Does elevated serum uric acid level predict the hypertension incidence? A Chinese prospective cohort study

Traditional Chinese medicine in the treatment of patients with hyperuricemia: A randomized placebo-controlled double-blinded clinical trial

BACKGROUND

Studies have demonstrated the association of hyperuricemia with hypertension, metabolic syndrome, cardiovascular disease, and chronic renal disease. Although Western medicine presents promising effects for treating hyperuricemia and gout, identifying a safe and effective alternative to traditional Chinese medicine (TCM) for treating hyperuricemia is essential.

OBJECTIVE

To evaluate the efficacy and safety of TCM formulas, "Wu-Ling San" and "Yin Chen Wu-Ling San," in patients with hyperuricemia.

METHODS

A randomized, double-blinded, placebo-controlled clinical trial in adults with hyperuricemia was conducted. Sixty patients with serum urate level higher than 8 mg/dL were enrolled in the study. Patients were then randomized into three arms: "Wu-Ling San," "Yin Chen Wu-Ling San," and placebo for 4 weeks. Efficacy and safety were evaluated at weeks 2, 4, and 8. Primary and secondary endpoints were set to evaluate the serum urate concentration and related indicators at weeks 2, 4, and 8.

RESULTS

No significant differences were observed among the three arms in terms of the serum urate level (<6 mg/dL) at week 4. The serum urate level was lower in the "Yin Chen Wi-Ling" arm at week 8 (8.1 mg/dL vs. 9.1 mg/dL, p = .034). The serum urate levels were significantly different in both the "Wu-Ling San" and "Yin Chen Wu-Ling San" arms from those at the baseline (p < .05).

CONCLUSIONS

Two TCM formulas were found to be relatively safe for the short-term treatment of the patients with hyperuricemia. No statistically significant difference was observed in reaching the target-serum urate level <6 mg/dL.

Age and sex dependent association of uric acid and incident hypertension

BACKGROUND AND AIMS

A previous meta-analysis suggested that the relationship between hyperuricemia and hypertension may be stronger in younger individuals and women. We aimed to investigate the age and sex dependent association of uric acid (UA) and incident hypertension.

METHODS AND RESULTS

We analyzed data from the Health Examinees Study, a community-based prospective cohort study conducted in Korea from 2004 to 2013. It included 29,088 non-hypertensive subjects aged 40-79 (age, 52.5 ± 7.8 years; men, 31.4%) who had serum UA measurement and participated in the follow-up survey. The risk factors of hypertension were assessed using Cox regression. Over a mean 3.8 years of follow-up, 1388 men (15.2%) and 1942 women (9.7%) were newly diagnosed with hypertension. Upon age- and sex-based stratification, the risk of hypertension was highest in hyperuricemic subjects aged 40-49 years (HR: women, 2.16; men, 1.30). Across the entire cohort, the risk of incident hypertension was higher in groups with higher serum UA levels, and highest in women aged 40-49 years (HR, 1.44; P < 0.001). On multivariable linear regression analysis, the higher the baseline serum UA level, the greater the increase in blood pressure during follow-up, and this effect was strongest in women aged 40-49 years (β = 0.87 and P < 0.01 for systolic blood pressure).

CONCLUSIONS

The relationship between uric acid and incident hypertension tended to be dependent on age and sex. Younger women are at highest risk of UA-related incident hypertension.

A novel predicted model for hypertension based on a large cross-sectional study

Hypertension is a global public health issue and leading risk for death and disability. It is urgent to search novel methods predicting hypertension. Herein, we chose 73158 samples of physical examiners in central China from June 2008 to June 2018. After strict exclusion processes, 33570 participants with hypertension and 35410 healthy controls were included. We randomly chose 70% samples as the train set and the remaining 30% as the test set. Clinical parameters including age, gender, height, weight, body mass index, triglyceride, total cholesterol, low-density lipoprotein, blood urea nitrogen, uric acid, and creatinine were significantly increased, while high-density lipoprotein was decreased in the hypertension group versus controls. Nine optimal markers were identified by a logistic regression model, and achieved AUC value of 76.52% in the train set and 75.81% in the test set for hypertension. In conclusions, this study is the first to establish predicted models for hypertension using the logistic regression model in Central China, which provide risk factors and novel prediction method to predict and prevent hypertension.

Does obesity modify the epidemiological association between hyperuricemia and the prevalence of hypertension among Northern Chinese community-dwelling people? A Chinese population-based study

OBJECTIVES

Hyperuricemia and obesity both play a role in the development of hypertension. However, limited evidence is available for the combined effect of hyperuricemia and obesity on the prevalence of hypertension in the Chinese population. We aimed to assess the separate and combined effects of these two risk factors on the risk of hypertension.

METHODS

We conducted a cross-sectional study in an area of Dalian city, Liaoning Province, China, from September 2015 to November 2016; 8700 adult residents were invited to participate in this study. Hyperuricemia was defined as serum uric acid ≥ 416 μmol/L in men and ≥ 357 μmol/L in women according to the guidelines. Individuals were categorised into four groups: the control group (body mass index (BMI) §amp;lt; 25 without hyperuricemia, the reference group), the obesity group (BMI ≥ 25 without hyperuricemia), the hyperuricemia group (BMI §amp;lt; 25 with hyperuricemia) and the obese-hyperuricemia group (BMI ≥ 25 with hyperuricemia). A multivariable logistic model was used to investigate individual and combined effects of hyperuricemia and obesity on the risk of hypertension.

RESULTS

Of the 8331 individuals included, 44.3% were obese, 13.6% suffered from hyperuricemia, and 7.8% were both obese and hyperuricemic. The hypertension prevalence was the highest in the obese-hyperuricemia group (55.5% (95% CI 51.6% to 59.2%)), followed by that in the obesity (44.3% (42.6% to 46.1%)) and that in the hyperuricemia groups (33.5% (29.5% to 37.9%)). After adjusting for confounders, the obese-hyperuricemia group had a nearly threefold increased risk of hypertension compared with their healthy counterparts (OR 2.98 (2.48 to 3.57)). This pattern was also observed in the obesity group with a higher risk of hypertension (OR 2.18 (1.96 to 2.42)) compared with the control group, whereas the risk of hypertension was not elevated significantly in the hyperuricemia group (OR 1.14 (0.92 to 1.42)).

CONCLUSION

Our study provided the first evidence that obese Chinese individuals with hyperuricemia had a significantly increased risk of hypertension compared with their healthy counterparts. This combined effect on the risk of hypertension is much stronger than the individual effect of either factor.

Management of hyperuricemia and gout in obese patients undergoing bariatric surgery

BACKGROUND

Hyperuricemia and gout represent important issues in the obese patients. Considering the epidemic trend of overweight and obesity in developed countries, the impact of these conditions is likely to increase. At present, bariatric surgery represents the most effective treatment for the management of severe obesity for reducing weight and the impact of associated comorbidities, but its effects on hyperuricemia and gout have not been fully elucidated.

METHODS

In this narrative review, we discuss the current knowledge about hyperuricemia and gout in obese patients undergoing bariatric surgery. We also suggest a useful approach to prevent gouty attacks in the perioperative period.

RESULTS

Weight loss seems to reduce hyperuricemia in the long-term follow-up, but there is evidence also of a high frequency of acute attacks early after surgery in patients with a diagnosis of gout.

CONCLUSION

Bariatric surgery has a high impact on hyperuricemia and gout. A perioperative approach is suggested, based on appropriate hydration, early physical resumption, urate lowering drugs and nonsteroidal anti-inflammatory drugs (NSAIDs), or colchicine and corticosteroids if NSAIDs are ineffective or not tolerated.

Prehypertension and high serum uric acid increase risk of arterial stiffness

Prehypertension and serum uric acid are emerging as independent risk factors for arterial stiffness and may also predict cardiovascular diseases. Previous studies have demonstrated the association between serum uric acid and arterial stiffness in hypertensive adults, but there are limited studies in prehypertensive adults. We compared the serum uric acid (SUA) and cardio-ankle vascular index (CAVI) between normotensive and prehypertensive participants. The association between SUA, prehypertension and CAVI were investigated. One hundred and eighteen participants were recruited and divided into two groups according to their blood pressure (normotensive, 53 and prehypertensive, 65). Blood pressure, resting heart rate, pulsatile stress, height, waist circumference and body composition were measured. After an overnight fast, blood samples were collected to measure lipid profile and SUA levels. Arterial stiffness was assessed according to the CAVI. The results showed that the SUA and CAVI of the prehypertensive group were significantly higher than those of the normotensive group. Multiple regression analysis demonstrated that CAVI was significantly correlated with age, systolic blood pressure and SUA. Furthermore, prehypertension and high SUA were significantly associated with increased risk of abnormal CAVI (relative risk, 2.696; 95% CI, 1.552-4.683; p < .001). The study demonstrated that prehypertension and high SUA significantly increased the risk of arterial stiffness as assessed by CAVI.

The role of hyperuricemia on vascular endothelium dysfunction

Hyperuricemia appears to be associated with an increased risk for cardiovascular disease and associated mortality. Population epidemiological data support a causal link between hyperuricemia and cardiovascular disease. Endothelium injury could be one of the potential mechanisms in hyperuricemia-induced cardiovascular disease. However, the specific role of uric acid (UA) in the impairment of vascular relaxation and its signal transduction pathway has not been examined. The authors investigated the role of UA on vascular relaxation, nitric oxide (NO) production and expression of proinflammatory cytokines. Brachial flow-mediated dilation and nitroglycerine-mediated dilation were measured by B-mode ultrasound with 10 megahertz linear-array transducer from 21 patients with hyperuricemia and 16 control subjects. Human umbilical vein endothelial cells (ECs) were incubated with UA (5-15 mg/dl) with or without nuclear factor (NF)-κB inhibitor II. Hyperuricemia inhibited brachial flow-mediated dilation. While UA significantly inhibited NO expression with time course- and dose- dependent manner in the cultured ECs, 10 mg/dl UA also increased expression of inflammation cytokine interleukin (IL)-6, IL-8 and tumor necrosis factor-α in vitro. These abnormalities were associated with UA-induced activation of transcription factor NF-κB. Furthermore, NF-κB inhibitor II prevented UA-induced reduction of NO and increased inflammation cytokines. These data suggested hyperuricemia-induced endothelium injury and vascular dysfunction by a reduction of NO and expression of inflammatory cytokines through the NF-κB pathway.

Does the serum uric acid level have any relation to arterial stiffness or blood pressure in adults with congenital renal agenesis and/or hypoplasia?

BACKGROUND

The relationship between serum uric acid and arterial stiffness or blood pressure is not clear. The serum uric acid level and its association with cardiovascular risk is not well known in patients with reduced renal mass. We aimed to investigate the relation between serum uric acid levels and arterial stiffness and also blood pressure in patients with congenital renal agenesis and/or hypoplasia.

MATERIAL AND METHODS

In this single center, cross-sectional study, a total of 55 patients (39 (% 70.9) with unilateral small kidney and 16 (%29.1) with renal agenesis) were included. The median age was 35 (21-50) years. The study population was divided into tertiles of serum uric acid (according to 2.40-3.96, 3.97-5.10, and 5.11-9.80 mg/dl cut-off values of serum uric acid levels). Official and 24-h ambulatory non-invasive blood pressures of all patients were measured. The arterial stiffness was assessed by pulse wave velocity (PWV).

RESULTS

PWV values were increased from first to third tertile (5.5 ± 0.6, 5.7 ± 0.8, 6.1 ± 0.7, respectively), but this gradual increase between tertiles did not reach significance. Linear regression analyses showed a positive correlation between serum uric acid levels and PWV (β = 0.40, p = 0.010), but no correlation was found between uric acid and daytime systolic blood pressure (β = 0.24, p = 0.345).

CONCLUSION

In congenital renal agenesis/hypoplasia, the serum uric acid level was positively correlated with arterial stiffness, but there was no correlation with blood pressure.