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

Uric acid and risk of gestational diabetes mellitus: an observational study and mendelian randomization analysis

OBJECTIVE

Our aim was to explore the relationship between serum uric acid (UA) levels in early pregnancy and the development of gestational diabetes mellitus (GDM), and to further explore whether there is a causal relationship.

METHODS

684 pregnant women with GDM and 1162 pregnant women without GDM participated in this study. 311 pregnant women with GDM and 311 matched controls were enrolled in a 1:1 case-control study. We used conditional logistic regression to explore the relationship between UA levels and the risk of developing GDM. The causal relationship between the two was examined by two-sample Mendelian randomization (MR) analysis.

RESULTS

In the 1:1 matched population, the odds ratio (OR) of developing GDM compared with the extreme tertiles of UA levels was 1.967 (95% confidence interval [CI]: 1.475-2.625; P < 0.001). Restricted cubic spline analyses showed a linear relationship between UA and GDM when UA exceeded 222 µmol/L. GDM and UA levels maintained a statistically significant positive correlation in different stratified regression analyses (P < 0.001). However, no evidence of a causal relationship between uric acid and GDM was found by MR analyses with an OR of 1.06 (95% CI: 0.91-1.25) per unit increase in UA.

CONCLUSION

There is a positive correlation between UA levels in early pregnancy and the subsequent risk of developing GDM. However, no genetic evidence was found to support a cause-effect relationship between UA and GDM.

Diabetes mellitus as a risk factor and comorbidity in gout

INTRODUCTION

Metabolic disorders are a public health issue because of the complications they cause, but they are also a major risk factor for the onset of gout.

Uric acid played a role in the association between gender and deep vein thrombosis in patients with stroke

BACKGROUND AND AIMS

Gender-specific differences were found in serum uric acid (SUA) levels and the risk of isolated distal deep vein thrombosis (IDDVT). This study aimed to explore the association among gender, SUA, and IDDVT in stroke patients.

METHODS AND RESULTS

Finally, 3404 patients were recruited and divided into two groups: IDDVT (n = 1233) and Non-IDDVT (n = 2171) groups. Propensity score matching (PSM) was conducted to match the patients. Binary logistic regression was adopted to explore the association between SUA and IDDVT, with the SUA divided into quartiles. After PSM, 975 patients were included in each group. Non-IDDVT group had a larger proportion of male than IDDVT group (64.9% vs. 52.7%, p < 0.001). Moreover, males showed higher SUA levels than females (316.7 ± 102.1 vs. 261.8 ± 94.0 μmol/L, t = 12.1, p < 0.001). The highest quartile of SUA (≥346 μmol/L) showed a lower risk of IDDVT (OR = 0.629, p = 0.001), while the lowest quartile (≤225 μmol/L) showed a higher risk of IDDVT (OR = 1.361, p = 0.022).

CONCLUSION

In patients with stroke, SUA played a protective role in IDDVT. Females had a higher risk of IDDVT, which may be owing to the lower SUA levels than males. In clinical practice, more attention should be paid to the risk of IDDVT in females, especially those with lower SUA levels.

Association between plasma uric acid and insulin resistance in type 2 diabetes: A Mendelian randomization analysis

OBJECTIVE

Circulating uric acid levels were associated with insulin resistance, but the causality is unclear. We aimed to investigate the association between plasma uric acid and insulin resistance in newly diagnosed type 2 diabetes (T2D).

METHODS

We enrolled 1,938 patients who underwent a 75-g oral glucose tolerance test. Insulin resistance was estimated based on the homeostatic model assessment index (HOMA2-IR) and the Matsuda index. Uric acid was measured in fasting plasma by uricase-peroxidase method. We genotyped single nucleotide polymorphisms (SNPs) that were recently identified as top hits in genome-wide association studies of uric acid levels. A weighted genetic risk score (wGRS) was calculated based on the associations between selected SNPs and uric acid levels.

RESULTS

The adjusted β coefficients for Ln-transformed Matsuda index and HOMA2-IR per 1 mg/dL uric acid increment were -0.070 (95%CI: -0.089, -0.052) and 0.057 (95%CI: 0.039, 0.075). These associations were more pronounced among women than men. In Mendelian randomization analysis, the wGRS raised uric acid by 0.225 mg/dL (95%CI: 0.138, 0.312) per SD increase of the score. However, no association was observed between the wGRS and insulin resistance indices whether in men or women.

CONCLUSIONS

Elevated plasma uric acid was associated with higher risk of insulin resistance, along with observation of gender difference in such association. However, our study does not support a causal role of plasma uric acid on insulin resistance among newly diagnosed T2D patients.

Effects of Uric Acid on Diabetes Mellitus and Its Chronic Complications

With the deepening of the researches on uric acid, especially in the study of metabolic diseases, uric acid has been found to be closely related to obesity, metabolic syndrome, nonalcoholic fatty liver disease, diabetes, and other metabolic diseases. Uric acid causes a series of pathophysiological changes through inflammation, oxidative stress, vascular endothelial injury, and so on and thus subsequently promotes the occurrence and development of diseases. This review confirmed the positive correlation between uric acid and diabetes mellitus and its chronic complications through the pathogenesis and clinical studies aspects.

Added predictive value of high uric acid for cardiovascular events in the Ambulatory Blood Pressure International Study

The prognostic value of uric acid (UA) for cardiovascular events (CVE) is still debated. Our purpose was to investigate the association between UA and CVE in 5243 participants of the ABP-International study with the main aim of identifying optimal sex-specific cut-points. In multivariable Cox analyses, the relationship between CVE and UA as a continuous variable was modeled by including both linear and nonlinear terms. Survival models were also estimated with UA as a categorical variable. Optimal UA cut-points were determined using an outcome-oriented approach. During a median follow-up of 5.9 years, there were 423 CVE (93 fatal). In age- and sex-adjusted Cox models, UA as a continuous variable was a significant predictor of CVE in all individuals and in men and women considered separately. The relationship between UA and CVE was linear (P-value for nonlinearity 0.54 and 0.80 for men and women, respectively). For each 1 mg/dL increase in UA, the relative hazard increase was 16% in men and 19% in women. In fully adjusted models, UA remained a significant predictor of CVE in the whole study cohort. The optimal cut-point best separating patients at low and high risk of CVE was 6.3 mg/dL for men and 4.4 mg/dL for women. Subjects with high UA had a 38% greater risk of CVE. In a sex-specific analysis, the association remained significant only in men (hazard ratio, 1.47; P < 0.01). In conclusion, high UA is an independent predictor for subsequent CVE and significantly improves risk discrimination and reclassification over the baseline multivariable model.

The association between elevated serum uric acid levels and islet β-cell function indexes in newly diagnosed type 2 diabetes mellitus: a cross-sectional study

Background

Serum uric acid (UA) has been reported as a risk factor for type 2 diabetes mellitus (T2DM). However, whether serum UA is associated with insulin resistance and insulin secretion, and the effect of gender on it in the case of the existed association, both remain undefined.

Methods

A cross-sectional study was designed and performed, which enrolled a total of 403 newly diagnosed T2DM patients (mean age, 50.21 ± 13.34 years (62.5% males)). Clinical characteristics and islet function indexes of all participants were analyzed based on gender-specific tertiles of serum UA levels. In addition, multiple linear regression analysis was conducted to investigate covariates associated with islet function indexes.

Results

The mean levels of serum UA were 331.05 μmol/L (interquartile range (IQR): 60.6, 400.9 μmol/L) and 267.9 μmol/L (IQR: 204.7, 331.9 μmol/L) in men and women, respectively. The values of insulin secretion indexes involving AUCins30/glu30, AUCins120/glu120 and total insulin disposition index (DI120) in females were significantly higher than those in males. Apart from the homeostasis model assessment insulin resistance of men, serum UA was positively associated with insulin secretion and insulin resistance indexes both in men and women. Multivariable linear regression analysis showed serum UA exerted an independent impact on insulin secretion in females, but not on insulin resistance. In males, islet function was simultaneously affected by serum UA age, body mass index (BMI), and serum lipids.

Conclusion

Serum UA harbored a positive correlation with insulin secretion and insulin resistance indexes in newly diagnosed T2DM patients, which was influenced by gender, BMI, serum lipids. Hence, serum UA may be considered as a predictor for islet function in clinical practice.

Triglyceride glucose-body mass index is effective in identifying nonalcoholic fatty liver disease in nonobese subjects

Nonalcoholic fatty liver disease (NAFLD) is an increasingly common condition that is highly correlated with obesity; however, it is not uncommon among nonobese individuals. Triglyceride (TG) and glucose index combined with body mass index (TyG-BMI) has been proposed as a favorable marker of insulin resistance. We sought to investigate the effectiveness of TyG-BMI in identifying NAFLD in nonobese subjects.We conducted a cross-sectional study in a nonobese (BMI <25.0 kg/m) Chinese population (N = 6809) of adults who underwent health examinations, including abdominal ultrasonography.The prevalence of ultrasonography-detected NAFLD was 23.9% in nonobese subjects. After adjusting for potential confounders, every 1-standard deviation increase in TyG-BMI had an odds ratio (OR) of 3.4 [95% confidence interval (95% CI), 3.0-3.9] for NAFLD. Compared with the lowest quartile of TyG-BMI, multivariable-adjusted ORs were 2.4 (1.6-3.6), 6.4 (4.2-9.7), and 15.3 (9.8-23.9) for those in the second, third, and fourth quartile, respectively. According to the receiver operating characteristic curve analysis, TyG-BMI was effective in diagnosing patients with NAFLD with an area under the curve of 0.835 (95% CI, 0.824-0.845). In comparison, TyG-BMI was superior to its components, including TyG, BMI, TG, and fasting plasma glucose, for identifying nonobese subjects at risk for NAFLD.In this study, the prevalence of NAFLD was over one-fifth in the nonobese population. TyG-BMI was an effective marker to detect NAFLD in nonobese subjects.

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

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/m) 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.

The triglyceride and glucose index (TyG) is an effective biomarker to identify nonalcoholic fatty liver disease

Background

The triglyceride and glucose index (TyG) has been proposed as a marker of insulin resistance. We aimed to investigate the ability of TyG, through comparing with the predictive value of alanine aminotransferase (ALT), to identify individuals at risk for nonalcoholic fatty liver disease (NAFLD).

Methods

A cross-sectional study was conducted in a Chinese health examination cohort of 10 761 people aged above 20 years. NAFLD was diagnosed by ultrasonography.

Results

Compared with the participants in the lowest quartile of TyG, the adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for NAFLD were 1.8 (1.5–2.1), 3.0 (2.5–3.5), and 6.3 (5.3–7.5) for those in the second, the third, and the fourth quartile of TyG, whereas the corresponding ORs (95% CI) for NAFLD were 1.5 (1.3–1.7), 1.9 (1.6–2.2), and 3.1 (2.6–3.7) for the upper three quartiles of ALT. These results suggested that TyG was superior to ALT in association with NAFLD risk. According to the ROC analysis, the optimal cut-off point of TyG for NAFLD was 8.5 and the area under the ROC curve (AUC) was 0.782 (95% CI 0.773–0.790), with 72.2 and 70.5% sensitivity and specificity, respectively. The AUC of TyG was larger than that of ALT (0.715 (95% CI 0.705–0.725), P for difference <0.0001), whereas the largest AUC was obtained when adding TyG to ALT (0.804 (95% CI 0.795–0.812), P for difference <0.0001).

Conclusions

TyG is effective to identify individuals at risk for NAFLD. A TyG threshold of 8.5 was highly sensitive for detecting NAFLD subjects and may be suitable as a diagnostic criterion for NAFLD in Chinese adults.

Electronic supplementary material

The online version of this article (doi:10.1186/s12944-017-0409-6) contains supplementary material, which is available to authorized users.

Changes in Cardiovascular Health Status and the Risk of New-Onset Hypertension in Kailuan Cohort Study

American Heart Association cardiovascular health metrics are intimately related to cardiovascular diseases. Acting as a key independent risk factor for high morbidity and mortality of cardiovascular diseases, hypertension and its relationship between health status get urgent attention. While the influence of individual health status changes and the future risk of new-onset hypertension is rarely understood, the present study applied this construct to assess the changes of cardiovascular health status and the morbidity of hypertension in Kailuan cohort study in north China. The Cardiovascular Health Score (CHS) was evaluated by the follow-ups of 2006–2007, 2008–2009, 2010–2011 and 2012–2013. The study population (n = 19381) was divided into 5 groups based on the changes in their CHS score between the first two follow-ups (△CHS) of 2006–2007 and 2008–2009 (≤-2, -1, 0, 1, ≥2). The morbidity of hypertension was collected during 2010–2011 and 2012–2013 follow-ups. Data analysis showed that during a median follow-up of 3.79±0.96 years, morbidity of hypertension had a graded relationship with △CHS. As △CHS scored from low to high, the standardized morbidity of hypertension for all participants were 81.40, 75.47, 68.37, 71.43 and 83.13 per 1000 person-year, respectively. An increased △CHS score of 1 was associated with a 10% decrease in the future risk of new-onset hypertension(HR: 0.90, 95% CI: 0.88–0.92). In conclusion, there was a strong inverse relationship between the incidence of new-onset hypertension and elevation of cardiovascular health metrics. Population-wide prevention, especially the promotion of lifestyle improvements, is critical to reducing the morbidity of new-onset hypertension.