Atherosclerosis and urate metabolism

Urate-Lowering Therapy May Prevent the Development of Coronary Artery Disease in Patients With Gout

Substantial evidence has demonstrated a close relationship between hyperuricemia and cardiovascular (CV) diseases, but few studies have explored the possibility of using urate-lowering therapy (ULT) to attenuate the development of CV diseases. To compare the risks of incident coronary artery disease (CAD), stroke, and heart failure (HF) between ULT users and non-users in patients with gout, we conducted a retrospective cohort study from the population-based National Health Insurance Research Database in Taiwan. In total, 4,072 patients with gout were included between 2000 and 2012. The overall incident rates of CAD, stroke, and HF were compared between 2,036 ULT users and 2,036 matched non-users. The incident rates of incident CAD were 1.3 and 1.7 per 100 person-years for ULT users and non-users. ULT users had a lower adjusted hazard ratio (aHR) for CAD [aHR: 0.7, 95% confidence interval (CI): 0.55–0.89] compared with non-users. ULT users also had a lower aHR for incident stroke (aHR: 0.68, 95% CI: 0.5–0.92) compared with non-users. ULT had a neutral effect on the risk of incident HF (aHR: 0.92, 95% CI: 0.58–1.45). Among the urate-lowering therapy, subgroup analyses indicated that uricosuric agents had a significant effect on the prevention of CAD and stroke development; and the protection against the development of CAD by uricosuric agents appeared to have a dose-response trend. Our study demonstrated that ULT associated with lower risks of incident CAD and stroke. We recommend that patients with gout receive ULT to lower the burden of CV diseases.

Asymptomatic hyperuricemia and coronary flow reserve in patients with metabolic syndrome

Background

Patients with metabolic syndrome (MetS) are at increased risk of asymptomatic hyperuricemia (i.e., elevated serum uric acid (SUA) level without gout) and cardiovascular disease. We conducted a cross-sectional study to examine associations between SUA levels and coronary flow reserve and urate deposits in carotid arteries in patients with asymptomatic hyperuricemia and MetS.

Methods

Adults aged ≥40 years with MetS and SUA levels ≥6.5 mg/dl, but no gout, were eligible. Using a stress myocardial perfusion positron emission tomography (PET), we assessed myocardial blood flow (MBF) at rest and stress and calculated coronary flow reserve (CFR). CFR < 2.0 is considered abnormal and associated with increased cardiovascular risk. We also measured insulin resistance by homeostatic model assessment (HOMA-IR) method and urate deposits using dual-energy CT (DECT) of the neck for the carotid arteries.

Results

Forty-four patients with the median age of 63.5 years underwent a blood test, cardiac PET and neck DECT scans. Median (IQR) SUA was 7.8 (7.1-8.4) mg/dL. The median (IQR) CFR was abnormally low at 1.9 (1.7-2.4) and the median (IQR) stress MBF was 1.7 (1.3-2.2) ml/min/g. None had urate deposits in the carotid arteries detected by DECT. In multivariable linear regression analyses, SUA had no association with CFR (β = - 0.12, p = 0.78) or stress MBF (β = - 0.52, p = 0.28). Among non-diabetic patients (n = 25), SUA was not associated with HOMA-IR (β = 2.08, p = 0.10).

Conclusions

Among MetS patients with asymptomatic hyperuricemia, we found no relationship between SUA and CFR, stress MBF, and insulin resistance. No patients had any DECT detectable subclinical urate deposition in the carotid arteries.

Association of diabetes mellitus with decline in ankle-brachial index among patients on hemodialysis: A 6-year follow-up study

Peripheral artery occlusive disease is common among diabetes mellitus (DM) and end-stage renal disease patients, and tends to progress faster and lead to worse outcomes. This study compared the association of DM with the decline in ankle-brachial index (ABI) among patients on hemodialysis (HD). This was a longitudinal analysis of ABI in HD patients from 2009 to 2015. Medical records and yearly ABI values were obtained. A longitudinal mixed-model analysis was used to evaluate ABI changing trends while accounting for within-patients correlation. There were 296 patients on HD in the period of 2009-2015. In a 6-year follow-up, those with DM had a more rapid ABI decline compared to non-DM patients (slopes: -0.014 vs. 0.010 per year, interaction p < 0.001). In DM patients, female sex, high pulse pressure, high triglyceride, low creatinine, and high uric acid were associated with a decrease in ABI. In non-DM patients, old age, high pulse pressure, high low-density lipoprotein cholesterol, and high uric acid were associated with a decreased in ABI. There were 49.6% of patients with a normal ABI experienced a decrease at least 0.1 of ABI from baseline, and 35.3% had a final ABI < 0.9 in patients with a baseline ABI ≥ 0.9 (n = 232). In this study, DM patients on HD tend to develop a more rapid decline in ABI than non-DM patients on HD. Age, sex, pulse pressure, lipid profile, creatinine, and uric acid are associated with a decreased in ABI.

Association of Far-Infrared Radiation Therapy and Ankle-Brachial Index of Patients on Hemodialysis with Peripheral Artery Occlusive Disease

Background and Aim: The ankle-brachial index (ABI) is recognized to be a good marker for atherosclerosis, and is useful in the diagnosis of peripheral artery occlusive disease (PAOD) which is prevalent among patients on hemodialysis (HD). Methods: This randomized trial aimed to evaluate the effect of far-infrared radiation (FIR) therapy on ABI in HD patients with PAOD. PAOD was defined as patients with ABI < 0.95. One hundred and eight HD patients were enrolled, including 50 in the control group and 58 in the FIR group. A WS TY101 FIR emitter was applied for 40 minutes during each HD session, three times per week for six months. The ABI was measured before and after the FIR therapy. Results: Regardless of FIR therapy, the bilateral ABI decreased (in the FIR group, left: 0.88±0.22 to 0.85±0.24, p = 0.188; right: 0.92±0.20 to 0.90±0.23, p = 0.372; in control group, left: 0.91±0.23 to 0.88±0.21, p = 0144; right: 0.93±0.17 to 0.89±0.21, p = 0.082). Multivariate logistic analysis of the FIR group revealed that high uric acid (odds ratio [OR]: 2.335; 95% confidence interval [CI]: 1.117-4.882; p=0.024) and aspirin use (OR: 16.463; 95% CI: 1.787-151.638; p=0.013) were independently associated with increased bilateral ABI after FIR therapy. Conclusions: This study demonstrates that ABI is not increased after FIR therapy in HD patients with PAOD. However, in the FIR group, patients with higher uric acid level or those who used aspirin have increased bilateral ABI after FIR therapy.

Association of uric acid with mortality in patients with stable coronary artery disease

OBJECTIVE

The association between uric acid and cardiovascular disease is poorly studied. We undertook this study to assess whether uric acid level predicts clinical outcome in patients with stable coronary artery disease (CAD) treated with percutaneous coronary intervention (PCI).

MATERIALS/METHODS

This study included 8149 patients with stable CAD who underwent PCI. Uric acid was measured before angiography. The primary end point was 1-year mortality. Quartiles of quartiles of uric acid were: 1.49 to <5.49 mg/dl (1st quartile; n=2032 patients), 5.49 to <6.40 mg/dl (2nd quartile; n=1981 patients), 6.40 to <7.50 mg/dl (3rd quartile; n=2093 patients) and 7.50 to 21.90 mg/dl (4th quartile; n=2043 patients).

RESULTS

There were 196 deaths during the 1-year follow-up. The numbers of deaths (Kaplan-Meier estimates) according to uric acid quartiles were: 35 deaths (1.8%) in the 1st quartile, 30 deaths (1.6%) in the 2nd quartile, 45 deaths (2.2%) in the 3rd quartile and 86 deaths (4.3%) in the 4th quartile (unadjusted hazard ratio [HR]=1.60, 95% confidence interval [CI] 1.38-1.86, P<0.001 for each standard deviation [SD] increase in the logarithmic scale). After adjustment for traditional cardiovascular risk factors, renal function and inflammatory status, the association between uric acid and 1-year mortality remained significant (adjusted HR=1.26, 95% CI 1.07-1.48; P=0.005 for each standard deviation increase in the logarithmic scale). Uric acid improved predictivity of the multivariable model regarding mortality (P=0.040).

CONCLUSIONS

Elevated level of uric acid is an independent predictor of 1-year mortality in patients with stable CAD treated with PCI.

Metabolic syndrome and dietary components are associated with coronary artery disease risk score in free-living adults: a cross-sectional study

BACKGROUND

Coronary artery disease (CAD) is among the main causes of death in developed countries, and diet and lifestyle can influence CAD incidence.

OBJECTIVE

To evaluate the association of coronary artery disease risk score with dietary, anthropometric and biochemical components in adults clinically selected for a lifestyle modification program.

METHODS

362 adults (96 men, 266 women, 53.9 ± 9.4 years) fulfilled the inclusion criteria by presenting all the required data. The Framingham score was calculated and the IV Brazilian Guideline on Dyslipidemia and Prevention of Atherosclerosis was adopted for classification of the CAD risks. Anthropometric assessments included waist circumference (WC), body fat and calculated BMI (kg/m2) and muscle-mass index (MMI kg/m2). Dietary intake was estimated through 24 h dietary recall. Fasting blood was used for biochemical analysis. Metabolic Syndrome (MS) was diagnosed using NCEP-ATPIII (2001) criteria. Logistic regression was used to determine the odds of CAD risks according to the altered components of MS, dietary, anthropometric, and biochemical components.

RESULTS

For a sample with a BMI 28.5 ± 5.0 kg/m2 the association with lower risk (<10% CAD) were lower age (<60 years old), and plasma values of uric acid. The presence of MS within low, intermediary, and high CAD risk categories was 30.8%, 55.5%, and 69.8%, respectively. The independent risk factors associated with CAD risk score was MS and uric acid, and the protective factors were recommended intake of saturated fat and fiber and muscle mass index.

CONCLUSION

Recommended intake of saturated fat and dietary fiber, together with proper muscle mass, are inversely associated with CAD risk score. On the other hand, the presence of MS and high plasma uric acid are associated with CAD risk score.

Clinical value of serum uric Acid in patients with suspected coronary artery disease

BACKGROUND/AIMS

Although increased serum uric acid (SUA) concentrations are commonly encountered in patients with risk factors for coronary artery disease (CAD), the clinical value of SUA has not been established.

METHODS

The study group comprised 687 consecutive patients with suspected CAD who had undergone coronary angiography. CAD was defined as stenosis > or = 50% of the luminal diameter. CAD severity was expressed as 1-, 2-, or 3-vessel disease. Metabolic syndrome (MS) was defined according to National Cholesterol Education Program-Adult Treatment Panel III (NCEP-ATP III) criteria, and aortofemoral pulse wave velocity (PWV) was obtained by arterial catheterization invasively.

RESULTS

In total, 395 patients had CAD. SUA was higher in patients with CAD as compared to those without CAD (5.5 +/- 1.0 vs. 5.2 +/- 1.0 mg/dL, p = 0.004). In addition, SUA was significantly associated with the severity of CAD (p = 0.002). However, after adjusting for significant confounding factors including age, diabetes, smoking, cholesterol, MS, and PWV, SUA was not an independent risk factor for CAD (p = 0.151). Based on a subgroup analysis, SUA was more closely associated with CAD in women than in men, and in the highest quartile (> or = 6.4 mg/dL) than in the first quartile (< 4.8 mg/dL); however, these results were not significant (p = 0.062, p = 0.075, respectively). In a multivariate regression analysis, the most important determinant of SUA was MS (i.e., insulin resistance syndrome), which is strongly associated with CAD.

CONCLUSIONS

In patients with suspected CAD, SUA was not an independent risk factor for CAD and may be merely a marker of insulin resistance.

Uric acid levels are associated with all-cause and cardiovascular disease mortality independent of systemic inflammation in men from the general population: the MONICA/KORA cohort study

OBJECTIVE

The purpose of this study was to assess whether increasing serum uric acid (UA) levels are related to cardiovascular disease (CVD) mortality, all-cause mortality, and incident (fatal and nonfatal) myocardial infarction (MI) in men from the general population taking into account C-reactive protein (CRP), a sensitive marker of systemic inflammation.

METHODS AND RESULTS

The study was based on 3604 men (45 to 74 years of age) who participated in 1 of the 3 MONICA Augsburg surveys between 1984 and 1995. All participants were prospectively followed within the framework of the Cooperative Health Research in the Region of Augsburg (KORA). Up to December 31, 2002, there occurred 809 total deaths, 359 CVD deaths, and 297 incident MIs. In a Cox model, comparing extreme quartiles of the UA distribution, the hazard ratio for CVD mortality was 1.44 (95% confidence interval [CI] 1.04 to 2.0), and for all-cause mortality it was 1.40 (95% CI 1.13 to 1.74) after adjustment for conventional cardiovascular risk factors, CRP, and diuretic intake. However, UA was not associated with incident MI after multivariable adjustment.

CONCLUSIONS

High UA levels were independently associated with CVD mortality as well as all-cause mortality but not with incident MI in middle-aged men from the general population.

Serum uric acid level and risk for peripheral arterial disease: analysis of data from the multiple risk factor intervention trial

Although several studies report an association between hyperuricemia and coronary artery disease, little is known about the effect of hyperuricemia and gout on the risk of peripheral arterial disease (PAD). Data on 283 incident clinical cases of PAD during a randomized controlled trial of multiple cardiovascular risk factor intervention are evaluated. The serum uric acid levels among these individuals are compared with those of individuals who did not develop PAD during the study period. Multivariate logistic regression analyses measure the risk of developing PAD associated with higher levels of serum uric acid after adjusting for the effect of traditional vascular risk factors. Age and smoking are independently associated with development of PAD, with odds ratios of 1.08 (95% confidence interval [CI], 1.06-1.09) and 3.83 (95% CI, 2.49-5.91) per year, respectively. Hyperuricemia (serum uric acid level, >7.0 mg/dL) is an independent risk factor, with an odds ratio of 1.23, but the confidence interval of the estimate is wide (95% CI, 0.98-1.54). In this multivariate model, a history of gout was associated with an odds ratio of 1.33 (95% CI, 1.07-1.66). Serum uric acid level is independently associated with a higher (but statistically nonsignificant) risk of PAD. A history of gouty arthritis is an independent and statistically significant predictor of incidence of PAD even after adjustment for the effect of underlying hyperuricemia.

Serum uric acid and cardiovascular disease: recent developments, and where do they leave us?

The relationship between serum uric acid (SUA) and cardiovascular disease has been controversial. Here we review recent literature assessing whether hyperuricemia is an independent risk factor for adverse cardiovascular outcomes. Studies from the past 6 years evaluating the association of SUA with cardiovascular disease were identified through MEDLINE, EMBASE, and Cochrane library searches, bibliography cross-referencing, and review articles. Twenty-one cohort studies in healthy and high-risk patients with cardiovascular disease were identified and reviewed. In studies of high-risk patients, in which more overall events were recorded, 10 of 11 studies were supportive of an independent association. In 10 studies of healthy patients, 6 suggested an independent association of SUA with adverse cardiovascular outcomes. Increasing SUA is likely an independent risk factor for cardiovascular disease in high-risk individuals. However, the magnitude of excess risk attributable to high SUA is likely to be small in healthy individuals. Trials of SUA-lowering therapy in hyperuricemic patients evaluating the effect on cardiovascular outcomes are justified in high-risk patients.

Serum uric acid and risk of death from cancer, cardiovascular disease or all causes in men

OBJECTIVE

Although many epidemiological studies have suggested that increased serum uric acid levels are a risk factor for mortality, this relationship remains uncertain. This cohort study examined the effects of serum uric acid level on death from cancer, atherosclerotic cardiovascular disease (ASCVD) or all causes in men.

METHOD

A 9-year, prospective cohort study was carried out with 22698 Korean men, aged 30 to 77 years, who received health insurance from the National Health Insurance Corporation and who underwent biennial, secondary medical evaluations in 1992-1996. The main outcome measures were death from cancer, ASCVD or all causes, compared by quintiles of serum uric acid level. At baseline, the mean (SD) level of serum uric acid was 354.4 (98.1) micromol/l.

RESULTS

During 199746 person-years of follow-up, there were 387 cancer deaths, 323 ASCVD (99 ischaemic heart disease, 192 stroke) deaths and 1625 all-cause deaths. In multivariate Cox proportional hazards models, having controlled for age, current smoking, diabetes, hypertension and hypercholesterolaemia, uric acid levels were not associated with mortality from cancer, ASCVD or all causes. However, for those with diabetes, uric acid levels were associated with mortality from all causes even after full adjustment of the covariates. When the interaction term was included in the multivariate model, there was significant interactive effect of uric acid with diabetes (RR=1.26, 95% confidence interval 1.02-1.55) on the risk of all cause of death, whereas the effects of uric acid itself did not attain significance.

CONCLUSION

These findings indicate that uric acid level is not an independent risk factor for death from cancer, ASCVD or all causes.

Effect of statins versus untreated dyslipidemia on serum uric acid levels in patients with coronary heart disease: a subgroup analysis of the GREek Atorvastatin and Coronary-heart-disease Evaluation (GREACE) study

BACKGROUND

Little is known about the effect of dyslipidemia on serum uric acid (SUA) levels, and less is known about the effect of statin treatment on them. The GREek Atorvastatin and Coronary-heart-disease Evaluation study suggested that a mean atorvastatin dose of 24 mg/d achieves the National Cholesterol Educational Program treatment goals and significantly reduces morbidity and mortality in patients with coronary heart disease (CHD) in comparison to the usual care. Here, we report the time course of SUA levels in usual-care patients undertreated for their dyslipidemia (12% were administered statins) in comparison to structured-care patients treated with atorvastatin in the vast majority (98%).

METHODS

Mean on-study SUA levels (up to 48 months) were compared with those at baseline by using analyses of variance to assess differences over time within and between treatment groups. Cox multivariate analysis was used to investigate whether changes in SUA levels during the study were clinically relevant.

RESULTS

All patients had normal renal function at baseline; serum creatinine (SCr) levels less than 1.3 mg/dL (<115 micromol/L) and moderately elevated SUA levels (mean, 7.1 +/- 0.9 [SD] mg/dL [425 +/- 52 micromol/L]; upper normal limit, 7.0 mg/dL [415 micromol/L]). Usual-care patients (n = 800) showed an increase in SUA levels by 3.3% ( P < 0.0001). Structured-care patients (n = 800) had an 8.2% reduction in SUA levels ( P < 0.0001). In all patients not administered diuretics (n = 1,407), SUA level changes showed a positive correlation with changes in SCr levels ( r = 0.82; P < 0.0001) and an inverse correlation with estimated glomerular filtration rate ( r = -0.77; P < 0.0001). After adjustment for 19 predictors of all CHD-related events, Cox multivariate analysis involving backward stepwise logistic regression showed a hazard ratio (HR) of 0.89 (95% confidence interval [CI], 0.78 to 0.96; P = 0.03) with every 0.5-mg (30-micromol/L) reduction in SUA level, an HR of 0.76 (95% CI, 0.62 to 0.89; P = 0.001) with every 1-mg (60-micromol/L) reduction, an HR of 1.14 (95% CI, 1.03 to 1.27; P = 0.02) with every 0.5-mg increase, and an HR of 1.29 (95% CI, 1.17 to 1.43; P = 0.001) with every 1-mg increase in SUA levels.

CONCLUSION

Data suggest that SUA level is an independent predictor of CHD recurrent events. Atorvastatin treatment significantly reduces SUA levels in patients with CHD, thus offsetting an additional factor associated with CHD risk.

Serum uric acid as an independent predictor of mortality in patients with angiographically proven coronary artery disease

It is a matter of controversy as to whether uric acid is an independent predictor of mortality in patients with coronary artery disease (CAD) or whether it represents only an indirect marker of adverse outcome by reflecting the association between uric acid and other cardiovascular risk factors. Therefore, we studied the influence of uric acid levels on mortality in patients with CAD. In 1,017 patients with angiographically proven CAD, classic risk factors and uric acid levels were determined at enrollment. A follow-up over a median of 2.2 years (maximum 3.1) was performed. Death from all causes was defined as an end point of the study. In CAD patients with uric acid levels <303 micromol/L (5.1 mg/dl) (lowest quartile) compared with those with uric acid levels >433 micromol/L (7.1 mg/dl) (highest quartile), the mortality rate increased from 3.4% to 17.1% (fivefold increase). After adjustment for age, both sexes demonstrated an increased risk for death with increasing uric acid levels (female patients: hazard ratio [HR] 1.30, 95% confidence intervals [CI] 1.14 to 1.49, p < or = 0.001; male patients: HR 1.39 [95% CI 1.21 to 1.59], p < or = 0.001). In multivariate Cox regression analysis performed with 12 variables that influence overall mortality-including diuretic use-elevated levels of uric acid demonstrated an independent, significant positive relation to overall mortality (HR 1.23 [95% CI 1.11 to 1.36], p <0.001) in patients with CAD. Thus, uric acid is an independent predictor of mortality in patients with CAD.

Serum uric acid and risk of coronary heart disease: Atherosclerosis Risk in Communities (ARIC) Study

PURPOSE

Approximately half of previous studies on serum uric acid have reported it to be an independent risk factor for coronary heart disease (CHD). We tested this hypothesis in the Atherosclerosis Risk in Communities (ARIC) Study.

METHODS

A total of 13,504 healthy middle-aged men and women were followed prospectively for up to eight years. We identified 128 fatal and nonfatal CHD events in women and 264 in men.

RESULTS

The age-, race-, and ARIC field center-adjusted relative risk of CHD for sex-specific quartiles of serum uric acid were 1.0, 1.39, 1.08, and 2.35 in women (p for trend = 0.009) and 1.0, 1.03, 0.89, and 1.21 in men (p for trend = 0.44), respectively. However, serum uric acid was correlated positively with many risk factors, and after multivariable adjustment, there was little evidence of an association of uric acid with CHD in either sex.

CONCLUSIONS

Our results are not consistent with serum uric acid being an independent risk factor for CHD.

Uric acid and serum antioxidant capacity: a reaction to atherosclerosis?

BACKGROUND

the evidence of a potential beneficial role of antioxidants in preventing atherosclerotic disease is not entirely consistent.

OBJECTIVE

to assess the longitudinal association of serum total antioxidant capacity and serum antioxidants with the presence of subclinical carotid atherosclerosis.

METHODS

Prospective case-control study nested within an historical cohort. Cases were 150 individuals with elevated carotid intimal-medial thickness measured by B-mode ultrasound at the first two examinations of the Atherosclerosis Risk in Communities Study (1987-92). Controls were 150 age-gender-matched individuals with low carotid intimal-medial thickness. Serum antioxidant vitamins, uric acid, and serum total antioxidant capacity were measured in frozen serum samples collected from the same individuals in 1974 (13-15 years prior to the determination of case-control status).

RESULTS

Compared to controls, atherosclerosis cases had significantly higher levels of serum total antioxidant capacity in 1974 than controls. This difference was almost entirely explained by increased serum concentration of uric acid in cases. In contrast with cross-sectional results, uric acid serum concentration in 1974, was significantly higher in cases than in controls, even after adjusting for the main cardiovascular risk factors. Cases had significantly lower levels of alpha-carotene in the 1974 sera than controls, but no other differences in serum antioxidant vitamin concentrations were observed.

CONCLUSIONS

The higher serum uric acid concentration seemed associated with elevated total serum antioxidant capacity among individuals with atherosclerosis. This finding is consistent with experimental evidence suggesting that hyperuricemia may be a compensatory mechanism to counteract oxidative damage related to atherosclerosis and aging in humans.

Correlates of uric acid and its association with asymptomatic carotid atherosclerosis: the ARIC Study. Atherosclerosis Risk in Communities

The correlates of serum uric acid and the association of uric acid with carotid intimal-medial thickness (an early measure of atherosclerosis) were investigated in participants of the baseline examination of the Atherosclerosis Risk in Communities (ARIC) Study. The study sample included 6522 women (74% white) and 4966 men (79% white) who were aged 45 to 64 years at baseline (1986-1989). Those with prevalent coronary heart disease or previous stroke and those taking uricosuric medication were excluded. The mean (SD) uric acid concentration was 5.9 (1.5) mg/dL. It was highest among black men 45-54 years old (6.9 [1.5] mg/dL), and lowest in white women aged 45-54 years old (5.0 [1.2] mg/dL). The uric acid level was positively correlated in both sexes with a variety of health-related factors, most notably body mass index, creatinine, triglycerides, diuretic use, alcohol intake, hypertension, diabetes, and insulin levels. In a linear regression model adjusting for age and ARIC center, the level of uric acid was directly and significantly associated with B-mode ultrasound carotid intimal-medial thickness in women and white men (but not in black men). However, when known risk factors for atherosclerotic disease and relevant behavioral and biological correlates of uric acid were controlled for in multivariate analysis, the association of uric acid with this early measure of atherosclerosis became negligible in white women and much weaker and not statistically significant in black women and white men. Thus, uric acid itself may not be a risk factor for atherosclerosis. Future analysis of cardiovascular events in the ARIC Study will further elucidate the role of uric acid in atherosclerotic disease.

High uric acid: a metabolic marker of coronary heart disease among alcohol abstainers

The association between serum uric acid level and risk of coronary heart disease (CHD) over 21 years was investigated among 6411 middle-aged Japanese-American men who were participants in the Honolulu Heart Program. In an age-stratified Cox regression model, high serum uric acid (quartile 4 [>6.7 mg/dl], relative to quartile 1 [<5.0 mg/dl]) was a significant predictor of definite CHD (RR = 1.33; 95% confidence interval = 1.08-1.63; p = 0.006). However, when adjustment for confounders (body mass index, heavy alcohol consumption, triglycerides, diastolic blood pressure, blood glucose, and the ratio of animal to vegetable protein) was made, the association of high uric acid with coronary events was substantially reduced and became nonsignificant (RR = 1.14; 95% confidence interval = 0.92-1.42; p = 0.21). There was a significant interaction between serum uric acid and drinking status (P = 0.03). Thus, the risk of definite CHD associated with high urate levels (quartile 4), relative to low levels (quartile 1), was elevated in the abstainers (RR = 1.40; 95% confidence interval = 1.01-1.93; p = 0.02), but not in light and moderate drinkers (RR = 1.1 1; 95% confidence interval = 0.79-1.55; p = 0.58) or among the heavy drinkers (>40 ml of ethanol/day; RR = 0.57; 95% confidence interval = 0.27-1.21; p = 0.08). It is concluded that elevated uric acid may be associated with higher CHD among alcohol abstainers. Whether raised urate is an etiological factor for CHD or a manifestation of existing arterial disease in nondrinkers deserves further investigation.

Autosomal dominant transmission of gouty arthritis with renal disease in a large Japanese family

Six generations of a Japanese family had gouty arthritis and progressive nephropathy. Data on nine of 51 women (18%) and 15 of 66 men (23%) with either asymptomatic hyperuricaemia, gouty arthritis, or renal insufficiency were obtained. Renal function in four men and one woman with hyperuricaemia or gouty arthritis was also examined. Urinary excretion of uric acid was decreased in all subjects examined, including the young. Erythrocyte phosphoribosylpyrophosphate synthetase and hypoxanthine-guanine phosphoribosyltransferase activities determined in 10 patients were normal. Some patients had been treated with allopurinol to reduce serum uric acid concentrations, but the treatment did not prevent progression of renal impairment. Transmission of the disease in this large family is considered to be autosomal dominant. The data suggest that the disease in this family is the same entity as that described by other workers--that is, familial urate nephropathy. As far as is known this is the largest family with this disease so far reported.

Therapeutics of hyperuricaemia and gout

Environmental factors, including diet, fluid intake and alcohol consumption, often contribute significantly to the development of hyperuricaemia. The contribution of these factors, together with body size and the renal excretory capacity for urate, can be assessed on the basis of the clinical history and examination, together with simple investigations. These include the measurement of both serum levels of urate and the urinary excretion of urate, and the effect of purine restriction on these measurements. Recognition of causative factors provides the potential for their correction. Should gout develop, serum urate levels must be reduced to normal. This usually, but not invariably, necessitates prolonged drug treatment. The major problem in maintaining serum urate levels within the normal range is that this depends upon the cooperation of the patient. Acute gout needs to be managed on its own merits, irrespective of the use of drugs which alter the serum urate concentration. Prophylactic therapy with colchicine reduces the frequency of acute attacks of gout, whether the serum urate level is normal or elevated.