Association of serum uric acid with visceral, subcutaneous and hepatic fat quantified by magnetic resonance imaging

L-shaped association between lean body mass to visceral fat mass ratio with hyperuricemia: a cross-sectional study

BACKGROUND

Insufficient attention has been given to examining the correlation between body composition and hyperuricemia, leading to inconsistent findings. The primary objective of this research is to explore the association between lean body mass index (LMI), visceral fat mass index (VFMI), and hyperuricemia. A specific emphasis will be placed on assessing the link between the ratio of lean body mass to visceral fat mass (LMI/VFMI) and hyperuricemia.

METHODS

The present study employed a cross-sectional design and involved a total of 9,646 individuals who participated in the National Health and Nutrition Examination Survey (NHANES). To explore the associations among the variables, logistic and linear regressions were employed. Additionally, subgroup analyses and sensitivity analyses were conducted based on various characteristics.

RESULTS

The results showed that LMI was positively associated with hyperuricemia (for Per-SD: OR = 1.88, 95%CI: 1.75, 2.01; for quartiles [Q4:Q1]: OR = 5.37, 95%CI: 4.31, 6.69). Meanwhile, VFMI showed a positive association with hyperuricemia (for Per-SD: OR = 2.02, 95%CI: 1.88, 2.16; for quartiles [Q4:Q1]: OR =8.37, 95%CI: 6.70, 10.47). When considering the effects of In LMI/VFMI, an L-shaped negative association with hyperuricemia was observed (for Per-SD: OR = 0.45, 95%CI: 0.42, 0.49; for quartiles [Q4:Q1]: OR = 0.16, 95%CI: 0.13, 0.20). Subgroup and sensitivity analyses demonstrated the robustness of this association across different subgroups. Additionally, the segmented regression analysis indicated a saturation effect of 5.64 for the In LMI/VFMI with hyperuricemia (OR = 0.20, 95%CI: 0.17, 0.24). For every 2.72-fold increase of In LMI/VFMI, the risk of hyperuricemia was reduced by 80%.

CONCLUSION

The LMI/VFMI ratio is non-linearly associated with serum uric acid. Whether this association is causal needs to be confirmed in further longitudinal studies or Mendelian randomization.

Nonlinear relationship between body mass index and serum uric acid: An observational and Mendelian randomization study among Chinese adults

BACKGROUND AND AIMS

Conflicting evidence exists on the relationship between body mass index (BMI) and serum uric acid (SUA), and importantly, the causal role of BMI in SUA remains unclear. We aimed to evaluate the BMI-SUA relationship and its causality among Chinese adults using observational and Mendelian randomization (MR) analyses.

METHODS AND RESULTS

Study included 6641 adults from East China. A genetic risk score based on 14 BMI-associated East Asian variants was formulated. One-sample MR and non-linear MR analyses assessed the causal link between BMI_GRS and SUA levels. Mean BMI levels were 24.8 (SD 3.4) and 24.3 (SD 3.6) kg/m2 in men and women, respectively. Spline models revealed gender-specific BMI-SUA associations: a reverse J-shape for men and a J-shape for women (P-values for nonlinearity <0.05). In men, BMI showed a positive correlation with SUA levels when BMI was below 29.6 kg/m2 (beta coefficient 19.1 [95 % CI 15.1, 23.0] μmol/L per 1-SD increase in BMI), while in women, BMI exhibited a negative correlation with SUA levels when the BMI was less than 21.7 kg/m2 (beta coefficient -12.9 [95 % CI -21.6, -4.1] μmol/L) and a positive correlation when BMI exceeded 21.7 kg/m2 (beta coefficient 13.3 [95 % CI 10.9, 15.8] μmol/L). Furthermore, MR analysis suggested non-linear BMI-SUA link in women but not men.

CONCLUSION

Our study indicates a non-linear correlation between BMI and SUA in both genders. It is noteworthy that in women, this correlation may have a causal nature. Nevertheless, further longitudinal investigations are required to authenticate our findings.

Association between anthropometric indices and hyperuricemia: a nationwide study in China

This article explored the relationship between anthropometric indices and hyperuricemia in Chinese adults. The ability of each anthropometric index to predict hyperuricemia was also compared in this article. This is a cross-sectional study containing 69,842 samples from 31 provinces and cities in China. Anthropometric indices included body mass index (BMI), waist circumference (WC), a body shape index (ABSI), body roundness index (BRI), waist-to-height ratio (WHtR), lipid accumulation product (LAP), visceral adiposity index (VAI), triglyceride-glucose index (TyG), waist circumference-triglyceride index (WTI), and weight-adjusted waist index (WWI). The survey data obtained were disaggregated and analyzed according to sex and age. BMI, WC, BRI, WHtR, LAP, VAI, TyG, WTI, and WWI were all significantly associated with hyperuricemia (P < 0.001). In the total population, WTI (AUC 0.7015, P < 0.001) had the highest predictive power, and WWI (AUC 0.5417, P < 0.001) had the lowest. In addition, after dividing the male and female populations, LAP (AUC 0.6571, P < 0.001 for men; AUC 0.7326, P < 0.001 for women) had the highest predictive power among both men and women. The ABSI (AUC 0.5189, P < 0.001 for men; AUC 0.5788, P < 0.001 for women) had the lowest predictive power among both men and women. BMI, WC, BRI, WHtR, LAP, VAI, TyG, and WTI were positively correlated with the risk of hyperuricemia and serum uric acid concentrations in both sexes. Among the general population, WTI had the highest predictive power. After dividing the population by sex, LAP had the highest predictive power in both men and women. Key Points • Anthropometric indices are highly correlated with hyperuricemia. Waist circumference-triglyceride index (WTI) is first found to be associated with hyperuricemia, and it has high predictive power. • The predictive power of anthropometric indices for hyperuricemia is more useful in women. • The restricted cubic splines visually shows the ratio of anthropometric indices to hyperuricemia ratio and the patient's serum uric acid concentration.

Sex-specific differences in the associations between adiposity indices and incident hyperuricemia among middle-aged and older adults: a nationwide longitudinal study

Objective

Although obesity is a known risk for hyperuricemia (HUA), the associations between adiposity indices and incident HUA and whether sex-specific differences exist is still unknown. We aimed to investigate the associations between adiposity indices and incident HUA in a longitudinal study.

Methods

Data from the China Health and Retirement Longitudinal Study (CHARLS) in 2011-2012 and 2015-2016 were used to conduct a cohort study. Participants aged ≥45 years without HUA at baseline were included in this study. Adiposity indices, including body mass index (BMI), waist circumference (WC), waist-to-height ratio body roundness index (BRI), conicity index (CI), lipid accumulation product (LAP) index, waist-to-height ratio (WHtR), visceral adiposity index (VAI), and Chinese visceral adiposity index (CVAI), were calculated. Logistic analysis was used to analyze the association between adiposity indices and incident HUA risk stratified by gender. Receiver operating characteristic curve analysis was performed to evaluate the power of predictions for incident HUA.

Results

Of 5,873 participants aged 59.0 ± 8.7 years enrolled in this study, 578 (9.8%) participants developed HUA during the 4-year follow-up period. After adjusting for confounding variables, LAP, VAI, and CVAI showed significant association with incident HUA. BMI, WC, WHtR, BRI, and CI were significantly associated with incident HUA in women but not in men. LAP had the highest area under the curve (AUC) (0.612) followed by CVAI (0.596) in men, while CVAI had the highest AUC (0.707) followed by LAP (0.691) in women. All indices showed better predictive ability in women than in men.

Conclusion

Our findings indicated that adiposity indices were effective predictors of incident HUA and showed better predictive power in women than men. In clinical practice, adiposity indices could be used to assess and prevent incident HUA among Chinese middle-aged and older adults.

Uric acid and diabetes mellitus: an update

The relationship between diabetes mellitus (DM) and high serum uric acid is complex and controversial. Many epidemiological studies have reported a positive association, whereas others have reported an inverse association or none. In the pathogenesis of DM it is the intracellular urate that is more important than the extracellular and dissociation between the two is possible. Evidence suggests that high serum uric acid induces insulin resistance and beta cell failure in animal models. Reduction of intracellular uric acid can be achieved by dietary measures such as reducing fructose and salt intake, and uric acid-lowering drugs. We suggest that in the Western diet, these elements play a crucial role in pathogenesis of DM. To determine the precise and exact interrelationship between intracellular and extracellular uric acid, well-designed studies are required. Besides this, clinical trials are needed to determine whether intracellular and extracellular urate reduction will provide benefit in prevention and treatment of DM and complications associated with it.

Novel pathological implications of serum uric acid with cardiovascular disease risk in obesity

AIMS

This cohort study intended to elucidate the association between serum uric acid (SUA) levels and cardiovascular disease events in Japanese patients with obesity.

METHODS

Altogether, 450 obese Japanese outpatients were enrolled in a multicenter prospective cohort Japan, the Japan Obesity and Metabolic Syndrome Study. Primary analysis regarding the measurements of cardiovascular risk factors, including SUA levels, and the occurrence of macrovascular complications was based on following the participants over a 5-year period.

RESULTS

Of the eligible patients, 335 (74.4%) were followed into the fifth year. During the study period, 15 coronary heart disease, 7 stroke, and 6 arteriosclerosis obliterans events occurred in 39 patients. The CVD incidence rate was 15.8 per 1000 person-years. In the analysis of adjusted models for traditional risk factors, hyperuricemia was a significant factor for the incidence of CVD events, especially in female obese patients. Additionally, we estimated the association between SUA levels and CVD events using cubic spline models, which showed a U-shaped association in both male and female patients.

CONCLUSIONS

SUA is an effective predictor of CVD events in female obese patients and a risk factor for CVD incident in obese patients.

Higher serum uric acid is associated with body fat, retinol-binding protein 4, and antioxidative status in Brazilian children

OBJECTIVE

The aim of this study was to evaluate the association of serum uric acid (SUA) with adiposity, adipokines, and anti- and oxidative markers in Brazilian children.

METHODS

This was a cross-sectional investigation with 378 children ages 8 to 9 y in Viçosa, Minas Gerais, Brazil. Information on sociodemographic and lifestyle characteristics was obtained via questionnaires, and body fat was determined by dual energy x-ray absorptiometry. We compared the distributions of adiposity (total and central), adipokines (adiponectin, chemerin, leptin, and retinol-binding protein 4 [RBP4]), anti- and oxidative markers (plasma ferric reducing antioxidant power [FRAP], superoxide dismutase [SOD], and malondialdehyde [MDA]) by SUA categories using linear regression.

RESULTS

SUA was positively associated with total and central fat. Every standard deviation (SD) of SUA was related, respectively, to a 3.4 (95% confidence interval [CI], 2.4-4.4), 4 (95% CI, 2.8-5.1), 4.2 (95% CI, 2.9-5.5), and 3.5 (95% CI, 2.4-4.6) units higher of total, truncal, android, and gynoid fat. We found a positive association of SUA with RBP4 and FRAP, and a negative association with MDA. Every SD of SUA was related, respectively, to 0.1 (95% CI, 0.01-0.1) and 7.8 (95% CI, 5.5-10.1) units higher of RBP4 and FRAP; and to -0.3 (95% CI, -0.5 to -0.1) units lower of MDA.

CONCLUSIONS

SUA was positively associated with adiposity, RBP4, and antioxidative status in Brazilian children.

Total Antioxidant Capacity in Obese and Non-Obese Subjects and Its Association with Anthropo-Metabolic Markers: Systematic Review and Meta-Analysis

The total antioxidant capacity (TAC) has been related to the development of and complications associated with chronic diseases, but its importance during obesity is not entirely clear. We conducted a systematic review and meta-analysis to clarify whether there are differences or similarities in the TAC between subjects with obesity (SO) and subjects with normal weight (NW). Following the recommendations of PRISMA and Cochrane, we performed a systematic search in the PubMed, Scopus, Web of Science, Cochrane, and PROSPERO databases, identifying 1607 studies. Among these, 22 studies were included in the final analysis, comprising 3937 subjects (1665 SO and 2272 NW) in whom serum TAC was measured, and from these 19,201 subjects, the correlation of serum TAC with anthropo-metabolic parameters was also estimated. The Newcastle-Ottawa method was used for the evaluation of the risk of bias. Using a random-effect model (REM), TAC was reduced in SO independently of age (SMD, -0.86; 95% CI -1.38 to -0.34; p = 0.0012), whereas malondialdehyde (SMD, 1.50; 95% CI 0.60 to 2.41), oxidative stress index (SMD, 1.0; 95% CI 0.16 to 1.84), and total oxidant status (SMD, 0.80; 0.22 to 1.37) were increased. There were seven significant pooled correlations of TAC with anthropometric and metabolic parameters: weight (r = -0.17), hip circumference (r= -0.11), visceral adipose index (r = 0.29), triglycerides (r = 0.25), aspartate aminotransferase (r = 0.41), alanine aminotransferase (r = 0.38), and uric acid (r = 0.53). Our results confirm a decrease in TAC and an increase in markers of oxidative stress in SO and underpin the importance of these serum biomarkers in obesity.

Uric acid level in climacteric women and its association with clinical and metabolic parameters

Climacteric women often experience unfavorable metabolic changes. Consequently, identifying markers that may contribute to such undesirable changes is imperative. This study aimed to evaluate serum uric acid (UA) concentration and its association with metabolic and clinical parameters in climacteric women. We selected 672 women between 40 and 65 years and performed interviews, biochemical analyses, blood pressure, and anthropometric measurements. UA levels were determined using the enzymatic-colorimetric method. We compared variables according to the quartiles of UA using the Kruskal-Wallis test. The mean UA level was 4.9 ± 1.5 mg/dl, ranging from 2.0 to 11.6 mg/dl. We found that UA levels greater than 4.8 mg/dl were associated with adverse metabolic parameters in climacteric women. For all anthropometric and biochemical variables, we observed significantly better results in women who had lower UA levels (p < 0.05). Similarly, we observed a significant increase in blood pressure, frequency of metabolic syndrome, and cardiovascular risk as UA levels increased (p < 0.05). Our findings showed that climacteric women with high levels of UA were more likely to have adverse metabolic and clinical parameters than those with lower UA levels. Further studies may determine the causal relationship between UA and metabolic changes in climacteric women.

Association between serum uric acid and measures of adiposity in Chinese adults: a cross-sectional study

OBJECTIVE

The purposes of the study were to investigate the detailed association of serum uric acid (SUA) with visceral fat area (VFA) and body fat percentage (BFP) as calculated by bioelectrical impedance analysis (BIA) and build non-invasive diagnosis models of hyperuricaemia by combining obesity-related indicators, age and sex.

METHOD

A total of 19 343 adults were included. Multivariable regression analysis models were employed to analyse the association of SUA with VFA and BFP. Receiver operating characteristic curves were generated to diagnose hyperuricaemia in adults.

RESULTS

After fully adjusting for covariates, SUA was positively associated with VFA, BFP and body mass index (BMI) with βs of 0.447, 2.522 and 4.630 (95% CI= (0.412 to 0.482), (2.321 to 2.723) and (4.266 to 4.994)). After stratification by gender, this association persists (p<0.001). Fitted smoothing curves identified non-linear relationships between SUA and both VFA and BMI after full adjustment in males (inflection points: 93.9 cm² and 30.9 kg/m²). A non-linear relationship also exists between SUA and BFP in females (inflection point: 34.5%). A combined model incorporating BFP, BMI, age and sex exhibited the best ability to diagnose hyperuricaemia (AUC (area under the curve) =0.805, specificity=0.602, sensitivity=0.878). For normal-weight and lean populations, individuals with hyperuricaemia tended to have higher levels of VFA and BFP in females and males, respectively (p<0.001). The combination of VFA, BFP, BMI, age and sex exhibited the best ability to diagnose hyperuricaemia in normal-weight and lean populations (AUC=0.803, specificity=0.671, sensitivity=0.836).

CONCLUSION

VFA and BFP are independent factors associated with SUA. In males, SUA shows a non-linear relationship with VFA and BMI. In females, SUA and BFP exhibit a non-linear relationship. In normal-weight and lean individuals, the accumulation of VFA and BFP may be involved in hyperuricaemia. VFA and BFP were helpful in diagnosing hyperuricaemia in adults, especially for normal-weight and lean populations.

Influence of the TAS2R38 Gene Single Nucleotide Polymorphisms in Metabolism and Anthropometry in Thyroid Dysfunction

The gene TAS2R38 single nucleotide polymorphisms (SNPs-P49A, A262V and V296I) can condition bitter tasting by PAV (proline-alanine-valine) and non-bitter-tasting by AVI (alanine-valine-isoleucine) homozygosity. We evaluated this polymorphisms association with thyroid function, metabolism and anthropometry parameters determined by: Endpoint analysis (SNPs); DXA (fat mass-%, total fat mass-kg, lean mass-kg); Standard methods (lipid metabolism parameters, HbA1c-%, glycemia-mg/dL, insulinemia-µIU/mL, HOMA-IR, uricemia-mg/dL, calcemia-mg/dL and BMI-kg/m²); ELISA (leptinemia-ng/mL); Spectrophotometry (Angiotensin Converting Enzyme activity-UI/L). Statistics: SPSS program; OR [IC95%]; p < 0.05. Sample: 114 hypothyroid, 49 hyperthyroid, and 179 controls. An association between A262V-valine-valine and hypothyroidism/hyperthyroidism was verified (OR = 2.841; IC95% [1.726-4.676]), p < 0.001/OR = 8.915; IC95% [4.286-18.543]), p < 0.001). Protector effect from thyroid dysfunction: A262V-alanine-valine (OR = 0.467; IC95% [0.289-0.757], p = 0.002/OR = 0.132; IC95% [0.056-0.309], p < 0.001) and PAV (OR = 0.456; IC95% [0.282-0.737], p = 0.001/OR = 0.101; IC95% [0.041-0.250], p < 0.001). Higher parameter values associated with genotypes were: fat-mass-% (V296I-valine-isoleucine), lean-mass (P49A-proline-proline; PVI), leptin (AVI), HbA1c (A262V-alanine-valine) and lower values in lean-Mass (AVI; PVV), leptin (A262V-alanine-alanine), HbA1c (PVV), uricemia (V296I-valine-isoleucine), glycemia (A262V-alanine-alanine; AAV) and plasma triglycerides (PVV). In conclusion, TAS2R38 influences thyroid function, body composition and metabolism. Bitter taste perception (PAV) and the genotype A262V-alanine-valine can protect from thyroid dysfunction. AVV, PVV and genotype A262V-valine-valine may confer higher predisposition for thyroid dysfunction, particularly PVV for hyperthyroidism.

The Longitudinal Changes in Subcutaneous Abdominal Tissue and Visceral Adipose Tissue Volumetries Are Associated with Iron Status

Excess iron is known to trigger adipose tissue dysfunction and insulin resistance. Circulating markers of iron status have been associated with obesity and adipose tissue in cross-sectional studies. We aimed to evaluate whether iron status is linked to changes in abdominal adipose tissue longitudinally. Subcutaneous abdominal tissue (SAT) and visceral adipose tissue (VAT) and its quotient (pSAT) were assessed using magnetic resonance imaging (MRI), at baseline and after one year of follow-up, in 131 (79 in follow-up) apparently healthy subjects, with and without obesity. Insulin sensitivity (euglycemic- hyperinsulinemic clamp) and markers of iron status were also evaluated. Baseline serum hepcidin (p = 0.005 and p = 0.002) and ferritin (p = 0.02 and p = 0.01)) were associated with an increase in VAT and SAT over one year in all subjects, while serum transferrin (p = 0.01 and p = 0.03) and total iron-binding capacity (p = 0.02 and p = 0.04) were negatively associated. These associations were mainly observed in women and in subjects without obesity, and were independent of insulin sensitivity. After controlling for age and sex, serum hepcidin was significantly associated with changes in subcutaneous abdominal tissue index (iSAT) (β = 0.406, p = 0.007) and visceral adipose tissue index (iVAT) (β = 0.306, p = 0.04), while changes in insulin sensitivity (β = 0.287, p = 0.03) and fasting triglycerides (β = -0.285, p = 0.03) were associated with changes in pSAT. These data indicated that serum hepcidin are associated with longitudinal changes in SAT and VAT, independently of insulin sensitivity. This would be the first prospective study evaluating the redistribution of fat according to iron status and chronic inflammation.

Laboratory Findings in Children with Excess Body Weight in Romania

Background and Objectives: Childhood obesity has been increasing at a worrisome pace and emerging as a non-infectious pandemic in the pediatric population in recent years. Raising awareness on this problem is of utmost importance, in order to take action to control body weight from an early age. Materials and Methods: We performed a retrospective study among overweight or obese children evaluated on an outpatient basis in the Department of Pediatric Endocrinology of a tertiary care hospital in Bucharest Romania in 2021 in order to identify laboratory changes occurring according to age and sex. Results: A total of 268 children were included in the analysis, with a median age of 10.9 years (IQR: 8.3, 13.3 years); 61.8% were obese and 38.2% overweight. We identified a subclinical pro-inflammatory status characterized by increased neutrophil count (12.7%) and increased C-reactive protein (16.4%). Biochemically, we identified the highest increases for uric acid (35.4%). More than half of the children included in the study had dyslipidemia-specific changes: high low-density lipoprotein cholesterol (LDL) (50.0%), low high-density lipoprotein cholesterol (HDL) (58.9%) and increased triglyceride levels (12.7%), especially children with a body mass-index (BMI) percentile above 95%. Increased thyroid stimulating hormone (TSH) was identified in 20.3% and low thyroxine (T4) level in 13.4%, especially in females. Conclusions: Early measures to control excess body weight are needed since preventing obesity is easier than treating it. However, this is often difficult to do in our country because parents frequently do not recognize the problem until it is advanced. Furthermore, doctors are not always adequately prepared and sometimes they do not have the support of the health systems to provide children in need with the adequate care. Educational strategies and awareness of issue should be revisited in current post-pandemic context that facilitates increase of obesity prevalence in children. Increase of efficient communication could be achieved by pointing to these objective findings.

Relationship between bone mineral density and hyperuricemia in obesity: A cross-sectional study

BACKGROUND

Obesity is an increasingly severe global public health issue. This study aims to estimate the cross-sectional association between bone mineral density (BMD) and hyperuricemia (HU) in obesity.

METHOD

A total of 275 obese subjects (126 men and 149 women) participated in this cross-sectional study. Obesity was diagnosed as body mass index (BMI) ≥28 kg/m², whereas HU was defined as the blood uric acid level of 416 μmol/L in men and 360 μmol/L in women. The BMD of the lumbar spine and right hip was measured by dual-energy X-ray absorptiometry (DXA). The multivariable logistic regressions were employed to examine the relationship between BMD and HU in obesity, with the adjustment of gender, age, fasting blood glucose, fasting insulin, homeostasis model assessment of insulin resistance (HOMA-IR), cholesterol, triglycerides, low-density lipoprotein, high-density lipoprotein, creatinine, blood urea nitrogen, high-sensitivity C-reactive protein (hs-CRP), cigarette smoking, and alcohol drinking status.

RESULT

The overall prevalence of HU was 66.9% in this obese population. The mean age and BMI of this population were 27.9 ± 9.9 years and 35.2 ± 5.2 kg/m², respectively. The multivariable-adjusted OR (the highest vs. lowest BMD quartile) demonstrated a negative relationship between BMD and HU in total (OR = 0.415, 95%CI: 0.182-0.946; p = 0.036), L1 (OR = 0.305, 95%CI: 0.127-0.730; p = 0.008), L2 (OR = 0.405, 95%CI: 0.177-0.925; p = 0.032), and L3 (OR = 0.368, 95%CI: 0.159-0.851; p = 0.020) lumbar vertebrae. In the subgroup analysis for the male population, the BMD was also negatively associated with HU in total (OR = 0.077, 95%CI: 0.014-0.427; p = 0.003), L1 (OR = 0.019, 95%CI: 0.002-0.206; p = 0.001), L2 (OR = 0.161, 95%CI: 0.034-0.767; p = 0.022), L3 (OR = 0.186, 95%CI: 0.041-0.858; p = 0.031), and L4 (OR = 0.231, 95%CI: 0.056-0.948; p = 0.042) lumbar vertebrae. However, such findings did not exist in women. In addition, there was no significant relationship between hip BMD and HU in obesity.

CONCLUSION

Our results showed that the lumbar BMD was negatively associated with HU in obesity. However, such findings only existed in men, rather than women. In addition, no significant relationship between hip BMD and HU existed in obesity. Due to the limited sample size and nature of the cross-sectional design, further large prospective studies are still needed to clarify the issues.

Associations Between Low Serum Urate, Body Composition, and Mortality

OBJECTIVE

Controversy remains as to whether low serum urate or uric acid (UA) levels contribute to adverse outcomes. We evaluated the relation between low serum UA levels and sarcopenia and assessed whether sarcopenia confounds associations between these low levels and mortality.

METHODS

We utilized data from the National Health and Nutrition Examination Survey (1999-2006). Participants with available whole-body dual x-ray absorptiometry body composition measurements and serum UA concentrations were included. Body composition assessments included body mass index (BMI), waist circumference, maximum lifetime BMI, and age-, sex-, and race-specific appendicular lean mass index (ALMI) and fat mass index (FMI) Z scores. We also calculated Z scores for ALMI relative to FMI (ALMIFMI ). We evaluated associations between serum UA levels and body composition using logistic regression and assessed associations between serum UA levels and mortality before and after adjusting for differences in body composition using Cox proportional hazards regression.

RESULTS

Among the 13,979 participants, low serum UA concentrations (<2.5 mg/dl in women, <3.5 mg/dl in men) were associated with low lean mass (ALMI and ALMIFMI Z scores), underweight BMI (<18.5 kg/m2 ), and higher rates of weight loss. The proportion of patients with low ALMI Z scores was 29% in the low serum UA group and 16% in the normal serum UA group (P = 0.001). Low serum UA levels were associated with increased mortality before we adjusted for body composition (hazard ratio 1.61 [95% confidence interval 1.14-2.28]; P = 0.008) but was attenuated and not significant after adjustment for body composition and weight loss (hazard ratio 1.30 [95% confidence interval 0.92-1.85], P = 0.13).

CONCLUSION

Sarcopenia and weight loss are more common among patients with low serum UA concentrations. Differences in body composition may help to explain associations between low levels of serum UA and higher mortality.

Increased risk of incident gout in young men with metabolic syndrome: A nationwide population-based cohort study of 3.5 million men

Background

To date, few studies have focused on risk factors for gout in young people, and large-scale studies on the relationship between metabolic syndrome (MetS) and gout are lacking. We aimed to investigate the association between gout and MetS in a large nationwide population-based cohort of young men who participated in national health examination.

Materials and methods

Cohort included men aged 20–39 years who participated in a health check-up in 2009–2012. A total of 3,569,104 subjects was included in the study, excluding those who had a previous diagnosis of gout or had renal impairment. The outcome was the occurrence of gout, which was defined using the diagnosis code of gout in the claims database. Cox proportional hazard model was used to evaluate the association between MetS and incident gout.

Results

Mean follow-up duration was 7.35 ± 1.24 years and the incidence rate of gout was 3.36 per 1,000 person-years. The risk of gout in subjects with MetS was 2.4-fold higher than subjects without MetS. Among the components of MetS, hypertriglyceridemia and abdominal obesity showed the greatest association with gout. As the number of MetS components increased, the risk of gout increased. The association between gout and MetS was more pronounced in relatively young subjects and in low- or normal-weight subjects.

Conclusion

Metabolic syndrome is an important risk factor for the gout in young men. In particular, the association between MetS and gout was greater in young and non-obese men. Management of MetS in young men will be important for future gout prevention.

Relationships among green space, ambient fine particulate matter, and cancer incidence in Taiwan: A 16-year retrospective cohort study

INTRODUCTION

Green space and air pollution have been recognized as vital health determinants. There is a paucity of studies examining the interplay between green space, fine particulate matter (PM_2.5), and the incidence of specific cancers.

OBJECTIVE

We aimed to explore the contributions of green space and ambient PM_2.5 to the risk of specific cancers in terms of the most common cancers based on incidence or mortality rate in Taiwan and to ascertain the interaction between green space and PM_2.5 and their role in cancer risk.

MATERIALS AND METHODS

This retrospective longitudinal cohort study included 407,415 participants. Data were obtained from the 2000-2015 Mei Jau Health Examination Database linked to the Taiwan Cancer Registry and Causes of Death datasets. All participants were aged ≥20 years and had no history of cancer. The environmental exposure were the normalized difference vegetation index (NDVI) and the 2-year average PM_2.5 at baseline. Multivariate adjusted hazard ratios (HRs) were calculated using Cox proportional hazards models. We adjusted for covariates including demographics, anthropometrics, comorbidities, health behaviors, biochemical data, and environmental factors.

RESULTS

During a median follow-up of 10.37 years, 11,576 cancer cases were reported. PM_2.5 exposure increased the risk of all cancers (HR: 1.11, [95% CI: 1.06-1.15]), stomach cancer (HR: 1.27, [1.02-1.58]), endocrine gland cancer (HR: 2.13, [1.39-3.26]), breast cancer (HR: 1.12, [1.03-1.22]), and lung cancer (HR: 1.12, [1.01-1.24]). An increase in NDVI reduced the risk of prostate cancer (HR: 0.93, [0.88-0.99]) and lung cancer (HR: 0.95, [0.91-0.99]). NDVI influenced the incidence of prostate and all cancers by reducing PM_2.5 concentrations.

CONCLUSION

Long-term PM_2.5 exposure is associated with an increased risk of some types of cancers. In contrast, an increase in environmental green space exposure is associated with lowering of the risk of prostate and lung cancer.

Synergistic Interaction between Hyperuricemia and Abdominal Obesity as a Risk Factor for Metabolic Syndrome Components in Korean Population

BACKGROUND

The present study investigated the role of synergistic interaction between hyperuricemia and abdominal obesity as a risk factor for the components of metabolic syndrome.

METHODS

We performed a cross-sectional study using the data of 16,094 individuals from the seventh Korean National Health and Nutrition Examination Survey (2016 to 2018). The adjusted odds ratios of metabolic syndrome and its components were analyzed by multivariate logistic regression analysis. The presence of synergistic interaction between hyperuricemia and abdominal obesity was evaluated by calculating the additive scales-the relative excess risk due to interaction, attributable proportion due to interaction, and synergy index (SI).

RESULTS

There was a synergistic interaction between hyperuricemia and abdominal obesity in hypertriglyceridemia (men: SI, 1.39; 95% confidence interval [CI], 1.01 to 1.98; women: SI, 1.61; 95% CI, 1.02 to 2.69), and low high-density lipoprotein cholesterol (HDL-C) (men: SI, 2.03; 95% CI, 1.41 to 2.91; women: SI, 1.70; 95% CI, 1.05 to 2.95). There was no significant synergistic interaction between hyperuricemia and abdominal obesity for the risk of high blood pressure (men: SI, 1.22; 95% CI, 0.85 to 1.77; women: SI, 1.53; 95% CI, 0.79 to 2.97), and hyperglycemia (men: SI, 1.03; 95% CI, 0.72 to 1.47; women: SI, 1.39; 95% CI, 0.75 to 2.57).

CONCLUSION

Hyperuricemia and abdominal obesity synergistically increased the risk of hypertriglyceridemia and low HDL-C in both sexes.

Prevalence of hyperuricemia in patients with severe obesity and the relationship between serum uric acid and severe obesity: A decade retrospective cross-section study in Chinese adults

Objective

Undoubtedly, the relationship between serum uric acid (SUA) and obesity is less data for Chinese patients with obesity. This study aimed to examine the prevalence of hyperuricemia (HUA) and the association between SUA and patients with obesity.

Methods

All participants were categorized as overweight, obesity I, obesity II, and obesity III. In addition, based on SUA concentration, the participants were stratified into four quartiles. The authors used descriptive analysis, independent t-test, ANOVA, correlation analysis, and multiple linear regression models to verify the SUA level and obesity among Chinese adults.

Results

Overall, the estimated prevalence of HUA was 69.8%. In the BMI categories, the prevalence of HUA was 5.1% in overweight, 15.2% in obesity I, 16.9% in obesity II, and 32.5% in obesity III. Correlation analysis shows that SUA is strongly correlated with BMI, waist circumference (WC), and hip circumference (HC). Multiple linear regression analysis shows that high density-lipoprotein cholesterol (HDL-C) is a protective predictor of serum uric acid levels in patients with obesity. Compared with the overweight, obesity I, obesity II, and obesity III were more likely to have higher levels in the SUA levels.

Conclusion

We mainly showed that the serum uric acid levels in Chinese patients with severe obesity declined slightly as age increased.

The perirenal fat thickness was independently associated with serum uric acid level in patients with type 2 diabetes mellitus

BACKGROUND

Obesity is an important risk factor for hyperuricemia. We aimed to explore the relationship between perirenal fat thickness (PrFT) and paranephric fat thickness (PnFT) and serum uric acid (SUA) in patients with type 2 diabetes mellitus (T2DM).

METHODS

This was a cross-sectional study involving 257 patients with T2DM recruited from Beijing Luhe Hospital from September 2019 to May 2020. The basic and clinical information such as age, gender, duration of diabetes was collected through the medical records. All patients underwent a physical examination including height, weight, waist circumference, hip circumference, systolic blood pressures and diastolic blood pressure. The venous blood and urine samples were collected to measure SUA, fasting blood glucose, total cholesterol, triglyceride, low-density lipoprotein-cholesterol, high-density lipoprotein-cholesterol, serum creatinine, blood urea nitrogen and glycosylated hemoglobin. PrFT and PnFT were measured via ultrasonography. Pearson correlation test and linear regression analysis were used to analyze the association between PrFT and PnFT and SUA.

RESULTS

We found that PrFT and PnFT increased according to the tertiles of SUA level (P = 0.001 and P = 0.009, respectively). In addition, the PrFT and PnFT were positively associated with SUA level (r = 0.25, P < 0.001, r = 0.23, P < 0.001, respectively). Moreover, this association was stronger in males, non-obesity patients and patients with normal renal function. In the multivariate analysis, the PrFT was independently associated with SUA level after adjusting confounding factors.

CONCLUSIONS

The PrFT was independently associated with SUA level in patients with T2DM.

The Association Between Total Percent Fat and Serum Uric Acid in Adults

Background

Serum uric acid (SUA) has been proven to be closely associated with metabolic abnormalities, including obesity. This study aimed to investigate the detailed relationship between total percent fat (TPF) and SUA among adults.

Methods

Briefly, 23,715 adults aged 18–59 years in the National Health and Nutrition Examination Survey (NHANES) 1999–2018 were included in this study. Multivariable linear regression models were used to examine the association between TPF and SUA. Subgroup analyses stratified by sex and obesity status were also performed by multivariable linear regression. Then, fitted smoothing curves and generalized additive models were also applied to address the non-linear relationship between TPF and SUA. Finally, a recursive algorithm was used to calculate the inflection point in the non-linear relationship and a two-segment piecewise linear regression model was used to analyze the relationship between TPF and SUA on both sides of the inflection point.

Results

There were 15,808 (66.7%) obese individuals in all 23,715 participants. In the fully adjusted model, there was a positive association between TPF and SUA (β = 0.99, 95% CI: 0.73–1.26). Besides, this positive association remained statistically significant in subgroup analyses stratified by sex and obesity status. Interestingly, in males, the association of TPF and SUA was an inverted U-shaped curve (inflection point: 34.3%).

Conclusion

Our study revealed a significant positive relationship between TPF and SUA among adults and this association remained statistically significant when stratified by sex and obesity status, but the shape of the smoothing curve in males differed from that in females.

Perirenal Fat Volume Is Positively Associated With Serum Uric Acid Levels in Chinese Adults

BACKGROUND

Visceral fat has been considered an important risk factor of elevated serum uric acid (SUA). Perirenal fat is a unique visceral fat around the kidneys that has special morphological and physiological features while its relationship with SUA remains incompletely elucidated. This study aimed to assess the association between perirenal fat volume (PrFV) and SUA.

METHODS

A cross-sectional study was conducted in 102 subjects aged ≥ 18 years old recruited from Nanjing,China. The clinical characteristics including age, sex, drinking behavior, history of hypertension, body mass index, waist circumference, total cholesterol, fast plasma glucose, urea, serum creatinine, C-reactive protein, and SUA were recorded. PrFV was measured by ultrasonography. Multivariate linear models and the restricted cubic spline were used to investigate the association between PrFV and SUA.

RESULTS

The median age of this study population was 52.5 (42.0-60.0) years and 56.9% were female. The median value of SUA was 5.73 mg/dL (4.58-6.80 mg/dL). The subjects were divided by PrFV tertiles and we found that the subjects in the highest PrFV tertile had a higher level of SUA compared to those in the lowest tertile (β=1.86, 95%CI 1.23-2.48, P for trend <0.001).The positive association also remained after adjustment for potential covariates (tertile3 versus tertile1: β=0.99, 95%CI 0.35-1.63, P for trend =0.005). There was an increase of approximately 0.53 mg/dL in SUA per 1-fold increase in PrFV (β=0.53, 95%CI 0.02-1.04, P for nonlinearity = 0.637).

CONCLUSION

Our results confirmed a positive independent relationship between PrFV and SUA in Chinese adults. This study suggested that perirenal fat might constitute a potential risk factor for elevated serum uric acid levels.

Distribution and Associated Factors of Hepatic Iron-A Population-Based Imaging Study

Hepatic iron overload can cause severe organ damage; therefore, an early diagnosis and the identification of potential risk factors is crucial. We aimed to investigate the sex-specific distribution of hepatic iron content (HIC) in a population-based cohort and identify relevant associated factors from a panel of markers. We analyzed N = 353 participants from a cross-sectional sample (KORA FF4) who underwent whole-body magnetic resonance imaging. HIC was assessed by single-voxel spectroscopy with a high-speed T2-corrected multi-echo technique. A large panel of markers, including anthropometric, genetic, and laboratory values, as well as behavioral risk factors were assessed. Relevant factors associated with HIC were identified by variable selection based on LASSO regression with bootstrap resampling. HIC in the study sample (mean age at examination: 56.0 years, 58.4% men) was significantly lower in women (mean ± SD: 39.2 ± 4.1 s^-1) than in men (41.8 ± 4.7 s^-1, p < 0.001). Relevant factors associated with HIC were HbA1c as well as prediabetes for men and visceral adipose tissue as well as age for women. Hepatic fat, alcohol consumption, and genetic risk score for iron levels were associated with HIC in both sexes. In conclusion, there are sex-specific associations of HIC with markers of body composition, glucose metabolism, and alcohol consumption.

Association Between the Cardiometabolic Index and Hyperuricemia in an Asymptomatic Population with Normal Body Mass Index

Background and Purpose

The association between the cardiometabolic index (CMI) and hyperuricemia was investigated to provide theoretical support for the management of hyperuricemia in an asymptomatic population with normal body mass index (BMI).

Methods

A cross-sectional study was carried out among 374 asymptomatic adults with normal BMI. Traditional anthropometric indices and CMI were calculated. Anthropometric indices were divided into four quartiles and multivariate logistic analysis was used to analyze the association between these indices and hyperuricemia. Receiver operating characteristic (ROC) curves and area under the curve (AUC) were used to evaluate the power of the indices to predict hyperuricemia values. The DeLong test was used to compare the AUC of different anthropometric indices.

Results

After adjusting for confounding variables, the CMI exhibited a stronger association with hyperuricemia than other anthropometric indices. The odds ratio (OR) for hyperuricemia in the highest quartile of the CMI was 16.674 (confidence interval [CI]=4.424–62.846). The AUC of the CMI was 0.777 (95% CI=0.719–0.835, p<0.001), which was higher than the values for other anthropometric indices. The differences in AUC between the CMI and other indices were statistically significant; the optimal cutoff value of the CMI was 0.655, with sensitivity of 57.1% and specificity of 84.2%.

Conclusion

The CMI, which combines waist circumference, height and blood lipid parameters, was more strongly associated with hyperuricemia than other anthropometric indices in asymptomatic population with normal BMI. The CMI may serve as a potential monitoring indicator for hyperuricemia management in asymptomatic populations with normal BMI.

Serum uric acid is associated with incident metabolic syndrome independent of body shape index and body roundness index in healthy individuals

BACKGROUND AND AIMS

Elevated serum uric acid (SUA) levels, body shape index (BSI) and body roundness index (BRI) were associated with incident metabolic syndrome (MetS). We aimed to investigate the relationship among the SUA level, BSI, and BRI on the incidence of MetS.

METHODS AND RESULTS

We retrospectively included 6221 healthy individuals from annual health exams at our hospital between 2016/1/1 and 2016/12/31. We defined hyperuricemia as SUA levels greater than 7 mg/dl in men and 6 mg/dl in women and MetS according to the contemporary definition. The study cohort included 6221 healthy individuals with an overall incidence rate of MetS of 9.8%. Compared with the normouricemic group, the hyperuricemic group had a greater incidence of MetS (17.2% vs. 9.6%, P < 0.001). After full adjustment for confounders, the SUA level was significantly associated with incident MetS in addition to body mass index (BMI) (adjusted OR [aOR]: 1.161, 95% CI: 1.071-1.259, P < 0.001), BRI (aOR: 1.196, 95% CI: 1.104-1.296, P < 0.001), and BSI (aOR: 1.297, 95% CI: 1.200-1.403, P < 0.001). Regarding the anthropometric indices, BMI and BRI were independent predictors of incident MetS, but the BSI lost its significant association in multivariate logistic regression analyses. In sensitivity analyses, various thresholds of elevated SUA levels remained associated with incident MetS.

CONCLUSION

We showed a dose-response effect of SUA on incident MetS independent of BMI, BRI and BSI in healthy individuals. Future studies can use SUA levels to stratify cardiometabolic risk in healthy individuals.

CLINICAL TRIALS

ClinicalTrials.gov with the identification number NCT03473951.

Cardiometabolic health, visceral fat and circulating irisin levels: results from a real-world weight loss study

BACKGROUND

The aim of this pragmatic intervention study was to investigate changes in cardiometabolic outcomes, irisin plasma concentration, and body composition during a 4-month intervention in unselected obese individuals.

MATERIALS AND METHODS

In 111 obese women aged 36.73 ± 7.2 years, we measured changes in weight, lipid profiles, glucose, insulin, Homeostatic Model Assessment-Insulin Resistance Index (HOMA-IR), uric acid, aminotransferases, and irisin. Body composition including lean mass (LM) and total (TF), gynoid (GF), android (AF), and visceral fat (VF) was assessed using densitometry. Physical activity was assessed using the International Physical Activity Questionnaire (IPAQ). The participants received tailored written advice targeting lifestyle according to current guidelines. At follow-up, patients rated their adherence in the self-administered questionnaire.

RESULTS

Mean weight loss in the whole group was 3.12 kg (- 3.3%); 26% of the women achieved the desired target of weight loss (> 5% of the initial weight), whereas weight decreased moderately in 50% and increased in 14%. In 86 women with weight loss, there were significant changes in HOMA-IR (- 13.8%), insulin (- 11.2%), alanine aminotransferase (- 8.0%), VF (- 7.0%), AF (- 5.4%), TF (- 4.7%), GF (- 2.8%) and LM (- 1.5%), whereas irisin and HDL-C levels and the mean IPAQ score did not change.

CONCLUSIONS

In this real-world evidence study, a successful weight loss achieved only 26% of patients, with overall much better adherence to diet restriction than to exercise. However, even mild to moderate weight loss resulted in significant improvements in cardiometabolic health. Weight loss was associated with a modest LM decrease but did not influence plasma irisin.

Relationship between uric acid and lipid accumulation product index by gender in Korean adults: The 2016 Korean National Health and Nutrition Examination Survey

AIMS

The present study assesses the relationship between uric acid (UA) and lipid accumulation product index (LAP) by gender among Korean adults.

METHODS

Data from 5670 subjects (2463 men and 3207 women) in the Korean National Health and Nutrition Examination Survey (KNHANES VII-1) 2016 were analyzed. LAP was divided into four quartiles (Q1-Q4).

RESULTS

There were several key findings. Compared with Q1, in the overall population, the odds ratios (ORs) of hyperuricemia (UA ≥ 7.0 mg/dL in men or UA ≥ 6.0 mg/dL in women) were significantly higher in Q2 [1.847 (95% confidence interval [CI], 1.325-2.575)], Q3 [3.050 (95% CI, 2.216-4.198)], and Q4 of LAP [6.367 (95% CI, 4.658-8.704)]. In men, the ORs of hyperuricemia were significantly higher in Q2 [1.658 (95% CI, 1.162-2.367)], Q3 [2.341 (95% CI, 1.656-3.308)], and Q4 [4.633 (95% CI, 3.290-6.525)] than Q1. In women, the ORs of hyperuricemia were significantly higher in Q2 [2.254 (95% CI, 1.085-4.680)], Q3 [5.402 (95% CI, 2.735-10.668)], and Q4 [11.025 (95% CI, 5.620-21.628)] than Q1. In addition, UA levels were positively associated with LAP level in men (r = 0.218; p < 0.001), women (r = 0.261; p < 0.001), and the overall population (r = 0.260; p < 0.001).

CONCLUSIONS

Hyperuricemia was positively associated with LAP in Korean men and women.

Association of Metabolically Healthy and Unhealthy Obesity Phenotypes with Oxidative Stress Parameters and Telomere Length in Healthy Young Adult Men. Analysis of the MAGNETIC Study

Obesity is a significant factor related to metabolic disturbances that can lead to metabolic syndrome (MetS). Metabolic dysregulation causes oxidative stress, which affects telomere structure. The current study aimed to evaluate the relationships between telomere length, oxidative stress and the metabolically healthy and unhealthy phenotypes in healthy young men. Ninety-eight participants were included in the study (49 healthy slim and 49 obese patients). Study participants were divided into three subgroups according to body mass index and metabolic health. Selected oxidative stress markers were measured in serum. Relative telomere length (rTL) was measured using quantitative polymerase chain reaction. The analysis showed associations between laboratory markers, oxidative stress markers and rTL in metabolically healthy and unhealthy participants. Total oxidation status (TOS), total antioxidant capacity (TAC) and rTL were significantly connected with metabolically unhealthy obesity. TAC was associated with metabolically healthy obesity. Telomeres shorten in patients with metabolic dysregulation related to oxidative stress and obesity linked to MetS. Further studies among young metabolically healthy and unhealthy individuals are needed to determine the pathways related to metabolic disturbances that cause oxidative stress that leads to MetS.

Correlation Between Serum Uric Acid and Body Fat Distribution in Patients With Polycystic Ovary Syndrome

OBJECTIVE

This study aims to investigate the correlation between serum uric acid levels and body fat distribution in patients with polycystic ovary syndrome (PCOS).

METHODS

Between May 2017 and March 2021, a total of 199 patients with PCOS were recruited from the Department of Endocrinology and Metabolism at the Shanghai Tenth People's Hospital. Anthropometric characteristics, metabolic parameters, and reproductive hormones were measured. Hyperuricemia was defined as serum uric acid (SUA) greater than 420 μmol/l. Dual-energy X-ray absorptiometry (DEXA) was used to measure body fat distribution.

RESULTS

The prevalence of hyperuricemia in patients with PCOS was 28.64%. PCOS patients with hyperuricemia are more obese and have a higher waist-to-hip ratio (WHR) and worse lipid metabolism than those without hyperuricemia. According to SUA quartiles, patients in the highest quartile had higher total testosterone (TT), body fat accumulation, and lower sex hormone-binding globulin (SHBG) than patients in the lowest quartile. SUA was correlated with percentage of total body fat, arm fat mass, leg fat mass, trunk fat mass, android/gynoid (A/G) ratio, and visceral adipose tissue (VAT) mass. After controlling possible confounders, logistic regression analysis found that only excessive VAT mass could significantly increase the risk of hyperuricemia in patients with PCOS.

CONCLUSION

In patients with PCOS, a high level of VAT mass, but not other fat compartments, will exacerbate the risk of hyperuricemia. Attention should be paid to the role of excessive VAT in the occurrence and development of PCOS with hyperuricemia.

Decrease in Serum Urate Level Is Associated With Loss of Visceral Fat in Male Gout Patients

OBJECTIVE

To clarify the relationship between serum urate (SU) decrease and visceral fat area (VFA) reduction in patients with gout.

METHODS

We retrospectively analyzed 237 male gout patients who had two sets of body composition and metabolic measurements within 6 months. Subjects included had all been treated with urate-lowering therapy (ULT) (febuxostat 20-80 mg/day or benzbromarone 25-50 mg/day, validated by the medical record). All patients were from the specialty gout clinic of The Affiliated Hospital of Qingdao University. The multiple linear regression model evaluated the relationship between change in SU [ΔSU, (baseline SU) - (final visit SU)] and change in VFA [ΔVFA, (baseline VFA) - (final visit VFA)].

RESULTS

ULT resulted in a mean (standard deviation) decrease in SU level (464.22 ± 110.21 μmol/L at baseline, 360.93 ± 91.66 μmol/L at the final visit, p <0.001) accompanied by a decrease in median (interquartile range) VFA [97.30 (81.15-118.55) at baseline, 90.90 (75.85-110.05) at the final visit, p < 0.001]. By multiple regression model, ΔSU was identified to be a significant determinant variable of decrease in VFA (beta, 0.302; p = 0.001).

CONCLUSIONS

The decrease in SU level is positively associated with reduced VFA. This finding provides a rationale for clinical trials to affirm whether ULT promotes loss of visceral fat in patients with gout.

Serum Uric Acid Levels and Metabolic Indices in an Obese Population: A Cross-Sectional Study

OBJECTIVE

To analyze the association between serum uric acid (SUA) and metabolic state in obese inpatients and preliminarily explore potential mechanisms of hyperuricemia in obesity.

METHODS

A total of 153 obese inpatients were selected and assigned based on SUA level to the normal uric acid (NC group) or high uric acid (HUA) group. Patients' sex, age, height, weight, blood pressure, BMI, and prevalence of metabolic syndrome were collected and recorded. SUA, FPG, FIns, HOMA-IR, HOMA-IS, HbA_1c, TGs, TC, LDL-C, and HDL-C levels were tested. Pearson correlation analysis was performed to analyze the correlation between SUA and related metabolic indicators. Logistic regression was performed to analyze independent risk factors of hyperuricemia in obesity.

RESULTS

In the HUA group, the patients were predominantly males, and BMI, DBP, TGs, FPG, FIns, HOMA-IR, HOMA-IS, and metabolic syndrome were higher than those in the NC group (P<0.05), while HDL-C was lower than that in the NC group (P<0.05). There were no significant differences between the groups in TC or LDL-C. Pearson correlation analysis showed that in obese patients, SUA was positively correlated with BMI, FIns, HOMA-IR, HOMA-IS, TGs, andmetabolic syndrome and negatively correlated with age and HDL-C. Logistic regression showed that BMI, hyperinsulinemia, and insulin resistance were independent risk factors of hyperuricemia.

CONCLUSION

Development of hyperuricemia in obese populations might be correlated with hyperinsulinemia or insulin resistance.

Fat-Free Mass Is Better Related to Serum Uric Acid Than Metabolic Homeostasis in Prader-Willi Syndrome

Background: Prader-Willi syndrome (PWS) is conventionally regarded as a model of genetic obesity carrying a metabolically healthier profile and fat compartmentalization than subjects with non-syndromic obesity. Serum uric acid (sUA) is a recognized surrogate marker of metabolic derangement. As no information is currently available on sUA levels in adults with PWS, we aimed to analyze sUA in a large cohort of adult patients with PWS in comparison to a control counterpart; secondly, we aimed to investigate the metabolic and non-metabolic determinants of sUA in PWS. Methods: A cross-sectional study was conducted on 89 consecutive adult patients with genetically confirmed PWS spanning a wide BMI range (17.2–56.7 kg/m²). As controls, 180 age-, sex- and BMI-matched healthy controls were included. sUA levels were analyzed in relation to the PWS status, metabolic variables, hormone status, body composition, and resting energy expenditure (REE). Bivariate correlation and multivariable regression studies were used to test for predictors of sUA in PWS. Results: Despite having similar BMI values, patients with PWS presented with higher FM (p < 0.0001), lower FFM (p < 0.0001) and REE values than controls (p < 0.0001). In PWS, sUA levels were non-significantly different between subjects with and without obesity (5.4 ± 1.3 vs. 4.9 ± 1.1 mg/dL, p = 0.09), and did not vary significantly in relation to genotype, sex steroid or GH replacement, as well as psychiatric treatments. Rates of hyperuricaemia (19.1% vs. 33.7%, p < 0.01) and absolute sUA levels were lower in patients with PWS compared to controls owing to significant differences between subgroups with obesity (5.5 ± 1.4 vs. 6.6 ± 1.6 mg/dL, p < 0.0001). In merged populations, sUA increased in parallel with age, BMI, FM, FFM, REE, glucolipid homeostasis, and inflammatory markers. In a separate analysis in PWS, however, sUA correlations with BMI, FM, and inflammatory markers were null. Stepwise multivariable regression analysis in the PWS group adjusted for karyotype, age, sex, FM, FFM, obesity, triglycerides, and HDL cholesterol, showed that sUA levels were independently associated with FFM (β = 0.35, p < 0.0001) and, albeit less significantly, with triglycerides (β = 0.23, p < 0.05). The introduction of height-normalized FFM (FFM index) in the regression model, however, abrogated the predictive role of FFM on sUA. Conclusions: FFM mass is a strong predictor of sUA. PWS is associated to lower sUA levels than controls likely due to genetic predisposition to different body composition and healthier metabolic phenotype. Further studies are warranted to assess purine metabolism and the clinical significance of the FFM index in PWS.