Pioglitazone as Add-on THERAPY in Patients with Type 2 Diabetes Mellitus Inadequately Controlled with Dapagliflozin and Metformin: Double-Blind, Randomized, Placebo-Controlled Trial.

Background: This study assessed the efficacy and safety of triple therapy with pioglitazone 15 mg add-on versus placebo in patients with type 2 diabetes mellitus (T2DM) inadequately controlled with metformin and dapagliflozin. Methods: In this multicenter, double-blind, randomized, phase 3 study, patients with T2DM with an inadequate response to treatment with metformin (≥1,000 mg/day) plus dapagliflozin (10 mg/day) were randomized to receive additional pioglitazone 15 mg/day (n=125) or placebo (n=125) for 24 weeks. The primary endpoint was the change in glycosylated hemoglobin (HbA1c) levels from baseline to week 24 (ClinicalTrials.gov identifier: NCT05101135). Results: At week 24, the adjusted mean change from baseline in HbA1c level compared with placebo was significantly greater with pioglitazone treatment (-0.47%; 95% confidence interval, -0.61 to -0.33; P<0.0001). A greater proportion of patients achieved HbA1c <7% or <6.5% at week 24 with pioglitazone compared to placebo as add-on to 10 mg dapagliflozin and metformin (56.8% vs. 28% for HbA1c <7%, and 23.2% vs. 9.6% for HbA1c <6.5%; P<0.0001 for all). The addition of pioglitazone also significantly improved triglyceride, highdensity lipoprotein cholesterol levels, and homeostatic model assessment of insulin resistance levels, while placebo did not. The incidence of treatment-emergent adverse events was similar between the groups, and the incidence of fluid retention-related side effects by pioglitazone was low (1.5%). Conclusion: Triple therapy with the addition of 15 mg/day of pioglitazone to dapagliflozin plus metformin was well tolerated and produced significant improvements in HbA1c in patients with T2DM inadequately controlled with dapagliflozin plus metformin.

Association between the Diabetes Drug Cost and Cardiovascular Events and Death in Korea: A National Health Insurance Service Database Analysis.

BACKGRUOUND: This study aimed to investigate the long-term effects of diabetes drug costs on cardiovascular (CV) events and death. METHODS: This retrospective observational study used data from 2009 to 2018 from the National Health Insurance in Korea. Among the patients with type 2 diabetes, those taking antidiabetic drugs and who did not have CV events until 2009 were included. Patients were divided into quartiles (Q1 [lowest]-4 [highest]) according to the 2009 diabetes drug cost. In addition, the 10-year incidences of CV events (non-fatal myocardial infarction, stroke, hospitalization for heart failure, and coronary revascularization) and CV death (death due to CV events) were analyzed. RESULTS: A total of 441,914 participants were enrolled (median age, 60 years; men, 57%). CV events and death occurred in 28.1% and 8.36% of the patients, respectively. The 10-year incidences of CV events and deaths increased from Q1 to 4. After adjusting for sex, age, income, type of diabetes drugs, comorbidities, and smoking and drinking status, the risk of CV events significantly increased according to the sequential order of the cost quartiles. In contrast, the risk of CV death showed a U-shaped pattern, which was the lowest in Q3 (hazard ratio [HR], 0.953; 95% confidence interval [CI], 0.913 to 0.995) and the highest in Q4 (HR, 1.266; 95% CI, 1.213 to 1.321). CONCLUSION: Diabetes drug expenditure affects 10-year CV events and mortality. Therefore, affording an appropriate diabetes drug cost at a similar risk of CV is an independent protective factor against CV death.

Patient Understanding of Hypoglycemia in Tertiary Referral Centers.

BACKGROUND: Hypoglycemia is an important complication in the treatment of patients with diabetes. We surveyed the insight by patients with diabetes into hypoglycemia, their hypoglycemia avoidance behavior, and their level of worry regarding hypoglycemia. METHODS: A survey of patients with diabetes, who had visited seven tertiary referral centers in Daegu or Gyeongsangbuk-do, Korea, between June 2014 and June 2015, was conducted. The survey contained questions about personal history, symptoms, educational experience, self-management, and attitudes about hypoglycemia. RESULTS: Of 758 participants, 471 (62.1%) had experienced hypoglycemia, and 250 (32.9%) had experienced hypoglycemia at least once in the month immediately preceding the study. Two hundred and forty-two (31.8%) of the participants had received hypoglycemia education at least once, but only 148 (19.4%) knew the exact definition of hypoglycemia. Hypoglycemic symptoms identified by the participants were dizziness (55.0%), sweating (53.8%), and tremor (40.8%). They mostly chose candy (62.1%), chocolate (37.7%), or juice (36.8%) as food for recovering hypoglycemia. Participants who had experienced hypoglycemia had longer duration of diabetes and a higher proportion of insulin usage. The mean scores for hypoglycemia avoidance behavior and worry about hypoglycemia were 21.2±10.71 and 23.38±13.19, respectively. These scores tended to be higher for participants with higher than 8% of glycosylated hemoglobin, insulin use, and experience of emergency room visits. CONCLUSION: Many patients had experienced hypoglycemia and worried about it. We recommend identifying patients that are anxious about hypoglycemia and educating them about what to do when they develop hypoglycemic symptoms, especially those who have a high risk of hypoglycemia.

A First Case of Osteomesopyknosis in Korea.

Osteomesopyknosis is a rare sclerosing bone disorder of autosomal dominant inheritance. We report a first case of osteomesopyknosis in Korea. A 16-year old girl complained of diffuse back pain for 1 year. We performed physical examination, biochemical investigations and imaging studies. A radiograph of spine revealed rugger-jersey vertebra and sandwich vertebra. Bone specific alkaline phosphatase, osteocalcin and C-terminal telopeptides of type I collagen were normal. Only an axial skeleton involvement was shown on the whole body bone scan. This patient was diagnosed to have osteomesopyknosis. Osteomesopyknosis is characterized by normal level of bone turnover marker and an axial bone involvement. Osteomesopyknosis can be occurred in Korea and needs to be considered when patients, especially young patients, suffer from back pain and have only axial osteosclerosis.

Association between the Growth Hormone Receptor Exon 3 Polymorphism and Metabolic Factors in Korean Patients with Acromegaly.

BACKGROUND: This study investigated the association between the frequency of growth hormone receptor (GHR) exon 3 polymorphism (exon 3 deletion; d3-GHR) and metabolic factors in patients with acromegaly in Korea. METHODS: DNA was extracted from the peripheral blood of 30 unrelated patients with acromegaly. GHR genotypes were evaluated by polymerase chain reaction and correlated with demographic data and laboratory parameters. RESULTS: No patient had the d3/d3 genotype, while four (13.3%) had the d3/fl genotype, and 26 (86.7%) had the fl/fl genotype. Body mass index (BMI) in patients with the d3/fl genotype was significantly higher than in those with the fl/fl genotype (P=0.001). Age, gender, blood pressure, insulin-like growth factor-1, growth hormone, fasting plasma glucose, triglycerides, high density lipoprotein cholesterol, and low density lipoprotein cholesterol levels showed no significant differences between the two genotypes. CONCLUSION: The d3-GHR polymorphism may be associated with high BMI but not with other demographic characteristics or laboratory parameters.

The role of Nrf2: adipocyte differentiation, obesity, and insulin resistance.

Metabolic diseases, such as type 2 diabetes and obesity, are increasing globally, and much work has been performed to elucidate the regulatory mechanisms of these diseases. Nuclear factor E2-related factor 2 (Nrf2) is a basic leucine zipper transcription factor that serves as a primary cellular defense against the cytotoxic effects of oxidative stress. Recent studies have proposed a close relationship between oxidative stress and energy metabolism-associated disease. The Nrf2 pathway, as a master regulator of cellular defense against oxidative stress, has emerged as a critical target of energy metabolism; however, its effects are controversial. This review examines the current state of research on the role of Nrf2 on energy metabolism, specifically with respect to its participation in adipocyte differentiation, obesity, and insulin resistance, and discusses the possibility of using Nrf2 as a therapeutic target in the clinic.

Dimethylfumarate suppresses adipogenic differentiation in 3T3-L1 preadipocytes through inhibition of STAT3 activity.

The excessive accumulation of adipocytes contributes to the development of obesity and obesity-related diseases. The interactions of several transcription factors, such as C/EBPß, PPARγ, C/EBPα, Nrf2, and STAT3, are required for adipogenic differentiation. Dimethylfumarate (DMF), an immune modulator and antioxidant, may function as an inhibitor of STAT3 and an activator of Nrf2. This study examined whether DMF inhibits adipogenic differentiation of 3T3-L1 preadipocytes by inhibiting STAT3 or activating Nrf2. DMF suppressed 3T3-L1 preadipocyte differentiation to mature adipocytes in a dose-dependent manner as determined by Oil Red O staining. The mRNA and protein levels of adipogenic genes, including C/EBPß, C/EBPα, PPARγ, SREBP-1c, FAS, and aP2, were significantly lower in DMF-treated 3T3-L1 preadipocytes. Suppression of adipogenic differentiation by DMF treatment resulted primarily from inhibition of the early stages of differentiation. DMF inhibits clonal expansion during adipogenic differentiation through induction of a G1 cell cycle arrest. Additionally, DMF regulates cell cycle-related proteins, such as p21, pRb, and cyclin D. DMF treatment markedly inhibited differentiation medium-induced STAT3 phosphorylation and inhibited STAT3 transcriptional activation of a reporter construct composed of four synthetic STAT3-response elements. Moreover, inhibition of endogenous Nrf2 activity using a dominant negative Nrf2 did not abolish the DMF-induced inhibition of adipogenic differentiation of 3T3-L1 preadipocytes. In summary, DMF is a negative regulator of adipogenic differentiation based on its regulation of adipogenic transcription factors and cell cycle proteins. This negative regulation by DMF is mediated by STAT3 inhibition, but is unlikely to involve Nrf2 activation.

Serum irisin levels in new-onset type 2 diabetes.

AIMS: Irisin has been identified as a novel myokine that drives brown-fat-like conversion of white adipose tissue. In this cross-sectional study, we investigated whether serum irisin levels are decreased in patients with type 2 diabetes (T2D) compared with control subjects with normal glucose tolerance (NGT), and assessed the association between serum irisin levels and various metabolic parameters. METHODS: The study population was selected from a population-based study and included 104 subjects with NGT and 104 subjects with new-onset T2D. Serum irisin and adiponectin levels and metabolic parameters were measured. Multivariate logistic regression analysis was performed to assess the association between irisin levels and newly diagnosed T2D. RESULTS: Serum irisin levels were significantly decreased in the new-onset T2D group compared with the NGT control group (p=0.003). In a multivariable model adjusted for various metabolic parameters, increased irisin levels were associated with reduced odds (OR 0.64, 95% CI 0.47-0.88, p=0.006) of prevalent newly diagnosed T2D. Furthermore, multiple regression analysis showed that 2 h plasma glucose was an independent variable influencing serum irisin levels (p=0.004). CONCLUSION: In the present study, we found that serum irisin levels were decreased in T2D patients and inversely associated with newly diagnosed T2D, suggesting that irisin may play a crucial role in glucose intolerance and T2D.

Association of the DDAH2 gene polymorphism with type 2 diabetes and hypertension.

AIMS: The aim of this study was to investigate whether the polymorphism of DDAH2 is associated with type 2 diabetes and hypertension in Korean population. METHODS: Total 605 subjects were included in this study: 403 patients with type 2 diabetes and 202 non-diabetic control subjects. The SNP rs805304 and rs2272592 in DDAH2 were analyzed. We examined the association of SNP rs805304 and rs2272592 in DDAH2 with type 2 diabetes and hypertension. RESULTS: SNP rs2272592 was significantly associated with type 2 diabetes (P<0.001) while SNP rs805304 was not (P=0.716). We observed that the prevalence of the AG+GG genotypes were significantly greater than AA homozygotes in type 2 diabetes (AA vs AG+GG; OR 20.74, 95% CI 6.48-66.35, P<0.001). Significance was maintained after adjusting for age, sex, BMI, DBP and BUN (OR 21.03, 95% CI 2.83-151.14, P=0.003). Both SNP rs805304 and rs2272592 in DDAH2 were not significantly associated with hypertension. CONCLUSIONS: In the present study, we found that SNP rs2272592 in DDAH2 is associated with type 2 diabetes but SNP rs805304 in DDAH2 is not. DDAH2 SNP rs2272592 AG+GG genotypes are associated with genetic susceptibility to type 2 diabetes in Korean population.

Mediation of glucolipotoxicity in INS-1 rat insulinoma cells by small heterodimer partner interacting leucine zipper protein (SMILE).

Sustained elevations of glucose and free fatty acid concentration have deleterious effects on pancreatic beta cell function. One of the hallmarks of such glucolipotoxicity is a reduction in insulin gene expression, resulting from decreased insulin promoter activity. Sterol regulatory element binding protein-1c (SREBP-1c), a lipogenic transcription factor, is related to the development of beta cell dysfunction caused by elevated concentrations of glucose and free fatty acid. Small heterodimer partner (SHP) interacting leucine zipper protein (SMILE), also known as Zhangfei, is a novel protein which interacts with SHP that mediates glucotoxicity in INS-1 rat insulinoma cells. Treatment of INS-1 cells with high concentrations of glucose and palmitate increased SREBP-1c and SMILE expression, and decreased insulin gene expression. Adenovirus-mediated overexpression of SREBP-1c in INS-1 cells induced SMILE expression. Moreover, adenovirus-mediated overexpression of SMILE (Ad-SMILE) in INS-1 cells impaired glucose-stimulated insulin secretion as well as insulin gene expression. Ad-SMILE overexpression also inhibited the expression of beta-cell enriched transcription factors including pancreatic duodenal homeobox factor-1, beta cell E box transactivator 2 and RIPE3b1/MafA, in INS-1 cells. Finally, in COS-1 cells, expression of SMILE inhibited the insulin promoter activity induced by these same beta-cell enriched transcription factors. These results collectively suggest that SMILE plays an important role in the development of beta cell dysfunction induced by glucolipotoxicity.

Relationship of 11ß-hydroxysteroid dehydrogenase type 1 and hexose-6-phosphate dehydrogenase gene polymorphisms with metabolic syndrome and type 2 diabetes.

11ß-Hydroxysteroid dehydrogenase type 1 (HSD11B1), which converts inactive glucocorticoid to active glucocorticoid, plays a critical role in the pathogenesis of visceral obesity, metabolic syndrome, and diabetes. Hexose-6-phosphate dehydrogenase (H6PD) supplies a crucial cofactor, reduced nicotinamide adenine dinucleotide phosphate (NADPH), which allows HSD11B1 to maintain reductase activity. The association of common SNPs in HSD11B1 [IVS3-29G/T (rs12086634), IVS4-11120A/G (rs1000283)] and H6PD [R453Q (rs6688832), P554L (rs17368528)], either separately or combined, with type 2 diabetes and metabolic syndrome was examined in 427 Korean subjects with type 2 diabetes and in 358 nondiabetic Korean subjects. HSD11B1 polymorphisms (rs12086634 and rs1000283) were associated with metabolic syndrome among type 2 diabetic subjects and an H6PD polymorphism (rs17368528) was a risk factor for metabolic syndrome in nondiabetic subjects. However, no significant association of these SNPs with type 2 diabetes and metabolic syndrome was found after considering the multiple comparisons in the total study population. In conclusion, HSD11B1 and H6PD polymorphisms may not be associated with type 2 diabetes and metabolic syndrome. Further investigation of the role of these gene polymorphisms on the pathogenesis of metabolic syndrome is required.

Relationship between cardiovascular autonomic neuropathy and coronary artery calcification in patients with type 2 diabetes.

To test the hypothesis that cardiovascular autonomic neuropathy (CAN) in Type 2 diabetes is a risk factor of coronary artery calcification (CAC), in this cross-sectional study, 118 patients (60 males, 58 females) with type 2 diabetes mellitus were randomly selected from the diabetes clinic of Kyungpook National University Hospital, Daegu, Korea, between January, 2008 and September, 2008. The subjects, whose mean age was 56.9+/-1.1 years, were tested for CAN by Ewing's method which employs five non-invasive tests of autonomic function. The coronary calcium score (CCS) was determined by Multi Detector-row Computed Tomography (MDCT). Statistical analysis was performed by using SPSS 13.0 (SPSS, Inc., Chicago,-Illinois). CAN was found in 31/118 (26.3%) patients. Compared to the patients without CAN, the patients with CAN were significantly older and had significantly higher triglyceride levels, blood pressure, pulse pressure, fasting c-peptide levels, CAN scores, and log-transformed coronary calcium scores [ln(CCS+1)]. The CAN scores correlated positively with ln(CCS+1) values (r = 0.214; P = 0.028). Multiple regression analysis using ln(CCS+1) as a dependent variable showed that CAN score (beta coefficient 0.623, 95% CI 0.059 approximately 1.188, P = 0.031) associated independently with ln(CCS+1). In conclusion, CAN was associated independently with CAC, which suggests that CAN is a risk factor of coronary atherosclerosis in patients with type 2 diabetes. This may help to explain the excess cardiovascular mortality seen in diabetic patients with CAN.

Impact of ENPP1 and MMP3 gene polymorphisms on aortic calcification in patients with type 2 diabetes in a Korean population.

AIMS: We investigated whether gene polymorphisms of Ecto-nucleotide pyrophosphatase/phosphodiesterase 1 (ENPP1) and matrix metalloproteinase 3 (MMP3) are associated with increased vascular calcification in patients with type 2 diabetes (T2D) and evaluated whether serum MMP3 and osteoprotegerin (OPG) levels are related to calcification. METHODS: This study included 464 subjects: 269 patients with T2D and 195 healthy controls in South Korea. We genotyped subjects for four single nucleotide polymorphisms (SNPs): ENPP1 K121Q, ENPP1 A/G+1044TGA, MMP3 -709A>G and MMP3 -1475G>A. The presence or absence of calcifications in the aortic arch was assessed by plain chest radiography. RESULTS: The SNPs ENPP1 K121Q and MMP3 -709A>G showed significant associations with T2D (P=0.001 and P=0.004). The SNP ENPP1 K121Q showed a significant association with aortic arch calcification in T2D (P=0.036). Serum OPG levels were significantly higher in T2D patients than in the control group (P<0.001). However, serum MMP3 levels were significantly lower in T2D patients than in the control group (P<0.001). CONCLUSIONS: Our study demonstrates that the ENPP1 K121Q and MMP3 -709A>G polymorphisms are associated with T2D, and that the ENPP1 Q allele is associated with increased aortic arch calcification in a Korean population.

Novel mutation of aquaporin-2 gene in a patient with congenital nephrogenic diabetes insipidus.

Congenital nephrogenic diabetes insipidus (CNDI) is a rare inherited disease, characterized by an inability of the kidney to concentrate urine in response to vasopressin. Three different inheritance patterns have been described, i.e., the X-linked recessive form associated with arginine vasopressin V2 receptor (AVPR2) gene mutations, the autosomal recessive and dominant forms of CNDI associated with mutations in the aquaporin-2 (AQP2) gene encoding the vasopressin-regulated water channel of the renal collecting duct. Our case is an 18-year-old male patient who complained of severe polyuria since his infancy. But his developmental and growth status were normal. He was diagnosed as CNDI by water deprivation test and genomic DNA sequencing, which revealed high plasma AVP levels but persistently low urine osmolalities to 6 h-water deprivation and the novel missense mutation S216F in exon4 of the AQP2 gene. Immunohistochemistry of renal biopsied tissue revealed that most of the AQP2 labeling was seen intracellularly in a dotted pattern in the collecting duct principal cells. Immunoblotting of urine samples revealed significantly decreased urinary excretion of AQP2 (approximately 7% of normal control). Here, we report a new case of CNDI associated with the novel missense mutation of the AQP2 gene.