Change in serum uric acid between baseline and 1-year follow-up and its associated factors in male subjects

Long-term increase in serum uric acid and its predictors over a 25 year follow-up: Results of the PAMELA study

BACKGROUND AND AIMS

Hyperuricemia (HU) has been shown to be associated with an adverse impact on cardiovascular and metabolic risk. Scanty data are available in the general population on the longitudinal changes in serum uric acid (SUA), the occurrence of HU and their potential predictors. We examined during a 25-year follow-up the SUA changes and the factors associated with HU development in the Pressioni Arteriose Monitorate E loro Associazioni (PAMELA) study.

METHODS AND RESULTS

We analyzed data collected in 561 subjects of the PAMELA study evaluated during an average follow-up time amounting to 25.4 ± 1.0 years (mean ± SD). HU was defined by the Uric Acid Right for Heart Health (URRAh) cutoff (5.1 for females and 5.6 mg/dl for males). Mean SUA values during follow-up increased from 4.7 ± 1.1 to 5.0 ± 1.2 mg/dl (P<0.001), the average SUA elevation amounting to of 0.3 ± 1.1 mg/dl 26.7 % of the subjects displayed HU at the follow-up. This was associated at the multivariable analysis with female gender, office, home and 24-h blood pressure, diuretic treatment, serum triglycerides and baseline SUA, as well as the increase in waist circumference and the reduction in renal function.

CONCLUSION

The present study provides longitudinal evidence that in the general population during a 25 year follow-up there is a progressive increase in SUA and HU development. Baseline SUA represents the most important factor associated with these modifications. Gender, renal dysfunction, triglycerides, obesity, diuretic treatment and blood pressure represent other variables capable to predict future occurrence of HU.

Prognostic impacts of serum uric acid levels in patients with chronic heart failure: insights from the CHART-2 study

AIMS

Prognostic impacts of serum uric acid (UA) levels in patients with chronic heart failure (CHF) remain inconclusive, especially for the whole range of serum UA levels.

METHODS AND RESULTS

In the Chronic Heart Failure Registry and Analysis in the Tohoku District-2 (CHART-2) study, we enrolled 4652 consecutive patients with CHF and classified them into four groups based on baseline serum UA levels by the Classification and Regression Tree: G1 (<3.8 mg/dL, N = 313), G2 (3.8-7.1 mg/dL, N = 3070), G3 (7.2-9.2 mg/dL, N = 1018), and G4 (>9.2 mg/dL, N = 251). Mean age was 71 ± 12, 69 ± 12, 68 ± 13, and 69 ± 15 years in G1, G2, G3, and G4, respectively (P < 0.001). During the median follow-up of 6.3 years, in G1, G2, G3, and G4, 111 (35%), 905 (29%), 370 (36%), and 139 (55%) patients died and 79 (25%), 729 (24%), 300 (29%), and 115 (46%) experienced heart failure hospitalization, respectively (both P < 0.001). G1 was characterized by a significantly high prevalence of women as compared with G2, G3, and G4 (59%, 32%, 24%, and 23%, respectively). Serum creatinine levels (0.8 ± 0.4, 0.9 ± 0.4, 1.2 ± 0.6, and 1.4 ± 0.8 mg/dL, respectively), prevalence of atrial fibrillation (34%, 39%, 45%, and 50%, respectively), and diuretics use (36%, 45%, 67%, and 89%, respectively) increased from G1, G2, G3 to G4 (all P < 0.001), while left ventricular ejection fraction decreased from G1, G2, G3 to G4 (59 ± 15, 58 ± 15, 54 ± 15, and 52 ± 17%, respectively, P < 0.001). Multivariable Cox proportional hazards models showed that, as compared with G2, both G1 and G4 had increased incidence of all-cause death [adjusted hazard ratio (aHR) 1.34, 95% confidence interval (CI) 1.08-1.67, P = 0.009; aHR 1.28, 95% CI 1.02-1.61, P = 0.037, respectively] and heart failure admission (aHR 1.39, 95% CI 1.09-1.78, P = 0.008 and aHR 1.35, 95% CI, 1.06-1.71, P = 0.014, respectively). This U-shaped relationship was evident in the elderly patients. Furthermore, abnormal transitions to either higher or lower levels of serum UA from G2 were associated with increased mortality (aHR 1.29, 95% CI 1.06-1.57, P = 0.012; aHR 1.57, 95% CI 1.12-2.20, P = 0.009).

CONCLUSIONS

These results demonstrate that serum UA levels have the U-shaped prognostic effects and abnormal transitions to either higher or lower levels are associated with poor prognosis in the elderly patients with CHF.

Serum uric acid level and the incidence of metabolic syndrome in middle-aged Korean men: a 5-year follow-up study

Objectives:

Elevated serum uric acid (UA) has been known to be associated with the prevalence of metabolic syndrome (MetS). However, no prospective studies have examined whether serum UA levels are actually associated with the development of MetS. We performed a prospective study to evaluate the longitudinal effects of baseline serum UA levels on the development of MetS.

Methods:

A MetS-free cohort of 14 906 healthy Korean men, who participated in a medical check-up program in 2005, was followed until 2010. MetS was defined according to the Joint Interim Statement of the International Diabetes Federation Task Force on Epidemiology and Prevention. Cox proportional hazards models were performed.

Results:

During 52 466.1 person-years of follow-up, 2428 incident cases of MetS developed between 2006 and 2010. After adjusting for multiple covariates, the hazard ratios (95% confidence intervals) for incident MetS for the second, the third, and the fourth quartile to the first quartile of serum UA levels were 1.09 (0.92-1.29), 1.22 (1.04-1.44), and 1.48 (1.26-1.73), respectively (p for trend <0.001). These associations were also significant in the clinically relevant subgroup analyses.

Conclusions:

Elevated serum UA levels were independently associated with future development of MetS in Korean men during the 5-year follow-up period.

Dietary, anthropometric, and biochemical determinants of uric acid in free-living adults

BACKGROUND

High plasma uric acid (UA) is a prerequisite for gout and is also associated with the metabolic syndrome and its components and consequently risk factors for cardiovascular diseases. Hence, the management of UA serum concentrations would be essential for the treatment and/or prevention of human diseases and, to that end, it is necessary to know what the main factors that control the uricemia increase. The aim of this study was to evaluate the main factors associated with higher uricemia values analyzing diet, body composition and biochemical markers.

METHODS

415 both gender individuals aged 21 to 82 years who participated in a lifestyle modification project were studied. Anthropometric evaluation consisted of weight and height measurements with later BMI estimation. Waist circumference was also measured. The muscle mass (Muscle Mass Index - MMI) and fat percentage were measured by bioimpedance. Dietary intake was estimated by 24-hour recalls with later quantification of the servings on the Brazilian food pyramid and the Healthy Eating Index. Uric acid, glucose, triglycerides (TG), total cholesterol, urea, creatinine, gamma-GT, albumin and calcium and HDL-c were quantified in serum by the dry-chemistry method. LDL-c was estimated by the Friedewald equation and ultrasensitive C-reactive protein (CRP) by the immunochemiluminiscence method. Statistical analysis was performed by the SAS software package, version 9.1. Linear regression (odds ratio) was performed with a 95% confidence interval (CI) in order to observe the odds ratio for presenting UA above the last quartile (♂UA > 6.5 mg/dL and ♀ UA > 5 mg/dL). The level of significance adopted was lower than 5%.

RESULTS

Individuals with BMI ≥ 25 kg/m2 OR = 2.28(1.13-4.6) and lower MMI OR = 13.4 (5.21-34.56) showed greater chances of high UA levels even after all adjustments (gender, age, CRP, gamma-gt, LDL, creatinine, urea, albumin, HDL-c, TG, arterial hypertension and glucose). As regards biochemical markers, higher triglycerides OR = 2.76 (1.55-4.90), US-CRP OR = 2.77 (1.07-7.21) and urea OR = 2.53 (1.19-5.41) were associated with greater chances of high UA (adjusted for gender, age, BMI, waist circumference, MMI, glomerular filtration rate, and MS). No association was found between diet and UA.

CONCLUSIONS

The main factors associated with UA increase were altered BMI (overweight and obesity), muscle hypotrophy (MMI), higher levels of urea, triglycerides, and CRP. No dietary components were found among uricemia predictors.

G109T polymorphism of SLC22A12 gene is associated with serum uric acid level, but not with metabolic syndrome

SLC22A12 gene, encoding urate transport 1, has been known to be responsible to urate metabolism. This study sought to determine the association between the novel G109T polymorphism in SLC22A12 with serum uric acid and the development of metabolic syndrome in Korean male subjects. A total of 132 healthy male subjects were enrolled in this study. Metabolic syndrome was determined using the modified guidelines for metabolic syndrome proposed by the National Cholesterol Education Program's Third Adult Treatment Panel. Genotyping for the SLC22A12 gene was assessed using denaturing high-performance liquid chromatography analysis. Serum uric acid and fractional excretion of uric acid (FEUA) from blood and urine samples were measured. Frequencies of the 109GG, 109GT, and 109TT genotypes were 57.6, 38.6, and 3.8%, respectively. Serum uric acid levels and FEUAs were significantly different among the three genotypes of the G109T polymorphism (P = 0.035 and P = 0.033, respectively). In addition, subjects of genotypes with the T allele had lower uric acid levels and higher FEUAs compared to those with the 109GG genotype (P = 0.007 and P = 0.031, respectively). The G109T polymorphism of the SLC22A12 gene has no association with metabolic syndrome. However, a number of metabolic syndrome components were related to serum uric acid level (r = 0.285, P = 0.001) and also significantly different between genotype with and without T allele (P = 0.008). The novel G109T polymorphism of the SLC22A12 gene is related to serum uric acid level, but not to the development of metabolic syndrome.

Changes in waist circumference and body mass index in relation to changes in serum uric acid in Japanese individuals

OBJECTIVE

Studies have shown that obesity is associated with an increase in serum uric acid; and few data are available on the relationship between changes in measures of obesity and changes in uric acid concentrations. We investigated the relationship among percentage changes in waist circumference (%dWC), body mass index (%dBMI), and serum uric acid (%dUA).

METHODS

The data of 3153 individuals [1968 men, 1185 women (536 premenopausal, 649 postmenopausal)] who underwent general health screening over a 2-year period and were not taking antihyperuricemic medication were analyzed.

RESULTS

Stepwise multiple regression analysis showed that %dBMI was associated positively with %dUA in postmenopausal women and men, and the association retained statistical significance after adjustment for changes in blood pressure and in renal function. Association between %dBMI and %dUA was not significant in premenopausal women. In men, %dWC was a predicting factor for %dUA, although it did not remain significant when %dBMI was used as a covariate in the statistical model. Multivariate logistic regression analysis showed that the odds ratio of the association between the lowest %dBMI quartile (%dBMI < -1.86) and the lowest %dUA quartile (%dUA < -7.41) was 2.04 (95% CI 1.35-3.07) in postmenopausal women and 1.46 (95% CI 1.14-1.86) in men.

CONCLUSION

Weight loss may represent an effective nonmedical strategy for reducing serum UA levels, especially in postmenopausal women and men.