Person:

Liang, J

Objective: The American Diabetes Association (ADA) recently published new clinical guidelines in which hemoglobin A1c (HbA1c) was recommended as a diagnostic test for diabetes. The present study was to investigate the association between HbA1c and cardiovascular risk, and compare the associations with fasting glucose and 2-hour oral glucose tolerance test (2 h OGTT). Research design and methods: The study samples are from a community-based health examination survey in central China. Carotid-to-femoral pulse wave velocity (cfPWV) and HbA1c were measured in 5,098 men and women. Results: After adjustment for age, sex, and BMI, the levels of HbA1c were significantly associated with an increasing trend of cfPWV in a dose-dependent fashion (P for trend <0.0001). The associations remained significant after further adjustment for blood pressure, heart rate, and lipids (P = 0.004), and the difference in cfPWV between the highest and the lowest quintiles of HbA1c was 0.31 m/s. Fasting glucose and 2 h OGTT were not associated with cfPWV in the multivariate analyses. HbA1c showed additive effects with fasting glucose or 2 h OGTT on cfPWV. In addition, age and blood pressure significantly modified the associations between HbA1c and cfPWV (P for interactions <0.0001 for age; and = 0.019 for blood pressure). The associations were stronger in subjects who were older ((\geq60 y; P for trend = 0.004)) and had higher blood pressure ((\geq 120 [systolic blood pressure]/80 mmHg [diastolic blood pressure]; P for trend = 0.028)) than those who were younger and had lower blood pressure (P for trend >0.05). Conclusions: HbA1c was related to high cfPWV, independent of conventional cardiovascular risk factors. Senior age and high blood pressure might amplify the adverse effects of HbA1c on cardiovascular risk.

Objective: To comprehensively examine the associations of serum uric acid (SUA) with central and peripheral arterial stiffness in Chinese adults, and particularly assess the interactions between SUA and other cardiometabolic risk factors. Methods: The study included 3,772 Chinese men and women with carotid radial pulse wave velocity (crPWV), carotid femoral PWV (cfPWV), carotid artery dorsalis pedis PWV (cdPWV) and SUA measured. Results: After adjustment for age, sex, and BMI, the levels of SUA were significantly associated with increasing trend of cfPWV, crPWV and cdPWV (P for trend <0.0001). Further adjustment for heart rate (HR), blood pressure (BP) and lipids attenuated the associations with crPWV and cdPWV to be non-significant (P = 0.1, P = 0.099 respectively), but the association between SUV and cfPWV remained significant (P = 0.004). We found significant interactions between SUA and HR or BP in relation to cfPWV (P for interaction = 0.03, 0.003 respectively). The associations between SUA and cfPWV were more evident among individuals with higher HR or normal BP than those with lower HR or hypertension. Conclusions: SUA was associated with elevated aortic arterial stiffness in Chinese adults, independent of conventional cardiovascular risk factors. BP and HR might modify the deleterious effects of SUA.

BACKGROUND: Circulating branched-chain amino acids and aromatic amino acids were recently related to insulin resistance and diabetes mellitus in prospective cohorts. We tested the effects of a genetic determinant of branched-chain amino acid/aromatic amino acid ratio on changes in body weight and insulin resistance in a 2-year diet intervention trial. METHODS AND RESULTS: We genotyped the branched-chain amino acid/aromatic amino acid ratio-associated variant rs1440581 near the PPM1K gene in 734 overweight or obese adults who were assigned to 1 of 4 diets varying in macronutrient content. At 6 months, dietary fat significantly modified genetic effects on changes in weight, fasting insulin, and homeostasis model assessment of insulin resistance (HOMA-IR) after adjustment for the confounders (all P for interaction ≤0.006). Further adjustment for weight change did not appreciably change the interactions for fasting insulin and HOMA-IR. In the high-fat diet group, the C allele was related to less weight loss and smaller decreases in serum insulin and HOMA-IR (all P ≤ 0.02 in an additive pattern), whereas an opposite genotype effect on changes in insulin and HOMA-IR was observed in the low-fat diet group (P=0.02 and P=0.04, respectively). At 2 years, the gene-diet interactions remained significant for weight loss (P=0.008) but became null for changes in serum insulin and HOMA-IR resulting from weight regain. CONCLUSIONS: Individuals carrying the C allele of the branched-chain amino acid/aromatic amino acid ratio-associated variant rs1440581 may benefit less in weight loss and improvement of insulin sensitivity than those without this allele when undertaking an energy-restricted high-fat diet. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00072995.