Prediabetes is more than a pre-disease: additional evidences supporting the importance of its early diagnosis and appropriate treatment

AIM

To identify Prediabetes (PreD) as early and serious diabetes step using clinical-biochemical characteristics in the population of the Primary Prevention Diabetes Buenos Aires (PPDBA) study.

METHODS

PPDBA Study evaluated benefits of adopting healthy lifestyles to prevent T2D. It recruited people 45-75 years of age with PreD (impaired fasting glycaemia [IFG], impaired glucose tolerance [IGT] or both, American Diabetes Association criteria), using an opportunistic approach. They completed a FINDRISC questionnaire, and those with a score ≥13 points were invited to participate. When they accepted, we performed an oral glucose tolerance test (OGTT) with a complete lipid profile and HbA1c while physicians completed a clinical history. We recruited 367 persons, and depending on OGTT results, the sample was divided into normals (NGT), PreD, or with diabetes (last one was excluded in our analysis). Data were statistically analyzed using parametric and nonparametric tests and logistic regression to identify parameters associated with PreD.

RESULTS

From the recruited (n = 367) 47.7% have NGT, 48.5% PreD and 3.8% unknown T2D (excluded). People with PreD were significantly older, with a higher percentage of overweight/obesity, BMI, and larger waist circumference than NGT. They also showed significantly higher fasting and 2 h post glucose load, HbA1c, and triglyceride levels. No significant differences were recorded in the blood pressure, lipid profile though both groups had abnormally high LDL-c values. They also had a larger percentage of TG/HDL-c ratios (insulin resistance indicator) (55% vs. 37.5%). Logistic regression analysis showed that PreD was significant associated with age, waist circumference, and triglyceride above target values.

CONCLUSION

Our findings showed that clinical and biochemical parameters were significantly different between people with PreD and those with NGT. This evidence supports the concept that PreD is a serious dysfunction, which should be early diagnosed and treated properly to prevent its transition to T2D and its complications.

Effects of islet neogenesis associated protein depend on vascular endothelial growth factor gene expression modulated by hypoxia-inducible factor 1-alpha

BACKGROUND

Pharmacology has provided efficient tools to improve insulin effect/secretion but the decrease in β-cell mass remains elusive. INGAP-PP could provide a therapeutic alternative to meet that challenge.

AIM

To further understand the mechanism that links INGAP-PP effects upon β-cell mass and function with islet angiogenesis.

METHODOLOGY

Normal male Wistar rats were divided into 2 groups and injected with a single dose of 100 mg/Kg suramin or saline. Both groups were divided into 2 subgroups that received daily doses of 2 mg/kg INGAP-PP or saline for ten days. Plasma glucose, triacylglycerol, TBARS, and insulin levels were measured. Pancreas immunomorphometric analyses were also performed. Pancreatic islets were isolated to measure glucose-stimulated insulin secretion (GSIS). Specific islet mRNA levels were studied by qRT-PCR. Statistical analysis was done using ANOVA.

RESULTS

No differences were recorded in body weight, food intake, or any other plasma parameter measured in all groups. Islets from INGAP-PP-treated rats significantly increased GSIS, β-cell mass, and mRNA levels of Bcl-2, Ngn-3, VEGF-A, VEGF-R2, CD31, Ang1 and Ang2, Laminin β-1, and Integrin β-1, and decreased mRNA levels of Caspase-8, Bad, and Bax. Islets from suramin-treated rats showed significant opposite effects, but INGAPP-PP administration rescued most of the suramin effects in animals treated with both compounds.

CONCLUSION

Our results reinforce the concept that INGAP-PP enhances insulin secretion and β-cell mass, acting through PI3K/Akt/mTOR pathways and simultaneously activating angiogenesis through HIF-1α-mediated VEGF-A secretion. Therefore, INGAP-PP might be a suitable antidiabetic agent able to overcome two major alterations present in T2D.

Cardiovascular disease management in people with diabetes outside North America and Western Europe in 2006 and 2015

AIM

Optimal treatment of cardiovascular disease is essential to decrease mortality among people with diabetes, but information is limited on how actual treatment relates to guidelines. We analysed changes in therapeutic approaches to anti-hypertensive and lipid-lowering medications in people with Type 2 diabetes from 2006 and 2015.

METHODS

Summary data from clinical services in seven countries outside North America and Western Europe were collected for 39 684 people. Each site summarized individual-level data from outpatient medical records for 2006 and 2015. Data included: demographic information, blood pressure (BP), total cholesterol levels and percentage of people taking statins, anti-hypertensive medication (angiotensin-converting enzyme inhibitors, calcium channel blockers, angiotensin II receptor blockers, thiazide diuretics) and antiplatelet drugs.

RESULTS

From 2006 to 2015, mean cholesterol levels decreased in six of eight sites (range: -0.5 to -0.2), whereas the proportion with BP levels > 140/90 mmHg increased in seven of eight sites. Decreases in cholesterol paralleled increases in statin use (range: 3.1 to 47.0 percentage points). Overall, utilization of anti-hypertensive medication did not change. However, there was an increase in the use of angiotensin II receptor blockers and a decrease in angiotensin-converting enzyme inhibitors. The percentage of individuals receiving calcium channel blockers and aspirin remained unchanged.

CONCLUSIONS

Our findings indicate that control of cholesterol levels improved and coincided with increased use of statins. The percentage of people with BP > 140/90 mmHg was higher in 2015 than in 2006. Hypertension treatment shifted from using angiotensin-converting enzyme inhibitors to angiotensin II receptor blockers. Despite the potentially greater tolerability of angiotensin II receptor blockers, there was no associated improvement in BP levels.

Registry of people with diabetes in three Latin American countries: a suitable approach to evaluate the quality of health care provided to people with type 2 diabetes

AIMS

To implement a patient registry and collect data related to the care provided to people with type 2 diabetes in six specialized centers of three Latin American countries, measure the quality of such care using a standardized form (QUALIDIAB) that collects information on different quality of care indicators, and analyze the potential of collecting this information for improving quality of care and conducting clinical research.

METHODS

We collected data on clinical, metabolic and therapeutic indicators, micro- and macrovascular complications, rate of use of diagnostic and therapeutic elements and hospitalization of patients with type 2 diabetes in six diabetes centers, four in Argentina and one each in Colombia and Peru.

RESULTS

We analyzed 1157 records from patients with type 2 diabetes (Argentina, 668; Colombia, 220; Peru, 269); 39 records were discarded because of data entry errors or inconsistencies. The data demonstrated frequency performance deficiencies in several procedures, including foot and ocular fundus examination and various cardiovascular screening tests. In contrast, HbA1c and cardiovascular risk factor assessments were performed with a greater frequency than recommended by international guidelines. Management of insulin therapy was sub-optimal, and deficiencies were also noted among diabetes education indicators.

CONCLUSIONS

Patient registry was successfully implemented in these clinics following an interactive educational program. The data obtained provide useful information as to deficiencies in care and may be used to guide quality of care improvement efforts.

Clinical, metabolic and psychological outcomes and treatment costs of a prospective randomized trial based on different educational strategies to improve diabetes care (PRODIACOR)

AIM

To evaluate the effect of system interventions (formalized data collection and 100% coverage of medications and supplies) combined with physician and/or patient education on therapeutic indicators and costs in Type 2 diabetes.

METHODS

This was a randomized 2 × 2 design in public health, social security or private prepaid primary care clinics in Corrientes, Argentina. Thirty-six general practitioners and 468 adults with Type 2 diabetes participated. Patients of nine participating physicians were selected randomly and assigned to one of four structured group education programmes (117 patients each): control (group 1), physician education (group 2), patient education (group 3), and both physician education and patient education (group 4), with identical system interventions in all four groups. Outcome measures included HbA(1c), BMI, blood pressure, fasting glucose, lipid profile, drug consumption, resource use and patient well-being at baseline and every 6 months up to 42 months.

RESULTS

HbA(1c) decreased significantly from 4 mmol/mol to 10 mmol/mol by 42 months (P < 0.05); the largest and more consistent decrease was in the groups where patients and physicians were educated. Blood pressure and triglycerides decreased significantly in all groups; the largest changes were recorded in the combined education group. The World Health Organization-5 Lowe score showed significant improvements, without differences among groups. The lowest treatment cost was seen in the combined education group.

CONCLUSIONS

In a primary care setting, educational interventions combined with comprehensive care coverage resulted in long-term improvement in clinical, metabolic and psychological outcomes at the best cost-effectiveness ratio.

Real-world factors affecting adherence to insulin therapy in patients with Type 1 or Type 2 diabetes mellitus: a systematic review

AIMS

To identify real-world factors affecting adherence to insulin therapy in patients with Type 1 or Type 2 diabetes mellitus.

METHODS

A literature search was conducted in PubMed and EMBASE in November 2011 to identify studies reporting factors associated with adherence/non-adherence to insulin therapy in adults with Type 1 or Type 2 diabetes.

RESULTS

Seventeen studies were identified; six used self-reported measures and 11 used calculated measures of adherence. Most (13/17) were conducted exclusively in the USA. Four categories of factors associated with non-adherence were identified: predictive factors for non-adherence, patient-perceived barriers to adherence, type of delivery device and cost of medication. For predictive factors and patient-perceived barriers, only age, female sex and travelling were associated with non-adherence in more than one study. Fear of injections and embarrassment of injecting in public were also cited as reasons for non-adherence. Conversely, adherence was improved by initiating therapy with, or switching to, a pen device (in four studies), and by changing to an insurance scheme that lowered the financial burden on patients (in two studies).

CONCLUSIONS

Adherence to insulin therapy is generally poor. Few factors or patient-perceived barriers were consistently identified as predictive for non-adherence, although findings collectively suggest that a more flexible regimen may improve adherence. Switching to a pen device and reducing patient co-payments appear to improve adherence. Further real-world studies are warranted, especially in countries other than the USA, to identify factors associated with non-adherence and enable development of strategies to improve adherence to insulin therapy.

Patients' education, and its impact on care outcomes, resource consumption and working conditions: data from the International Diabetes Management Practices Study (IDMPS)

AIM

To evaluate the impact of diabetes education provided to patients with type 2 diabetes mellitus (T2DM) in non-controlled studies ("real-world conditions") on quality of care, resource consumption and conditions of employment.

METHODS

This cross-sectional study and longitudinal follow-up describe the data (demographic and socioeconomic profiles, clinical characteristics, treatment of hyperglycaemia and associated cardiovascular risk factors, resource consumption) collected during the second phase (2006) of the International Diabetes Management Practices Study (IDMPS). Patients received diabetes education directly from the practice nurse, dietitian or educator, or were referred to ad hoc group-education programmes; all programmes emphasized healthy lifestyle changes, self-care and active participation in disease control and treatment. Educated vs non-educated T2DM patients (n=5692 in each group), paired by age, gender and diabetes duration, were randomly recruited for the IDMPS by participating primary-care physicians from 27 countries in Eastern Europe, Asia, Latin America and Africa. Outcome measures included clinical (body weight, height, waist circumference, blood pressure, foot evaluation), metabolic (HbA(1c) levels, blood lipid profile) and biochemical control measures. Treatment goals were defined according to American Diabetes Association guidelines.

RESULTS

T2DM patients' education significantly improved the percentage of patients achieving target values set by international guidelines. Educated patients increased their insulin use and self-care performance, had a lower rate of chronic complications and a modest increase in cost of care, and probably higher salaries and slightly better productivity.

CONCLUSION

Diabetes education is an efficient tool for improving care outcomes without having a major impact on healthcare costs.

A quantitative assessment of patient barriers to insulin

AIM

To assess diabetes treatment preferences with a focus on patient barriers to insulin treatment.

MATERIALS AND METHODS

A questionnaire using indirect and direct methods was administered as part of the International Diabetes Management Practices Study (IDMPS). Discrete choice modelling was used to assess how product attributes influence patients' preferences for diabetes treatment. A multinomial logit model was used to find the odds ratio for each parameter, representing the probability of selecting a chosen alternative given a choice set. This allowed for the derivation of relative attribute importance, an indication of how influential product attributes are in the respondents' choices.

RESULTS

The IDMPS questionnaire was administered to 14,033 individuals with diabetes in 18 countries. The majority of respondents were women (53%) and had Type 2 diabetes mellitus (T2DM; 85%). Across subgroups, administration (i.e. oral vs. injection) was a driver of preference. Patient preferences varied according to diabetes type; individuals with T2DM assigned much higher relative importance to administration than those with Type 1 diabetes mellitus (T1DM; 30.86% vs. 4.99%; p<0.0001). Individuals with T2DM treated with insulin placed less importance on administration than insulin-naïve T2DM patients (3.09% vs. 47.48%; p<0.0001). Diabetes education also had a significant effect on the priority given to administration between T2DM patients who received diabetes training and those who did not (28.21% vs. 33.68%, respectively; p<0.0001).

CONCLUSION

The insulin barriers perceived by patients with diabetes evolved with their disease experience. While administration was the primary preference driver for insulin-naïve patients, patients were increasingly concerned with more clinically relevant barriers as they gained experience with insulin. This finding suggests that patients using insulin understand the importance of achieving an optimal balance between safety and efficacy.

Resource use associated with type 2 diabetes in Asia, Latin America, the Middle East and Africa: results from the International Diabetes Management Practices Study (IDMPS)

AIMS

To estimate diabetes-related resource use and investigate its predictors among individuals with type 2 diabetes in 24 countries in Asia, Latin America, the Middle East and Africa.

METHODS

Cross-sectional observational data on diabetes-related resource use were collected from 15,016 individuals with type 2 diabetes within the second wave of International Diabetes Management Practices Study. Mean (SD) annual quantities were determined and predictors of diabetes-related hospitalisations, inpatient days, emergency room visits and absenteeism were investigated using negative binomial regression.

RESULTS

Patients in Asia (n = 4678), Latin America (n = 6090) and the Middle East and Africa (n = 4248) made a mean (SD) of 3.4 (6.9), 5.4 (6.7) and 2.5 (4.4) General Practitioner visits per year. The mean (SD) number of inpatient days amounted to 3.8 (18.1), 2.2 (13.9) and 2.6 (13.5) per year. Results of the regression analysis showed the major influence of diabetes-related complications and inadequate glycaemic control on resource use. The expected annual rate of hospitalisation of patients with macrovascular complications compared with those without was 4.7 times greater in Asia [incidence rate ratio (IRR) = 4.7, 95% CI: 2.8-7.8, n = 2551], 5.4 times greater in Latin America (IRR = 5.4, 95% CI: 3.0-9.8, n = 3228) and 4.4 times greater in the Middle East and Africa (IRR = 4.4, 95% CI: 2.8-6.9, n = 2630).

CONCLUSIONS

Micro- and macrovascular complications and inadequate glycaemic control are significant predictors of resource use in people with type 2 diabetes of developing countries. This knowledge confirms the health economic importance of early diagnosis of diabetes, education of patients and glycaemic control.

Islet adaptive changes to fructose-induced insulin resistance: beta-cell mass, glucokinase, glucose metabolism, and insulin secretion

Beta-cell mass, hexokinase/glucokinase (HK/GK) activity, glucose metabolism and insulin secretion were studied in the islets of rats with fructose-induced insulin resistance (IR). Normal male Wistar rats were fed a standard commercial diet and water without (control, C) or with 10% fructose-rich diet (FRD) for 3 weeks. Blood glucose (strips), triglyceride (commercial kit), and insulin (RIA) levels were measured at the time of death. Glucose-induced insulin release, glucose metabolism ((14)CO(2) and (3)H(2)O production from D-[U-(14)C]- and D-[5-(3)H]-glucose) and HK/GK activity (G-6-P production), transcription (RT-PCR), protein expression (Western blot), and cellular compartmentalization were measured in isolated islets (collagenase digestion). FRD rats presented normoglycemia but impaired glucose tolerance, hypertriglyceridemia, hyperinsulinemia, and increased HOMA-IR index. In these rats, beta-cell mass decreased significantly by 33%, with a 44% increase in the percentage of apoptotic cells. Glucose-induced insulin release and islet glucose metabolism were higher in FRD rats. While GK activity (total and cytosolic fraction) and protein expression were significantly higher in FRD islets, HK showed no change in any of these parameters. Our results demonstrate that the changes induced by dietary-induced IR upon beta-cell function and mass are strongly conditional on the nutrient model used. In our model (intact animals with impaired glucose tolerance), GK activity increases through mechanisms previously shown only in vitro or under highly hyperglycemic conditions. Such an increase plays a pivotal role in the adaptive increased release of insulin in response to IR, even in the presence of marked beta-cell mass reduction.

Abdominal adipose tissue: early metabolic dysfunction associated to insulin resistance and oxidative stress induced by an unbalanced diet

The possible contribution of early changes in lipid composition, function, and antioxidant status of abdominal adipose tissue (AAT) induced by a fructose-rich diet (FRD) to the development of insulin resistance (IR) and oxidative stress (OS) was studied. Wistar rats were fed with a commercial diet with (FRD) or without 10% fructose in the drinking water for 3 weeks. The glucose (G), triglyceride (TG), and insulin (I) plasma levels, and the activity of antioxidant enzymes, lyposoluble antioxidants, total glutathione (GSH), lipid peroxidation as TBARS, fatty acid (FA) composition of AAT-TG as well as their release by incubated pieces of AAT were measured. Rats fed with a FRD have significantly higher plasma levels of G, TG, and I. Their AAT showed a marked increase in content and ratios of saturated to monounsaturated and polyunsaturated FAs, TBARS, and catalase, GSH-transferase and GSH-reductase, together with a decrease in superoxide dismutase and GSH-peroxidase activity, and total GSH, alpha-tocopherol, beta-carotene and lycopene content. Incubated AAT from FRD released in vitro higher amount of free fatty acids (FFAs) with higher ratios of saturated to monounsaturated and polyunsaturated FAs. Our data suggest that FRD induced an early prooxidative state and metabolic dysfunction in AAT that would favor the overall development of IR and OS and further development of pancreatic beta-cell failure; therefore, its early control would represent an appropriate strategy to prevent alterations such as the development of type 2 diabetes.

PRODIACOR: A patient-centered treatment program for type 2 diabetes and associated cardiovascular risk factors in the city of Corrientes, Argentina

OBJECTIVE

To implement a controlled clinical trial (PRODIACOR) in a primary care setting designed 1) to improve type 2 diabetes care and 2) to collect cost data in order to be able to measure cost-effectiveness of three system interventions (checkbook of indicated procedures, patient/provider feedback and complete coverage of medications and supplies) and physician and/or patient education to improve psychological, clinical, metabolic and therapeutic indicators. All three Argentinean health subsectors (public health, social security and the private, prepaid system) are participants in the study. Patients of participating physicians were randomly selected and assigned to one of four groups: control, provider education, patient education, and provider/patient education; the system interventions were provided to all four groups.

BASELINE RESULTS

Mean BMI was 29.8 kg/m(2); most subjects had blood pressure, fasting glucose and total cholesterol above targets recommended by international standards. Only 1% had had microalbuminuria measured, 57% performed glucose self-monitoring, 37% had had an eye examination and 31% a foot examination in the preceding year. Ten percent, 26% and 73% of people with hyperglycemia, hypertension and dyslipidemia, respectively, were not on medications. Most patients treated with either insulin or oral antidiabetic agents were on monotherapy as were those treated for hypertension and dyslipidemia. WHO-5 questionnaire scores indicated that 13% of the subjects needed psychological intervention.

CONCLUSIONS

Baseline data show multiple deficiencies in the process and outcomes of care that could be targeted and improved by PRODIACOR intervention.

PROPAT: a study to improve the quality and reduce the cost of diabetes care

OBJECTIVE

In PROPAT we implemented an integrated approach to diabetes care designed to improve the quality and reduce the cost of care.

STUDY DESIGN AND METHODS

PROPAT was a case-control study matching patients by age and gender (diabetes:control ratio 1:2) within IOMA, a public employment-based health maintenance organization (HMO) of the Province of Buenos Aires, Argentina. Costs were evaluated using prevalence data from an HMO perspective. We currently report clinical and biochemical data and costs from the first 297 patients enrolled who completed 1 year in PROPAT, and compare them with those derived from control patients.

RESULTS

All recommended practices recorded as care provided at baseline increased significantly 1 year after implementing PROPAT, with a parallel significant improvement in several clinical and biochemical parameters, and markedly lower total annual per capita costs.

CONCLUSIONS

These results demonstrate that the implementation of a comprehensive diabetes care program can simultaneously improve quality while reducing costs.

Enhanced expression of hexokinase I in pancreatic islets induced by sucrose administration

Administration of a sucrose-rich diet (SRD) to normal hamsters induces an insulin-resistant state and a significant increase of insulin secretion and beta-cell mass. Islets isolated from these animals had a marked increase in glucose metabolism and glucose-induced insulin secretion, at both low and high glucose concentrations. They also presented increased hexokinase (HK) activity, without measurable changes in glucokinase (GK) activity. In this study we measured HK and GK activity in homogenates of islets isolated from normal control and SRD-fed hamsters, as well as in their particulate and cytosolic fractions. We also measured transcription rate (mRNA by reverse transcriptase PCR) and expression levels (Western blotting) of both enzymes in these islets. We found an increase in HK activity and expression levels, without measurable changes in HK mRNA level in SRD-fed animals. Whereas a similar GK activity was measured in homogenates of islets isolated from both groups, such activity was significantly higher in the cytosolic fraction of SRD islets. On the other hand, GK transcription rate and expression level were similar in both experimental groups. Our results suggest that the increased beta-cell secretory response to low glucose can be partly ascribed to an increased activity of islet HK consecutive to an enhanced expression of the enzyme, while the enhanced response to high glucose could be due to changes in GK compartmentalization.

Plasma Membrane Calcium Pump Activity in Rat Pancreatic Islets: An Accurate Method to Measure its Calcium-Dependent Modulation

The aim of this study was to quantify the glucose modulation of the plasma membrane calcium pump (PMCA) function in rat pancreatic islets. Ca2+-ATPase activity and levels of phosphorylated PMCA intermediates both transiently declined to a minimum in response to stimulation by glucose. Strictly dependent on Ca2+ concentration, this inhibitory effect was fully expressed at physiological concentrations of the cation (less than 0.5 muM), then progressively diminished at higher concentrations. These results, together with those previously reported on the effects of insulin secretagogues and blockers on the activity, expression and cellular distribution of the PMCA, support the concept that the PMCA plays a key role in the regulation of Ca2+ signaling and insulin secretion in pancreatic islets.

Islet neogenesis: an apparent key component of long-term pancreas adaptation to increased insulin demand

This study aimed to determine the relative importance of different functional and morphological pancreatic changes induced by the chronic administration of a sucrose-rich diet (SRD) to maintain normal glucose homeostasis. Male Wistar rats were fed either sucrose (SRD) or starch (CD) for 6 and 12 months. At both periods, serum glucose and triacylglycerol levels were significantly higher (P<0.05; paired and unpaired Student's t-test) in SRD rats. Serum insulin levels were significantly lower in SRD only at 12 months. At 6 months, the insulin secretion dose-response curve in SRD rats showed a shift to the left that was no longer observed at 12 months, when SRD islets decreased their response to 16 mM glucose. At 6 months, SRD rats showed a significant increase in beta-cell volume density (Vvi) and islet cell replication rate, together with a decrease in beta-cell apoptotic rate. Changes were not detected in the percentage of PDX-1- and islet neogenesis associated protein (INGAP)-positive cells. Conversely, at 12 months, there was a significant decrease in beta-cell Vvi and in the percentage of PDX-1-positive cells; the islet cell replication rate was not modified, and the number of apoptotic beta-cells increased significantly. No signs of increased neogenesis or INGAP-positive cells were recorded at any period in SRD rats. Our results show that SRD rats are unable to develop functional and morphological pancreatic reactive changes sufficient to maintain normal glucose and triacylglycerol levels for a long period. Such failure could be ascribed to their inability to increase the rate of neogenesis and of INGAP production.

Hospitalization and re-hospitalization of people with and without diabetes in La Plata, Argentina: comparison of their clinical characteristics and costs

OBJECTIVE

To examine the prevalence, characteristics, and costs of hospitalization and re-hospitalization of diabetic and non-diabetic patients in La Plata, Argentina, and to compare the data with those of developed countries.

RESEARCH DESIGN AND METHODS

We studied all in-hospital registries of diabetic patients enrolled in a health maintenance organization of the Province of Buenos Aires (IOMA, November 1996). For each diabetic patient (127 persons), the characteristics of two other hospitalized non-diabetic patients matched by age and gender were simultaneously recorded.

RESULTS

Of the 2200 recorded hospitalizations, 5.8% were for diabetic patients, accounting for 10.5% of the hospitalization cost. Cardiovascular diseases were the major cause of hospitalization in both groups. The per capita hospitalization cost of diabetic patients was significantly higher: 1628.5+/-1754.0 US dollars versus 833+/-842 US dollars; P=0.00002. Percent re-hospitalizations were five and a half times higher in diabetic patients (P=0.0001), and significantly associated with history of severe episodes of acute (odds ratio: 3.61; 95% CI: 1.11-11.70; P=0.03) and chronic (odds ratio: 4.26; 95% CI: 1.60-11.29; P=0.004) complications.

CONCLUSIONS

The combination of higher and longer hospitalization rates and frequent re-hospitalizations resulted in increased costs for our diabetic population. Implementation of care programs based on education (for physicians and patients) could effectively decrease current and future costs of the disease.

Expression of islet neogenesis-associated protein in islets of normal hamsters

The aim of the present study was to test the possible presence and expression of islet neogenesis-associated protein (INGAP) in islet cells of normal adult hamsters. Pancreata from normal male Syrian hamsters were removed to perform the following studies. (i) Western blot analysis using the cytosolic fraction from homogenates of isolated islets, exocrine tIssue and whole pancreas, and rabbit INGAP-specific antibody. (ii) Immunohistochemical identification of INGAP-positive cells in fixed sections of intact pancreata, fresh and 72 h cultured islets (isolated by collagenase digestion), and smears of exocrine pancreatic cells, using the same INGAP-specific antibody and streptavidin-biotin complex. (iii) RT-PCR using total RNA extracted from isolated islets and from exocrine tIssue as template, and a specific pair of primers. (iv) Control of the sequence of the PCR products. INGAP protein was identified by Western blot in the cytosolic fraction of homogenates from fresh isolated islets, exocrine cells and whole fresh pancreas. INGAP-immunopositive cells were observed in duct, exocrine and islet cells in either fixed intact or digested pancreatic tIssue. INGAP mRNA was identified in samples of total RNA from fresh and cultured isolated islets and from exocrine cells. Our data demonstrate that INGAP is present and expressed in islets and in exocrine pancreatic cells of normal hamsters. The ubiquitous localization of INGAP suggests its possible role in the physiological process of islet growth and its protective effect upon streptozotocin-induced diabetes.

Pancreatic duodenal homeobox-1 and islet neogenesis-associated protein: a possible combined marker of activateable pancreatic cell precursors

The aim of this work was to study the possible relationship between pancreatic duodenal homeobox-1 (Pdx-1) and islet neogenesis-associated protein (INGAP) during induced islet neogenesis. Pregnant hamsters were fed with (S) and without (C) sucrose, and glycemia, insulin secretion in vitro, and pancreas immunomorphometric parameters were measured in their 7-day-old offspring. S offspring had significantly lower glycemic levels than C animals. Insulin release in response to increasing glucose concentrations in the incubation medium (2-16 mM glucose) did not increase in pancreata from either C or S offspring. However, pancreata from S offspring released more insulin than those from C animals. In S offspring, beta-cell mass, beta-cell replication rate and islet neogenesis increased significantly, with a simultaneous decrease in beta-cell apoptotic rate. INGAP- and Pdx-1-positive cell mass also increased in the islets and among acinar and duct cells. We found two subpopulations of Pdx-1 cells: INGAP-positive and INGAP-negative. Pdx-1/INGAP-positive cells did not stain with insulin, glucagon, somatostatin, pancreatic polypeptide, or neurogenin 3 antibodies. The increment of Pdx-1/INGAP-positive cells represented the major contribution to the Pdx-1 cell mass increase. Such increments varied among pancreas subsectors: ductal>insular>extrainsular. Our results suggested that INGAP participates in the regulation of islet neogenesis, and Pdx-1/INGAP-positive cells represent a new stem cell subpopulation at an early stage of development, highly activateable in neogenesis.

Mechanisms involved in the beta-cell mass increase induced by chronic sucrose feeding to normal rats

The aim of the present study was to clarify the mechanisms by which a sucrose-rich diet (SRD) produces an increase in the pancreatic beta-cell mass in the rat. Normal Wistar rats were fed for 30 weeks either an SRD (SRD rats; 63% wt/wt), or the same diet but with starch instead of sucrose in the same proportion (CD rats). We studied body weight, serum glucose and triacylglycerol levels, endocrine tissue and beta-cell mass, beta-cell replication rate (proliferating cell nuclear antigen; PCNA), islet neogenesis (cytokeratin immunostaining) and beta-cell apoptosis (propidium iodide). Body weight (g) recorded in the SRD rats was significantly (P<0.05) larger than that of the CD group (556.0+/-8.3 vs 470.0+/-13.1). Both serum glucose and triacylglycerol levels (mmol/l) were also significantly higher (P<0.05) in SRD than in CD rats (serum glucose, 8.11+/-0.14 vs 6.62+/-0.17; triacylglycerol, 1.57+/-0.18 vs 0.47+/-0.04). The number of pancreatic islets per unit area increased significantly (P<0.05) in SRD rats (3.29+/-0.1 vs 2.01+/-0.2). A significant increment (2.6 times) in the mass of endocrine tissue was detected in SRD animals, mainly due to an increase in the beta-cell mass (P=0.0025). The islet cell replication rate, measured as the percentage of PCNA-labelled beta cells increased 6.8 times in SRD rats (P<0.03). The number of apoptotic cells in the endocrine pancreas decreased significantly (three times) in the SRD animals (P=0.03). The cytokeratin-positive area did not show significant differences between CD and SRD rats. The increase of beta-cell mass induced by SRD was accomplished by an enhanced replication of beta cells together with a decrease in the rate of beta-cell apoptosis, without any evident participation of islet neogenesis. This pancreatic reaction was unable to maintain serum glucose levels of these rats at the level measured in CD animals.

Expression and cellular distribution pattern of plasma membrane calcium pump isoforms in rat pancreatic islets

This work is aimed at identifying the presence and cellular distribution pattern of plasma membrane calcium pump (PMCA) isoforms in normal rat pancreatic islet. Microsomal fractions of isolated islets and exocrine tissue were analyzed to detect different PMCA isoforms. The cellular distribution pattern of these PMCAs in the islets was also studied in fixed pancreas sections incubated with antibodies against PMCAs and insulin. Antibody 5F10, which reacts with all PMCA variants, showed multiple bands in the blots in the 127-134 kDa region, indicating the presence of several isoforms. Microsomes also reacted positively with specific antibodies for individual PMCA isoforms, generating a band of the expected size. Antibody 5F10 immunocytochemically labeled the plasma cell membrane of both b- and non-b-cells, but predominantly the former. All islet cells were also labeled with antibodies against isoforms 1 and 4, while the antibody reacting with isoform 3 labeled exclusively b-cells. A few b- and non-b-cells were positively labeled with the antibody reacting with PMCA b variant. Negative results were obtained with the antibody against isoform 2. Further studies, together with previous reports on the modulatory effect of insulin secretagogues and blockers upon PMCA activity, may provide evidence of the importance of this particular PMCA expression for islet function under normal and pathological conditions.

Changes induced by sucrose administration on glucose metabolism in pancreatic islets in normal hamsters

We correlated the changes in glucose-induced insulin secretion with those observed in glucose metabolism and hexokinase/glucokinase activity in islets from normal sucrose-fed hamsters. Blood glucose and insulin levels were measured in normal male hamsters fed with (S5) or without (C5) 10% sucrose in the drinking water for 5 weeks. Isolated islets (collagenase digestion) from both groups of animals were used to study insulin secretion, (14)CO(2) and (3)H(2)O production from D-[U-(14)C]-glucose and D-[5-(3)H]-glucose respectively, with 3.3 or 16.7 mM glucose in the medium, and hexokinase/glucokinase activity (fluorometric assay) in islet homogenates. Whereas S5 and C5 animals had comparable normal blood glucose levels, S5 showed higher insulin levels than C5 hamsters (2.3+/-0.1 vs 0.6+/-0.03 ng/ml, P<0.001). Islets from S5 hamsters released significantly more insulin than C5 islets in the presence of low and high glucose (3.3 mM glucose: 0.77+/-0.04 vs 0.20+/-0.06 pg/ng DNA/min, P<0.001; 16.7 mM glucose: 2.77+/-0.12 vs 0.85+/-0.06 pg/ng DNA/min, P<0.001) and produced significantly higher amounts of (14)CO(2) and (3)H(2)O at both glucose concentrations ((14)CO(2): 3.3 mM glucose: 0.27+/-0.01 vs 0.18+/-0.01, P<0.001; 16.7 mM glucose: 1.44+/-0.15 vs 0.96+/-0.08, P<0.02; (3)H(2)O: 3.3 mM glucose: 0.31+/-0.02 vs 0.15+/-0.01, P<0.001; 16.7 mM glucose: 1.46+/-0.20 vs 0.76+/-0.05 pmol glucose/ng DNA/min, P<0.005). The hexokinase K(m) and V(max) values from S5 animals were significantly higher than those from C5 ones (K(m): 100.14+/-7.01 vs 59.90+/- 3.95 microM, P<0.001; V(max): 0.010+/-0.0005 vs 0.008+/- 0.0006 pmol glucose/ng DNA/min, P<0.02). Conversely, the glucokinase K(m) value from S5 animals was significantly lower than in C5 animals (K(m): 15.31+/-2.64 vs 35.01+/-1.65 mM, P<0.001), whereas V(max) figures were within a comparable range in both groups (V(max): 0.048+/-0.009 vs 0.094+/-0.035 pmol glucose/ng DNA/min, not significant). The glucose phosphorylation ratio measured at 1 and 100 mM (hexokinase/glucokinase ratio) was significantly higher in S5 (0.26+/-0.02) than in C5 animals (0.11+/-0.01, P<0.005), and it was attributable to an increase in the hexokinase activity in S5 animals. In conclusion, sucrose administration increased the hexokinase/glucokinase activity ratio in the islets, which would condition the increase in glucose metabolism by beta-cells, and in beta-cell sensitivity and responsiveness to glucose. These results support the concept that increased hexokinase rather than glucokinase activity causes the beta-cell hypersensitivity to glucose, hexokinase being metabolically more active than glucokinase to up-regulate beta-cell function.

[Evaluation of the quality of care for diabetic patients in Latin America]

OBJECTIVE

To make a preliminary diagnosis of the quality of care that individuals with diabetes mellitus (DM) received in participating centers of the QUALIDIAB network in Latin America and the Caribbean, and to assess the potential usefulness of this information as well as the importance of expanding the QUALIDIAB network.

METHODS

A total of 13,513 patient records from the QUALIDIAB network were analyzed, from public and private health care entities and from the Social Security systems of Argentina, Brazil, Chile, Colombia, Paraguay, and Uruguay. The study utilized: 1) quality-of-care indicators based on international reference values, 2) patient information on clinical, biochemical, and therapeutic parameters and on the rate of use of diagnostic and therapeutic materials, 3) a computer database program, and 4) a software program for statistical analysis.

RESULTS

Among the patients studied, about half of them had suffered from diabetes for 5 years or less; this was true both for persons with type 1 diabetes (DM1) and for those with type 2 diabetes (DM2). Of the persons with DM1, 24% of them had a blood glucose level of < 4.4 mmol/L; this was true for 15% of those with DM2. The proportion of persons with a blood glucose level of > 7.7 mmol/L was 41% among those with DM1 and 57% among those with DM2. The frequencies of association between DM2 and other cardiovascular risk factors were: overweight/obesity, 59%; hypertension, 60%; total cholesterol > 5.5 mmol/L, 53%; high-density lipoprotein cholesterol < 1 mmol/L, 32%; triglycerides > 1.7 mmol/L, 45%; and smoking, 13%. Of the people with DM1, 20% of them had a body mass index < 19 kg/m2, probably reflecting deficient metabolic control and inadequate insulin intake. The systematic checking of metabolic control, other cardiovascular risk factors, and chronic DM complications was inadequate in from 3% to 75% of the cases, depending on the specific aspect considered. According to various patient-therapy-education indicators, only some one-quarter to one-half of the studied patients could play an active, effective role in DM control and treatment. Of the persons with DM1, 50% of them were treated with a mixed dose of insulin (NPH + regular insulin), administered in two daily injections in 43% of the cases. Among the patients, 5% of them received one daily insulin injection, and 9% of them received three daily insulin injections. Of the people with DM2, 13% of them treated it only with diet and 14% just with insulin. Among the patients receiving drug treatment, the oral hypoglycemics most used in monotherapy were sulfonylureas (33%), biguanides (9%), and a combination of these two (14%). Fewer than half of the people with diabetes received drug therapy for the associated cardiovascular risk factors. The frequency of patients' macroangiopathic and microangiopathic complications increased with the duration of their disease. Comparing patients who had had diabetes for 5 years or less with those who had had the illness for more than 20 years, the frequency of renal insufficiency and of amputations was around 7 times as great in the latter group; for peripheral neuropathy, it was 2 times as great, and for stroke 1.6 times as great.

CONCLUSIONS

These results show the need to improve the quality of care for diabetic patients in Latin America and the Caribbean, and that QUALIDIAB could help do this. Expanding the QUALIDIAB network will help to more accurately diagnose the quality of that care in the Americas, and it will facilitate interventions aimed at optimizing the care. This, in turn, will improve the quality of life of persons who suffer from diabetes as well as diminish the socioeconomic costs of the disease.

[Evaluation and cost of the health care process of diabetic patients]

The aim of this randomized trial o evaluate the quality and cost of health care provided to people with diabetes in a Public Employment-Based Health Insurance program in La Plata, Argentina. Consequently, 1590 diabetic patients were interviewed and the data obtained were analyzed using univariate and multiple logistic regression. Patients treated without insulin (48%) were significantly older and reported obesity, hypertension, and macroangiopathy more frequently than those treated with insulin. Hospitalization rates were significantly higher in insulin-treated patients. These rates were comparable in people without complications or microangiopathy alone, but increased significantly in patients with macroangiopathy. Many recommended practices were not performed during the preceding year: foot exams (20-30%), referral to ophthalmologist (21-29%), and HbA1c test (60-78%). In contrast, the rate of medical testing and visits was high, even in uncomplicated patients, resulting in an estimated cost of the care 22.7% higher than it would have been if the tests and procedures had been performed as recommended by international guidelines. We conclude that the current care for diabetes is inefficient and expensive; the implementation of data-based guidelines would result in a more effective allocation of resources, thus improving the quality of diabetes care and overall quality of life.

A model educational program for people with type 2 diabetes: a cooperative Latin American implementation study (PEDNID-LA)

OBJECTIVE

To implement an educational program in 10 Latin American countries and to evaluate its effect on the clinical, biochemical, and therapeutic aspects as well as the economic cost of diabetes.

RESEARCH DESIGN AND METHODS

Educators from each participating country were previously trained to implement the educational model. The patient population included 446 individuals with type 2 diabetes; all patients were <65 years of age, did not require insulin for metabolic control, did not have severe complications of diabetes or life-limiting illnesses, and had not previously participated in diabetes education courses. Clinical and therapeutic data and the cost of their pharmacological treatment were collected 6 months before participation in the educational program (-6 months), on entry into the program (time 0), and at 4, 8, and 12 months after initiation of the program.

RESULTS

All parameters measured had improved significantly (P < 0.001) by 1 year: fasting blood glucose (mean +/- SD) 10.6 +/- 3.5 vs. 8.7 +/- 3.0 mmol/l; HbA(1c) 9.0 +/- 2.0 vs. 7.8 +/- 1.6%; body weight 84.6 +/- 14.7 vs. 81.2 +/- 15.2 kg; systolic blood pressure 149.6 +/- 33.6 vs. 142.9 +/- 18.8 mmHg; total cholesterol 6.1 +/- 1.1 vs. 5.4 +/- 1.0 mmol/l; and triglycerides 2.7 +/- 1.8 vs. 2.1 +/- 1.2 mmol/l. At 12 months, the decrease in pharmacotherapy required for control of diabetes, hypertension, and hyperlipidemia represented a 62% decrease in the annual cost of treatment ($107,939.99 vs. $41,106.30 [U.S.]). After deducting the additional cost of glucosuria monitoring ($30,604), there was still a 34% annual savings.

CONCLUSIONS

The beneficial results of this educational model, implemented in 10 Latin American countries, reinforce the value of patient education as an essential part of diabetes care. They also suggest that an educational approach promoting healthy lifestyle habits and patient empowerment is an effective strategy with the potential to decrease the development of complications related to diabetes as well as the socioeconomic costs of the disease.