Gout and hyperlipidaemia

Uricosuric medications for chronic gout

BACKGROUND

Uricosuric agents have long been used in the treatment of gout but there is little evidence regarding their benefit and safety in this condition.

OBJECTIVES

To assess the benefits and harms of uricosuric medications in the treatment of chronic gout.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL, Issue 4, 2013), Ovid MEDLINE and Ovid EMBASE for studies to the 13 May 2013. We also searched the World Health Organization Clinical Trials Registry, ClinicalTrials.gov and the 2011 to 2012 American College of Rheumatology and European League against Rheumatism abstracts. WE considered black box warnings and searched drug safety databases to identify and describe rare adverse events.

SELECTION CRITERIA

We considered all randomised controlled trials (RCTs) or quasi-randomised controlled trials (controlled clinical trials (CCTs)) that compared uricosuric medications (benzbromarone, probenecid or sulphinpyrazone) alone or in combination with another therapy (placebo or other active uric acid-lowering medication, or non-pharmacological treatment) in adults with chronic gout for inclusion.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected the studies for inclusion, extracted data and performed a risk of bias assessment. Main outcomes were frequency of acute gout attacks, serum urate normalisation, study participant withdrawal due to adverse events, total adverse events, pain reduction, function and tophus regression.

MAIN RESULTS

The search identified four RCTs and one CCT that evaluated the benefit and safety of uricosurics for gout. One study (65 participants) compared benzbromarone with allopurinol for a duration of four months; one compared benzbromarone with allopurinol (36 participants) for a duration of nine to 24 months; one study (62 participants) compared benzbromarone with probenecid for two months and one study (74 participants) compared benzbromarone with probenecid. One study (37 participants) compared allopurinol with probenecid. No study was completely free from bias.Low-quality evidence from one study (55 participants) comparing benzbromarone with allopurinol indicated uncertain effects in terms of frequency of acute gout attacks (4% with benzbromarone versus 0% with allopurinol; risk ratio (RR) 3.58, 95% confidence interval (CI) 0.15 to 84.13), while moderate-quality evidence from two studies (101 participants; treated for four to nine months) indicated similar proportions of participants achieving serum urate normalisation (73.9% with benzbromarone versus 60% with allopurinol; pooled RR 1.27, 95% CI 0.90 to 1.79). Low-quality evidence indicated uncertain differences in withdrawals due to adverse events (7.1% with benzbromarone versus 6.1% with allopurinol; pooled RR 1.25, 95% CI 0.28 to 5.62), and total adverse events (20% with benzbromarone versus 6.7% with allopurinol; RR 3.00, 95% CI 0.64 to 14.16). The study did not measure pain reduction, function and tophus regression.When comparing benzbromarone with probenecid, there was moderate-quality evidence based on one study (62 participants) that participants taking benzbromarone were more likely to achieve serum urate normalisation after two months (81.5% with benzbromarone versus 57.1% with probenecid; RR 1.43, 95% CI 1.02 to 2.00). This indicated that when compared with probenecid, five participants needed to be treated with benzbromarone in order to have one additional person achieve serum urate normalisation (number needed to treat for an additional beneficial outcome (NNTB) 5). However, the second study reported no difference in the absolute decrease in serum urate between these groups after 12 weeks. Low-quality evidence from two studies (129 participants) indicated uncertain differences between treatments in the frequency of acute gout attacks (6.3% with benzbromarone versus 10.6% with probenecid; pooled RR 0.73, 95% CI 0.09 to 5.83); fewer withdrawals due to adverse events with benzbromarone (2% with benzbromarone versus 17% with probenecid; pooled RR 0.15, 95% CI 0.03 to 0.79, NNTB 7) and fewer total adverse events (21% with benzbromarone versus 47% with probenecid; pooled RR 0.43, 95% CI 0.25 to 0.74; NNTB 4). The studies did not measure pain reduction, function and tophus regression.Low-quality evidence based on one small CCT (37 participants) indicated uncertainty around the difference in the incidence of acute gout attacks between probenecid and allopurinol after 18 to 20 months' treatment (53% with probenecid versus 55% with allopurinol; RR 0.96, 95% CI 0.53 to 1.75). The study did not measure or report the proportion achieving serum urate normalisation, pain reduction, function, tophus regression, withdrawal due to adverse events and total adverse events.

AUTHORS' CONCLUSIONS

There was moderate-quality evidence that there is probably no important difference between benzbromarone and allopurinol at achieving serum urate normalisation, but that benzbromarone is probably more successful than probenecid at achieving serum urate normalisation in people with gout. There is some uncertainty around the effect estimates, based on low-quality evidence from only one or two trials, on the number of acute gout attacks, the number of withdrawals due to adverse events or the total number of participants experiencing adverse events when comparing benzbromarone with allopurinol. However, when compared with probenecid, benzbromarone resulted in fewer withdrawals due to adverse events and fewer participants experiencing adverse events. Low-quality evidence from one small study indicated uncertain effects in the incidence of acute gout attacks when comparing probenecid with allopurinol therapy. We downgraded the evidence because of a possible risk of performance and other biases and imprecision.

Effects of Uric Acid on Lipid Levels in CKD Patients in a Randomized Controlled Trial

Background

Few studies have been conducted that compared lipid levels and uric acid in CKD or End-Stage Renal Disease (ESRD) patients with most using animal models. The purpose of the study was to explore effects on lipids while controlling uric acid levels in CKD patients.

Methods

Twenty-four CKD patients (N = 24) volunteered to participate in this study. The study was conducted using a double-blind, randomized, placebo controlled experimental protocol. The experimental group was prescribed 300 mg of allopurinol PO daily by their treating physician and followed prospectively for 8-weeks. The control group consumed a similar pill once a day for 8-weeks.

Results

ANCOVA revealed significant differences in total cholesterol (P = 0.009) and Apo B (P = 0.006) with lower levels in the allopurinol group. A trend emerged with LDL (P = 0.052) with lower levels in the allopurinol group. No significant differences were discovered in triglycerides (P = 0.403), HDL (P = 0.762) and total Cholesterol/HDL Ratio (P = 0.455).

Conclusions

After statistically controlling for compliance and inflammation significant differences between groups were observed for total cholesterol and Apo B. In both instances the allopurinol group had lower concentrations than the placebo group. Similarly, a trend was observed in LDL with the allopurinol group having lower concentrations than the placebo group.

Epidemiological association between uric acid concentration in plasma, lipoprotein(a), and the traditional lipid profile

BACKGROUND

Elevated levels of uric acid in serum (SUA) or plasma (PUA) are increasingly related to cardiovascular disease. It is unclear whether they are independent risk factors or simply markers, reflecting association with other traditional risk factors.

METHODS

We retrospectively assessed results of a lipid profile, including total cholesterol, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), triglycerides, total cholesterol to HDL-C ratio (TC/HDL-C), the atherogenic index of plasma (AIP), and lipoprotein(a) (Lp[a]), in a large cohort of unselected adult outpatients.

RESULTS

Hyperuricemic men displayed significantly increased values of triglycerides and AIP when compared with men with normal PUA levels. In hyperuricemic women, significant differences were observed for HDL-C, triglycerides, TC/HDL-C, and AIP compared with women with normal PUA levels. The percentage of patients with unfavorable values was statistically higher for triglycerides and AIP in hyperuricemic men; for HDL-C, triglycerides, TC/HDL-C, and AIP in hyperuricemic women. In multivariable linear regression analysis triglycerides, AIP, and TC/HDL-C were independently associated with PUA in women, whereas no significant association was observed in men.

CONCLUSION

PUA measurement might be advisable in patients to identify those at increased risk of cardiovascular disease (CVD) who might benefit from further triage and intervention.

Lipoproteins in patients with isolated hyperuricemia

BACKGROUND

There have been described abnormalities in the lipoprotein profile of hyperuricemic patients, it has not been clarified wether these abnormalities are due to the hyperuricemia or to the dyslipema often associated to these patients. Our aim is to study the apolipoprotein profile in hyperuricemic patients without dyslipemia compared to a control population.

PATIENTS AND METHODS

30 hyperuricemic patients and 26 healthy controls. Measurements were of blood uric acid, total cholesterol, total triglycerides, creatinine, HDL-C, and VLDL cholesterol, triglyceride, Apo B, Apo CII and Apo CIII (1 and 2). Uric acid clearance and fractionated excretion were measured in 24 h. urine samples.

RESULTS

No significant differences were found between hyperuricemic and control patients in cholesterol, triglycerides and apo B in VLDL, or LDL and HDL cholesterol. The levels of apo B, Apo AI levels and apo CIII/apo CII were similar in the hyperuricaemic and controls.

CONCLUSIONS

There are two types of hyperuricaemic patients, one group associated to hyperlipideamia and would be included in the X Syndrome. The other group not associated to other metabolic abnormalities. Is important to distinguish between these two groups to define the prognosis of a given patient because the greater cardiovascular risk linked hyperuricaemic patients could be related to the association to others cardiovascular risks factors.

Apolipoprotein E phenotypes in patients with gout: relation with hypertriglyceridaemia

OBJECTIVE

To elucidate the relationship, if any, between lipid abnormalities and apolipoprotein E (apo E) polymorphism, by investigating apo E phenotype and allele frequency.

METHODS

Fasting blood samples were taken for determination of apo E phenotype and serum lipids in 221 male patients with gout and 141 control male subjects. Apo E phenotype was determined by one dimensional flat gel isoelectric focusing.

RESULTS

Frequencies of apo E phenotypes in gout were apo E3/3 67.9%, E4/3 18.1%, E4/4 2.3%, E4/2 1.8%, E3/2 9.5%, and E2/2 0.5%; those in control male subjects were 74.5%, 15.6%, 0%, 1.4%, 7.1%, and 1.4%, respectively. Frequencies of the e2, e3, and e4 alleles in gout were 0.061, 0.817 and 0.122, compared with the corresponding control frequencies of 0.057, 0.858 and 0.085. These differences in apo E phenotype and allele frequencies between gout and control subjects were not significant. The frequency of apo e4 allele in hyperlipidaemic gout subjects was significantly greater than that in normolipidaemic gout subjects; in contrast, its frequency was not different between hyperlipidaemic and normolipidaemic control subjects. Serum triglyceride, total cholesterol, apo B and E concentrations were significantly greater in gouty patients with the apo E4/3 phenotype than in those with gout having the apo E3/3 phenotype.

CONCLUSIONS

These data suggest that gout subjects with hyperlipidaemia (hypertriglyceridaemia, hypercholesterolaemia or both) possess the apo e4 allele with higher frequency than those with normolipidaemia. They also suggest that apo e4 may induce some susceptibility to the development of hyperlipidaemia in gout in addition to that induced by obesity or excessive alcohol consumption, and may contribute to the high prevalence of atherosclerotic diseases in gout patients.

Drug-induced gout

A number of pharmacological agents can induce hyperuricaemia, and sometimes gout, usually by interfering with the renal tubular excretion of urate but also in some instances by increasing the formation of uric acid. Alcohol is well known to have this property and in recent years diuretic-induced hyperuricaemia has become a global phenomenon. Other drugs which can cause hyperuricaemia are salicylates, pyrazinamide, ethambutol, nicotinic acid, cyclosporin, 2-ethylamino-1,3,4-thiadiazole, fructose and cytotoxic agents. A special type of 'drug-induced gout' can follow the rapid lowering of serum uric acid by allopurinol or uricosuric drugs.

Relationship between hypertriglyceridemia and uric acid production in primary gout

The relationship between uric acid metabolism and lipid levels was analyzed in 148 male subjects with primary gout. The subjects were divided into three groups according to their alcohol consumption: heavy drinkers, moderate drinkers, and nondrinkers or mild drinkers. There was no correlation between urinary uric acid excretion and serum triglyceride (TG) levels in the heavy group, but a marginally significant correlation was shown in the moderate group (P less than .05), and a significant correlation was observed in the nondrinker or mild group (P less than .001). This relationship in the nondrinker or mild group was also found to be significant after adjustment for BMI and age by multiple regression analysis. Serum lipoproteins were analyzed by sequential preparative ultracentrifugation in 21 patients with primary gout who neither drank alcohol nor were obese; VLDL-TG level, but not the VLDL cholesterol level, was found to be significantly correlated with 24-hour urinary uric acid excretion. These results indicate that there is a close correlation between the degree of uric acid production, as judged by 24-hour urinary uric acid excretion, and lipoprotein TG metabolism when the influence of alcohol intake is excluded.

Hypertriglyceridemia and hyperuricemia: effects of two fibric acid derivatives (bezafibrate and fenofibrate) in a double-blind, placebo-controlled trial

The effects of bezafibrate and fenofibrate on serum lipoproteins and serum urinary uric acid were compared. In a double-blind, placebo-controlled, cross-over study, each drug was administered in random order for 6 weeks followed by a 3-week drug-free phase to ten men with primary hypertriglyceridemia. Serum triglyceride and cholesterol concentrations decreased significantly with both fenofibrate and bezafibrate, although no significant change in serum apolipoprotein B, serum low density lipoprotein (LDL) cholesterol or serum high density lipoprotein (HDL) cholesterol concentrations was apparent. Serum uric acid levels, which were elevated on placebo and bezafibrate, were significantly reduced by 20% by fenofibrate. This was associated with an increase in renal uric acid clearance of 30% during fenofibrate therapy. Because it seems likely that hypertriglyceridemia and hyperuricemia are linked by a common carbohydrate inducibility, we studied the acute hyperuricemic response to orally administered fructose. Fructose (50 g) caused the anticipated rise in serum urate reaching a peak between 60 and 90 minutes, which was quantitatively greater in the men with hypertriglyceridemia than in healthy controls. The serum uric response to fructose was unaffected by bezafibrate, but was converted to normal by fenofibrate. The hyperuricemic action of fenofibrate is of sufficient magnitude to be of therapeutic value in the management of patients whose hypertriglyceridemia is associated with gout.

A DNA polymorphism of an apoprotein gene associates with the hypertriglyceridaemia of primary gout

Genomic hybridization analysis has been used to investigate allelic frequencies of the genes coding for the four major apoproteins of high density lipoprotein (HDL); apoproteins AI, AII, CII and CIII, in a group of Caucasian subjects with primary gout. An uncommon allelic variant of the apoprotein CIII gene (the S2 allele) was significantly more common among the patients with gout (9/48, 19%) than among normouricaemic controls who were either randomly selected (1/41, 2%, P = 0.03) or normotriglyceidaemic (0/33, 0%, P = 0.013). Approximately 46% (22/48) of the subjects with gout were hypertriglyceridaemic (with a serum triglyceride greater than 2.1 mmol/l). Of the 22 patients in this subgroup, 5 (23%) had the uncommon S1S2 genotype, which was also a significantly greater proportion than among the normotriglyceridaemic controls (P = 0.015). These data suggest that the hypertriglyceridaemia associated with primary gout may have a genetic basis. In contrast, we found no differences in the frequencies of restriction fragment length polymorphisms of the genes for apoproteins AI, AII and CII.

Effect of treatment on erythrocyte phosphoribosyl pyrophosphate synthetase and glutathione reductase activity in patients with primary gout

The activities of erythrocyte phosphoribosyl pyrophosphate (PRPP) synthetase and glutathione reductase (GTR) were studied in 26 patients with primary gout who were receiving no treatment or treatment with either allopurinol or azapropazone, and compared with the activity in a group of healthy controls. The activity of PRPP synthetase was significantly higher in the gout group and was not influenced by either drug. No significant difference in the activity of GTR was observed. The failure of either drug to suppress the increased activity of PRPP synthetase associated with gout is discussed.

Hyperlipoproteinaemia in primary gout: hyperlipoproteinaemic phenotype and influence of alcohol intake and obesity in Japan

Serum lipoprotein profiles were investigated in 108 male patients with primary gout before treatment to elucidate the prevalence of each individual phenotype of coexisting hyperlipoproteinaemia and pathogenic factors responsible for it. The mean serum triglyceride (TG) and total cholesterol (TC) levels in the patients with gout were 2.10 +/- 0.14 mmol/l and 5.26 +/- 0.10 mmol/l (mean +/- SEM) respectively, which were significantly higher (p less than 0.01 and p less than 0.05 respectively) than the levels in age matched controls without gout (1.30 +/- 0.07 mmol/l and 4.77 +/- 0.08 mmol/l respectively). Serum high density lipoprotein cholesterol (HDL-C) values were slightly decreased in patients with gout compared with controls (1.24 +/- 0.08 mmol/l v 1.40 +/- 0.03 mmol/l, p less than 0.05). Hyperlipoproteinaemia was seen in 61 patients (56%), of whom patients with type IIa, IIb, and IV hyperlipoproteinaemia formed 13, 15, and 69% respectively. Thus the prevalence of type IV hyperlipoproteinaemia was high in primary gout as compared with primary hyperlipoproteinaemia with primary hyperlipoproteinaemia (69% v 43%, p less than 0.01). The independent and relative influences of clinical data of the patients upon the concentrations of serum lipids were assessed by stepwise multiple regression analysis. Two major predictors of serum TG level were alcohol intake (p less than 0.01) and serum uric acid level (p less than 0.05). The most significant predictive variable was alcohol intake, but its influence was judged to be small (r2 = 0.067). None of the other variables, including obesity index, had any significant influence. The relationships between any of these variables and serum TC or HDL-C levels were not significant. In addition, serum lipid levels were investigated in patients with neither obesity (defined as 120% or more of ideal body weight) nor a history of alcohol intake. Their serum TG and TC concentrations were also significantly higher than the respective control levels. Thus hyperlipoproteinaemia in primary gout its unlikely to be secondary to excess alcohol intake or obesity, or both. Instead, it may result from genetic factors such as a combined hyperlipidaemic trait.

The measurement of high density lipoprotein subfractions in patients with primary gout using a simple precipitation method

We have evaluated a simple dextran sulphate precipitation method for measuring high density lipoprotein cholesterol (HDL) subfractions and have used this method to measure plasma HDL2 and HDL3 in a group of 28 patients with primary gout. These patients were found to have significantly lower levels of plasma HDL and HDL2 than a group of healthy controls, matched for age and sex and of similar body mass index (BMI); no significant difference in mean levels of the HDL3 subfraction was found however. We have confirmed the high prevalence of hypertriglyceridaemia in subjects with gout compared to controls and the mean serum triglyceride levels were significantly higher (P less than 0.01) in the gout group than in controls. We have also shown that subjects with high serum triglyceride levels tend to have low plasma HDL2 concentrations, a finding which is consistent with an inverse relationship between these two parameters. These lipid abnormalities may partly explain the high prevalence of premature atherosclerosis in patients with primary gout.

Hyperuricemia and hypertriglyceridemia: metabolic basis for the association

Hypertriglyceridemia has been reported frequently in patients with hyperuricemia and gout. The current studies have evaluated this relationship. To examine whether hypertriglyceridemia leads to hyperuricemia, IV intralipid was given to three gouty patients. Triglycerides increased from 169 to 700 mg/dl for three hours but caused no change in serum urate level or urine uric acid and oxypurine excretion. We next examined whether high carbohydrate intake increases serum urate and triglyceride levels. Four obese patients were placed on a 2000 kcal/d sucrose diet for seven days. The serum urate increased from 6.3 +/- 1.7 to 7.9 +/- 2.0 mg/dL. The percent uric acid clearance to creatinine clearance decreased from 5.9 +/- 1.3 to the lowest mean value of 3.7 +/- 1.2, while serum triglycerides increased from 106 +/- 33 to 252 +/- 57 mg/dL and blood lactate from 607 +/- 227 to 1167 +/- 381 mumol/L. A 3000 kcal/d glucose diet in four other obese subjects produced no change in serum urate levels but increased lactate and triglyceride levels. During an isocaloric sucrose diet in two normal men, the serum urate level increased from 5.3 and 4.0 to peak values of 9.5 and 7.4 mg/dL. The percent uric acid to creatinine clearance decreased from 5.6 and 6.6 to 2.9 and 3.3. The uric acid turnover did not increase. In three gouty patients the mean serum urate increased from 8.5 +/- 1.5 to 10.6 +/- 1.4 mg/dL following an isocaloric sucrose diet. The urine uric acid excretion increased from 0.30 and 0.25 to 0.37 and 0.38 mg/mg creatinine in two patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Demonstration of an abnormality of C apoprotein of very low density lipoprotein in patients with gout

The very low density (VLDL) apolipoproteins of 12 male patients with gout have been studied by analytical isoelectric focusing. The relative percentage distribution of the C apolipoproteins was calculated and compared with that from 12 normolipidaemic and 12 'lipid-matched' controls. In the gout patients apolipoprotein CII (apo CII) represented 19.6% of the VLDL C proteins and the CII/CIII2 ratio was 0.57. In the normolipidaemic controls apo CII represented 28.8% and in the lipid-matched controls 33.1% of VLDL apo C, and the CII/CIII2 ratio approached one in each control group. These differences were significant. This suggests that a reduction in VLDL apo CII may predispose to the hypertriglyceridaemia that is commonly found in patients with gout.

Effects of smoking and physical activity on serum uric acid in a Jerusalem population sample

In 932 adult males and 531 adult females, we found large independent correlations of serum uric acid (SUA) with body mass and serum creatinine. In males, but not in females, SUA was lower in smokers than in non-smokers and in men who reported themselves to be physically active, compared to non-active men. After controlling for confounding variables by multiple regression analysis, we found that smoking remained a significant predictor of SUA in males (P = 0.003) but the effects of reported physical activity dropped to borderline significance (P = 0.056). In females, no significant relationship of SUA with reported physical activity was seen. These results, the first from an unselected free-living Israeli population, are generally in agreement with previously reported studies.

Serum lipids and lipoproteins in patients with primary gout

Serum lipid and lipoprotein values of 32 male patients suffering from gout were quantitated and compared with corresponding values of a random control group which did not differ significantly with regard to age, body weight index and socio-economic status. All patients were on therapy with allopurinol which lasted on average for 6 years. The most striking differences between patients and controls were the increased triglyceride and apo B values and the decreased HDL-cholesterol (HDL-C) and HDL-phospholipid (HDL-PL) values in the patient group. The values of total cholesterol, LDL-cholesterol, apo A-I and Lp (a) were not significantly different between patients and controls. The great differences in the ratios of apo B/LDL-C, apo A-I/HDL-C and apo A-I/HDL-PL values suggest that gout is connected with changes in the chemical composition of the major lipoprotein classes. In three normolipemic individuals who were treated for 3 weeks with allopurinol no changes in lipoproteins and apolipoproteins were apparent. The results are discussed in view of the atherosclerosis risk of patients suffering from gout.

Musculoskeletal disorders in patients with hyperlipidaemia

We have assessed the nature and significance of musculoskeletal disorders in 166 patients with the commonly encountered forms of hyperlipidaemia attending a lipid clinic. The incidence of musculoskeletal disorders was determined by questionnaire to the patients, inquiries to general practitioners, and a review of hospital records. To ensure the sensitivity of these methods a series of negatively responding cases were seen and examined; none had identifiable musculoskeletal disease. Eight males with type IV hyperlipidaemia had recurrent acute attacks of gout. The only other musculoskeletal disorder possibly attributable to an association with hyperlipidaemia was a transient polyarthritis in 3 patients. This was inflammatory, recurrent, but nondeforming, and involved the small joints of the hand. It did not require any specific therapy or lead to disability. We suggest that, while we have confirmed the association of type IV hyperlipidaemia and gout, there is little evidence for clinically significant arthritis being associated with other commonly presenting forms of hyperlipidaemia, although we accept that the rarely met homozygous familial hypercholesterolaemia may also be complicated by a crystal arthropathy due to the presence of crystalline cholesterol in joints.

A controlled study of diet in patients with gout

To determine whether patients with gout have a diet which is distinctive in quality or quantity a careful dietary questionnaire was posed over 7 days to 61 men with gout and 52 control subjects. The average daily intake of most nutrients, including total purine nitrogen, was similar except that the patients with gout drank significantly more alcohol. Beer was the most popular beverage, and 25 (41%) of those with gout consumed more than 60 g alcohol daily (equivalent to 2 . 5 litres of beer). The heavy drinkers had a significantly higher intake of purine nitrogen, half of which was derived from beer. Though the effect of ingested purine on the blood uric acid is difficult to estimate, it probably was sufficient to have a clinical effect, augmenting the hyperuricaemic effect of alcohol itself.

Proceedings of a symposium on crystal-related arthropathies. 22 October and 23 October, 1982, Bristol Polytechnic, Bristol

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Ethanol-induced hyperuricemia: evidence for increased urate production by activation of adenine nucleotide turnover

Consumption of alcoholic beverages is associated with hyperuricemia and gout. To determine the contributions to this process of increased production and decreased excretion of uric acid, we gave oral ethanol (1.8 g per kilogram of body weight every 24 hours) for eight days or intravenous ethanol (0.25 to 0.35 g per kilogram per hour) for two hours to six patients with gout. During the long-term oral study we observed the following: serum urate levels increased from 8.4 +/- 0.4 (mean +/- S.E.) to 10.1 +/- 0.9 mg per deciliter; whole blood lactate reached a peak of 3.1 +/- 0.7 mM from a base line of 1.3 +/- 0.3 mM; and urinary oxypurines increased to 641 +/- 397 per cent of the base-line value. Urate clearance increased to 145 +/- 25 per cent of the base-line value. Daily uric acid turnover increased from 1010 mg per deciliter to 170 +/- 17 per cent of the base-line value. During short-term intravenous ethanol administration, serum urate levels, urate clearance, and urinary uric acid excretion were not substantially altered from the base-line period. Urinary oxypurine levels increased to 341 to 415 per cent of base-line values. Urinary radioactivity, originating from the adenine nucleotide pool labeled by [8-(14)C]adenine, increased to 127 to 149 per cent of base-line values. These data indicate that ethanol increases urate synthesis by enhancing the turnover of adenine nucleotides.

Family study of lipid and purine levels in gout patients

A family study was performed to determine whether the hypertriglyceridaemia associated with gout is present in families of gout patients or due to the life style of the patient himself. The study revealed the expected hypertriglyceridaemia in gout patients; this was reflected by elevated serum levels of prebetalipoproteins and with reduction in the proportion of beta-lipoprotein. None of these abnormalities were seen in the first-degree relatives. Furthermore, the proportion of high-density lipoproteins was not significantly raised in gout patients.

Renal impairment and gout

A study of renal function of 51 patients with gout and an equal number of normouricaemic controls revealed significant differences. A relative impairment of the glomerular filtration rate and urine concentrating ability in the gouty subjects could not be wholly explained on the basis of aging or hypertension. Renal dysfunction was generally mild and was not associated with specific clinical characteristics higher levels of uric acid excretion, or hypertriglyceridaemia. Gout patients excreted urine with a significantly lower pH. This was associated with a relatively high excretion of titratable acid and a deficit of ammonium excretion, which was accentuated by ingestion of an acid load. Urate clearance was significantly reduced in gout, even when expressed as a fraction of the glomerular filtration rate.

Family study of lipid and purine levels in gout patients and analysis of mortality

A family study was performed to determine whether the hypertriglyceridaemia associated with gout is present in families of gout patients or simply due to their life-style. The study revealed hypertriglyceridaemia in gout patients, reflected by hyperprebetalipoproteinaemia and with reciprocal reduction in the proportion of beta-lipoprotein. These abnormalities were not seen in first-degree relatives. No definite increase in mortality was found from coronary or cerebrovascular disease in male gout patients after presentation to hospital or in their relatives. Families of hyperlipidaemic gout patients did reveal a slight increase in male coronary deaths although the significance of this finding was doubtful since some hypercholesterolaemia was found in these hyperlipidaemic families.

Mechanism and treatment of hypertriglyceridaemia in gout

Using the Intralipid lipid tolerance test we could not demonstrate any direct effect of serum triglyceride on uric acid or any influence of hyperuricaemia on triglyceride removal. This result supports previous studies suggesting that hyperuricaemia and hypertriglyceridaemia are linked through the association of obesity and alcohol excess rather than a direct cause and effect mechanism. It was possible to demonstrate significant reductions of serum triglyceride in patients with gout by reducing either their alcohol intake or body weight. Reduction of serum uric acid by probenecid had no effect on serum triglyceride or cholesterol. Similarly, allopurinol had no significant effect on serum triglyceride, but a significant fall of serum cholesterol was observed.

The effects of fasting in Ramadan. 1. Serum uric acid and lipid concentrations

1. The changes in serum levels of uric acid and lipids during 1 month of starvation-refeeding were measured in sixteen male volunteers. 2. Uric acid levels increased linearly with the duration of the experiment. The increase was positively correlated with the increase in serum triglycerides but not with cholesterol or phospholipids. 3. Triglycerides increased at a faster rate than uric acid implying that the increase in uric acid was secondary to that of the lipid. 4. It was concluded that the purine and lipid synthetic pathways are linked through a common small-molecular-weight effector rather than through the sharing of a common enzyme.

The effect of weight loss on plasma and urinary uric acid and lipid levels

Plasma uric acid levels in 35 obese gouty and non-gouty subjects showed a highly significant mean fall of 0.6 mg/100 ml after weight reduction on a low-calorie diet. Urinary urate also fell by a mean value of 87 mg/100 ml. Serum cholesterol and triglyceride levels have been studied in 20 of the subjects. Both have shown some overall fall with weight loss. So far the degree of change of plasma urate has shown a correlation with that of cholesterol but not that of triglyceride, but further data are needed on these inter-relationships.