Comparison of insulin lispro protamine suspension versus insulin glargine once daily in basal-bolus therapies with insulin lispro in type 2 diabetes patients: a prospective randomized open-label trial

AIMS

To compare the efficacy and safety of insulin lispro protamine suspension (ILPS) versus insulin glargine once daily in a basal-bolus regimen in type 2 diabetes mellitus (T2DM) patients.

METHODS

Three hundred eighty-three insulin-treated patients were randomized to either ILPS plus lispro or glargine plus lispro in this open-label 24-week European study. Insulin doses were titrated to predefined blood glucose (BG) targets. Non-inferiority of ILPS versus glargine was assessed by comparing the upper limit of the 95% confidence interval (CI) for the change of HbA1c from baseline to week 24 (adjusted for country and baseline HbA1c) with the non-inferiority margin of 0.4%. Secondary endpoints included HbA1c categories, BG profiles, insulin doses, hypoglycaemic episodes, adverse events and vital signs.

RESULTS

Non-inferiority of ILPS versus glargine in the change of HbA1c from baseline was shown: least-square mean between-treatment difference (95% CI) was 0.1% (-0.11; 0.31). Mean changes at week 24 were -1.05% (ILPS) and -1.20% (glargine). HbA1c <7.0% was achieved by 21.7 versus 29.4% of patients. Mean basal/mealtime insulin doses at week 24 were 29.6/36.2 IU/day (ILPS) versus 32.8/42.2 IU/day (glargine); the difference was not statistically significant for total dose (p = 0.7). In both groups, 56.1/25.7% versus 63.6/19.3% of patients experienced any/nocturnal hypoglycaemia (p = 0.2 for both). No relevant differences were noted in any other variables.

CONCLUSIONS

A basal-bolus regimen with ILPS once daily resulted in non-inferior glycaemic control compared to a similar regimen with glargine, without statistically significant or clinically relevant differences in hypoglycaemia. ILPS-based regimens can be considered an alternative to basal-bolus regimens with glargine for T2DM patients.

A controlled study of the influence of continuous subcutaneous insulin infusion treatment on diabetic retinopathy during pregnancy

Forty consecutive pregnant patients with insulin-dependent (Type I) diabetes mellitus were randomized at the end of the first trimester for treatment with conventional insulin therapy (CIT) or continuous subcutaneous insulin infusion therapy (CSII). Nine patients randomized into the CSII group declined the pump treatment. The mean glycosylated haemoglobin (Hb AIc) decreased (p less than 0.001) both in the CIT and the CSII groups with no difference between the groups. Some deterioration in retinopathy was found in 2/18 patients in the CIT group, in 5/13 in the CSII group, and in 3/9 of those who declined the pump treatment. The proportion of patients whose retinopathy progressed did not differ significantly between the groups, and in the majority the deterioration was mild. However, two patients in the CSII group developed acute ischaemic retinopathy, which progressed to proliferative stage in spite of laser treatment. In these two cases the decrease in the Hb AIc level was among the greatest and fastest in the study. These data suggest that a rapid near normalization of glycaemic control by CSII during pregnancy can accelerate the progress of retinopathy in poorly controlled diabetic patients.

Glucose-induced insulin secretion is potentiated by a new imidazoline compound

Sulfonylureas stimulate insulin secretion independent of the blood glucose concentration. This can lead to hypoglycaemia in type 2 diabetic patients. Over the last years a number of imidazoline derivatives have been identified that stimulate insulin secretion in a more glucose-dependent way. In agreement with this, our aim was to generate imidazoline derivatives with a potential for the treatment of type 2 diabetic patients. We developed the compound 2-[4-(4-chlorophenyl)-3-(2-methoxyethoxy)-2-naphthalenyl]-4,5-dihydro-1-H-imidazole monohydrochloride (LY389382) with an imidazoline moiety and investigated its effects on glucose-dependent insulin secretion in a beta-cell line, isolated rat islets and in vivo. We could demonstrate that LY389382 induces insulin secretion in MIN6 cells and rat islets in a glucose-dependent manner (EC50=1.1 microM and 0.3 microM, respectively). Furthermore during hyperglycaemia LY389382 increased insulin secretion in a dose-dependent manner in healthy rats, whereas the compound had no effect at euglycemia in a tenfold higher dosage. After 7 days of treatment of Zucker Diabetic Fatty [ZDF/ (Gmi/fa)] rats with LY389382 with a dose of 15 mg/kg twice daily the blood glucose concentration was reduced from 22.7 +/- 1.7 mM to 16.6 +/- 2.3 mM. During the same time period the glucose concentration increased from 21.7+/-1.7 mM to 28.9 +/- 1.3 mM in the vehicle-treated group (P<0.05). The drop of the insulin level was also inhibited by LY389382 in ZDF rats. In contrast to other well-characterised imidazolines that have been shown to induce a glucose-dependent insulin secretion only within a limited range of concentrations, LY389382 stimulates insulin secretion over a concentration range of at least two log units in a glucose-dependent manner. These data suggest that this imidazoline compound has a potential for the treatment of type 2 diabetes.

Leptin during and after preeclamptic or normal pregnancy: its relation to serum insulin and insulin sensitivity

Hyperleptinemia may be part of the insulin resistance syndrome. We studied serum leptin in preeclampsia, which is an insulin-resistant state, and sought associations between leptin and insulin or insulin sensitivity during and after pregnancy. Twenty-two proteinuric preeclamptic women and 16 normotensive controls were studied during the third trimester. Leptin was higher in preeclampsia (mean +/- SE, 34.6 +/- 3.9 v 20.0 +/- 3.3 microg/L, P = .002) and correlated directly with the level of proteinuria (r = .47, P = .03) and normal pregnancy (r = .52, P = .04), whereas insulin sensitivity as assessed by an intravenous glucose tolerance test showed no relationship to leptin. Leptin was 19.0 +/- 3.6 microg/L in 14 preeclamptic women and 10.1 +/- 2.0 microg/L (P = .11) in 11 controls 3 months after delivery. Leptin correlated directly with insulin both in preeclamptic puerperal women (r = .63, P = .02) and in controls (r = .81, P = .003). Leptin and insulin sensitivity correlated only in preeclamptic puerperal women (r = -.59, P = .02). In conclusion, (1) serum leptin is elevated in preeclampsia, (2) insulin is an important determinant of serum leptin in preeclamptic and normotensive women both during pregnancy and in the puerperium, and (3) hyperleptinemia may be part of the insulin resistance syndrome also in women with prior preeclampsia.

Aerobic endurance exercise or circuit-type resistance training for individuals with impaired glucose tolerance?

The role of physical activity in the prevention of non-insulin-dependent diabetes mellitus (NIDDM) is of utmost importance. The aim of the present study was to evaluate the metabolic effects of aerobic endurance exercise and circuit-type resistance training in subjects with impaired glucose tolerance (IGT). Twenty-two individuals participated in the study. Fourteen subjects were enrolled in the aerobic endurance exercise part of the study; seven exercised regularly for six months, while seven served as controls. Maximal aerobic capacity (VO2max) was measured and insulin sensitivity and insulin secretion were assessed by a frequently sampled intravenous glucose tolerance test (FSIVGTT). Eight subjects participated in a circuit-type resistance training program for three months. Insulin sensitivity and substrate oxidation were then assessed using the euglycemic insulin clamp technique combined with indirect calorimetry. The aerobic endurance exercise program caused in increase in VO2max (21.6 +/- 1.9 to 25.4 +/- 2.4 ml/kg.min; p < 0.05) and HDL-cholesterol (1.14 +/- 0.06 to 1.23 +/- 0.08 mmol/l; p < 0.05), but no change in insulin sensitivity nor insulin secretion occurred. However, comparing the changes between the intervention and control group, the differences disappeared. Circuit-type resistance training increased insulin sensitivity (glucose disposal) by 23% (p < 0.05), primarily due to a 27% increase in non-oxidative glucose metabolism. Both circuit-type resistance training and aerobic endurance exercise seem to have beneficial effects in subjects with impaired glucose tolerance. However, by improving insulin sensitivity, circuit-type resistance training may postpone the manifestations of NIDDM in these high-risk individuals and should therefore be included in an exercise program for IGT subjects.

Markers for the gene ob and serum leptin levels in human morbid obesity

Leptin, the product of the ob gene, reduces body fat in genetically obese animals and circulates in elevated concentrations in the blood of obese patients. Polymorphic markers situated in the proximity of the human ob gene have recently been suggested to be linked to morbid obesity. We have studied the possible association between the microsatellite markers near the ob gene and morbid obesity in 252 morbidly obese patients with a mean body mass index (BMI) of 43 +/- 7 kg/m2, and 151 lean controls with a mean BMI of 22 +/- 2 kg/m2, and searched for linkage of these gene markers to obesity in 76 affected sib-pairs (BMI > or = 32). No significant association was observed between any of the eight microsatellite markers and morbid obesity, and affected-sib-pair analysis failed to show linkage of three selected ob gene markers to obesity in the sibships. There was a strong positive correlation between serum leptin levels and BMI in morbidly obese patients; a carrier status for either of the two most prevalent alleles of the microsatellite marker D7S530 in the vicinity of the ob gene was associated with serum leptin levels in the obese subjects. Two of the markers (D7S2519, D7S649) showed a significant relation to the weight-losing response to a 16-week very-low-calorie dietary intervention. We have thus been able to confirm a tight relationship between serum leptin and body mass but have found no evidence for genetic linkage of the ob gene markers to morbid obesity in a population considered to represent a genetic isolate and to be an ideal model for studies of complex disorders.

[Diabetic nephropathy--screening, follow-up and treatment. Nephropathy Study Groups of The Finnish Diabetes Organization]

Owing to advances in the diagnosis and treatment of diabetic nephropathy, its management has become more active and is now initiated earlier after the presence of microalbuminuria has been established. In 1996 the Finnish Diabetic Association's nephropathy group issued recommendations concerning screening for diabetic nephropathy, and treatment and follow-up of patients with the disease.

The effect of (steroid) immunosuppression on skeletal muscle glycogen metabolism in patients after kidney transplantation

To examine the mechanisms by which immunosuppression by steroids impairs glycogen synthesis in human skeletal muscle, we measured glycogen synthase protein content and activity in muscle samples from 14 patients receiving corticosteroid therapy after kidney transplantation and in 20 healthy control subjects. A percutaneous muscle sample was taken before and at the end of a euglycemic hyperinsulinemic insulin clamp. Insulin-stimulated glucose disposal was reduced by 33% in kidney transplant patients compared with healthy controls (33.8 +/- 4.2 vs. 50.5 +/- 2.7 mumol (kg LBM)-1 min-1; P<0.01), primarily due to a decrease in nonoxidative glucose metabolism (14.2 +/- 3.3 vs. 32.3 +/- 2.7 mumol (kg LBM)-1 min-1; P<0.001). Glycogen synthase activity measured at both 0.1 mmol/L (17.6 +/- 2.6 vs. 24.0 +/- 2.2 nmol min-1 mg protein-1; P<0.05), and at 10 mmol/L glucose 6-phosphate (24.1 +/- 3.5 vs. 33.7 +- 2.4 nmol min-1 mg protein-1; P<0.05) and glycogen synthase protein concentrations (8.8 +/- 1.8 vs. 18.9 +/- 1.9 relative units per ng DNA; P<0.01) were lower in kidney transplant patients compared with controls. Glycogen synthase protein correlated with nonoxidative glucose metabolism (r=0.42; P=0.04). Alpha-actinin (used as a control of general protein degradation) was lower in kidney transplant patients compared with controls (4.4 +/- 0.8 vs. 9.6 +/- 1.1 cpm/ng DNA; P<0.01). In conclusion, corticosteroids cause insulin resistance, which correlates with impaired activation of glycogen synthase and decreased enzyme protein content. The decrease in glycogen synthase protein may reflect increased degradation rather than a defect in translation.

Hospital use among diabetic patients and the general population

OBJECTIVE

This register-based linkage study compared hospital use among diabetic and nondiabetic populations. The study focused on overall use, use by disease categories, and inpatient care caused by complications.

RESEARCH DESIGN AND METHODS

The patient data were derived from the Hospital Discharge Register and the Central Drug Register in Finland. All drug-treated diabetic patients and discharges of patients in a 3-year period were included in the study. Hospital use was measured by inpatient days, mean length of stay, and discharge rate.

RESULTS

Among diabetic patients were eligible for drug reimbursement, 14.2% had at least one hospital stay because of diabetes in a year, while 50.7% had at least one hospital stay for any cause. Only 12.4% of the nondiabetic population was hospitalized annually. Patients with diabetes as the principal diagnosis consumed about 3% of all inpatient days; patients who had diabetes either as the principal or as a subsidiary diagnosis used 8.3%; and people who were eligible for antidiabetic drug reimbursement used 13.3% of total inpatient days. Among diabetic children, the risk for hospitalization was 6.5 times higher than among nondiabetic children. With advancing age, causes other than diabetes increasingly dominated hospitalization among diabetic patients. Inpatient days because of cardiovascular diseases were 1.6-18 times more common among diabetic patients than among nondiabetic patients, depending on gender and age-group. Diabetic patients used many more hospital inpatient days than did the nondiabetic population for a number of other disease categories that are usually not related to diabetes.

CONCLUSIONS

Hospital use among diabetic patients is substantially greater than that among the nondiabetic population, mainly because of cardiovascular and microvascular complications, but also because of diseases unrelated to diabetes.

Contribution of muscle and liver to glucose-fatty acid cycle in humans

To examine the influence of elevated free fatty acid (FFA) levels on hepatic glucose production (HGP) and oxidative and nonoxidative pathways of glucose metabolism, 12 healthy subjects participated in two euglycemic insulin-clamp studies performed with and without infusion of Intralipid plus heparin. To elucidate the role of skeletal muscle in this putative interaction, we performed muscle biopsies for the measurement of activities of glycogen synthase (GS), pyruvate dehydrogenase (PDH), and carnitine palmitoyltransferase (CPT). Infusion of Intralipid plus heparin caused an increase in plasma FFA concentrations and rate of lipid oxidation (measured by indirect calorimetry) that was not inhibited by insulin. Suppression of HGP by insulin was impaired by elevated plasma FFA levels. Furthermore, the increase in plasma FFA was associated with a 20% reduction in total glucose metabolism (P < 0.01), which was completely accounted for by a reduction in the rate of glucose oxidation. Although the fractional activity of GS was increased by insulin, elevation of plasma FFA had no influence on this key enzyme of glycogen synthesis. In addition, the activities of PDH and CPT were uninfluenced by the elevation of FFA, suggesting that oxidative processes in skeletal muscle were not a major target for the operative glucose-fatty acid cycle under the current conditions. Taken together, the data indicate that the interaction between FFA and glucose metabolism also involves impaired suppression of HGP by insulin.

Metabolism of HDL apolipoprotein A-I and A-II in type 1 (insulin-dependent) diabetes mellitus

Concentrations of HDL cholesterol and apolipoprotein A-I are commonly increased in Type 1 (insulin-dependent) diabetes mellitus but the mechanisms whereby diabetes influences HDL metabolism have not been studied. We investigated the metabolism of HDL apoproteins A-I and II in normolipidaemic Type 1 diabetic men (n = 17, HbA1 6.4-11.9%) without microalbuminuria but with a wide range of HDL cholesterol (0.85-2.10 mmol/l) and in nondiabetic men (n = 18) matched for body mass index and the range of HDL cholesterol. Input rates and fractional catabolic rates for apolipoproteins A-I and II were determined following injection of 125I-apolipoprotein A-I and 131I-apolipoprotein A-II tracers. Additional multicompartmental analysis was performed using a model to describe the kinetics of HDL particles containing only apolipoprotein A-I (Lp A-I) and apolipoprotein A-I and apolipoprotein A-II (Lp A-I/A-II). No gross differences from normal subjects were observed in the mean levels of lipids, lipoproteins, apoproteins and the lipolytic enzymes in the diabetic men as a result of the selection process. Furthermore, the relationship between apolipoprotein A kinetics and plasma HDL cholesterol levels appeared to be preserved in the diabetic group. However, some normal interrelationships were disrupted in the diabetic men. Firstly, the rate of apolipoprotein A-II synthesis was 22% lower than in control subjects (p less than 0.05). Modelling indicated that this was due to decreased input of Lp A-I/A-II particles whereas the input of Lp A-I particles was similar in the two groups. Secondly, there was no correlation between VLDL triglyceride and HDL cholesterol or VLDL triglyceride and the fractional catabolic rate of apolipoproteins A-I and A-II in diabetic men in contrast to that seen in control subjects. We conclude that there is a disruption in the normal association between VLDL and HDL metabolism in Type 1 diabetic men and postulate that the observed differences may be due to the therapeutic use of exogenous insulin.

Correlation of HbA1C, glycated serum proteins and albumin, and fructosamine with the 24-h glucose profile of insulin-dependent pregnant diabetics

To assess the value of various methods for long-term follow-up of diabetic patients, we compared the concentrations of fructosamine in serum with those of various glycated proteins: hemoglobin (HbA1C), total serum proteins (G-prot), and albumin (G-alb), assayed in 30 pregnant insulin-dependent diabetics every two weeks after initial determination of a 24-h blood glucose profile. HbA1C correlated best with the 24-h glucose profile during the succeeding 10-35 days (r = 0.65-0.68, P less than 0.001). G-prot and G-alb correlated nearly as well as HbA1C 10-20 days after the glucose profile (r = 0.54-0.64, P less than 0.01-0.001), but only weakly after 25-35 days. Values for fructosamine did not correlate significantly with the glucose profile 10-35 days after it (r = 0.23-0.36). Evidently the fructosamine assay is not an adequate alternative to HbA1C, G-alb, or G-prot as an index to long-term control of blood glucose in such patients.

Correlation of HbA1C, glycated serum proteins and albumin, and fructosamine with the 24-h glucose profile of insulin-dependent pregnant diabetics

To assess the value of various methods for long-term follow-up of diabetic patients, we compared the concentrations of fructosamine in serum with those of various glycated proteins: hemoglobin (HbA1C), total serum proteins (G-prot), and albumin (G-alb), assayed in 30 pregnant insulin-dependent diabetics every two weeks after initial determination of a 24-h blood glucose profile. HbA1C correlated best with the 24-h glucose profile during the succeeding 10-35 days (r = 0.65-0.68, P less than 0.001). G-prot and G-alb correlated nearly as well as HbA1C 10-20 days after the glucose profile (r = 0.54-0.64, P less than 0.01-0.001), but only weakly after 25-35 days. Values for fructosamine did not correlate significantly with the glucose profile 10-35 days after it (r = 0.23-0.36). Evidently the fructosamine assay is not an adequate alternative to HbA1C, G-alb, or G-prot as an index to long-term control of blood glucose in such patients.

Immunoblotting analysis of class-specific antibody response in patients with primary HSV infection

Class-specific immune response in acute herpes simplex virus (HSV) infections to individual virus specified polypeptide antigens was analysed by immunoblotting. The HSV specified glycoproteins B (gB), C (gC), and D (gD) were detected. IgG-antibody response was shown to develop to various other virus specific polypeptides as well. The IgM- and IgA-antibody responses remained restricted to only a few HSV specific proteins, namely VP 13 (80 kD), VP 20 (52 kD), and VP 23 (40 kD) and to the low molecular weight polypeptides.

Phospholipase A2 activity is copurified together with herpes simplex virus-specified Fc receptor proteins

We purified Fc-binding proteins from herpes simplex virus (HSV)-infected Vero cells by using an inverse immunoaffinity column chromatography. Polyacrylamide gel electrophoresis analysis revealed a single, virus-specific 65-kd polypeptide both in HSV type 1- and HSV type 2-infected cell-derived preparations. A Ca2+-dependent phospholipase A2 activity was demonstrated to be associated with the viral Fc-binding proteins.

Comparison of insulin regimens in the therapy of type 1 diabetes

The major problems with one or two daily subcutaneous injections of fast and intermediate acting insulins are morning hyperglycaemia and nocturnal hypoglycaemia. These problems can be avoided to a great extent by giving a third injection at bedtime. However, the kinetics of plasma free insulin during these insulin regimens is unphysiological and appropriate meal related plasma insulin peaks cannot be achieved. The new intensified methods of insulin delivery, multiple daily injections (MDI) and continuous subcutaneous insulin infusion (CSII) are more physiological. Consequently, a near normal glycaemic control can be achieved with these regimens; more often with CSII than with MDI. The risk of complications of CSII is on the other hand slightly greater. The importance and need of intensified insulin therapy in the treatment of insulin dependent diabetes is not yet fully settled. At the present it is not a primary form of treatment and indicated only if the conservative insulin regimens fail.

Serum antibodies to the major HSV-2-specified DNA-binding protein in patients with an acute HSV infection or cervical neoplasia

The major HSV-2-specified DNA-binding protein (ICSP 11/12) was purified from HSV-2-infected cells. ELISA and immunoblotting techniques were used to study its antigenicity in HSV-infected patients and patients with cervical neoplasia and control women. Patients with an acute HSV-2 infection had clearcut antibody responses to the purified ICSP 11/12 preparation. Determination of the ICSP 11/12 antibodies by ELISA revealed considerably higher serum antibody levels in patients with cervical carcinoma than in the controls.

Immunoblotting and enzyme-linked immunosorbent assay analysis of serological responses in patients infected with herpes simplex virus types 1 and 2

Serological responses to soluble membrane and cytoplasmic antigens specified by herpes simplex type 1 (HSV1) and 2 (HSV2) were studied by immunoblotting and by enzyme-linked immunosorbent assay (ELISA). In the immunoblotting test, polypeptides migrating like the HSV1-specified glycoprotein C showed type-specific reactivity but could not always be detected. The immunoblotting and ELISA results were in agreement when antibody responses to HSV1- and HSV2-specified antigens were compared, and they allowed the identification of patients with HSV2 and/or HSV1 antibodies.

Purification of herpes simplex virus-specified major DNA-binding proteins and detection of antibodies to them in human and rabbit sera

We purified herpes simplex virus type 1 and 2-specified nonstructural DNA-binding proteins (ICP8 and ICSP 11/12, respectively) from infected Vero cells and applied them in ELISA test to analyse human and rabbit sera. Only a weak immune response to the ICP8 and ICSP 11/12 could be demonstrated following experimental HSV-1 or HSV-2 infections of rabbits. Low levels of ICSP8 antibodies were found also in acute HSV infections of man.

Adrenergic blockade alters glucose kinetics during exercise in insulin-dependent diabetics

We investigated the effects of alpha and/or beta adrenergic blockade (with phentolamine and/or propranolol) on glucose homeostasis during exercise in six normal subjects and in seven Type I diabetic subjects. The diabetics received a low dose insulin infusion (0.07 mU/kg X min) designed to maintain plasma glucose at approximately 150 mg/dl. In normals, neither alpha, beta, nor combined alpha and beta adrenergic blockade altered glucose production, glucose uptake, or plasma glucose concentration during exercise. In diabetics, exercise alone produced a decline in glucose concentration from 144 to 116 mg/dl. This was due to a slightly diminished rise in hepatic glucose production in association with a normal increase in glucose uptake. When exercise was performed during beta adrenergic blockade, the decline in plasma glucose was accentuated. An exogenous glucose infusion (2.58 mg/kg X min) was required to prevent glucose levels from falling below 90 mg/dl. The effect of beta blockade was accounted for by a blunted rise in hepatic glucose production and an augmented rise in glucose utilization. These alterations were unrelated to changes in plasma insulin and glucagon levels, which were similar in the presence and absence of propranolol. In contrast, when the diabetics exercised during alpha adrenergic blockade, plasma glucose concentration rose from 150 to 164 mg/dl. This was due to a significant increase in hepatic glucose production and a small decline in exercise-induced glucose utilization. These alterations also could not be explained by differences in insulin and glucagon levels. We conclude that the glucose homeostatic response to exercise in insulin-dependent diabetics, in contrast to healthy controls, is critically dependent on the adrenergic nervous system.

Influence of physical training on the fuel-hormone response to prolonged low intensity exercise

The effects of physical training on the fuel-hormone response to prolonged (3 hr), low intensity cycle ergometer exercise (40% maximal aerobic power) which in the untrained state fails to produce a rise in blood lactate, was examined in six healthy male subjects. The training program consisted of one hour cycle ergometer exercise performed 4 times weekly for 6 weeks and resulted in a 19% increase in maximal aerobic power. Prior to training, prolonged low intensity exercise resulted in a 20% decline in plasma glucose, a 2.5-fold rise in plasma free fatty acids (FFA), a 7-fold rise in plasma epinephrine, a 3-fold elevation in plasma norepinephrine, and a 2.5-fold rise in plasma glucagon. Following training, the exercised-induced decline in glucose was 60% less than before training, the elevations in plasma FFA and norepinephrine were respectively, 45% and 90% less than before training and no significant increment in plasma norepinephrine and glucagon was observed. Training also blunted the exercise-induced elevations in circulating ketones and growth hormone and resulted in a lower respiratory exchange ratio during exercise. The data indicate that training markedly diminishes the fuel-hormone perturbations associated with low intensity exercise and in the face of a lessened increment in plasma FFA results in a greater utilization of fat and less dependence on carbohydrate during the exercise.

Urinary 3-methylhistidine excretion in juvenile-onset diabetics: evidence of increased protein catabolism in the absence of ketoacidosis

Urinary 3-methylhistidine excretion (an indicator of protein catabolism) was measured in ten diabetic patients and in age and weight matched control subjects. The diabetic group, while receiving their usual insulin dose, excreted 42% more 3-methylhistidine than the control group (2.7 versus 1.9 mumole/kg body weight/24 hr). When the insulin dose of the diabetic subject was reduced by 15% or 25%, the concentrations of blood and urinary glucose were significantly increased by the rate of urinary 3-methylhistidine excretion was not increased further. These findings demonstrate augmented protein catabolism in diabetics even in the absence of ketoacidosis. It appears that blood and urine glucose levels are more sensitive to changes in insulin availability than protein catabolism.

Normalization of the growth hormone and catecholamine response to exercise in juvenile-onset diabetic subjects treated with a portable insulin infusion pump

The plasma growth hormone, epinephrine, and norephinephrine responses to cycle ergometer exercise (15 min at 1 W/kg) were examined in 10 juvenile-onset, insulin-dependent diabetics (ages 10–32 yr) during conventional insulin treatment and after 7 and 14 days of treatment with a portable subcutaneous insulin infusion system that normalizes plasma glucose. During conventional insulin treatment (mean plasma glucose, 205 ± 22 mg/dl), the growth hormone response to exercise was sevenfold greater than in normal controls (P &lt; 0.01). After 1 wk of insulin pump treatment (mean plasma glucose, 89 ± 3), the growth hormone response fell 62% (P &lt; 0.001); by 2 wk the growth hormone response had fallen 83% (P &lt; 0.001) to values comparable to those of controls. Exercise resulted in a two- to threefold rise in plasma epinephrine in diabetics (P &lt; 0.001) during conventional treatment but failed to elicit a consistent increment in epinephrine in normal control subjects or in the diabetic patients after 14 days of pump treatment. The rise in plasma norepiriephrine after exercise in conventionally treated diabetic patients was 12-fold greater than in healthy control subjects (P &lt; 0.025) but fell 82% (P &lt; 0.001) after 7 days and 88% (P &lt; 0.001) after 14 days of pump treatment to values similar to those of controls. These data indicate that treatment of insulin-dependent diabetics with a subcutaneous portable insulin infusion system that normalizes plasma glucose results in normalization of the growth hormone and catecholamine response to exercise within 7 to 14 days of institution of treatment.