Our research is the first study on the changes in prevalence of HUA in Eastern China in recent decade. In this survey, the prevalence of HUA in the 2009 cohort and 2019 cohort were 13.3% and 18.3%, respectively. The total prevalence of HUA in the 2019 cohort was significantly higher than that in the 2009 cohort both in males and females. Liu et al.  have demonstrated that the prevalence of HUA in the Chinese population has increased rapidly from 2000 to 2014. In the United States, the prevalence of HUA has increased significantly from 18.2% in NHANES 1988–1994 to 21.4% in NHANES 2007–2008 . It was reported that the prevalence of HUA among men in the United States (21.2%) was very close to that of women (21.6%) . This is very different from our findings. We found that the prevalence of HUA among men in the Chinese population was significantly higher than that in women.
In addition, our data indicated the prevalence rates of HUA in both males and females in 2019 were significantly higher than those in 2009 (males: 26.4% vs. 17.3%; females: 7.5% vs. 4.5%). Previous studies have reported similar results in other regions of China  and in other countries such as Japan and Bangladesh [30, 31]. There was obvious gender difference in the prevalence of HUA in the 2009 and 2019 cohort, and the prevalence of HUA in men was much higher than that in women. The reason may be related to differences in estrogen levels, eating habits and weight gain between men and women. Women, influenced by traditional Chinese culture, tend to take on more housework and may also deliberately control weight to maintain their figures. Men with extensive social networks usually accept a high-fat diets or alcohol. Although the prevalence rates of HUA in females aged 20-39 years old were significantly higher in the 2019 cohort than 2009 cohort, there was no significant difference of HUA prevalence in females aged 40-79 years old between 2009 and 2019. The prevalence of HUA in females was gradually increased with age starting from the age of 40 both in 2009 and 2019.
HUA is generally considered to be a common disease in middle-aged men, and males aged 40-49 years old was indeed the main population with HUA in 2009. However, in 2019, the prevalence of HUA in young men was higher than that of middle-aged males. Among them, the prevalence of HUA in young men aged 20-29 years old in the 2019 cohort (31.92%) was nearly three times of that in males of the same age group in the 2009 cohort (10.04%). Therefore, we suggest that young men are the group with the fastest increase in the prevalence of HUA in recent 10 years. In 2019, young men have replaced middle-aged men as the main population with HUA. This condition may be due to unhealthy lifestyles in young men, including high-fat diet and lack of physical exercise, which are considered to be an important determinant of elevated serum UA levels. The high prevalence of HUA not only induces a high risk of gout , but is also associated with increased risks of hypertension, diabetes, CVD and CKD [33–35]. The rising prevalence of HUA among young men suggests that the prevalence of gout and other related metabolic disorders is also increasing. Therefore, special attention should be paid to the prevention and treatment of HUA in young males.
In our study, we also found that BMI was significantly associated with the onset of HUA both in the 2009 cohort and 2019 cohort. Obesity has become a global problem and is recognized as a risk factor leading to multiple adverse health consequences . Several studies have demonstrated the relationship between obesity and HUA [31, 36]. A positive correlation between serum UA level and obesity was found in Bangladeshi adults . A Japanese study reported that HUA was significantly associated with central obesity in obese populations rather than in normal-weight men and women . In the Chinese population, obesity was found to be a crucial risk factor for HUA in females . Therefore, our results were consistent with the previous findings. In addition, we found that BMI༞24.48kg/m2 and BMI༞23.84 kg/m2 could display good capacities to discriminate patients with HUA from non-HUA in the 2009 and 2019 cohort, respectively. This result further confirmed the association between HUA and obesity. Nevertheless, we should notice that the cut-off of BMI used to predict the onset of HUA has begun to decline in the past decade. This may imply that the people with a lower BMI than before are also likely to suffer from HUA, but the reason for this change is still unclear. It may be related to changes in diet and lifestyles to a certain extent. For example, a recent study showed that the Chinese diet was shifting to high-fat and high-energy-dense foods . The consumption of vegetable oils, animal-derived foods and processed foods that are rich in refined starch, sugar, salt and unhealthy fats continued to increase. The consumption of staple foods has gradually changed from the traditional staple foods of coarse grains to refined cereals . Moreover, according to the Global Burden of Diseases database, the burden of disease in urban areas of China, which are associated with individual behaviors and habits such as unhealthy diet, drinking, smoking and lack of physical exercise, is steadily increasing .
Our research also has several limitations. Firstly, all subjects were from a single center, which may limit the extrapolation of our conclusions. Secondly, most of the elderly who participated in this study were in good health, and patients with serious illnesses were unable to participate in our study, which may lead to an underestimation of the prevalence of HUA among the elderly. Thirdly, the drinking history, smoking history and previous medical history of these subjects were not obtained, which may also affect the results of our study.
1) The prevalence rate of HUA in Eastern China has been increasing rapidly in the past 10 years. 2) The population with the highest HUA prevalence rate in 2019 was young men aged 20-29 years, while the population with the peak prevalence rate in 2009 was middle-aged men (40-49 years old). 3) BMI was positively correlated with the occurrence of HUA, and BMI displayed a good capacity to discriminate the patients with HUA from non-HUA both in the 2009 cohort and 2019 cohort.