Changes in the Prescription of Glucose-Lowering Medications in Patients With Type 2 Diabetes Mellitus After a Cardiovascular Event: A Call to Action From the DATAFILE Study.

Background Evidence accumulated that some glucose-lowering medications protect against cardiovascular events ( CVEs ) in patients with type 2 diabetes mellitus (T2DM) and established cardiovascular disease. The present study evaluated if and how glucose-lowering medication prescription pattern changes in T2DM after a CVE. Methods and Results DATAFILE (Diabetes Therapy After a Cardiovascular Event) was a retrospective multicenter study conducted at 12 diabetes mellitus specialist outpatient clinics in Italy. We identified T2DM patients with an incident CVE for whom a follow-up visit was available after the event. We selected control T2DM patients without an incident CVE , who were matched with cases for age, sex, known diabetes mellitus duration, baseline hemoglobin A1c, kidney function, and follow-up time. We extracted clinical variables and compared prescribed therapies at baseline and follow-up. We included 563 patients with and 497 matched patients without an incident CVE . As expected, patients with a subsequent CVE had a higher baseline prevalence of ischemic heart disease. After a median of 9.5 months, in patients with versus those without a CVE , there was a significant increase in the prescription of beta-blockers, loop diuretics, dual antiplatelet therapy, and, among glucose-lowering medications, a significant decrease in metformin. Hemoglobin A1c marginally declined only in the control group, whereas low-density lipoprotein cholesterol decreased only in patients with CVE . Conclusions This study highlights that occurrence of a CVE in T2DM patients did not prime the prescription of glucose-lowering medications provided with cardiovascular protective effects, even though glucose control remained poor. These data emphasize the need to optimize the therapeutic regimen of T2DM patients with established cardiovascular disease, according to updated guidelines.

A polymorphism at the IL6ST (gp130) locus is associated with traits of the metabolic syndrome.

The interleukin 6 signal transducer (IL6ST, also known as gp130) is a ubiquitously expressed intermediate of the interleukin-6 signaling pathway. We investigated whether genetic variability at the IL6ST locus is involved in the modulation of metabolic traits and the etiology of the metabolic syndrome (MS). Four haplotype-tagging single nucleotide polymorphisms were typed in two populations of non-diabetic subjects, one from Northern Italy (Padua (PD), n = 630), the other from Southern Italy (San Giovanni Rotondo (SGR), n = 553). In the PD population, a nominally significant association was observed between fasting glucose and rs715180 (P = 0.02), rs3729960 (P = 0.02), and rs10940495 (P = 0.05), between homeostasis model assessment index (HOMA(IR)) and rs715180 (P = 0.04), and between triglycerides and rs3729960 (P = 0.03). In the SGR population, high-density lipoprotein (HDL) levels were associated with rs715180 (P = 0.01), systolic blood pressure and waist circumference with rs3729960 (P = 0.005 and 0.02, respectively). The frequency of rs715180 minor allele carriers progressively decreased from individuals with no MS components to those with three or more components (P for trend = 0.006 in the two populations combined). Compared to major allele homozygotes, minor allele carriers had 40% lower odds of having at least one MS component (Odds ratio = 0.6, 95% confidence interval 0.4-0.8, P = 0.005). These findings point to IL6ST variants as possible determinants of impaired glucose metabolism and other abnormalities of MS.

Genetic variability at the leptin receptor (LEPR) locus is a determinant of plasma fibrinogen and C-reactive protein levels.

OBJECTIVE: Cellular and animal studies suggest that leptin has proinflammatory and prothrombotic effects that could link increased adipose mass directly to atherogenesis. To investigate this hypothesis, we examined the effect of genetic variability at the leptin receptor (LEPR) locus on the plasma levels of fibrinogen and CRP--two markers of inflammation and susceptibility to atherosclerosis. METHODS AND RESULTS: Linkage disequilibrium analysis of 71 single-nucleotide polymorphisms (SNPs) spanning the LEPR locus revealed four haplotype blocks that could be tagged by 11 SNPs. In 630 healthy Caucasian individuals, variability in block #4 was significantly associated with plasma fibrinogen (p=0.005), accounting for 3% of its variance (r2=0.030). The same block was also associated with CRP levels (p=0.049, r2=0.022). The effect was strongest for two of the SNPs in this block. At rs3790432, fibrinogen was 10% higher in minor allele homozygotes than in major allele homozygotes and intermediate in heterozygotes (p=0.015). At rs1805096, it was 5% higher (p=0.007) and CRP 32% higher (p=0.011) in major allele homozygotes than in minor allele carriers. This pattern of association was also evident in the haplotype analysis. CONCLUSIONS: Association of leptin receptor variability with inflammatory traits supports the hypothesis that leptin may play a role in atherogenesis.

A visfatin promoter polymorphism is associated with low-grade inflammation and type 2 diabetes.

Visfatin (also known as pre-B cell colony-enhancing factor, or PBEF) is a pro-inflammatory adipokine expressed predominantly in visceral fat. We investigated whether polymorphisms at the visfatin/PBEF locus influence the risk of type 2 diabetes (T2D). Linkage disequilibrium analysis of 52 single nucleotide polymorphisms spanning the entire gene (34.7 kb) plus 20.5 kb of the upstream region and 25.5 kb of the downstream region revealed a single haplotype block that could be tagged by seven single nucleotide polymorphisms. These seven tags were typed in a group of T2D patients (n = 814) and a group of non-diabetic controls (n = 320) of white origin. A significant association was observed at -948C>A, with minor allele frequencies of 0.157 in T2D cases and 0.119 in non-diabetic controls (p = 0.021). In a non-diabetic population (n = 630), the same -948 allele that conferred increased risk of T2D was significantly associated with higher plasma levels of fibrinogen and C-reactive protein (p = 0.0022 and 0.0038, respectively). However, no significant associations were observed with BMI, waist circumference, serum glucose levels, or fasting insulin levels. Our findings suggest that the visfatin/PBEF gene may play a role in determining T2D susceptibility, possibly by modulating chronic, low-grade inflammatory responses.

A common haplotype at the CD36 locus is associated with high free fatty acid levels and increased cardiovascular risk in Caucasians.

CD36 is a class B scavenger receptor recognizing a variety of ligands including long-chain fatty acids and modified LDL. We investigated whether genetic variability at this locus is a determinant of free fatty acid (FFA) plasma levels and risk of coronary artery disease (CAD) in Caucasians. Typing of 21 polymorphic markers, evenly spanning the CD36 gene, revealed two linkage disequilibrium (LD) blocks that could be tagged by five polymorphisms (-33137A>G, -31118G>A, 25444G>A, 27645del>ins and 30294G>C). In 585 non-diabetic individuals of Caucasian origin, the 30294G>C polymorphism was significantly associated with FFA levels (P = 0.02)--an effect that was especially visible among men (P = 0.009). A similar association was observed in this gender at -33137 (P = 0.008) and -31118 (P = 0.028). When the five tag polymorphisms were considered together, men carrying the AGGIG haplotype had 31% higher FFA (P = 0.0002) and 20% higher triglycerides (P = 0.025) than non-carriers. The same haplotype was associated with increased risk of CAD in 197 type 2 diabetic individuals from the US (OR = 2.3, 95% CI 1.2-4.2). A similar tendency was observed in a group of 321 type 2 diabetic individuals from Italy (OR = 1.4, 0.9-2.3), resulting in an overall relative risk of 1.6 (1.1-2.3, P = 0.015) in the two populations considered together. By targeted resequencing, we identified a common variant in the CD36 promoter that is in strong LD with the AGGIG haplotype and could be partly responsible for these findings. In conclusion, this comprehensive study of CD36 variability indicates that the common polymorphisms at this locus modulate lipid metabolism and cardiovascular risk in Caucasians.

Effects of galanin on proliferation and apoptosis of immature rat thymocytes.

Evidence indicates that some regulatory peptides (endothelins, cholecystokinin and VIP) are involved in the control of thymus growth, and we have investigated whether galanin may be included in this group of peptides. In fact, galanin, a 29-amino acid peptide acting through three subtypes of G protein-coupled receptors (GalR1, GalR2 and GalR3), seems to play a role in the control of the immune system. Reverse transcription (RT)-polymerase chain reaction (PCR) allowed the detection of galanin, GalR1 and GalR3 mRNAs in the thymus cortex of immature (20-day-old) rats, while GalR2 expression was very weak or absent. Immature rats were given three subcutaneous injections (28, 16 and 4 h before sacrifice) of 2 nmol/100 g galanin and or the galanin-receptor antagonist (galanin-A) [D-Thr(6),D-Trp(8,9),15-ol]-galanin(1-15), and 0.1 mg/100 g vincristine 3 h before sacrifice. Thymuses were processed for light microscopy and the percentage of metaphase-arrested cells (mitotic index) was evaluated. Galanin-A increased the thymus mitotic index, while galanin was ineffective, thereby suggesting that endogenous galanin exerts a maximal tonic inhibitory effect on the proliferative activity of thymocytes in immature rats. Immature rat thymocytes were cultured in vitro for 12 h in the presence of 10(-6) M galanin and/or galanin-A. Hoechst 33342 and propidium iodide were added to the cultures, and the percentage of apoptotic and necrotic cells was determined under fluorescence microscope. Galanin increased apoptotic index, and the effect was prevented by galanin-A. Neither galanin nor galanin-A altered necrotic index. Collectively, our findings indicate that galanin, probably acting through GalR1 and GalR3, exerts antiproliferative and proapoptotic effects on immature rat thymocytes, which makes it likely that this peptide plays a role in the autocrine/paracrine functional regulation of immune system in the rat.

11beta-Hydroxysteroid dehydrogenase types 1 and 2 are up- and downregulated in cortisol-secreting adrenal adenomas.

BACKGROUND: 11beta-Hydroxysteroid dehydrogenase types 1 and 2 (11betaHSD1 and 11betaHSD2) are two isoenzymes that convert inactive glucocorticoids (e.g., cortisone) to their active forms (e.g., cortisol) and vice versa. Abundant evidence indicates that 11betaHSD2 is expressed as mRNA and protein in both adrenal cortex and adrenal tumors. In contrast, 11betaHSD1 has been investigated to a much lesser degree. We therefore studied and compared the expression and activity of the two isoenzymes in the human adrenal cortex (HAC) and cortisol-secreting adenomas (CSAs). METHODS: Six HAC and six CSA specimens were studied. 11betaHSD1 and 11betaHSD2 gene expression was studied by conventional and semiquantitative reverse transcription-polymerase chain reaction. 11betaHSD1 and 11betaHSD2 activity was assayed by measuring the capacity of both microsomal fraction and tissue fragments to convert [3H]cortisone to [3H]cortisol and vice versa. Steroid hormones were separated and purified by high-performance liquid chromatography, and cortisol concentration was measured by radioimmunoassay. RESULTS: Semiquantitative reverse transcription-polymerase chain reaction and enzymatic assay demonstrated higher 11betaHSD1 expression and activity and lower 11betaHSD2 expression and activity in CSAs than in HACs. CSA slices secreted larger amounts of cortisol than did HAC specimens, and the cholesterol side-chain-cleaving enzyme inhibitor aminoglutethimide, by blocking the early step of steroid synthesis, reduced cortisol secretion by approximately 70%. Aminoglutethimide decreased [3H]cortisol production from [3H]cortisone and increased [3H]cortisone production from [3H]cortisol in both tissues, thereby annulling differences in 11betaHSD1 and 11betaHSD2 activity between HACs and CSAs. CONCLUSION: Collectively, our findings indicate that 1) both 11betaHSD isoenzymes are expressed as mRNA and proteins in the HAC and CSA, with 11betaHSD1 upregulated and 1betaHSD2 downregulated in CSAs; and 2) 11betaHSD1 and 11betaHSD2 activity is positively and negatively correlated with the intracellular concentration of steroid hormones. Hence, 11betaHSD isoenzymes could act as amplifiers of the secretagogue effect of agonists and could contribute to the elevated hormonal secretion of CSAs.

Glucose tolerance during moderate alcohol intake: insights on insulin action from glucose/lactate dynamics.

Moderate alcohol (ETOH) intake has been associated with a significant reduction in risk for infarction among general populations. In this study, we assessed the effects of low-dose ETOH (40 g over 3-h period as vodka) on the interaction between glucose (G), insulin, and lactate (L) during the insulin-modified frequently sampled i.v. glucose tolerance test (FSIGT) (0.3 U/kg body weight between 20-25 min) in eight normal volunteers. In the control (C) study, water was administered. An insulin-independent two-compartment model was used to describe G and L kinetics. Insulin sensitivity (S(I)) was significantly higher in the ETOH study than in the C study (2.49 +/- 0.52 vs. 0.92 +/- 0.20 10(-4) min(-1)microU(-1)ml, C vs. ETOH; P = 0.0391). No significant differences were observed in G effectiveness (0.029 +/- 0.004 vs. 0.033 +/- 0.004 min(-1)). Blood L levels were higher during FSIGT when ETOH was administered [area under the curve (AUC), 201 plus minus 16 vs. 123 +/- 23 mmol/liter in 240 min; P = 0.0001]. The dynamic analysis of blood L concentrations showed that ETOH also significantly decreased L clearance (0.0016 +/- 0.0011 vs. 0.0029 +/- 0.0002 min(-1); P = 0.0156), whereas no difference was observed for the fractional conversion of the rate of G disappearance to L (0.0033 +/- 0.0012 vs. 0.0031 +/- 0.0005 min(-1)). ETOH decreased baseline plasma FFA concentration; AUC of FFA was markedly reduced with ETOH (65 +/- 14 vs. 109 plus minus 17 mmol/liter in 240 min; P = 0.0063) and inversely correlated with S(I) (r = 0.693; P = 0.0029). The amount of C-peptide in 240 min as well as the amounts before and after insulin administration were not different between the two tests. We concluded that G and L kinetics derived from FSIGT shows that moderate ETOH intake: 1) improves insulin action; 2) decreases L clearance; and 3) does not affect beta cell function. Because ETOH at moderate doses has a marked antilipolytic action, it might improve insulin action by improving substrate competition. The present findings suggest that moderate alcohol consumption in the diet should not be discouraged.

Pituitary adenylate cyclase-activating polypeptide and PACAP receptor expression and function in the rat adrenal gland.

Pituitary adenylate cyclase-activating polypeptide (PACAP) is a basic 38-amino acid peptide, which acts through three main G protein-coupled VIP/PACAP receptor subtypes, called PAC1, VPAC1 and VPAC2. We have investigated the expression and function of PACAP and its receptors in the rat adrenal gland. Reverse transcription (RT)-polymerase chain reaction (PCR) and radioimmune assay (RIA) allowed the detection of PACAP expression as mRNA and protein exclusively in adrenal medulla (AM). RT-PCR and quantitative autoradiography, using [(125)I]PACAP and selective VIP/PACAP receptor ligands, demonstrated the expression of PAC1 only in AM, and VPAC1 and VPAC2 in both AM and zona glomerulosa (ZG), PACAP receptor expression being absent in zona fasciculata/reticularis (ZF/R). PACAP38 concentration-dependently increased aldosterone secretion from dispersed ZG cells and catecholamine secretion from AM tissue, the maximal effective concentration being 10(-7) M. ZF/R cells did not display any secretory response to PACAP38. Aldosterone response of ZG cells to 10(-7) M PACAP38 was unaffected by the PAC1-antagonist (A) PACAP(6-38), and significantly decreased by the VPAC1-A [Ac-His(1),D-Phe(2),Lys(15),Arg(16)]VIP(3-7) GRF(8-27)-NH(2). Catecholamine response of AM tissue to PACAP38 was reduced, but not abolished, by both PAC1-A and VPAC1-A. The VPAC2 agonist (ago) Ro25-1553 elicited sizeable secretory responses from both ZG cells and AM tissue. PACAP38 (10(-7) M) evoked a marked rise in cyclic-AMP (cAMP) and inositol-1,4,5-triphosphate (IP3) production by ZG cells and AM tissue. cAMP response of ZG cells was lowered by VPAC1-A, and that of AM tissue by both PAC1-A and VPAC1-A. IP3 response of ZG cells and AM tissue was unaffected by PAC1-A and decreased by VPAC1-A. VPAC2-ago did not affect cAMP release, but raised IP3 production by both ZG cells and AM tissue. Aldosterone response of ZG cells and catecholamine response of AM tissue to PACAP38 (10(-7) M) were reduced by the adenylate cyclase (AC) and phospholipase-C (PLC) inhibitors (I) SQ-22536 and U-73122, as well as by the protein kinase (PK)A-I H-89 and PKC-I calphostin-C. Conversely, the secretory responses of both ZG and AM preparations to VPAC2-ago were annulled by PLC-I, lowered by PKC-I, and unaffected by either AC-I or PKA-I. Collectively, our findings allow us to conclude that in the rat adrenals: i) PACAP biosynthesis exclusively occurs in the AM; ii) ZG cells are provided with functional VPAC1 and VPAC2 receptors, whose activation by PACAP evokes a moderate aldosterone response; iii) AM cells possess all the subtypes of VIP/PACAP receptors, whose activation by PACAP elicits a marked catecholamine response; and iv) PAC1 receptors are coupled to the AC-dependent cascade, VPAC1 receptors to both the AC- and PLC-dependent cascades, and VPAC2 receptors exclusively to the PLC-dependent cascade.