Association of pooled cohort risk scores with vascular inflammation and coronary artery calcification in Korean adults

OBJECTIVES

A new pooled cohort risk equation to estimate atherosclerotic cardiovascular disease (CVD) risk was recently published, but the equation is based primarily on data from Caucasian populations. The relationship of this new risk scoring system with vascular inflammation and calcification has yet to be examined.

METHODS

A total of 74 participants were retrospectively selected based on inclusion and exclusion criteria. All participants underwent (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET) and multi-detector computed tomography (MDCT) examination in the Korea University Guro Hospital between June 2009 and May 2013. Vascular inflammation of the carotid artery was measured as target-to-background ratio (TBR) using (18)F-FDG-PET/CT and coronary artery calcification was quantified as Agatston score by MDCT.

RESULTS

Agatston scores were not significantly associated with any metabolic risk factors, but maximum TBR values exhibited a significant positive correlation with body mass index (r=0.31, P=0.01), waist circumference (r=0.42, P<0.01), waist-to-hip ratio (r=0.49, P<0.01), and systolic (r=0.35, P<0.01) and diastolic blood pressure (r=0.39, P<0.01). Furthermore, maximum TBR values were significantly correlated with serum high-sensitivity C-reactive protein (hsCRP) levels (r=0.26, P=0.03), whereas Agatston scores had no correlation. When pooled cohort risk equation scores were divided into incremental tertiles, age, waist circumference, waist-to-hip ratio and systolic blood pressure showed significant incremental trends. In particular, pooled cohort risk scores exhibited a significant positive correlation with maximum TBR values (r=0.35, P<0.01), but not with Agatston scores (r=0.11, P=0.34).

CONCLUSIONS

The pooled cohort risk equation exhibited significant positive correlations with vascular inflammation but not with calcification in Asian subjects without CVD, suggesting that this novel risk equation may detect early inflammatory changes preceding the structural modification of vessel walls.

The Impact of Organokines on Insulin Resistance, Inflammation, and Atherosclerosis

Immoderate energy intake, a sedentary lifestyle, and aging have contributed to the increased prevalence of obesity, sarcopenia, metabolic syndrome, type 2 diabetes, and cardiovascular disease. There is an urgent need for the development of novel pharmacological interventions that can target excessive fat accumulation and decreased muscle mass and/or strength. Adipokines, bioactive molecules derived from adipose tissue, are involved in the regulation of appetite and satiety, inflammation, energy expenditure, insulin resistance and secretion, glucose and lipid metabolism, and atherosclerosis. Recently, there is emerging evidence that skeletal muscle and the liver also function as endocrine organs that secrete myokines and hepatokines, respectively. Novel discoveries and research into these organokines (adipokines, myokines, and hepatokines) may lead to the development of promising biomarkers and therapeutics for cardiometabolic disease. In this review, I summarize recent data on these organokines and focus on the role of adipokines, myokines, and hepatokines in the regulation of insulin resistance, inflammation, and atherosclerosis.

The synergistic impact of nonalcoholic fatty liver disease and metabolic syndrome on subclinical atherosclerosis

OBJECTIVE

Nonalcoholic fatty liver disease (NAFLD) is a well-known contributor for the development of cardiovascular disease (CVD). We examined the influence of NAFLD and metabolic syndrome (MetS) on markers of subclinical atherosclerosis, including carotid intima-media thickness (CIMT), brachial-ankle pulse wave velocity (baPWV) and ankle-brachial pressure index (ABI), after adjusting for cardiometabolic risk factors.

DESIGN

A cross-sectional study.

PATIENTS AND MEASUREMENTS

The association between NAFLD, MetS and markers of subclinical atherosclerosis was assessed in 955 participants without CVD using multiple logistic regression analysis after adjusting for multiple cardiometabolic risk variables.

RESULTS

After adjusting for age and sex, CIMT and baPWV were found to be significantly correlated with multiple cardiometabolic risk variables, whereas ABI was only associated with obesity parameters. The prevalence of NAFLD differed significantly according to the presence of subclinical atherosclerosis as defined by both CIMT and baPWV (P = 0·004 and P = 0·007, respectively). After adjusting for potential confounding factors, NAFLD or MetS was not associated with subclinical atherosclerosis as defined by CIMT and baPWV. However, individuals with both NAFLD and MetS had a significantly higher risk of subclinical atherosclerosis as defined by CIMT (OR = 2·06, 95% CI = 1·13-3·74) or baPWV (OR = 2·64, 95% CI = 1·46-4·76) compared to normal subjects, even after adjusting for potential confounders.

CONCLUSIONS

The results show that NAFLD and MetS have a synergistic impact on the subclinical atherosclerosis, which suggests that individuals with both NAFLD and MetS should be strongly advised to engage in CVD prevention strategies.

Pharmacological Modulators of Endoplasmic Reticulum Stress in Metabolic Diseases

The endoplasmic reticulum (ER) is the principal organelle responsible for correct protein folding, a step in protein synthesis that is critical for the functional conformation of proteins. ER stress is a primary feature of secretory cells and is involved in the pathogenesis of numerous human diseases, such as certain neurodegenerative and cardiometabolic disorders. The unfolded protein response (UPR) is a defense mechanism to attenuate ER stress and maintain the homeostasis of the organism. Two major degradation systems, including the proteasome and autophagy, are involved in this defense system. If ER stress overwhelms the capacity of the cell's defense mechanisms, apoptotic death may result. This review is focused on the various pharmacological modulators that can protect cells from damage induced by ER stress. The possible mechanisms for cytoprotection are also discussed.

Predictive Mortality Index for Community-Dwelling Elderly Koreans

There are very few predictive indexes for long-term mortality among community-dwelling elderly Asian individuals, despite its importance, given the rapid and continuous increase in this population. We aimed to develop 10-year predictive mortality indexes for community-dwelling elderly Korean men and women based on routinely collected clinical data.We used data from 2244 elderly individuals (older than 60 years of age) from the southwest Seoul Study, a prospective cohort study, for the development of a prognostic index. An independent longitudinal cohort of 679 elderly participants was selected from the Korean Genome Epidemiology Study in Ansan City for validation.During a 10-year follow-up, 393 participants (17.5%) from the development cohort died. Nine risk factors were identified and weighed in the Cox proportional regression model to create a point scoring system: age, male sex, smoking, diabetes, systolic blood pressure, triglyceride, total cholesterol, white blood cell count, and hemoglobin. In the development cohort, the 10-year mortality risk was 6.6%, 14.8%, 18.2%, and 38.4% among subjects with 1 to 4, 5 to 7, 8 to 9, and ≥10 points, respectively. In the validation cohort, the 10-year mortality risk was 5.2%, 12.0%, 16.0%, and 16.0% according to these categories. The C-statistic for the point system was 0.73 and 0.67 in the development and validation cohorts, respectively.The present study provides valuable information for prognosis among elderly Koreans and may guide individualized approaches for appropriate care in a rapidly aging society.

The implications of sarcopenia and sarcopenic obesity on cardiometabolic disease

The important changes in body composition associated with aging are a decline in skeletal muscle mass and an increase in body fat. Body fat distribution also changes with age; subcutaneous fat decreases and visceral abdominal fat increase, which contributes to numerous cardiometabolic diseases (CMDs) such as type 2 diabetes, dyslipidemia, and cardiovascular disease (CVD). Sarcopenia often accompanied by an increase in body fat and vice versa, a scenario termed sarcopenic obesity (SO), which might lead to the cumulative risk of both sarcopenia and obesity. However, there is still no consensus regarding the definition and consequences of SO. The lack of a unified definition for SO might contribute to inconsistent findings about the association of SO with CMD. Complex etiologies are associated with development of SO. A vicious cycle between the loss of muscle and the accumulation of ectopic fat might be associated with CMD via an intricate interplay of factors including proinflammatory cytokines, oxidative stress, mitochondrial dysfunction, insulin resistance, dietary energy, physical activity, mitochondrial dysfunction, and other factors that have yet to be identified. Moreover, recent epidemiological studies suggest that SO is related to CVD and mortality. This review focuses on the current literature with regard to the association between sarcopenia, dynapenia, and obesity, as well as their implications for CMD. The ultimate goal of this Prospects is to encourage conduct of well-designed future studies that elucidate the relationship among sarcopenia, SO, and CMD.

Circulating angiopoietin-like protein 8 (ANGPTL8) and ANGPTL3 concentrations in relation to anthropometric and metabolic profiles in Korean children: a prospective cohort study

Background

Previous studies have shown that angiopoietin-like protein 8 (ANGPTL8), also called as betatrophin, acts together with ANGPTL3 to regulate lipid metabolism, glucose metabolism, and energy homeostasis. Moreover, ANGPTL8 promotes proliferation of pancreatic β-cells and induces insulin secretion. However, there are no previous longitudinal studies in humans.

Methods

We analyzed the age- and sex-matched data of 240 normal weight and overweight Korean children from the Korean Metabolic disorders and Obesity Study in Elementary School children (K-MOSES), a prospective observational cohort study.

Results

At baseline, ANGPTL8 concentrations were positively associated with triglycerides (TG) (r = 0.168, P = 0.010), whereas ANGPTL3 levels were associated with fasting insulin (r = 0.248, P < 0.001) and the homeostasis model assessment of insulin resistance (HOMA-IR) (r = 0.197, P = 0.002). Although both ANGPTL8 and ANGPTL3 levels did not differ between children with normal weight and children with overweight, ANGPTL8 levels were increased in males compared to females (341.2 [267.4–436.5] vs. 270.2 [213.9–378.8] pg/ml, P = 0.001). In particular, there was no significant inter-relationship between circulating ANGPTL8 and ANGPTL3 concentrations in Korean boys and girls (r = −0.073, P = 0.265). Multivariate analysis showed that baseline ANGPTL8 concentrations were independently associated with future changes of serum TG levels in Korean children after adjusting for confounding factors after a 3 year follow-up period (r = −0.165, P = 0.016).

Conclusions

This longitudinal study demonstrated for the first time that baseline ANGPTL8 levels were associated with baseline and future changes in TG levels in Korean children.

C1q/TNF-Related Protein 9 (CTRP9) attenuates hepatic steatosis via the autophagy-mediated inhibition of endoplasmic reticulum stress

C1q/TNF-Related Protein (CTRP) 9, the closest paralog of adiponectin, has been reported to protect against diet-induced obesity and non-alcoholic fatty liver disease (NAFLD). However, the underlying mechanism has not been fully elucidated. We explored the protective effect of CTRP9 against hepatic steatosis and apoptosis, and identified the mechanisms through autophagy and endoplasmic reticulum (ER) stress using in vitro and in vivo experiments. Treating HepG2 cells with human recombinant CTRP9 significantly ameliorated palmitate- or tunicamycin-induced dysregulation of lipid metabolism, caspase 3 activity and chromatin condensation, which lead to reduction of hepatic triglyceride (TG) accumulation. CTRP9 treatment induced autophagy markers including LC3 conversion, P62 degradation, Beclin1 and ATG7 through AMPK phosphorylation in human primary hepatocytes. Furthermore, CTRP9 decreased palmitate- or tunicamycin-induced ER stress markers, such as eIF2α, CHOP and IRE-1, in HepG2 cells. Compound C, an AMPK inhibitor, and 3 methyladenine (3 MA), an autophagy inhibitor, canceled the effects of CTRP9 on ER stress, apoptosis and hepatic steatosis. In the livers of HFD-fed mice, adenovirus-mediated CTRP9 overexpression significantly induced AMPK phosphorylation and autophagy, whereas suppressed ER stress markers. In addition, both SREBP1-mediated lipogenic gene expression and apoptosis were significantly attenuated, which result in improvement in hepatic steatosis by overexpression of CTRP9. These results demonstrate that CTRP9 alleviates hepatic steatosis through relief of ER stress via the AMPK-mediated induction of autophagy.

Vitamin D status and associated metabolic risk factors among North Korean refugees in South Korea: a cross-sectional study

OBJECTIVE

Vitamin D deficiency is now recognised as a common health problem associated with various chronic diseases; however, it has not been fully elucidated among the minority groups. Here, we aimed to investigate the prevalence of vitamin D deficiency and its associated metabolic risk factors among North Korean refugees living in South Korea.

DESIGN

Cross-sectional analysis from the longitudinal cohort, the North Korean refugee health in South Korea (NORNS) study.

PARTICIPANTS

A total of 386 North Korean refugees aged ≥30 years, who measured serum 25-hydroxy vitamin D (25(OH)D) level.

RESULTS

The prevalence of vitamin D deficiency (25(OH)D <20 ng/mL) was 87% and no participants had an adequate vitamin D level (25(OH)D ≥30 ng/mL). Underweight participants (body mass index (BMI) <18 kg/m(2)) had significantly lower 25(OH)D levels than individuals with normal BMI (≥18.5 and<23 kg/m(2)). In the multivariate logistic regression analysis, the lowest 25(OH)D level (<10 ng/mL) was significantly associated with metabolic syndrome (OR, 6.37, 95% CI 1.34 to 30.3), high triglyceride (OR, 6.71, 95% CI 1.75 to 25.7), and low high-density lipoprotein (OR, 5.98, 95% CI 1.54 to 23.2) compared with 25(OH)D levels ≥20 ng/mL after adjusting for age, sex, season, length of residence in South Korea, physical activity and BMI.

CONCLUSIONS

Vitamin D deficiency is very common among North Korean refugees in South Korea. Despite their lower BMI, vitamin D deficiency was associated with metabolic syndrome in this population.

Obstructive sleep apnea with excessive daytime sleepiness is associated with non-alcoholic fatty liver disease regardless of visceral fat

BACKGROUND/AIMS

Obstructive sleep apnea (OSA) is associated with an increased risk of obesity and non-alcoholic fatty liver disease (NAFLD), but it remains unclear whether the risk of NAFLD is independently related to OSA regardless of visceral obesity. Thus, the aim of the present study was to examine whether OSA alone or in combination with excessive daytime sleepiness (EDS) or short sleep duration was associated with NAFLD independent of visceral fat in Korean adults.

METHODS

A total of 621 participants were selected from the Korean Genome and Epidemiology Study (KoGES). The abdominal visceral fat area (VFA) and hepatic fat components of the participants were assessed using computed tomography scans and they were then categorized into four groups depending on the presence of OSA and EDS.

RESULTS

The proportions of NAFLD were 21.1%, 18.5%, 32.4%, and 46.7% in participants without OSA/EDS, with only EDS, with only OSA, and with both OSA and EDS, respectively. A combination of OSA and EDS increased the odds ratio (OR) for developing NAFLD (OR, 2.75; 95% confidence interval [CI], 1.21 to 6.28) compared to those without OSA/EDS, and this association remained significant (OR, 2.38; 95% CI, 1.01 to 5.59) even after adjusting for VFA. In short sleepers (< 5 hours) with OSA, the adjusted OR for NAFLD was 2.50 (95% CI, 1.08 to 5.75) compared to those sleeping longer than 5 hours without OSA.

CONCLUSIONS

In the present study, OSA was closely associated with NAFLD in Korean adults. This association was particularly strong in those with EDS or short sleep duration regardless of VFA.

Body Mass Index and Mortality in the General Population and in Subjects with Chronic Disease in Korea: A Nationwide Cohort Study (2002-2010)

BACKGROUND

The association between body mass index (BMI) and mortality is not conclusive, especially in East Asian populations. Furthermore, the association has been neither supported by recent data, nor assessed after controlling for weight changes.

METHODS

We evaluated the relationship between BMI and all-cause or cause-specific mortality, using prospective cohort data by the National Health Insurance Service in Korea, which consisted of more than one million subjects. A total of 153,484 Korean adults over 30 years of age without pre-existing cardiovascular disease or cancer at baseline were followed-up until 2010 (mean follow-up period = 7.91 ± 0.59 years). Study subjects repeatedly measured body weight 3.99 times, on average.

RESULTS

During follow-up, 3,937 total deaths occurred; 557 deaths from cardiovascular disease, and 1,224 from cancer. In multiple-adjusted analyses, U-shaped associations were found between BMI and mortality from any cause, cardiovascular disease, and cancer after adjustment for age, sex, smoking status, alcohol consumption, physical activity, socioeconomic status, and weight change. Subjects with a BMI < 23 kg/m2 and ≥ 30 kg/m2 had higher risks of all-cause and cause-specific mortality compared with the reference group (BMI 23-24.9 kg/m2). The lowest risk of all-cause mortality was observed in subjects with a BMI of 25-26.4 kg/m2 (adjusted hazard ratio [HR] 0.86; 95% CI 0.77 to 0.97). In subgroup analyses, including the elderly and those with chronic diseases (diabetes mellitus, hypertension, and chronic kidney disease), subjects with a BMI of 25-29.9 kg/m2 (moderate obesity) had a lower risk of mortality compared with the reference. However, this association has been attenuated in younger individuals, in those with higher socioeconomic status, and those without chronic diseases.

CONCLUSION

Moderate obesity was associated more strongly with a lower risk of mortality than with normal, underweight, and overweight groups in the general population of South Korea. This obesity paradox was prominent in not only the elderly but also individuals with chronic disease.

LECT2 induces atherosclerotic inflammatory reaction via CD209 receptor-mediated JNK phosphorylation in human endothelial cells

OBJECTIVE

Leukocyte cell-derived chemotaxin 2 (LECT2) is a recently discovered novel hepatokine, leading to skeletal muscle insulin resistance by activating c-Jun N-terminal kinase (JNK). However, its role in atherosclerotic inflammatory reactions has not been examined. Therefore, we investigated the function of LECT2 on the expression of vascular adhesion molecules and inflammatory cytokines in human endothelial cells.

METHODS

Human umbilical vein endothelial cells (HUVECs) and THP-1 cells were treated with various doses of LECT2 and the functions and signaling pathways were analyzed through Western blot and quantitative real-time PCR (qPCR).

RESULTS

The level of phosphorylated c-Jun N-terminal kinases (JNK) was significantly increased by LECT2 treatment in HUVECs and THP-1 cells, an effect that was not seen in cells treated with CD209 siRNA, a known LECT2 receptor. LECT2 treatment efficiently increased the expression of intercellular adhesion molecule-1 (ICAM-1) and pro-inflammatory cytokines tumor necrosis factor α (TNFα), monocyte chemo-attractant protein-1 (MCP-1), and interleukin-1β (IL-1β) in HUVECs and THP-1 cells. However, all these reactions were significantly reduced in response to treatment with JNK inhibitor. Furthermore, LECT2 treatment significantly exacerbated the adhesion of monocytic cells to human endothelial cells, which was also efficiently attenuated by JNK inhibitor.

CONCLUSIONS

LECT2 significantly induced adhesion molecules and pro-inflammatory cytokines in HUVECs via CD209-mediated JNK phosphorylation, suggesting that liver-derived novel hepatokine, LECT2, might directly mediate in the atherosclerotic inflammatory reactions in human endothelial cells.

BAIBA attenuates insulin resistance and inflammation induced by palmitate or a high fat diet via an AMPK-PPARδ-dependent pathway in mice

AIMS/HYPOTHESIS

We explored the effects of β-aminoisobutyric acid (BAIBA) on hyperlipidaemic-condition-induced insulin resistance and inflammation as mediated through a signalling pathway involving AMP-activated protein kinase (AMPK) and peroxisome proliferator-activated receptor δ (PPARδ).

METHODS

Mouse skeletal muscle C2C12 cells and C57BL/6J mice were treated with palmitate or a high-fat diet (HFD) and BAIBA. Inflammation and the expression of genes associated with insulin signalling were determined by western blot and quantitative real-time PCR. Selected genes from candidate pathways were evaluated by small interfering (si)RNA knockdown and specific inhibitors.

RESULTS

BAIBA treatment ameliorated impairment of insulin receptor substrate (IRS)-1/Akt-mediated insulin signalling in palmitate-treated C2C12 myocytes and in skeletal muscle of HFD-fed mice. In addition, BAIBA treatment reversed HFD-induced increases in body weight and improved impaired glucose tolerance in mice. In vitro and in vivo, inhibitory κBα (IκBα) phosphorylation, nuclear factor κB (NFκB) nuclear translocation and downstream inflammatory cytokines were significantly suppressed by BAIBA. Furthermore, BAIBA treatment significantly induced AMPK phosphorylation and expression of PPARδ in C2C12 myocytes and in skeletal muscle of mice. Both compound C, an AMPK inhibitor, and Pparδ (also known as Ppard) siRNA abrogated the inhibitory effects of BAIBA on palmitate-induced inflammation and insulin resistance. BAIBA significantly induced the expression of genes associated with fatty acid oxidation, such as carnitine palmitoyltransferase 1 (Cpt1), acyl-CoA oxidase (Aco; also known as Acox1) and fatty acid binding protein 3 (Fabp3); this effect of BAIBA was significantly reduced by compound C and Pparδ siRNA.

CONCLUSIONS/INTERPRETATION

These results are the first to demonstrate that BAIBA attenuates insulin resistance, suppresses inflammation and induces fatty acid oxidation via the AMPK-PPARδ pathway in skeletal muscle.

Implications of Pericardial, Visceral and Subcutaneous Adipose Tissue on Vascular Inflammation Measured Using 18FDG-PET/CT

Objective

Pericardial adipose tissue (PAT) is associated with adverse cardiometabolic risk factors and cardiovascular disease (CVD). However, the relative implications of PAT, abdominal visceral and subcutaneous adipose tissue on vascular inflammation have not been explored.

Method and Results

We compared the association of PAT, abdominal visceral fat area (VFA), and subcutaneous fat area (SFA) with vascular inflammation, represented as the target-to-background ratio (TBR), the blood-normalized standardized uptake value measured using ¹⁸F-Fluorodeoxyglucose Positron Emission Tomography (¹⁸FDG-PET) in 93 men and women without diabetes or CVD. Age- and sex-adjusted correlation analysis showed that PAT, VFA, and SFA were positively associated with most cardiometabolic risk factors, including systolic blood pressure, LDL-cholesterol, triglycerides, glucose, insulin resistance and high sensitive C-reactive proteins (hsCRP), whereas they were negatively associated with HDL-cholesterol. In particular, the maximum TBR (maxTBR) values were positively correlated with PAT and VFA (r = 0.48 and r = 0.45, respectively; both P <0.001), whereas SFA showed a relatively weak positive relationship with maxTBR level (r = 0.31, P = 0.003).

Conclusion

This study demonstrated that both PAT and VFA are significantly and similarly associated with vascular inflammation and various cardiometabolic risk profiles.

Analysis of comedone, sebum and porphyrin on the face and body for comedogenicity assay

BACKGROUND/PURPOSE

Many ingredients used in cosmetics evoke a comedogenic response. Rabbit ear model (REM) is a useful method that can replace human in examining materials and products in early developmental stage. However, a number of studies pointed out its disadvantage that it overreacts to comedogenic materials. The purpose of this study was to find the most appropriate region for evaluating comedogenicity in human skin.

METHODS

Sixty-six female subjects (age 32.48 ± 10 years; range 20-52 years) with mild to moderate facial acne lesions were included in this study. The whole face, upper chest, and back of volunteers were photographed. Lesion (closed and open comedones) counting, instrumentation of sebum secretion level, and analysis of porphyrin number were performed. The entire study was performed under environmental conditions of specific relative temperature and humidity, controlled and maintained identically for each volunteer.

RESULTS

In case of closed comedone, forehead showed a significant correlation with frontal cheek, lateral cheek, chin, and upper back. Meanwhile, significant correlations were observed between frontal cheek and chin as well as lateral cheek and chest. As for open comedone, forehead showed a significant correlation with chin site. A significant correlation was also observed between front cheek and lateral cheek as well as between upper chest and back. Analyzing the correlation between the occurrence of comedones and sebum in each region, a significant correlation between closed comedone and sebum was observed in frontal and lateral cheek. Analyzing the correlation between the occurrence of comedones and porphyrine in each region, a significant correlation between open comedone and porphyrin was observed in chin.

CONCLUSION

When evaluating the comedogenicity of cosmetics ingredients or products, this study recommends using both of the methods of testing on back and directly testing on face according to the characteristics of the materials. In case of mild potent ingredients or products in particular, verification through usability test that the directly test on face will help securing reliability.

The dipeptidyl peptidase-IV inhibitor inhibits the expression of vascular adhesion molecules and inflammatory cytokines in HUVECs via Akt- and AMPK-dependent mechanisms

Recently, dipeptidyl peptidase-IV (DPP-IV) inhibitor, a major anti-hyperglycemic agent, has received substantial attention as a possible therapeutic target for inflammatory diseases such as atherosclerosis. However, the direct molecular mechanisms through which DPP-IV inhibitor mediates anti-inflammatory effects in vascular endothelial cells have not been clarified. The effects of the DPP-IV inhibitor, gemigliptin, were analyzed in human umbilical vein endothelial cells (HUVECs) and THP-1 cells. Using Western blotting, we demonstrated that gemigliptin efficiently increased the level of AMP-activated protein kinase (AMPK) and Akt phosphorylation in a dose-dependent manner. The levels of lipopolysaccharide (LPS)-mediated phosphorylated nuclear factor-κB (NF-κB) and c-Jun N-terminal kinase (JNK) were significantly decreased after gemigliptin treatment. Furthermore, gemigliptin reduced LPS-induced expression of adhesion molecules and inflammatory cytokines such as vascular cell adhesion molecule-1 (VCAM-1), E-selectin, tumor necrosis factor-α (TNF-α), monocyte chemoattractant protein-1 (MCP-1), interleukin-1β (IL-1β), and IL-6 in HUVECs. In macrophage-like THP-1 cells, gemigliptin effectively inhibited LPS- and low-density lipoprotein (LDL)-induced foam cell formation. However, these anti-inflammatory and anti-atherosclerotic effects of gemigliptin in HUVECs and THP-1 cells were significantly reduced after treatment with an AMPK or an Akt inhibitor. Our results suggest that gemigliptin efficiently inhibited LPS-induced pro-inflammatory effects in vascular endothelial cells by attenuating NF-κB and JNK signaling via Akt/AMPK-dependent mechanisms. Therefore, the DPP-IV inhibitor, gemigliptin, may directly protect the vascular endothelium against inflammatory diseases such as atherosclerosis.

Evening chronotype is associated with metabolic disorders and body composition in middle-aged adults

CONTEXT

Chronotype is a trait determining individual circadian preference in behavioral and biological rhythm relative to external light-dark cycle. However, little is known about the relationship between chronotype and metabolic disorders.

OBJECTIVE

The aim of this study was to examine whether late chronotype is related to metabolic abnormalities and body composition in middle-aged adults, independent of sleep duration and lifestyle.

DESIGN AND PARTICIPANTS

A total of 1620 participants aged 47-59 years were recruited from the Korean Genome and Epidemiology Study.

MAIN OUTCOME MEASURES

Chronotype was assessed by the Morningness-Eveningness Questionnaire. Associations of chronotype with diabetes, metabolic syndrome, sarcopenia, and visceral obesity were analyzed. All participants underwent the oral glucose tolerance test, and body composition was measured with dual energy x-ray absorptiometry. Visceral obesity was designated as visceral fat area, measured by abdominal computed tomography, of >100 cm(2).

RESULTS

Chronotype was classified as morning in 29.6% of subjects, evening in 5.9%, neither morning nor evening in 64.5%. Evening type, when compared with morning type, was significantly associated with diabetes (odds ratio [OR], 1.73; 95% confidence interval [CI], 1.01-2.95), metabolic syndrome (OR, 1.74; 95% CI, 1.05-2.87), and sarcopenia (OR, 3.16; 95% CI, 1.36-7.33) after adjusting for confounding factors. Gender differences in the associations were evident. In men, evening type was associated with diabetes (OR, 2.98; 95% CI, 1.39-6.39) and sarcopenia (OR, 3.89; 95% CI, 1.33-11.33). Only metabolic syndrome was associated with evening type in women (OR, 2.22; 95% CI, 1.11-4.43).

CONCLUSIONS

At the population level, evening chronotype was independently associated with diabetes, metabolic syndrome, and sarcopenia. These results support the importance of circadian rhythms in metabolic regulation.

Association between body size phenotype and sleep duration: Korean National Health and Nutrition Examination Survey V (KNHANES V)

OBJECTIVE

Recent studies reported the presence of unique subsets of body size phenotypes that are more susceptible or more resistant to the development of obesity-associated metabolic disorders, although the underlying mechanism is not yet fully elucidated. We investigated the association between body size phenotypes and sleep duration after adjusting potential confounding factors.

MATERIALS AND METHODS

We analyzed data from the Korean National Health and Nutrition Examination Survey V (KNHANES V), a nation-wide, population-based health survey including 9077 Korean adults. The average amount of sleep per night was categorized as: ≤6, 7, 8, and ≥9 h. Body size phenotypes were classified based on body mass index (BMI) and presence of metabolic syndrome; metabolically healthy and normal weight (MHNW), metabolically abnormal but normal weight (MANW), metabolically healthy but obese (MHO), and metabolically abnormal obese (MAO).

RESULTS

According to sleep duration, there were significant differences in age, gender, BMI, waist circumference, and blood pressure (all P <0.05). Multivariate analysis showed that obese groups (MHO and MAO) had significantly shorter sleep durations than non-obese groups (MHNW and MANW) (6.78±0.04 vs. 6.93±0.03, P <0.001). Sleep duration was significantly different according to body size phenotype, irrespective of confounding factors, such as age, gender, smoking status, alcohol consumption, physical activity, income, and education (MHO; 6.73±0.05, MAO; 6.82±0.05, MHNW; 6.94±0.04, and MANW; 6.91±0.05; P <0.001).

CONCLUSION

Sleep duration is independently associated with body size phenotype after adjusting for confounding factors in the Korean population.