Weight Reduction and Target Serum Urate Level: A Longitudinal Study of Annual Medical Examination

Objective

Our objective was to evaluate associations of weight reduction with serum urate (SU) changes and achieving an SU level <6 mg/dL in the real-world setting, outside of specific weight reduction interventions.

Methods

We analyzed systematically collected data of annual medical examination participants from October 2012 to October 2022. Exposure was weight change (increase or decrease) between two consecutive visits, categorized as minimal (≤0.9 kg, reference), small (1.0–4.9 kg), moderate (5.0–9.9 kg), and large (≥10 kg). Outcomes included SU changes between two consecutive visits and achieving an SU level <6 mg/dL in participants with hyperuricemia (SU level ≥7 mg/dL at the previous visit).

Results

We identified 58,630 eligible participants (median age 46 years, 51.3% female, 19.4% with overweight, median SU level 5.3 mg/dL, and 5.6% with a history of gout and/or hyperuricemia) with 336,814 visits over a median of 5.3 years. After adjustment for relevant covariates, linear general estimating equations estimated mean SU changes based on observed weight reductions (vs minimal changes) were as follows: small, −0.10 mg/dL (95% confidence interval [CI] −0.10 to −0.09 mg/dL); moderate, −0.34 mg/dL (95% CI −0.36 to −0.32 mg/dL); and large, −0.64 (95% CI −0.70 to −0.58 mg/dL). In participants with hyperuricemia, adjusted relative risks for achieving an SU level <6 mg/dL by modified Poisson regression were 1.25 (95% CI 1.15–1.37) in small weight reductions, 2.82 (95% CI 2.43–3.27) in moderate weight reductions, and 5.27 (95% CI 4.15–6.70) in large weight reductions, with corresponding numbers needed to treat of 61.1 for small weight reductions, 8.5 for moderate weight reductions, and 3.6 for large weight reductions.

Conclusion

Small weight reductions were associated with only small SU changes. Some participants with hyperuricemia can achieve the target SU level with moderate to large weight reductions.