[Association between serum uric acid and subclinical cardiac damage in children with primary hypertension]

OBJECTIVE

To evaluate the condition of subclinical cardiac damage in children with primary hypertension and the association between serum uric acid and subclinical cardiac damage.

METHODS

A retrospective analysis was performed on the medical data of 55 children who were hospitalized and diagnosed with primary hypertension in the Department of Cardiology, Children's Hospital of Soochow University from January 2015 to June 2020. Forty-five healthy children, matched for age and sex, were enrolled as the control group. The two groups were compared in terms of clinical features, laboratory examination, and parameters for left ventricular structure, systolic function, and diastolic function. The correlation of serum uric acid with the parameters for left ventricular structure, systolic function, and diastolic function in children with primary hypertension was analyzed.

RESULTS

Compared with the control group, the hypertension group had significantly higher left ventricular mass (LVM), left ventricular mass index (LVMI), and relative wall thickness (RWT) (P < 0.05). Among the children with primary hypertension, 20 (36%) had left ventricular hypertrophy. The hypertension group had significantly larger left atrial diameter and aortic root diameter than the control group (P < 0.05). The hypertension group had a significantly higher ratio of early diastolic mitral inflow velocity to early diastolic mitral annular velocity than the control group (P < 0.05). The correlation analysis showed that in children with primary hypertension, serum uric acid was positively correlated with LVM (r=0.534, P < 0.01), left atrial diameter (r=0.459, P < 0.01), and aortic root diameter (r=0.361, P=0.010). After adjustment for blood pressure, serum uric acid was still positively correlated with the above parameters (P < 0.05).

CONCLUSIONS

Children with primary hypertension may have subclinical cardiac damage such as left ventricular hypertrophy, left ventricular diastolic dysfunction, left atrial enlargement, and proximal aortic dilation. Elevated serum uric acid is significantly associated with cardiac damage in children with primary hypertension.

Reference intervals for serum 1,5-anhydroglucitol of a population with normal glucose tolerance in Jiangsu Province

BACKGROUND

Serum 1,5-anhydroglucitol (1,5-AG) is a new glycemic marker which can reflect glucose fluctuation over 3 to 7 days and is now increasingly used to monitor glucose control and to screen for diabetes. However, 1,5-AG has not been widely used in China due to lack of epidemiological support. Our study aims to establish the reference intervals for a population with normal glucose tolerance in Jiangsu Province and to explore the determinants of these intervals.

METHOD

The study enrolled 646 healthy adults aged 20 to 70 years in Jiangsu Province in 2018 after oral glucose tolerance test. 1,5-AG, fasting and 2-hour glucose, UA, liver enzyme, serum lipid, creatinine, and glycosylated hemoglobin were measured. We calculated reference intervals using the parametric method and examined the relationship between 1,5-AG and influence factors.

RESULTS

The average age of the participants was 50.5 ± 9.0 years, and 69.5% of them were females. The reference intervals were 15.8 to 52.6 μg/mL for males and 14.3 to 48.0 μg/mL for females. Among females, the reference intervals were 13.9 to 45.3 and 14.6 to 49.6 μg/mL for menopausal and postmenopausal females, respectively. Males showed higher 1,5-AG concentrations than females, and postmenopausal females had higher 1,5-AG than menopausal females. There was a positive correlation between uric acid and 1,5-AG in both genders. Positive correlation between 1,5-AG and age was only observed in females.

CONCLUSION

We established reference intervals for 1,5-AG in Jiangsu Province, and the level of 1,5-AG is affected by sex, uric acid, and age.

Fructose tolerance test in obese people with and without type 2 diabetes

BACKGROUND

Fructose is distinct among common sugars in its ability to raise serum uric acid, and some studies suggest fructose-induced uric acid production may have a role in the ability of this sugar to induce metabolic syndrome. A fructose tolerance test has been previously developed to evaluate the relative ability of fructose to raise uric acid in individuals. However, the effect of fructose to raise uric acid in people with diabetes has not been studied.

METHODS

People with type 2 diabetes (n = 143) and without diabetes controls (n = 132) with similar body mass index (BMI) underwent an oral fructose tolerance test. As a comparison, participants also had their uric acid levels measured after an oral glucose tolerance test on a different day.

RESULTS

Serum uric acid was lower in people with type 2 diabetes compared to controls with a similar BMI, especially those with poor glucose control (glycosylated hemoglobin [HbA1c] ≥ 8%). Fructose administration raised serum uric acid in both groups, with a lower absolute rise in people with diabetes. People with diabetes with a blunted rise in serum uric acid had higher baseline serum uric acid concentrations and a higher BMI. People without diabetes with a higher BMI also showed a blunted serum uric acid response. Oral glucose administration lowered serum uric acid in both participants, with a greater fall in those with diabetes.

CONCLUSION

Both the presence of diabetes and obesity blunt the serum uric acid response to fructose ingestion. These data demonstrate altered fructose-dependent urate metabolism in type 2 diabetes.

Different-shaped curves for serum uric acid with and without diabetes: Results from China Health and Retirement Longitudinal Study

BACKGROUND

Several studies have revealed conflicting results regarding the relationship between serum uric acid (SUA) and blood glucose concentrations. The aim of this study was to identify the shape of the curve between SUA and either fasting plasma glucose (FPG) or HbA1c in diabetic and non-diabetic participants.

METHODS

This cross-sectional study of the relationship between SUA and diabetes and non-diabetes was conducted in 10 266 participants. Data from the national baseline survey of the China Health and Retirement Longitudinal Study (CHARLS; 2011-12) were used. Restrictive cubic spline regression and two piecewise linear regression models were used to detect non-linear trends and calculate the slope of each segment.

RESULTS

After adjusting for all confounding factors in all subjects, an L-shaped relationship was found between FPG and SUA in males (β₂  = 3.47, P < 0.01) and females (β₂  = 5.84, P < 0.01), as well as between HbA1c and SUA in males (β₂  = 0.10, P = 0.03) and females (β₂  = 0.12, P = 0.02). In non-diabetic individuals, there was a positive linear correlation between FPG and SUA in females (β = 0.62, P = 0.02). After a diagnosis of diabetes, a negative linear relationship was found between SUA and blood glucose in males, and a nearly L-shaped curve was found in females.

CONCLUSIONS

An L-shaped association was found between SUA and blood glucose in both genders. Stratified analysis revealed an L-shaped curve only in diabetic females. Further studies are warranted to investigate the mechanisms of the association between uric acid and blood glucose levels.