Risk of type 2 diabetes mellitus (T2DM) is increased in metabolically obese but normal-weight people. However, we have limited knowledge of how to prevent T2DM in normal-weight people. We aimed to evaluate the association between triglyceride glucose (TyG) index and incident T2DM among normal-weight people in rural China. We included data from 5706 people with normal body mass index (BMI) (18.5–23.9 kg/m2) without baseline T2DM in a rural Chinese cohort followed for a median of 6.0 years. A Cox proportional-hazard model was used to assess the risk of incident T2DM by quartiles of TyG index and difference in TyG index between follow-up and baseline (TyG-D), estimating hazard ratios (HRs) and 95% confidence intervals (CIs). A generalized additive plot was used to show the nonparametric smoothed exposure–response association between risk of T2DM and TyG index as a continuous variable. TyG was calculated as ln [fasting triglyceride level (mg/dl) × fasting plasma glucose level (mg/dl)/2]. Risk of incident T2DM was increased with quartiles 2, 3 and 4 versus quartile 1 of TyG index (adjusted HR [aHR] 2.48 [95% CI 1.20–5.11], 3.77 [1.83–7.79], and 5.30 [2.21–12.71], P trend < 0.001 across quartiles of TyG index). Risk of incident T2DM was increased with quartile 4 versus quartile 1 of TyG-D (aHR 3.91 [2.22–6.87]). The results were consistent when analyses were restricted to participants without baseline metabolic syndrome and impaired fasting glucose level. The generalized additive plot showed cumulative increased risk of T2DM with increasing TyG index. Risk of incident T2DM is increased with increasing TyG index among rural Chinese people, so the index might be an important indicator for identifying people at high risk of T2DM.

Dairy products have been suggested to be related to the prevention of overweight or obesity, hypertension, and type 2 diabetes mellitus (T2DM). These associations are currently controversial, however, and a systematic quantitative meta-analysis is lacking. In this study, we examined the associations between dairy products and the risk of overweight or obesity, hypertension, and T2DM and tested for dose–response relations. We comprehensively searched PubMed, Embase, and Web of Science up to April 2021. Cohort studies were included if dairy food consumption was reported at a minimum of 3 levels or as continuous variables, and the associations were assessed with overweight or obesity, hypertension, and T2DM. Summary RRs and 95% CIs were estimated for the dose–response association. Restricted cubic splines were used to evaluate the linear or nonlinear relations. Among the 9887 articles retrieved, 42 articles were included. For overweight or obesity, a linear association was observed for total dairy, milk, and yogurt. The risk decreased by 25%, 7%, and 12% per 200-g/d increase for total dairy, high-fat dairy, and milk, respectively, and by 13% per 50-g/d increment of yogurt. For hypertension, a nonlinear association was observed with total dairy, whereas significant inverse associations were found for low-fat dairy (RR: 0.94; 95% CI: 0.90, 0.98) and milk (RR: 0.94; 95% CI: 0.92, 0.97) per 200-g/d intake increase. For T2DM, all types of dairy food consumption except for milk and low-fat dairy products showed nonlinear associations, with total dairy and yogurt intake associated with 3% and 7% lower risk per 200-g/d and 50-g/d intake increase, respectively. In conclusion, our study suggests that total dairy is associated with a low risk of overweight or obesity, hypertension, and T2DM, especially milk and yogurt for overweight or obesity, low-fat dairy and milk for hypertension, and yogurt for T2DM.

The objective of the present study was to summarize the prevalence and influencing factors of metabolically healthy obese (MHO) and metabolically obese but normal weight (MONW) among people≥18 years old in the general population worldwide. We searched for studies of the prevalence of MHO and MONW published in English and Chinese up to October 2013. Pooled prevalence estimates were calculated by a random-effects model according to a Q test. The effects of gender, region, age, sample size, smoking, and alcohol consumption on MHO and MONW were analyzed. Differences between subgroups were assessed by chi-square test. Publication bias was estimated by Egger’s test. Studies of MHO and MONW showed heterogeneity (I²=99.4% and I²=99.7%, respectively). The overall prevalence of MHO and MONW was 7.27% (95% CI 5.92–8.90%) and 19.98% (95% CI 16.54–23.94%), respectively. American populations had the highest MHO prevalence and European populations the highest MONW prevalence. Different patterns of MHO and MONW were observed in the subgroup analysis with respect to gender, age, sample size, smoking, alcohol consumption, and metabolically healthy criteria. The prevalence of both MHO and MONW were affected by gender, region, age, sample size, smoking, alcohol consumption, and metabolically healthy criteria, but studies showed high heterogeneity. ^* B. Wang and R. Zhuang contributed equally to this work.

Background: The evidence of the association between Chinese visceral adiposity index (CVAI) and risk of type 2 diabetes mellitus (T2DM) is limited. We explored the association of CVAI with T2DM and directly compared with the predictive power of CVAI with other visceral obesity indices (visceral adiposity index, waist to height ratio, waist circumference and body mass index) based on a large prospective study.Methods: We conducted a population‐based study of 12 237 Chinese participants. Cox proportional‐hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for the association between CVAI and T2DM.Results: During follow‐up (median: 6.01 years), the incidence of T2DM was 3.29, 7.34, 12.37 and 23.72 per 1000 person‐years for quartiles 1, 2, 3 and 4 of CVAI, respectively. The risk of T2DM was increased with quartiles 2, 3 and 4 vs quartile 1 of CVAI (HR 2.12 [95% CI 1.50‐3.00], 2.94 [2.10‐4.13] and 5.01 [3.57‐7.04], P_trend < 0.001). Per‐SD increase in CVAI was associated with a 72% increased risk of T2DM (HR 1.72 [95% CI 1.56‐1.88]). Sensitivity analyses did not alter the association. The area under receiver operating characteristic curve was significantly higher for CVAI than other visceral obesity indices (all P <.001). Similar results were observed in stratified analyses by sex.Conclusions: Our findings show a positive association between CVAI and risk of T2DM. CVAI has the best performance in predicting incident T2DM, so the index might be a reliable and applicable indicator identifying people at high risk of T2DM.