Association between anemia and hyperuricemia: results from the Korean National Health and Nutrition Examination Survey

The Association of Serum Uric Acid with Risk of Obstructive Sleep Apnea: The Korean National Health and Nutrition Examination Survey 2019-2021

Upper airway collapse and apneas in obstructive sleep apnea (OSA) induce intermittent hypercapnia and hypoxia, eventually contributing to excessive uric acid production. This study aimed to evaluate the association between hyperuricemia and OSA in the general population via analysis of the eighth KNHANES dataset (2019-2021). OSA risk was identified via the STOP-Bang questionnaire, with a score ≥3 indicating high risk. Among 11,981 total participants, 4572 (38.2%) had a high OSA risk. Participants with a high OSA risk had higher uric acid levels compared to those with a low risk (5.5 ± 1.4 mg/dL vs. 4.8 ± 1.2 mg/dL, p < 0.001). Serum uric acid levels were positively correlated with STOP-Bang score (r: 0.317, p < 0.001). Multivariate analysis revealed that hyperuricemia was associated with a high OSA risk after adjusting for confounders (odds ratio: 1.30, 95%CI: 1.11-1.53, p = 0.001). Therefore, serum uric acid levels are significantly higher in those with a high OSA risk and correlate with the risk of OSA. Further, hyperuricemia is an independently associated risk factor for high OSA risk. More research is warranted to evaluate the long-term clinical outcomes of hyperuricemia in OSA and to determine whether treatment targeting hyperuricemia is effective in the clinical course of OSA.

GBA1 as a risk gene for osteoporosis in the specific populations and its role in the development of Gaucher disease

BACKGROUND

Osteoporosis and its primary complication, fragility fractures, contribute to substantial global morbidity and mortality. Gaucher disease (GD) is caused by glucocerebrosidase (GBA1) deficiency, leading to skeletal complications. This study aimed to investigate the impact of the GBA1 gene on osteoporosis progression in GD patients and the specific populations.

METHODS

We selected 8115 patients with osteoporosis (T-score ≤ - 2.5) and 55,942 healthy individuals (T-score > - 1) from a clinical database (N = 95,223). Monocytes from GD patients were evaluated in relation to endoplasmic reticulum (ER) stress, inflammasome activation, and osteoclastogenesis. An in vitro model of GD patient's cells treated with adeno-associated virus 9 (AAV9)-GBA1 to assess GBA1 enzyme activity, chitotriosidase activity, ER stress, and osteoclast differentiation. Longitudinal dual-energy X-ray absorptiometry (DXA) data tracking bone density in patients with Gaucher disease (GD) undergoing enzyme replacement therapy (ERT) over an extended period.

RESULTS

The GBA1 gene variant rs11264345 was significantly associated [P < 0.002, Odds Ratio (OR) = 1.06] with an increased risk of bone disease. Upregulation of Calnexin, NOD-, LRR- and pyrin domain-containing protein 3 (NLRP3) and Apoptosis-associated speck-like protein containing a C-terminal caspase recruitment domain (ASC) was positively associated with osteoclastogenesis in patients with GD. In vitro AAV9-GBA1 treatment of GD patient cells led to enhanced GBA1 enzyme activity, reduced chitotriosidase activity, diminished ER stress, and decreased osteoclast differentiation. Long-term bone density data suggests that initiating ERT earlier in GD leads to greater improvements in bone density.

CONCLUSIONS

Elevated ER stress and inflammasome activation are indicative of osteoporosis development, suggesting the need for clinical monitoring of patients with GD. Furthermore, disease-associated variant in the GBA1 gene may constitute a risk factor predisposing specific populations to osteoporosis.

Increased prevalence of periodontitis with hypouricemic status: findings from the Korean National Health and Nutrition Examination Survey, 2016-2018

PURPOSE

The aim of this study was to investigate the relationship between serum uric acid (SUA) levels and the risk of periodontitis in Korean adults using data from the Korean National Health and Nutrition Examination Survey (KNHANES).

METHODS

This cross-sectional study used data from the KNHANES 2016-2018 and analysed 12,735 Korean adults aged ≥19 years who underwent oral examinations. Hypouricemia was defined as SUA <3 mg/dL in men and <2 mg/dL in women, and hyperuricemia was defined as SUA ≥7 mg/dL in men and ≥6 mg/dL in women.

RESULTS

The weighted prevalence of hypouricemia and hyperuricemia was 0.6% and 12.9%, respectively. The overall weighted periodontitis rate was 30.5%. The frequency of periodontitis in subjects with hypouricemia, normouricemia, and hyperuricemia were 51.1%, 30.3%, and 30.6%, respectively. Study participants with hypouricemia were significantly older, had significantly fasting blood glucose levels, and had better kidney function than non-hypouricemic participants. In univariate logistic regression analyses, hypouricemia was associated with periodontitis, but hyperuricemia was not. The fully adjusted model revealed that the adjusted odds ratio of hypouricemia for periodontitis was 1.62 (95% confidence interval, 1.13-2.33), while the relationship between hyperuricemia and periodontitis in the multivariable logistic regression model was not significant.

CONCLUSIONS

The results of this study suggest that hypouricemia is associated with an increased risk of periodontitis.

Association of serum uric acid with anemia in U.S. adults: a cross-sectional study using secondary data

BACKGROUND

High serum uric acid (SUA) is a risk factor of cardiovascular disease (CVD). Abnormal SUA have been correlated with a significant increase in mortality. Anemia is an independent predictor of mortality and CVD. To date, no study has investigated the relationship between SUA and anemia. Here, we explored the correlation between SUA and anemia in the American population.

METHODS

The cross-sectional study involved 9205 US adults from NHANES (2011-2014). The relationship between SUA and anemia was explored using multivariate linear regression models. Two-piecewise linear regression model, generalized additive models (GAM) and smooth curve fitting were performed to explore the non-linear relationships between SUA and anemia.

RESULTS

We found a U-shaped non-linear relationship between SUA and anemia. The inflection point of the SUA concentration curve was 6.2 mg/dL. The ORs (95% CIs) for anemia on the left and right of the inflection point were 0.86 (0.78-0.95) and 1.33 (1.16-1.52), respectively. The 95% CI of inflection point was 5.9-6.5 mg/dL. The findings showed that both genders presented a U-shaped correlation. Safe ranges of SUA in men and women were 6-6.5 and 4.3-4.6 mg/dL, respectively.

CONCLUSIONS

Both high and low SUA levels were correlated with increased risk of anemia, and a U-shaped relationship was observed between SUA and anemia.

The relationship between anemia and hyperuricemia and hypertension in Korean adults: the Korea National Health and Nutrition Examination Survey 2016-2018

OBJECTIVE

It is unclear whether uric acid (UA) has a negative or positive effect on anemia, and this may vary depending on the presence or absence of chronic disease such as hypertension (HTN). The present study was conducted to assess the relationship between anemia and hyperuricemia in Korean adults with or without hypertension.

METHODS

Data from 16,740 adults (age ≥20 years) in the Korean National Health and Nutrition Examination Survey (2016 - 2018) were analyzed.

RESULTS

Several key findings were identified. First, after adjusting for the related variables in the non-HTN group, the odds ratio (OR) of anemia (hemoglobin [Hb] ≥ 13.0 mg/dL in men and ≥12.0 mg/dL in women), using the normouricemia (UA < 7.0 mg/dL in men and UA < 6.0 mg/dL in women) as a reference, was inversely significant for the hyperuricemia (UA ≥ 7.0 mg/dL in men and ≥6.0 mg/dL in women) in the overall population (OR, 0.589; 95% confidence interval [CI], 0.409-0.848) and women (OR, 0.575; 95% CI, 0.363-0.909) but not in men (OR, 0.836; 95% CI, 0.441-1.586). Second, after adjusting for the related variables in the HTN group, the OR of anemia, using the normouricemia as a reference, was positively significant for the hyperuricemia in the overall population (OR, 1.501; 95% CI, 1.167-1.930), men (OR, 1.706; 95% CI, 1.154-2.523), and women (OR, 1.512; 95% CI, 1.079-2.210).

CONCLUSIONS

Hyperuricemia was positively associated with anemia in men and women with HTN. Hyperuricemia was inversely associated with anemia in women without HTN but not in men without HTN.

The relationship between hyperuricemia and anemia and metabolic syndrome in Korean adults: The Korea National Health and Nutrition Examination Survey 2019

AIM

The present study was conducted to assess the relationship between hyperuricemia and anemia in Korean adults with or without metabolic syndrome (MetS).

METHODS

Data from 6073 adults (age ≥ 20 years) in the Eighth Korean National Health and Nutrition Examination Survey (2019) were analyzed.

RESULTS

Several key findings were identified. First, after adjusting for the related variables, the hemoglobin [Hb] level in the hyperuricemia subgroup (uric acid [UA] ≥ 7.0 mg/dL in men or ≥ 6.0 mg/dL in women) was higher than in the normouricemia subgroup (UA < 7.0 mg/dL in men or < 6.0 mg/dL in women) in subjects with non-MetS (p = 0.005), whereas it was lower than in the normouricemia subgroup in subjects with MetS (p = 0.032). Second, after adjusting for the related variables, the odds ratio (OR) of anemia (Hb < 13.0 g/dL in men or < 12 g/dL in women), using the normouricemia subgroup as a reference, was negatively significant for the hyperuricemia subgroup in subjects with non-MetS (OR, 0.478; 95 % CI, 0.300-0.761) but positively significant for the hyperuricemia subgroup in subjects with MetS (OR, 1.765; 95 % CI, 1.160-2.198).

CONCLUSIONS

Hyperuricemia was associated with a decrease in anemia in non-MetS but an increase in anemia in MetS.

Synergetic Association between Anemia and Hyperuricemia on New-Onset Chronic Kidney Disease in a Large Taiwanese Population Follow-Up Study

The incidence of chronic kidney disease (CKD) is increasing worldwide; however, the association between CKD and anemia and hyperuricemia has yet to be clarified. In addition, whether anemia and hyperuricemia only influence renal damage in combination with other comorbidities or whether they are direct causative factors is also controversial. Therefore, the aim of this longitudinal study was to investigate these issues in a large Taiwanese cohort. We enrolled 26,631 participants from the Taiwan Biobank (TWB) after excluding those with CKD at the baseline, all of whom had follow-up data for a median of 4 years. In this study, CKD was defined as an estimated glomerular filtration rate < 60 mL/min/1.73 m2, incident new-onset CKD was defined as the development of CKD during follow-up, anemia was defined as a hemoglobin level <13 mg/dL in males and <12 mg/dL in females, and hyperuricemia was defined as a serum uric acid (UA) level >7 mg/dL in males and >6 mg/dL in females. The participants were divided into four groups according to whether or not they had anemia and hyperuricemia. Multivariable analysis showed that low hemoglobin (per 1 g/dL; odds ratio [OR], 0.760; p < 0.001) and high serum UA (per 1 mg/dL; OR, 1.444; p < 0.001) in model 1 and anemia (OR, 2.367; p < 0.001) and hyperuricemia (OR, 2.516; p < 0.001) in model 2 were significantly associated with new-onset CKD. Furthermore, compared to the group without anemia or hyperuricemia, the groups with anemia without hyperuricemia (OR, 2.502; p < 0.001), without anemia with hyperuricemia (OR, 2.559; p < 0.001), and with anemia and hyperuricemia (OR, 5.505; p < 0.001) were significantly associated with new-onset CKD. There was a significant interaction between hemoglobin and serum UA and new-onset CKD (p < 0.001). In conclusion, we found that anemia and hyperuricemia were associated with new-onset CKD, respectively, and also had a synergetic effect on new-onset CKD.

Comparison of 3 hyperuricemia mouse models and evaluation of food-derived anti-hyperuricemia compound with spontaneous hyperuricemia mouse model

Hyperuricemia animal models have long been used for evaluating food-derived anti-hyperuricemia compounds. Fructose and potassium oxonate are commonly used for developing hyperuricemia mouse model. Recent research also developed spontaneous hyperuricemia model by uricase knockout (Uox^-/-). In this work, we evaluated 3 kinds of models with the same gene background to illustrate the differences between the treatments. Unlike the uric acid levels in potassium oxonate (224.79 ± 33.62 μmol/L) and Uox^-/- groups (458.39 ± 38.29 μmol/L), fructose treatment did not lead to higher serum uric acid level (174.93 ± 30.46 μmol/L) comparing to the control group (153.53 ± 40.96 μmol/L). However, abnormal glycometabolism only developed in the fructose and the Uox^-/- group. In addition, anemia, inflammasome and severe renal injury occurred in the Uox^-/- group. The Uox^-/- mice were then treated with puerarin and allopurinol, and found that puerarin could reduce serum uric acid and alleviated the serious renal damage associated with high uric acid. Thus, the Uox^-/- mice could be a suitable model for screening and evaluating anti-hyperuricemia compounds.

Risk Factors for Postsurgical Gout Flares after Thoracolumbar Spine Surgeries

Gouty arthritis is the most common form of inflammatory arthritis and flares frequently after surgeries. Such flares impede early patient mobilization and lengthen hospital stays; however, little has been reported on gout flares after spinal procedures. This study reviewed a database of 6439 adult patients who underwent thoracolumbar spine surgery between January 2009 and June 2021, and 128 patients who had a history of gouty arthritis were included. Baseline characteristics and operative details were compared between the flare-up and no-flare groups. Multivariate logistic regression was used to analyze predictors and construct a predictive model of postoperative flares. This model was validated using a receiver operating characteristic (ROC) curve analysis. Fifty-six patients (43.8%) had postsurgical gout flares. Multivariate analysis identified gout medication use (odds ratio [OR], 0.32; 95% confidence interval [CI], 0.14−0.75; p = 0.009), smoking (OR, 3.23; 95% CI, 1.34−7.80; p = 0.009), preoperative hemoglobin level (OR, 0.68; 95% CI, 0.53−0.87; p = 0.002), and hemoglobin drop (OR, 1.93; 95% CI, 1.25−2.96; p = 0.003) as predictors for postsurgical flare. The area under the ROC curve was 0.801 (95% CI, 0.717−0.877; p < 0.001). The optimal cut-off point of probability greater than 0.453 predicted gout flare with a sensitivity of 76.8% and specificity of 73.2%. The prediction model may help identify patients at an increased risk of gout flare.

Biomarkers of iron status in allopurinol-treated renal stone patients

Limited evidence exists on the effect of xanthine oxidase inhibitors in nephrolithiasis patients on iron status markers, beyond their effects on urate. The aim of this study was to investigate whether allopurinol therapy was associated with a significant impact on parameters related to iron status, in patients with renal stones. Allopurinol treatment was associated with a nonsignificant decline in serum uric acid. There were no significant differences in serum levels of transferrin and ferritin after treatment with allopurinol compared to pre-treatment levels. A non-significant fall in serum levels of haptoglobin was registered. The drug was associated with a significant rise in serum iron levels. Serum uric acid and iron did not show a significant correlation with any parameter in the study. Allopurinol exerted an overall non-significant effect on iron metabolism in nephrolithiasis patients, save for serum iron, this entails lack of untoward effects in populations with-iron related conditions.

Is there any association between contrast-induced nephropathy and serum uric acid levels?

Introduction: During the recent years, several studies have investigated that hyperuricemia is associated with greater incidence of contrast induced nephropathy (CIN). Most of them are in acute conditions like primary percutaneous coronary interventions. This study aimed to assess the relationship between high serum uric acid and incidence of acute kidney injury in patients undergoing elective angiography and angioplasty.

Methods: This prospective study was conducted on 211 patients who were admitted to hospital for elective coronary angiography or angioplasty. The researchers measured serum creatinine and uric acid on admission and repeated creatinine measurement in 48 hours and seven days after the procedure. According to serum uric acid, the patients were divided into two groups; group 1 with normal uric acid and group 2 with hyperuricemia which was defined as uric acid more than 6 mg/dL in women and 7 mg/dL in men. CIN is defined as an increased creatinine level of more than 0.5 mg/dL or 25% from the baseline in 48 hours after the intervention.

Results: In total, 211 patients with mean age of 60.58 years were enrolled in the study. Of these, 87 (41.2%) patients were in the high uric acid group and 124 (58.8%) were in the normal uric acid group. CIN was occurred in 16 patients (7.5%). Seven out of 16 (8.04%) were in the high uric acid and nine (7.2%) were in the normal uric acid group. There were no significant differences between the two groups (P =0.831).

Conclusion: The frequency of CIN development was not different in the patients with hyperuricemia.