The complex interplay between clinical and person-centered diabetes outcomes in the two genders.

BACKGROUND: New approaches to cope with clinical and psychosocial aspects of type 2 diabetes (T2DM) are needed; gender influences the complex interplay between clinical and non-clinical factors. We used data from the BENCH-D study to assess gender-differences in terms of clinical and person-centered measures in T2DM. METHODS: Clinical quality of care indicators relative to control of HbA1c, lipid profile, blood pressure, and BMI were derived from electronic medical records. Ten self-administered validated questionnaires (SF-12 Health Survey; WHO-5 well-being index; Problem Areas in Diabetes (PAID) 5, Health Care Climate Questionnaire, Patients Assessment of Chronic Illness Care, Diabetes Empowerment Scale, Diabetes Self-care Activities, Global Satisfaction for Diabetes Treatment, Barriers to Taking Medications, Perceived Social Support) were adopted as person-centered outcomes indicators. RESULTS: Overall, 26 diabetes clinics enrolled 2,335 people (men: 59.7%; women: 40.3%). Lower percentages of women reached HbA1c levels < =7.0% (23.2% vs. 27.8%; p = 0.03), LDL-cholesterol < 100 mg/dl (48.3 vs. 57.8%; p = 0.0005), and BMI <27 Kg/m2 (27.2 vs. 31.6%; p = 0.04) than men. Women had statistically significant poorer scores for physical functioning, psychological well-being, self-care activities dedicated to physical activities, empowerment, diabetes-related distress, satisfaction with treatment, barriers to medication taking, satisfaction with access to chronic care and healthcare communication, and perceived social support than men; 24.8% of women and 8.8% of men had WHO-5 < =28 (likely depression) (p < 0.0001); 67.7% of women and 55.1% of men had PAID-5 > 40 (high levels of diabetes-related distress) (p < 0.0001). At multivariate analysis, factors associated with an increased likelihood of having elevated HbA1c levels (≥8.0%) were different in men and women, e.g. having PAID-5 levels >40 was associated with a higher likelihood of HbA1c ≥8.0% in women (OR = 1.15; 95%CI 1.05-1.25) but not in men (OR = 1.00; 95%CI 0.93-1.08). CONCLUSIONS: In T2DM, women show poorer clinical and person-centered outcomes indicators than men. Diabetes-related distress plays a role as a correlate of metabolic control in women but not in men. The study provides new information about the interplay between clinical and person-centered indicators in men and women which may guide further improvements in diabetes education and support programs.

Clinical and socio-economic correlates of quality of life and treatment satisfaction in patients with type 2 diabetes.

BACKGROUND AND AIM: The aim of the present study was to assess health-related quality of life (HRQOL) and treatment satisfaction in a large, ambulatory based sample of patients with type 2 diabetes. In particular, we evaluated a large array of socio-economic, clinical, and management-related factors, to investigate the extent to which they correlate with physical and psychological well-being, and with treatment satisfaction. METHODS AND RESULTS: Patients were requested to fill in a questionnaire including the SF-36 Health Survey (SF-36), the WHO-Well Being Questionnaire (WBQ), and the WHO-Diabetes Treatment Satisfaction Questionnaire (DTSQ). The analyses were based on multivariate analyses, adjusted for patient clinical and socio-demographic characteristics. The study involved 2499 patients, enrolled in 203 diabetes outpatient clinics. Female gender and diabetes complications were associated with worse physical and psychological well-being, while socioeconomic variables were mainly related to general well-being. The perceived frequency of hyperglycemic episodes was negatively associated with all the dimensions explored. Treatment satisfaction was inversely related to female gender, insulin treatment, perceived frequency of hyperglycemic episodes and diabetes complications. Blood glucose self-monitoring, and among patients treated with insulin, self-management of insulin doses and the use of pen for insulin injections, were associated with higher levels of satisfaction. Finally, higher levels of satisfaction were associated with a better perception of physical and psychological well-being. CONCLUSIONS: Health related quality of life and treatment satisfaction are associated with each other and are both affected by a complex interplay between clinical and socio-economic variables. Some negative aspects, mainly associated with insulin treatment and poor perceived metabolic control, can be attenuated by a deeper involvement of the patients in the management of the disease.

The common -866G/A polymorphism in the promoter region of the UCP-2 gene is associated with reduced risk of type 2 diabetes in Caucasians from Italy.

Uncoupling protein-2 (UCP2) regulates insulin secretion and may play an important role in linking obesity to type 2 diabetes (T2D). Previous studies of the role of the UCP2 promoter -866G/A single nucleotide polymorphisms (SNP) in T2D have given opposite results. We tested the distribution of the -866G/A SNP in 746 T2D patients and 327 healthy unrelated Caucasians from Italy. We also tested for an effect of the P12A variant of the peroxisomal proliferator-activated receptor-gamma 2 (PPAR gamma 2) gene on diabetes risk given by the UCP2 SNP. Compared with -866G/G carriers, a progressively reduced (P = 0.01) risk of T2D was observed in -866G/A and -866A/A subjects, with the latter showing an approximately 50% risk reduction [odd ratio (OR), 0.51; 95% confidence interval (CI), 0.3-0.8; P = 0.003]. Conversely, the -866G/G genotype was associated with increased risk (OR, 1.31; 95% CI, 1.01-1.71). Overall, the population risk attributable to the UCP2 -866G/G genotype was about 12%. After stratifying for the PPAR gamma 2 polymorphism, the increased risk conferred by the UCP2 G/G genotype was still evident among P12/P12 homozygous subjects (n = 801; OR, 1.38; 95% CI, 1.04-1.83), but seemed to disappear among the X12/A12 subjects (i.e. P12/A12 heterozygous or A12/A12 homozygous subjects; n = 137; OR, 0.87; 95% CI, 0.40-1.91). Whether this apparent difference is entirely due to the different number of carriers of the two PPAR gamma 2 genotypes is a likely possibility that deserves deeper investigation. In conclusion, in our population, the -866G/A SNP is associated with T2D. Additional studies in larger samples are needed to investigate the possibility of a concomitant effect of modifier genes such as PPAR gamma 2.

Novel strategies for the pharmacological management of type 2 diabetes.

Type 2 diabetes is characterized by high concentrations of glucose in the blood, which is caused by decreased secretion of insulin from the pancreas and decreased insulin action. This condition is prevalent worldwide and is associated with morbidity and mortality secondary to complications such as myocardial infarction, stroke and end-stage renal disease. The importance of tight control of blood glucose in either preventing or delaying the progression of complications is recognized. Currently, there are many therapeutic options to treat hyperglycemia in type 2 diabetes. However, tight control is difficult to achieve and is often associated with side-effects. Recent advances in understanding insulin secretion, action and signaling have led to the development of new pharmacological agents. In this article, we review new molecules that are promising candidates for the future management of diabetes, focusing on their mechanism of action, efficacy, safety profile and potential benefits compared with pharmacological agents that are available currently.

Correlates of diabetes-related distress in type 2 diabetes: Findings from the benchmarking network for clinical and humanistic outcomes in diabetes (BENCH-D) study.

OBJECTIVE: To evaluate correlates of high diabetes-related distress (HD) among individuals with type 2 diabetes mellitus (T2DM). METHODS: The study involved a sample of patients with T2DM who filled in the Problem Areas in Diabetes questionnaire (PAID-5); a score ≥ 40 indicates HD. Additional instruments included: SF12 health survey (SF12), Well-Being Index (WHO-5), Diabetes Empowerment Scale-Short Form (DES-SF), Patient Assessment of Chronic Illness Care-Short Form (PACIC-SF), Health Care Climate-Short Form (HCC-SF), Global Satisfaction with Diabetes Treatment (GSDT), Summary of Diabetes Self-Care Activities (SDSCA-6); Barriers to Medications (BM), Perceived Social Support (PSS). Clinical data were extracted from computerized medical records. Multivariable logistic regression analyses were performed to identify correlates of HD. RESULTS: Of 2374 patients (mean age 65.0±10.2 years, diabetes duration 14.0±15.3 years, 59.9% males), 1429 (60.2%) had HD. Compared to patients with a PAID-5 score<40 those with HD were more often female, living alone, had a lower level of education, higher HbA1c levels, a greater perceived impact of hyperglycemic and hypoglycemic symptoms, a greater number of diabetes-related complications, lower scores of WHO-5, DES-SF, PSS, GSDT, SF-12 PCS, SDSCA-healthy diet and physical activity subscales, higher scores of BM and SDSCA-SMBG component. Multivariable analyses confirmed the relationship between HD and symptoms of hyperglycemia, levels of empowerment, global satisfaction with treatment, perception of barriers to medication, and psychological well-being. Conclusion HD is extremely common among people with T2DM, affecting almost two-thirds of patients. High levels of distress are associated with worse clinical and psychosocial outcomes and should be considered as a key patient-centered indicator.

Interplay among patient empowerment and clinical and person-centered outcomes in type 2 diabetes. The BENCH-D study.

OBJECTIVE: We evaluated empowerment in T2DM and identified its correlates. METHODS: A sample of individuals self-administered the Diabetes Empowerment Scale-Short Form (DES-SF) and other 9 validated instruments (person-centered outcomes). Correlates of DES-SF were identified through univariate and multivariate analyses. For person-centered outcomes, ORs express the likelihood of being in upper quartile of DES-SF (Q4) by 5 units of the scale. RESULTS: Overall, 2390 individuals were involved. Individuals in Q4 were younger, more often males, had higher levels of school education, lower HbA1c levels and prevalence of complications as compared to individuals in the other quartiles. The likelihood of being in Q4 was directly associated with higher selfreported self-monitoring of blood glucose (SDSCA6-SMBG) (OR=1.09; 95% CI: 1.03-1.15), higher satisfaction with diabetes treatment (GSDT) (OR=1.15; 95% CI: 1.07-1.25), perceived quality of chronic illness care and patient support (PACIC-SF) (OR=1.23; 95% CI: 1.16-1.31), and better person-centered communication (HCC-SF) (OR=1.10; 95% CI: 1.01-1.19) and inversely associated with diabetes-related distress (PAID-5) (OR=0.95; 95% CI: 0.92-0.98). Adjusted DES-SF mean scores ranged between centers from 69.8 to 93.6 (intra-class correlation=0.10; p<0.0001). CONCLUSIONS: Empowerment was associated with better glycemic control, psychosocial functioning and perceived access to person-centered chronic illness care. Practice of diabetes center plays a specific role. PRACTICE IMPLICATIONS: DES-SF represents a process and outcome indicator in the practice of diabetes centers.

Glucagon-like peptide-1 promotes islet cell growth and inhibits apoptosis in Zucker diabetic rats.

A constant remodeling of islet cell mass mediated by proliferative and apoptotic stimuli ensures a dynamic response to a changing demand for insulin. In this study, we investigated the effect of glucagon-like peptide-1 (GLP-1) in Zucker diabetic rats, an animal model in which the onset of diabetes occurs when the proliferative potential and the rate of beta-cell apoptosis no longer compensate for the increased demand for insulin. We subjected diabetic rats to a 2-d infusion of GLP-1 and tested their response to an ip glucose tolerance test. GLP-1 produced a significant increase of insulin secretion, which was paralleled by a decrease in plasma glucose levels (P < 0.001 and P < 0.01, respectively). Four days after the removal of the infusion pumps, rats were killed and the pancreas harvested to study the mechanism by which GLP-1 ameliorated glucose tolerance. Ex vivo immunostaining with the marker of cell proliferation, Ki-67, showed that the metabolic changes observed in rats treated with GLP-1 were associated with an increase in cell proliferation of the endocrine and exocrine component of the pancreas. Terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end-labeling staining, a marker of cellular apoptosis, indicated a reduction of apoptotic cells within the islet as well in the exocrine pancreas in GLP-1-treated rats. Double immunostaining for the apoptotic marker caspase-3 and for insulin showed a significant reduction of caspase-3 expression and an increase in insulin content in GLP-1-treated animals. Finally, staining of pancreatic sections with the nuclear dye 4,6-Diaminidino-2-phenyl-dihydrochloride demonstrated a marked reduction of fragmented nuclei in the islet cells of rats treated with GLP-1. Our findings provide evidence that the beneficial effects of GLP-1 in Zucker diabetic rats is mediated by an increase in islet cell proliferation and a decrease of cellular apoptosis.

Glucagon-like peptide 1 inhibits cell apoptosis and improves glucose responsiveness of freshly isolated human islets.

The peptide hormone, glucagon-like peptide 1 (GLP-1), has been shown to increase glucose-dependent insulin secretion, enhance insulin gene transcription, expand islet cell mass, and inhibit beta-cell apoptosis in animal models of diabetes. The aim of the present study was to evaluate whether GLP-1 could improve function and inhibit apoptosis in freshly isolated human islets. Human islets were cultured for 5 d in the presence, or absence, of GLP-1 (10 nm, added every 12 h) and studied for viability and expression of proapoptotic (caspase-3) and antiapoptotic factors (bcl-2) as well as glucose-dependent insulin production. We observed better-preserved three-dimensional islet morphology in the GLP-1-treated islets, compared with controls. Nuclear condensation, a feature of cell apoptosis, was inhibited by GLP-1. The reduction in the number of apoptotic cells in GLP-1-treated islets was particularly evident at d 3 (6.1% apoptotic nuclei in treated cultures vs. 15.5% in controls; P < 0.01) and at d 5 (8.9 vs. 18.9%; P < 0.01). The antiapoptotic effect of GLP-1 was associated with the down-regulation of active caspase-3 (P < 0.001) and the up-regulation of bcl-2 (P < 0.01). The effect of GLP-1 on the intracellular levels of bcl-2 and caspase-3 was observed at the mRNA and protein levels. Intracellular insulin content was markedly enhanced in islets cultured with GLP-1 vs. control (P < 0.001, at d 5), and there was a parallel GLP-1-dependent potentiation of glucose-dependent insulin secretion (P < 0.01 at d 3; P < 0.05 at d 5). Our findings provide evidence that GLP-1 added to freshly isolated human islets preserves morphology and function and inhibits cell apoptosis.

Gene expression profiling of cultured human islet preparations.

The expression of functional and regulatory genes by islet cells is a key determinant for the success of islet transplantation. The aim of this study is twofold: first, to characterize the cluster of genes expressed in human islet isolations; and second, to validate the capability of gene array technology to assess with accuracy the expression of various transcripts. RNA from isolated islet preparations obtained from three independent donors was converted to cDNA and then transcribed to cRNA. Individual cRNA preparations were then hybridized to U133A microarrays carrying approximately 23,000 genes, and analyzed using GeneSpring (SiliconGenetics, Redwood City, CA) software. Real-time reverse transcription-polymerase chain reaction was performed to validate results obtained by microarray analysis. Microarray analysis identified the expression of about 7,000 genes transcribed in cultured human islet preparations. Enzymes represented the most abundant class of genes identified, followed by nuclear binding proteins, signal transduction molecules, transport proteins, and growth factor receptors and their ligands. Real-time polymerase chain reaction confirmed the identification of various islet-specific genes detected by microarray analysis, but also showed that such genes as pancreatic duodenal homeobox 1 protein and glucagon-like peptide 1 receptor, which were not detected by gene array, can be readily identified and quantified. In addition, gene array produced a suboptimal quantification of genes expressed in large amounts by islet cells. Indeed, the abundance of mRNA for insulin when compared with the level of somatostatin mRNA was not as different as one would have predicated based on the classic knowledge of islet physiology. Gene array analysis appears to be a valuable tool to obtain preliminary information of genes expressed by a given tissue. The expression levels of transcripts expressed in very low or very high quantities need to be confirmed by an independent technique.

The role of GLP-1 in the regulation of islet cell mass.

Glucagon-like peptide-1 (GLP-1) is an incretin hormone capable of restoring euglycemia in glucose-intolerant subjects and improving glucose control in individuals with type 2 diabetes. Whether the antidiabetic properties of GLP-1 are exclusively the result of its acute postprandial action is being investigated. A GLP-1-dependent differentiation of pancreatic precursor cells into mature beta-cells has been proposed. In addition, GLP-1 has been shown to have antiapoptotic activity in cultured insulin-secreting cells and in an animal model in which diabetes occurs as a consequence of an excessive rate of beta-cell apoptosis. Studies from our laboratory, and others, lead us to propose that GLP-1 is a growth factor for pancreatic cells and it is a regulator of islet cell mass. The aim of this article is to review those reports that have emphasized the role of GLP-1 as a regulator of islet cell mass as well as its insulin secretory action.

GLP-1 receptor agonists are growth and differentiation factors for pancreatic islet beta cells.

Glucagon-like peptide-1 (GLP-1) is an incretin hormone that, when given exogenously, is capable of normalizing blood glucose in individuals with type 2 diabetes. Until recently most of the research on this compound had been related to its insulinotropic properties. However, GLP-1 also regulates insulin synthesis and proinsulin gene expression, as well as the components of the glucose-sensing machinery. In addition to regulating insulin release, it is involved in regulating the secretion of at least two other islet hormones--glucagon and somatostatin. Extraislet effects of GLP-1 include a role in the central nervous system stress response, hypothalamic-pituitary function, and the suppression of gastric emptying. Recent studies from our own and other laboratories show that GLP-1 can regulate islet growth and is a differentiation factor of the endocrine pancreas. This leads us to propose that GLP-1 and GLP-1 receptor agonists, in the context of long-term treatment of type 2 diabetes, will have broader biological action on the endocrine pancreas than was earlier anticipated. We propose that GLP-1 is a growth factor for pancreatic endocrine cells and can increase islet cell mass. Here we review those reports that have highlighted its role as a factor for islet cell growth and differentiation.

GLP-1 stimulates glucose-derived de novo fatty acid synthesis and chain elongation during cell differentiation and insulin release.

Glucagon-like peptide-1 (GLP-1, 7-36) is capable of restoring normal glucose tolerance in aging, glucose-intolerant Wistar rats and is a potent causal factor in differentiation of human islet duodenal homeobox-1-expressing cells into insulin-releasing beta cells. Here we report stable isotope-based dynamic metabolic profiles of rat pancreatic epithelial (ARIP) and human ductal tumor (PANC-1) cells responding to 10 nM GLP-1 treatment in 48 h cultures. Macromolecule synthesis patterns and substrate flow measurements using gas chromatography/mass spectrometry (MS) and the stable [1,2-13C2]glucose isotope as the tracer showed that GLP-1 induced a significant 20% and 60% increase in de novo fatty acid palmitate synthesis in ARIP and PANC-1 cells, respectively, and it also induced a significant increase in palmitate chain elongation into stearate utilizing glucose as the primary substrate. Distribution of 13C in other metabolites indicated no changes in the rates of nucleic acid ribose synthesis, glutamate oxidation, or lactate production. Tandem high-performance liquid chromatography-ion trap MS analysis of the culture media demonstrated mass insulin secretion by GLP-1-treated tumor cells. Metabolic profile changes in response to GLP-1-induced cell differentiation include selective increases in de novo fatty acid synthesis from glucose and consequent chain elongation, allowing increased membrane formation and greater insulin availability and release.

Expression of activated Notch3 in transgenic mice enhances generation of T regulatory cells and protects against experimental autoimmune diabetes.

Thymic-derived dysregulated tolerance has been suggested to occur in type 1 diabetes via impaired generation of CD4(+)CD25(+) T regulatory cells, leading to autoimmune beta cell destruction. In this study, we demonstrate that Notch3 expression is a characteristic feature of CD4(+)CD25(+) cells. Furthermore, streptozotocin-induced autoimmune diabetes fails to develop in transgenic mice carrying the constitutively active intracellular domain of Notch3 in thymocytes and T cells. The failure to develop the disease is associated with an increase of CD4(+)CD25(+) T regulatory cells, accumulating in lymphoid organs, in pancreas infiltrates and paralleled by increased expression of IL-4 and IL-10. Accordingly, CD4(+) T cells from Notch3-transgenic mice inhibit the development of hyperglycemia and insulitis when injected into streptozotocin-treated wild-type mice and display in vitro suppressive activity. These observations, therefore, suggest that Notch3-mediated events regulate the expansion and function of T regulatory cells, leading to protection from experimental autoimmune diabetes and identify the Notch pathway as a potential target for therapeutic intervention in type 1 diabetes.