Clinical outcomes and medication adherence in acute coronary syndrome patients with and without type 2 diabetes mellitus: a longitudinal analysis 2006-2011.

BACKGROUND: The presence of type 2 diabetes mellitus magnifies the risks associated with acute coronary syndrome (ACS), increasing the risk of recurrent cardiovascular events (CVEs) and doubling the risk of death. Managing cardiovascular risk factors has little effect on lowering the mortality risk in patients with type 2 diabetes. OBJECTIVE: To evaluate the relationship between type 2 diabetes mellitus and subsequent CVEs and medication adherence following ACS hospitalization. METHODS: Patients with ACS were identified using ICD-9-CM codes for acute myocardial infarction or unstable angina. The risk of subsequent CVEs was assessed at 1 and 3 years after the index ACS event based on type 2 diabetes status, adjusting for baseline demographic characteristics, comorbidities, medication use, and index ACS characteristics. RESULTS: Of 140,903 patients with ACS (mean age 66.8 years, 58.6% male), 27.4% had type 2 diabetes. During follow-up, 22.0% had subsequent CVEs (26.2% type 2 diabetes, 19.0% nondiabetes). After adjusting for other covariates, type 2 diabetes was associated with increased risk of subsequent CVEs by 9.7% at 1 year and 10.2% at 3 years (both P < 0.001). Most patients were not revascularized at first recurrence after index ACS discharge (79.2% type 2 diabetes, 77.5% nondiabetes). Patients with type 2 diabetes had statistically significant higher adherence rates for antiplatelet agents at 1 year and antihypertensives at 1 and 3 years versus nondiabetes patients. Persistence was higher in the type 2 diabetes group for antihypertensives and in the nondiabetes group for antiplatelet agents and statins. CONCLUSIONS: This analysis demonstrates that patients with type 2 diabetes have a higher risk of subsequent CVEs following an initial event versus those without diabetes, despite evidence of higher treatment persistence for certain medications. Adherence rates remained suboptimal, suggesting a continuing need for patient education.

Effects of exenatide and lifestyle modification on body weight and glucose tolerance in obese subjects with and without pre-diabetes.

OBJECTIVE: To assess the effects of exenatide on body weight and glucose tolerance in nondiabetic obese subjects with normal or impaired glucose tolerance (IGT) or impaired fasting glucose (IFG). RESEARCH DESIGN AND METHODS: Obese subjects (n = 152; age 46 +/- 12 years, female 82%, weight 108.6 +/- 23.0 kg, BMI 39.6 +/- 7.0 kg/m(2), IGT or IFG 25%) were randomized to receive exenatide (n = 73) or placebo (n = 79), along with lifestyle intervention, for 24 weeks. RESULTS Exenatide-treated subjects lost 5.1 +/- 0.5 kg from baseline versus 1.6 +/- 0.5 kg with placebo (exenatide--placebo, P < 0.001). Placebo-subtracted difference in percent weight reduction was -3.3 +/- 0.5% (P < 0.001). Both groups reduced their daily calorie intake (exenatide, -449 cal; placebo, -387 cal). IGT or IFG normalized at end point in 77 and 56% of exenatide and placebo subjects, respectively. CONCLUSIONS: Exenatide plus lifestyle modification decreased caloric intake and resulted in weight loss in nondiabetic obesity with improved glucose tolerance in subjects with IGT and IFG.

Variable RXR requirements for thyroid hormone responsiveness of endogenous genes.

Thyroid hormone receptors heterodimerize with retinoid X receptors in vitro and it is widely assumed that these heterodimers mediate the T3 induction of target genes. However, the importance of RXR for the T3 induction of endogenous genes has not been assessed. We used cDNA microarrays to identify 54 genes induced by T3 in Neuro2a cells that express thyroid hormone receptor beta. RNA interference-mediated knock down of endogenous RXRs showed that these genes vary from being highly dependent on RXR for T3 induction to being independent of RXR. Thus, the availability of RXR may differentially regulate the T3 induction of subsets of genes within a cell. Furthermore, coregulatory proteins that preferentially interact with TR homodimers or RXR-TR heterodimers may further expand the range of T3 response for genes within the same cell.

Delineation, functional validation, and bioinformatic evaluation of gene expression in thyroid follicular carcinomas with the PAX8-PPARG translocation.

A subset of follicular thyroid carcinomas contains a balanced translocation, t(2;3)(q13;p25), that results in fusion of the paired box gene 8 (PAX8) and peroxisome proliferator-activated receptor gamma (PPARG) genes with concomitant expression of a PAX8-PPARgamma fusion protein, PPFP. PPFP is thought to contribute to neoplasia through a mechanism in which it acts as a dominant-negative inhibitor of wild-type PPARgamma. To better understand this type of follicular carcinoma, we generated global gene expression profiles using DNA microarrays of a cohort of follicular carcinomas along with other common thyroid tumors and used the data to derive a gene expression profile characteristic of PPFP-positive tumors. Transient transfection assays using promoters of four genes whose expression was highly associated with the translocation showed that each can be activated by PPFP. PPFP had unique transcriptional activities when compared with PAX8 or PPARgamma, although it had the potential to function in ways qualitatively similar to PAX8 or PPARgamma depending on the promoter and cellular environment. Bioinformatics analyses revealed that genes with increased expression in PPFP-positive follicular carcinomas include known PPAR target genes; genes involved in fatty acid, amino acid, and carbohydrate metabolism; micro-RNA target genes; and genes on chromosome 3p. These results have implications for the neoplastic mechanism of these follicular carcinomas.

PAX8-peroxisome proliferator-activated receptor gamma (PPARgamma) disrupts normal PAX8 or PPARgamma transcriptional function and stimulates follicular thyroid cell growth.

Follicular thyroid carcinomas are associated with a chromosomal translocation that fuses the thyroid-specific transcription factor paired box gene 8 (PAX8) with the nuclear receptor peroxisome proliferator-activated receptor gamma (PPARgamma). This study investigated the transcriptional mechanisms by which PAX8-PPARgamma regulates follicular thyroid cells. In HeLa cells, rat follicular thyroid (FRTL-5) cells, or immortalized human thyroid cells, PAX8-PPARgamma stimulated transcription from PAX8-responsive thyroperoxidase and sodium-iodide symporter promoters in a manner at least comparable with wild-type PAX8. In contrast, PAX8-PPARgamma failed to stimulate transcription from the thyroglobulin promoter and blocked the synergistic stimulation of this promoter by wild-type PAX8 and thyroid transcription factor-1. Unexpectedly, PAX8-PPARgamma transcriptional function on a PPARgamma-responsive promoter was cell-type dependent; in HeLa cells, PAX8-PPARgamma dominantly inhibited expression of the PPARgamma-responsive promoter, whereas in FRTL-5 and immortalized human thyroid cells PAX8-PPARgamma stimulated this promoter. In gel shift analyses, PAX8-PPARgamma bound a PPARgamma-response element suggesting that its transcriptional function is mediated via direct DNA contact. A biological model of PAX8-PPARgamma function in follicular thyroid cells was generated via constitutive expression of the fusion protein in FRTL-5 cells. In this model, PAX8-PPARgamma expression was associated with enhanced growth as assessed by soft agar assays and thymidine uptake. Therefore, PAX8-PPARgamma disrupts normal transcriptional regulation by stimulating some genes and inhibiting others, the net effect of which may mediate follicular thyroid cell growth and loss of differentiation that ultimately leads to carcinogenesis.