Association between serum uric acid concentrations and grip strength: Is there effect modification by age?

The agreement of low lean mass with obesity using different definitions and its correlation with hyperuricemia

Background

The agreement on the identification of sarcopenic obesity remains elusive, and its association with hyperuricemia remains unestablished. This study sought to evaluate the agreement of low lean mass (LLM) with obesity and its correlation with hyperuricemia.

Methods

A total of 25,252 study participants, comprising 4,597 individuals with hyperuricemia, were obtained from the National Health and Nutrition Examination Survey spanning the years 1999-2006 and 2011-2018. LLM with obesity was characterized by the coexistence of LLM, determined by the ratio of appendicular lean mass to body mass index (BMI), and three categories of obesity including BMI, body fat percentage (BF%), and waist circumference (WC). We employed Cohen's kappa to evaluate the agreement among the different diagnostic criteria and implemented survey multiple logistic regression and stratified analyses to explicate the connection between LLM with obesity and the risk of hyperuricemia.

Results

When defining obesity using BF%, BMI, and WC, the prevalence of LLM with obesity varied from 6.6 to 10.1%, with moderate-to-strong agreement. In the fully adjusted model, individuals with LLM or any of the three types of obesity exhibited notably elevated odds of developing hyperuricemia. Likewise, participants with LLM and obesity had 2.70 (LLM + BMI), 2.44 (LLM + BF%), and 3.12 (LLM + WC) times the risk of hyperuricemia, respectively, compared with healthy individuals. The association between LLM with obesity and hyperuricemia remained stable and significant across different age and sex subgroups.

Conclusion

When employing the three definitions of obesity, the incidence of LLM with obesity was not high, and the diagnostic agreement was relatively good. The participants with LLM and obesity exhibited an increased risk of hyperuricemia.

Serum uric acid levels and health outcomes in CKD: a prospective cohort study

BACKGROUND

Hyperuricemia is prevalent in individuals with chronic kidney disease (CKD). Elevated serum uric acid (SUA) concentrations have been considered an independent risk factor for the onset of CKD. However, the relationship between SUA concentrations and long-term health outcomes among patients with CKD remains unclear.

METHODS

We performed a prospective cohort study with nationally representative sample to investigate the relationship between SUA concentrations and mortality risk including all-cause, cardiovascular disease (CVD) and cancer mortality, among patients with CKD. The weighted restricted cubic spline analyses combined with the multivariate-adjusted Cox proportional hazard models were used to test the nonlinearity of relationship.

RESULTS

The 6642 patients participating in National Health and Nutrition Examination Survey 1999-2018 were enrolled. During 656 885 person-months of follow-up time, 2619 all-cause deaths were recorded, including 1030 CVD deaths and 458 cancer deaths. Our study presented J-shaped non-linear relationships between SUA concentrations and all-cause and CVD mortality with inflection points at 311.65 μmol/L and 392.34 μmol/L, respectively. When SUA concentration was higher than those inflection points, every increase of 50 μmol/L SUA was associated with 11.7% and 17.0% greater multivariable-adjusted hazard ratio of all-cause and CVD mortality, respectively. In addition, a negative linear correlation with cancer mortality was detected.

CONCLUSION

These findings suggested that maintaining appropriate SUA concentrations may improve long-term health outcomes among CKD patients. The corresponding inflection points of J-shaped non-linear relationships were 311.65 and 392.34 μmol/L for all-cause and CVD mortality. Further clinical trials are required to investigate uric acid-lowering targets.

Association between serum copper, zinc and their ratio and handgrip strength among adults: a study from National Health and Nutrition Examination Survey (NHANES) 2011-2014

Evidence for the association between serum copper and zinc status and handgrip strength is very limited only in several observational studies with study participants of specific population or a narrower age range. The aim of this study was to evaluate the association between serum copper, zinc and their ratio and handgrip strength in the general population. This study included adult participants aged 20-80 years with complete data of serum copper and zinc status and handgrip strength from NHANES 2011-2014. Handgrip strength was calculated as the average of the maximum measure obtained in each hand with a grip strength dynamometer and corrected using BMI. Serum copper and zinc levels were measured using inductively coupled plasma dynamic reaction cell mass spectrometry, and their ratios were calculated. The multivariable linear regression and restricted cubic spline models were used. Serum copper level was inversely associated with BMI-corrected handgrip strength, and the beta coefficients (95% confidence intervals) comparing the second, third, and fourth to the lowest quartiles of serum copper level were - 0.17 kg (- 0.26; - 0.08), - 0.22 kg (- 0.32; - 0.13), and - 0.36 kg (- 0.44; - 0.28), respectively (P for trend < 0.001). Non-linear association was detected between serum copper level and BMI-corrected handgrip strength (P < 0.01). Consistent with serum copper, serum copper/zinc ratio was inversely associated with BMI-corrected handgrip strength. However, no significant associations were observed between serum zinc level and BMI-corrected handgrip strength (all P > 0.05). Higher serum copper level and copper/zinc ratios were significantly associated with lower handgrip strength. Further research is needed to address related issues.

Serum uric acid is not associated with appendicular muscle mass index in young and middle-aged adults: Results from NHANES 2011-2012

BACKGROUND

Recent studies have evaluated the association between uric acid (UA) and muscle mass in older adults; however, little is known about this relationship in young and middle-aged individuals. Our aim was to investigate whether serum UA is associated with appendicular muscle mass index (AMMI) in young and middle-aged individuals. We also aimed to evaluate whether this association is sex-specific.

METHODS

A cross-sectional study was performed with young and middle-aged individuals aged from 20 to 59 years from National Health and Nutrition Examination Survey (NHANES) 2011-2012. A total of 2255 individuals (1440 young and 815 middle-aged individuals; 1167 men and 1088 women) were evaluated. Body composition was assessed by Dual Energy X-ray absorptiometry (DXA) and AMMI was calculated using the arms plus legs lean mass divided by the height squared. UA levels were measured by colorimetric method. Regression analyzes were performed to evaluate whether AMMI is associated with the tertiles of UA levels after adjustments for potential confounders.

RESULTS

In the unadjusted analyzes, serum UA was positively associated with AMMI for total sample, young, and middle-aged individuals of both sexes. However, after adjustments for confounders, UA levels were no longer associated with AMMI independent of the age-rage and sex.

CONCLUSION

Serum UA is not associated with AMMI in young or middle-aged individuals independent of the sex.

Association between serum uric acid and relative hand grip strength in comparison with metabolic syndrome components

Objectives

To investigate the association between serum uric acid (UA) and relative hand grip strength (HGS) in comparison with metabolic syndrome components.

Methods

We analyzed the data of 5247 Korean adults aged ≥ 20 years (2422 men and 2825 women) who participated in the KNHNES VII (2018).

Results

Among women, relative HGS was significantly lower in participants with hyperuricemia (1.65 ± 0.04) than in those without (1.95 ± 0.01) and was significantly decreased in the highest quartile (4Q: 1.77 ± 0.02) of serum UA compared with that in the lowest quartile (1Q: 1.98 ± 0.02). Among men, relative HGS was lower in participants with hyperuricemia (3.09 ± 0.04 vs. 3.16 ± 0.02) and decreased in 4Q (3.08 ± 0.03) of serum UA compared with that in 1Q (3.15 ± 0.03); however, these results were not statistically significant. In age- and multivariate-adjusted analyses in men, relative HGS was significantly lower in 4Q compared with that in 1Q in model 1 (adjusted for age), but there were no significant differences in model 2 (adjusted for age, BMI, and waist circumference) and model 3 (adjusted for age, BMI, waist circumference, systolic and diastolic blood pressure, fasting blood glucose, triglycerides, and high-density lipoprotein cholesterol). Meanwhile, in women, relative HGS was significantly decreased in 4Q compared with that in 1Q in all models.

Conclusions

A significant inverse correlation was observed between serum UA levels and relative HGS in women, and their significance was maintained even after adjusting for age and metabolic syndrome components.

Muscle Fat Content Is Strongly Associated With Hyperuricemia: A Cross-Sectional Study in Chinese Adults

Studies have indicated that the skeletal muscle mass and strength was related to serum uric acid (UA), but there is a lack of research on the association of skeletal muscle fat content with UA. The purpose of this cross-sectional study is to investigate the correlation of skeletal muscle fat index (SMFI) and hyperuricemia (HUA) in Chinese adults. 500 subjects (306 men and 194 women) were included in the study. The participants were divided into four groups according to SMFI quartiles. Pearson's correlations between SMFI and metabolic variables were calculated. Logistic regression analysis was used to estimate the association between the quartiles of SMFI and risk of hyperuricemia. UA showed a positive association with SMFI after adjusted for BMI, age and gender. A significant association between the SMFI and risk of HUA was found, the OR for HUA was 2.79 (95% CI 1.18-6.59, p<0.05) in Q2, 2.41(95% CI 1.00-5.81, p<0.05) in Q3, and 2.63 (95% CI 1.03-6.72, p<0.05) in Q4, after adjusted for BMI. In conclusion, the SMFI was significantly associated with the level of serum UA, and the higher SMFI may indicate a higher risk of HUA, independent of BMI.

Serum uric acid is positively associated with muscle strength in older men and women: Findings from NHANES 1999-2002

BACKGROUND

One of the causes of strength loss in older adults is the increased oxidative stress; thus, substances with antioxidants properties may have protective effects on muscle strength. Uric acid (UA) is an important antioxidant and it seems to be positively associated with muscle strength in older adults; however, the current evidence is still limited.

AIM

To investigate whether serum UA is associated with muscle strength in older men and women.

METHODS

A cross-sectional study was performed evaluating older adults aged from 50 to 85 years from National Health and Nutrition Examination Survey (NHANES) 1999-2000 and 2001-2002. A total of 2361 individuals (1256 men and 1105 women) were evaluated. The peak isokinetic knee extensor strength was assessed by kinetic communicator isokinetic dynamometer; while UA levels were measured by colorimetric method. Linear regression analyses were performed to estimate the coefficients and 95% confidence intervals for muscle strength by quintiles of UA levels, adjusted for potential confounders.

RESULTS

In the unadjusted analyses, serum UA was positively associated with peak force in men and total sample, but not in women. However, after adjustments for confounders, UA levels were positively associated with peak force in total sample (p-trend = 0.007), men (p-trend = 0.044) and women (p-trend = 0.016).

CONCLUSION

Serum UA is positively associated with muscle strength in older men and women. These results suggest that UA levels seem to be a protective factor for muscle strength in older adults independent of the sex.

Associations between Health-Related Physical Fitness and Cardiovascular Disease Risk Factors in Overweight and Obese University Staff

PURPOSE

This cross-sectional study examined the associations between health-related physical fitness (HPF) and cardiovascular disease (CVD) risk factors in overweight and obese university staff.

METHODS

A total of 340 university staff (109 women, mean age 43.1 ± 9.7 years) with overweight (n = 284) and obesity (n = 56) were included. The HPF indicators included skeletal muscle mass index (SMI), body fat percentage (BFP), grip strength (GS), sit-and-reach test (SRT), and vital capacity index (VCI). CVD risk factors were measured, including uric acid (UA), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and glucose (GLU).

RESULTS

BFP, SMI, and GS were positively associated with UA level (β = 0.239, β = 0.159, β = 0.139, p < 0.05). BFP was positively associated with TG and TG/HDL-C levels (β = 0.421, β = 0.259, p < 0.05). GS was positively associated with HDL-C level (β = 0.244, p < 0.05). SRT was negatively associated with GLU level (β = -0.130, p < 0.05).

CONCLUSIONS

In overweight and obese university staff, body composition, muscle strength, and flexibility were associated with CVD risk factors. An HPF test may be a practical nonmedical method to assess CVD risk.

Effect of hyperuricemia on functional outcomes and complications in patients with elbow stiffness after open arthrolysis combined with hinged external fixation: a retrospective study

BACKGROUND

Hyperuricemia is considered a risk factor for increased postoperative complications and adverse functional outcomes in a variety of orthopedic surgeries. The purpose of this retrospective study was to investigate the clinical efficacy of patients with different uric acid levels after elbow arthrolysis.

METHODS

The study included 131 patients with post-traumatic elbow stiffness who underwent arthrolysis between March 2014 and March 2016. All patients were divided into 4 groups based on the preoperative serum level of uric acid (UA). The quartile method was used for grouping patients, including 33 in Q1 (UA <293 μmol/L), 34 in Q2 (293-348 μmol/L), 32 in Q3 (348-441 μmol/L), and 32 in Q4 (441-710 μmol/L). At baseline and each time point of follow-up, functional performance, Mayo Elbow Performance Score, visual analog scale for pain, and complications were evaluated.

RESULTS

Preoperative data were not significantly different among the 4 groups (Q1, Q2, Q3, and Q4). At the final follow-up, the following data showed significant differences among the 4 groups: extension (P = .031), flexion (P = .008), range of motion (P = .003), Mayo Elbow Performance Score (P = .011), and visual analog scale (P = .032). Interestingly, patients in the Q4 group had the poorest clinical outcomes. However, no significant differences were found among the 4 groups in new onset or exacerbation of nerve symptoms (P = .919), reduced muscle strength (P = .536), instability (P = .567), or infection (P = .374) at the last follow-up.

CONCLUSION

This study confirms that in patients with post-traumatic elbow stiffness, abnormal serum uric acid metabolism was a risk factor for poor performance and postoperative pain after arthrolysis. Therefore, detecting the preoperative serum uric acid levels of the patients would be helpful for evaluating the postoperative outcomes.

Serum uric acid concentration is not associated with handgrip strength, lean body mass or survival in gastrointestinal cancer patients

BACKGROUND AND AIMS

Serum uric acid (UA) concentrations are associated with physical capacity and muscle strength. In cancer patients, this relationship may influence the prognosis and survival. However, studies are controversial and require further research. Thus, this study aimed to evaluate if there is an association between the serum UA concentrations with handgrip strength (HGS), lean body mass (LBM) and survival probability in gastrointestinal tract cancer patients.

METHODS

A retrospective cross-sectional study enrolled patients of both genders and over 18 years old. All data was collected from medical records after an initial consultation with a dietitian. UA concentrations were dichotomized using the sample mean values, high ≥4.17 mg/dL and low <4.17 mg/dL.

RESULTS

From the 101 patients, 46 were women and 55 men. Those with high UA also included individuals with a history of smoking (p = 0.004), greater HGS (p = 0.008), greater LBM (p = 0.026) and a greater total caloric intake (p = 0.028). In the logistic regression analysis, no association was found between UA and HGS (OR: 1.03 95% CI: 0.96-1.10, p = 0.337) and LBM (OR: 1.03 95% CI: 0.96-1.11, p = 0.301) after adjusting for gender, whether or not the patient smokes, and total caloric intake. Further, survival probability did not change among the high and low UA concentrations.

CONCLUSION

In gastrointestinal tract cancer patients, serum UA concentrations were not linked to muscle strength, lean mass nor survival.

High serum uric acid level is associated with greater handgrip strength in the aged population

BACKGROUND

We aimed to investigate the association of serum UA level with muscle strength assessed by handgrip strength (HGS) in a large Korean adult population.

METHODS

Cross-sectional data were obtained from the seventh Korea National Health and Nutrition Examination Survey (KNHANES) 2016. The KNHANES 2016 study included 8150 subjects, of whom 4230 subjects were analyzed in this study. The association between serum UA level and HGS was investigated with adjustment for confounding factors.

RESULTS

Serum UA was divided into sex-specific tertiles After adjustment for potential confounding factors, HGS was significantly greater in the high serum UA group (the third tertile) than in the low UA group (the first tertile) in the elderly (age ≥ 60 years) population (coefficient β [95% confidence interval (CI)] = 1.017 [0.115-1.920]). When the elderly population was subdivided according to the presence of metabolic syndrome (metS), the impact of UA remained significant only in individuals with metS. In the aged population, high serum UA level reduced the risk for low HGS (OR, 95% CI = 0.69, 0.48-0.98, p = 0.041) only in male subjects.

CONCLUSIONS

A population-based cross-sectional survey in Korea revealed that high serum UA level is associated with increased HGS in the aged population. The antioxidant property of UA may enhance muscle strength, especially in the elderly population.