OBJECTIVE To investigate the triglyceride-glucose (TyG) index association with coronary artery calcification (CAC) progression in adult Koreans. RESEARCH DESIGN AND METHODS Various cardiovascular risk factors and anthropometric profiles were assessed in 1,175 subjects who previously had a CAC evaluation at least twice by multidetector computed tomography in a health care center. The TyG index was determined using ln(fasting triglycerides [mg/dL] × fasting glucose [mg/dL]/2). The CAC progression was defined as either incident CAC in a CAC-free population at baseline or an increase of ≥2.5 units between the square roots of the baseline and follow-up coronary artery calcium scores (CACSs) of subjects with detectable CAC at baseline. RESULTS CAC progression was seen in 312 subjects (27%) during 4.2 years follow-up. On the basis of the TyG index, subjects were stratified into three groups. Follow-up CACS and incidence of CAC progression were markedly elevated with rising TyG index tertile. Logistic regression analysis adjusted for various risk factors revealed an odds ratio for CAC progression of 1.82 (95% CI 1.20–2.77; P ≤ 0.01) when the highest and lowest TyG index tertiles were compared. CONCLUSIONS The TyG index is an independent predictor of CAC progression.

The triglyceride glucose (TyG) index has been suggested as a simple surrogate marker of insulin resistance. However, there are limited data regarding the association between the TyG index and arterial stiffness in adults. Therefore, we evaluated the relationship between the TyG index and arterial stiffness as measured based on brachial ankle pulse wave velocity (baPWV) in Korean adults. A total of 3587 subjects were enrolled in this study. Anthropometric and cardiovascular risk factors were measured. The TyG index was calculated as ln[fasting triglycerides(mg/dl) × fasting glucose(mg/dl)/2], and the insulin resistance index of homeostasis model assessment (HOMA-IR) was estimated. Arterial stiffness was determined by measuring baPWV. The subjects were stratified into four groups based on the TyG index. There were significant differences in cardiovascular parameters among the groups; the mean baPWV increased significantly with increasing TyG index. According to the logistic regression analysis after adjusting for multiple risk factors, the odds ratio (95% CI) for increased baPWV (> 75th percentile) for the highest and lowest quartiles of the TyG index was 2.92 (1.92–4.44) in men and 1.84 (1.15–2.96) in women, and the odds ratio for increased baPWV for the highest and lowest quartiles of the HOMA-IR was 1.80 (1.17–2.78) in men and 1.46 (1.06–2.47) in women, respectively. The TyG index is more independently associated with increased arterial stiffness than HOMA-IR in Korean adults.

The triglyceride glucose (TyG) index has been considered a simple surrogate marker of insulin resistance. However, few studies have investigated the relationship between the TyG index and coronary artery calcification (CAC). Thus, we investigated the relationship between the TyG index and CAC in healthy Korean adults. In total, 4319 participants who underwent cardiac computed tomography (CT) in a health promotion center were enrolled. Anthropometric profiles and multiple cardiovascular risk factors were measured. The TyG index was calculated as ln [fasting triglycerides (mg/dL) × fasting glucose (mg/dL)/2], and the insulin resistance index of homeostasis model assessment (HOMA-IR) was estimated. The CAC was measured using multidetector CT, and CAC presence was defined as an Agatston score of >0. All subjects were stratified into four groups based on their TyG indices. Significant differences were observed in cardiovascular parameters among the groups, and the prevalence of CAC significantly increased with increasing TyG index. In the logistic regression analysis after adjustment for multiple risk factors, the odds ratio for the prevalence of CAC, when comparing the highest and lowest quartiles of the TyG index was 1.95 (95% CI 1.23–3.11; P for trend = 0.01); the odds ratio for the prevalence of CAC, when comparing the highest and lowest quartiles of HOMA-IR was 1.64 (95% CI 1.12–2.40; P for trend = 0.04). In the receiver operating characteristics analysis, the TyG index was superior to HOMA-IR in predicting CAC. The TyG index is more independently associated with the presence of coronary artery atherosclerosis than is HOMA-IR in healthy Korean adults.

Recently, the triglyceride glucose (TyG) index has been considered a surrogate marker of insulin resistance which is a well-known pathogenic factor in nonalcoholic fatty liver disease (NAFLD). However, few studies have investigated the relationship between the TyG index and NAFLD. Thus, we investigated the relationship between the TyG index and NAFLD and the effectiveness of the TyG index compared with the homeostasis model assessment of insulin resistance (HOMA-IR) in identifying NAFLD in Korean adults. Participants of 4,986 who underwent ultrasonography in a health promotion center were enrolled. The TyG index was calculated as ln [fasting triglycerides (mg/dL)×fasting glucose (mg/dL)/2], and HOMA-IR was estimated. NAFLD was diagnosed by ultrasonography. Significant differences were observed in metabolic parameters among the quartiles of the TyG index. The prevalence of NAFLD significantly increased with increment in the TyG index. After adjusting for multiple risk factors, a logistic regression analysis was performed. When the highest and lowest quartiles of the TyG index and HOMA-IR were compared, the odds ratios for the prevalence of NAFLD were 2.94 and 1.93 (95% confidence interval, 2.32 to 3.72 and 1.43 to 2.61; both P for trend <0.01), respectively. According to the receiver operating characteristic analysis, the TyG index was superior to HOMA-IR in predicting NAFLD. The TyG index and prevalence of NAFLD were significantly related and the TyG index was superior to HOMA-IR in predicting NAFLD in Korean adults.

Background: Metformin can cause serum vitamin B12 deficiency, but studies on the influence of its duration and dose are lacking. We investigated vitamin B12 deficiency in patients with type 2 diabetes using metformin, in conjunction with other related factors. Method: This cross-sectional study included 1111 patients with type 2 diabetes who took metformin for at least 6 months. Serum vitamin B12 levels were quantified using a competitive-binding immunoenzymatic assay, and vitamin B12 deficiency was defined as serum B12 <300 pg/mL. Information on metformin use and confounding variables were collected from records or questionnaires and interviews. Result: Serum vitamin B12 deficiency occurred in 22.2% of patients (n = 247). After adjusting for confounders, a 1 mg increase in daily metformin dose was associated with a 0.142 pg/mL decrease in vitamin B12 (P < .001). Compared with a daily dose of <1000 mg, the adjusted odds ratios for 1000 to 1500, 1500 to 2000, and ≥2000 mg metformin were 1.72 (P = .080), 3.34 (P < .001), and 8.67 (P < .001), respectively. Vitamin B12 deficiency occurred less often in patients taking multivitamins (odds ratio 0.23; P < .001). After adjusting for confounding factors, there was no correlation between B12 deficiency and duration of metformin use. Serum homocysteine levels showed significant negative correlation with vitamin B12. Conclusion: Metformin at ≥1500 mg/d could be a major factor related to vitamin B12 deficiency, whereas concurrent supplementation of multivitamins may potentially protect against the deficiency. Serum homocysteine levels were negatively correlated with vitamin B12 levels, suggesting that B12 deficiency due to metformin use may occur at the tissue level. However, this hypothesis will require further study.

Aims/Introduction: Natural killer (NK) cells are cytotoxic lymphocytes critical to human immunity. Previous studies showed correlations between NK cell function and blood glucose concentrations. The purpose of the present study was to assess the NK cell activity and various metabolic parameters in people with type 2 diabetes, prediabetes and normal glucose tolerance.Materials and Methods: A total of 49 participants were enrolled in the study. Anthropometric and biochemical parameters including age, sex, body mass index, smoking status, blood pressure, fasting plasma glucose, C‐peptide, insulin, glycated hemoglobin, total cholesterol, triglyceride, high‐density lipoprotein cholesterol and low‐density lipoprotein cholesterol were assessed. The 75 g oral glucose tolerance test was carried out for 2‐h postload glucose level. Homeostatic model assessment was calculated for insulin resistance and β‐cell function. NK cell activity was measured by detecting the circulating interferon‐gamma level secreted from NK cells.Results: NK cell activity was lower in patients with type 2 diabetes (768.01 ± 650.35) compared with those with prediabetes (2,396.08 ± 653.76, P < 0.001) and normal glucose tolerance (2,435.31 ± 633.22, P < 0.001). In patients with type 2 diabetes, there was a significant inverse linear relationship between NK cell activity and fasting plasma glucose, glycated hemoglobin, and 2‐h postload glucose level (all P < 0.001). Multiple regression analysis showed glycated hemoglobin to be an independent predictor of NK cell activity in patients with type 2 diabetes.Conclusions: Compared with individuals with normal glucose tolerance or prediabetes, type 2 diabetes patients have a reduced NK cell activity, and it is significantly related to glucose control.