Hyperuricemia and gout are included among such lifestyle-related diseases as obesity, diabetes, hypertension and dyslipidemia. Hyperuricemia involves the serum urate level exceeding the solubility limit, the resulting crystallized urate deposits causing gouty arthritis and a renal disorder induced by gout. Uric acid is an end product of purine nucleotide degradation. This review summarizes recent biochemical and molecular biological data from principally Japanese studies on purine nucleotide biosynthesis, uric acid formation and its renal excretion. The Japanese Society of Gout and Nucleic Acid Metabolism published in 2001 guidelines for the management of hyperuricemia and gout in order to standardize the diagnosis and therapy of these disorders. These guidelines define hyperuricemia as a urate concentration of over 7mg/dl in the blood, indicating the solubility limit based on the physicochemical properties of urate. The required change of patients' lifestyles, including dietary habits, is also reviewed
The basal metabolic rate (BMR) in 46 fit older people (age: 66±3yrs., height: 163.3±9.5cm, body weight (BW): 59.0±10.4kg; mean±SD) was evaluated in relation to the body composition (body fat mass (FM): 15.3± 4.0kg, lean body mass (LBM): 43.7±9.5kg). BMR for all the subjects was 1, 328±218kcal/day, 22.6±1.9kcal/kgBW/day, and 30.9±3.6kcal/kgLBM/day. BMR (kcal/day) was significantly correlated with BW (r=0.87, p<0.001) and LBM (r=0.85, p<0.001). The height, BW, BMI and LBM were significantly higher in the males than in the females (p<0.01, respectively). No difference was apparent in FM between the two sexes. BMR (kcal/day) was higher in the males than in the females (p<0.01), but the males had lower BMR in terms of kcal/kgBW/day and kcal/kgLBM/day than the females (p<0.05 and p<0.01, respectively). No significant difference was apparent in the adjusted BMR (kcal/(kgLBM±24.5)/day) between the males and females. A multiple-regression analysis showed the most powerful predictor to be LBM and the second most powerful to be FM of BMR in fit older people.
The effect is investigated of dietary magnesium (Mg) supplementation on the Mg, calcium (Ca) and phosphorus (P) utilization in Mg-deficient rats. Three-week-old male Wistar rats were fed on either a control diet (control group) or Mg-deficient diet (Mg-deficient group) for 28 days. Half the rats in the Mg-deficient group were then changed from the Mg-deficient diet to the control diet (recovery group) for 14 days. The Mg-deficient group displayed a change in Mg, Ca and P utilization (balance study and serum level). After the diet had been changed, the apparent absorption of Mg, the urinary excretion of Mg and Ca, and the retention of Mg and P were significantly higher in the recovery group than in the Mg-deficient group. The urinary P excretion was also significantly lower in the recovery group than in the Mg-deficient group. The serum Mg and P levels were also significantly higher in the recovery group than in the Mg-deficient group after the diet had been changed, while the serum Ca level was significantly lower in the recovery group than in the Mg-deficient group. The results of this study suggest that the Mg-deficient diet induced changes in the Mg and P balance, and that the serum levels of Mg, Ca and P were restored by changing from the Mg-deficient diet to the control diet.