scholarly journals Age- and sex-dependent reference intervals for uric acid estimated by the truncated minimum chi-square (TMC) approach, a new indirect method

2020 ◽  
Vol 44 (3) ◽  
pp. 157-163
Author(s):  
Rainer Haeckel ◽  
Werner Wosniok ◽  
Antje Torge ◽  
Ralf Junker

Abstract Background Although the concentration of uric acid in serum or plasma is known to depend on sex and age and is subject to diurnal variation, the influence of these covariates on the reference interval (RI) is often neglected. Consequently, the values in the literature vary considerably. Therefore, we reinvestigated the reference limits and their dependence on covariates. Methods A new indirect approach was applied which derives a continuous function between age and RIs avoiding the usual “jumps” between various age groups. Results It is confirmed that the uric acid concentration in women is lower than in men. The RIs increase with age, in women more than in men. Between 80 and 90 years of age, the upper RI limit (RL) approximately reaches the same level in both sexes. Because the uric acid concentration may indicate renal insufficiency, the concentrations of creatinine and cystatin C were also measured. Both measurands showed the same behaviour as uric acid. Therefore, the age and sex dependency should be considered if the uric acid concentration is used as an indicator for hyperuricaemia (e.g. caused by gout or other metabolic diseases). Furthermore, a diurnal variation was observed. Conclusions Due to the variations of various covariates (age, sex, daytime, analytical systems), it is recommended that each laboratory should estimate its own RIs.

2021 ◽  
Vol 9 ◽  
Author(s):  
Chengjun Dai ◽  
Chaoban Wang ◽  
Fangqin Xia ◽  
Zishuo Liu ◽  
Yiqi Mo ◽  
...  

Context: Hyperuricemia is defined when the plasma uric acid concentration is above 416 μmol/L (7 mg/dl) in male adults, or 357 μmol/L (6 mg/dl) in female adults. However, there are no explicit criteria yet for children.Objective: It is necessary to set up reference intervals for the uric acid level in different age groups among children.Materials and Methods: A total of 5,439 individuals (3,258 males, 2,181 females) were included in the final statistical analysis. Reference values of all age groups were determined by statistical descriptions. Multiple linear regression analysis was applied to determine the relationship between uric acid level, BMI, and age.Results: The level of uric acid increased with age. Gender differences in uric acid level occurred after the onset of puberty. Additionally, linear regression revealed a positive correlation between the uric acid level and BMI.Discussion and Conclusion: The reference range of the uric acid level in children is inconsistent with the previous viewpoint. Body mass index plays an important role in uric acid metabolism.


2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Alina Concepción Alvarez ◽  
Ivette Camayd Viera ◽  
Lisy Vento Buigues ◽  
Yanet Fernández Martínez ◽  
Eraida Hernández ◽  
...  

AbstractObjectivesHomocysteine (Hcy) is a nonessential amino acid, produced by the demethylation of methionine. High Hcy levels, or hyperhomocysteinemia, have been associated with genetic and multifactorial diseases. Hcy reference values may vary between different populations, as Hcy levels are affected by factors such as sex, age, diet, smoking, and coffee consumption. The estimation reference interval (RI) allows to establish the normal values of this marker in population. At present, these levels are unknown in Cuba. The aim of this work is to estimate the Hcy reference intervals in Cuban children and adults.MethodsTotal Hcy concentration was quantified by high performance liquid chromatography (HPLC) in plasma. Hcy levels were evaluated in samples from 507 healthy individuals (260 children, 247 adults).ResultsRIs were estimated by nonparametric methods. We found significant differences between both age groups, but we did not find significant differences between sexes, within these groups. The established ranges were 2.56–14.55 µM and 3.63–17.19 µM for children and adults, respectively. Also, we observed a weak association between Hcy levels and age in both sex groups.ConclusionsThis is the first study that assesses Hcy reference values in Cuban population. Our results will allow the introduction of Hcy as a biochemical marker in laboratory testing.


2006 ◽  
Vol 34 (01) ◽  
pp. 77-85 ◽  
Author(s):  
Guang-Liang Chen ◽  
Wei Wei ◽  
Shu-Yun Xu

In this study, we investigated the effects and mechanisms of Total Saponin of Dioscorea (TSD) on animal experimental hyperuricemia. Mouse and rat hyperuricemic models were made by orally administering yeast extract paste once a day (30 and 20 g/kg, respectively), for 7 days. Yeast would disturb normal purine metabolism by increasing xanthine oxidase (XOD) activity and generating large quantities of uric acid. This model is similar to human hyperuricemia, which is induced by high-protein diets, due to a purine and nucleic acid metabolic disturbance. Another mouse hyperuricemia model was generated by intraperitoneal injection once with uric acid 250 mg/kg or potassium oxonate 300 mg/kg. Potassium oxonate, a urate oxidase inhibitor, can raise the serum uric acid level by inhibiting the decomposition of uric acid. Likewise, injecting uric acid can also increase serum uric acid concentration. The concentration of uric acid in serum or urine was detected by the phosphotungstic acid method, and the activity of XOD was assayed by a test kit. The results showed that TSD (240, 120 and 60 mg/kg, ig) could significantly lower the level of serum uric acid in hyperuricemic mice. TSD (120 and 60 mg/kg, ig) could also lower the level of serum uric acid in hyperuricemic rats, reduce the activity of XOD in the serum and liver of hyperuricemic rats, and increase the level of urine uric acid concentration as well as 24-hour total uric acid excretion. In conclusion, TSD possesses a potent anti-hyperuricemic effect on hyperuricemic animals, and the mechanism may be relevant in accelerating the excretion and decreasing the production of uric acid.


The Lancet ◽  
2008 ◽  
Vol 372 (9654) ◽  
pp. 1953-1961 ◽  
Author(s):  
Abbas Dehghan ◽  
Anna Köttgen ◽  
Qiong Yang ◽  
Shih-Jen Hwang ◽  
WH Linda Kao ◽  
...  

2011 ◽  
Vol 4 (2) ◽  
pp. 198 ◽  
Author(s):  
Sara Hashemi Shahraki ◽  
Abbass Eslami Rasekh

Slang usage in modern age Iran is a popular phenomenon among most male and female teenagers. How pervasive this variation of language use is among various age and sex groups in Iran has been a question of debate given the significance of religion in a theological system of social structure. The work presented in this study aims to investigate the effect of age and sex on variability of slang usage. Sixty Iranian participants were selected, and then were divided into three age groups (i.e. primary school, high school, and senior university students) each group consisting of ten males and ten females. A self-made questionnaire in the form of Discourse Completion Test (DCT) describing nine situations of friendly conversations was given to the participants. They were asked to make their choice on the responses, which ranged from formal to very informal style (common teenage slang expressions), or to write down what they wish to say under each circumstance. The results of the chi–square tests indicated that slang usage among high school students is more frequent as compared with other age groups. Unlike the popular belief suggesting that slang is used by boys rather than girls, the findings suggested that young Iranians both male and female use slang as a badge of identity showing their attachment to the social group they wish to be identified with.


2017 ◽  
Vol 473 ◽  
pp. 160-165 ◽  
Author(s):  
Cai-Feng Yue ◽  
Pin-Ning Feng ◽  
Zhen-Rong Yao ◽  
Xue-Gao Yu ◽  
Wen-bin Lin ◽  
...  

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