Plasma amino acid patterns during supplemental intravenous nutrition of low-birth-weight infants.

In 42 low-birth-weight infants (smaller than 1,200 gm), we have compared the effects of intravenous nutrition supplement versus conventional feedings on growth, morbidity, mortality, and plasma amino acid patterns. Despite similar total caloric intake in INS and control groups, weight gain was greater in the INS infants. The overall mortality rate did not differ in the two groups. Nonsurviving infants receiving INS lived longer (mean equal to 30 days) than nonsurviving CON infants (mean equal to 5 days). Complications were equally frequent in both groups except that hyperglycemia occurred more often in infants receiving INS. The plasma aminogram of the LBW infant is described and compared to those of the full-term infant and adult. Hypoaminoacidemia was present at birth in the LBW infants, concentrations of glutamine, alamine, glycine, histidine, and ornithine being significantly (P smaller than 0.05) below FT values. During INS, elevations of threonine, serine, and methionine above FT values occurred. Glutamine remained subnormal despite INS. Recommendations for an INS solution more suitable for use in LBW infants are presented.

Observations on the responsiveness of human subjects to human growth hormone. Effects of endogenous growth hormone deficiency and myotinic dystrophy.

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.