Questionnaire-Based Survey of Diabetes Self-Care Activities and Barriers among Young Korean Adults with Early-Onset Diabetes.

PURPOSE: Self-management of diabetes is a significant challenge. This study aimed to assess diabetes self-care activities and barriers among Korean young adults with diabetes mellitus. MATERIALS AND METHODS: This study recruited 209 Korean adults with diabetes, with an onset age of 20-39 years, from four university hospitals. Demographic characteristics and the Summary of Diabetes Self-Care Activities (SDSCA) measure and Diabetes Self-Care Barriers Assessment Scale for Older Adults (DSCB-OA) scores were assessed using questionnaires. RESULTS: The average age of study participants was 32.9±6.1 years. Their self-care activities, including adherence to recommended diabetes medication (5.6±2.4) and number of diabetes pills (5.5±2.3) in the SDSCA measure, were the most well-performed activities among all domains. Responses to inspection of the inside of shoes in the foot care activity (0.8±1.5) and specific exercise sessions in the exercise activity (1.6±1.9) reflected poor levels of compliance. According to the DSCB-OA questionnaire, the mean diabetes self-care barrier of DSCB-OA was 20.6±5.0 of total score 45. The greater perceived barriers to self-care on the DSCB-OA were having difficulty exercising regularly (1.9±0.7) and eating three meals and snacks leading to weight gain (1.9±0.8). CONCLUSION: Young adults with early-onset diabetes showed a greater barrier to regular exercise and poor compliance with foot care and blood sugar testing. Healthcare providers must strengthen their relationship with young adults with diabetes to provide more education and guidelines for lifestyle modification focused on exercise and to promote higher compliance with diabetic self-care activities for improving clinical outcomes.

Unmet Needs of Patients With Chronic Urticaria: A Survey in Korea.

Chronic urticaria (CU) is a common problem with a high disease burden that has a significant negative impact on quality of life. Many patients are undertreated, and awareness of management strategies is low among clinicians. The present study aimed to improve understanding of CU from the patients' perspective, including the disease burden and current healthcare system use. Adult patients who presented to our referral hospital for CU treatment completed self-report questionnaires about demographics, clinical characteristics of CU, the impact of CU on daily life, unmet needs, and the history of medical service usage. This self-report survey included 127 participants (females, 57.0%; mean age, 42.0 ± 13.6 years; mean CU duration, 1.8 ± 3.4 years); 51.6% reported frequent discomfort with CU in daily life, including 44.1% of those who reported a good response to medication. More than half of the respondents reported a depressed mood and anxiety. Although 46.4% of the respondents reported that urticaria completely disappeared while on medication, only 10% were satisfied with the CU management provided by primary care hospitals. The principal cause of dissatisfaction was that they did not know the cause of CU (68.4% of patients). In total, 55% of the patients visited 2 or more hospitals before presenting to our referral hospital and 6.3% had tried folk remedies. In conclusion, most patients report that CU is not adequately controlled. Therefore, in addition to appropriate medication, information on the cause of CU, long-term treatment plan, medication safety, and expected prognosis is required to meet patients' needs.

Phloretin Ameliorates Succinate-Induced Liver Fibrosis by Regulating Hepatic Stellate Cells.

BACKGRUOUND: Hepatic stellate cells (HSCs) are the major cells which play a pivotal role in liver fibrosis. During injury, extracellular stimulators can induce HSCs transdifferentiated into active form. Phloretin showed its ability to protect the liver from injury, so in this research we would like to investigate the effect of phloretin on succinate-induced HSCs activation in vitro and liver fibrosis in vivo study. METHODS: In in vitro, succinate was used to induce HSCs activation, and then the effect of phloretin on activated HSCs was examined. In in vivo, succinate was used to generated liver fibrosis in mouse and phloretin co-treated to check its protection on the liver. RESULTS: Phloretin can reduce the increase of fibrogenic markers and inhibits the proliferation, migration, and contraction caused by succinate in in vitro experiments. Moreover, an upregulation of proteins associated with aerobic glycolysis occurred during the activation of HSCs, which was attenuated by phloretin treatment. In in vivo experiments, intraperitoneal injection of phloretin decreased expression of fibrotic and glycolytic markers in the livers of mice with sodium succinate diet-induced liver fibrosis. These results suggest that aerobic glycolysis plays critical role in activation of HSCs and succinate can induce liver fibrosis in mice, whereas phloretin has therapeutic potential for treating hepatic fibrosis. CONCLUSION: Intraperitoneal injection of phloretin attenuated succinate-induced hepatic fibrosis and alleviates the succinate-induced HSCs activation.

Assessing Quality of Life in Patients With Chronic Urticaria Through Comparisons With Patients Having Other Common Chronic Diseases.

BACKGROUND: Chronic urticaria (CU) is a common chronic inflammatory disease, but the burden on quality of life (QOL) has been underestimated. OBJECTIVE: To compare QOL among patients with CU and those with other chronic diseases. METHODS: Adult patients who visited a referral hospital for CU were enrolled. Patients completed self-reported questionnaires including clinical characteristics of chronic urticaria and the short form 36 health survey. As a comparative group, patients with rheumatoid arthritis, patients with diabetes treated with insulin, patients on maintenance hemodialysis, and healthy controls were enrolled and completed the short form 36 health survey. RESULTS: In all, 119 patients with CU were enrolled and their short form 36 scores were not significantly different from those of healthy controls. However, patients with CU with poor responses to treatment showed impaired QOL to a degree similar to that of patients with rheumatoid arthritis or insulin-treated diabetes. The patients with CU showed various clinical characteristics with respect to treatment response, accompanying symptoms, and aggravating factors. Among these factors, pain at the urticarial lesion and symptom aggravation during exercise and after the consumption of certain foods were related with lower QOL. CONCLUSIONS: Patients with CU with an incomplete response to treatment had significantly low QOL, comparable to that of patients with rheumatoid arthritis or insulin-treated diabetes. To minimize this effect, clinicians should aim to control symptoms and aggravating factors.

Drosophila pain sensitization and modulation unveiled by a novel pain model and analgesic drugs.

In mammals, pain is regulated by the combination of an ascending stimulating and descending inhibitory pain pathway. It remains an intriguing question whether such pain pathways are of ancient origin and conserved in invertebrates. Here we report a new Drosophila pain model and use it to elucidate the pain pathways present in flies. The model employs transgenic flies expressing the human capsaicin receptor TRPV1 in sensory nociceptor neurons, which innervate the whole fly body, including the mouth. Upon capsaicin sipping, the flies abruptly displayed pain-related behaviors such as running away, scurrying around, rubbing vigorously, and pulling at their mouth parts, suggesting that capsaicin stimulated nociceptors in the mouth via activating TRPV1. When reared on capsaicin-containing food, the animals died of starvation, demonstrating the degree of pain experienced. This death rate was reduced by treatment both with NSAIDs and gabapentin, analgesics that inhibit the sensitized ascending pain pathway, and with antidepressants, GABAergic agonists, and morphine, analgesics that strengthen the descending inhibitory pathway. Our results suggest Drosophila to possess intricate pain sensitization and modulation mechanisms similar to mammals, and we propose that this simple, non-invasive feeding assay has utility for high-throughput evaluation and screening of analgesic compounds.

Gemigliptin Alleviates Succinate-Induced Hepatic Stellate Cell Activation by Ameliorating Mitochondrial Dysfunction.

BACKGRUOUND: Dipeptidyl peptidase-4 inhibitors (DPP-4Is) are used clinically as oral antidiabetic agents. Although DPP-4Is are known to ameliorate liver fibrosis, the protective mechanism of DPP-4Is in liver fibrosis remains obscure. In this study, gemigliptin was used to investigate the potential of DPP-4Is to alleviate the progression of liver fibrosis. METHODS: To clarify the effects and mechanisms of gemigliptin, we conducted various experiments in LX-2 cells (immortalized human hepatic stellate cells [HSCs], the principal effectors of hepatic fibrogenesis), which were activated by succinate and exhibited elevated expression of α-smooth muscle actin, collagen type 1, and pro-inflammatory cytokines and increased cell proliferation. In vivo, we examined the effects and mechanisms of gemigliptin on a high-fat, high-cholesterol-induced mouse model of nonalcoholic steatohepatitis (NASH). RESULTS: Gemigliptin decreased the expression of fibrogenesis markers and reduced the abnormal proliferation of HSCs. In addition, gemigliptin reduced the succinate-induced production of mitochondrial reactive oxygen species (ROS), intracellular ROS, and mitochondrial fission in HSCs. Furthermore, in the mouse model of NASH-induced liver fibrosis, gemigliptin alleviated both liver fibrosis and mitochondrial dysfunction. CONCLUSION: Gemigliptin protected against HSC activation and liver fibrosis by alleviating mitochondrial dysfunction and ROS production, indicating its potential as a strategy for preventing the development of liver disease.

Transition metal-catalyzed regioselective functionalization of carbazoles and indolines with maleimides.

The directing group-assisted regioselective C-H activation of carbazoles and indolines is achieved via transition metal-catalyzed reactions. This C-H functionalization protocol provides a rapid approach to install diversely functionalized succinimide groups at the C-1 position of the carbazole moiety. In addition, this protocol demonstrates the intrinsic reactivity of indolines in providing C-2 succinimide-substituted indoles via cascade direct oxidation and C-H functionalization. This protocol also provides C-7 succinimide-substituted indolines under mild reaction conditions. The features of this reaction include a wide substrate scope and excellent regioselectivity for the installation of the succinimide moiety on biologically interesting molecules.

The Effects of Irisin on the Interaction between Hepatic Stellate Cell and Macrophage in Liver Fibrosis.

BACKGRUOUND: Hepatic stellate cells (HSCs) are the central players interacting with multiple cell types in liver fibrosis. The crosstalk between HSCs and macrophages has recently become clearer. Irisin, an exercise-responsive myokine, was known to have a potentially protective role in liver and renal fibrosis, especially in connection with stellate cells. This study investigated the effects of irisin on the interaction between HSCs and macrophages. METHODS: Tamm-Horsfall protein-1 (THP-1) human monocytes were differentiated into macrophages, polarized into the inflammatory M1 phenotype with lipopolysaccharide. Lieming Xu-2 (LX-2) cells, human HSCs, were treated with conditioned media (CM) from M1 macrophages, with or without recombinant irisin. HSCs responses to CM from M1 macrophages were evaluated regarding activation, proliferation, wound healing, trans-well migration, contractility, and related signaling pathway. RESULTS: CM from M1 macrophages significantly promoted HSC proliferation, wound healing, transwell migration, and contractility, but not activation of HSCs. Irisin co-treatment attenuated these responses of HSCs to CM. However, CM and irisin treatment did not induce any changes in HSC activation. Further, irisin co-treatment alleviated CM-induced increase of phopho-protein kinase B (pAKT), matrix metalloproteinase-9 (MMP-9), and tissue inhibitor of metalloproteinases-1 (TIMP-1). CONCLUSION: These findings suggested that irisin may play a protective role in the pathogenesis of liver fibrosis, especially when working in the crosstalk between HSCs and macrophages.

Real-world comparison of mono and dual combination therapies of metformin, sulfonylurea, and dipeptidyl peptidase-4 inhibitors using a common data model: A retrospective observational study.

ABSTRACT: The comparative effectiveness of oral hypoglycemic agents on glycemic control and chronic complications in clinical practice is unknown in Korea. This study aimed to compare glycemic control and the incidence of hypoglycemia and chronic complications among adult patients with type 2 diabetes prescribed metformin, dipeptidyl peptidase-4 inhibitors (DPP4I), and sulfonylurea (SU) as monotherapy or dual combination therapy.We retrospectively analyzed propensity-matched cohort data from 3 national university hospitals in Korea. All electronic health records were transformed into a unified Observational Medical Outcomes Partnership Common Data Model and analyzed using ATLAS, an open-source analytical tool, and R software. Glycemic control was assessed as the first observation of a reduction in glycosylated hemoglobin (HbA1c) level below 7% after prescription of the drug. Differences in the incidence of chronic complications were compared based on the first observation of each complication. Glycemic control and chronic complications were evaluated in patients who maintained the same prescription for at least 3 and 12 months, respectively.Patients who received metformin had lower hazard of reaching HbA1c levels below 7% as compared with those who received SU, and had higher hazard compared with those who received DPP4I (hazard ratio [HR], 0.86; 95% confidence interval [CI], 0.75-0.98; and HR, 1.68; 95% CI, 1.42-1.99, respectively). The incidence of hypoglycemia was significantly higher in the SU group than in the metformin and DPP4I groups (metformin vs SU; HR, 0.30; 95% CI, 0.21-0.43; SU vs DPP4I; HR, 4.42; 95% CI, 2.35-8.31). Metformin + DPP4I had similar hazard of reaching HbA1c levels below 7% compared with metformin + SU (HR, 1.19; 95% CI, 0.99-1.43) and the incidence of hypoglycemia was significantly lower in the metformin + DPP4I group (HR 0.13; 95% CI 0.05-0.30). There was no significant difference in the analysis of the occurrence of chronic complications.SU followed by metformin was effective, and both drugs showed an increased hazard of reaching HbA1c levels below 7% compared with DPP4I. Metformin + DPP4I is comparatively effective for HbA1c level reduction below 7% compared with metformin + SU. Hypoglycemia was high in the SU-containing therapy.

Questionnaire-based Survey of Demographic and Clinical Characteristics, Health Behaviors, and Mental Health of Young Korean Adults with Early-onset Diabetes.

BACKGROUND: The incidence of early-onset diabetes is increasing among young adults. However, there are limited data on the characteristics and management of young Korean adults with diabetes. This study assessed the clinical and demographic characteristics, health behaviors, and mental health among young Korean adults with diabetes mellitus. METHODS: This cross-sectional study included young Korean adults with diabetes (n = 225) with an onset age of 20-39 years from four university hospitals. Demographic characteristics, management of diabetes, and mental health were assessed using a questionnaire survey. RESULTS: Type 2 diabetes was the most common type (73.3%), and 13.8% of participants were classified as other types or unknown. Approximately, 64.7% of participants had a strong family history of diabetes, and 76% had treatment within three months of diagnosis. Approximately, 11.1% of participants had diabetic complications; 39.1% of participants received insulin injections, including oral anti-diabetic medications. Additionally, 30.4% were smokers, and only 28% had active physical activity; 26.5% of participants had >3 hours of screen time. One third of participants never had breakfast, and 60.5% went out to eat at least three times a week. Half of the participants showed moderate to severe stress perception, and 21.4% of patients had moderate to severe levels of depression based on the Korean version of Beck Depression Inventory score. CONCLUSION: Early-onset diabetes was associated with a strong family history and early insulin treatment. Young adults with diabetes had poor health behaviors and frequent mental depression. These findings suggest the necessity of health policies for improving health behaviors and mental distress.

Irisin Regulates the Functions of Hepatic Stellate Cells.

BACKGROUND: Hepatic stellate cells (HSCs) are known to play a fundamental role in the progression of liver fibrosis. Once HSCs are activated, they are involved in proliferation, migration, and contractility which are characteristics of liver fibrogenesis. Recent studies have shown that irisin, a myokine secreted during physical exercise, has a protective effect in various metabolic diseases, especially in renal fibrosis. However, whether irisin is involved in HSC activation and other processes associated with liver fibrosis has not yet been investigated. In this study, we reveal the role of irisin in HSC activation as well as in proliferation, migration, and contractile properties of HSCs in vitro. METHODS: LX-2 cells, immortalized human HSCs, were treated with transforming growth factor beta 1 (TGF-ß1), a core regulator of HSC fibrosis, with or without irisin, and markers of the aforementioned processes were analyzed. Further, an inflammatory response was stimulated with TGF-ß1 and lipopolysaccharide (LPS) in combination with irisin and the expression of cytokines was measured. RESULTS: Recombinant irisin significantly suppressed the expression of TGF-ß1-stimulated fibrosis markers including alpha-smooth muscle actin and collagen type 1 alpha 1 and prevented the TGF-ß1-induced proliferation, migration, and contractility of LX-2 cells. Additionally, irisin ameliorated the production of interleukin-6 (IL-6) and IL-1ß induced by TGF-ß1 and LPS treatments. CONCLUSION: These findings suggested that irisin potently improved the progression of hepatic fibrosis by regulating HSC activation, proliferation, migration, contractility, and HSC-mediated production of inflammatory cytokine.

Gliclazide monotherapy increases risks of all-cause mortality and has similar risk of acute myocardial infarction and stroke with glimepiride monotherapy in Korean type 2 diabetes mellitus.

Sulphonylureas (SUs) subclasses have different risks of all-cause mortality, acute myocardial infarction (AMI), and stroke. Therefore, we assessed these risks in patients with type 2 diabetes mellitus administered gliclazide, glimepiride, or metformin monotherapy with retrospective cohort study design. Total 195,235 subjects were included in the study who were ≥20 years' old and prescribed monotherapy for at least 1 year as a first-line therapy for incident diabetes from January 01, 2009 to December 31, 2013 in the National Health Insurance Service Claim data. Incidence and hazard ratios (HRs) of all-cause mortality, AMI, and stroke were compared with glimepiride monotherapy as a reference. Gliclazide monotherapy increased all-cause mortality compared with glimepiride monotherapy. However, the gliclazide and glimepiride groups showed no difference in AMI and stroke incidences. In line with previous studies, metformin monotherapy showed significant clinical benefits in reducing risks of all-cause mortality, AMI, and stroke compared with glimepiride. This population-based cohort study suggested that gliclazide increases risks of all-cause mortality and has similar risk of AMI and stroke with gliclazide monotherapy in Korean.

Empagliflozin dilates the rabbit aorta by activating PKG and voltage-dependent K+ channels.

We investigated the vasodilatory effects of empagliflozin (a sodium-glucose co-transporter 2 inhibitor) and the underlying mechanisms using rabbit aorta. Empagliflozin induced vasodilation in a concentration-dependent manner independently of the endothelium. Likewise, pretreatment with the nitric oxide synthase inhibitor L-NAME or the SKca inhibitor apamin together with the IKca inhibitor TRAM-34 did not impact the vasodilatory effects of empagliflozin. Pretreatment with the adenylyl cyclase inhibitor SQ22536 or a guanylyl cyclase inhibitor ODQ or a protein kinase A (PKA) inhibitor KT5720 also did not alter the vasodilatory response of empagliflozin. However, the vasodilatory effects of empagliflozin were significantly reduced by pretreatment with the protein kinase G (PKG) inhibitor KT5823. Although application of the ATP-sensitive K+ (KATP) channel inhibitor glibenclamide, large-conductance Ca2+-activated K+ (BKCa) channel inhibitor paxilline, or inwardly rectifying K+ (Kir) channel inhibitor Ba2+ did not impact the vasodilatory effects of empagliflozin, pretreatment with the voltage-dependent K+ (Kv) channel inhibitor 4-AP reduced the vasodilatory effects of empagliflozin. Pretreatment with DPO-1 (Kv1.5 channel inhibitor), guangxitoxin (Kv2.1 channel inhibitor), or linopirdine (Kv7 channel inhibitor) had little effect on empagliflozin-induced vasodilation. Application of nifedipine (L-type Ca2+ channel inhibitor) or thapsigargin (sarco-endoplasmic reticulum Ca2+-ATPase pump inhibitor) did not impact empagliflozin-induced vasodilation. Therefore, empagliflozin induces vasodilation by activating PKG and Kv channels.

The vasodilatory effect of gemigliptin via activation of voltage-dependent K+ channels and SERCA pumps in aortic smooth muscle.

This study investigated the vasodilatory effects and acting mechanism of gemigliptin, a dipeptidyl peptidase-4 (DPP-4) inhibitor. Tests were conducted in aortic rings pre-contracted with phenylephrine. Gemigliptin induced dose-dependent vasodilation of the aortic smooth muscle. Several pre-treatment groups were used to investigate the mechanism of action. While pre-treatment with paxilline, a large-conductance Ca2+-activated K+ channel inhibitor, glibenclamide, an ATP-sensitive K+ channel inhibitor, and Ba2+, an inwardly rectifying K+ channel inhibitor, had no impact on the vasodilatory effect of gemigliptin, pre-treatment with 4-aminopyridine, a voltage-dependent K+ (Kv) channel inhibitor, effectively attenuated the vasodilatory action of gemigliptin. In addition, pre-treatment with sarcoplasmic/endoplasmic reticulum Ca2+-ATPase (SERCA) pump inhibitors thapsigargin and cyclopiazonic acid significantly reduced the vasodilatory effect of gemigliptin. cAMP/PKA-related or cGMP/PKG-related signaling pathway inhibitors, including adenylyl cyclase inhibitor SQ 22536, PKA inhibitor KT 5720, guanylyl cyclase inhibitor ODQ, and PKG inhibitor KT 5823 did not alter the vasodilatory effect of gemigliptin. Similarly, elimination of the endothelium and pre-treatment with a nitric oxide (NO) synthase inhibitor (L-NAME) or small- and intermediate-conductance Ca2+-activated K+ channels (apamin and TRAM-34, respectively) did not change the gemigliptin effect. These findings suggested that gemigliptin induces vasodilation through the activation of Kv channels and SERCA pumps independent of cAMP/PKA-related or cGMP/PKG-related signaling pathways and the endothelium. Therefore, caution is required when prescribing gemigliptin to the patients with hypotension and diabetes.

Comparison of the predictive validity of three fall risk assessment tools and analysis of fall-risk factors at a tertiary teaching hospital.

AIMS AND OBJECTIVES: The main purpose of this study was to identify the best fall-risk assessment tool, among the Morse Fall Scale, the Johns Hopkins fall-risk Assessment Tool and the Hendrich II fall-risk Model, for a tertiary teaching hospital. The study also analysed fall-risk factors in the hospital, focusing on the items of each fall assessment tool. METHODS: Data on falls were obtained from the patient safety reports and electronic nursing records of a tertiary teaching hospital. A retrospective study was conducted to compare the sensitivity, specificity, area under the curve, positive predictive value, negative predictive value, Youden index and accuracy of the Morse Fall Scale, the Johns Hopkins fall-risk Assessment Tool and the Hendrich II fall-risk Model. This study was conducted according to the Strengthening the Reporting of Observational Studies in Epidemiology guideline for reporting case-control studies. RESULTS: By analysing the association between falls and the items included in the three tools, we identified significant fall-risk factors such as gait, dizziness or vertigo, changes in mental status, impulsivity, history of falling, elimination disorder, drugs affecting falls, and depression. CONCLUSIONS: The Hendrich II fall-risk Model had the best predictive performance for falls of the three tools, considering the highest in the area under the curve and the Youden index that comprehensively analysed sensitivity and specificity, while the Johns Hopkins fall-risk Assessment Tool had the highest accuracy. The most significant fall-risk predictors are gait, dizziness or vertigo, change in mental state, and history of falling. RELEVANCE TO CLINICAL PRACTICE: To improve the fall assessment performance of the Morse Fall Scale at the study hospital, we propose that it be supplemented with four most significant fall-risk predictors identified in this study.

Repeated Dry Sauna Therapy Improves Quality of Life in Obese Korean People.

BACKGROUND: Dry sauna treatments improve the quality of life for chronic pain, congestive heart failure, and type 2 diabetes patients. This study aimed to determine whether dry sauna therapy improved the quality of life of obese people. METHODS: A total of 38 consecutive participants aged over 20 years with a body mass index of ≥25 kg/m2 were recruited for the study. The participants were treated with a 90°C dry sauna for 15 minutes, twice daily for 4 consecutive days. To assess the quality of life, all participants completed the 5 level EQ-5D questionnaires and the EQ-Visual Analog Scale. Study parameters were measured on the same day prior to commencing the sauna sessions in a fasted state and 2 days after the last sauna session. RESULTS: The average age was 62.3±9.5 years; 84.2% of the participants were female. The mean body mass index was 28.5±2.4 kg/m2. Dry sauna significantly improved the mean 5 level EQ-5D index scores from 0.83±0.12 to 0.89±0.11 and increased the mean EQ-Visual Analog Scale from 79.0±15.2 to 91.1±9.7. However, there were no significant changes in body mass index, blood pressure, heart rate, or body composition before and after the 8-session sauna therapy. CONCLUSION: Dry sauna improved the health-related quality of life of obese patients without adverse events. Further clinical studies in larger study populations are needed to verify these findings and provide concrete evidence for obesity treatment.

Histone Deacetylase 9: Its Role in the Pathogenesis of Diabetes and Other Chronic Diseases.

As a member of the class IIa histone deacetylases (HDACs), HDAC9 catalyzes the deacetylation of histones and transcription factors, commonly leading to the suppression of gene transcription. The activity of HDAC9 is regulated transcriptionally and post-translationally. HDAC9 is known to play an essential role in regulating myocyte and adipocyte differentiation and cardiac muscle development. Also, recent studies have suggested that HDAC9 is involved in the pathogenesis of chronic diseases, including cardiovascular diseases, osteoporosis, autoimmune disease, cancer, obesity, insulin resistance, and liver fibrosis. HDAC9 modulates the expression of genes related to the pathogenesis of chronic diseases by altering chromatin structure in their promotor region or reducing the transcriptional activity of their respective transcription factors. This review summarizes the current knowledge of the regulation of HDAC9 expression and activity. Also, the roles of HDAC9 in the pathogenesis of chronic diseases are discussed, along with potential underlying mechanisms.