Leucocyte count,proteinuria and smoking in type 1 diabetes mellitus

A case-control study was carried out to analyse leucocyte counts in relation to proteinuria and smoking in type 1 (insulin-dependent) diabetes. The subjects were 180 smoking (87 women, age 32±11 years, diabetes duration 14±6 years) and 188 nonsmoking (88 women, age 32±11 years, diabetes duration, 14±6 years) type 1 diabetic patients. Leucocyte counts were higher in smokers than in nonsmokers, both in women (7.6±2.3 vs 6.8±1.9×10⁹/l,P<0.01) and in men (8.1±2.7 vs 6.4±2.0×10⁹/l,P<0.0001). Leucocyte counts correlated with the number of cigarettes smoked per day (r=0.32,P<0.0001), but were unrelated to glycosylated haemoglobin levels. Among nonsmokers, leucocyte counts were comparable between patients with normal proteinuria (6.7±2.2×10⁹/l,n=106), microproteinuria (6.3±1.7×10⁹/l,n=66) and macroproteinuria (6.8±1.1×10⁹/l,n=16). Among smokers, patients with macroproteinuria or microproteinuria had higher leucocyte counts than those with normal proteinuria [8.9±3.0×10⁹/l, (n=36) vs 8.4±2.7×10⁹/l (n=61) vs 7.0±1.9×10⁹/l (n=83)P<0.0001], a finding which was not due to differences in the number of cigarettes smoked per day. It is concluded that in these type 1 diabetic patients leucocyte counts were higher in smokers than in nonsmokers. Among non-smokers leucocyte counts were comparable between patients with normal proteinuria and increased proteinuria, whereas among smokers leucocyte counts were higher in patients with increased proteinuria. It appears it would be worthwhile examining in prospective studies whether leucocyte counts can contribute to identifying those type 1 diabetic patients with a particularly high risk of cardiovascular complications.     

Relative roles of insulin and hypoglycaemia on induction of neuroendocrine responses to,symptoms of,and deterioration of cognitive function in hypoglycaemia in male and female humans

Summary To assess the relative roles of insulin and hypoglycaemia on induction of neuroendocrine responses, symptoms and deterioration of cognitive function (12 cognitive tests) during progressive decreases in plasma glucose, and to quantitate glycaemic thresholds, 22 normal, non-diabetic subjects (11 males, 11 females) were studied on four occasions: prolonged fast (n=8, saline euglycaemia study, SA-EU), stepped hypoglycaemia (plasma glucose plateaus of 4.3, 3.7, 3 and 2.3 mmol/l) or euglycaemia during insulin infusion at 1 and 2 mU·kg^–1·min^–1 (n=22, high-insulin hypoglycaemia and euglycaemia studies, HI-INS-HYPO and HI-INS-EU, respectively), and stepped hypoglycaemia during infusion of insulin at 0.35 mU· kg^–1·min^–1 (n=9, low-insulin hypoglycaemia study, LO-INS-HYPO). Insulin per se (SA-EU vs HI-INS-EU), suppressed plasma glucagon (20%) and pancreatic polypeptide (30%), whereas it increased plasma noradrenaline (R10%, p<0.05). Hypoglycaemia per se (HI-INS-HYPO vs HI-INS-EU) induced responses of counterregulatory hormones (CR-HORM), symptoms and deteriorated cognitive function. With the exception of suppression of endogenous insulin secretion, which had the lowest glycaemic threshold of 4.44±0.06 mmol/l, pancreatic polypeptide, glucagon, growth hormone, adrenaline and cortisol had similar glycaemic thresholds (3.8-3.6 mmol/l); noradrenaline (3.1±0.0 mmol/l), autonomic (3.05±0.06 mmol/l) and neuroglycopenic (3.05±0.05 mmol/l) symptoms had higher thresholds. All 12 tests of cognitive function deteriorated at a glycaemic threshold of 2.45±0.06 mmol/l, but 7 out of 12 tests were already abnormal at a glycaemic threshold of 2.89±0.06 mmol/l. Although all CR-HORM had a similar glycaemic threshold, the lag time of response (the time required for a given parameter to increase) of glucagon (15±1 min) and growth hormone (14±3 min) was shorter than adrenaline (19±3 min) and cortisol (39±4 min) (p<0.05). With the exception of glucagon (which was suppressed) and noradrenaline (which was stimulated), insulin per se (HI-INS-HYPO vs LO-INS-HYPO) did not affect the responses of CR-HORM, and did not influence the symptoms or the cognitve function during hypoglycaemia. Despite lower responses of glucagon, adrenaline and growth hormone (but not thresholds) in females than males, females were less insulin sensitive than males during stepped hypoglycaemia.     

Hyperproinsulinaemia in patients with myotonic dystrophy

Summary Hyperinsulinaemia is a reported feature of the inherited multisystem disorder myotonic dystrophy. This phenomenon has been attributed to a compensatory beta cell response to tissue insulin resistance. In this study, circulating concentrations of insulin, proinsulin, and split proinsulin molecules were determined after an overnight fast in ten patients with myotonic dystrophy using two-site monoclonal antibody-based immunoradiometric assays. Results were compared with ten healthy control subjects matched for age, gender, and body mass index. Oral glucose tolerance (75 g), as defined by World Health Organization criteria, was normal in all subjects. Fasting plasma immunoreactive insulin concentration, as determined using a conventional radioimmunoassay, was almost three times higher (p<0.005) in the myotonic dystrophy patients than the healthy control subjects. By contrast, fasting concentrations (mean±SEM) of C-peptide (0.75±0.09 vs 0.52±0.03 nmol/l, p=0.07) and immunoradiometrically-determined insulin (60±12 vs 38±4 pmol/l, p=0.09) were not significantly different between the groups. Fasting concentrations of proinsulin (10.3±2.9 vs 1.6±0.3 pmol/l, p<0.01), and 32–33 split proinsulin (7.8±2.5 vs 2.9±0.4 pmol/l, p<0.05) were significantly elevated in the patients with myotonic dystrophy. Accordingly, the mean fasting proinsulininsulin ratio, expressed as a percentage, was significantly increased in the myotonic patients (20±5 vs 4±1%, p<0.01). The overall C-peptide response to the oral glucose challenge was significantly greater in the myotonic patients compared with the healthy control subjects (p<0.001). These results provide corroborative evidence of increased beta-cell secretion in myotonic dystrophy. In addition, myotonic dystrophy is characterised by elevated plasma concentrations of proinsulin-like molecules which may cross-react in insulin radioimmunoassays.     

Radiofrequency Ablation in Pediatric and Adult Patients: Comparative Results

Background: Radiofrequency (RF) catheter ablation has been widely and successfully employed to cure adult and pediatric patients of a variety of arrhythmias. Only limited data exist which compare the results in these two groups. The aim of this study was to compare the efficacy and safety of RF catheter ablation in pediatric versus adult patients performed by an adult electrophysiology (EP) team. Methods: The study group included 327 consecutive pediatric (n=47) and adult (n=280) patients, aged 7–82 years (mean 40±19), with symptomatic tachyarrhythmias, who underwent RF ablation during the last 6 years. All but ten patients underwent a full EP study during the same session. Procedures were performed in all but five patients with use of local anesthesia and deep or light sedation. The left heart was approached with use of transaortic (n=36) or transseptal (n=55) or both (n=6) techniques. RF ablation was performed for manifest or concealed accessory pathways in 132 patients, AV nodal slow pathway in 119, atrial tachycardia in 24, atrial flutter in 15, atrial fibrillation in one, ventricular tachycardia in 29, and AV node/His bundle in 7 patients. Results: RF ablation was successful in 271 (96.8%) patients in the adult group and in all patients (100%) in the pediatric group, with a mean of 15±18 (median: 8) vs 12±10 (median: 8) RF applications respectively (P=NS). Complications occurred in four patients (1.4%) in the adult group and in one patient (2.1%) in the pediatric group (P=NS). Fluoroscopy time averaged 43±40min vs 39±27min and procedures lasted for 3.0±1.9 hours vs 2.8±1.4 hours respectively (P=NS). During long-term follow-up of 25±19 months, there were 12 (4.4%) recurrences among the adult patients, and three (6.4%) recurrences in children, with nine of them successfully treated with repeat RF ablation. Procedural variables were dependent on the type of arrhythmia ablated, rather than on patients age. Patients with multiple accessory pathways or atrial flutter required the greatest number of RF applications and the longest fluoroscopy exposure and duration of the procedure; the lowest values of these variables concerned ablation of the slow AV nodal pathway or the AV node/His bundle. Conclusion: RF ablation in adult and pediatric patients performed by an adult EP team is equally efficacious and safe offering cure of symptomatic cardiac tachyarrhythmias in both patient populations.     

PMN-elastase in assessment of patients with inflammatory bowel disease

PMN-elastase is a proteinase released by activated neutrophils. PMN-elastase was determined in two independent populations with inflammatory bowel disease. In an unselected population of 70 consecutive patients with Crohn's disease and 24 patients with ulcerative colitis with different degrees of disease activity plasma PMN-elastase levels were statistically significantly higher in patients with active than in patients with inactive disease [Crohn's disease: 80.5±33.2 ng/ml vs 60.1±24.6 ng/ml (means±sd),P=0.0017; ulcerative colitis: 98.2±54.9 ng/ml vs 59.2±16.8 ng/ml,P=0.026]. PMN-elastase levels in feces were also higher in patients with active Crohn's disease (23.6±15.3 ng/g vs 13.6±12.5 ng/g,P=0.0021) and active ulcerative colitis (46.5±60.5 ng/g vs 20.2±25.0 ng/g,P=0.46), but the difference reached significance only in Crohn's disease. Correlation of disease activity and PMN-elastase in individual patients showed a statistically significant correlation between plasma and fecal elastase concentrations and disease activity in ulcerative colitis (plasma:r=0.72,P<0.001; feces:r=0.423,P<0.001) but not fecal elastase concentrations (r=0.0083,P=0.485) correlated significantly with disease activity. Plasma PMN-elastase correlated weakly with fecal PMN-elastase levels in Crohn's disease (r=0.431,P<0.01) and in ulcerative colitis (r=0.515,P=0.05). In 28 patients with highly active Crohn's disease [median severity activity index (SAI) 203] and 11 patients with highly active ulcerative colitis [median Rachmilewitz index (RI) 14] studied before and four weeks after steroid therapy, treatment lowered the median SAI to 140 and the median RI to 4.5. Mean plasma elastase concentrations decreased concomitantly from 83±44.9 ng/ml to 61.8±25.8 (P=0.0035) in patients with Crohn's disease and from 110±49.5 to 71.6±28.8 ng/ml (P=0.0069) in patients with ulcerative colitis. In conclusion, there is a release of PMN-elastase in active IBD, which can be detected in plasma as well as in feces. Plasma elastase levels reflect disease activity in patients with IBD. The variation of the data and the large overlap between different groups, however, strongly reduce the clinical value.This research was supported by the SFB 154 of the Deutsche Forschungsgemeinschaft. V. Gross is supported by a Heisenberg-Stipendium of the Deutsche Forschungsgemeinschaft.     

Salt-sensitivity is associated with a hyperinsulinaemic and hyperglycaemic response to atrial natriuretic peptide infusion in human essential hypertension

Summary To evaluate the influence of salt-sensitivity on the plasma insulin and glucose response to infusion of ANP, we studied 22 men with essential hypertension, who were between 40 and 60 years old. After 1 month under normal Na⁺ intake (120 mmol Na⁺ per day), patients were randomly assigned to receive either ANP (0.04 g · kg^–1 · min^–1) (n=15) or vehicle (50 ml saline) (n=7) over a 60-min period, while in the supine position. Plasma insulin and glucose were measured at time –60, 0, 20, 40, 60, 120, 180, 240 min. Ten days after ANP infusion, blood pressure sensitivity to changes in di etary salt intake was assessed according to a randomized double-blind crossover protocol. Patients were classified into two groups either salt-sensitive (n=8) or salt-resistant (n=7). Our results showed that plasma insulin and glucose did not change during ANP infusion in both groups. However, both plasma insulin (from 75.6 ± 45.1 pmol/l at 60 min to 121.2 ± 48.6 pmol/l at 240 min, p <0.05 vs time 0) and glucose levels (from 4.86 ± 0.73 mmol/l at 60 min to 6.56 ± 1.03 mmol/l at 240 min, p <0.01 vs time 0) rose after discontinuation of ANP in salt-sensitive patients, but did not change at all in salt-resistant patients. In conclusion, this randomized vehicle-controlled study demonstrates that plasma insulin and glucose levels increase in salt-sensitive hypertensive patients after the infusion of ANP. The increase of plasma insulin levels observed after ANP discontinuation, if occurring under physiologic conditions, could influence the blood pressure sensitivity to dietary Na⁺ intake.Abbrevations ANP Atrial natriuretic peptide - NIDDM non-insulin dependent diabetes mellitus     

Neprilysin levels in plasma and synovial fluid of juvenile idiopathic arthritis patients

Objective Neprilysin (neutral endopeptidase, 3:4:24:11, CD10) (NEP) is a Zn metallopeptidase linked to controlling inflammation through the degradation of neuropeptides involved in neurogenic inflammation of chronic rheumatic diseases. The aim of our study was to evaluate circulating activity and cellular expression of NEP in the plasma of 58 children with juvenile idiopathic arthritis (JIA) and 52 controls. In 20 subjects requiring local steroid injection, NEP was measured in synovial fluid.Methods Plasma and synovial NEP were evaluated using a fluorimetric technique. Neprilysin, expressed as the antigen CD10, was determined on circulating and synovial fluid cells as mean fluorescence intensity (MFI) and as percentage of positive cells by two-color immunofluorescence.Results Circulating NEP levels were lower in JIA patients than in controls (42.0±16.6 vs 76.5±24 pmol/ml per min, P<0.001), while synovial fluid NEP values were higher than circulating levels (241.4±86.2 vs 40±15.3 pmol/ml per min, P<0.001). In monocytes, the percentage of CD10-positive circulating cells and the MFI in JIA were lower than in controls (11.6±5.2% vs 41.4±13%, P<0.001 and 18.1±7.5 vs 31.2±5.4, P<0.05, respectively). On synovial monocytes, the percentage of CD10-positive cells and the MFI were higher than on circulating monocytes (35.2±14.6% vs 9.1±2.4%, P<0.001 and 66.4±5.4 vs 22.8±14.7, P<0.001, respectively).Conclusions The downregulation of CD10 expression in monocytes and the reduction in NEP activity may be linked to the enzymes role in the control of peptides involved in the inflammation. The increased levels of NEP, MFI, and CD10-positive monocytes in synovial fluid, even though in plasma, might reflect a reactive effort to control synovial proliferation.     

Dietary phosphate restriction in dialysis patients: A new approach for the treatment of hyperphosphataemia

Background and Aim

Elevated serum phosphate and calcium–phosphate levels play an important role in the pathogenesis of vascular calcifications in uraemic patients and appear to be associated with increased cardiovascular mortality. We aimed to evaluate the effects of a partial replacement of food protein with a low-phosphorus and low-potassium whey protein concentrate on phosphate levels of dialysis patients with hyperphosphataemia.

Methods and Results

Twenty-seven patients undergoing chronic haemodialysis were studied for a 3-month period. In the intervention group (n = 15), food protein were replaced by 30 or 40 g of low-phosphorus and low-potassium protein concentrate aimed at limiting the phosphate intake. In the control group (n = 12) no changes were made to their usual diet. Anthropometric measurements, biochemical markers and dietary interviews were registered at baseline and during the follow-up period. From baseline to the end of the study, in the intervention group, serum phosphate and circulating intact parathyroid hormone levels lessened significantly (8.3 ± 1.2 mg/dL vs 5.7 ± 1.4 mg/dL and 488 ± 205 pg/ml vs 177 ± 100 pg/ml respectively; p < 0.05) with decreasing of phosphate and potassium intake. No significant differences were found in the control group. No significant changes were observed in serum albumin, calcium, potassium, Kt/V, body weight and body composition in both the intervention and control groups.

Conclusion

Dietary intake of phosphate mainly comes from protein sources, so dietary phosphorus restriction may lead to a protein/energy malnutrition in a dialysis patient. A phosphorus-controlled diet plan including a nutritional substitute resulted in serum phosphate and intact parathyroid hormone decrease without nutritional status modifications in dialysis patients.     

Effects of chronic neutral endopeptidase inhibition on the progression of left ventricular dysfunction and remodeling in dogs with moderate heart failure

Background. The diuretic actions of endogenously produced atrial natriuretic factor (ANF) may be beneficial in the treatment of chronic heart failure (CHF). Neutral endopeptidase (NEP) is the primary enzyme responsible for the degradation of ANF. The present study investigates the effects of long-term NEP inhibition on the progression of left ventricular (LV) dysfunction and remodeling in dogs with moderate heart failure. Methods. LV dysfunction was produced in 12 dogs by multiple sequential intracoronary microembolizations. Embolizations were discontinued when LV ejection fraction (EF) was between 30–40%. Two weeks after the last embolization, dogs were randomized to 3 months of oral therapy with the NEP inhibitor ecadotril (100 mg, once daily, n = 6) or to no therapy at all (control, n = 6). Results. During the 3 months of follow-up, LV EF in control dogs decreased from 37 ± 1% to 28 ± 1% (P < 0.01) and LV end-diastolic volume (EDV) and end-systolic volume (ESV) increased (EDV: 72 ± 3 vs. 84 ± 5 ml, P < 0.01); ESV: 45 ± 1 vs. 60 ± 4 ml, P < 0.01). In dogs treated with ecadotril, LV EF (34 ± 1% vs. 37 ± 2%), EDV (79± 5 vs. 78± 6 ml) and ESV (52 ± 3 vs. 49 ± 4) remained essentially unchanged after 3 months of therapy. Histomorphometric measurements at the termination of the study showed that ecadotril was associated with significantly reduced cardiomyocyte hypertrophy compared to control. Conclusion. Early, long-term NEP inhibition with ecadotril prevents the progression of LV dysfunction and attenuates progressive LV remodeling in dogs with moderate heart failure.     

Interleukin-6 in synovial fluid is closely associated with chronic synovitis in rheumatoid arthritis

Summary Interleukin-6 (IL-6) was detected at low levels in plasma [0.014±0.006 ng/ml (mean ± SEM] and in high amounts in synovial fluid [SF; 2.6±2.2 ng/ml (mean ± SEM)] of patients with rheumatoid arthritis. No correlation of IL-6 levels in plasma or SF with the ESR (n=15) or with histological parameters of acute local synovitis (n=10) was observed. In contrast, SF IL-6 was positively correlated with histological characteristics of chronic synovitis (n=10; P0.01) and elevated plasma IgG concentrations (n=15; P0.05). In vitro concentrations of IL-6 comparable to those detected in SF increased the production of both IgG and IgM by synovial membrane mononuclear cells. The present results contribute to the view that high local IL-6 concentrations in SF promote chronic synovitis in RA.     

Elevated serum angiotensin I converting enzyme activity in type I,insulin-dependent diabetic subjects with persistent microalbuminuria

Angiotensin I-converting enzyme (ACE), which is synthesized by vascular endothelial cells, is sometimes elevated in diabetic subjects. To determine whether serum ACE is elevated in subjects at high risk of malignant microangiopathy, serum ACE activity in 34 normotensive, type 1 insulin-dependent diabetic subjects with persistent microalbuminuria (30–300 mg/24 h) was compared with that in 30 normotensive, normoalbuminuric type 1 diabetic subjects of the same age [37±15 (mean ±SD) vs 38±14 years], sex (21 M/13 F vs 15 M/15 F), stage of retinopathy (14 vs 16 nil/11 vs 7 background/6 vs 4 preproliferative/3 vs 3 proliferative) and HbA_1c (7.7±1.9 vs 8.2±1.0%). Serum ACE activity of diabetic subjects was also compared with 120 age and sex related healthy controls. Serum ACE activity was higher in subjects with microalbuminuria than in those with normoalbuminuria (406±114 vs 359±97 IU/l;P=0.03), or in controls (307±95 IU/l;P=0.0001). Normoalbuminuric subjects also had higher ACE activity than controls (P=0.02). Serum ACE activity was not related to diabetes duration (r=0.01; NS), HbA_1c (r=0.05; NS), or stage of retinopathy in diabetic subjects (r=0.06; NS), while stage of retinopathy was related to age (r=0.42;P=0.003) and to diabetes duration (r=0.74;P=0.0001) in these subjects. Elevated ACE activity occurs in type 1 diabetic subjects, especially in those with microalbuminuria. This may give early indication of lesions in vascular endothelial cells.This work was presented at the 27th meeting of the European Association for the Study of Diabetes in Dublin, Ireland, 10–14 September 1991, and published in an abstract form: Diabetologia (1991) 34: A17     

Elevated serum homocysteine levels for gouty patients

Our objective was to analyze serum total homocysteine (tHcy) levels for gouty patients and to study whether there are any level changes following treatment with allopurinol. We enrolled 90 male participants including patients with primary gout (n=51) and community-based healthy controls (n=39). Fasting tHcy levels were determined for all subjects and repeat measurements performed for 29 patients following treatment with allopurinol. The results revealed that gouty patients exhibited significantly greater serum tHcy levels (12.10±3.19 mol/l) than healthy controls did (9.96±2.16 mol/l) (p=0.0003), although there was no obvious difference between the pre-allopurinol treatment group (12.54±3.31 mol/l) and its post-treatment analogue (11.90±4.68 mol/l) (n=29, p=0.33). Elevated serum levels of tHcy were noted for this cohort of male gouty patients as compared to healthy controls, and these tHcy levels did not appear to change substantially following treatment with allopurinol. Although the pathogenesis of hyperhomocysteinemia for gouty patients still remains somewhat obscure, this study suggests that tHcy levels cannot be effectively modulated by treatment with allopurinol.     

Glucose regulates both glucose transport and the glucose transporter gene expression in a hamster-derived pancreatic Beta-cell line (HIT)

Summary We studied the effect of chronic exposure to high glucose on the glucose transport regulation in hamster pancreatic Beta cells in permanent culture (HIT). Cells were exposed to either 5.5 mmol/l or 16.7 mmol/l glucose for 48 h and then glucose transport was studied by measuring the (³H)-2-deoxyglucose uptake for 5 and 10 min at 37 °C. The 2- deoxyglucose uptake was lower in cells pre-exposed to glucose 16.7 mmol/l for 48 h compared to cells pre-exposed to glucose 5.5 (12.0±1.6 vs 19.1±1.2 nmol/0.1 mg after 5 min, and 22.2±2.6 vs 39.0±2.9 after 10 min respectively, mean ±SEM, n=5, p < 0.01). In order to investigate the mechanism(s) for glucose impairment of glucose transport, we studied the glucose carrier gene expression in the same cells by Northern and slot-blot analysis. When total RNA was extracted from HIT cells cultured at either 5.5 or 16.7 mmol/l glucose and then hybridized to ³²P-labelled cDNA probes for the glucose transporter 1, the glucose transporter 2 and -actin, a significant reduction of both glucose transporter 1 (–63.9±4.1%, mean±SEM, n=3) and glucose transporter 2 (–48.9±3.2%) mRNA was observed in HIT cells cultured with high glucose. In the same experiments no change of -actin mRNA was observed, suggesting that the effect of high glucose was specific on the glucose-transporter mRNAs. In HIT cells cultured at glucose 16.7 mmol/l the glucose-induced insulin release was also reduced compared to cells cultured at glucose 5.5 (715±19 U · h^–1 · mg^–1 vs 1301±28 U · h^–1 · mg^–1, respectively, mean ±SEM, n=3, p < 0.05). In conclusion, in hamster pancreatic Beta-cells, chronic exposure to high glucose concentrations impairs glucose transporter mRNA levels, glucose transport, and glucose-induced insulin secretion in a co-ordinate manner. Note: After this paper was submitted we became aware of two recent publications [9, 10] showing in animal models of non-insulin-dependent diabetes a decreased expression of the Beta-cell glucose transporter in pancreatic islets unresponsive to glucose, further supporting the view that this transporter may play a role in the glucosesensing mechanism.     

Increased urinary albumin excretion aggregates with atherosclerotic risk factors in type 2 (non-insulin-dependent) diabetes mellitus

Supranormal urinary albumin excretion (microalbuminuria) is an early indicator of microangiopathy, i.e. diabetic nephropathy, and is associated with higher cardiovascular mortality in both type 1 and type 2 diabetes. The relationship between the presence of microalbuminuria and some atherosclerotic risk factors has been evaluated in 318 (170 male, 148 female) type 2 (non-insulin-dependent) diabetic subjects [age 63±10 years; known duration of diabetes 10.9±8.8 years; age at diabetes diagnosis 52±11 years; systolic blood pressure (BP) 150±23 mmHg; diastolic BP 86±11 mmHg (mean±SD)]. In early morning urine samples, albumin (immunonephelometry) and creatinine were assayed. On the basis of the albumin/creatinine ratio (A/C, mg/mmol), patients were categorized as normoalbuminuric (Na; A/C<2.0;n=159, 50%), microalbuminuric (ma; A/C 2–20;n=135, 42.5%) or macroalbuminuric (Ma; A/C >20;n=24, 7.5%). The three groups were closely matched for age, age at diagnosis, duration of diabetes, and fasting plasma and urinary glucose levels. Systolic and diastolic BP rose progressively with increasing urinary A/C ratio levels. While high-density lipoprotein (HDL) cholesterol was unaffected by albuminuria, total cholesterol (218±45 vs 198±43 mg/dl,P<0.001) and low-density lipoprotein (LDL) cholesterol (145±42 vs 131±38 mg/dl,P<0.05) levels were higher in microalbuminuric than in normoalbuminuric patients. Further, a significant correlation (r=0.16,P<0.01) existed between albuminuria and triglyceride concentrations. Prevalence of arterial hypertension, defined as BP160/95 mmHg and/or drug treatment (Na, 51%; ma, 65%; Ma, 78%;P<0.001) and obesity, defined as body mass index (BMI)>30 (Na, 15%; ma, 26%; Ma, 32%;P<0.05) rose with increasing A/C ratios. Both coronary heart disease (30% vs 15%) and intermittent claudication (18% vs 7%) were more frequent in microalbuminuric than in normoalbuminuric subjects. Finally, multiple stepwise regression analysis showed that urinary albumin excretion is significantly and independently associated with coronary heart disease and intermittent claudication, also taking into account hypertension and other established cardiovascular risk factors. In type 2 diabetes microalbuminuria tends to aggregate with risk factors for atherosclerotic vascular disease, e.g. increased prevalence of hypertension and obesity, elevated total and LDL cholesterol, and raised triglycerides levels. These abnormalities may only explain the excess of cardiovascular morbidity and mortality in part. Microalbuminuria per se may be an important and independent cardiovascular risk factor.     

Humoral SPARC/osteonectin protein in plasma cell dyscrasias

The matricellular protein SPARC (secreted protein acidic and rich in cysteine)/osteonectin was determined in patients with multiple myeloma and related disease to assess the hypothesized role of SPARC as a possible marker of tumor burden and disease progression. Soluble SPARC was measured by competitive enzyme-linked immunosorbent assay (ELISA) in plasma of 42 patients, including sequential measurements in individual patients, and in 20 healthy controls. SPARC values were heterogeneous in multiple myeloma patients showing a decline from baseline levels recorded in controls (456±195 vs 600±63 ng/ml, p=0.00023). A SPARC showed a significant positive correlation with platelet count (r=0.72, p=0.000000, n=42), hemoglobin (r=0.52, p=0.00037, n=42), and IgG level (r=0.43, p=0.0085, n=42) and negative correlation with ₂-microglobulin (r=–0.46, p=0.0023, n=42), aspartate aminotransferase (AST) (r=–0.42, p=0.0061, n=41), interleukin (IL)-6 (r=–0.41, p=0.008, n=42), lactate dehydrogenase (LDH) (r=–0.36, p=0.02, n=41), and percentage of plasma cells in bone marrow aspirate (r=–0.34, p=0.029, n=42). No correlation was found between SPARC and M component or disease stage. Investigations performed during the course of disease, including sequential measurements in individual patients, showed a trend to downregulation by disease progression, with the lowest level recorded in the terminal stage (217±107 ng/ml, n=11). Patients with established osteolytic lesions had lower plasma SPARC at diagnosis (309±197 vs 581±293, p=0.021), which correlated with osteocalcin by disease progression (r=0.31, p=0.026). The results of this pilot study revealed abnormalities in the level of humoral SPARC in multiple myeloma and an overall trend to downregulation in the advanced stage of the disease. The regulation of SPARC seems to be opposite to the markers of tumor burden and of aggressive multiple myeloma phenotype.     

Insulin regulation of glucose and lipid metabolism in massive obesity

Summary Eight obese patients and 12 normal individuals underwent a euglycaemic insulin clamp (20 and 40 mU · m^2–1 · min^–1) along with continuous infusion of 3-³H-glucose and 1-¹⁴C-palmitate and indirect calorimetry. Basal plasma glucose concentration (4.7±0.3 vs 4.4±0.2 mmol/l) was similar in the two groups, whereas hepatic glucose production was slightly higher in obese individuals (1.11±0.06 vs 0.84±0.05 mmol/min) in spite of higher plasma insulin levels (17±2 vs 6±1 mU/l; p<0.01). Insulin inhibition of hepatic glucose production was impaired in obese subjects. Glucose disposal by lean body mass was markedly reduced both at baseline (11.7±1.1 vs 15.6±0.6 mol · kg^–1 · min^–1; p<0.05) and during clamp (15.0±1.1 vs 34.4±2.8 and 26.7±3.9 vs 62.2±2.8 mol · kg^–1 · min^–1; p<0.01) Oxidative (12.2±1.1 vs 17.8±1 and 16.1±1.1 vs 51.1±1.7 mol · kg^–1 · min^–1; p<0.05–0.002) and non-oxidative glucose metabolism (3.9±1.1 vs 15.0±2.8 and 12.8±3.3 vs 38.3±2.2 mol · kg^–1 · min^–1; p<0.01–0.001) were impaired. Basal plasma concentrations of non-esterified fatty acids (635±75 vs 510±71 mol/l) and blood glycerol (129±17 vs 56±5 mol/l; p<0.01) were increased in obese patients. Following hyperinsulinaemia, plasma non-esterified fatty acids (244±79 vs 69±16 and 140±2 vs 36±10 mol/l; p<0.01) and blood glycerol levels (79±20 vs 34±6 and 73±22 vs 29±5 mol/l; p<0.01) remained higher in obese subjects. Baseline non-esterified fatty acid production rate per kg of fat body mass was significantly larger in normal weight subjects (37.7±6.7 vs 14.0±1.8 mol/l; p<0.01) and insulin inhibition was reduced in obese patients (–41±9 vs –74±3 and –53±11 vs –82±3%; p<0.05). Basal plasma non-esterified fatty acid utilization by lean body mass was similar in the two groups (9.8±0.9 vs 8.8±2.0 mol · kg^–1 · min^–1), whereas during clamp it remained higher in obese patients (6.0±1.2 vs 2.8±2.5 and 4.9±1.3 vs 1.5±0.6 mol · kg^–1 · min^–1; p<0.1–0.05). Lipid oxidation was higher in obese individuals in spite of hyperinsulinaemia (3.7±0.3 vs 2.4±0.4 and 2.3±0.4 vs 0.9±0.3 mol · kg^–1 · min^–1; p<0.05– 0.02). An inverse correlation was found between lipid oxidation and glucose oxidation (r=0.82 and 0.93; p<0.001) and glucose utilization (r=0.54 and 0.83; p<0.05–0.001) both in obese and control subjects. A correlation between lipid oxidation and non-oxidative glucose metabolism was present only in normal weight individuals (r=0.75; p<0.01). We conclude that in obesity all tissues (muscles, liver, and adipose tissue) are resistant to insulin action. Insulin resistance involves glucose as well as lipid metabolism.     

Relationship between insulin responses tod-glucose and tol-arginine in women with a history of gestational diabetes

The relationship between insulin responses to glucose and to arginine was studied in non-obese women with previous gestational diabetes (PGD). One group,n=10, had normal glucose tolerance (NGT) by WHO criteria and another,n=8, had impaired glucose tolerance (IGT). A third group of women without PGD,n=12, was also studied. A hyperglycaemic clamp (blood glucose level 11 mM) and an arginine stimulation test (150 mg/kgl-arginine followed by 10 mg/kg · min) were performed on separate days. The ratios of arginine to glucose responses 0–10 min differed: they were 1.00 for non-PGD, 1.29 for NGT and 1.46 for IGT (P<0.02 vs non-PGD). A further difference between groups was the ratio between first- and second-phase glucose-induced insulin secretion, which was significantly decreased in IGT, 0.72, compared with NGT, 0.98 (P<0.01), and non-PGD, 1.05 (P<0.005). However, within each group insulin responses 0–10 min to glucose and arginine were strongly correlated: for NGT (r=0.75,P<0.05), for IGT (r=0.85,P<0.01) and for women without PGD (r=0.69,P<0.05). Insulin sensitivity, as assessed by the M/I ratio, was non-significantly decreased in IGT (0.18±0.03 mg/kg·min per mU/l vs 0.26 ±0.03 in NGT and 0.28±0.03 in non-PGD,P<0.1). Conclusions are: (1) insulin responses to glucose and arginine are linked both in PGD and non-PGD women, but (2) the relative potency of these secretagogues as well as the time-dynamics of glucose-induced insulin secretion may be altered in PGD with IGT.     

In situ binding of islet hormones in the isolated perfused rat pancreas: evidence for local high concentrations of islet hormones via the islet-acinar axis

Summary Insulin and somatostatin reportedly affect pancreatic acinar cell function via specific receptor binding. Theoretically peri-insular levels depend on the islet-acinar portal system, but the actual hormone levels have never been demonstrated. Rat pancreata were perfused anterogradely or retrogradely with ¹²⁵I-insulin, -somatostatin, or -glucagon (each, 10^–11 mol/l). Tracer binding was determined from differences between influx and efflux radioactivity. Saturable binding was observed for insulin and somatostatin, but not for glucagon. Binding in the absence of unlabelled peptides was significantly higher during retrograde perfusion than during anterograde perfusion for insulin (25.9±2.6 vs 16.0±2.1%, mean±SD; each, n=4; p<0.001) and somatostatin (18.4±2.0 vs 13.6±1.2%; each, n=3; p<0.05). Non-specific binding was similar in both directions. These findings are attributable to endogenous hormones acting as unlabelled ligands competing with the tracers during anterograde perfusion. This conclusion was supported by the demonstration that endogenous insulin stimulation by d-glucose, but not by l-glucose, caused a decrease in labelled insulin binding only during anterograde perfusion. Displacement curves obtained during retrograde perfusion showed that interstitial concentrations of insulin and somatostatin were 7.5×10^–9 and 1.1×10^–9 mol/l, respectively. Thus, the exocrine pancreas is indeed exposed to locally high concentrations of islet hormones.Abbreviations SS Somatostatin - TCA trichloroacetic acid     

Clinical features,laboratory characteristics and outcomes of patients with renal versus cardiac light chain amyloidosis

This study evaluated the differences in clinical features of 1077 newly diagnosed AL amyloidosis patients with renal involvement (n = 229, 21%), both cardiac and renal involvement (n = 443, 41%) and cardiac involvement (n = 405, 38%). Significant differences in dFLC (difference in involved and uninvolved light chains) were noted (renal, both, cardiac median: 83, 234 and 349 mg/l, P < 0.001). The proportion of patients with ≥ 10% bone marrow plasma cells (BMPCs) was lowest in renal only patients: 44%, 57%, 64%, respectively, P < 0.001. In a multivariate linear regression model incorporating organ involvement type and BMPCs ≥10%, organ involvement was a significant predictor of dFLC (P < 0.001). Median overall survival (OS) across the three groups was 83 vs. 19 vs. 16 months (P < 0.001) in patients not undergoing transplant and 5-year OS in patients undergoing transplant was 90% vs. 75% vs. 64% (P = 0.007), respectively. In conclusion, renal involvement alone or renal + cardiac involvement in AL amyloidosis is associated with lower circulating light chain burden, which cannot be fully explained by BMPC burden alone. Increased sensitivity of the kidney to light chains, given significant interactions with the renal tubular system and secretion of modified light chain products may play a role in pathogenesis of renal AL amyloidosis and warrants further investigation.     

Glucose tolerance and plasma insulin response to intravenous glucose infusion and test meal in rats with microencapsulated islet allografts

Summary Albino Oxford rats made diabetic with 75 mg/kg streptozotocin were intraperitoneally transplanted with 2500–2900 alginate-polylysine microencapsulated Lewis islets (n=9, total islet tissue volume 8.0–11.0 l), or a similar volume of non-encapsulated Lewis islets (n=5). All rats with microencapsulated islets became normoglycaemic, and remained normoglycaemic for 5–16 weeks. In rats with non-encapsulated islet grafts, only a temporary decrease in blood glucose was observed, and all were again severely hyperglycaemic at 1 week after implantation. At 5–6 weeks after transplantation, glucose tolerance in rats with microencapsulated islets was tested by intravenous glucose infusion (10 mg/min over 20 min) and test meal administration (n=4). During glucose infusion, maximum glucose levels were 13.0±0.4 mmol/l in rats with microcapsules and 8.9±0.4 mmol/l in healthy control rats (p<0.01). Concomitant maximum plasma insulin levels were 215±17 pmol/l in rats with microcapsules and 715±85 pmol/l in controls (p<0.001). After the test meal, maximum blood glucose was 10.6±0.9 mmol/l in rats with microcapsules and 6.2±0.1 mmol/l in controls (p<0.001), with concomitant maximum plasma insulin levels of 247±11 pmol/l and 586±59 pmol/l, respectively (p<0.001). In conclusion, although the glucose tolerance is impaired and plasma insulin responses to intravenous glucose-load and test-meal are reduced, the alginate-polylysine membrane does provide adequate immunoisolation for the prolongation of allograft survival, resulting in prolonged normoglycaemia in streptozotocin diabetic rats.