Abstract 473: Weight Loss Improved Hyperuricemia, and Cardiac and Renal Functions in Obese Individuals

Background: Hyperuricemia (hyperUA) is a cardiovascular risk and UA levels might predict future hypertension. In this study, we evaluated the effects of chronic weight loss (WL) on UA levels, renal and cardiac functions. Methods: Obese, mild hypertensive men (n=154) on no medications were measured BMI, total body fat-mass, blood pressures (BP), UA, serum creatinine (Crn), creatinine clearance (CCr), plasma norepinephrine (NE), glucose, insulin (INS), HOMA-IR and ECG before and every 6 month after 2 yrs with WL regimens achieved with mild calorie restriction and exercise. Significant WL was defined as ≥10% WL of entry BMI at 2 yrs. LVH determined by ECG was used as an index or cardiac function parameter. Results: Significant WL (≥10%) were observed 47.8% at 1 yr and 61.8% at 2 yrs, and hyperUA were 64.3% at baseline, 43.3% at 1 yr, and 29.9% at 2 yrs. UA levels, LVH parameters, plasma NE, BMI, fat-mass, and BP levels at entry were greater and CCr was smaller in the non-WL group (<10%) at 2 yrs compared to the WL group, whereas HOMA at entry and changes in HOMA-IR over 2 yrs were similar between WL and non-WL groups. UA, Crn, NE, HOMA, BMI, fat-mass, BP significantly decreased with WL in all subjects, but the decreases in those parameters were greater in the WL group compared to non-WL group. All parameters except CCr at entry were greater in subjects with hyper UA at 2 yrs than those with normal UA at 2 yrs. Changes in NE, HOMA, Crn, CCr, and LVH parameters over 2 yrs in subjects with normal UA at 2 yrs were greater than those with hyper UA at 2 yrs. Changes in UA over 2 yrs significantly correlated with changes in NE, BMI, systolic BP, and fasting glucose (all, P<0.05). UA levels at entry correlated with changes in BMI, changes in CCr and changes in LVH parameters (all, P<0.05). Conclusions: These results demonstrate that chronic WL over 2 yrs is effective to decrease UA levels in obese subjects. Reducing UA levels by WL might link to improving glucose metabolisms, renal function (observed in CCr) and cardiac function (measured by LVH parameters). UA levels could predict the effects of WL on renal and cardiac functions. Suppression of sympathetic nervous activation by WL, but not insulin resistance, might be related to UA reduction associated with WL.