Table 1.
Demographic and anthropometric characteristics and serum biochemistry for uric acid stone formers and age-, sex-, and body mass index–matched nonstone formers
| Variable | N | Uric Acid Stone Formers, n=38 | N | BMI-Matched Nonstone Formers, n=38 |
|---|---|---|---|---|
| Age, yr | 53 (46–62) | 55 (48–62) | ||
| Sex (women/men) | 12/26 | 12/26 | ||
| Race/ethnicitya | ||||
| Asian | 1 | 3% | 1 | 3% |
| Black | 4 | 11% | 11 | 29% |
| Hispanic | 3 | 8% | 3 | 8% |
| White | 30 | 79% | 23 | 61% |
| BMI, kg/m2 | 32.5 (29.1–36.5) | 31.6 (27.1–35.1) | ||
| Sodium, mmol/L | 138 (137–139) | 137 (136–139) | ||
| Potassium, mmol/L | 4.2 (4.0–4.4) | 4.3 (4.1–4.5) | ||
| Chloride, mmol/L | 105 (103–107) | 104 (103–106) | ||
| Bicarbonate, mmol/L | 25 (25–28) | 26 (25–27) | ||
| pH | 7.38 (7.36–7.39) | 7.39 (7.38–7.40) | ||
| Uric acid, mg/dl | 8.1 (7.1–9.2) | 6.8 (5.4–7.6)b | ||
| BUN, mg/dl | 15 (11–19) | 12 (10–14)b | ||
| Creatinine, mg/dl | 1.00 (0.86–1.40) | 0.88 (0.76–1.01)b | ||
| Triglycerides, mg/dl | 191 (132–291) | 156 (102–179)b | ||
| Total cholesterol, mg/dl | 200 (179–230) | 191 (174–217) | ||
| LDL cholesterol, mg/dl | 119 (104–151) | 113 (97–140) | ||
| HDL cholesterol, mg/dl | 40 (32–45) | 40 (38–47) | ||
| Free fatty acids, mmol/L | 0.38 (0.33–0.56) | 0.38 (0.35–0.47) | ||
| Fasting glucose, mg/dl | 100 (89–118) | 91 (84–97)b | ||
| Type 2 diabetes | 12 | 32% | 9 | 24% |
| HOMA-IR (in nondiabetic subjects) | 1.89 (1.00–2.31) | 1.13 (0.68–1.45) |
Data are presented as median (interquartile range) or percentage. BMI, body mass index; HOMA-IR, Homeostatic Model Assessment—Insulin Resistance.
a
Percentages for race/ethnicity may not add up to 100% because of rounding.
b
P<0.05 compared with uric acid stone formers.