Different Potencies of Biosynthetic Human and Purified Porcine Insulin

 

Fasting Fasti ng and Skeleta Skeletall Muscle Muscle Enzymes in Obese Obese Men Short-term rm fasting fasting in the treatm ent of o besity. Rath,  R., K.  Vondra:  Rath,  Vondra:  Short-te Nahrung  2 1  : 193-197 (1977) Rath, R., Z. Slabochova,  K.   Vondra:  Vondra:  Immunoreactive insulin in obesity obes ity of adult women. Int em at J. of Obe Obesi sity ty 1: 2 79- 286 (1977) Vondra, K., R. Rath:  Obesity and thyroid function. 1. Values of the Achilles tendon reflex. Endokrinologie 62: 310-320 (1973)  Improved needle for muscle Vondra,  K., R. Rath, Z. Kroupa:  Kroupa: Improved biopsy. Klin. Wschr. 52: 747-748 (1974) Vondra, K., R. Rath, A. Bass: Activity of some enzymes of energy metabolism in striated muscle of obese subjects with respect to body composi compositio tion. n. Horm. Metab. Metab. Re Res. s. 7: 475 -48 0 (1975)

Horm. metabol. Res. 15 (1983)

27 1

effect Vondra,  K., R. Rath:  Obesity and thyro id function. 2. The effect of prolonged caloric restriction on Achilles tendon reflex values. Endokrinol Endokr inologi ogiee 66 : 332 -33 6 (1975) Vondra, K., R. Rath, A. Bass: Skeletal muscle HK activity and fasti fasting ng F FA blood leve levell in man. Horm . Metab. Res. 8: 323 (1976)   Effect of Vondra,  K., R. Rath, A. Bass, L. Kukla, Z. Slabochova:  Slabochova:  protracted intermitten t fast fasting ing on the activitie activitiess of enzymes involved in energy metabolism, and on the concentration of glycogen, protein a DNA in skeletal muscle of obese women. Nutr. Metab. 20: 329-337 (1976) Vondra, K., A. Bass, V .  Brodan, E. Kuhn, M.  Andel, A. Veselkova,  Vitek:  Activities  Activiti es of m energ y supplying enzymes after 5V.days complete fasting in uscle youngenergy men. Physiol. Bohemoslov. (1982)31:311-314(1982)

Requests for for reprints should be addresse addressedd to : MUDr. K. Vondra, CS c, Department of Medici Medicine ne I of the Institute for Clin Clinica icall and Exp erimental Medicine, Videnska 80 0, 146 22 Prague 4 (Czechoslovakia)

Horm. Hor m. metabol. Res Res.. 15 (1983) 27 1-2 74 ©G eorg Thieme Verl Verlag ag Stuttgart • New York

Different Potencies of Biosynthetic Human and Purified Porcine Insulin K.J. Schliiter, Schliiter, F. Enzm ann* and L. Kerp Z e n t r u m f i i r I n n e r e M e d i z i n , A b t e i l u n g f i i r K l i n i s c h e E n d o k r i n o l o g i e , U n i v e r s i ta ta t F r e i b u r g , a n d *Eli Lilly, Bad Homburg, Germany

Su m m ar y T he gluc os e c lam p t ec hnique w as us used ed t o c ompa re t he bio logic al ac t iv it y of purif ied porc ine ins ulin and Bios y nt het ic H uman I ns ulin (BH I ). An int rav enous bolus of 0. 1 U / k g BW w as injec t ed in eight male v olunt e ers , and t he gluc os e w as c lamped at bas eline v alues (eugly c emic c lamp). Serum ins ulin, s erum   C-peptide  and plas ma gluc os e did no t dif f e r bet w een porc ine and huma n ins ulin . T he ins ulin ind u c e d gl gl u co co s e c o n s u m p t i o n d i f f e r e d s i g n i f i c a n t l y ( p <   0.007) bet w een purif ied porc ine ins ulin (50. 5 ± 5. 2 [ SEM] g/ 2h) and B i o s y n t h e t i c H u m a n I n s u l iin n (63.5 ± 4.5 g/2 h). Purified porc ine I ns ulin induc ed a horm ona l rres es pons pons e w i t h s ignif ic a nt ly ( p < 0 . 0 5 ) e lle e v a t e d c o n c e n t r a t i o n s o f s e ru ru m g r o w t h h o r m o n e (12. 1 ± 0. 25 ng/ ml) and s erum C ort is ol  ol   1 6 1 . 4  4  ± 2 8 . 6 n g / m l ) , w h i c h w e r e n o t o b se se r v e ed d following Biosynthetic Human I ns ulin (s erum gro w t h horm one : 2. 6 ± 0. 2 ng / m l; s erum Co r ti so l :  117. 3 ± 14. 8 ng / m l). T he dat a c o nf ir m earlier res ult s indic at ing hormonal and met abolic dif f erenc es bet w een human and porcine insu lin. K ey-W o r d s:  s:  Biosynthetic Human Insulin — Glucose Clamp Technique  Technique   — Glucose Requirement  Growth Hormone   Cortisol

Introduction The biological activity of insulin has been assessed by intravenous bolus injection, continuous con tinuous infusion, and applica applica-tion of a of  a si  singl nglee subcutaneous subcutane ous  dose.  Studies show that intravenous intrave nous bolus inj injecti ection on produce counterregulatory counterregulatory hormonal response responsess which modify the m etabolism etabolism of

glucose. Sinc Since e dif differ ference encessnin the been hormonal responses responses to that human and porcine insulin insuli  have been  have reported, namely human insulin insulin produced a produced  a lower  lower output of  growth hormone,  growth  hormone, Cortisol, and Cortisol,   SchViter, Petersen, Borsche,  and epinephrine Hobitz  and and Kerp 1981;  SchViter, Petersen and Kerp  1982), it is difficult difficult to compare comp are the effects on glucose glucose metabolism metabolism.. With the glucose clamp technique, essentially normal fasting plasma glucose plasma  glucose concentrations  concentrations can be maintained   Pfeiffer, Thum  and  Clemens  1974;  Clemens   DeFronzo, Tobin  DeFronzo,  Tobin and Andres  Andres 1979;Nosa and Alberti  Alberti 1981).  1981).  Hormonal ;Nosadini dini,, Noy , Ku rtz  and responses resp onses are minimal minimal under these experimental conditions. The effect effect of Biosynthetic Human Insulin Insulin (BHI) and puripu rified porcine insulin (PPI) on glucose metabolism  were  were meas measured usin usingg the euglycemi euglycemicc clamp technique to avo avoid id interference of other hormones. Subjects and Subjects  and Methods

Received:   15 Received: 15 March  March   1982

Accepted: 25 Aug 1982

Informed consent was obtained from 8 male volunteers (age: 24.2 ±1.3 years [mean [mean ± SEM], body weight: 75.1 ± 1. 1.33 k g; height: 185.6 ±3.9 cm) without fami family ly or personal hist history ory of diabetes. Laboratory

 

27 2

Horm.

metabol. Res. 15 (1983)

K.J. Schliite Schliiter, r, F. Enzmann and L. Kerp

chemistry, ECG, physical examination and oral glucose tolerance tests (100 g) were normal. In  a   randomized study, each subject received both Biosynthetic Human Insulin (BHI) (Eli (Eli Lilly, Lilly, Indianapoli Indianapolis, s, CT 49 69 -1B ) and identical formulated purified pork insulin (PPI) (Eli Lilly, Indiana CT 4970-OA) intravenously (bolus: 0.1 U/kg BW).  The compolis, CT polis,   BW). pound  of  in  in  this experiment was identical identica to l  the  the BHI (Lot  B  BHI HI used 615-70N-174-9) used in  the  USP-rabbit hypoglycemia assay. The biologica biol ogicall activit activityy in rabbits was 27.5 ±1 .7 units/mg, which was 160 nmoles/mg  for  BHI and 159 nmoles/mg for  PPI.  for The tests were performed   at  one week intervals  in  this study. One hour before the administration  of  insulin, three catheters were in inserted into antecubital veins. The glucose-controlled insulin infusion system (Biostator, Life Science Instruments, Miinchen, FRG) was calibrated for  continuous blood glucose monitoring and glucose in infusion. The plasma glucose concentration was clamped  at  individual fasting fasti ng baseli baseline ne levels ((± ± 0.25 mMol/1). The Biostator was programmed  to   maintain the individual (76—96 mg/dl) euglycemia of  maintain the subjects. Glucose (40 g/100 ml) was infused through the three channels (saline-, glucose-, and optional channel)  of  the Biostator. The maximum glucose infusion   by  the Biostator  the Biostator was 2.4 g/min. Afterr an hour's rest, a bolus of Afte  insulin (0.1 U/kg  BW BW) was injected intravenously. Venous blood samples were obtained   a t - 1 5  , 0, 10, 105 and 15 15,,  20, 25, 30, 35, 40, 45, 50, 55, 60, 75, 90, 105 120 minutes. Plasma glucose was determined by the glucose oxidase technique with a Beckmann glucose glucose analyz analyzer er (Beckmann Instrum ents, Inc., F ullerton, Calif.). The following radioimmunoassays were carried out: serum insulin (Phadebas-Insulintest, Pharmacia-Diagnostics,  A B, Uppsala, Sweden) (the  PPI and from and BHI with themlantibody used used in, this RIA cross-reaction was identical  of in the range 10 MU/ MU/ml to 320 MU/ml) MU/ml), serum serum C-peptide (Riamat, C-peptide assay, Byk-Mallinckrodt, Diezenbach, FRG), serum Cortisol (Cortisol-Ria, Travenol, Cambridge, Mass.), and serum growth hormone (Serono, Freiburg, FRG). Interassay variations were reduced  by    using using the same immunoassay for all samples  of  an individual subject. Intra-assay error, measured as coefficient coefficient of variation, was below  5 in all cases cases..

Fig.  1  Pl Plasma asma gluc glucose ose (m g/m l), serum insulin (M U/m l), serum   U/kg BW, given  at 0  at C-peptide (ng/ml) after an  i.v. bolus (0.1 • )  and purified minutes) o f  Biosynthetic Human Insulin  • pork insulin insulin (o — o) during e eugl uglycemi ycemicc cla clamp mp  in  eight male volunteers. The values  at each time interval represent th e  mean   of of ± SEM  of eight samples. There was no statistica l significance differences between  th e p  porcine orcine and human grou p.

The data are expressed as mean  ± SEM. Areas under the concentration-time curves were calculated according  to  the equation:  the *f

x

x

v

 +

( n + l - n >  (n+l   ny)

Wilcoxons test  for  paired differences differences was used. Results

Eight male volunteers received received either Bios ynthetic Human Insulin (BHI) (0.1 U/kg BW) or purified porcine insulin (PPI) during an euglycemic clamp stu dy. Plasma glucose, serum insulin, serum C-peptide, serum growth hormone, and serum Corti Cortisol sol concentrations ob tained from the venous blood samples samples are shown in Fig. 1 and Fig. 2. The individual fasting plasma glucose values (BHI:   89.1 ± 1.6 mg/dl;PPI: 90.1 ± 2.7 mg/dl) were maintained throughout the clamping procedure, but those following Biosynthetic Human Insulin were slightly lower than those following purified porcine insulin. Throughout the experiment the maximum blood glucose fluctuation was 20 mg/dl and the coefficient coefficient of variation of the plasma glucos glucose e values was below 15 . Serum insulin insulin concentra tions did not differ differ during the test period. Following the intravenous administration identical peak values (BHI: 309 .3 ± 61.0 juU/ml juU/ml;; PPI:   335.2 ± 64.2 /xU/ml) of insulin were obtained.

Fig.  2  Serum grow th hormone and ser serum um Cortisol Cortisol after an  i.v.  i.v.  at 0 minutes)  o f  Biosynthetic Human bolus (0.1  U/kg BW, given at • )  and purified Insulin   • purified porcine porcine insul insulin in (o — o) during euglycemicc clamp  in eight male volunteers. The values at euglycemi  at ea  each ch tim e  ± SEM  of eight samples. interval represent  th e mean ± at X, values that differ significantly from   the human insulin group  at by  paired Wilcoxon's test). that time interval  p<   0.05  by

 

Horm. metabol. Res. 15  (1983)  

Potencies  of  Biosynthetic Human and Purified Porcine Insulin

273

Serum  C-peptide  levels following Biosynthetic Human Insulin and purified porcine insulin did not differ differ sig signif nifii A suppression cantly. A cantly.  suppression  o endogenous  of f insulin secretion by exogenous insulin w insulin  was as no  no t observed observed (Fig.  1).  1)  A . significant (p< 0.05) elevation  o  serum  se  of f rum growth hormone concentration (from 2.8 ±  1  1.. ng/ml   7 ng/ml  at  0 minutes  to  12.1  ± 6.2  ± 6.2 ng/ml at 30 minutes) occurred after after the adm inist inistration ration of purifi fied ed porcine insulin. BHI did did nnot ot produce any fluctuat fluctuation ion of serum growth hormone (2.5 ±  1  1.. ng/ml   9 ng/ml  at  0 minute minutess

Chiasson, Keller Chiasson,  Keller an  and d Rubenstein  Rubenstein    1978;  Beischer, Schmid, Kerner, Keller an  and d Pfeiffer 1978) may  be  be due  to  to  this tech-

 at and 2.5 ± 2.5  ± 2.0  2.0 ng/ml  30 m inutes). inutes). Serum Corti Cortisol sol levels levels were also elevated elevated   A serum Cortisol 38.8 ± 38.8  ± 8.1  8.1 ng/ml) after after purified porcine insulin but not after human insulin  insulin   A serum Cortisol  23.1 ± 4.5 ± 4.5 ng/ml) (p<0.05).

 at  levels.  levels. clamped  individual glucose  The secret ion of growth hormone andfasting  of  o  Cortisol appears  Cortisol f  appears to be a response  asecretion  response to the heterologous insulin. insulin.

nical difference. A small but significant rise  i  in    serum n serum growth hormone   and  and as observed serum Cortisol concentrations w concentrations  was  observed following the  the injection  of  a bolus  a bolus of purified purified porcine insulin, which which was not obse observe rvedd aft after er Biosynthetic Biosynthetic Human Insulin. This canno t be  be attributed to differences in plasma glucose or  or to plasma glucose plasma  glucose con  concentrations centrations because  plasma glucose was glucose was

Significantly more exogenous more  exogenous glucose was required was required  to  to compensate the hypoglycemic effect   of  Biosyntheticc Human  Biosyntheti Insulin in comparison comparison ttoo purified purified pork insulin insulin   + 30.6  ±  ± 7.6  glucose re  glucose The amount of  required quired to compensate compensate the effe effect ct percent). In five insulin-dependent diabetic subjects BHI of exogenous insulin w insulin  was as    significantly (2p< 0.007)  0.007)  higher aft after er Biosynthetic Human Insulin Insulin (63.5 (63 .5 ±  ± 4.5  4.5 g/2h) than wa wass more (but not signifi significantl cantly) y) effecti effective ve than natural pork after purified porcine insulin (50.4 ±5.2 g/2h). insulin   Klier, Kerner, Torres and Pfeiffer  Pfeiffer 1981). This  difference which which i  is s  contrast  a previous   a  previous study   Massi  in  to Table 1 Table  1 shows the shows the individual individual glucos glucosee requirements over the Benedetti, Burrin,  Capaldo and Alberti Alberti 1981) with the two-hour periods  f  for or  each subject. insulin insul in infusio infusionn technique, can be explained by the the small  small in increments of endogenous Cortis Cortisol ol and growth horm one obob served served after porcine insulin. Cortisol Cortisol and growth hormone produced hyperglycemia hyperglycemia by decreas decreasing ing both hepatic and Discussion extrahepatic sensitivity to insulin   Rizza, Mandarino Rizza, Mandarino and The glucose clamp technique has been used to assess  the Gerich  1981;  Rizza, Mandarino,  Mandarino,  Westland and  Gerich  Gerich biological activity of insulin by continuous infusion   De 1981). Fronzo, Tobin  and   Andres \919;Pfeiffer, Thum  Andres \919;Pfeiffer, Thum and On the other hand a signific significantl antlyy inhibited hepatic glu glucos cosee Clemens   1974;Nasadini, Noy, Clemens 1974;Nasadini, Noy, Kurtz and  Alberti  1981;  Alberti  has s production ha production  been observed after porcine insulin in com 1981). Massi-Benedetti, Burrin, Capaldo and Alberti  Alberti 1981).  In this parison  to    semisynthetic semisynthetic human insulin   Mutter,  Keller  and  insulin was used. study, however,  a bolus injection injection of  The   1982). Berger  Berger  The weaker suppression of hepatic glucose peak serum serum insulin insulin concentrations (about (abou t 300  300 /iU/ml  /iU/ml in production produc tion followi following ng porcine insulin, caused caused by Cortis Cortisol ol comparison compari son to values values obtained by continuous infusion infusion of and growth hormone secretion, might expla explain in the comparababout 50—100 about  50—100 ^U/ml)  ^U/ml)   Massi-Benedetti, Burrin, Capaldo ow glucose ly  low  glucose requirement following porcine insulin  in inand Alberti 19Sl;Dobeme, Schulz 19Sl;Dobeme, Schulz and Reaven 1981) per- ly l jection in comparison comparison to t o human insulin. The results indi while continuous inf  while continuous sisted  f  for or  only a short period infusi usion on cate th at homologous homologou s insulin insuli n produces eff effect ectss which are are   levels. results i results  in n prolonged elevated levels.  The fact that  we  we have different diff erent from fr om those produced by heterologous insulin insu lin  in not observed a suppression  of  endogenous insulin  endogenous  insulin secretion as judged judged by serum serum  C-peptide   Liljenquist, Horwitz, Jennings, man.

Table 1  1   Glucose   0.1 U/kg Glucose requirement (g/2h) after a bolus injection BW)  of  Biosynthetic Human Insulin  BHI) and purified p ork insulin (PPI)) during euglycemic c lamp . (PPI

Acknowledgements The authors gratefully acknowledge  the  skilled  skill ed tec hnical assis assistance tance of Mrs. Heike Vorwerck and thank  Prof.  Dr. John A. Galloway Galloway (University of  Indianapolis)  his comments  m anuscript. anuscript.  for  on the

glucose requirement g/2h Subject   No.

BHI 

 p<   0.007. *Significance  o f mean differences,

PP

References Beischer,  W . M.   Schmid, W.   Kerner, L. Keller, E.F. Pfeiffer: Does insulin play a role  in the  regulation  its own secretion? secretion? H orm.  of  of Metab.. Res. Metab Res. 10: 168-1 69 (1978)  Glucosee clamp clamp tech nique: De Fronzo, R.A., J.D.  Tobin, R. Andres: Glucos a method  for  quantifying insulin secretion and  resistance.  and  Am. J. P hysiol hysiol..  237  (3): E214 -E223 (1979) (1979) Doberne, L., M.S. Greenfield, B. Schulz, M. Reaven: Enhanced glucose utilization during prolonged glucose clamp studies. Diabetes Diabe tes 30: 829 -83 5 (1981)  the Klier,  M ., W .  Kerner, A.A. Torres, E.F. Pfeiffer: Comparison  of  of biologic activity  of  Biosyntheticc Hum an Insulin  Biosyntheti Insulin and natural pork insulin  in juvenile-onset d iabetic subjects subjects assess assessed ed  by the  by glucose controlled insulin infusion system. Diabetes Care  4: 193-19 5 (1981)

 

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metabol. Res. 15 (1983)

Liljenquist, J.E., D.L. Horwitz, A.S.   Jennings,  J.-L. Chiasson, U .   Keller, A.H. Rubenstein: Inhibition of insulin secretion by exogenous insulin insulin in normal man as demonstrated by C-peptide C-peptide assay. assay. Diab Diabete etess 27: 5 63 -57 0 (1978) Massi-Benedetti,  M ., J.M. Burrin, B. Capaldo, K.GM.M. Alberti: A comparative comparative study of the activity of biosynthetic human insulin and pork insulin using the glucose clamp technique in normal subjects. Diabetes Care 4:163-167 (1981) Miiller,  R. ,  U .   Keller, W .  Berger:  Comparison of semisynthetic and porcine insulin insulin in man. J. C lin. Invest. Invest. 1 2: 281 (1982) Nosadini, R .,  G. Noy, A.B. Kurtz,  K.G.M.M. Alberti:  Differential

response to infusions highly purified and conventional bovine and porcine insulins. of Diabetes 30: 650-655 (1981) Pfeiffer, E.F., C E.F.,  C h. Thum, artificial beta cell - a h. Thum, A.H.  Clemens:  Clemens:  The artificial continuous control of blood sugar by external regulation of insulin infusion (glucose controlled insulin infusion system). Horm. Metab. Metab. Res. Res. 487: 339 -34 2 (1974)

Rizza, R., L.  Mandarino, J. Gerich: Dose-response characteristics for the effects of insulin on production and utilization of glucos glucosee in man. Am. J. Physi Physiol. ol. 240: 630- 63 9 (1981) Rizza, R., L. Mandarino, R .  Westland, J . Gerich:  Growth hormone induced insulin resistance in man: Postreceptor impairment in hepatic and peripheral tissue sensitivity to insulin. Diabetes 30: 38(1981) Schliiter, K .J., K.-G. Petersen, A.  Borsche, H. H obitz, L. Kerp:  Effects of fully synthetic human insulin in comparison to porcine insulin in normal subjec subjects ts.. Horm. Metab. Res. 13: 65 7-6 59 (1981) Schliiter,   K.J., K.-G. Petersen, A., L. Kerp: Unterschiedliche Wir-

kung von H umanundSchliiter, Schweinei Schweineinsuli In: Neue Freiburger Insuline, eds. Petersen, K.-G., K.J. L. nsulin. Kerp.n. Freiburg, Graphische Betriebe, 86-92 (1982)

Requests for reprints should be addressed to : K.J. Schliiter, M.D., Zentrum fur Innere M edizin, edizin, Universit Universitat at Freiburg, H ugstette ugstetterr S tr. 55 , D-7800 Freiburg (Germany)

Horm. Hor m. metabol. Res. 15 (1983) (1983) 274 -27 8 ©G eorg Thieme Thieme Verlag Verlag Stuttgart • New York York

Clinical Factors Influencing the Absorption of   1 2 5 I-NPH Insulin in Diabetic Patients 1

2

1

K. Kdlendorf , J .  Bojsen   and T. Deckert 1

Steno Memorial Hos pital, Gentofte, and T h e F i n se se n L a b o r a t o r y , T h e F i n s e en n Institute , Copenhagen, Denmark

Su m m ar y C linic al f ac t ors w hic h might inf luenc e t he abs orpt ion of s ubc ut aneous ly injec t ed   12 5I -N PH ins ulin w ere s t udied in 101 diabet ic s . T he dis appearanc e c urv e w as monoex ponent ial af t er a delay perio d of   1.5±0.8  h ( m ea ea n ± S D ) . L i p o h y p e r t rophy s ignif ic ant ly prolonged ins ulin abs orpt ion (half lif e ( T 1 / 2 ) = 11. 2±3. 1 h, p =   0.0001 >. Lo w bica rbo nate levels inc reas ed t he abs orpt ion (T 1 / 2   3.9±2.3  h , p < 0 . 0 5 ) . L e a n diabet ic s had a f as t er abs o rpt ion (6. 2 ± 1. 1.9 9 h) t han norm al w eigh t diabet ic s (7 . 5 ± 2. 0 h, p< 0. 0 2). Sex , age, diabet es d u r a t i o n a n d i n j e c t i o n d e p t h d i d n o t i n f l u e n c e T 1 / 2 . T he half lif e w as s ignif ic a nt ly inv ers ely c orrelat ed t o t he res t ing s u b c u ta ta n e o u s b l o o d f l o w ( r = - 0 . 8 8 2 , p < 0 . 0 1 ) . T h e o v e r a l l interindividual coe fficient of variation for insulin absorption in non k et ot ic diabet ic s w as 27. 4 . Als o c ons iderable int ra pat ie nt day -t o-day v ariat ion w as f ou nd (2 4. 5 ), and bet w een dif f e ren t injec t ion s itit es (30. 2 ). T hes e v ariat ions emphas iz e t he draw bac k s of c onv ent ional ins ulin t herapy in t he management of ins ulin-requiring diabet ic s . K ey-Wo r d s:  s:  Insulin Absorption   NPH Insulin   Diabetes Mellitus   Lipohypertrophy Lipohypertrophy    — Ketosis  Body Weight   Sex — Ag e   Diabetes: Duration   Subcutaneous Blood Flow   125 l NP H Insul Insulin in

Received: Receiv ed: IS Marc Marchh 1982

Accepted: 31 July 1982

Introduction  studies have have shown great inter- and intrasubject Earlier studies Earlier variations for absorption of intermediate-acting insulins  1969; Binder 1969; Binder  Galloway, Spradlin, Nelson,  Wentworth, Davidson and Swamer  Swamer 1981;  Faber and  and Binder  Lauritzen, Faber  Lauritzen, 1979).  However, only the influence of ag  age and diabetes PH insulin absorption have been systematicalduration on N on  NP ly studied   Dobson, Robbins, Johnson, Mdalel, Odem, Cornwall an  and d Davis 1967). The aim of  this study  this  study was to asses assesss some clinical factors which might influence the absorption of  I25I-NPH insulin from from the subcutaneous tissue tissue in diabetic patients by using the biotelemetric technique. The absorption of insulin of  insulin was measur was measured ed to determine determine the inf influe luence nce of lipohypertrophy, ketosis, body weight, sex,  age,  diabetes duration and inter- and intrapatient variation. In some diabetics, als alsoo the effect of injection injection depth and subcutaneflow (SBF)    wass evaluated. ous blood flow ( SBF)  wa Material and Methods One hundred and one diabetic patients were investigated as inpatients in 194 studies after informed consent was obtained. Group obtained.  Group  1 comprised 20 patients with insulin-dependent diabetes mellitus (IDDM) with palpable palpable lipohypertrophy at the inject injection ion site. site. Group  Group 2   included