Metabolic and hormonal studies of type 1 (insulin-dependent) diabetic patients after successful pancreas and kidney transplantation

Hypoglycemia

Hypoglycemia remains a common problem for patients with diabetes and is associated with substantial morbidity and mortality. This article summarizes our current knowledge of the epidemiology, pathogenesis, risk factors, and complications of hypoglycemia in patients with diabetes and discusses prevention and treatment strategies.

Transplantation of the pancreas

Pancreas transplantation consistently induces insulin-independence in beta-cell-penic diabetic patients, but at the cost of major surgery and life-long immunosuppression. One year after grafting, patient survival rate now exceeds 95 % across recipient categories, while insulin independence is maintained in some 85 % of simultaneous pancreas and kidney recipients and in nearly 80 % of solitary pancreas transplant recipients. The half-life of the pancreas graft currently averages 16.7 years, being the longest among extrarenal grafts, and substantially matching the one of renal grafts from deceased donors. The difference between expected (100 %) and actual insulin-independence rate is mostly explained by technical failure in the postoperative phase, and rejection in the long-term period. Death with a functioning graft remains a further major issue, especially in uremic patients who have undergone prolonged periods of dialysis. Refinements in graft preservation, surgical techniques, immunosuppression, and prophylactic treatments are expected to further improve the results of pancreas transplantation.

Glucose metabolism after pancreas-kidney transplantation

Simultaneous pancreas-kidney (SPK) transplantation is a promising treatment option for patients with type 1 diabetes and end-stage renal disease. Most of these patients can achieve normalization of glucose and hemoglobin A(1c) levels. Patient and graft survival continues to improve; however, defects in beta-cell function and insulin resistance can be seen over time after transplant. Various methods can be used to assess the SPK recipient for the development of hyperglycemia and graft dysfunction, with treatment aimed at minimizing diabetogenic immunosuppression, using agents that may preserve beta-cell function, and improving insulin resistance.

Pancreas transplantation: indications and consequences

Pancreas transplantation continues to evolve as a strategy in the management of diabetes mellitus. The first combined pancreas-kidney transplant was reported in 1967, but pancreas transplant now represents a number of procedures, each with different indications, risks, benefits, and outcomes. This review will summarize these procedures, including their risks and outcomes in comparison to kidney transplantation alone, and how or if they affect the consequences of diabetes: hyperglycemia, hypoglycemia, and microvascular and macrovascular complications. In addition, the new risks introduced by immunosuppression will be reviewed, including infections, cancer, osteoporosis, reproductive function, and the impact of immunosuppression medications on blood pressure, lipids, and glucose tolerance. It is imperative that an endocrinologist remain involved in the care of the pancreas transplant recipient, even when glucose is normal, because of the myriad of issues encountered post transplant, including ongoing management of diabetic complications, prevention of bone loss, and screening for failure of the pancreas graft with reinstitution of treatment when indicated. Although long-term patient and graft survival have improved greatly after pancreas transplant, a multidisciplinary team is needed to maximize long-term quality, as well as quantity, of life for the pancreas transplant recipient.

Improved ultrasound examination of pancreas grafts in type 1 (insulin-dependent) diabetic patients using tissue harmonic imaging

BACKGROUND

Combined kidney/pancreas transplantation is an established therapy for type 1 diabetic patients with end-stage renal disease. Ultrasound examinations are valuable noninvasive methods for postoperative monitoring of transplant recipients. Kidney grafts are easily to detect, whereas pancreas grafts are surrounded or covered by small bowel loops, which makes the examination much more difficult.

PATIENTS AND METHODS

Thirty-three simultaneous pancreas and kidney recipients (SPK) were examined by conventional sonography at 3.4 MHz and THI sonography (pulse inversion, 2.3 MHz) by an investigator experienced in abdominal ultrasound. The images were graded by two "blinded readers" using a scale (1-best image quality, 2-second best, 3-worst) with regard to tissue penetration and detail characterization of the pancreas grafts. The graders were unaware of the sonographic technique, respectively. Statistical evaluation was performed by the Mann-Whitney U test.

RESULTS

In 25 cases (78%) pancreas grafts were detected by conventional sonography. The detection rate was higher using THI sonography, namely 29 cases (91%). Grading for tissue penetration revealed a mean value of 2.05 +/- 0.5 for conventional and 1.94 +/- 0.5 for THI sonography (P =.27). Detail characterization of the pancreas grafts was determined to show a mean value of 2.50 +/- 0.5 for conventional sonography and a significantly better mean value of 1.78 +/- 0.6 for THI sonography (P <.0001).

CONCLUSION

THI sonography improves the detection and the judgment of tissue characteristics of pancreas grafts. Penetration of ultrasound waves is not relevantly decreased by this new technique.

Long-term follow-up of lipid metabolism and rheologic properties after successful pancreas and kidney transplantation

The long-term effect of pancreatic and kidney transplantation (spkt) on blood viscosity, lipid metabolism and skin microcirculation in insulin-dependent diabetes mellitus (IDDM) was studied because impaired rheological properties of blood may play a role in the development of diabetic micro- and macroangiopathy. 46 IDDM-patients (16 f/30 m; 23 +/- 34 y mean duration of diabetes; 60 +/- 14 mos mean follow up period) underwent spkt (Gr.I: n = 28) or solitary kidney (Gr.II: n = 18) transplantation, and were compared with healthy controls (C). Rheological measurements were performed with Mooney-Ewart rotation-viscosimeter determining whole blood viscosity (WBV), at shear rates 1, 5, 10, 20, 50, 100, 200 sec(-1). Triglycerides, total and HDL-, LDL- and VLDL cholesterol and fibrinogen were measured. Microcirculation was estimated by transcutaneous oxygen tension measurement (tcpO2) and laser speckle method, in the forefoot area. Hemoglobin A1 was normalized only in group I (I: 7.2 +/- 0.2%; II: 8.3 +/- 0.3%; C: < 8%). WBV at low shear (1, 5, 10) was increased in both groups, when compared to healthy controls (I: 12.4 +/- 2; 12.5 +/- 1; 6.8 +/- 0.5 mpas; II: 18.7 +/- 2; 13.4 +/- 15; 9.4 +/- 1 mpas; C: 7.5 +/- 0.5; 6.7 +/- 0.3; 5.4 +/- 0.2 mpas; P < 0.05). Plasma fibrinogen was elevated in both groups compared to normals: (I: 384 +/- 19; II: 448 +/- 20; C: 250 +/- 50 mg/dl; P < 0.05). There was a positive influence of spkt on skin microcirculation: tcpO2/prior tx: I: 44 +/- 3; II: 49 +/- 6 mmHg; post tx: I: 59 +/- 4; II: 42 +/- 3 mmHg. Laser speckle prior tx I: 3.3 +/- 0.3; II: 4.7 +/- 0.2 rel. U.; post tx: 3.8 +/- 0.2; II: 4.3 +/- 0.2 rel. U. Patients with progression of angiopathy showed still higher fibrinogen and shear rates (P < 0.05). There was no significant difference for total HDL-, LDL- and VLDL cholesterol. Despite normalization of glucose metabolism and significant improvement of microcirculation in spkt patients, fibrinogen and the shear rates are increased indicating a persisting "individual" vascular risk. It is suggested that an additional hemorheological approach in the treatment posttrransplant might prevent the progression of vascular complications.

Simultaneous pancreas/kidney transplantation--the optimal therapy for type I diabetics with end-stage renal disease in Europe, too?

Contrary to the situation in the USA, the number of pancreatic transplantations declined during the last year in the Eurotransplant region. Whether the high postoperative morbidity and unsatisfactory graft function rates reported by many European centres can be overcome was investigated in a single centre study. In a consecutive series of 80 patients with simultaneous pancreas/kidney transplantations, postoperative morbidity due to graft pancreatitis and recurrent rejections was significant. Both of these complications, however, were treated successfully in the vast majority of patients. Graft thrombosis was almost completely prevented. Excellent function rates of the pancreatic grafts of 88% after 1 year and 83% after 5 years were achieved. Thus, simultaneous pancreas/kidney transplantation can be recommended as the optimal therapy for type I diabetics with end-stage renal disease in Europe, too.

Does glucagon stimulation predict oral glucose tolerance in patients after simultaneous pancreas-kidney transplantation?

BACKGROUND

Exogenous glucagon rapidly stimulates insulin secretion. This test has been used to estimate insulin secretory capacity, which may predict oral glucose tolerance in patients after pancreas transplantation.

METHODS

In 32 pancreas-kidney transplant recipients, in 10 nondiabetic kidney transplant recipients, and in 9 healthy control subjects, a glucagon stimulation test (1 mg i.v.) and a 75-g oral glucose tolerance test were performed with determination of glucose, insulin, and C-peptide profiles.

RESULTS

Of 16 pancreas transplant recipients with the lowest insulin responses after glucagon, 7 had an impaired oral glucose tolerance, in contrast to 1 of 16 with high insulin responses (P=0.037). A low insulin response after glucagon was associated with significantly lower 120-min glucose concentrations (P=0.043) and a lower integrated incremental insulin response after oral glucose (P=0.006).

CONCLUSIONS

In pancreas-kidney transplant recipients, a low insulin response after intravenous glucagon predicts a reduced insulin response after oral glucose and an impaired oral glucose tolerance. This simple test may be helpful in the follow-up of pancreas transplant recipients.

Insulin secretion and sensitivity after simultaneous pancreas-kidney transplantation estimated by continuous infusion of glucose with model assessment

BACKGROUND

Monitoring of insulin secretion and sensitivity after pancreas transplantation remains a practical problem.

METHODS

We introduced the simple structural model, continuous infusion of glucose with model assessment (CIGMA), to obtain insulin secretion and insulin sensitivity estimations after 35 successful simultaneous pancreas-kidney transplantations. Eighteen non-diabetic kidney transplant recipients were used as control group.

RESULTS

The baseline characteristics were equal between the two groups except for higher fasting insulin levels in the pancreas transplant group. After the 1-hr CIGMA glucose load, the pancreas transplant group reached a mean +/- SD blood glucose of 8.2+/-1.7 mmol/L compared with 7.3+/-1.0 mmol/L in the control group (P = 0.05). Concurrent stimulated insulin and C-peptide levels were 48+/-28 mU/L and 2.3+/-0.9 nmol/L in the pancreas transplant group compared with 36+/-21 mU/L and 2.9+/-1.1 nmol/L in the control group (P = 0.1 and P = 0.03, respectively). Both the CIGMA estimation for secretion as well as the CIGMA estimation for sensitivity were lower in pancreas transplant group (P = 0.003 and P = 0.01, respectively). Mean +/- SE coefficients of variation for the model estimations were 15+/-4% for secretion and 17+/-6% for sensitivity.

CONCLUSIONS

We conclude that CIGMA can be used clinically to evaluate carbohydrate metabolism in pancreas-kidney transplant recipients. These patients have a reduction in insulin secretory capacity and evidence of more insulin resistance than non-diabetic kidney transplant recipients.

Effect of venous drainage site on insulin action after pancreas transplantation in the rat--is there insulin resistance and a risk for atherosclerosis?

The aim of the present study was to determine the influence of the venous drainage site on insulin homeostasis and the possible risk for atherosclerosis development after pancreas transplantation. We studied inbred rats that received pancreas transplants with either systemic (STX) or portal (PTX) venous drainage after prior induction of diabetes with streptozotocin and sham-operated controls. The observation period was 6 months. Fasting plasma glucose and insulin levels were similar in all 3 groups, but fasting plasma glucagon levels were elevated in STX (mean +/- SEM, 282+/-35 ng/L) in comparison to PTX rats (119+/-9 ng/L, P < .05), although the difference versus the control group (191+/-31 ng/L) was insignificant. Glucose utilization and hepatic glucose production (HGP), assessed by a dose-response euglycemic-hyperinsulinemic clamp in combination with tritiated glucose infusion, were similar in all 3 groups. The groups were also similar with respect to the molar ratio of plasma C-peptide and insulin during basal steady state and the metabolic clearance rate (MCR) of insulin during the clamp studies, suggesting an unchanged hepatic insulin extraction (HIE) after transplantation with either technique. Factors known to be related to atherosclerosis, ie, blood pressure, intracellular magnesium, and fasting levels of plasma cholesterol, triglycerides, and high-density lipoprotein (HDL) and low-density lipoprotein (LDL) cholesterol, were similar in all 3 groups. Light microscopy of the aorta showed a slightly thicker intima in STX rats (24.3+/-0.5 microm, P < .05) versus PTX rats (21.4+/-0.7 microm) and control (21.4+/-0.6 microm); however, atherosclerosis-like lesions were absent in all 3 groups. In conclusion, in a rat model with streptozotocin-diabetes and pancreas transplantation but no need for immunosuppression, both systemic and portal venous drainage avoid peripheral and hepatic insulin resistance; also, there is no increased risk for atherosclerosis.

Pancreatic and islet transplantation

Diabetes mellitus is the most devastating chronic disease of all time. This review discusses the current therapies for type 1 diabetes that are predicated on the restoration of insulin secretion by transplantation. Recent developments in vascularized pancreas transplantation have led to a dramatic increase in the number of these procedures performed worldwide, with over 10,000 cases reported currently to the International Pancreas Transplant Registry. Although the procedure contributes to a significant improvement in quality of life, compared with traditional insulin therapy, it still suffers from a number of shortcomings, including a persistently high postoperative morbidity rate and the requirement of long-term immunosuppression. Islet transplantation is therefore being pursued actively as an equally efficient means of restoring normoglycemia, but without the attendant morbidity of the whole-organ procedure, and hopefully with a significantly reduced need for immunosuppression.

Clinical islet cell transplantation. Are we there yet?

Diabetes mellitus is perhaps the most devastating chronic disease of all time. A brief history of the evolution of treatment modalities is provided, culminating in the rationale for the physiologic replacement of a functioning beta-cell mass by transplantation. Vascularized pancreas transplantation is discussed briefly as an introduction to the transplantation of the isolated islet. A detailed review of the current state of human islet transplantation for the cure of diabetes is then described. Finally, areas for future development are highlighted.

Basal serum pancreatic polypeptide is dependent on age and gender in an adult population

This study is the first epidemiologically based study of basal levels of serum pancreatic polypeptide (s-PP). The basal level of serum PP has become a field of interest mainly due to the role of PP as an endocrine tumour marker, and as a marker of pancreatic neuroendocrine function after pancreas transplantation and in the case of diabetic autonomic neuropathy. The study population consisted of primarily Caucasian adults representative of a general population living around Copenhagen. Serum pancreatic polypeptide was measured in random serum samples from fasting persons (n = 623), aged 25-64 y, using a monospecific radioimmunoassay. Fasting serum pancreatic polypeptide depended on age and gender. The results demonstrated that fasting pancreatic polypeptide levels increase exponentially with age. Fitted separately for each sex, basal serum pancreatic polypeptide was found to increase by approximately 3% per year of age. Males had higher concentrations of pancreatic polypeptide in serum compared to age-matched females. Normal range and 95% reference intervals are given. The lower limit for the reference interval of the normal range was close to detection limit. We conclude that discrepancies among earlier reports on the fasting levels of serum pancreatic polypeptide are most likely due to lack of adjustment for age and gender. Thus, variation due to age and gender should be considered in evaluating fasting levels of serum pancreatic polypeptide. Whether similar considerations are important when evaluating stimulated serum pancreatic polypeptide levels remains to be elucidated.

Pancreas and islet transplantation. Challenges for the twenty-first century

This article reviews both pancreas and islet transplantation in detail. The history of each procedure, the effects of these therapies on glucose metabolism, glucose counterregulation, and islet cell secretory function, as well as the challenges that result from each procedure are considered.

The effect of venous drainage on glucose homeostasis after experimental pancreas transplantation

In this canine study, glucose homeostasis after clinical pancreas transplantation is complex, with the relative effect of systemic versus portal delivery of insulin remaining unresolved. Thirty-two pancreatectomized dogs received either systemic venous drainage (SVD) with bladder exocrine drainage (n = 16), or portal venous drainage (PVD) with gastric exocrine drainage (n = 16). Cyclosporine (CsA) based immunosuppression was commenced on day -7. The effect of immunosuppression was a significant increase in fasting blood glucose (FBGL) (P = 0.002), fasting insulin (P = 0.024), AUC for insulin (P = 0.009), and K values decreased (P = 0.009). FBGL and K values remained abnormal after transplantation with no significant difference seen between SVD and PVD. However, fasting insulin became significantly lower after PVD and AUC insulin fell in both groups. CsA levels fell in both groups after transplantation, mirroring the fall in AUC insulin, and implicating CsA as a major cause of peripheral resistance to insulin. In conclusion, PVD did not demonstrate a significant advantage over SVD in handling an intravenous glucose challenge. The need for pancreatectomy in large animals may make them an unsatisfactory experimental model to evaluate the glucoregulatory effects of pancreas allotransplantation.

Clinical determinants of glucose homeostasis after pancreas transplantation

Although successful simultaneous pancreas and kidney transplantation (SPK) achieves normoglycemia in the majority of diabetic recipients with end-stage renal disease, little is known about the factors that influence long-term endocrine function. In this prospective study of 48 bladder-drained SPK patients, 209 oral glucose tolerance tests were performed between 3 months and 6 years after transplantation. Normal fasting glucose levels and systemic hyperinsulinemia were stable for up to 6 years after SPK. Multivariate analysis revealed that increased area-under-curve (AUC) levels of C-peptide 3 months after transplantation were predicted by short surgical pancreas anastomosis time, greater recipient body weight, and total HLA mismatch score. Episodes of acute pancreas rejection were not associated with reduced allograft insulin output in the long term. Insulin output, stimulated by oral glucose tolerance tests and assessed by the ratio of AUC insulin to AUC glucose, fell gradually after transplantation and was decreased by an elevated serum calcium level and high cyclosporine dose. The ratio of fasting insulin to glucose, which acts as a marker of peripheral insulin resistance, fell with time after transplantation and was increased by greater body weight, higher prednisolone dose, and lower cyclosporine dose. The inhibitory effect of cyclosporine on both fasting and postprandial insulin output was, however, minor when quantified by multivariate analysis. Endocrine function of the transplanted pancreas was not correlated with its exocrine function measured by urinary amylase excretion, nor was there a correlation with change in renal function measured by isotopic glomerular filtration rate. In summary, simultaneous pancreas and kidney transplantation leads to excellent long-term glucose homeostasis maintained at the expense of systemic hyperinsulinemia. The key factors adversely affecting peripheral resistance in SPK were corticosteroid therapy, body weight, and time after transplantation. The susceptibility of islets to ischemia-reperfusion injury, as quantitated by surgical anastomosis time, may have implications for islet transplantation programs, as may the relative resistance of islets to allograft rejection. Glucose homeostasis after SPK, while remaining abnormal, may be used as the standard against which islet transplantation must be measured.

Determinants of a normal (versus impaired) oral glucose tolerance after combined pancreas-kidney transplantation in IDDM patients

After successful pancreas transplantation, insulin-dependent diabetic patients are characterized by a normal or at worst impaired oral glucose tolerance (World Health Organisation criteria). It is not known which pathophysiological mechanisms cause the difference between normal and impaired oral glucose tolerance. Therefore, we studied 41 patients after successful combined pancreas-kidney transplantation using stimulation in the fasting state with oral glucose (75 g), intravenous glucose (0.33 g/kg) and glucagon bolus injection (1 mg i.v.). Glucose (glucose oxidase), insulin and C-peptide (immunoassay) were measured. Repeated-measures analysis of variance and multiple regression analysis were used to analyse the results which showed: 28 patients had a normal, and 13 patients had an impaired oral glucose tolerance. Impaired oral glucose tolerance was associated with a greatly reduced early phase insulin secretory response (insulin p < 0.0001; C-peptide p = 0.037). Age (p = 0.65), body mass index (p = 0.94), immunosuppressive therapy (cyclosporin A p = 0.84; predniso(lo)ne p = 0.91; azathioprine p = 0.60) and additional clinical parameters were not different. Reduced insulin secretory responses in patients with impaired oral glucose tolerance were also found with intravenous glucose or glucagon stimulations. Exocrine secretion (alpha-amylase in 24-h urine collections) also demonstrated reduced pancreatic function in these patients (-46%; p = 0.04). Multiple regression analysis showed a significant correlation of 120-min glucose with ischaemia time (p = 0.003) and the number of HLA-DR mismatches (p = 0.026), but not with HLA-AB-mismatches (p = 0.084). In conclusion, the pathophysiological basis of impaired oral glucose tolerance after pancreas transplantation is a reduced insulin secretory capacity. Transplant damage is most likely caused by perioperative influences (ischaemia) and by the extent of rejection damage related, for example, to DR-mis-matches.

[Benefits and limitations of pancreas transplantation in insulin-dependent diabetics: a study apropos of 26 patients]

From November 1990 to March 1995, 26 simultaneous pancreas-kidney (SPK) transplants were carried out. The recipients were uremic type I diabetic patients. After the first year of transplantation, patient survival was 96% and pancreas and kidney survival was 69% and 84%, respectively. The pancreas transplant failure was due to veinous thrombosis (two cases), and to graft rejection (71%). The most common urologic complications of bladder drainage were urethritis (61%), bicarbonate loss (42%) and urinary tract infections (100%). Fasting blood glucose (0.91 +/- 0.1 g/L), hemoglobin A1C (5.3 +/- 0.4%) and lipidic profile were found to be normal among diabetic recipients whose grafts had been functioning for 1 year. The insulin secretion of type I diabetic patients with SPK transplants (n = 13), and six non diabetic patients with kidney transplants was assessed by oral glucose tolerance tests. Only the patients with SPK transplants presented late hyperinsulinemia at 120 minutes. The quality of life for both type I diabetic patients after SPK transplants and diabetics treated by insulinotherapy (n = 6), was studied. After transplantation, the quality of life improved only because of insulin independence. In spite of chirurgical and urologic complications, pancreas transplantation in type I diabetic patients improves both metabolic control and quality of life.

Cephalic-phase insulin and glucagon release in normal subjects and in patients receiving pancreas transplantation

The aim of the study was to evaluate whether the cephalic phase of insulin release is still present in patients submitted to simultaneous kidney and pancreas transplantation. Subjects were five kidney-pancreas-transplanted patients (group P) and five control (group C). The experimental protocol lasted 30 minutes, and blood samples were collected at 1-minute intervals. After a 20-minute period of steady-state fasting (premeal period), subjects received a palatable standard meal (pizza). Samples were collected over the subsequent 10 minutes (meal period). No evidence of an increase in serum free insulin, serum C-peptide, and plasma glucagon during food ingestion was observed in group P whereas the test was effective in eliciting cephalic-phase insulin and glucagon release in group C. Gastric inhibitory polypeptide and somatostatin did not show any variation during the test in both groups. In conclusion, the absence of cephalic-phase insulin and glucagon release in group P could be explained by denervation of the grafted pancreas. This early alteration could contribute to the impairment in glucose tolerance frequently observed in successfully pancreas-transplanted patients.

Patient perceptions of benefits and concerns following pancreas transplantation

The purpose of this study was to assess patient perceptions of the impact of pancreas transplantation on various aspects of life, as well as perceptions of the benefits of and concerns with the procedure. All surviving adult patients who had received a pancreas transplant at a midwestern hospital and were at least 1 year posttransplant at the time of the study (N = 138) were sent a self-report questionnaire that included demographic data, questions about life satisfaction, quality of life, symptoms, and health impact. Patients with pancreas graft function reported less pain with healthcare treatment, fewer episodes of feeling physically ill, fewer dietary restrictions, less interference with family life, fewer health limitations in interpersonal relationships and leisure activities, and feeling good about themselves compared with those without graft function. A majority of patients with functioning grafts cited the following benefits: freedom from insulin reactions, normal blood sugars, freedom from insulin injections, freedom from a specialized diet, decreased chance of amputation, feeling better physically, more feelings of hope for the future, and more freedom and control over life. Major concerns posttransplant included side effects and the expense of immunosuppressive medications.

Sequential evaluation of islet cell responses to glucose in the transplanted pancreas in humans

We evaluated the hormonal and metabolic responses of denervated pancreas allografts in nine volunteers 3 to 12 months after the transplant (initial) and again 1 year later (follow-up). Eight of the patients received simultaneous pancreas-kidney transplants. The glucose clamp technique was used to create a square wave of hyperglycemia 5.5 mmol/L above the basal glucose level for 2 hours. A biphasic insulin response was evident in each subject, both initially and at follow-up. The initial plasma insulin response was fourfold higher in patients with pancreas-kidney transplants than in normal volunteers. However, the plasma insulin response of the patients with pancreas-kidney transplants at the follow-up study was more similar to that of the normal controls. The plasma glucagon levels were elevated in follow-up clamp studies. Hepatic glucose production and glucose disposal were similar in both studies. At the follow-up examination only, GLUT4, the major insulin-sensitive glucose transporter, was measured in muscle homogenates by immunoblotting. GLUT4 levels in the patients with pancreas-kidney transplants were only 55% as abundant as in normal volunteers. This may be due, in part, to immunosuppressive therapy or to persistent, albeit reduced, levels of hyperinsulinemia even 2 years after transplantation. We concluded that, despite systemic drainage of the pancreas and immunosuppressive therapy, pancreatic insulin secretion, peripheral insulin levels, and muscle insulin responsiveness are restored toward normal levels approximately 2 years after the transplant.

Cross-sectional study of peripheral microcirculation in diabetic patients with microangiopathy: influence of pancreatic and kidney transplantation

Diabetic vascular lesions and peripheral autonomic neuropathy are both closely linked to long-term metabolic control of diabetes. Transcutaneous oxygen tension (PtcO2) measurements were made to elucidate whether autonomic neuropathy disturbs the cutaneous microcirculatory blood flow, and whether long-term glucose normalization ameliorates such impairment. Twenty-eight type 1 (insulin-dependent) diabetic patients in whom clinically significant macroangiopathy had been excluded by angiography were studied, subdivided into group A (n = 14; before simultaneous pancreas/kidney transplantation (SPKT); mean age 35 years, range 22-51 years; mean duration of diabetes 24 years, (range 15-32) years and group B (n = 14; mean 31 months, range 2-101 months, after successful SPKT; mean age 35 years, range 19-56 years; mean duration of diabetes 22 years, range 14-29 years). On addition there was a group (group C) of age- and sex-matched healthy control subjects (n = 14; mean age 35 years, range 23-62 years). PtcO2 measurements included basal recordings at 44 degrees C on the leg and the foot, functional recordings at 44 degrees C after arterial occlusion of the limb for 4 min, measurements during breathing 5 l oxygen per minute and finally while standing up (stand up dP20/dt). All subjects underwent extensive cardiac autonomic testing. In this cross-sectional study the recordings of basal values and of the functional parameters after arterial occlusion and during breathing oxygen did not differ significantly between groups A, B and C.(ABSTRACT TRUNCATED AT 250 WORDS)

Pancreas and islet transplantation in man

The results of pancreas transplantation have greatly improved, the overall patient and graft 1-year survival rates now being 89 and 62%, respectively. A technically successful graft ensures a near-normal glucose metabolism in most cases, and improves the patient's quality of life. However, pancreas transplantation is not a life-saving procedure and because of the necessary permanent immunosuppression it is usually performed in patients in whom a kidney transplant is needed or has been previously established. In such patients the other diabetic chronic complications are often advanced and limit the potential benefit of pancreas transplantation, but it seems premature to extend the indications to early stage diabetes. Islet transplantation has many potential advantages, mainly the possibilities of immune alteration and immune protection of the transplant that could allow transplantation to be performed without immunosuppression and the use of xenogenic tissue. Major limiting factors are the high numbers of islets necessary to ensure insulin independence and the low yield of islet isolation from adult pancreas. Encouraging, albeit preliminary results have been recently reported in man.