Postprandial glucose and HbA1c are associated with severity of obstructive sleep apnoea in non-diabetic obese subjects

INTRODUCTION

Obstructive sleep apnoea (OSA) is an underdiagnosed condition frequently associated with glycaemic control impairment in patients with type 2 diabetes.

AIM

To assess the relationship between glycometabolic parameters and OSA in obese non-diabetic subjects.

METHODS

Ninety consecutive subjects (mean age 44.9 ± 12 years, mean BMI 42.1 ± 9 kg/m²) underwent polysomnography and a 2-h oral glucose tolerance test (OGTT).

RESULTS

OSA was identified in 75% of subjects, with a higher prevalence of males compared to the group of subjects without OSA (62% vs 32%, p = 0.02). Patients with OSA had comparable BMI (42.8 kg/m² vs 39.4 kg/m²), a higher average HbA1c (5.8% vs 5.4%, p < 0.001), plasma glucose at 120 min during OGTT (2 h-PG; 123 mg/dl vs 97 mg/dl, p = 0.009) and diastolic blood pressure (81.1 mmHg vs 76.2 mmHg, p = 0.046) than obese subjects without OSA. HbA1c and 2 h-PG were found to be correlated with the apnoea-hypopnoea index (AHI; r = 0.35 and r = 0.42, respectively) and with percent of sleep time with oxyhaemoglobin saturation < 90% (ST90; r = 0.44 and r = 0.39, respectively). Further, in a linear regression model, ST90 and AHI were found to be the main determinants of 2 h-PG (β = 0.81, p < 0.01 and β = 0.75, p = 0.02, respectively) after controlling for age, sex, waist circumference, physical activity, and C-reactive protein. Similarly, ST90 and AHI persisted as independent determinants of HbA1c (β = 0.01, p = 0.01 and β = 0.01, p = 0.01, respectively).

CONCLUSION

Beyond the traditional clinical parameters, the presence of a normal-high value of 2 h-PG and HbA1c should raise suspicion of the presence of OSA in obese subjects.

Prolonged Siberian heat of 2020 almost impossible without human influence

Over the first half of 2020, Siberia experienced the warmest period from January to June since records began and on the 20th of June the weather station at Verkhoyansk reported 38 °C, the highest daily maximum temperature recorded north of the Arctic Circle. We present a multi-model, multi-method analysis on how anthropogenic climate change affected the probability of these events occurring using both observational datasets and a large collection of climate models, including state-of-the-art higher-resolution simulations designed for attribution and many from the latest generation of coupled ocean-atmosphere models, CMIP6. Conscious that the impacts of heatwaves can span large differences in spatial and temporal scales, we focus on two measures of the extreme Siberian heat of 2020: January to June mean temperatures over a large Siberian region and maximum daily temperatures in the vicinity of the town of Verkhoyansk. We show that human-induced climate change has dramatically increased the probability of occurrence and magnitude of extremes in both of these (with lower confidence for the probability for Verkhoyansk) and that without human influence the temperatures widely experienced in Siberia in the first half of 2020 would have been practically impossible.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s10584-021-03052-w.

Pacemaker lead perforation of the right ventricle associated with Moraxella phenylpyruvica infection in a dog

CASE DESCRIPTION

A 13-year-old neutered male Border Collie was presented with acute onset syncope, weakness and anorexia 10 months after transvenous pacemaker implantation. The patient was laterally recumbent, bradycardic (36 beats/min) and febrile (40.7°C) on presentation. An electrocardiogram (ECG) revealed recurrence of third-degree atrioventricular block with a ventricular escape rhythm. Fluoroscopy identified migration of the pacemaker tip through the apex of the right ventricle. Echocardiography failed to reveal any evidence of pericardial effusion or cardiac tamponade. Full postmortem was performed after euthanasia. The pacemaker lead had perforated the apex of the right ventricle and lodged in the right pleural space. Culture of blood (taken antemortem), pericardial sac, right ventricular wall (surrounding pacemaker lead), pacemaker lead tip and pericardial fluid revealed a pure growth of Moraxella phenylpyruvica.

CONCLUSION

Bacteraemia associated with M. phenylpyruvica has never been reported in the dog, but sporadic cases are reported in humans. Infection could have resulted from either pre-existing myocarditis or opportunistic infection and bacteraemia post pacemaker implantation. Evaluation of the pacemaker function at regular intervals would allow early detection of poor pacemaker-to-myocardium contact, which would prompt further investigation of pacemaker lead abnormalities such as perforation.

Comparing regional precipitation and temperature extremes in climate model and reanalysis products

A growing field of research aims to characterise the contribution of anthropogenic emissions to the likelihood of extreme weather and climate events. These analyses can be sensitive to the shapes of the tails of simulated distributions. If tails are found to be unrealistically short or long, the anthropogenic signal emerges more or less clearly, respectively, from the noise of possible weather. Here we compare the chance of daily land-surface precipitation and near-surface temperature extremes generated by three Atmospheric Global Climate Models typically used for event attribution, with distributions from six reanalysis products. The likelihoods of extremes are compared for area-averages over grid cell and regional sized spatial domains. Results suggest a bias favouring overly strong attribution estimates for hot and cold events over many regions of Africa and Australia, and a bias favouring overly weak attribution estimates over regions of North America and Asia. For rainfall, results are more sensitive to geographic location. Although the three models show similar results over many regions, they do disagree over others. Equally, results highlight the discrepancy amongst reanalyses products. This emphasises the importance of using multiple reanalysis and/or observation products, as well as multiple models in event attribution studies.

Transition from pediatric to adult care. eight years after the transition from pediatric to adult diabetes care: metabolic control, complications and associated diseases

BACKGROUND

Transition from pediatric to adult care is a critical process in the life of patients with diabetes.

AIM

Primary aim of the study was to compare the metabolic control between pediatric care and adult care at least 5 years in a group of patients with type 1 diabetes mellitus (T1DM). Secondary aim was to evaluate the presence of complications, associated diseases and psychological-psychiatric disorders.

SUBJECTS AND METHODS

We obtained data from 73 % (69/94) patients (current mean age 34 years) transferred to local adult centers between 1985 and 2005 at a mean age of 23.8 years. Data were collected for HbA1c, diabetic complications and associated diseases.

RESULTS

Mean HbA1c did not change during the pediatric, transition and adult period [8.4 ± 1.8 % (68 ± 18 mmol/mol), 8.3 ± 1.4 % (67 ± 15 mmol/mol) and 8.4 ± 1.3 % (68 ± 14 mmol/mol), respectively]. 13 patients dropped out, after 2-12 years since transition, and their HbA1c mean value at transition was 10.4 %. After a mean of 25.9 years of disease, 35/69 patients (50.7 %) showed retinopathy, and 12/69 patients (17.3 %) nephropathy. Thyroid diseases were the most frequent associated diseases (18.3 %), followed by depression (11.2 %) and benign neoplasms (9.8 %). Drug or alcohol addictions were present in four cases (5.6 %).

CONCLUSIONS

After a mean follow-up of 8 years metabolic control after transition did not change significantly in patients constantly attending to adult care centre. Patients with diabetes onset between 20 and 40 years ago were free from complications in 50 % of cases when considering retinopathy and in more than 80 % considering nephropathy. Thyroid problems were the most common associated diseases. Poor metabolic control at transition is associated with higher risk of drop-out and psychosocial morbidity.

Enhanced pressor responsiveness to norepinephrine in type II diabetes. Effect of ACE inhibition

OBJECTIVE

To evaluate the effect of angiotensin-converting enzyme (ACE) inhibition on the pressor responsiveness to norepinephrine in type II diabetes.

RESEARCH DESIGN AND METHODS

Eight normotensive subjects, eight mild-to-moderate hypertensive type II diabetic patients, and eight nondiabetic patients with essential hypertension were studied before and after 4 weeks of being administered enalapril. The pressor response to norepinephrine was assessed by infusing the hormone in an antecubital vein at incremental doses of 30 ng.kg-1.min-1 for periods of 5 min until reaching an increase of 20 +/- 2 mmHg in mean arterial pressure (MAP) measured by an automatic device at 1-min intervals. An effective dosage of norepinephrine that increased MAP by 20 mmHg (EDNE 20) was thereafter calculated. Before and during the last minute of norepinephrine infusion at maximum dosage, a venous blood sample was drawn to determine plasma renin activity (PRA), aldosterone, and norepinephrine levels.

RESULTS

In the three groups of patients, blood pressure and aldosterone were reduced while PRA was raised following ACE inhibition. Basal and maximum postinfusion levels of norepinephrine were not modified by enalapril. The EDNE 20 was basally lower in diabetic patients and remained unchanged after ACE inhibition, contrary to that observed in nondiabetic patients with essential hypertension.

CONCLUSIONS

Both normotensive and hypertensive type II diabetic patients have an increased pressor responsiveness to norepinephrine that is not modified by therapeutic doses of enalapril, contrary to what is observed in nondiabetic patients with essential hypertension.

[Diabetic nephropathy and pregnancy]

During pregnancy, the kidneys of diabetic women undergo an elevated functional load which occurs to a greater extent if nephropathy coexists. Functional abnormalities, such as reduction of glomerular filtration rate, increase of creatinine and proteinuria, which can be observed in about 1/3 of the cases, regress or stabilize progressing only in a limited number of patients. Arterial hypertension and poor metabolic control seem to be the factors most closely correlated to the loss of renal function. Diabetic nephropathy determines an increased risk of maternal and fetal complications to be seen more frequently in women with more compromised renal function at conception, and with poor metabolic control during pregnancy. From here stems the importance of good metabolic control right from conception. Moderate physical exercise, a caloric intake of 25-35 kcal/kg/day and slight reduction of protein diet content are also advisable. Monitoring includes periodical evaluation of glycated haemoglobin, creatinine, uric acid, creatinine clearance and albuminuria not only during pregnancy but also after months or years following delivery. Arterial pressure must be monitored avoiding aggressive antihypertensive treatment. The most suitable drugs are considered alfa-methyldopa, clonidine, hydralazine and prazosine.

Angiographic evaluation of the anatomic pattern of arterial obstructions in diabetic patients with critical limb ischaemia

OBJECTIVE

The present study was undertaken to evaluate, by means of angiography, the anatomic pattern of arterial obstructions in the lower extremities of diabetic patients presenting with critical limb ischaemia. We particularly examined the differences in involvement of the foot arteries between patients with and without diabetes.

PATIENTS AND METHODS

A group of 150 patients with limb-threatening ischaemia, manifested by rest pain and/or non-healing ischaemic ulcers or gangrene, underwent angiologic evaluation in prevision of vascular surgery. The patients, of whom 89 were suffering from diabetes, were examined by means of digital subtraction angiography using the Seldinger technique. In each patient, details of arterial tree were obtained from the aortoiliac to the foot arteries and the site and the extent of obstructions were determined blindly with the radiologist unaware of the patient's history of diabetes.

RESULTS

Diabetic patients showed significantly more obstructions in the infrapopliteal arteries when compared to the patients without diabetes who had more pronounced involvement of aortoiliac and femoropopliteal arteries. Diabetic patients, moreover, showed a higher prevalence of obstruction in posterior tibial, peroneal and plantar arteries than the non-diabetics. At the time of presentation, the age of patients did not differ between the two groups but diabetic patients had more frequent ischaemic ulcers or gangrene and less rest pain than the non-diabetics.

CONCLUSIONS

Our study confirms earlier reports carried out with non-angiographic methods indicating more frequent involvement of calf arteries in diabetic patients but disagrees with those which report that patients with diabetes have less occlusive disease in foot arteries.

Low-dose angiotensin converting enzyme inhibitors: effect on renal function in normo- and hypertensive type 1 diabetic patients

OBJECTIVES

To investigate the effect of low doses of the angiotensin converting enzyme inhibitor enalapril on renal haemodynamics and albuminuria in normotensive and hypertensive type 1 (insulin-dependent) diabetic patients with incipient or overt nephropathy.

METHODS

Twenty-two type 1 (insulin-dependent) diabetic patients with persistent microalbuminuria or macroalbuminuria and normal serum creatinine were studied. Of all patients, 16 males and 6 females, age 45 +/- 13 years, diabetes duration 19 +/- 11 years, insulin dose 38 +/- 11 U/day, 10 were normotensive and 12 were hypertensive. After 3 months of run-in period the patients were assigned to treatment with 5 mg or 10 mg enalapril based on the presence of normotension or hypertension respectively. Before and after 6 months of treatment, renal function was assessed by evaluation of glomerular filtration rate (99m Tc-DTPA), renal plasma flow (131-I iodohippurate), filtration fraction and renal vascular resistance. Mean arterial pressure, albumin excretion rate, urinary urea excretion and glycated haemoglobin were also determined.

RESULTS

Administration of enalapril resulted in both groups of patients in a significant fall in mean arterial pressure, albumin excretion rate, glomerular filtration rate, filtration fraction, and renal vascular resistance. Decreasing albumin excretion did not correlate with a drop in systemic blood pressure or filtration fraction. No significant variations were observed in renal plasma flow, in urinary urea excretion or in glycated haemoglobin.

CONCLUSIONS

Our results suggest that low doses of enalapril are effective in influencing renal haemodynamics and reducing urinary albumin excretion in both normotensive and hypertensive type 1 (insulin-dependent) diabetic patients with incipient or overt nephropathy. The lowering effect of the angiotensin converting enzyme inhibitor on albuminuria seems to be independent of the action on systemic blood pressure and renal haemodynamic changes.

ACE inhibition in diabetic patients: effect on pressor responsiveness to noradrenaline

The pressor responsiveness to noradrenaline was assessed before and after four weeks of treatment with enalapril (20 mg/day) in eight mild-to-moderate essential hypertensives, in eight normotensive type II diabetics and in eight mild-to-moderate hypertensive type II diabetic patients. The ACE inhibitor interfered to the same extent with the renin-angiotensin system and did not alter noradrenaline kinetics in the three groups of patients, but significantly reduced the arterial responsiveness only in non-diabetic subjects. It is suggested that factors, such as an exaggerated sodium retention, might determine the lack of effect of enalapril in diabetic patients.

Intra-arterial urokinase infusion in diabetic patients with rapidly progressive ischemic foot lesions

OBJECTIVE

The effectiveness of local intra-arterial thrombolysis by urokinase was evaluated in eight non-insulin-dependent diabetic patients with angiographic evidence of infrapopliteal occlusive disease and rapidly progressive foot lesions.

RESEARCH DESIGN AND METHODS

With an electric peristaltic pump, urokinase was infused for 96 h by a 5-6 F catheter introduced into the femoral artery and placed immediately above the occluded infrapopliteal arteries. After baseline, angiography was repeated at 24- to 48-h intervals and at conclusion of the treatment.

RESULTS

Six patients showed immediate improvement of clinical symptoms. Angiography revealed the reestablishment of blood flow in collateral vessels of the leg and foot in the dorsal pedal artery in three patients and in the plantar arch in two. Recanalization of the major arteries of the trifurcation was not achieved. After 12 mo of follow-up, all limbs were salvaged, although four patients required vascular reconstruction to further improve foot perfusion and complete healing.

CONCLUSIONS

Intra-arterial urokinase, which opens collateral and smaller vessels of the leg and foot in patients with diabetes, may be effective in improving blood flow in lower extremities and in making the patient a better candidate for vascular surgery.

The effect of ace inhibition on peripheral hemodynamics in normotensive and hypertensive patients with type II diabetes

The effect of treatment with enalapril (10 days at 10 mg/d followed by 4 weeks at 20 mg/d) on forearm hemodynamics was assessed in eight normotensive patients and eight patients with hypertension affected by Type II diabetes as well as in eight patients with essential hypertension and normal glucose tolerance. The ACE inhibitor decreased regional vascular resistances and increased the maximum arteriolar-vasodilating capacity and venous distensibility in the three groups of patients. Thus, this study shows that ACE inhibition by enalapril improves regional hemodynamics in patients with Type II diabetes.

A screening test for microalbuminuria in type 1 (insulin-dependent) diabetes

In this study we evaluated the acceptability of using the first morning urine albumin concentration (FMAC) and the first morning urine albumin/creatinine (FMA/C) ratio as an indirect estimation of timed albumin excretion in order to screen for microalbuminuria in a large diabetic population. Urinary albumin excretion rate (AER) was determined in samples from 4-h urine collection in 99 type 1 diabetic patients aged 30 +/- 10 years with a mean duration of diabetes of 15 +/- 8 years. The results of timed albumin excretion were successively compared with single-void first morning samples. On the basis of AER, 46 patients were normoalbuminuric (AER less than 20 micrograms/min), 28 microalbuminuric (AER 20-200 micrograms/min), and 25 proteinuric (AER greater than 200 micrograms/min). The relationship of 4-h AER to FMAC and FMA/C ratio was highly significant (r = 0.96 and r = 0.98 respectively). High sensitivity and specificity were found when cut-offs of 20 micrograms/ml and 2.5 mg/mmol were selected for albumin concentration and albumin/creatinine ratio respectively to discriminate between normal and elevated albuminuria. It is concluded that the measurements of albumin concentration and albumin/creatinine ratio in first morning urine samples are highly representative of 4-h timed albumin excretion. Because of their sensitivity, specificity and simplicity to perform, the tests proposed might be used in routine diabetic care and as a screening test for microalbuminuria in type 1 (insulin-dependent) diabetic patients. The not negligible day-to-day variability in albumin excretion confirms the need of several measurements to establish the presence of abnormal levels of albuminuria above all in patients with borderline values and/or clinically unstable metabolic control.

Oesophageal transit time and cardiovascular autonomic neuropathy in type 1 (insulin-dependent) diabetes mellitus

Oesophageal computerized dynamic scintigraphy with 99 mTc was used to evaluate oesophageal motility in type 1 (insulin-dependent) diabetic patients without upper gastrointestinal symptoms. Twenty-nine patients, 10 women and 19 men, mean age 38 +/- 12 yr (range 17-55), mean duration of diabetes 15 +/- 8 yr (range 3-30) and 15 controls were studied. Background or proliferative retinopathy was found in 72.4% of patients, incipient or clinical nephropathy in 48.3% and peripheral neuropathy in 62% of them. In all, oesophagitis and/or other disorders of the upper gastrointestinal tract were excluded by barium studies and endoscopy. Oesophagus scintigraphy with 99 mTc sulphur colloid was performed in each subject after fasting for at least 3 hr in the supine position and repeated after few minutes to assess its reproductivity. The rate of passage of the fluid bolus through oesophagus was analyzed by computer and oesophageal transit time (OTT) for the whole oesophagus was measured by time-activity curves. All diabetic patients were screened for autonomic cardiovascular function by standard tests and, on the base of results, assigned to cardiovascular autonomic neuropathy positive (CVAN-positive) or to cardiovascular autonomic neuropathy negative (CVAN-negative) group. Abnormal oesophageal motility (OTT less than 14 sec as mean +/- 2 SD of controls) was found in 68.7% of CVAN-positive and in 15.4% of CVAN-negative patients (p less than 0.05). CVAN-positive patients resulted older and had significantly longer duration of diabetes than other patients. Furthermore, they showed higher frequency of severe retinopathy, nephropathy, peripheral neuropathy and prolonged OTT compared with CVAN-negative patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Hyperglycemic effect of sucrose ingestion in IDDM patients controlled by artificial pancreas

The hyperglycemic effect of 28 g sucrose, taken during a mixed meal, was studied in six insulin-dependent diabetes mellitus (IDDM) patients controlled by artificial pancreas. On 2 consecutive days the patients were given, in random order, two Italian meals containing macaroni, bread, meat, vegetables, fruit, olive oil, and an eggnog made with sucrose (meal A) or saccharin (meal B). The two meals were isocaloric and contained equal amounts of carbohydrates. The feedback control on blood glucose continued for 180 min after the meals. Plasma glucose levels and insulin infusion rates delivered by the artificial pancreas after the two test meals did not show any significant differences regarding basal and peak values, peak times, and areas under the curves. A modest amount of sucrose, taken during a mixed meal, does not produce a hyperglycemic effect higher than an equal amount of complex carbohydrates in IDDM patients controlled by artificial pancreas. The same may be expected in well-controlled IDDM patients in conventional therapy because a correlation exists between insulin requirement for conventional therapy and insulin delivered during glucose-controlled insulin infusion.

Possible effectiveness of plasmapheresis and immunosuppressive therapy in reversing subcutaneous insulin resistance: a case report

Severe resistance to subcutaneous insulin with normal sensitivity to intravenous insulin developed in a 39 year old woman affected by type 1 diabetes mellitus. The patient had been treated for ten months with continuous intravenous or intraperitoneal insulin before undergoing pancreatic transplantation. After surgery repeated plasmapheresis were performed and immunosuppressive therapy was undertaken. When studied again, one month after surgery, the patient showed normal sensitivity to subcutaneous insulin. Our data suggest that plasmapheresis and/or immunosuppressive treatment could have played a role in reversing insulin resistance.

Reduced albuminuria after dietary protein restriction in insulin-dependent diabetic patients with clinical nephropathy

Recent clinical investigations have demonstrated that an early restriction of dietary protein intake may reduce the rate of progression of chronic renal failure in humans. In this study the effects of a restricted-protein diet on kidney function in type I diabetic patients with clinical nephropathy were evaluated. Sixteen patients (9 men, 7 women) with mean age 37.1 +/- 9.8 yr, mean duration of diabetes 17.7 +/- 6.6 yr, proteinuria greater than 0.5 g/24 h, and serum creatinine concentration of 0.7-1.9 mg/dl were studied. Patients were randomly divided into two groups. The low-protein diet (LPD) group comprised seven patients who were kept for 4.5 +/- 1 mo on a diet containing 0.71 +/- 0.12 g X kg-1 X day-1 protein. The normal-protein diet (NPD) group comprised nine patients as controls maintained for 11.7 +/- 7 mo on their usual diabetic diet containing 1.44 +/- 0.12 g X kg-1 X day-1 protein. All patients were studied every 1-2 mo. Metabolic control was assessed by evaluation of 5-8 blood glucose determinations/day and by glycosylated hemoglobin, whereas renal function was evaluated by albumin, IgG and beta 2-microglobulin urinary excretion rates, serum creatinine concentration, and creatinine clearance. At each visit, serum concentrations of total protein, albumin, phosphate, calcium, and electrolytes and weight and blood pressure were also measured. A significant reduction (434 +/- 244 to 205 +/- 212 micrograms/min, mean +/- SD) in albumin excretion rate was found in all LPD patients after dietary protein restriction, with a significant reincrease (689 +/- 201 micrograms/min) in the same patients several months after interruption of diet.(ABSTRACT TRUNCATED AT 250 WORDS)

Investigation of insulin resistance associated with Werner's syndrome

The tissue sensitivity to insulin and the metabolic clearance rate of insulin were evaluated in a new case of Werner's syndrome, by means of the euglycemic clamp technique using an artificial endocrine pancreas. The possible contribution of pancreatic insulin secretion and of reduced hepatic insulin breakdown to the peripheral hyperinsulinism was also studied by simultaneous determination of C-peptide and insulin levels and by analysis of the C-peptide/insulin molar ratio. The data obtained are consistent with the presence of marked insulin resistance and of reduced metabolic clearance rate of insulin in our patient, confirming what has been observed previously using other techniques. The finding of a reduced C-peptide to insulin ratio during the intravenous glucose tolerance test suggests that hepatic extraction of insulin could also be altered in Werner's syndrome, as found in several hyperinsulinism conditions, therefore contributing to peripheral hyperinsulinism.

Effects of mixing short- and intermediate-acting insulins on absorption course and biologic effect of short-acting preparation

The effects of mixing short- and intermediate-acting insulins (Actrapid MC and Monotard MC) were studied in seven diabetic patients. On different days, 0.16 IU/kg of Actrapid and 0.24 IU/kg of Monotard were administered to each subject in separate injections and combined in the same syringe. Free-insulin curves and the biologic effect of insulin, assessed by the glucose-clamp technique, were compared. The absorption rate of regular insulin was higher when injected separately from the intermediate-acting preparation: the incremental areas of free insulin above basal levels, up to 90 min after the administration of the hormone, were 32 +/- 5 vs. 21 +/- 3 microU X ml-1 X min-1 (P less than .02). In the same period, glucose infused to sustain glycemia showed no significant differences (2.8 +/- 0.4 vs. 2.4 +/- 0.3 mg X kg-1 X min-1 after the administration of insulin in separate and combined injection, respectively). The difference in insulin profiles is not translated into a significant difference in glucose requirement. This might be a consequence of a flattening of the insulin dose-response curve due to insulin resistance of diabetic subjects. The slight delay in insulin action of Actrapid when mixed with Monotard is probably irrelevant in clinical practice.

Effect of long-term near-normoglycemia on the progression of diabetic nephropathy

The effect of prolonged restoration of near-normoglycemia on the progression of diabetic nephropathy was evaluated in a controlled study in which 10 insulin-dependent (type 1) diabetic patients with clinical proteinuria were randomized to continue with conventional insulin treatment (CIT) or to undertake more intensive diabetic therapy using continuous subcutaneous insulin infusion (CSII). The patients, mean age 33 +/- 8 yr, mean duration of diabetes 15 +/- 4 yr, were studied before and during 12 months of either CIT or CSII therapy. Glycemic control was assessed by means of mean blood glucose (MBG) +/- Standard deviation (SD), urinary glucose excretion and glycosylated hemoglobin, while renal function was assessed by albumin, IgG and beta-2-microglobulin urinary excretion rates, serum creatinine and creatinine clearance. Blood glucose level, urinary glucose excretion and glycosylated hemoglobin fell significantly in the CSII group, while no differences were found in the CIT group after the 12 months observation period. Both groups showed a deterioration in all indices of renal function, as illustrated by an increase of protein excretion rates and of serum creatinine, and by a decline in creatinine clearance. Comparison of the rate of increase of urinary albumin and IgG excretion and of serum creatinine and of the rate of fall in creatinine clearance between CIT and CSII groups demonstrated that the rate of progression of diabetic nephropathy may be slowed by correction of hyperglycemia. Our study, with due reservations because of the small number of examined patients and differences in kidney function at the beginning of the trial shows that intensive diabetic care may play a role in the proteinuric stage of diabetes in slowing further destruction of residual glomerular structure and in delaying end stage renal failure.

The euglycemic clamp technique in patients with liver cirrhosis

Tissue sensitivity to insulin and insulin metabolic clearance rate were assessed by means of the euglycemic clamp technique in 11 controls and 11 patients with liver cirrhosis. The method was carried out using an artificial endocrine pancreas. The amount of glucose infused to keep euglycemia, as well as the ratio of glucose infused to steady-state insulin level, were significantly lower in cirrhotics as compared to controls (p less than 0.001). The metabolic clearance rate of insulin did not show significant differences between the two groups. Our results confirm that a marked insulin resistance is present in cirrhotics, as previously shown by means of different techniques.

Diabetes as pro-infective risk factor in total hip replacement

It is widely accepted that diabetic patients, above all poorly controlled ones, are more susceptible to infection. To verify whether diabetes might be considered a pro-infective risk factor in total hip replacement, 1,042 patients, who from 1969 to 1979 underwent an operation for arthropros thesis of the hip, were studied. The patients were subdivided into two groups according to whether they were diabetic or not. The diabetic patients, though well controlled by diet or by diet plus oral hypoglycemic agents, received insulin for at least two days before surgery. In the early post-operative phase they showed transient worsening of glycemic control rapidly corrected by increased insulin dosage. The patients of both groups were operated in low air exchange operating theaters, by the same staff and using standardized surgical techniques, and all received antibiotic coverage as preventive treatment against infections for a week after surgery. Infection and suppuration occurred in 11% of diabetic patients and only in 2% of non-diabetic patients (p less than 0.001); in these cases the prostheses were removed after unsuccessful antimicrobial treatment. Our study indicates that diabetes mellitus must be considered a proinfective risk factor in patients who undergo an operation for total hip replacement and suggests that a conservative approach is required in diabetic patients.

Lipid abnormalities in insulin-dependent diabetic patients with albuminuria

The relationship between serum lipid, lipoprotein, and apolipoprotein levels and abnormalities of renal function has been investigated in 112 insulin-dependent (type I) diabetic patients. They were subdivided into three matched groups according to the amount of albuminuria: group A (albuminuria less than 20 micrograms/min), group B (albuminuria between 20 and 150 micrograms/min; Albustix negative), and group C (albuminuria greater than 150 micrograms/min; Albustix positive). Twenty-one nondiabetic subjects with albuminuria above 150 micrograms/min but without nephrotic syndrome and/or renal failure and 77 healthy subjects were also studied. Mean total and LDL cholesterol, triglycerides, and apo B were higher, while HDL cholesterol and HDL/LDL cholesterol ratio were lower in group C than in groups A and B; the apo A/apo B ratio was lower in group C than in group A. Differences in apo B and in apo A/apo B ratio were found between groups A and B. No correlation between lipid parameters and amount of albuminuria was observed. Significant differences in lipid concentrations were also found in diabetic patients when compared with nondiabetic subjects with albuminuria and with healthy subjects. The present study confirmed previous reports of lipid disorders in insulin-dependent (type I) diabetes; however, the most important observation was the finding of albuminuria-related differences in lipid parameters in diabetic patients without renal failure. We think that the greater lipid abnormalities observed in diabetic patients with larger amounts of albuminuria might be the consequence both of impairment of glomerular permeability and of the diabetic state.

Insulin-dependent metabolism of branched-chain amino acids in obesity

The effect of euglycemic hyperinsulinism on branched-chain amino acids (BCAA; valine, isoleucine and leucine) was evaluated in five obese subjects and five controls. A continuous intravenous insulin infusion raised plasma insulin to a steady-state level. An artificial endocrine pancrease that infused glucose was used to sustain euglycemia. Basal and steady-state insulin levels were significantly higher in the obese subjects than in the controls. The amount of glucose infused to maintain euglycemia and its ratio to steady-state insulin levels was significantly lower in the obese subjects, suggesting an impaired insulin action on glucose metabolism. Basal BCAA levels were similar in the two groups of subjects. During insulin infusion the decremental areas of BCAA below basal levels were significantly lower in the obese patients (63 +/- 5 nmol/mL X min v 143 +/- 8 nmol/mL X min, P less than 0.001), as was the ratio of the decremental areas of BCAA to the incremental areas of insulin (1.11 +/- 0.05 nmol/microU v 3.30 +/- 0.24 nmol/microU, P less than 0.001). Our data suggest that insulin resistance in obesity reduces hormonal effects on glucose as well as on BCAA metabolism.

Kidney function after improved metabolic control in newly diagnosed diabetes and in diabetic patients with nephropathy

To evaluate the effect of improved metabolic control on kidney function, urinary excretion rate of beta-2-microglobulin, lysozyme, and gamma-glutamyltransferase were evaluated in nine poorly controlled, newly diagnosed diabetic patients before and during treatment. In six poorly controlled insulin-dependent nephropathic diabetic patients, besides the parameters cited above, urinary albumin excretion rate and IgG/transferrin clearance ratio were further investigated to estimate the permeability and the selectivity of glomerular barrier during conventional treatment and after improvement of the metabolic control by a glucose-controlled insulin infusion system (GCIIS). The improved glycemic control resulted in a significant reduction of urinary beta-2-microglobulin and lysozyme excretion in all diabetic patients. Significant decreases of urinary albumin excretion and of IgG/transferrin clearance ratio (indicating a more selective proteinuria) during strict metabolic control were also observed in nephropathic diabetic patients. The reduction of urinary beta-2-microglobulin and lysozyme excretion indicates that a tubular reabsorptive dysfunction, reversible with the amelioration of glycemic control, can be observed in poorly controlled, newly diagnosed and in insulin-dependent nephropathic diabetic patients during conventional treatment. In the latter patients, the permeability and the selectivity properties of glomerular barrier also improved during GCIIS.

Branched-chain amino acids and alanine as indices of the metabolic control in type 1 (insulin-dependent) and type 2 (non-insulin-dependent) diabetic patients

Alterations in plasma branched-chain amino acids (valine, isoleucine and leucine) and alanine have been described in patients with insulin-dependent diabetes mellitus who have poor metabolic control. To assess the relevance of these abnormalities as indices of metabolic control, we sequentially evaluated plasma amino acids in 14 poorly controlled diabetics (seven Type 1 (insulin-dependent) and seven Type 2 (non-insulin-dependent) patients) until good control was achieved. The sum of branched-chain amino acids in both groups of uncontrolled diabetic patients was significantly increased compared with the values for the same subjects in good metabolic control. No statistically significant differences were present between ketotic and non-ketotic uncontrolled patients. The amelioration of the diabetic state with either insulin treatment or oral hypoglycaemic agents, reduced progressively branched-chain amino acids. The sum of valine, isoleucine and leucine strictly correlated with daily urinary glucose (r = 0.73), but less well with fasting blood glucose (r = 0.43), non-esterified fatty acids (r = 0.46) and glycosylated haemoglobin (r = 0.38). Alanine did not show any statistically significant differences at various stages of diabetic control. Branched-chain amino acids, but not alanine, may be used as indices of short-term diabetic control.

The molar ratio of C-peptide to insulin after two consecutive stimulations with glucagon in obesity

The same dose (1 mg) of intravenous glucagon, administered in two consecutive pulses, demonstrates that insulin and C-peptide secretory responses in obese patients exceed those of normal weight subjects. The analysis of the molar ratio of serum immunoreactive C-peptide (IRCP) to serum immunoreactive insulin (IRI) which revealed significant differences between obese and control groups suggests that higher plasma insulin levels in obesity may result not only from a greater response to glucagon loads and from an impaired sensitivity to endogenous insulin by target tissues, but also from a decreased hepatic removal and destruction of the hormone. Perhaps an anomaly in the hepatic handling of insulin exists in obese subjects and thus a greater amount of the hormone reaches the periphery contributing to hyperinsulinemia, as observed in hyperglycemic and hyperinsulinemic obese (ob/ ob) mice.