Role of orlistat in the treatment of obese patients with type 2 diabetes. A 1-year randomized double-blind study

OBJECTIVE

Obesity is an important risk factor for type 2 diabetes. Weight loss in patients with type 2 diabetes is associated with improved glycemic control and reduced cardiovascular disease risk factors, but weight loss is notably difficult to achieve and sustain with caloric restriction and exercise. The purpose of this study was to assess the impact of treatment with orlistat, a pancreatic lipase inhibitor, on weight loss, glycemic control, and serum lipid levels in obese patients with type 2 diabetes on sulfonylurea medications.

RESEARCH DESIGN AND METHODS

In a multicenter 57-week randomized double-blind placebo-controlled study, 120 mg orlistat or placebo was administered orally three times a day with a mildly hypocaloric diet to 391 obese men and women with type 2 diabetes who were aged > 18 years, had a BMI of 28-40 kg/m2, and were clinically stable on oral sulfonylureas. Changes in body weight, glycemic control, lipid levels, and drug tolerability were measured.

RESULTS

After 1 year of treatment, the orlistat group lost 6.2 +/- 0.45% (mean +/- SEM) of initial body weight vs. 4.3 +/- 0.49% in the placebo group (P < 0.001). Twice as many patients receiving orlistat (49 vs. 23%) lost > or = 5% of initial body weight (P < 0.001). Orlistat treatment plus diet compared with placebo plus diet was associated with significant improvement in glycemic control, as reflected in decreases in HbA1c (P < 0.001) and fasting plasma glucose (P < 0.001) and in dosage reductions of oral sulfonylurea medication (P < 0.01). Orlistat therapy also resulted in significantly greater improvements than placebo in several lipid parameters, namely, greater reductions in total cholesterol, (P < 0.001), LDL cholesterol (P < 0.001), triglycerides (P < 0.05), apolipoprotein B (P < 0.001), and the LDL-to-HDL cholesterol ratio (P < 0.001). Mild to moderate and transient gastrointestinal events were reported with orlistat therapy, although their association with study withdrawal was low. Fat-soluble vitamin levels generally remained within the reference range, and vitamin supplementation was required in only a few patients.

CONCLUSIONS

Orlistat is an effective treatment modality in obese patients with type 2 diabetes with respect to clinically meaningful weight loss and maintenance of weight loss, improved glycemic control, and improved lipid profile.

Metabolic effects of troglitazone monotherapy in type 2 diabetes mellitus. A randomized, double-blind, placebo-controlled trial

BACKGROUND

Troglitazone is a new insulin-sensitizing agent used to treat type 2 diabetes mellitus. The mechanism by which troglitazone exerts its effect on systemic glucose metabolism is unknown.

OBJECTIVE

To determine the effects of 6 months of troglitazone monotherapy on glucose metabolism in patients with type 2 diabetes mellitus.

DESIGN

Randomized, double-blind, placebo-controlled trial.

SETTING

Six general clinical research centers at university hospitals.

PATIENTS

93 patients (mean age, 52 years) with type 2 diabetes mellitus (mean fasting plasma glucose level, 11.2 mmol/L) who were being treated with diet alone or who had discontinued oral antidiabetic medication therapy.

INTERVENTION

Patients were randomly assigned to one of five treatment groups (100, 200, 400, or 600 mg of troglitazone daily or placebo) and had metabolic assessment before and after 6 months of treatment.

MEASUREMENTS

Plasma glucose and insulin profiles during a meal tolerance test; basal hepatic glucose production and insulin-stimulated glucose disposal rate during a hyperinsulinemic-euglycemic clamp procedure.

RESULTS

Troglitazone at 400 and 600 mg/d decreased both fasting (P < 0.001) and postprandial (P = 0.016) plasma glucose levels by approximately 20%. All four troglitazone dosages also decreased fasting (P = 0.012) and postprandial (P < 0.001) triglyceride levels; 600 mg of the drug per day decreased fasting free fatty acid levels (P = 0.018). Plasma insulin levels decreased in the 200-, 400-, and 600-mg/d groups (P < 0.001), and C-peptide levels decreased in all five study groups (P < 0.001). Basal hepatic glucose production was suppressed in the 600-mg/d group compared with the placebo group (P = 0.02). Troglitazone at 400 and 600 mg/d increased glucose disposal rate by approximately 45% above pretreatment levels (P = 0.003). Stepwise regression analysis showed that troglitazone therapy was the strongest predictor of a decrease in fasting (P < 0.001) or postprandial (P = 0.01) glucose levels. Fasting C-peptide level was the next strongest predictor (higher C-peptide level equaled greater glucose-lowering effect).

CONCLUSION

Troglitazone monotherapy decreased fasting and postprandial glucose levels in patients with type 2 diabetes, primarily by augmenting insulin-mediated glucose disposal.

Synergistic effects of 13-cis retinoic acid and arachidonic acid cascade inhibitors on growth of head and neck squamous cell carcinoma in vitro

Products of arachidonic acid metabolism can influence normal and malignant cell growth. In vivo, inhibitors of arachidonic acid metabolism have been associated with inhibition of tumor growth, including head and neck squamous cell carcinoma (HNSCC). This has not been evaluated extensively in vitro in an HNSCC model. Therefore we investigated the effects of several arachidonic acid cascade inhibitors (AACIs) (indomethacin, curcumin, phenidone, nordihydroguaiaretic acid, 5,8,11,14-eicosatetraynoic acid, and 13-cisretinoic acid) on the growth of two HNSCC cell lines (MDA 886Ln and 1483). We found that AACIs caused dose-dependent growth inhibition of both cell lines. In an effort to inhibit HNSCC cell growth at lower concentrations of these drugs, we evaluated the effects of a variety of AACIs in combination with 13-cis retinoic acid. We observed synergistic growth inhibition when the drugs were used in all combinations, with the exception of indomethacin. These results suggest that AACIs may have some utility in the direct treatment of HNSCC, and a strategy combining 13-cis retinoic acid with other AACIs may prove to be even more effective.

Radar detection of the nucleus and coma of comet hyakutake

Radar observations of comet Hyakutake (C/1996 B2) made at the Goldstone Deep Space Communications Complex in California have detected echoes from the nucleus and from large grains in the inner coma. The nucleus of this bright comet was estimated to be only 2 to 3 kilometers in diameter. Models of the coma echo indicate backscatter from porous, centimeter-size grains ejected anisotropically at velocities of tens of meters per second. The radar observations suggest that a comet's activity may be a poor indicator of its size and provide evidence that large grains constitute an important component of the mass loss from a typical active comet.

Androgen biosynthesis and secretion in developing Xenopus laevis

In the frog, Xenopus laevis, castration or anti-androgen treatment during late tadpole or early juvenile stages blocks masculinization of vocal neuroeffectors in males while exogenous androgen or a testicular transplant masculinizes vocal neuroeffectors in females. To elucidate the relation between androgen secretion and the process of masculinization, we measured androgens by radioimmunoassay in adults, juveniles, and tadpoles. In adult females, values for both testosterone (T) and dihydrotestosterone (DHT) were essentially identical during the winter and the summer while in males, summer values for both androgens were 7 to 8x winter values. For DHT, circulating values in males significantly exceeded those in females in both winter and summer while for T, values differed significantly only in summer. Sex differences in circulating androgen arise at late juvenile stages (PM4 and PM5); T values are higher in males than in females and higher, for both sexes, in winter than in summer. During early juvenile stages (PM1-PM3), there were no seasonal or sex differences in circulating androgens. While androgens were detected in liver during late tadpole stages (stage 56-66), no sex differences were apparent. Androgens can be detected in tadpole tissues, as early as tadpole stage 47. delta 5-3 beta-Hydroxysteroid dehydrogenase (HSD) histochemistry indicates that tadpole gonads and interrenals (and, to a much lesser extent, kidneys) are the only tissues capable of steroid biosynthesis. Interrenal HSD activity was present throughout tadpole development; in gonads, activity began before sexual differentiation. Thin-layer chromatographic separation of steroid metabolites following in vitro incubation with radioactive precursors indicated that the interrenals were more active than the gonads in tadpoles but not in juveniles. Thus, interrenals and gonads of developing X. laevis can synthesize delta 4 steroids (which include androgens) and, from early tadpole stages, are capable of metabolizing pregnenolone and testosterone, early and late compounds in the steroid synthetic pathway, respectively. The absence of dramatic sex differences in T or DHT levels during late tadpole and early juvenile stages suggests that while necessary, androgen secretion is not sufficient for masculinization of vocal neuroeffectors.

Impaired postprandial glucose utilization in non-insulin-dependent diabetes mellitus

The importance of impaired glucose utilization in the pathogenesis of postprandial hyperglycemia in non-insulin-dependent diabetes mellitus (NIDDM) is controversial. Three methods were used to assess glucose utilization following ingestion of a mixed meal in 18 NIDDM and 12 nondiabetic subjects. Dual glucose isotopes were used to determine first-pass splanchnic glucose uptake, suppression of endogenous glucose production, and systemic glucose utilization. Leg balance was used to evaluate skeletal muscle glucose metabolism, and systemic and limb indirect calorimetry were used to assess glucose and lipid oxidation. NIDDM subjects had marked postprandial hyperglycemia as compared with nondiabetics (15.35 +/- 0.72 v 5.83 +/- 0.28 mmol, P < .001), accompanied by lower postprandial insulin (179 +/- 25 v 253 +/- 46 pmol, P < .01) and elevated plasma free fatty acids ([FFA] 569 +/- 34 v 314 +/- 20 mumol/L, P < .001). Cumulative postprandial glucose appearance was nearly twofold greater in NIDDM (82.2 +/- 4.7 v 48.7 +/- 4.9 g.5h, P < .001) due to increased endogenous glucose production (56.4 +/- 4.8 v 24.5 +/- 1.9 g, P < .001), whereas first-pass splanchnic uptake of ingested glucose was normal in NIDDM. Cumulative postprandial glucose utilization in NIDDM, after correction for urinary glucose, was unchanged from postabsorptive rates, a pattern also found for postprandial glucose oxidation. Cumulative leg glucose uptake was somewhat less in NIDDM subjects (123 +/- 18 v 173 +/- 14 mumol/100 mL leg tissue.5 h, P = .06), whereas lactate and alanine net release across the leg were nevertheless twofold greater in NIDDM (P = .04) and accounted for nearly half of the leg glucose metabolism in NIDDM.(ABSTRACT TRUNCATED AT 250 WORDS)

Tumor necrosis factor-alpha plays a central role in interleukin-2-induced pulmonary vascular leak and lymphocyte accumulation

Administration of interleukin-2 (IL-2) leads to pulmonary vascular leak. This form of pulmonary edema has previously been postulated to be due to the in vivo induction of tumor necrosis factor-alpha (TNF-alpha). To determine whether TNF-alpha plays a role in IL-2-induced pulmonary vascular leak, we performed in situ hybridization of lung sections and reverse transcriptase-polymerase chain reaction of bronchoalveolar lavage macrophages from IL-2-challenged mice. The results confirm an in situ upregulation of TNF-alpha mRNA expression in the lungs associated with vascular leak. In addition, a significant increase in TNF-alpha protein production was found in the lung following IL-2 administration, as measured by TNF-alpha-specific ELISA of lung supernatants (P = 0.028). Intravenous administration of a soluble TNF receptor significantly diminished IL-2-induced pulmonary vascular leak (P = 0.006). These findings confirm a central role for TNF-alpha in mediating the pulmonary vascular leak associated with IL-2 toxicity.

An androgen receptor mRNA isoform associated with hormone-induced cell proliferation

The larynx of male Xenopus laevis undergoes an androgen-driven developmental transformation that enables the adult to produce his complex mate attraction song. During the early postmetamorphic period, androgen directs proliferation and differentiation of laryngeal muscle and cartilage. To explore the cellular and molecular basis of androgen control, we have cloned an androgen receptor cDNA from juvenile larynx. Here we identify two androgen receptor mRNA isoforms, alpha and beta, differing within the A/B, or hypervariable, domain. Northern blot analyses reveal that the beta isoform is transiently expressed during early juvenile stages, whereas the alpha transcript is expressed throughout postmetamorphic life. Using in situ hybridization and [3H]thymidine autoradiography, we examined the expression of androgen receptor mRNA isoforms during androgen-evoked cell proliferation and differentiation. The alpha and beta transcripts are coexpressed in proliferating tissues of the juvenile larynx; in postmitotic differentiated tissues, only the alpha transcript is expressed. Because androgen receptor beta mRNA is specifically expressed during hormone-evoked cell proliferation, we propose that this developmentally regulated mRNA isoform is required for the masculine program of cell addition within the developing vocal organ.

Interleukin-2-responsive wound-infiltrating lymphocytes in surgical adjuvant cancer immunotherapy

Wound-infiltrating lymphocytes (WIL) were assessed in murine models of localized sarcoma and carcinoma to evaluate the role of interleukin-2 (IL-2)-responsive lymphocytes in adjuvant immunotherapy. Following tumor resection, IL-2 or diluent was injected at the surgical site for 6 days. Surgical site tissues were harvested and digested in a triple enzyme mixture, and single cell suspensions were prepared. Thy 1.2+ lymphocytes were isolated by incubating cells with monoclonal anti-Thy 1.2 antibody-coated magnetic beads. Lymphocyte-bead complexes were extracted with a magnet and cultured in medium containing IL-2 (100 units/ml) for 1-3 weeks. Perioperative IL-2 immunotherapy led to a three- to four-fold increase in WIL yield. WIL from IL-2-treated mice also demonstrated enhanced cytolysis of the autologous tumor and bound to activated endothelial cells with greater avidity than did the controls. We conclude that perioperative IL-2 therapy augments the yield, as well as the cytolytic and adhesive properties, of wound-infiltrating lymphocytes.

Genetic modification of a murine fibrosarcoma to produce interleukin 7 stimulates host cell infiltration and tumor immunity

Retroviral-mediated gene transfer was used to introduce and express the gene for murine interleukin 7 (IL-7) in a fibrosarcoma tumor (FSA). The tumorigenicity of these genetically modified FSA cells was greatly decreased in immunologically intact syngeneic mice but was unaltered in T-cell-deprived mice. IL-7-infected tumors that did grow in intact animals from large size inocula did so slowly and had a high incidence of spontaneous regression. Furthermore, mice that had rejected tumors became specifically immune to challenge with uninfected parental tumor cells. IL-7-infected FSA growing in intact mice were heavily infiltrated with host T-cells that were presumably responsible for slow growth and tumor regression, and tumor cells were in the minority. Fluorescence-activated cell sorter analysis showed that there was a 530% increase in T-cells in IL-7-infected FSA compared with control tumors. CD8+ T-cells were particularly elevated, but CD4+ lymphocytes were also increased in number, as were eosinophils and basophils. The CD4+:CD8+ ratio in IL-7-infected FSA was 1:1.7 in comparison to 1:0.6 in control tumors. Lymphocytes isolated from IL-7-producing tumors had greatly enhanced cytotoxicity towards uninfected, parental FSA cells. Killing of non-cross-reacting fibrosarcoma line was also increased but to a much lesser extent. Injection of recombinant human IL-7 directly into established FSA tumors slowed their growth and, in a significant number of instances, caused complete regression. Mice that had rejected tumor became specifically immune. The dose that was needed for this effect was, however, somewhat large: 20 micrograms twice daily for 10 days. This result contrasts with the efficacy of IL-7 gene infection in stimulating responses to the same tumor. These considerations make IL-7 a good candidate for tumor-directed cytokine gene therapy.

Effects of β-2 microglobulin anti-sense oligonucleotides on sensitivity of HER2/neu oncogene-expressing and nonexpressing target cells to lymphocyte-mediated lysis

The mechanism by which HER2/neu overexpressing tumor cells resist NK, LAK, and LDCC cytotoxic lymphocytes was investigated. Resistance was not explained by a delay in kinetics of lysis, concurrent resistance to TNF, or a diminished expression of the transferrin receptor. HLA-class I expression, however, was markedly elevated compared to HER2 nonexpressing targets suggesting a reason for resistance. To test the role of class I, we selectively decreased expression by incubation of targets with beta-2 microglobulin anti-sense oligonucleotides. Anti-sense-treated HER2+ targets, displaying levels of class I comparable to HER2- targets, were still markedly resistant to cytotoxic effectors. Down-regulation of class I expression in HER2- carcinoma cells also had no effect on sensitivity to cytotoxicity by anti-sense treatment of Raji and U937 targets resulted in enhanced sensitivity to NK and LAK effectors but not to T cells mediating LDCC. These data indicate resistance to cytotoxicity in HER2-expressing targets cannot be solely explained by heightened expression of class I. The data also support the concept that class I expression regulates sensitivity to NK and LAK cells (but not LDCC effectors) in selected targets.

Burns in alcohol and drug users result in longer treatment times with more complications

Brezel, Kassenbrock, and Stein (J Burn Care Rehabil 1988;9:169-71), surveyed a group of 180 patients who were substance abusers or who were neurologically or mentally impaired and found that their inpatient care was more costly, more complicated, and more lengthy. In our institution we undertook a similar study to determine whether our findings would be similar. During a 12-month period, the charts of all patients over the age of 18 who were admitted for treatment of acute burns were reviewed. One hundred and thirty-one charts were available for study. Review of the charts revealed that 19 (14.5%) met our criterion of being impaired by drugs or alcohol, and the remaining 112 patients served as control subjects. The total body surface area burn averaged 25.8% in the impaired group and 21.3% in the control group. The amount of third-degree burns averaged 11% in the impaired group and 11% in the control group. Although the amount of third-degree burns was virtually identical in the two groups, the control group required an average of 1.2 procedures per patient, whereas the impaired group required 2.1 procedures per patient. A list of possible complications or adverse reactions that could occur was used to compare the two groups. The control group averaged 1.83 complications per patient, and the impaired group averaged 3.16 complications per patient. The average length of stay in the hospital for the control group was 19 days, and the average length of stay for the impaired group was 34.1 days.(ABSTRACT TRUNCATED AT 250 WORDS)

Role of reduced suppression of glucose production and diminished early insulin release in impaired glucose tolerance

BACKGROUND

Insulin resistance and impaired insulin secretion both occur in non-insulin-dependent diabetes (NIDDM), but their relative importance is unclear. Hyperglycemia itself has adverse effects on tissue insulin sensitivity and insulin secretion that make it difficult to distinguish between primary and secondary abnormalities. To avoid this problem we studied subjects with postprandial glucose intolerance but not sustained hyperglycemia.

METHODS

We compared the rate of systemic appearance and disappearance of glucose, the output of endogenous hepatic glucose, splanchnic and muscle uptake of glucose, and plasma insulin and glucagon responses after the ingestion of 1 g of glucose per kilogram of body weight in 15 subjects with impaired glucose tolerance (8 of them nonobese and 7 obese) and in 16 normal subjects (9 nonobese and 7 obese) who were matched for age and weight.

RESULTS

After glucose ingestion the mean (+/- SE) rate of total systemic appearance of glucose was significantly higher in both the nonobese subjects (455 +/- 12 mmol per five hours) and the obese subjects (486 +/- 17 mmol per five hours) with impaired glucose tolerance than in the respective normal subjects (411 +/- 11 and 436 +/- 7 mmol per five hours). This difference was fully accounted for by the reduced suppression of endogenous hepatic glucose in the subjects with impaired glucose tolerance (a reduction of about 28 percent, vs. 48 percent in the normal subjects; P less than 0.01). Despite late hyperinsulinemia, at 30 minutes the subjects with impaired glucose tolerance had smaller increases in plasma insulin and smaller reductions in plasma glucagon (both P less than 0.01). Molar ratios of plasma insulin to plasma glucagon levels correlated inversely (r = -0.62, P less than 0.001) with the rates of systemic glucose appearance; the latter correlated positively (r = 0.72, P less than 0.0001) with peak plasma glucose concentrations.

CONCLUSIONS

Impaired glucose tolerance, the precursor of NIDDM, results primarily from reduced suppression of hepatic glucose output due to abnormal pancreatic islet-cell function. The late hyperinsulinemia may be the consequence of an inadequate early beta-cell response rather than of insulin resistance.

Contribution of abnormal muscle and liver glucose metabolism to postprandial hyperglycemia in NIDDM

To assess the role of muscle and liver in the pathogenesis of postprandial hyperglycemia in non-insulin-dependent diabetes mellitus (NIDDM), we administered an oral glucose load enriched with [14C]glucose to 10 NIDDM subjects and 10 age- and weight-matched nondiabetic volunteers and compared muscle glucose disposal by measuring forearm balance of glucose, lactate, alanine, O2, and CO2 (with forearm calorimetry). In addition, we used the dual-lable isotope method to compare overall rates of glucose appearance (Ra) and disappearance (Rd), suppression of endogenous glucose output, and splanchnic glucose sequestration. During the initial 1-1.5 h after glucose ingestion, plasma glucose increased by approximately 8 mM in NIDDM vs. approximately 3 mM in nondiabetic subjects (P less than 0.01); overall glucose Ra was nearly 11 g greater in NIDDM than nondiabetic subjects (45.1 +/- 2.3 vs. 34.4 +/- 1.5 g, P less than 0.01), but glucose Rd was not significantly different in NIDDM (35.1 +/- 2.4 g) and nondiabetic (33.3 +/- 2.7 g) subjects. The greater overall glucose Ra of NIDDM subjects was due to 6.8 g greater endogenous glucose output (13.7 +/- 1.1 vs. 6.8 +/- 1.0 g, P less than 0.01) and 3.8 g less oral glucose splanchnic sequestration of the oral load (31.4 +/- 1.5 vs. 27.5 +/- 0.9 g, P less than 0.05). Although glucose taken up by muscle was not significantly different in NIDDM and nondiabetic subjects (39.3 +/- 3.5 vs. 41.0 +/- 2.5 g/5 h), a greater amount of the glucose taken up by muscle in NIDDM was released as lactate and alanine (11.7 +/- 1.0 vs. 5.2 +/- 0.3 g in nondiabetic subjects, P less than 0.01), and less was stored (11.7 +/- 1.3 vs. 16.9 +/- 1.5 g, P less than 0.05). We conclude that increased systemic glucose delivery, due primarily to reduced suppression of endogenous hepatic glucose output and, to a lesser extent, reduced splanchnic glucose sequestration, is the predominant factor responsible for postprandial hyperglycemia in NIDDM.

Contribution of impaired muscle glucose clearance to reduced postabsorptive systemic glucose clearance in NIDDM

The reduced postabsorptive rates of systemic glucose clearance in non-insulin-dependent diabetes mellitus (NIDDM) are thought to be the consequence of insulin resistance in peripheral tissues. Although the peripheral tissues involved have not been identified, it is generally assumed to be primarily muscle, the major site of insulin-mediated glucose disposal. To test this hypothesis, we measured postabsorptive systemic and forearm glucose utilization and clearance in 15 volunteers with NIDDM and 15 age- and weight-matched nondiabetic volunteers. Although systemic glucose utilization was increased in NIDDM subjects (14.5 +/- 0.5 vs. 11.2 +/- 0.2 mumol.kg-1.min-1, P less than 0.001), systemic glucose clearance was reduced 1.40 +/- 0.06 vs. 2.13 +/- 0.05 ml.kg-1.min-1, P less than 0.01). Although forearm glucose utilization was increased in NIDDM subjects (0.663 +/- 0.058 vs. 0.411 +/- 0.019 mumol.dl-1.min-1, P less than 0.001), forearm glucose dl-1 clearance was reduced (0.628 +/- 0.044 vs. 0.774 +/- 0.037 ml.L-1.min-1, P less than 0.01). However, extrapolation of forearm data to total-body muscle indicated that impaired clearance reduced muscle glucose disposal by only 61 +/- 21 mumol/min, whereas impaired systemic clearance reduced systemic glucose disposal by 662 +/- 82 mumol/min. Thus, impaired muscle glucose clearance accounted for less than 10% of the reduced systemic glucose clearance in NIDDM subjects. Therefore, we conclude that muscle insulin resistance plays only a minor role in the reduced systemic glucose clearance found in NIDDM in the postabsorptive state and propose that reduced brain glucose clearance is largely responsible.

Hospitalization experience of Navajo subjects with type II diabetes and matched controls: an historical cohort study

Using an historical cohort study design with a 12 year follow-up, we found that 77 Navajo adults with type II diabetes mellitus were hospitalized at a rate of 335 hospitalizations per 1000 patient years compared to a rate of 167 hospitalizations per 1000 patient years for 77 age, sex, and residence matched non-diabetic controls, yielding a risk ratio of 2.0. Using matched pairs analysis (sign test), the observed difference in number of hospital admissions is statistically significant (z = 2.30, p less than 0.05). The average duration of hospitalization, however, was not statistically different in matched pairs analysis (z = 0.95, p greater than 0.05). The 136 excess hospitalizations of the diabetic subjects included 45 admissions for poor metabolic control of diabetes, 50 excess admissions for infectious disease, and 26 excess admissions for conditions of the heart, eye, kidney, or non-traumatic amputation. In multivariate analyses, variables found to be associated with greater hospitalization experience among the 77 diabetic subjects in the 12 years follow-up period included older age at entry to the study, poorer metabolic control early in the study period, and presence of diabetic complications.

Persistent abnormalities of the metabolism of an oral glucose load in insulin-treated type I diabetics

We have compared disposal of an oral glucose load in 12 normal subjects and 10 c-peptide-negative, type I-diabetic subjects, who were treated with insulin (by overnight intravenous insulin infusion followed by a dose of subcutaneous insulin prior to the oral glucose load) to achieve a blood glucose profile that approximated the glucose intolerance commonly seen in insulin-treated diabetics. We used a combination of the dual-isotope and forearm techniques, together with whole-body indirect calorimetry, to quantify the various determinants of glucose tolerance. The diabetic subjects had impaired glucose tolerance in that, despite similar fasting plasma glucose levels (5.46 +/- 0.17 mmol/L v 5.35 +/- 0.10 mmol/L in the normal subjects), they had a higher peak glucose (14.3 +/- 1.2 mmol/L v 10.0 +/- 0.7 mmol/L P less than .01) and area under the glucose curve (2,483 +/- 197 mmol.min/L v 1,525 +/- 43 mmol.min/L P less than .001). Up to 120 minutes after the oral glucose load, the amount of glucose entering the systemic circulation exceeded that leaving by 14.6 +/- 2.3 g in the diabetics and only by 2.6 +/- 0.5 g in the normal subjects (P less than .001), accounting for the higher plasma glucose peak in the diabetics. Total systemic glucose appearance rates were significantly greater in the diabetics between 60 and 120 minutes, and endogenous glucose production suppressed more slowly in diabetics than in the normal subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Pulsatile insulin infusion and glucose-homeostasis in well-controlled type 1 (insulin-dependent) diabetic patients

Pulsatile, intravenous insulin infusion designed to mimic the portal insulin concentrations that emerge physiologically after a meal, has been postulated to improve glucose tolerance in Type 1 (insulin-dependent) diabetic patients. We studied the effects of insulin pulsing (10 i.v. pulses of human insulin of 0.035 U kg-1 idealised body weight were given, each of 20 s duration, with intervals of 6 min, three times per day covered with adequate administration of glucose) on 2 successive days on glucose-tolerance in nine well-controlled Type 1 diabetic patients on continuous subcutaneous insulin infusion therapy (age 26 (7) years, mean (SD); duration of diabetes 10 (7) years; body mass index 23.4 (2.3) kg m-2; HbA1c 6.0 (0.6)%). On the days before and after the insulin pulsing, the patients were subjected to metabolic assessments by an oral glucose tolerance test (1 g glucose kg-1 body weight) 30 min after the subcutaneous injection of 0.15 U kg-1 body weight regular human insulin and a subsequent bicycle-ergometer test. During these metabolic assessments, plasma free insulin concentrations, plasma glucagon and the non-protein respiratory quotient remained unaffected by the insulin pulsing. However, glucose tolerance deteriorated significantly (maximal glucose concentration 120 min after glucose load was 10.0 mmol l-1 before and 13.9 mmol l-1 after insulin pulsing, P less than 0.01). In conclusion, the pattern of insulin pulsing used in this study did not ameliorate oral glucose homeostasis in well-controlled Type 1 (insulin dependent) diabetic patients.