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Acute symptomatic ketoacidosis following growth hormone administration in prolonged fasting
Acute Symptomatic Ketoacidosis Following Growth Hormone Administration in Prolonged Fasting By ERNST J. DRENICK,ERNEST M. GOLD AND HAROLDELRICK Human growth hormone (HGH) was administered to four obese males after fasts of 26 to 52 days. Within hours after the injection severe postural hypotension, faintness, nausea, vomiting and muscle cramps developed. Improvement occurred spontaneously despite continued fasting. In most instances, serum FFA and ketones rose and blood CO2 content fell, suggesting an exaggeration of the preexisting fasting acidosis. Urinary losses of Na, Ca, Mg and phosphate increased along with a rise in titratable acidity. A concomitant expansion of the exchange-
able Na pool suggested mobilization of Na from storage sites, presumably bone. It appears that the precarious clinical adjustment peculiar to prolonged fasting is disturbed by the increasing ketosis resulting from the calorigenic stimulus and lipolytic effect of HGH. Mineral losses and the mobilization of sodium are a sequel to the accentuation of the acidosis and the clinical symptoms result from the redistribution of water and electrolytes among body compartments in marginally depleted subjects. (Metabolism 19: No. 8, August, 60&613, 1970)
OBESE SUBJECTS metabolize sizable quantities of body protein in addition to fat. Although the daily protein loss diminishes with prolonged fasting, anabolic agents have been administered in an attempt to further reduce protein catabo1ism.l Because endogenous growth hormone falls to very low levels during extended fasts,“-4 exogenous HGH may have anabolic activity and, additionally, promote lipolysis. When HGH was administered to obese subjects in pharmacologic doses during prolonged fasts, several unexpected effects were observed. The untoward clinical manifestations, the changes in serum chemistry and the striking alterations in renal excretion of various ions are presented and discussed.
F
ASTING
MATERIALS AND METHODS Four obese but otherwise healthy males were studied. They weighed from 126 to 164 Kg. on admission to a metabolic ward. Their ages ranged from 39 to 51 years. During the fast, tap water was allowed ad lib. One multivitamin tablet, 2 Cm. of Probenecid and 2 Cm. of potassium chloride were administered daily. Except for a constant rate of weight loss and a mild degree of postural hypotension, the subjects were clinically stable and well. All were ketotic and manifested a mild metabolic acidosis. Fasting periods had lasted from 26 to 52 days when 12-18 mg. of HGH was administered by intramuscular injection. Three subjects received a single dose and one was given 18 mg. injections daily for five days. From the Veterans Administratiotl Center, Los Angeles, Calif. Received for publication March 20, 1970. Supported in part by an NIH grant. ERNEST J. DRENICK, M.D.: Veterans Administration Cenfer, Los Angeles, Calif.: Associate Professor, UCLA Medical School, Los Angeles, Catif. ERNEST M. GOLD, M.D.: Veterans Administration Center. Los Angeles, Calif.: Assistant Professor, UCLA Medical School, Los Angeles, Calif. HAROLD ELRICK, M.D.: Director, Metabolic Clinic, Mercy HOSpital, Sun Diego, Calif. 608
METABOLISM,
VOL. 19, No. 8 (AUGUST),
1970
ACUTE SYMPTOMATICKETOACIDOSIS
609
The HGH administered in this study was prepared by the method of Elrick et al.5 One milligram of the hormone approximated 1 USP unit by bioassay. The lyophilized hormone was dissolved in 0.5 ml. of 0.1 N NaOH and diluted to 1.0 ml. with sterile saline on the morning of the injection. In three subjects a biologically inactive preparation was injected which failed to evoke any responses. An active preparation was given in a second trial to one of these three subjects with the anticipated results. Serum was analyzed daily or at suitable intervals before and following HGH. Glucose, free fatty acids, creatinine, uric acid, electrolytes and total ketoacids were measured. Urine was collected in 24-hour pools before and following the injection. Sodium, potassium, calcium, phosphorus, titratable acidity, ketones, nitrogen and creatinine were measured quantitatively. The methods have been described previously. 6 In two subjects, exchangeable sodium was measured by isotope dilution utilizing the method described by Edelman7 on the day before and 24 hours after the injection of HGH. 22Na was used as a tracer. Under comparable experimental conditions, this method has given reliable and reproducible results with p values of < .OOl. Because of clinical complications and because concomitant analyses exhausted the supply of various specimens, not all of the measurements cited were carried out in each subject on each day of observation.
RESULTS Clinical Course
All four subjects developed weakness, dizzyness, muscle cramps and a marked accentuation of a pre-existing postural hypotension within 8 to 24 hours after HGH. All four subjects became nauseated and vomited. Syncope occurred in one patient. From the second day on, symptoms gradually improved and subsided after the third day, despite continuation of the fast. This was also true for the one subject in whom HGH was continued for five days. Weight loss was accelerated beyond the expected rate of 1 pound/day to a maximum loss of 15 pounds in three days as a result of a greatly increased urine output. Serum
Moderately elevated FFA concentrations in the serum rose further in two of three subjects and ketoacids increased in two of two subjects following the HGH injections. COZ which was lowered before HGH manifested a significant decline in two subjects. One subject (K) who manifested no change in FFA failed to develop a convincing fall in bicarbonate concentration (Fig. 1). The changes were transient and a spontaneous return to original levels occurred within three to five days. Blood glucose, serum creatinine, cholesterol and uric acid levels remained unchanged. The serum concentration of sodium, potassium, calcium, phosphorus and magnesium remained normal and unaltered. Urine
Urinary eIectrolyte excretion underwent marked but transient changes following HGH (Fig. 2). Sodium conservation during fasting is generally very efficient and after the first two weeks only minute quantities ( < 3-5 mEq./day) are excreted unless sodium supplements are furnished. HGH provoked a prompt natriuresis in all subjects. The loss was marked on the day of administration of HGH and maximal on the following day. Potassium losses followed a
610
DRENICK,
GOLD AND ELRICK
Fig. l.-Changes in serum levels following HGH are indicative of increased lipolysis and ketoacidosis. Each curve represents changes for one subject. (Individual subjects are identified by their initials.)
0
, -1
24,HR
1 I
URINE
,
’
DA&
ELECTROLYTES
K (mEq)
DAYS
3
4
ACUTE
SYMPTOMATIC
611
KETOACIDOSIS
24 H&URINARY
EXCRETION
Fig. 3.-Increased urinary nitrogen following HGH suggests enhanced protein catabolism. NITROGEN (pm)
-I
!
I
I
2 DAYS
3
4
similar pattern. Calcium and magnesium excretion rose to a lesser degree. Urinary phosphorus increased markedly. Figure 3 shows that urinary nitrogen losses in three of four subjects increased to nearly twice the pre-HGH levels. Commensurate increments in creatinine excretion were noted. Changes in the pattern of urinary ketone excretion, determined in only two subjects, were inconsistent and, in the same subjects, titratable acidity increased substantially on the day of the HGH injection. Exchangeable
Sodium
Within eight hours after HGH, exchangeable sodium rose from 3222 to 3759 in one subject and from 3596 to 4537 mEq. in the other. This rise coincided with the appearance of various clinical ill effects. DISCUSSION
Normally the administration of HGH results in a positive nitrogen balance and in retention of potassium, sodium and phosphorus. The calcium balance may become positive, though usually urinary calcium excretion rises.8-10 HGH causes a rise in serum FFA levels .3J1J2 A calorigenic effect in the lean and in the obese had been described.1°J3 In short fasts (48 hours) HGH administration enhanced the fasting ketosis and produced an exaggerated rise in serum FFA.14 No adverse clinical sequelae were described under these circumstances, but in normal, fed subjects minor side effects such as nervousness, perspiration and tachycardia have been mentioned. Q HGH was injected in considerably larger than physiological doses and under these circumstances many of the responses which are usually observed in the fed state did not occur. Instead,
612
DRENICK,
GOLD
AND ELRICK
they tended to progress in the opposite direction. Protein catabolism was increased and mineral excretion was enhanced drastically rather than diminished. The actual mineral loss far exceeded the amounts released from metabolized lean tissue. Whether smaller doses of HGH might have had similar effects was not examined. The calorigenic stimulus of HGH in fasting has to be satisfied largely by an increased utilization of fat and/or by an increment in protein catabolism. Presumptive evidence for the latter is the increased nitrogen and creatinine excretion. In response to the calorigenic stimulus and the lipid mobilizing effect, FFA levels rise, the fasting ketosis increases and blood CO2 content falls. It appears that HGH accentuates the metabolic acidosis which exists with prolonged fasting. The reasons for the lack of a rise in FFA in one subject is unclear but it is possible that a transient increase may have been missed due to long intervals between specimen collections. The marked differences in nitrogen and creatinine excretion between individual subjects may be due in part to differences in adaptation to protein sparing with differing durations of the preceding fast periods. It is also possible that different subjects respond differently to either the calorigenic or lipid mobilizing effects of growth hormone. It has been shown that with the development of acidosis, a rapid mobilization of cations from various tissues, particularly from bone can be induced.15,1G Assuming that cations were mobilized by such a mechanism, they could be made available in increased quantities to balance enhanced acid excretion in the urine. Phosphate and titratable acidity are excreted in large amounts to compensate for the increasing acidosis. The failure to demonstrate increased urine ketone excretion in the presence of a rise in blood ketones is remarkable. It is possible that renal clearance for ketoacids is impaired similar to the defect of uric acid clearance. The expansion of the exchangeable sodium pool, despite marked urinary sodium losses, supports the probability of an increased mobilization of bone minerals. Changes of similar and statistically highly significant dimensions had been observed in fasting subjects when a mercurial diuretic caused a natriuresis and a simultaneous expansion of the exchangeable sodium ~001.~’ A transient redistribution of minerals and fluid appears to be a reasonable explanation for the clinical events because the effect of HGH was quite transient, subsiding after two to three days. This was the case also in the subject given HGH for five consecutive days. With continued fasting, a return to baseline serum levels and urinary excretion occurred over the same time span in this subject as was noted in the others after single injections. In one of the subjects, HGH injections were repeated three times at weekly intervals but only the first injection caused the acute changes described above. The failure of repeated injections to elicit equivalent responses suggests that, following the initial HGH administration, all readily mobilizable ions had entered the exchangeable pool and been disposed of. That a relatively mild systemic acidosis and a moderate mineral loss should be associated with severe clinical ill effects is unusual. The explanation may be that after prolonged fasting a somewhat labile biologic and physiologic
ACUTE
SYMPTOMATIC
613
KETOACIDOSIS
milieu exists. A systemic acidosis had been present and a sizeable mineral and water loss had occurred during the initial fast period. This precarious equilibrium appears to be easily disturbed and the sequelae seem disproportionate. REFERENCES 1. Ashley, B. C., and Whyte, H. M.: Metabolic studies in starvation. Aust. Ann. Med. 10:92, 1961. 2. Beck, P., Koumans, J. H. T., Winterling, C. A., Stein, M. F., Daughaday, W. H., and Kipnis, D. M.: Studies of insulin and growth hormone secretion in human obesity. J. Lab. Clin. Med. 64:654, 1964. 3. Schwarz, F., van Riet, H. G., and Schopman, W.: Serum growth hormone and energy supply in fasting obese patients. Metabolism 15: 194, 1966. 4. Ruedi, B., Aubert, M., Felber, J. P., and Vannotti A. : Etude des taux plasmatiques d’hormone de croissance chez l’obese. Schweiz Med. Wschr. 98:709, 1968. 5. Elrick, H., Yearwood-Drayton, V., Arai, Y., Leaver, F., and Morris, H. G.: Collection, processing and fractionation of human pituitary glands. J. Clin. Endocr. 23: 694, 1963. 6. Drenick, E. J., Hunt, I. F., and Swendseid, M. E.: Magnesium depletion during prolonged fasting of obese males. J. Clin. Endocr. 29:1341, 1969. 7. Edelman, I. S.: Body water and electrolytes. In Brozek, J., and Henschel, A., (Ed.): Techniques for Measuring Body Composition. Proceedings of a Conference. Washington, D.C., National Academy of Sciences, 1961, pp. 140-154. 8. Beck, J. C., McGarry, E. E., Dyrenfurth, I., and Venning, E. H.: Metabolic effects of human and monkey growth hor-
mone in man. Science 125:884, 1957. 9. Ikkos, D., Luft, R., and Gemzell, C. A.: Effect of human growth hormone in man. Lancet 1:720, 1958. 10. Henneman, P. J., Forbes, A. P., Moldawer, M., Dempsey, E. F., and Carroll, E. L.: Effects of human growth hormone in man. J. Clin. Invest. 39:1223, 1960. 11. Raben, M. S., and Hollenberg, C. H. Effect of growth hormone on plasma fatty acids. J. Clin. Invest. 38:484, 1959. 12. Mautalen, C., and Smith, R. W., Jr.: Lipolytic effects of human growth hormone in resistant obesity. J. Clin. Endocr. 24:494, 1965. 13. Bray, G. A.: Calorigenic effect of human growth hormone in obesity. J. Clin. Endocr. 29: 119, 1969. 14. Henneman, D. H., Dull, T. A., Maurice, P. F., and Hennemann, P. H.: Effect of feeding vs fasting on metabolic changes produced by human growth hormone in man. J. Clin. Endocr. 25:592, 1962. 15. Stinebaugh, B. I., and Schloeder, F. X.: Studies on the natriuresis of fasting. I. Effect of prefast intake. Metabolism 15:828, 1966. 16. Reidenberg, M. M., Haag, B. L., Channick, B. J., Schuman, C. E., and Wilson, T. G. G. The response of bone to metabolic acidosis in man. Metabolism 15:236, 1966. 17. Drenick, E. J., Gold, E. M., and Blahd, W. H.: Evidence for rapid mobilization of sodium from “non-exchangeable” sodium pool. Clin. Res. 14: 183, 1966.
able Na pool suggested mobilization of Na from storage sites, presumably bone. It appears that the precarious clinical adjustment peculiar to prolonged fasting is disturbed by the increasing ketosis resulting from the calorigenic stimulus and lipolytic effect of HGH. Mineral losses and the mobilization of sodium are a sequel to the accentuation of the acidosis and the clinical symptoms result from the redistribution of water and electrolytes among body compartments in marginally depleted subjects. (Metabolism 19: No. 8, August, 60&613, 1970)
OBESE SUBJECTS metabolize sizable quantities of body protein in addition to fat. Although the daily protein loss diminishes with prolonged fasting, anabolic agents have been administered in an attempt to further reduce protein catabo1ism.l Because endogenous growth hormone falls to very low levels during extended fasts,“-4 exogenous HGH may have anabolic activity and, additionally, promote lipolysis. When HGH was administered to obese subjects in pharmacologic doses during prolonged fasts, several unexpected effects were observed. The untoward clinical manifestations, the changes in serum chemistry and the striking alterations in renal excretion of various ions are presented and discussed.
F
ASTING
MATERIALS AND METHODS Four obese but otherwise healthy males were studied. They weighed from 126 to 164 Kg. on admission to a metabolic ward. Their ages ranged from 39 to 51 years. During the fast, tap water was allowed ad lib. One multivitamin tablet, 2 Cm. of Probenecid and 2 Cm. of potassium chloride were administered daily. Except for a constant rate of weight loss and a mild degree of postural hypotension, the subjects were clinically stable and well. All were ketotic and manifested a mild metabolic acidosis. Fasting periods had lasted from 26 to 52 days when 12-18 mg. of HGH was administered by intramuscular injection. Three subjects received a single dose and one was given 18 mg. injections daily for five days. From the Veterans Administratiotl Center, Los Angeles, Calif. Received for publication March 20, 1970. Supported in part by an NIH grant. ERNEST J. DRENICK, M.D.: Veterans Administration Cenfer, Los Angeles, Calif.: Associate Professor, UCLA Medical School, Los Angeles, Catif. ERNEST M. GOLD, M.D.: Veterans Administration Center. Los Angeles, Calif.: Assistant Professor, UCLA Medical School, Los Angeles, Calif. HAROLD ELRICK, M.D.: Director, Metabolic Clinic, Mercy HOSpital, Sun Diego, Calif. 608
METABOLISM,
VOL. 19, No. 8 (AUGUST),
1970
ACUTE SYMPTOMATICKETOACIDOSIS
609
The HGH administered in this study was prepared by the method of Elrick et al.5 One milligram of the hormone approximated 1 USP unit by bioassay. The lyophilized hormone was dissolved in 0.5 ml. of 0.1 N NaOH and diluted to 1.0 ml. with sterile saline on the morning of the injection. In three subjects a biologically inactive preparation was injected which failed to evoke any responses. An active preparation was given in a second trial to one of these three subjects with the anticipated results. Serum was analyzed daily or at suitable intervals before and following HGH. Glucose, free fatty acids, creatinine, uric acid, electrolytes and total ketoacids were measured. Urine was collected in 24-hour pools before and following the injection. Sodium, potassium, calcium, phosphorus, titratable acidity, ketones, nitrogen and creatinine were measured quantitatively. The methods have been described previously. 6 In two subjects, exchangeable sodium was measured by isotope dilution utilizing the method described by Edelman7 on the day before and 24 hours after the injection of HGH. 22Na was used as a tracer. Under comparable experimental conditions, this method has given reliable and reproducible results with p values of < .OOl. Because of clinical complications and because concomitant analyses exhausted the supply of various specimens, not all of the measurements cited were carried out in each subject on each day of observation.
RESULTS Clinical Course
All four subjects developed weakness, dizzyness, muscle cramps and a marked accentuation of a pre-existing postural hypotension within 8 to 24 hours after HGH. All four subjects became nauseated and vomited. Syncope occurred in one patient. From the second day on, symptoms gradually improved and subsided after the third day, despite continuation of the fast. This was also true for the one subject in whom HGH was continued for five days. Weight loss was accelerated beyond the expected rate of 1 pound/day to a maximum loss of 15 pounds in three days as a result of a greatly increased urine output. Serum
Moderately elevated FFA concentrations in the serum rose further in two of three subjects and ketoacids increased in two of two subjects following the HGH injections. COZ which was lowered before HGH manifested a significant decline in two subjects. One subject (K) who manifested no change in FFA failed to develop a convincing fall in bicarbonate concentration (Fig. 1). The changes were transient and a spontaneous return to original levels occurred within three to five days. Blood glucose, serum creatinine, cholesterol and uric acid levels remained unchanged. The serum concentration of sodium, potassium, calcium, phosphorus and magnesium remained normal and unaltered. Urine
Urinary eIectrolyte excretion underwent marked but transient changes following HGH (Fig. 2). Sodium conservation during fasting is generally very efficient and after the first two weeks only minute quantities ( < 3-5 mEq./day) are excreted unless sodium supplements are furnished. HGH provoked a prompt natriuresis in all subjects. The loss was marked on the day of administration of HGH and maximal on the following day. Potassium losses followed a
610
DRENICK,
GOLD AND ELRICK
Fig. l.-Changes in serum levels following HGH are indicative of increased lipolysis and ketoacidosis. Each curve represents changes for one subject. (Individual subjects are identified by their initials.)
0
, -1
24,HR
1 I
URINE
,
’
DA&
ELECTROLYTES
K (mEq)
DAYS
3
4
ACUTE
SYMPTOMATIC
611
KETOACIDOSIS
24 H&URINARY
EXCRETION
Fig. 3.-Increased urinary nitrogen following HGH suggests enhanced protein catabolism. NITROGEN (pm)
-I
!
I
I
2 DAYS
3
4
similar pattern. Calcium and magnesium excretion rose to a lesser degree. Urinary phosphorus increased markedly. Figure 3 shows that urinary nitrogen losses in three of four subjects increased to nearly twice the pre-HGH levels. Commensurate increments in creatinine excretion were noted. Changes in the pattern of urinary ketone excretion, determined in only two subjects, were inconsistent and, in the same subjects, titratable acidity increased substantially on the day of the HGH injection. Exchangeable
Sodium
Within eight hours after HGH, exchangeable sodium rose from 3222 to 3759 in one subject and from 3596 to 4537 mEq. in the other. This rise coincided with the appearance of various clinical ill effects. DISCUSSION
Normally the administration of HGH results in a positive nitrogen balance and in retention of potassium, sodium and phosphorus. The calcium balance may become positive, though usually urinary calcium excretion rises.8-10 HGH causes a rise in serum FFA levels .3J1J2 A calorigenic effect in the lean and in the obese had been described.1°J3 In short fasts (48 hours) HGH administration enhanced the fasting ketosis and produced an exaggerated rise in serum FFA.14 No adverse clinical sequelae were described under these circumstances, but in normal, fed subjects minor side effects such as nervousness, perspiration and tachycardia have been mentioned. Q HGH was injected in considerably larger than physiological doses and under these circumstances many of the responses which are usually observed in the fed state did not occur. Instead,
612
DRENICK,
GOLD
AND ELRICK
they tended to progress in the opposite direction. Protein catabolism was increased and mineral excretion was enhanced drastically rather than diminished. The actual mineral loss far exceeded the amounts released from metabolized lean tissue. Whether smaller doses of HGH might have had similar effects was not examined. The calorigenic stimulus of HGH in fasting has to be satisfied largely by an increased utilization of fat and/or by an increment in protein catabolism. Presumptive evidence for the latter is the increased nitrogen and creatinine excretion. In response to the calorigenic stimulus and the lipid mobilizing effect, FFA levels rise, the fasting ketosis increases and blood CO2 content falls. It appears that HGH accentuates the metabolic acidosis which exists with prolonged fasting. The reasons for the lack of a rise in FFA in one subject is unclear but it is possible that a transient increase may have been missed due to long intervals between specimen collections. The marked differences in nitrogen and creatinine excretion between individual subjects may be due in part to differences in adaptation to protein sparing with differing durations of the preceding fast periods. It is also possible that different subjects respond differently to either the calorigenic or lipid mobilizing effects of growth hormone. It has been shown that with the development of acidosis, a rapid mobilization of cations from various tissues, particularly from bone can be induced.15,1G Assuming that cations were mobilized by such a mechanism, they could be made available in increased quantities to balance enhanced acid excretion in the urine. Phosphate and titratable acidity are excreted in large amounts to compensate for the increasing acidosis. The failure to demonstrate increased urine ketone excretion in the presence of a rise in blood ketones is remarkable. It is possible that renal clearance for ketoacids is impaired similar to the defect of uric acid clearance. The expansion of the exchangeable sodium pool, despite marked urinary sodium losses, supports the probability of an increased mobilization of bone minerals. Changes of similar and statistically highly significant dimensions had been observed in fasting subjects when a mercurial diuretic caused a natriuresis and a simultaneous expansion of the exchangeable sodium ~001.~’ A transient redistribution of minerals and fluid appears to be a reasonable explanation for the clinical events because the effect of HGH was quite transient, subsiding after two to three days. This was the case also in the subject given HGH for five consecutive days. With continued fasting, a return to baseline serum levels and urinary excretion occurred over the same time span in this subject as was noted in the others after single injections. In one of the subjects, HGH injections were repeated three times at weekly intervals but only the first injection caused the acute changes described above. The failure of repeated injections to elicit equivalent responses suggests that, following the initial HGH administration, all readily mobilizable ions had entered the exchangeable pool and been disposed of. That a relatively mild systemic acidosis and a moderate mineral loss should be associated with severe clinical ill effects is unusual. The explanation may be that after prolonged fasting a somewhat labile biologic and physiologic
ACUTE
SYMPTOMATIC
613
KETOACIDOSIS
milieu exists. A systemic acidosis had been present and a sizeable mineral and water loss had occurred during the initial fast period. This precarious equilibrium appears to be easily disturbed and the sequelae seem disproportionate. REFERENCES 1. Ashley, B. C., and Whyte, H. M.: Metabolic studies in starvation. Aust. Ann. Med. 10:92, 1961. 2. Beck, P., Koumans, J. H. T., Winterling, C. A., Stein, M. F., Daughaday, W. H., and Kipnis, D. M.: Studies of insulin and growth hormone secretion in human obesity. J. Lab. Clin. Med. 64:654, 1964. 3. Schwarz, F., van Riet, H. G., and Schopman, W.: Serum growth hormone and energy supply in fasting obese patients. Metabolism 15: 194, 1966. 4. Ruedi, B., Aubert, M., Felber, J. P., and Vannotti A. : Etude des taux plasmatiques d’hormone de croissance chez l’obese. Schweiz Med. Wschr. 98:709, 1968. 5. Elrick, H., Yearwood-Drayton, V., Arai, Y., Leaver, F., and Morris, H. G.: Collection, processing and fractionation of human pituitary glands. J. Clin. Endocr. 23: 694, 1963. 6. Drenick, E. J., Hunt, I. F., and Swendseid, M. E.: Magnesium depletion during prolonged fasting of obese males. J. Clin. Endocr. 29:1341, 1969. 7. Edelman, I. S.: Body water and electrolytes. In Brozek, J., and Henschel, A., (Ed.): Techniques for Measuring Body Composition. Proceedings of a Conference. Washington, D.C., National Academy of Sciences, 1961, pp. 140-154. 8. Beck, J. C., McGarry, E. E., Dyrenfurth, I., and Venning, E. H.: Metabolic effects of human and monkey growth hor-
mone in man. Science 125:884, 1957. 9. Ikkos, D., Luft, R., and Gemzell, C. A.: Effect of human growth hormone in man. Lancet 1:720, 1958. 10. Henneman, P. J., Forbes, A. P., Moldawer, M., Dempsey, E. F., and Carroll, E. L.: Effects of human growth hormone in man. J. Clin. Invest. 39:1223, 1960. 11. Raben, M. S., and Hollenberg, C. H. Effect of growth hormone on plasma fatty acids. J. Clin. Invest. 38:484, 1959. 12. Mautalen, C., and Smith, R. W., Jr.: Lipolytic effects of human growth hormone in resistant obesity. J. Clin. Endocr. 24:494, 1965. 13. Bray, G. A.: Calorigenic effect of human growth hormone in obesity. J. Clin. Endocr. 29: 119, 1969. 14. Henneman, D. H., Dull, T. A., Maurice, P. F., and Hennemann, P. H.: Effect of feeding vs fasting on metabolic changes produced by human growth hormone in man. J. Clin. Endocr. 25:592, 1962. 15. Stinebaugh, B. I., and Schloeder, F. X.: Studies on the natriuresis of fasting. I. Effect of prefast intake. Metabolism 15:828, 1966. 16. Reidenberg, M. M., Haag, B. L., Channick, B. J., Schuman, C. E., and Wilson, T. G. G. The response of bone to metabolic acidosis in man. Metabolism 15:236, 1966. 17. Drenick, E. J., Gold, E. M., and Blahd, W. H.: Evidence for rapid mobilization of sodium from “non-exchangeable” sodium pool. Clin. Res. 14: 183, 1966.