with Duchenne-type muscular dystrophy, and in six normal boys of similar age, during a 12 day control period and during a 12 day period of treatment with human growth hormone (HGH) at the following doses: 0.0168, 0.0532, and 0.168 U/kg body weight (BW)((3/4)) per day (doses A, B, and C, respectively). In five of the six normals, dose C caused positive balances in N, P, Na, and K; doses B and A had anabolic effects in two and one normal subjects, respectively. In six of the seven Duchenne cases, dose C caused negative balances of N and K, and sometimes of P. Negative balances were produced in three of the Duchenne subjects by dose B, and in one by dose A. None of the dystrophy cases exhibited an anabolic response to any dosage of HGH tested. The release of endogenous HGH in response to insulin, after 2 days' pretreatment with diethylstilbestrol, was similar in both groups of subjects. In the course of these tests, a marked anabolic effect of diethylstilbestrol in the Duchenne patients was apparent. Therefore metabolic balance studies were repeated, in both Duchenne and normal cases, during a 12 day control period and during 12 days of treatment with diethylstilbestrol (0.106 mg/kg BW((3/4)) per day). In three of the normal children, diethylstilbestrol had no effect on the elemental balances; in two cases, a retention of Na was observed. In all seven Duchenne cases, diethylstilbestrol caused positive balances in N, P, Na, and K. Ethinyl estradiol (0.0106 mg/kg BW((3/4)) per day) produced positive N, P, Na, and K balances in all three Duchenne cases tested with this agent. The data show that exogenous HGH causes a catabolic effect in boys with Duchenne dystrophy. These patients are hyperresponsive to the anabolic effect of diethylstilbestrol. The latter phenomenon may reflect the inhibitory effect of estrogen upon the peripheral actions of these boys' endogenous HGH.

The effect of human growth hormone (HGH) on the N, P, Na, and K balance, and on the body weight (BW) of three groups of subjects was measured. In group I were nine cases (age 6-69) with HGH deficiency; in group II, eight cases (age 9-79) with normal endogenous HGH; in group III, four cases with myotonic dystrophy (age 45-51). After a 7 day control period, the hormone was administered for 7 days. Each subject was tested with three doses of HGH: dose A, 0.0168 U/kg BW(3/4) per day; dose B, 0.0532 U/kg BW(3/4) per day; dose C, 0.168 U/kg BW(3/4) per day. In group I, the responsiveness to HGH declined with age. Two subjects aged 6 yr responded to all three doses of HGH with positive balances in N, P, Na, and K and increases in BW. At ages 15-17, responses were obtained only to doses B and C in three cases, and only to dose C in two cases. Two subjects, aged 42 and 69, responded only to dose C. Not only did the threshold dose increase with age in group I, but the magnitude of the responses declined with age as well.Patients of group II were less responsive to all doses of HGH than were patients of group I at comparable age. None responded to dose A or dose B. All responded to dose C, but the increments in balances and in BW stimulated by this dose were only one-third to one-half as great as in HGH-deficient subjects of similar age. Three patients of group III responded to all three doses of HGH, and one responded to doses B and C. The responses were similar in magnitude to those in the 6-yr old HGH-deficient children, and greater than those in all other subjects studied. These data show that responsiveness to exogenous HGH rises with deficiency of endogenous HGH, and that individuals with myotonic dystrophy are hyperresponsive to exogenous HGH.