Tingting Du

Clinical usefulness of lipid ratios, visceral adiposity indicators, and the triglycerides and glucose index as risk markers of insulin resistance

BackgroundTo directly compare traditional lipid ratios (total cholesterol [TC]/high density lipoprotein cholesterol [HDL-C], non-HDL-C/HDL-C, low density lipoprotein cholesterol [LDL-C]/HDL-C, and triglycerides [TG]/HDL-C), apolipoprotein B (apoB)/apolipoprotein A-I (apoA-I) ratio, visceral adiposity index (VAI), lipid accumulation product (LAP), and the product of TG and fasting glucose (TyG) for strength and independence as risk factors for insulin resistance (IR).MethodsWe conducted a cross-sectional analysis of 7629 Chinese adults using data from the China Health and Nutrition Survey 2009.ResultsFor all lipid ratios (traditional lipid ratios and apoB/apoA-I), among both sexes, TG/HDL-C explained the most additional percentage of variation in HOMA-IR (2.9% in men, and 2.3% in women); for all variables of interest, the variability in HOMA-IR explained by VAI and TG/HDL-C were comparable; TyG had the most significant association with HOMA-IR, which explained 9.1% for men and 7.8% for women of the variability in HOMA-IR. Logistic regression analysis showed the similar patterns. Receiver operating characteristic (ROC) curve analysis showed that, among both sexes, TG/HDL-C was a better discriminator of IR than apoB/apoA-I; the area under the ROC curve (AUC) for VAI (0.695 in men and 0.682 in women) was greater than that for TG/HDL-C (AUC 0.665 in men and 0.664 in women); TyG presented the greatest value of AUC (0.709 in men and 0.711 in women).ConclusionThe apoB/apoA-I performs no better than any of the traditional lipid ratios in correlating with IR. The TG/HDL-C, VAI and TyG are better markers for early identification of IR individuals.

Increasing trends in central obesity among Chinese adults with normal body mass index, 1993–2009

BackgroundCentral obesity is thought to be more pathogenic than overall obesity and studies have shown that the association between waist circumference (WC) and mortality was strongest in those with a normal body mass index (BMI). The objective of our study was to determine secular trends in the prevalence of central obesity (WC ≥ 90 cm for men and ≥ 80 cm for women) among Chinese adults with normal BMI from 1993 to 2009 and to examine the impact of performance of combined BMI and WC on the prevalence of obesity in Chinese adults.MethodsWe used data from the China Health and Nutrition Survey (CHNS) conducted from 1993 to 2009. From which we included a total of 52023 participants aged ≥ 18 years.ResultsThe age-standardized prevalence of central obesity among Chinese adults with BMI < 25 kg/m2 increased from 11.9% in 1993 to 21.1% in 2009 (P for linear trend <0.001). The upward trends were noted in both genders, all ages, rural/urban settings, and education groups (all P for linear trend <0.001), with greater increments in men, participants aged 18–64 years, and rural residents (P for interaction terms survey × sex, survey × age, and survey × rural/urban settings were 0.042, 0.003, and < 0.001, respectively). Trends in the prevalence of central obesity were similar when a more stringent BMI < 23 kg/m2 cut point (Asian cut point) was applied. Central obesity is associated with a higher risk of incident hypertension within normal BMI category. More than 65% individuals with obesity would be missed if solely BMI was measured.ConclusionsWe observed an upward trend in the prevalence of central obesity among participants with normal BMI irrespective of sex, age, rural/urban settings, and education level. Central obesity is associated with a higher risk of incident hypertension within normal BMI category. Approximately two thirds of the individuals with obesity would be missed if WC was not measured. It is, therefore, urgent to emphasize the importance of WC as a measure to monitor the prevalence of obesity.

Associations of serum uric acid levels with cardiovascular health factors:Differences by sex, age and body mass index in Chinese participants

BACKGROUND Recently, the American Heart Association developed a set of 3 ideal cardiovascular (CV) health factors. However, information on whether associations of uric acid (UA) with the CV health factors is influenced by sex, age, and body mass index (BMI) is limited. METHODS We conducted a cross-sectional analysis using a cohort of 10,420 people aged 20-100 years, who underwent health checkups in 2009. CV health factors were defined as untreated total cholesterol (TC)<200mg/dl, untreated systolic/diastolic blood pressure (BP)<120/80 mm Hg, and untreated fasting plasma glucose (FPG)<100mg/dl. RESULTS The association of UA with each CV health factor was gender-specific. The interaction terms (gender × UA level) comparing change in prevalence of each CV health factor between the 1st and 4th UA quartiles showed a significantly greater reduction among women (all P<0.01). In addition, the interactions between UA levels and age on prevalence of each CV health factor were statistically significant (all P<0.01). Furthermore, absolute reductions in the prevalence of ideal levels of BP, and TC across ordinal UA quartiles were greater in obese individuals than in overweight and normal-weight individuals (all P<0.01). Finally, UA showed a bell-curved relation with the prevalence of ideal FPG among all BMI categories. CONCLUSIONS Elevated UA inversely associated with each CV health factor and these associations were influenced by gender, age and BMI. Elevated UA levels should alert clinical suspicion for a potential coexistence of low frequency of CV health factors.

Lipid phenotypes in patients with nonalcoholic fatty liver disease

OBJECTIVE There has been conflicting evidence regarding the role of single lipid species in the pathogenesis of nonalcoholic fatty liver disease (NAFLD). We aimed to explore the associations between dyslipidemia phenotypes (combinations of lipid parameters) and the risk of NAFLD. METHODS We conducted a cross-sectional analysis using a cohort of 9560 apparently healthy Chinese adults who underwent comprehensive health checkups including abdominal ultrasonography. RESULTS Of 3709 participants with NAFLD, 41.8% were classified as normolipemia (NL), 3.8% as combined hyperlipidemia, 3.2% as hypercholesterolemia, 17.7% as dyslipidemia of metabolic syndrome (MetS), 10.2% as isolated low high-density lipoprotein cholesterol (HDL-C), and 23.3% as isolated hypertriglyceridemia. The multivariable-adjusted odds ratios (ORs) (with 95% confidence intervals) for NAFLD in those with combined hyperlipidemia, those with hypercholesterolemia, those with MetS dyslipidemia, those with low HDL-C, and those with hypertriglyceridemia compared with those with NL were 4.79 (3.19-7.20), 1.26 (0.94-1.69), 3.31 (2.74-3.99), 1.13 (0.95-1.34), and 2.63 (2.26-3.08), respectively. The associations between combined hyperlipidemia, MetS dyslipidemia, or hypertriglyceridemia and risk of NAFLD were consistently seen in various evaluated subgroups. The interactions between lipid phenotypes and sex, body mass index (BMI), blood pressure (BP), fasting plasma glucose (FPG), or uric acid (UA) were not significant for NAFLD (all P>0.05). CONCLUSIONS There were diverse dyslipidemia phenotypes in patients with NAFLD. Combined hyperlipidemia, MetS dyslipidemia, and hypertriglyceridemia were strongly and independently associated with increased risk of NAFLD. Gender, BMI, BP, FPG, and UA status did not modify the associations between dyslipidemia phenotypes and NAFLD.

Comparison of the performance of HbA1c and fasting plasma glucose in identifying dysglycaemic status in Chinese high-risk subjects.

The aim of the present study was to compare the performance of HbA1c and fasting plasma glucose (FPG) in identifying dysglycaemic status among Chinese participants. Fasting plasma glucose and HbA1c were measured in 2318 subjects with at least one risk factor for diabetes but without being previously diagnosed with diabetes. Using HbA1c to diagnose diabetes resulted in the same classification as FPG for 90.5% of the study participants, with 21.0% (n = 487) classified as having diabetes by both FPG and HbA1c and 69.5% (n = 1610) classified as not having diabetes by both FPG and HbA1c. The kappa (κ) coefficient of the FPG criterion with the HbA1c criterion for diabetes was 0.75 (95% confidence interval (CI) 0.72–0.78). The overlap index regarding diabetes diagnosed by FPG or HbA1c was 68.8%. Of 1610 subjects with FPG < 126 mg/dL and HbA1c < 6.5%, 220 (13.7%) had FPG ≥ 100 mg/dL and HbA1c < 5.7%, whereas 277 (17.2%) had FPG < 100 mg/dL and HbA1c ≥ 5.7%. The κ coefficient of the FPG criterion with the HbA1c criterion for prediabetes was 0.30 (95% CI 0.25–0.35). The overlap index between subjects diagnosed as having prediabetes by FPG of 100–125 mg/dL (impaired fasting glucose (IFG)) or HbA1c of 5.7–6.4% (increased HbA1c (IGH)) was 35.9%. The HbA1c criterion demonstrates reasonable concordance with the FPG criterion for diabetes. Hence, HbA1c and FPG can be used for the diagnosis of diabetes. However, the IGH shows limited overlap with IFG for prediabetes. Introduction of the IGH criterion in addition to IFG for the screening of prediabetes could lead to the identification of more people with this condition.

Combined effect of obesity and uric acid on nonalcoholic fatty liver disease and hypertriglyceridemia

Abstract Hyperuricemia is associated with metabolic syndrome (MetS), but the association is often confounded by the shared background of obesity. We sought to explore the modifying effects of obesity on the association between uric acid (UA), MetS components, and nonalcoholic fatty liver disease (NAFLD). We conducted a cross-sectional study in a Chinese population of 10,069 participants aged ≥20 years. Multiplicative interaction between obesity (BMI ≥25 kg/m2) and elevated UA was assessed using an interaction term in a logistic regression analysis. The presence of additive interaction was assessed based on the relative excess risk due to the interaction (RERI) and the attributable proportion due to the interaction (AP). There was no evidence of a multiplicative interaction between obesity and elevated UA on MetS components and NAFLD. However, there was a strong additive interaction between obesity and elevated UA with regard to NAFLD (RERI of 6.47 [95% CI 3.42–9.53] for men and 5.87 [1.55–10.19] for women) and hypertriglyceridemia (RERI of 1.38 [0.57–2.20] for men and 1.38 [0.08–2.67] for women). In addition, 42% and 36% of the increased odds of NAFLD for men and women, respectively, can be explained by an interaction between obesity and elevated UA (AP of 0.42 [95% CI (0.30–0.54)] for men and 0.36 [0.17–0.55] for women). Similarly, the interaction accounted for 27% and 26% of the increased risk of hypertriglyceridemia for men and women (AP of 0.27 [0.14–0.41] for men and 0.26 [0.06–0.47] for women). In this population, obesity and elevated UA synergistically interacted to increase the risk of NAFLD and hypertriglyceridemia.

Sex differences in the effect of HbA1c-defined diabetes on a wide range of cardiovascular disease risk factors

Abstract Objective Sex differences in the association of HbA1c and cardiovascular disease (CVD) risk remain controversial. We examined CVD risk profile in both HbA1c-defined diabetic and nondiabetic men and women. Methods We conducted a cross-sectional analysis of 7139 Chinese adults using data from the China Health and Nutrition Survey 2009. Results HbA1c-defined nondiabetic men have a more favorable CVD risk profile than female counterparts. However, HbA1c-defined diabetic men have higher levels of triglyceride, low-density lipoprotein (LDL)-cholesterol, and triglyceride/high-density lipoprotein (HDL)-cholesterol and lower levels of HDL-cholesterol, be more visceral obese as indicated by visceral adiposity index (VAI) and lipid accumulation product (LAP), and more insulin resistant as assessed by the triglycerides and glucose index (TyG) than HbA1c-defined diabetic women. Furthermore, HbA1c-defined diabetic men showed greater relative differences in ferritin than diabetic women when compared with their nondiabetic counterparts. Statistically significant sex by HbA1c-defined diabetes status interactions were observed for triglyceride, LDL-cholesterol, HDL-cholesterol, triglyceride/HDL cholesterol, VAI, LAP, TyG, and ferritin (all ps < 0.05). Consideration of VAI or homeostasis model assessment of insulin resistance or both failed to eliminate the sex differences in the associations between diabetes and these CVD risk factors. Conclusions Men who progressed from HbA1c-defined nondiabetes to HbA1c-defined diabetes have greater metabolic deteriorations and put on more visceral adiposity than women. Key messages HbA1c-defined nondiabetic men have a more favorable CVD risk profile than female counterparts. Men have to undergo a greater metabolic deterioration to develop HbA1c-defined diabetes than do women. Men have to put on more visceral adiposity to develop HbA1c-defined diabetes than do women.

Trends in cardiovascular risk factors among U.S. men and women with and without diabetes, 1988–2014

BackgroundStudies evidenced that reduction in cardiovascular disease (CVD) mortality in diabetic patients can be attributed to improvements in major CVD risk factors and evidence-based treatments. Furthermore, studies showed that the relative risk of CVD mortality associated with diabetes compared with non-diabetes is stronger in women than in men. Hence, we aimed to examine trends in CVD risk factors and intervention measures by sex and diabetic status.MethodsAnalysis of 5 distinct cross-sectional National Health and Nutrition Examination Surveys, 1988–1994, 1999–2002, 2003–2006, 2007–2010, and 2010–2014. Since detailed information on nontraditional risk factors such as sleep apnea was not available in each NHANES survey, traditional CVD risk factors including obesity, hypertension, and dyslipidemia were assessed in the study. To assess whether changes throughout the 27-year period differed by diabetes status, a logistic regression analysis was utilized to examine potential interaction effects between survey and diabetes. The similar process was repeated for sex.ResultsMeans of all risk factors except body mass index and waist circumference decreased and the prevalence of antihypertensive and lipid-lowering medication use increased over time among diabetic and non-diabetic men and women. For both men and women, survey × diabetes status interaction terms for changes in HDL-cholesterol and triglyceride levels were not statistically significant, while the prevalence of antihypertensive and lipid-lowering medication use increased more in diabetic than in non-diabetic persons (all P < 0.001). For women, survey × diabetes status interaction terms indicated that compared with the first survey, total cholesterol, LDL-cholesterol, and non-HDL-cholesterol fallen more in diabetic than in non-diabetic persons (all P < 0.001). In the diabetic state, men experienced similar changes in means of all CVD risk factors and the prevalence of antihypertensive and lipid-lowering medication use as women (all P for interactions between survey and sex were >0.01).ConclusionsThe major traditional CVD risk factors in diabetic men decreased to the same extent that they did for non-diabetic men. The magnitude of changes in the favorable trends in diabetic women was of similar or greater compared with those among non-diabetic women. Diabetic women had as good an improvement in CVD risk factors as diabetic men.

Non-HDL cholesterol and LDL cholesterol in the dyslipidemic classification in patients with nonalcoholic fatty liver disease

BackgroundLow-density lipoprotein cholesterol (LDL-C) always underestimates the true cholesterol burden in patients with nonalcoholic fatty liver disease (NAFLD). We aimed to compare LDL-C and non-high-density lipoprotein cholesterol (non-HDL-C) in the identification of high-risk dyslipidemic phenotypes in those with NAFLD.MethodsWe conducted a cross-sectional analysis using a cohort of 9560 apparently healthy Chinese adults who underwent comprehensive health checkups including abdominal ultrasonography.ResultsAmong 3709 patients with NAFLD, the prevalence of abnormal LDL using LDL-C was 68.5%, whereas the prevalence was relatively lower when using non-HDL-C (55.9%). The concordance between non-HDL-C- and LDL-C-based diagnoses of abnormal LDL was similar in the hypertriglyceridemic (ҝ = 0.56; 95% CI 0.52–0.60) and normotriglyceridemic subgroups (ҝ = 0.47; 95% CI 0.44–0.51). Non-HDL-C detected fewer patients with abnormal LDL than LDL-C in normotriglyceridemic patients. However, non-HDL-C detected more patients with abnormal LDL than LDL-C in hypertriglyceridemic patients: 114 of the 1662 patients considered as abnormal LDL according to LDL-C fell into the normonon-HDL-C phenotype, whereas 204 of the 1662 patients considered as abnormal LDL according to non-HDL-C fell into the normoLDL-C phenotype.ConclusionAmong patients with NAFLD, LDL-C is superior to non-HDL-C in the detection of high-risk phenotypes in normotriglyceridemic patients, whereas non-HDL-C seems to be superior in hypertriglyceridemic patients.