Does obesity modify the epidemiological association between hyperuricemia and the prevalence of hypertension among Northern Chinese community-dwelling people? A Chinese population-based study

Objectives Hyperuricemia and obesity both play a role in the development of hypertension. However, limited evidence is available for the combined effect of hyperuricemia and obesity on the prevalence of hypertension in the Chinese population. We aimed to assess the separate and combined effects of these two risk factors on the risk of hypertension. Methods We conducted a cross-sectional study in an area of Dalian city, Liaoning Province, China, from September 2015 to November 2016; 8700 adult residents were invited to participate in this study. Hyperuricemia was defined as serum uric acid >= 416 mu mol/L in men and >= 357 mu mol/L in women according to the guidelines. Individuals were categorised into four groups: the control group (body mass index (BMI) < 25 without hyperuricemia, the reference group), the obesity group (BMI >= 25 without hyperuricemia), the hyperuricemia group (BMI <25 with hyperuricemia) and the obese-hyperuricemia group (BMI >= 25 with hyperuricemia). A multivariable logistic model was used to investigate individual and combined effects of hyperuricemia and obesity on the risk of hypertension. Results Of the 8331 individuals included, 44.3% were obese, 13.6% suffered from hyperuricemia, and 7.8% were both obese and hyperuricemic. The hypertension prevalence was the highest in the obese-hyperuricemia group (55.5% (95% CI 51.6% to 59.2%)), followed by that in the obesity (44.3% (42.6% to 46.1%)) and that in the hyperuricemia groups (33.5% (29.5% to 37.9%)). After adjusting for confounders, the obese-hyperuricemia group had a nearly threefold increased risk of hypertension compared with their healthy counterparts (OR 2.98 (2.48 to 3.57)). This pattern was also observed in the obesity group with a higher risk of hypertension (OR 2.18 (1.96 to 2.42)) compared with the control group, whereas the risk of hypertension was not elevated significantly in the hyperuricemia group (OR 1.14 (0.92 to 1.42)). Conclusion Our study provided the first evidence that obese Chinese individuals with hyperuricemia had a significantly increased risk of hypertension compared with their healthy counterparts. This combined effect on the risk of hypertension is much stronger than the individual effect of either factor.