Association of hypertriglyceridemic waist-to-height ratio and its dynamic status with risk of type 2 diabetes mellitus: The Rural Chinese Cohort Study.

AIMS: To evaluate the risk of type 2 diabetes mellitus (T2DM) in a prospective study with hypertriglyceridemic waist-to-height ratio (HWHtR) and its dynamic status. METHODS: We collected data for 12,248 participants ≥18 years in this study. Cox's proportional-hazards regression was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for T2DM risk by baseline HWHtR. Multiple logistic regression analysis was used to estimate odds ratios (ORs) and 95% CIs for T2DM risk by transformation in HWHtR. RESULTS: We identified 839 T2DM cases during a median follow-up of 5.92 years. Compared with normal TG level and normal WHtR, T2DM risk was increased with high TG level and high WHtR (aHR 2.04, 95% CI 1.49-2.79). Similar results were observed in subgroup analyses by sex and age. During follow-up, T2DM risk was increased with stable high TG level and high WHtR (aOR 4.45, 95% CI 2.76-7.17) compared with stable normal TG level and normal WHtR. The results above were robust in sensitivity analyses. CONCLUSIONS: HWHtR phenotype and its dynamic status were associated with risk of T2DM. Our study suggests that primary prevention and avoiding the appearance of the HWHtR phenotype in the rural Chinese population may reduce the T2DM risk.

Association of ABCG1 gene methylation and its dynamic change status with incident type 2 diabetes mellitus: the Rural Chinese Cohort Study.

To explore whether DNA methylation of the ATP-binding cassette G1 (ABCG1) gene and its dynamic change are associated with incident type 2 diabetes mellitus (T2DM). We conducted a nested case-control study with 286 pairs of T2DM cases and matched controls nested in the Rural Chinese Cohort Study. Conditional logistic regression models were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for incident T2DM risk according to ABCG1 methylation level at baseline and its dynamic change at follow-up examination. Spearman's rank correlation coefficients were used to analyze the association between ABCG1 methylation and its possible risk factors in the control group. We found that T2DM risk increased by 16% (OR = 1.16, 95% CI = 1.02-1.31) with each 1% increase in DNA methylation levels of the ABCG1 loci CpG13 and CpG14. DNA methylation change of the ABCG1 locus CpG15 during the 6-year follow-up was associated with increased T2DM risk: T2DM risk increased by 78% in the upper tertile group (methylation gain ≥5%) versus lower tertile group (methylation gain <1%) (OR = 1.78, 95% CI = 1.01-3.15). Furthermore, body mass index was positively correlated with the DNA methylation level of the ABCG1 loci CpG13, CpG14 and CpG15. In conclusion, DNA methylation levels of the ABCG1 loci CpG13 and CpG14 and the methylation gain of locus CpG15 were positively associated with incident T2DM risk, which may suggest a possible etiologic pattern for T2DM and potentially improve T2DM prediction in rural Chinese people.

Deaths from total and premature cardiovascular disease associated with high normal blood pressure and hypertension in rural Chinese men and elderly people.

To investigate the association of blood pressure (BP) categories with total and premature cardiovascular disease (CVD) mortality in rural Chinese. The study included 14,539 adults ≥18 years in rural China. Baseline study visits were conducted in 2007-2008, and follow-up visits in 2013-2014. Data were collected by face-to-face questionnaire interview, and anthropometric and laboratory measurements. A sub-distribution hazards model was used to calculate adjusted sub-distribution hazard ratios (aSHRs) and 95% confidence intervals (CIs). During the 6-year follow-up, 257 total and 209 premature CVD deaths occurred. As compared with normal BP (systolic BP/diastolic BP (SBP/DBP) < 120/80 mmHg), for men and people aged ≥60 years, hypertension (SBP/DBP ≥ 140/90 mmHg) associated with total CVD mortality (aSHR 3.57, 95% CI 2.06-6.17; aSHR 2.15, 1.29-3.56) and premature CVD mortality (aSHR 4.41, 2.37-8.21; aSHR 2.31, 1.27-4.19). Also, as compared with normal BP, for men and people aged ≥60 years with high normal BP (SBP/DBP 120-139/80-89 mmHg), risk of total CVD mortality increased (aSHR 1.85, 1.05-3.28; aSHR 1.78, 1.05-3.04), as was premature CVD mortality (aSHR 1.89, 0.99-3.64; aSHR 1.91, 1.03-3.54). Among men and people aged ≥60 years in rural China, risk of total and premature CVD mortality was increased for those with high normal BP and hypertension. Prevention and treatment strategies for additional CVD risk reduction targeting men and elderly people with hypertension or even high normal BP are needed to reduce CVD mortality risk.

Age and sex differences in the association between sleep duration and general and abdominal obesity at 6-year follow-up: the rural Chinese cohort study.

OBJECTIVE: The association between sleep duration and general and abdominal obesity in adults, especially in the rural Chinese population, remains unclear. Therefore, we conducted this study to evaluate the association between sleep duration and general and abdominal obesity in rural Chinese adults. METHODS: We included 12,446 adults aged 18-75 years old who completed a baseline examination during 2007-2008 and follow-up during 2013-2014. We prospectively investigated the sleep-obesity association over an average of six-year follow-up. Multivariable logistic regression was performed to assess the probability of new-onset general and abdominal obesity, estimating odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: As compared with sleep duration 6.5-7.5 h, short sleep duration (<6.5 h) was significantly associated with increased probability of abdominal obesity in men (OR = 1.60, 95% CI: 1.05-2.45) after controlling for multiple covariates. A similar association was found in men aged >60 years but not in women or in men ≤60 years. We found no significant association between sleep duration and general obesity. The results were consistent when restricting the analysis to participants without cardiovascular disease, type 2 diabetes mellitus or cancer at baseline. CONCLUSIONS: Short sleep duration was significantly associated with abdominal obesity in rural Chinese adults, and the association varied by sex and age.

TXNIP hypomethylation and its interaction with obesity and hypertriglyceridemia increase type 2 diabetes mellitus risk: A nested case-control study.

BACKGROUND: This study aims to estimate type 2 diabetes mellitus (T2DM) incidence with DNA methylation of the thioredoxin-interacting protein (TXNIP) gene and its interaction with environmental factors. MATERIALS AND METHODS: This case-control study included 286 incident T2DM cases and 286 non-T2DM controls matched by sex, age, marital status, race, and residence village nested in the Rural Chinese Cohort Study. A conditional logistic regression model was used to estimate the association of DNA methylation at TXNIP gene with T2DM risk. Also, multifactor dimensionality reduction (MDR) and classification and regression tree (CART) analyses were used to investigate the interaction between TXNIP methylation and environmental risk factors. RESULTS: Methylation levels of all five CpG loci at TXNIP gene were significantly lower in T2DM than in controls (all P < .001). With increasing methylation level, risk of T2DM was significantly decreased (odds ratio, 95% CI 0.80, 0.69-0.94 for CpG1; 0.80, 0.69-0.93 for CpG2; 0.70, 0.56-0.88 for CpG3; 0.78, 0.66-0.92 for CpG4; and 0.76, 0.60-0.97 for CpG5). Additionally, the essential interactions among TXNIP methylation, obesity, and hypertriglyceridemia were identified by CART and MDR analyses. On logistic regression analysis, the risk of T2DM was reduced with terminal node 5 (CpG3 methylation ≥72%, nonobesity, normal triglyceride (TG) level, and CpG4 methylation ≥83%) vs terminal node 1 (CpG3 methylation <72%) (odds ratio 95% CI 0.20, 0.10-0.40). CONCLUSIONS: TXNIP methylation is associated with T2DM incidence in a Chinese population. Interaction between TXNIP methylation and environmental factors may influence T2DM risk and needs more investigation.

Obstructive sleep apnea and risk of type 2 diabetes mellitus: A systematic review and dose-response meta-analysis of cohort studies.

BACKGROUND: This meta-analysis was performed to quantitatively evaluate the dose-response association between obstructive sleep apnea (OSA) and risk of type 2 diabetes mellitus (T2DM). METHODS: PubMed, Embase, and Web of Science were searched up to 12 December 2018 for articles that assessed the OSA-T2DM association. Random effects models were used to analyze the quantitative association between OSA and risk of T2DM. Restricted cubic splines were used to model the dose-response association between apnea-hypopnea index (AHI), used to assess the severity of OSA according to events/h, and risk of T2DM. RESULTS: We included 16 cohort studies in our meta-analysis. During a median follow-up of 10.5 years (range: 3.0-22.0), 19 355 T2DM cases were reported among 338 912 study participants. The pooled relative risk of T2DM was 1.40 (95% CI, 1.32-1.48) for OSA in the binary meta-analysis and 1.08 (1.01-1.14) for each 5-event/h increase in AHI value. We found a positive linear association between OSA and T2DM risk. CONCLUSIONS: Our dose-response meta-analysis revealed a linear association between OSA and T2DM.