Is hyperuricaemia a predictor of cardiovascular risk?:

Combination of hyperuricemia and metabolic syndrome is an independent and powerful predictor for left ventricular hypertrophy in rural Chinese

OBJECTIVES

To investigate the influence of MetS (metabolic syndrome) in combination with hyperuricemia on left ventricular hypertrophy (LVH) in residents in the rural area of Northeast China.

METHODS

We performed a cross-sectional baseline data analysis of 11,170 subjects (mean age: 54±11years) recruited from the rural area of China. Anthropometric indicators were measured according to standard methods. MetS was defined by the ATP III modified criteria. Hyperuricemia was defined according to sex-specific serum uric acid levels (SUA): SUA≥7.0mg/dL for male and≥6.0mg/dL for female. Four groups were listed: normouricemia non-MetS, hyperuricemia non-MetS, MetS normouricemia and hyperuricemia MetS.

RESULTS

Left ventricular mass index for height(2.7) (LVMH(2.7)) in female was significantly higher in hyperuricemia MetS group than that in normouricemia non-MetS (52.43±16.60 vs. 40.04±10.72g/m(2.7), P<0.001) group. Similar result was observed in men (48.93±13.17g/m(2.7) vs. 43.63±11.90g/m(2.7), P<0.001). The result of multiple regression analysis indicated that hyperuricemia MetS group had higher risk of LVH than other three groups (OR: 3.427 for female, P<0.001, OR: 1.987 for male, P<0.001). Moreover, female subjects in MetS normouricemia group [OR (95% CI): 2.313 (1.991-2.686)] had greater risk of LVH than that in hyperuricemia non-MetS group [OR (95% CI): 1.917 (1.166-3.151)]. Hyperuricemia non-MetS was found to be significantly and independently associated with LVH in women, but not in men.

CONCLUSION

Our study finds that the combination of hyperuricemia and MetS are independent and powerful predictor for LVH in rural area of Northeast Chinese. Women with MetS in combination with hyperuricemia have higher risk of LVH than men. It seems that MetS has greater effect on LVH than hyperuricemia does in women but not in men.

Relation between serum uric acid and carotid intima-media thickness in healthy postmenopausal women

OBJECTIVE

Serum uric acid (SUA) is associated with cardiovascular disease (CVD). However it is still disputed whether the relationship is mediated by other risk factors such as obesity, dyslipidaemia, hypertension and insulin resistance. We explored the association of the uric acid level with carotid intima-media thickness (IMT), a well known marker of CVD, in postmenopausal healthy women.

METHODS

We consecutively enrolled postmenopausal women undergoing a screening for health evaluation. After an accurate clinical examination, and a biochemical evaluation, the enrolled subjects underwent B mode ultrasonography to assess common carotid intima media thickness.

RESULTS

Among 234 women aged 45-70 years, the uric acid level is associated with carotid IMT independently of other prognostic factors (p=0.03). In particular, women in the highest tertiles of uric acid level have a greater IMT than women in the lowest tertile (p=0.007).

CONCLUSIONS

Independently of other cardiovascular risk factors, SUA levels are associated with carotid IMT even in subjects without the metabolic syndrome. This confirms and expands the role of uric acid in the determinism of CVD. Prospective trials would be useful to evaluate interventions aimed at lowering the uric acid level.

Prevalence and risk factors associated with dyslipidaemia in children and adolescents among ethnic groups in Taiwan

BACKGROUND

The mortality rates of cerebral and cardiovascular diseases are higher for aborigines than non-aborigines in Taiwan. Hypertriglyceridaemia and hypercholestolaemia are risk factors for cardiovascular diseases.

OBJECTIVES

To investigate the prevalence of dyslipidaemia and its associated risk factors in aborigine (Atayal, Paiwan and Bunun tribes) and non-aborigine (Fukein and Hakka Chinese) children and adolescents in Taiwan.

STUDY DESIGN

This was a cross-sectional study.

METHODS

In total, 718 males and 721 females, below 20 years of age, were recruited. Our study defined dyslipidaemia as serum triglyceride and cholesterol levels greater than 200 and 240 mg/dl, respectively.

RESULTS

The serum triglyceride level and the prevalence of hypertriglyceridaemia were similar in both aborigines and non-aborigines and both sexes, but the Bunun and Paiwan tribes had the highest prevalence of hypertriglyceridaemia in males (11.8-29.4%) and females (10.9-22.8%) compared with other aboriginal tribes (5.1-10.8% for males and 7.8-9.2% for females). Serum cholesterol concentrations and the prevalence of hypercholesterolaemia were lower in the aborigines than non-aborigines for both sexes (P<0.05), with the Atayal tribe having the lowest prevalence in males (1.1%) and females (2.1%) compared with other aboriginal tribes (2.4-4.5% for males and 5.7-8.0% for females). Using multivariate-adjusted logistic regression modelling, hypertriglyceridaemia was significantly associated with the Bunun tribe (odds ratio (OR)=3.2, 95% confidence intervals (CI) 1.6-6.1), hyperuricaemia (OR=1.8, 95% CI 1.2-2.6), hypercholesterolaemia (OR=3.3, 95% CI 1.7-6.4) and alcohol use (OR=2.8, 95% CI 1.2-6.6). Hypercholesterolaemia, after controlling for age and sex, was significantly associated with the Atayal tribe (OR=0.2, 95% CI 0.1-0.5), hypertriglyceridaemia (OR=3.5, 95% CI 1.8-6.7) and hyperuricaemia (OR=3.2, 95% CI=1.7-6.0).

CONCLUSIONS

For the young people of Taiwan, hypertriglyceridaemia is associated with hyperuricaemia, hypercholesterolaemia and alcohol use, and hypercholesterolaemia is associated with hypertriglyceridaemia and hyperuricaemia. Compared with non-aborigines, the young aborigines of some tribes have a higher prevalence of hypertriglyceridaemia and a lower serum cholesterol level.

Prevalence of hyperuricemia and relation of serum uric acid with cardiovascular risk factors in a developing country

BACKGROUND

The prevalence of hyperuricemia has rarely been investigated in developing countries. The purpose of the present study was to investigate the prevalence of hyperuricemia and the association between uric acid levels and the various cardiovascular risk factors in a developing country with high average blood pressures (the Seychelles, Indian Ocean, population mainly of African origin).

METHODS

This cross-sectional health examination survey was based on a population random sample from the Seychelles. It included 1011 subjects aged 25 to 64 years. Blood pressure (BP), body mass index (BMI), waist circumference, waist-to-hip ratio, total and HDL cholesterol, serum triglycerides and serum uric acid were measured. Data were analyzed using scatterplot smoothing techniques and gender-specific linear regression models.

RESULTS

The prevalence of a serum uric acid level >420 micromol/L in men was 35.2% and the prevalence of a serum uric acid level >360 micromol/L was 8.7% in women. Serum uric acid was strongly related to serum triglycerides in men as well as in women (r = 0.73 in men and r = 0.59 in women, p < 0.001). Uric acid levels were also significantly associated but to a lesser degree with age, BMI, blood pressure, alcohol and the use of antihypertensive therapy. In a regression model, triglycerides, age, BMI, antihypertensive therapy and alcohol consumption accounted for about 50% (R2) of the serum uric acid variations in men as well as in women.

CONCLUSIONS

This study shows that the prevalence of hyperuricemia can be high in a developing country such as the Seychelles. Besides alcohol consumption and the use of antihypertensive therapy, mainly diuretics, serum uric acid is markedly associated with parameters of the metabolic syndrome, in particular serum triglycerides. Considering the growing incidence of obesity and metabolic syndrome worldwide and the potential link between hyperuricemia and cardiovascular complications, more emphasis should be put on the evolving prevalence of hyperuricemia in developing countries.