Multi-ancestry genome-wide association study of gestational diabetes mellitus highlights genetic links with type 2 diabetes

Gestational diabetes mellitus (GDM) is associated with increased risk of pregnancy complications and adverse perinatal outcomes. GDM often reoccurs and is associated with increased risk of subsequent diagnosis of type 2 diabetes (T2D). To improve our understanding of the aetiological factors and molecular processes driving the occurrence of GDM, including the extent to which these overlap with T2D pathophysiology, the GENetics of Diabetes In Pregnancy Consortium assembled genome-wide association studies of diverse ancestry in a total of 5485 women with GDM and 347 856 without GDM. Through multi-ancestry meta-analysis, we identified five loci with genome-wide significant association (P < 5 × 10-8) with GDM, mapping to/near MTNR1B (P = 4.3 × 10-54), TCF7L2 (P = 4.0 × 10-16), CDKAL1 (P = 1.6 × 10-14), CDKN2A-CDKN2B (P = 4.1 × 10-9) and HKDC1 (P = 2.9 × 10-8). Multiple lines of evidence pointed to the shared pathophysiology of GDM and T2D: (i) four of the five GDM loci (not HKDC1) have been previously reported at genome-wide significance for T2D; (ii) significant enrichment for associations with GDM at previously reported T2D loci; (iii) strong genetic correlation between GDM and T2D and (iv) enrichment of GDM associations mapping to genomic annotations in diabetes-relevant tissues and transcription factor binding sites. Mendelian randomization analyses demonstrated significant causal association (5% false discovery rate) of higher body mass index on increased GDM risk. Our results provide support for the hypothesis that GDM and T2D are part of the same underlying pathology but that, as exemplified by the HKDC1 locus, there are genetic determinants of GDM that are specific to glucose regulation in pregnancy.

The Anti-Atherosclerosis Effect of Anakinra, a Recombinant Human Interleukin-1 Receptor Antagonist, in Apolipoprotein E Knockout Mice

Interleukin (IL)-1β plays an important role in atherosclerosis pathogenesis. We aimed to investigate the effect of anakinra, a recombinant human IL-1 receptor antagonist, on the progression of atherosclerosis in apolipoprotein E knockout (ApoE−/−) mice. ApoE−/− mice (8-week male) were treated with saline (control), anakinra 10, 25, and 50 mg/kg, respectively (n = 10 in each group). Mice were fed a standard chow (4 weeks) followed by an atherogenic diet (35kcal% fat, 1.25% cholesterol, 12 weeks). Atheromatous plaques in ApoE−/− mice and the expression of inflammatory genes and signaling pathways in human umbilical vein endothelial cells (HUVECs), rat aortic smooth muscle cells (RAOSMCs), and 3T3-L1 adipocytes were assessed. Anakinra reduced the plaque size of the aortic arch (30.6% and 25.2% at the 25 mg/kg and 50 mg/kg doses, both p < 0.05) and serum triglyceride in ApoE−/− mice and suppressed inflammatory genes (IL-1β and IL-6) expressions in HUVECs and RAOSMCs (all p < 0.05). In RAOSMCs, anakinra reduced metalloproteinase-9 expression in a dose-dependent manner and inhibited cell migration. Anakinra-treated mice exhibited trends of lower CD68+ macrophage infiltration in visceral fat and monocyte chemoattractant protein-1 expression was reduced in 3T3-L1 adipocytes. Anakinra could be a useful component for complementary treatment with a standard regimen to reduce the residual cardiovascular risk.

Sequencing Cell-free Fetal DNA in Pregnant Women With GCK-MODY

CONTEXT

Individuals with monogenic diabetes due to inactivating glucokinase (GCK) variants typically do not require treatment, except potentially during pregnancy. In pregnancy, fetal GCK genotype determines whether treatment is indicated, but noninvasive methods are not clinically available.

OBJECTIVE

This work aims to develop a method to determine fetal GCK genotype noninvasively using maternal cell-free fetal DNA.

METHODS

This was a proof-of-concept study involving 3 pregnant women with a causal GCK variant that used information from 1) massive parallel sequencing of maternal plasma cell-free DNA, 2) direct haplotype sequences of maternal genomic DNA, and 3) the paternal genotypes to estimate relative haplotype dosage of the pathogenic variant-linked haplotype. Statistical testing of variant inheritance was performed using a sequential probability ratio test (SPRT).

RESULTS

In each of the 3 cases, plasma cell-free DNA was extracted once between gestational weeks 24 and 36. The fetal fraction of cell-free DNA ranged from 21.8% to 23.0%. Paternal homozygous alleles that were identical to the maternal GCK variant-linked allele were not overrepresented in the cell-free DNA. Paternal homozygous alleles that were identical to the maternal wild-type-linked allele were significantly overrepresented. Based on the SPRT, we predicted that all 3 cases did not inherit the GCK variant. Postnatal infant genotyping confirmed our prediction in each case.

CONCLUSION

We have successfully implemented a noninvasive method to predict fetal GCK genotype using cell-free DNA in 3 pregnant women carrying an inactivating GCK variant. This method could guide tailoring of hyperglycemia treatment in pregnancies of women with GCK monogenic diabetes.

Retinol-binding protein-4 was associated with sensitization to inhalant allergens in the elderly population

BACKGROUND/AIMS

Recent evidence suggests an association between allergic sensitization and metabolic markers. However, this association has rarely been examined in the elderly. Retinol-binding protein-4 (RBP-4) is a recently identified adipokine that acts on the muscle and liver affecting insulin sensitivity. We evaluated the association between metabolic parameters and allergic sensitization in the elderly.

METHODS

We analysed the database of the Korean Longitudinal Study on Health and Aging cohort study conducted during 2005 to 2006. Atopy was identified by inhalant allergen skin prick test. Metabolic conditions were assessed using anthropometric indices and serum biomarkers such as fasting glucose, lipid, adiponectin, and RBP-4.

RESULTS

Among the 854 elderly subjects, 17.2% had atopy. Plasma RBP-4 levels were significantly higher in the atopic elderly than nonatopic elderly (p = 0.003). When RBP-4 percentiles were categorized as under three groups, the prevalence of atopy and current rhinitis increased significantly with percentiles of RBP-4 levels (p = 0.019 and p = 0.007, respectively). Log RBP-4 was associated with atopy (odds ratio [OR], 4.10; p = 0.009) and current rhinitis (OR, 2.73; p = 0.014), but not with current asthma (OR, 1.17; p = 0.824). Higher RBP-4 level in atopic elderly was also observed in current rhinitis patients. Atopy, but not current rhinitis, showed significant relationships with log RBP-4 levels in multivariate analyses adjusted for other metabolic markers including body mass index.

CONCLUSION

RBP-4 positively associated with atopy in the general elderly population irrespective of other metabolic markers.

A subset of microRNAs in the Dlk1-Dio3 cluster regulates age-associated muscle atrophy by targeting Atrogin-1

BACKGROUND

The microRNAs (miRNAs) down-regulated in aged mouse skeletal muscle were mainly clustered within the delta-like homologue 1 and the type III iodothyronine deiodinase (Dlk1-Dio3) genomic region. Although clustered miRNAs are coexpressed and regulate multiple targets in a specific signalling pathway, the function of miRNAs in the Dlk1-Dio3 cluster in muscle aging is largely unknown. We aimed to ascertain whether these miRNAs play a common role to regulate age-related muscle atrophy.

METHODS

To examine anti-atrophic effect of miRNAs, we individually transfected 42 miRNA mimics in fully differentiated myotubes and analysed their diameters. The luciferase reporter assay using target 3' untranslated region (UTR) and RNA pull-down assay were employed to ascertain the target predicted by the TargetScan algorithm. To investigate the therapeutic potential of the miRNAs in vivo, we generated adeno-associated virus (AAV) serotype 9 expressing green fluorescent protein (GFP) (AAV9-GFP) bearing miR-376c-3p and infected it into the tibialis anterior muscle of old mice. We performed morphometric analysis and measured ex vivo isometric force using a force transducer. Human gluteus maximus muscle tissues (ages ranging from 25 to 80 years) were used to investigate expression levels of the conserved miRNAs in the Dlk1-Dio3 cluster.

RESULTS

We found that the majority of miRNAs (33 out of 42 tested) in the cluster induced anti-atrophic phenotypes in fully differentiated myotubes with increasing their diameters. Eighteen of these miRNAs, eight of which are conserved in humans, harboured predicted binding sites in the 3' UTR of muscle atrophy gene-1 (Atrogin-1) encoding a muscle-specific E3 ligase. Direct interactions were identified between these miRNAs and the 3' UTR of Atrogin-1, leading to repression of Atrogin-1 and thereby induction of eIF3f protein content, in both human and mouse skeletal muscle cells. Intramuscular delivery of AAV9 expressing miR-376c-3p, one of the most effective miRNAs in myotube thickening, dramatically ameliorated skeletal muscle atrophy and improved muscle function, including isometric force, twitch force, and fatigue resistance in old mice. Consistent with our findings in mice, the expression of miRNAs in the cluster was significantly down-regulated in human muscle from individuals > 50 years old.

CONCLUSIONS

Our study suggests that genetic intervention using a muscle-directed miRNA delivery system has therapeutic efficacy in preventing Atrogin-1-mediated muscle atrophy in sarcopenia.

A Randomized Trial Evaluating the Efficacy and Safety of Fast-Acting Insulin Aspart Compared With Insulin Aspart, Both in Combination With Insulin Degludec With or Without Metformin, in Adults With Type 2 Diabetes (ONSET 9)

OBJECTIVE

To evaluate the efficacy and safety of fast-acting insulin aspart (faster aspart) compared with insulin aspart (IAsp), both with insulin degludec with or without metformin, in adults with type 2 diabetes not optimally controlled with a basal-bolus regimen.

RESEARCH DESIGN AND METHODS

This multicenter, double-blind, treat-to-target trial randomized participants to faster aspart (n = 546) or IAsp (n = 545). All available information, regardless of treatment discontinuation or use of ancillary treatment, was used for evaluation of effect.

RESULTS

Noninferiority for the change from baseline in HbA_1c 16 weeks after randomization (primary end point) was confirmed for faster aspart versus IAsp (estimated treatment difference [ETD] -0.04% [95% CI -0.11; 0.03]; -0.39 mmol/mol [-1.15; 0.37]; P < 0.001). Faster aspart was superior to IAsp for change from baseline in 1-h postprandial glucose (PPG) increment using a meal test (ETD -0.40 mmol/L [-0.66; -0.14]; -7.23 mg/dL [-11.92; -2.55]; P = 0.001 for superiority). Change from baseline in self-measured 1-h PPG increment for the mean over all meals favored faster aspart (ETD -0.25 mmol/L [-0.42; -0.09]); -4.58 mg/dL [-7.59; -1.57]; P = 0.003). The overall rate of treatment-emergent severe or blood glucose (BG)-confirmed hypoglycemia was statistically significantly lower for faster aspart versus IAsp (estimated treatment ratio 0.81 [95% CI 0.68; 0.97]).

CONCLUSIONS

In combination with insulin degludec, faster aspart provided effective overall glycemic control, superior PPG control, and a lower rate of severe or BG-confirmed hypoglycemia versus IAsp in adults with type 2 diabetes not optimally controlled with a basal-bolus regimen.

COVID-19 and older people in Asia: Asian Working Group for Sarcopenia calls to actions

The coronavirus disease 2019 (COVID-19) pandemic has casted a huge impact on global public health and the economy. In this challenging situation, older people are vulnerable to the infection and the secondary effects of the pandemic and need special attention. To evaluate the impacts of COVID-19 on older people, it is important to balance the successful pandemic control and active management of secondary consequences. These considerations are particularly salient in the Asian context, with its diversity among countries in terms of sociocultural heritage, healthcare setup and availability of resources. Thus, the Asian Working Group for Sarcopenia summarized the considerations of Asian countries focusing on responses and difficulties in each country, impacts of health inequity related to the COVID-19 pandemic and proposed recommendations for older people, which are germane to the Asian context. More innovative services should be developed to address the increasing demands for new approaches to deliver healthcare in these difficult times and to establish resilient healthcare systems for older people. Geriatr Gerontol Int 2020; 9999: n/a-n/a.

Estimated Association Between Cytokines and the Progression to Diabetes: 10-year Follow-Up From a Community-Based Cohort

CONTEXT

The long-term association between multiple cytokines and progression to diabetes is still uncertain.

OBJECTIVE

To identify which cytokines could predict progression to prediabetes and type 2 diabetes over 10 years.

METHODS

The study included 912 participants aged 40 to 69 years at baseline from the Ansung cohort, part of the Korea Genome Epidemiology Study. At baseline, a 75-g oral glucose tolerance test and 8 cytokines were measured: plasminogen activator inhibitor 1 (PAI-1), resistin, interleukin 6, leptin, monocyte chemoattractant protein 1, tumor necrosis factor alpha, retinol binding protein 4 (RBP4), and adiponectin. People with normal glucose tolerance (NGT, n = 241) and prediabetes (n = 330) were followed-up biennially for 10 years. Multinomial logistic regression analysis was used to evaluate the predictability of cytokines on the new-onset prediabetes and type 2 diabetes.

RESULTS

At 10 years, 38 (15.8%) and 82 (34.0%) of those with NGT had converted to prediabetes and type 2 diabetes, respectively. Of those with prediabetes, 228 (69.1%) had converted to type 2 diabetes. In people with NGT or prediabetes at baseline, the highest tertile of RBP4 was associated with a 5.48-fold and 2.43-fold higher risk of progression to type 2 diabetes, respectively. The odds for converting from NGT to prediabetes in the highest tertile of PAI-1 and the lowest tertile of adiponectin were 3.23 and 3.37, respectively. In people with prediabetes at baseline, those in the highest tertile of resistin were 2.94 time more likely to develop type 2 diabetes (all P < 0.05).

CONCLUSIONS

In this 10-year prospective study, NGT with higher serum RBP4 and PAI-1, and with lower adiponectin were associated with new-onset prediabetes and type 2 diabetes.

Pregnancy Outcomes of Women Additionally Diagnosed as Gestational Diabetes by the International Association of the Diabetes and Pregnancy Study Groups Criteria

BACKGROUND

We investigated the pregnancy outcomes in women who were diagnosed with gestational diabetes mellitus (GDM) by the International Association of the Diabetes and Pregnancy Study Groups (IADPSG) criteria but not by the Carpenter-Coustan (CC) criteria.

METHODS

A total of 8,735 Korean pregnant women were identified at two hospitals between 2014 and 2016. Among them, 2,038 women participated in the prospective cohort to investigate pregnancy outcomes. Diagnosis of GDM was made via two-step approach with 50-g glucose challenge test for screening followed by diagnostic 2-hour 75-g oral glucose tolerance test. Women were divided into three groups: non-GDM, GDM diagnosed exclusively by the IADPSG criteria, and GDM diagnosed by the CC criteria.

RESULTS

The incidence of GDM was 2.1% according to the CC criteria, and 4.1% by the IADPSG criteria. Women diagnosed with GDM by the IADPSG criteria had a higher body mass index (22.0±3.1 kg/m² vs. 21.0±2.8 kg/m², P<0.001) and an increased risk of preeclampsia (odds ratio [OR], 6.90; 95% confidence interval [CI], 1.84 to 25.87; P=0.004) compared to non-GDM women. Compared to neonates of the non-GDM group, those of the IADPSG GDM group had an increased risk of being large for gestational age (OR, 2.39; 95% CI, 1.50 to 3.81; P<0.001), macrosomia (OR, 2.53; 95% CI, 1.26 to 5.10; P=0.009), and neonatal hypoglycemia (OR, 3.84; 95% CI, 1.01 to 14.74; P=0.049); they were also at an increased risk of requiring phototherapy (OR, 1.57; 95% CI, 1.07 to 2.31; P=0.022) compared to the non-GDM group.

CONCLUSION

The IADPSG criteria increased the incidence of GDM by nearly three-fold, and women diagnosed with GDM by the IADPSG criteria had an increased risk of adverse pregnancy outcomes in Korea.

Progression to Gestational Diabetes Mellitus in Pregnant Women with One Abnormal Value in Repeated Oral Glucose Tolerance Tests

BACKGROUND

Women with one abnormal value (OAV) in a 100 g oral glucose tolerance test (OGTT) during pregnancy are reported to have an increased risk of adverse pregnancy outcomes. However, there is limited data about whether women with OAV will progress to gestational diabetes mellitus (GDM) when the OGTT is repeated.

METHODS

To identify clinical and metabolic predictors for GDM in women with OAV, we conducted a retrospective study and identified women with OAV in the OGTT done at 24 to 30 weeks gestational age (GA) and repeated the second OGTT between 32 and 34 weeks of GA.

RESULTS

Among 137 women with OAV in the initial OGTT, 58 (42.3%) had normal, 40 (29.2%) had OAV and 39 (28.5%) had GDM in the second OGTT. Maternal age, prepregnancy body mass index, weight gain from prepregnancy to the second OGTT, GA at the time of the OGTT, and parity were similar among normal, OAV, and GDM groups. Plasma glucose levels in screening tests were different (151.8±15.7, 155.8±14.6, 162.5±20.3 mg/dL, P<0.05), but fasting, 1-, 2-, and 3-hour glucose levels in the initial OGTT were not. Compared to women with screen negative, women with untreated OAV had a higher frequency of macrosomia.

CONCLUSION

We demonstrated that women with OAV in the initial OGTT significantly progressed to GDM in the second OGTT. Clinical parameters predicting progression to GDM were not found. Repeating the OGTT in women with OAV in the initial test may be helpful to detect GDM progression.

Oral Glucose Tolerance Testing Allows Better Prediction of Diabetes in Women with a History of Gestational Diabetes Mellitus

BACKGROUND

We aimed to identify the postpartum metabolic factors that were associated with the development of diabetes in women with a history of gestational diabetes mellitus (GDM). In addition, we examined the role of the oral glucose tolerance test (OGTT) in the prediction of future diabetes.

METHODS

We conducted a prospective study of 179 subjects who previously had GDM but did not have diabetes at 2 months postpartum. The initial postpartum examination including a 75-g OGTT and the frequently sampled intravenous glucose tolerance test (FSIVGTT) was performed 12 months after delivery, and annual follow-up visits were made thereafter.

RESULTS

The insulinogenic index (IGI30) obtained from the OGTT was significantly correlated with the acute insulin response to glucose (AIRg) obtained from the FSIVGTT. The disposition indices obtained from the OGTT and FSIVGTT were also significantly correlated. Women who progressed to diabetes had a lower insulin secretory capacity including IGI30, AIRg, and disposition indices obtained from the FSIVGTT and OGTT compared with those who did not. However, the insulin sensitivity indices obtained from the OGTT and FSIVGTT did not differ between the two groups. Multivariate logistic regression analysis showed that the 2-hour glucose and disposition index obtained from the FSIVGTT were significant postpartum metabolic risk factors for the development of diabetes.

CONCLUSION

We identified a crucial role of β-cell dysfunction in the development of diabetes in Korean women with previous GDM. The 2-hour glucose result from the OGTT is an independent predictor of future diabetes. Therefore, the OGTT is crucial for better prediction of future diabetes in Korean women with previous GDM.

Moderate hearing loss is related with social frailty in a community-dwelling older adults: The Korean Frailty and Aging Cohort Study (KFACS)

OBJECTIVES

To determine whether hearing loss is associated with social frailty in older adults.

METHODS

Cross-sectional analysis of cohort study data. Hearing was measured using of Pure-tone audiometry. Hearing loss was determined based on the average of hearing thresholds at 0.5, 1, and 2 kHz in the ear that had better hearing. Social frailty was defined based on the summation of the following 5 social components (1. Neighborhood meeting attendance 2. Talking to friend(s) sometimes 3.Someone gives you love and affection 4. Living alone 5. Meeting someone every day). Participants who had no correspondence to the components were considered non-social frailty; those with 1-2 components were considered social prefrailty; and those having 3 or more components were considered social frailty.

RESULTS

The prevalence of non-social frailty, social prefrailty, social frailty was 27.6%, 60.7% and 11.7% respectively. Of the five questions, two components (Neighborhood meeting attendance and Presence of someone who shows love and affection to the participants) were associated with hearing loss (p < 0.001). Compared to non-social frailty, the odds ratio of social frailty for hearing loss was 2.24 (95% CI 1.48-3.38) after adjusting for age, residential area, economic status, smoking, depressive disorder and MMSE, and 2.17 (95% CI 1.43-3.30) after further adjustments with physical frailty.

CONCLUSION

Hearing loss was associated with social frailty even after controlling confounding factors even including physical frailty.

Identifying Pathogenic Variants of Monogenic Diabetes Using Targeted Panel Sequencing in an East Asian Population

PURPOSE

Monogenic diabetes is a specific type of diabetes in which precision medicine could be applied. In this study, we used targeted panel sequencing to investigate pathogenic variants in Korean patients clinically suspected to have monogenic diabetes.

METHODS

The eligibility criteria for inclusion were non-type 1 diabetes patients with an age of onset ≤ 30 years and a BMI (body mass index) ≤ 30 kg/m2. Among the 2,090 non-type 1 diabetes patients, 109 were suspected to have monogenic diabetes and subjected to genetic testing. We analyzed 30 monogenic diabetes genes using targeted panel sequencing. The pathogenicity of the genetic variants was evaluated according to the American College of Medical Genetics and Genomics and the Association for Molecular Pathology guidelines.

RESULTS

Among the 109 suspected monogenic diabetes patients, 23 (21.1%) patients harbored pathogenic/likely pathogenic variants. A total of 14 pathogenic/likely pathogenic variants of common maturity onset diabetes of the young (MODY) genes were identified in GCK, HNF1A, HNF4A, and HNF1B. Other pathogenic/likely pathogenic variants were identified in WFS1, INS, ABCC8 and FOXP3. The mitochondrial DNA 3243 A>G variant was identified in five participants. Patients with pathogenic/likely pathogenic variants had a significantly higher MODY probability, a lower BMI, and a lower C-peptide level than those without pathogenic/likely pathogenic variants (P=0.007, P=0.001, and P=0.012, respectively).

CONCLUSIONS

Using targeted panel sequencing followed by pathogenicity evaluation, we were able to make molecular genetic diagnoses for 23 (21.1%) suspected monogenic diabetes patients. Lower BMI, higher MODY probability, and lower C-peptide levels were characteristics of these participants.

Comparison of pancreatic volume and fat amount linked with glucose homeostasis between healthy Caucasians and Koreans

AIM

To compare pancreatic volume and fat amount, and their associations with glucose homeostasis, in a Korean and a white population.

MATERIALS AND METHODS

In 43 healthy Korean and 43 healthy white people, matched for age (±3 years) and body mass index (BMI; ±1 kg/m² ), we measured pancreatic volume and fat amount in the pancreas and abdomen using computed tomography. Pancreatic β-cell function and insulin resistance were estimated according to biochemical characteristics and a 75-g oral glucose tolerance test. Body composition and resting energy expenditure (REE) were examined using bioimpedance and indirect calorimetry, respectively.

RESULTS

The mean ±SD age of the participants was 29.9 ± 5.9 years and 30.0 ± 5.2 years, and BMI was 24.0 ±3.7 and 24.1 ±3.2 kg/m² in the white participants and the Korean participants, respectively. Pancreatic volume in the white participants was greater than that in Korean participants (77.8 ±11.6 vs 68.2 ±12.1 cm³ ; P < .001). Pancreatic fat content in Korean participants was 22.8% higher than in white participants (P = .051). Insulinogenic index, disposition index, muscle mass and REE were significantly lower in Korean participants. Pancreatic volume was positively associated with indices linked to β-cell function; fat content in the pancreas was negatively associated with such indices, and positively with insulin resistance after adjusting for relevant variables including REE.

CONCLUSIONS

A smaller pancreas and higher fat deposition might be crucial determinants of vulnerability to diabetes in Korean people compared with white people with similar BMI and body fat levels.

Nonsynonymous Variants in PAX4 and GLP1R Are Associated With Type 2 Diabetes in an East Asian Population

We investigated ethnicity-specific exonic variants of type 2 diabetes (T2D) and its related clinical phenotypes in an East Asian population. We performed whole-exome sequencing in 917 T2D case and control subjects, and the findings were validated by exome array genotyping in 3,026 participants. In silico replication was conducted for seven nonsynonymous variants in an additional 13,122 participants. Single-variant and gene-based association tests for T2D were analyzed. A total of 728,838 variants were identified by whole-exome sequencing. Among nonsynonymous variants, PAX4 Arg192His increased risk of T2D and GLP1R Arg131Gln decreased risk of T2D in genome-wide significance (odds ratio [OR] 1.48, P = 4.47 × 10^-16 and OR 0.84, P = 3.55 × 10^-8, respectively). Another variant at PAX4 192 codon Arg192Ser was nominally associated with T2D (OR 1.62, P = 5.18 × 10^-4). In T2D patients, PAX4 Arg192His was associated with earlier age at diagnosis, and GLP1R Arg131Gln was associated with decreased risk of cardiovascular disease. In control subjects without diabetes, the PAX4 Arg192His was associated with higher fasting glucose and GLP1R Arg131Gln was associated with lower fasting glucose and HbA_1c level. Gene-based analysis revealed that SLC30A8 was most significantly associated with decreased risk of T2D (P = 1.0 × 10^-4). In summary, we have identified nonsynonymous variants associated with risk of T2D and related phenotypes in Koreans.

EuroQol Visual Analogue Scale (EQ-VAS) as a Predicting Tool for Frailty in Older Korean Adults: The Korean Frailty an Aging Cohort Study (KFACS)

OBJECTIVES

This study was conducted to determine the cutoff value and efficacy of the EuroQol Visual Analogue Scale (EQ-VAS) for predicting frailty.

DESIGN

The EQ-VAS medians (Interquartile Range) were compared and analyzed against the FFI.

PARTICIPANTS

The subjects were 1471 older adults aged 70 to 84 years who had completed both EQ-VAS and Fried Frailty index (FFI) in the first baseline year (2016) of the Korean Frailty and Aging Cohort Study.

RESULTS

Of the 1471 subjects,600 were classified as robust, 716 as pre-frail, and 155 as frail. The median EQ-VAS scores were 80.00 (20.00) for robust, 75.00 (25.00) for pre-frail, and 60.00 (25.00) for frail subjects.The medians of all five components of the FFI, weight loss (70.00 vs. 80.00), grip strength (70.00 vs. 80.00), exhaustion (70.00 vs. 80.00), walking velocity (70.00 vs. 80.00), and physical activity (70.00 vs. 80.00), were lower in the abnormal groups. We tested the efficacy of EQ-VAS as a diagnostic tool to predict frailty, and the area under the curve of EQ-VAS was 0.71 withthe optimal cut-off value of 72.

CONCLUSION

EQ-VAS presented negative correlation with FFI, and the optimal cut off value for frailty was 72. These results suggest that EQ-VAS is a valuable tool for assessing frailty andmay be a good predictor of frailty in Korean elderly population.

Rosiglitazone increases endothelial cell migration and vascular permeability through Akt phosphorylation

Background

Thiazolidinediones (TZDs), peroxisome proliferator-activated receptor-γ (PPAR-γ) agonists, exhibit anti-inflammatory and antioxidant properties and inhibit endothelial inflammation and dysfunction, which is anti-atherogenic. However, fluid retention, which may lead to congestive heart failure and peripheral edema, is also a concern, which may result from endothelial cell leakage. In the current study, we examined the effects of PPAR-γ agonists on vascular endothelial cell migration and permeability in order to determine its underlying mechanisms.

Methods

We used rosiglitazone and conducted cell migration assay and permeability assay using HUVEC cells and measured vascular permeability and leakage in male C57BL/6 mice.

Results

Rosiglitazone significantly promoted endothelial cell migration and induced permeability via activation of phosphatidylinositol-3-kinase (PI3K) – Akt or protein kinase C (PKC)β. In addition, rosiglitazone increased vascular endothelial growth factor (VEGF) expression and suppressed expression of tight junction proteins (JAM-A and ZO-1), which might promote neovascularization and vascular leakage. These phenomena were reduced by Akt inhibition.

Conclusions

Vascular endothelial cell migration and permeability change through Akt phosphorylation might be a mechanism of induced fluid retention and peripheral tissue edema by TZD.

Carbohydrate Composition Associated with the 2-Year Incidence of Metabolic Syndrome in Korean Adults

The aim of this study was to investigate the association between macronutrient composition and metabolic syndrome (MetS) incidence in Korean adults. Data were obtained from a cohort of 10,030 members aged 40 to 69 years who were enrolled from the 2 cities (Ansung and Ansan) between 2001 and 2002 to participate in the Korean Genome Epidemiology Study. Of these members, 5,565 participants, who were free of MetS and reported no diagnosis of cardiovascular disease at baseline, were included in this study. MetS was defined using the criteria of the National Cholesterol Education Program-Adult Treatment Panel III and Asia-Pacific criteria for waist circumference. MetS incidence rate were identified during a 2-year follow-up period. Baseline dietary information was obtained using a semi-quantitative food frequency questionnaire. Multivariate logistic regression analysis was used to evaluate the association between the quartiles of percentages of total calorie from macronutrients consumed and MetS incidence. In analyses, baseline information, including age, sex, body mass index, income status, educational status, smoking status, alcohol drinking status, and physical activity level was considered as confounding variables. Participants with the second quartile of the percentages of carbohydrate calorie (67%–70%) had a 23% reduced odds ratio (95% confidence interval, 0.61–0.97) for MetS incidence compared with those with the fourth quartile after adjusting for confounding variables. The findings suggest that middle aged or elderly Korean adults who consume approximately 67%–70% of calorie from carbohydrate have a reduced risk of MetS.

Prevention of type 2 diabetes mellitus in women with previous gestational diabetes mellitus

Gestational diabetes mellitus (GDM), defined as any degree of glucose intolerance with onset or first recognition during pregnancy, is characterized by underlying maternal defects in the β-cell response to insulin during pregnancy. Women with a previous history of GDM have a greater than 7-fold higher risk of developing postpartum diabetes compared with women without GDM. Various risk factors for postpartum diabetes have been identified, including maternal age, glucose levels in pregnancy, family history of diabetes, pre-pregnancy and postpartum body mass index, dietary patterns, physical activity, and breastfeeding. Genetic studies revealed that GDM shares common genetic variants with type 2 diabetes. A number of lifestyle interventional trials that aimed to ameliorate modifiable risk factors, including diet, exercise, and breastfeeding, succeeded in reducing the incidence of postpartum diabetes, weight retention, and other obesity-related morbidities. The present review summarizes the findings of previous studies on the incidence and risk factors of postpartum diabetes and discusses recent lifestyle interventional trials that attempted to prevent postpartum diabetes.

Vildagliptin reduces plasma stromal cell-derived factor-1α in patients with type 2 diabetes compared with glimepiride

AIMS/INTRODUCTION

Dipeptidyl peptidase-4 inhibitors might have pleiotropic protective effects on cardiovascular disease (CVD), in contrast to sulfonylureas. Therefore, we compared various CVD risk factors between vildagliptin and glimepiride.

MATERIALS AND METHODS

We carried out a randomized, prospective and crossover trial. A total of 16 patients with type 2 diabetes whose glycated hemoglobin was >7% were randomized to add vildagliptin or glimepiride. After 12-week treatment, each drug was replaced with the other for another 12 weeks. Before and after each treatment, glucose homeostasis and CVD risk factors were assessed, and the continuous glucose monitoring system was applied to calculate glycemic variability.

RESULTS

The mean age of the participants was 60 years, 31% were men, body mass index 25.5 kg/m² and HbA1c 8.41%. Both vildagliptin and glimepiride significantly decreased glycated hemoglobin and glycemic variability indices. Despite the improved glucose homeostasis, favorable change of CVD markers was not prominent in both the arms, along with significant weight gain. Only plasma stromal cell-derived factor (SDF)-1α decreased by 30% in the vildagliptin arm. According to regression analyses, the reduction of SDF-1α was independently associated with vildagliptin usage and serum interleukin-6 changes, but white blood cells were not related with the SDF-1α changes.

CONCLUSION

Compared with glimepiride, vildagliptin arrestingly decreased plasma SDF-1α, and its clinical implications should be further investigated.

Rg3 Improves Mitochondrial Function and the Expression of Key Genes Involved in Mitochondrial Biogenesis in C2C12 Myotubes

BACKGROUND

Panax ginseng has glucose-lowering effects, some of which are associated with the improvement in insulin resistance in skeletal muscle. Because mitochondria play a pivotal role in the insulin resistance of skeletal muscle, we investigated the effects of the ginsenoside Rg3, one of the active components of P. ginseng, on mitochondrial function and biogenesis in C2C12 myotubes.

METHODS

C2C12 myotubes were treated with Rg3 for 24 hours. Insulin signaling pathway proteins were examined by Western blot. Cellular adenosine triphosphate (ATP) levels and the oxygen consumption rate were measured. The protein or mRNA levels of mitochondrial complexes were evaluated by Western blot and quantitative reverse transcription polymerase chain reaction analysis.

RESULTS

Rg3 treatment to C2C12 cells activated the insulin signaling pathway proteins, insulin receptor substrate-1 and Akt. Rg3 increased ATP production and the oxygen consumption rate, suggesting improved mitochondrial function. Rg3 increased the expression of peroxisome proliferator-activated receptor γ coactivator 1α, nuclear respiratory factor 1, and mitochondrial transcription factor, which are transcription factors related to mitochondrial biogenesis. Subsequent increased expression of mitochondrial complex IV and V was also observed.

CONCLUSION

Our results suggest that Rg3 improves mitochondrial function and the expression of key genes involved in mitochondrial biogenesis, leading to an improvement in insulin resistance in skeletal muscle. Rg3 may have the potential to be developed as an anti-hyperglycemic agent.

Metabolic syndrome independently predicts future diabetes in women with a history of gestational diabetes mellitus

Metabolic syndrome (MetS) is an established predisposing condition for type 2 diabetes mellitus (T2DM). However, it is not thoroughly evaluated whether MetS increases the risk of T2DM in women with a previous history of gestational diabetes mellitus (GDM) who already at high risk of T2DM compared with the general population. We investigated the impact of MetS on the development of postpartum diabetes in women with a history of GDM.This was a multicenter, prospective cohort study of women diagnosed with GDM. The follow-up evaluations, including the oral glucose tolerance test, were completed at 6 weeks postpartum and annually thereafter. MetS was diagnosed at the initial postpartum evaluation according to the revised criteria of the National Cholesterol Education Program-Adult Treatment Panel III. The risk of developing type 2 diabetes (T2DM) in the follow-up period was analyzed based on the presence of MetS, and the adjusted risk was calculated using a Cox proportional hazards model.A total of 412 women without diabetes at the initial postpartum evaluation participated in the annual follow-up for median 3.8 years. MetS was prevalent in 66 (19.2%) women at the initial postpartum evaluation. The incidences of diabetes in women with and without MetS were 825 and 227 per 10,000 person-years, respectively (P < 0.001). The presence of MetS was an independent risk factor for T2DM, with a hazard ratio (HR) of 2.23 (95% confidence interval 1.04-5.08) in multivariate analysis after adjustment for clinical and metabolic parameters. When we considered MetS and impaired fasting glucose (IFG) separately, women with MetS, IFG, or both had an increased risk of T2DM, with HRs of 4.17, 4.36, and 6.98, respectively.The presence of MetS during the early postpartum period is an independent risk factor for the development of T2DM in women with a previous history of GDM.

Surveillance of the Middle East respiratory syndrome (MERS) coronavirus (CoV) infection in healthcare workers after contact with confirmed MERS patients: incidence and risk factors of MERS-CoV seropositivity

Given the mode of transmission of Middle East respiratory syndrome (MERS), healthcare workers (HCWs) in contact with MERS patients are expected to be at risk of MERS infections. We evaluated the prevalence of MERS coronavirus (CoV) immunoglobulin (Ig) G in HCWs exposed to MERS patients and calculated the incidence of MERS-affected cases in HCWs. We enrolled HCWs from hospitals where confirmed MERS patients had visited. Serum was collected 4 to 6 weeks after the last contact with a confirmed MERS patient. We performed an enzyme-linked immunosorbent assay (ELISA) to screen for the presence of MERS-CoV IgG and an indirect immunofluorescence test (IIFT) to confirm MERS-CoV IgG. We used a questionnaire to collect information regarding the exposure. We calculated the incidence of MERS-affected cases by dividing the sum of PCR-confirmed and serology-confirmed cases by the number of exposed HCWs in participating hospitals. In total, 1169 HCWs in 31 hospitals had contact with 114 MERS patients, and among the HCWs, 15 were PCR-confirmed MERS cases in study hospitals. Serologic analysis was performed for 737 participants. ELISA was positive in five participants and borderline for seven. IIFT was positive for two (0.3%) of these 12 participants. Among the participants who did not use appropriate personal protective equipment (PPE), seropositivity was 0.7% (2/294) compared to 0% (0/443) in cases with appropriate PPE use. The incidence of MERS infection in HCWs was 1.5% (17/1169). The seroprevalence of MERS-CoV IgG among HCWs was higher among participants who did not use appropriate PPE.

The effects of body mass index on the hereditary influences that determine peak bone mass in mother-daughter pairs (KNHANES V)

A daughter's bone mineral density (BMD) is significantly correlated with her mother's BMD, but the daughter's body mass index (BMI) could modulate this association. Maternal inheritance dominantly affects daughters with a lower BMI, but BMI could compensate for hereditary influences in daughters with a higher BMI in terms of daughter's BMD.

INTRODUCTION

Achieving optimal peak bone mass at a young age is the best way to protect against future osteoporosis and subsequent fractures. Although environmental components influence bone mass accrual, but peak bone mass is largely programmed by inheritance. The aims of this study were to investigate the influence of maternal inheritance on the daughter's bone mass and to assess whether these influences differ according to the daughter's body mass index (BMI).

METHODS

We used data obtained from the 2010 Korean National Health and Nutrition Examination Survey V and included 187 mother-daughter pairs. Bone mineral density (BMD) was measured at the lumbar spine (LS), femur neck (FN), and total hip (TH) by using dual-energy X-ray absorptiometry (DXA). The daughter group was stratified into two groups according to the mean BMI (21.4 kg/m(2)).

RESULTS

The daughters' BMD correlated significantly with both their BMI and their mothers' Z-score for each skeletal site. In the daughters with a lower BMI (≤21.4 kg/m(2)), the BMDs at the FN and TH were affected more by the mothers' Z-score than by the daughters' BMI. Meanwhile, the influence of the daughters' BMI on their BMD was higher than that of their mothers' Z-score in daughters with a higher BMI (>21.4 kg/m(2)). Moreover, the mothers' Z-scores were a significant predictor of their daughters having Z-scores < -1.0 only in daughters with a lower BMI.

CONCLUSIONS

This study suggests that maternal inheritance is an important determinant of the daughters' bone mass, but that this hereditary factor may vary according to the daughters' BMI.

Age- and sex-specific association of circulating osteocalcin with dynamic measures of glucose homeostasis

SUMMARY

Our study showed that serum osteocalcin levels are closely related to glucose metabolism in men of all ages and younger women. This association disappeared in postmenopausal women in which increases bone turnover rates. The association between serum osteocalcin levels and glucose homeostasis should be interpreted according to age and sex.

INTRODUCTION

Osteocalcin, a marker of bone formation, appears to be associated with glucose homeostasis. We investigated the age- and sex-specific association of serum osteocalcin level with variables related to glucose metabolism.

METHODS

This study was based on cross-sectional analysis from 719 participants aged 20-85 years after excluding patients taking antidiabetic or antiosteoporotic drugs. The subjects were divided into four groups according to age and sex as follows: men <50 years (n = 131), men ≥50 years (n = 191), women <50 years (n = 108), and women ≥50 years (n = 279). Anthropometric and biochemical variables including insulin resistance (HOMA-IR) and β cell function (HOMA-β) from a 75-g oral glucose tolerance test, and serum 25-OH-vitamin D and parathyroid hormone levels were measured.

RESULTS

The serum osteocalcin level was significantly higher in women aged ≥50 years compared with women <50 years (20.4 ± 7.8 vs. 17.9 ± 6.8 ng/ml, p < 0.001), but there was no difference between men aged ≥50 years and men <50 years (16.4 ± 5.9 vs. 16.8 ± 6.0 ng/ml, p = 0.905). The participants diagnosed with diabetes had lower serum osteocalcin levels than normal or prediabetic participants. Multivariable regression analyses including HOMA-IR and HOMA-β indicated that serum osteocalcin levels had a negative and independent association with HbA1c levels in men and women aged <50 years, but not in women ≥50 years.

CONCLUSIONS

Low osteocalcin levels are associated with impaired glucose metabolism in men and premenopausal women. The osteocalcin levels may be determined by factors related to bone metabolism in postmenopausal women. Our data suggest that the serum levels of osteocalcin associated with glucose homeostasis should be interpreted according to age and sex.

Sarcopenia as a Predictor of Future Cognitive Impairment in Older Adults

OBJECTIVES

We investigated the association between the indices of sarcopenia and future risk of cognitive impairment in older adults.

DESIGN

Community-based prospective cohort study.

SETTING

Community.

PARTICIPANTS

A total of 297 participants aged ≥65 years without cognitive impairment at baseline (mean age, 71.9 ± 6.6 years; men:women, 158:139) and who underwent cognitive evaluation at the 5-year follow-up.

MEASUREMENTS

Sarcopenia parameters including appendicular lean mass (ALM), handgrip strength, and the Short Physical Performance Battery (SPPB) score at baseline were compared according to the later progression of mild cognitive impairment (MCI) and/or dementia. The operational criteria suggested by the Foundation for the National Institutes of Health Sarcopenia Project were used. We performed multivariate logistic regression analysis to identify the independent indicators of the progression of cognitive impairment.

RESULTS

Among the 297 participants, 242 (81.5%) remained cognitively normal (nonprogression group), whereas 55 (18.5%) showed progression of cognitive impairment (50 subjects (16.8%) to MCI and 5 subjects (1.7%) to dementia) (progression group). Compared with the nonprogression group, subjects in the progression group were older, had a lower educational level, and had lower physical function as assessed by the SPPB; a higher percentage were depressed. Other baseline markers of sarcopenia, including the ALM-to-body mass index ratio and handgrip strength did not differ significantly between the groups. The association between a low SPPB score (<9) and progression of cognitive impairment was maintained after adjustment for conventional risk factors for cognitive impairment (hazard ratio 2.222, 95% confidence interval 1.047-4.716, P = 0.038).

CONCLUSION

Decreased physical performance, as assessed by the SPPB, but not other markers of sarcopenia, was independently associated with the risk of later cognitive impairment in older adults.

Favorable effect of dietary vitamin C on bone mineral density in postmenopausal women (KNHANES IV, 2009): discrepancies regarding skeletal sites, age, and vitamin D status

Dietary vitamin C intake showed significant positive associations with BMD in postmenopausal women, especially with vitamin D deficiency.

INTRODUCTION

Although there is a positive role of vitamin C in osteoblastogenesis, debate remains about the contribution of vitamin C to bone mineral density (BMD) in humans.

METHODS

Data were derived from the Fourth Korean National Health and Nutrition Examination Survey. Dietary information was assessed using a 24-h dietary recall questionnaire. BMD was measured by dual-energy X-ray absorptiometry at the lumbar and hip.

RESULTS

A total of 1,196 postmenopausal women aged 50 years and older were stratified into tertiles by daily dietary vitamin C intake. After adjusting for traditional confounders, dietary vitamin C intake tertile was significantly positively associated with BMD at all sites (R = 0.513 for lumbar spine (LS) and R = 0.657 for femoral neck (FN), P < 0.05 for each). The subjects with osteoporosis had significantly lower dietary vitamin C intake than did subjects without osteoporosis (74.4 ± 66.2 vs 94.1 ± 78.6 mg/day for LS and 65.5 ± 56.6 vs 94.3 ± 79.2 mg/day for FN, respectively, P < 0.001). The multiple-adjusted odds ratio for osteoporosis for dietary vitamin C <100 mg/day was 1.790 (95 % CI 1.333-2.405, P < 0.001). However, the significant association between vitamin C intake and BMD was only observed in subjects with vitamin D deficiency and aged 50-59 years or >70 years.

CONCLUSION

Dietary vitamin C intake was positively associated with BMD in postmenopausal women, and inadequate vitamin C intake could increase the risk of osteoporosis.

Weight Gain and Progression to Type 2 Diabetes in Women With a History of Gestational Diabetes Mellitus

CONTEXT

The effect of weight gain on the development of type 2 diabetes after gestational diabetes mellitus (GDM) is not fully understood in Asian women who have a relatively low body mass index (BMI).

OBJECTIVE

We investigated the effect of postpartum longitudinal BMI change on the development of diabetes in Korean women with a history of GDM.

DESIGN AND SETTING

The study included a hospital-based, multicenter, prospective cohort with median follow-up of 4.0 years.

PARTICIPANTS

A total of 418 women with previous GDM or gestational impaired glucose tolerance were recruited and underwent an oral glucose tolerance test at 6 weeks postpartum and annually thereafter.

MAIN OUTCOME MEASURE

The risk of diabetes was analyzed according to the tertiles of BMI change. Changes in BMI were calculated between the initial postpartum visit and the last follow-up or at the onset of diabetes.

RESULTS

The BMI change in each tertile was -1.8 ± 1.1, -0.2 ± 0.3, and 1.6 ± 1.2 kg/m(2), respectively. We observed an increased risk of incident diabetes as the tertile of BMI change increased (8.6%, 12.6%, and 16.9%, P = .039). Postpartum BMI change was an independent predictor of diabetes in a multivariate Cox analysis (hazard ratio 1.27, 95% confidence interval 1.04-1.56, P = .021), even after adjusting for BMI at the last follow-up. In the highest tertile group, there was a significant deterioration in cardiovascular risk factors including blood pressure, lipid profile, and insulin sensitivity.

CONCLUSIONS

Postpartum increase in BMI is significantly associated with a risk of diabetes and deterioration of metabolic phenotypes in Korean GDM women.

Serum 25-hydroxyvitamin D level and the risk of mild cognitive impairment and dementia: the Korean Longitudinal Study on Health and Aging (KLoSHA)

OBJECTIVE

The association of low vitamin D status with mild cognitive impairment (MCI), a preclinical condition that can lead to dementia, has not yet been fully explored. Our aim was to investigate the association between vitamin D status and the future risk of MCI and dementia in older adults.

DESIGN, SETTING AND PARTICIPANTS

We conducted a population-based prospective study as a part of the Korean Longitudinal Study on Health and Aging. Four hundred and twelve elderly participants who completed evaluations of cognitive function and metabolic parameters in 2005-2006 and 2010-2011 were analysed.

MAJOR OUTCOME MEASURE

The rate of development of MCI or dementia during the study period was compared according to baseline vitamin D status. Binary logistic regression analysis was performed to investigate any independent association between vitamin D status and the risks of MCI or dementia.

RESULTS

Among 405 subjects that remained after excluding seven demented subjects at baseline, 338 subjects remained unchanged or improved in their diagnosis for cognitive function during the study period, whereas 67 subjects showed progression to MCI or dementia. When analyzing 236 subjects whose baseline mini-mental state examination (MMSE) scores were <27, severe vitamin D deficiency at baseline, defined as <25 nmol/l, was independently associated with the progression of cognitive impairment. Among 297 subjects who were normal at baseline, 50 acquired MCI and 247 remained normal. Severe vitamin D deficiency was also independently associated with the development of MCI when analyzing 145 subjects whose baseline MMSE scores were <27.

CONCLUSION

Severe vitamin D deficiency was independently associated with the future risk of MCI as well as dementia, especially in older adults whose baseline MMSE scores had decreased only modestly.

Identification of novel autoantibodies in type 1 diabetic patients using a high-density protein microarray

Autoantibodies can facilitate diagnostic and therapeutic means for type 1 diabetes (T1DM). We profiled autoantibodies from serum samples of 16 T1DM patients, 16 type 2 diabetic (T2DM) patients, and 27 healthy control subjects with normal glucose tolerance (NGT) by using protein microarrays containing 9,480 proteins. Two novel autoantibodies, anti-EEF1A1 and anti-UBE2L3, were selected from microarrays followed by immunofluorescence staining of pancreas. We then tested the validity of the candidates by ELISA in two independent test cohorts: 1) 95 adults with T1DM, 49 with T2DM, 11 with latent autoimmune diabetes in adults (LADA), 20 with Graves disease, and 66 with NGT and 2) 33 children with T1DM and 34 healthy children. Concentrations of these autoantibodies were significantly higher in T1DM patients than in NGT and T2DM subjects (P < 0.01), which was also confirmed in the test cohort of children (P < 0.05). Prevalence of anti-EEF1A1 and anti-UBE2L3 antibodies was 29.5% and 35.8% in T1DM, respectively. Of note, 40.9% of T1DM patients who lack anti-GAD antibodies (GADA) had anti-EEF1A1 and/or anti-UBE2L3 antibodies. These were also detected in patients with fulminant T1DM but not LADA. Our approach identified autoantibodies that can provide a new dimension of information indicative of T1DM independent of GADA and new insights into diagnosis and classification of T1DM.

Effects of Dietary Fat Types on Growth Performance, Pork Quality, and Gene Expression in Growing-finishing Pigs

This study was performed to determine the effects of dietary fat sources, i.e., beef tallow, soybean oil, olive oil and coconut oil (each 3% in feed), on the growth performance, meat quality and gene expression in growing-finishing pigs. A total of 72 crossbred pigs (Landrace×Large White×Duroc) were used at 71±1 kg body weight (about 130 d of age) in 24 pens (320×150 cm) in a confined pig house (three pigs per pen) with six replicate pens per treatment. The growing diet was given for periods of 14±3 d and the finishing diet was given for periods of 28±3 d. The fat type had no significant effect either on growth performance or on chemical composition or on meat quality in growing-finishing pigs. Dietary fat type affected fatty acid composition, with higher levels of unsaturated fatty acids (UFAs) and monounsaturated fatty acids (MUFAs) in the olive oil group. Microarray analysis in the Longissimus dorsi identified 6 genes, related to insulin signaling pathway, that were differentially expressed among the different feed groups. Real time-PCR was conducted on the six genes in the longissimus dorsi muscle (LM). In particular, the genes encoding the protein kinase, cAMP-dependent, regulatory, type II, alpha (PRKAR2A) and the catalytic subunit of protein phosphatase 1, beta isoform (PPP1CB) showed the highest expression level in the olive oil group (respectively, p<0.05, p<0.001). The results of this study indicate that the type of dietary fat affects fatty acid composition and insulin signaling-related gene expression in the LM of pigs.

A genome-wide association study on thyroid function and anti-thyroid peroxidase antibodies in Koreans

Genetic factors are thought to be an important determinant of thyroid function and autoimmunity. However, there are limited data on genetic variants in Asians. In this study, we performed a genome-wide association study on plasma thyroid-stimulating hormone (TSH) and free thyroxine (fT4) concentration and anti-thyroid peroxidase (anti-TPO) antibody positivity in 4238 Korean subjects. In the Stage 1 genome scan, 3396 participants from the Ansung cohort were investigated using 1.42 million genotyped or imputed markers. In the Stage 2 follow-up, 10 markers were genotyped in 842 participants from the Korean Longitudinal Study on Health and Aging cohort. An intronic variant in VAV3, rs12126655, which has been reported in Europeans, was significantly associated with plasma TSH concentration in the joint Stages 1 and 2 analyses (P = 2.2 × 10(-8)). We observed that a novel variant, rs2071403, located 75 bp proximal to the translational start site of TPO was significantly associated with plasma anti-TPO antibody positivity in the joint Stages 1 and 2 analyses (P = 1.3 × 10(-10)). This variant had a marginal sex-specific effect, and its association was more significant in females. Subjects possessing the rs2071403A allele, associated with an absence of the anti-TPO antibody, had decreased TPO mRNA expression in their thyroid tissue. Another intronic variant of HLA-DPB2, rs733208, had a suggestive association with anti-TPO antibody positivity (P = 4.2 × 10(-7)). In conclusion, we have identified genetic variants that are strongly associated with TSH level and anti-TPO antibody positivity in Koreans. Further replications and meta-analysis are required to confirm these findings.

Serum FGF21 concentration is associated with hypertriglyceridaemia, hyperinsulinaemia and pericardial fat accumulation, independently of obesity, but not with current coronary artery status

OBJECTIVE

Fibroblast growth factor 21 (FGF21) is an emerging metabolic regulator associated with glucose and lipid metabolism. However, previous studies of FGF21 have been largely confounded by obesity, and data are limited for advanced outcomes such as coronary artery disease (CAD) and ectopic fat accumulation. We investigated the associations between serum FGF21 concentrations and glucose/lipid metabolism, CAD, and pericardial fat deposition in subjects strictly matched for obesity parameters.

DESIGN, PATIENTS AND MEASUREMENTS

We enrolled 189 patients who had undergone cardiac multidetector coronary computed tomography. We measured cardiometabolic parameters and serum FGF21 levels within body mass index (BMI)-matched groups. Correlations and linear regressions were analysed among serum FGF21 levels, pericardial fat volumes and cardiometabolic parameters. Serum FGF21 concentrations were compared in patients with and without diabetes, metabolic syndrome (MS) or CAD.

RESULTS

Serum FGF21 concentrations were significantly higher in BMI-matched patients with MS (107·2 ± 83·6 vs 82·1 ± 67·4 ng/l without MS, P < 0·05), but not among those with diabetes (84·3 ± 56·4 vs 96·3 ± 98·9 ng/l without diabetes, P = 0·300) or CAD (89·6 ± 65·8 vs 84·2 ± 83·1 ng/l without CAD, P = 0·633). Serum FGF21 concentrations correlated positively with triglycerides, low-density lipoprotein-cholesterol, insulin, HOMA-IR and pericardial fat volume. They showed an independent association with pericardial fat volume (β = 0·111 ± 0·053, P < 0·05).

CONCLUSIONS

Serum FGF21 concentrations were significantly associated with lipid profiles, insulin resistance, pericardial fat volume and MS, independently of obesity, but not with overt CAD or diabetes.

Optimal HbA1c cutoff for detecting diabetic retinopathy

The associations between high glucose levels and diabetic retinopathy have been the basis for the diagnosis of diabetes. We aimed to provide updated data on the relationship between HbA1c and diabetic retinopathy, and to assess the diagnostic accuracy of the proposed HbA1c cutoff for detecting diabetic retinopathy. This cross-sectional study included 3,403 adults from the 2009 to 2010 Ansung Cohort Study. Retinopathy was assessed with single-field nonmydriatic fundus photography and graded according to the International Clinical Diabetic Retinopathy Disease Severity Scale. HbA1c was measured by standardized assay using high performance liquid chromatography. Based on deciles distribution, the prevalence of retinopathy was very low until the HbA1c range of 48-51 mmol/mol (6.5-6.8 %). The optimal HbA1c cutoff for detecting any diabetic retinopathy was 49 mmol/mol (6.6 %), moderate or severer retinopathy was 52 mmol/mol (6.9 %) from receiver operating characteristic curve analysis. The proposed HbA1c threshold of 48 mmol/mol (6.5 %) from American Diabetes Association produced comparable accuracy for identifying both any and moderate/severer retinopathy. This study confirmed that the proposed HbA1c threshold of 48 mmol/mol (6.5 %) allowed the proper detection of diabetic retinopathy. Our data support the judicious use of HbA1c for the diagnosis of diabetes and detecting diabetic retinopathy as well.

Prediction of type 2 diabetes in women with a history of gestational diabetes using a genetic risk score

AIMS/HYPOTHESIS

Women with a history of gestational diabetes mellitus (GDM) are at increased risk of future development of type 2 diabetes. Recently, over 65 genetic variants have been confirmed to be associated with diabetes. We investigated whether this genetic information could improve the prediction of future diabetes in women with GDM.

METHODS

This was a prospective cohort study consisting of 395 women with GDM who were followed annually with an OGTT. A weighted genetic risk score (wGRS), consisting of 48 variants, was assessed for improving discrimination (C statistic) and risk reclassification (continuous net reclassification improvement [NRI] index) when added to clinical risk factors.

RESULTS

Among the 395 women with GDM, 116 (29.4%) developed diabetes during a median follow-up period of 45 months. Women with GDM who went on to develop diabetes had a significantly higher wGRS than those who did not (9.36 ± 0.92 vs 8.78 ± 1.07; p < 1.56 × 10(-7)). In a complex clinical model adjusted for age, prepregnancy BMI, family history of diabetes, blood pressure, fasting glucose and fasting insulin concentration, the C statistic marginally improved from 0.741 without the wGRS to 0.775 with the wGRS (p = 0.015). The addition of the wGRS to the clinical model resulted in a modest improvement in reclassification (continuous NRI 0.430 [95% CI 0.218, 0.642]; p = 7.0 × 10(-5)).

CONCLUSIONS/INTERPRETATION

In women with GDM, who are at high risk of diabetes, the wGRS was significantly associated with the future development of diabetes. Furthermore, it improved prediction over clinical risk factors.

Effect of seasonal changes on the transition between subclinical hypothyroid and euthyroid status

CONTEXT

The widespread use of thyroid tests in asymptomatic individuals identifies many patients with transient subclinical hypothyroidism.

OBJECTIVE

Our objective was to determine the effect of seasonal change on serum TSH levels and the transition between subclinical hypothyroid and euthyroid status.

DESIGN, SETTING, AND SUBJECTS

This was a retrospective longitudinal study of 1751 subclinical hypothyroid and 28 096 euthyroid subjects aged over 18 years who underwent serial thyroid function tests at a health screening center between October 2003 and May 2011.

MAIN OUTCOME MEASURES

Age-adjusted geometric mean values of the TSH level by month were calculated using linear mixed models. Adjusted odds ratios of test season and multiple baseline clinical factors were determined using generalized estimating equations.

RESULTS

During a median 36 months of follow-up, 57.9% of subclinical hypothyroid subjects reverted to euthyroidism, and 4.3% of euthyroid subjects developed subclinical hypothyroidism. The monthly distribution of follow-up TSH levels indicated a biphasic pattern, ie, an increase during the winter-spring season and a decrease during the summer-fall season, with a maximal TSH difference of 0.69 mIU/L in subclinical hypothyroid and 0.30 mIU/L in euthyroid subjects. Normalization of subclinical hypothyroidism was increased 1.4-fold in follow-up tests during the summer-fall follow-up, whereas subclinical hypothyroidism increased 1.4-fold in euthyroid subjects during the winter-spring follow-up.

CONCLUSIONS

The season in which thyroid testing was performed was independently related to the transition between subclinical hypothyroid and euthyroid status. Seasonal variations in TSH concentration should be considered before deciding on treatment of subclinical hypothyroidism, particularly in the areas with a wide annual temperature range.

Association of dietary quality indices with glycemic status in korean patients with type 2 diabetes

The present study was performed to evaluate the relationship between dietary quality indices including the Diet Quality Index-International (DQI-I), Alternate Healthy Eating Index (AHEI), and Healthy Diet Indicator (HDI) and glycemic status in Korean patients with type 2 diabetes. A total of 110 consecutive outpatients with type 2 diabetes who visited 2 university hospitals in Seoul and Seongnam from April 2004 to November 2006 were enrolled as subjects. At the time of enrollment, anthropometric parameters, dietary habits, experience of exercise, and metabolic parameters were obtained. Experienced registered dietitians collected one-day dietary intake using the 24-hour recall method. The mean scores for DQI-I, AHEI, and HDI were 68.9 ± 8.2, 39.4 ± 8.9, and 5.0 ± 1.3, respectively. After adjustment for age, body mass index, and energy intake, DQI-I and HDI were found to have a significant correlation with hemoglobin A1c (HbA1c) (r = -0.21, p < 0.05; r = -0.28, p < 0.05), fasting plasma glucose (r = -0.21, p < 0.05; r = -0.23, p < 0.05), and postprandial 2-h glucose (r = -0.30, p < 0.05; r = -0.26, p < 0.05, respectively). However, AHEI did not have a significant correlation with HbA1c. In conclusion, the DQI-I and HDI may be useful tools in assessing diet quality and adherence to dietary recommendations in Korean patients with type 2 diabetes. Future research is required to determine whether the dietary quality indices have predictive validity for dietary and glycemic changes following diet education in a clinical setting.

Efficacy and safety of the dipeptidyl peptidase-4 inhibitor gemigliptin compared with sitagliptin added to ongoing metformin therapy in patients with type 2 diabetes inadequately controlled with metformin alone

AIMS

This study was designed to assess the efficacy and safety of a dipeptidyl peptidase-4 inhibitor, gemigliptin versus sitagliptin added to metformin in patients with type 2 diabetes.

METHODS

We conducted a double-blind, randomized, active-controlled trial in 425 Asian patients with inadequately controlled type 2 diabetes being treated with metformin alone. Eligible patients were randomized into three groups: 50 mg gemigliptin qd, 25 mg gemigliptin bid or sitagliptin 100 mg qd added to ongoing metformin treatment for 24 weeks. Haemoglobin A1c (HbA1c) and fasting plasma glucose (FPG) were measured periodically, and oral glucose tolerance tests were performed at baseline and 24 weeks after starting the treatment regimen.

RESULTS

Twenty-four weeks later, adding gemigliptin (50 mg/day) to ongoing metformin therapy significantly improved glycaemic control. Reduction in HbA1c caused by 50 mg gemigliptin qd (-0.77% ± 0.8) was non-inferior to that caused by 100 mg sitagliptin qd (-0.8% ± 0.85). Proportion of patients achieving HbA1c <7% while taking 25 mg gemigliptin bid (50%) or 50 mg gemigliptin qd (54.07%) was comparable to the results with 100 mg sitagliptin qd (48.87%). There were significant decreases in FPG, postprandial glucose and AUC0-2 h glucose, as well as increases in GLP-1 and β cell sensitivity to glucose (supported by homeostasis model assessment of β-cell function, postprandial 2-h c-peptide and insulinogenic index) in patients receiving gemigliptin treatment with their metformin therapy. There was no increased risk of adverse effects with this dose of gemigliptin compared with sitagliptin 100 mg qd.

CONCLUSIONS

Addition of gemigliptin 50 mg daily to metformin was shown to be efficacious, well tolerated and non-inferior to sitagliptin in patients with type 2 diabetes mellitus.

Clinical and genetic risk factors for type 2 diabetes at early or late post partum after gestational diabetes mellitus

CONTEXT

Women with a history of gestational diabetes mellitus (GDM) are at increased risk of type 2 diabetes (T2DM). However, the time to progression to diabetes differs individually.

OBJECTIVE

We investigated the clinical and genetic risk factors that are associated with T2DM early or late post partum after GDM pregnancy.

DESIGN AND SETTING

This was a hospital-based prospective cohort study that enrolled GDM women.

PATIENTS AND OUTCOME MEASURES

A total of 843 GDM subjects were followed for the development of T2DM. Clinical risk factors were investigated during pregnancy, 2 months post partum, and annually thereafter. GDM subjects were genotyped for 21 known T2DM-associated genetic variants, and their genotype frequencies were compared with elderly nondiabetic controls.

RESULTS

At 2 months post partum, 105 (12.5%) subjects had T2DM (early converters). Among the 370 remaining subjects who underwent more than 1 year of follow-up, 88 (23.8%) had newly developed T2DM (late converters). Independent risk factors for early converters were higher prepregnancy body mass index, higher area under the curve of glucose during an antepartum oral glucose tolerance test, lower fasting insulin concentration, and decreased β-cell function. Independent risk factors for late converters were higher prepregnancy body mass index and higher glucose area under the curve. Variants in CDKN2A/2B and HHEX were associated with early conversion, whereas variants in CDKAL1 were associated with late conversion.

CONCLUSIONS

Obesity was a risk factor for both early and late T2DM converters. However, early converters had more pronounced defects in β-cell function, which might be explained, in part, by differences in genetic predisposition.

Efficacy and safety of glimepiride/metformin sustained release once daily vs. glimepiride/metformin twice daily in patients with type 2 diabetes

AIMS

The study investigated the clinical equivalence in reducing haemoglobin A1c (A1C) between glimepiride/metformin sustained release (GM-SR) 2/500 mg, a fixed-dose combination, once daily and glimepiride/metformin (GM) 1/250 mg, a fixed-dose combination, twice daily in patients with type 2 diabetes (T2D).

METHODS

A multicentre, randomised, double-blind, double-dummy study was conducted in 14 hospitals in Korea. Inclusion criteria were age 30-75 years, T2D diagnosis no longer than 10 years previously, A1C between 7% and 10%, and body mass index <40 kg/m(2) . A total of 207 subjects were randomised into the GM-SR group (n=101) or the GM group (n=106). Participants were assessed at baseline, 8 weeks and 16 weeks after treatment.

RESULTS

After 16 weeks treatment, no difference in baseline-adjusted changes of A1C (primary efficacy variable) was observed between the two groups (-0.59% for GM-SR group vs. -0.61% for GM group, 95% CI: -0.17 to 0.21; p=0.84). In addition, there were no significant differences in secondary efficacy parameters between the two groups, including changes in A1C up to week 8, changes in fasting plasma glucose (FPG) and 2-h-postprandial plasma glucose up to week 8 and week 16, response rate, drug compliance and hypoglycaemic events. However, there was a difference in baseline-adjusted changes of FPG between the two groups (-1.01 mmol/l for GM-SR group vs. -1.52 mmol/l for GM group, p=0.01 in the intention to treat set).

CONCLUSIONS

GM-SR 2/500 mg once daily was as effective as GM 1/250 mg twice daily in lowering A1C. In addition, no difference was noted in hypoglycaemic events between the two groups.

Plasma FGF21 levels are increased in patients with hypothyroidism independently of lipid profile

Thyroid hormone is a potent regulator of metabolic and energy homeostasis implicated in various metabolic diseases. Fibroblast growth factor 21(FGF21) is a systemic metabolic regulator known to modulate various biological functions similar to the actions of thyroid hormone. We investigated the differences in plasma FGF21 concentrations in patients with varying thyroid function. Ninety drug-naïve subjects who underwent thyroid evaluation at Seoul National University Bundang Hospital were enrolled and classified into euthyroid, subclinical hypothyroid, and overtly hypothyroid groups. Biochemical markers and plasma FGF21 levels were measured and analyzed. The mean age of the subjects was 42.6 ± 9.1 years. The mean body mass index (BMI), waist circumference, and fasting glucose concentrations were similar between groups. Overtly hypothyroid subjects exhibited significantly higher concentrations of total cholesterol, triglyceride, and LDL-cholesterol than the other groups (p<0.01). Mean plasma FGF21 concentrations in euthyroid, subclinical hypothyroid and overtly hypothyroid groups were 43.2 ± 39.2 pg/mL, 63.6 ± 73.6 pg/mL, and 101.5 ± 74.9 pg/mL, respectively (p<0.01 between groups). Plasma FGF21 concentrations remained significantly higher in overtly hypothyroid subjects after adjusting for serum triglyceride concentrations (p<0.005). Multivariate analysis revealed a significant positive linear relationship between serum TSH concentrations and plasma FGF21 concentrations (β = 0.192, p = 0.002) and a significant negative linear relationship between free T4 and plasma FGF21 concentrations (β = -0.382, p = 0.037) after adjusting for gender, BMI and serum concentrations of triglycerides and glucose. Plasma FGF21 levels were significantly increased in patients with hypothyroidism independently of BMI, or lipid or glucose metabolism.

Finding genetic risk factors of gestational diabetes

Gestational diabetes mellitus (GDM) is a complex metabolic disorder of pregnancy that is suspected to have a strong genetic predisposition. It is associated with poor perinatal outcome, and both GDM women and their offspring are at increased risk of future development of type 2 diabetes mellitus (T2DM). During the past several years, there has been progress in finding the genetic risk factors of GDM in relation to T2DM. Some of the genetic variants that were proven to be significantly associated with T2DM are also genetic risk factors of GDM. Recently, a genome-wide association study of GDM was performed and reported that genetic variants in CDKAL1 and MTNR1B were associated with GDM at a genome-wide significance level. Current investigations using next-generation sequencing will improve our insight into the pathophysiology of GDM. It would be important to know whether genetic information revealed from these studies could improve our prediction of GDM and the future development of T2DM. We hope further research on the genetics of GDM would ultimately lead us to personalized genomic medicine and improved patient care.

Genome-wide association study identifies GYS2 as a novel genetic factor for polycystic ovary syndrome through obesity-related condition

To investigate the role of genetic predisposition in the pathogenesis of polycystic ovary syndrome (PCOS) in relation to obesity, we performed a genome-wide association study of PCOS in Koreans (n=1741). PCOS is a heterogeneous endocrinal disorder of uncertain etiology. Obesity is one of the well-known risk factors for PCOS. Genome-wide association study. Women with or without PCOS. A total of 1881 samples were genotyped using Illumina HumanOmni1 Quad v1 and processed by R packages. The PCOS patients were divided into two subgroups according to PCOS diagnostic criteria (Rotterdam and National Institutes of Health (NIH)). For PCOS-associated loci in the two definitions, we successfully confirmed significant associations of GYS2 for body mass index in the discovery stage. We further replicated pleiotropic associations of GYS2 in a childhood obesity study (n=482) and in a gestational diabetes study (n=1710), respectively. Our study provides a preliminary framework upon diverse genetic effects underlying PCOS in Korean women. A newly identified GYS2 gene as a predisposing factor of PCOS might expand understanding of the biological pathways in metabolic and endocrine regulation.

Comparison between sitagliptin as add-on therapy to insulin and insulin dose-increase therapy in uncontrolled Korean type 2 diabetes: CSI study

AIM

Individuals requiring insulin therapy for type 2 diabetes often require escalation of their regimen to achieve glycaemic control. Optimal management strategies for uncontrolled type 2 diabetes would improve glycaemic control without hypoglycaemia and weight gain. This study compared the efficacy and tolerability of adding sitagliptin, an oral dipeptidyl peptidase-4 inhibitor, and an up to 20% increase in insulin dose in patients with uncontrolled type 2 diabetes on insulin therapy.

METHODS

We conducted a 24-week, randomized, active-competitor, parallel-group study in subjects with uncontrolled type 2 diabetes [haemoglobin A1c (HbA1c) = 7.5-11%] currently using insulin therapy. Subjects were randomly assigned to either the sitagliptin adding (100 mg daily, n = 70) or an insulin-increasing arm (≥ 10% at week 12 and ≥ 10% at week 24, n = 70) while continuing other medications.

RESULTS

Average baseline HbA1c was 9.2% in both groups. HbA1c decreased more at 24 weeks in the sitagliptin adding than the insulin-increasing arm (-0.6 ± 0.1% vs. -0.2 ± 0.1%, p < 0.01). Insulin was increased by 25% at 24 weeks in the insulin-increasing group. Hypoglycaemic events were less common and less severe in sitagliptin adding arm than insulin-increasing arm (7.0 vs. 14.3 events per patient-year, p < 0.05). Weight was stable in the sitagliptin adding subjects (68.6 ± 11.6 vs. 68.1 ± 11.4 kg) but increased in the insulin-increasing subjects (66.2 ± 10.6 vs. 67.4 ± 9.7 kg, p < 0.05). Other adverse events occurred at similar rates in both arms.

CONCLUSIONS

Compared to a 25% increase in insulin dose, adding sitagliptin to an insulin-based regimen was more effective at lowering HbA1c and associated with less hypoglycaemia and weight gain over 24 weeks.

CLINICAL TRIAL NUMBER

NCT01100125.

Bisphenol A impairs mitochondrial function in the liver at doses below the no observed adverse effect level

Bisphenol A (BPA) has been reported to possess hepatic toxicity. We investigated the hypothesis that BPA, below the no observed adverse effect level (NOAEL), can induce hepatic damage and mitochondrial dysfunction by increasing oxidative stress in the liver. Two doses of BPA, 0.05 and 1.2 mg/kg body weight/day, were administered intraperitoneally for 5 days to mice. Both treatments impaired the structure of the hepatic mitochondria, although oxygen consumption rate and expression of the respiratory complex decreased only at the higher dose. The hepatic levels of malondialdehyde (MDA), a naturally occurring product of lipid peroxidation, increased, while the expression of glutathione peroxidase 3 (GPx3) decreased, after BPA treatment. The expression levels of proinflammatory cytokines such as interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) also increased. In HepG2 cells, 10 or 100 nM of BPA also decreased the oxygen consumption rate, ATP production, and the mitochondrial membrane potential. In conclusion, doses of BPA below the NOAEL induce mitochondrial dysfunction in the liver, and this is associated with an increase in oxidative stress and inflammation.

A genome-wide association study of gestational diabetes mellitus in Korean women

Knowledge regarding the genetic risk loci for gestational diabetes mellitus (GDM) is still limited. In this study, we performed a two-stage genome-wide association analysis in Korean women. In the stage 1 genome scan, 468 women with GDM and 1,242 nondiabetic control women were compared using 2.19 million genotyped or imputed markers. We selected 11 loci for further genotyping in stage 2 samples of 931 case and 783 control subjects. The joint effect of stage 1 plus stage 2 studies was analyzed by meta-analysis. We also investigated the effect of known type 2 diabetes variants in GDM. Two loci known to be associated with type 2 diabetes had a genome-wide significant association with GDM in the joint analysis. rs7754840, a variant in CDKAL1, had the strongest association with GDM (odds ratio 1.518; P=6.65×10(-16)). A variant near MTNR1B, rs10830962, was also significantly associated with the risk of GDM (1.454; P=2.49×10(-13)). We found that there is an excess of association between known type 2 diabetes variants and GDM above what is expected under the null hypothesis. In conclusion, we have confirmed that genetic variants in CDKAL1 and near MTNR1B are strongly associated with GDM in Korean women. There seems to be a shared genetic basis between GDM and type 2 diabetes.

Association of variations in TPH1 and HTR2B with gestational weight gain and measures of obesity

Serotonin is involved in appetite regulation and energy homeostasis. Recently, it has been reported that 5-hydroxytryptamine receptor 2B (Htr2b) and tryptophan hydroxylase 1 (Tph1) play major role in β-cell proliferation in mouse during pregnancy. We investigated the genetic association of HTR2B and TPH1 with risk of gestational diabetes mellitus (GDM) and measures of obesity, in 869 Korean GDM women and carefully selected 632 nondiabetic control subjects. Six single-nucleotide polymorphisms (SNPs) in HTR2B and ten SNPs in TPH1 were selected for genotyping according to their tagging status. Genetic variants in HTR2B and TPH1 were not associated with the risk of GDM. In GDM women, SNPs of TPH1 were significantly associated with weight gain during pregnancy. In nondiabetic controls, SNPs of TPH1 were associated with waist circumference and BMI. We also found that a variant of TPH1 (rs623580) was associated with BMI in a genome-wide association study comprised of 8,842 subjects. Although genetic variants in HTR2B and TPH1 were not associated with risk of GDM, we found significant association of these variants with measures of obesity. However, further replication studies in a different population are required to confirm our findings.