Table 1.
Baseline characteristics and urinary and plasma values before and after [15N, 13C5]-Hyp infusion at 0.75 µmol/h per kg
| Parameters | Controls | PH1 | PH2 | PH3 | P Value | ||||
|---|---|---|---|---|---|---|---|---|---|
| N | 9 | 7 | 4 | 8 | |||||
| Age, yr | 29.3±2.0 | 25.7±2.1 | [PH2] | 51.5±11.1 | 37±6.6 | 0.03 | |||
| Sex (M/F) | 6/3 | 4/3 | 0/4 | 8/0 | |||||
| BMI, kg/m2 | 25.2±1.2 | 24.6±1.1 | 26.2±3.3 | 28.7±2.6 | 0.45 | ||||
| GFR, ml/min per 1.73 m2 | 105±6.5 | 112.1±4.0 | 129±17.7 | 97.5±9.7 | 0.84 | ||||
| B6 treatment | 0 | 6 of 7 | 0 | 2 of 8 | |||||
| 24-h urine profile | |||||||||
| Urine oxalate, mg/g creat | 18.9±2.2 | [PH2] | 63.2±23.1 | 88.9±19.1 | 52.4±6.6 | 0.02 | |||
| Urine glycolate, mg/g creat | 36.1±9.7 | 92.4±30.8 | [PH3] | 33.0±5.1 | 16.3±5.5 | 0.03 | |||
| Urine glycerate, mg/g creat | 3.3±0.8 | 7.0±3.1 | 617.8±189.7 | [C, PH1,3] | 9.3±5.8 | <0.001 | |||
| Urine HOG, mg/g creat | <3 | <3 | <3 | 28.2±9.1 | [C, PH1] | 0.02 | |||
| Urine DHG, mg/g creat | 0.8±0.1 | 0.9±0.1 | 1.7±0.2 | 16.4±3.4 | [C, PH1,2] | <0.001 | |||
| Before infusion | |||||||||
| Plasma oxalate, μM | 2.8±0.3 | [PH1] | 6.6±1.6 | 4.3±0.4 | 4.7±0.7 | 0.02 | |||
| Plasma glycolate, μM | 4.5±0.3 | 26.9±10.2 | [C, PH3] | 7.4±1.1 | a | 3.5±0.3 | 0.01 | ||
| Plasma Hyp, μM | 10.9±0.4 | [PH1,2,3] | 6.1±0.5 | a | 8.4±0.8 | 7.5±0.7 | a | <0.001 | |
| Urine oxalate, mg/g creat | 13.2±1.5 | 72.3±24.6 | 69.5±12.2 | 43.4±6.1 | 0.07 | ||||
| Urine glycolate, mg/g creat | 23.9±5.7 | 63.4±23.1 | [PH3] | 33.0±6.8 | 9.4±2.0 | a | 0.04 | ||
| End of infusion | |||||||||
| Plasma oxalate, μM | 3.4±0.5 | 5.7±1.5 | 3.6±0.2 | 4.5±0.7 | 0.18 | ||||
| Plasma glycolate, μM | 3.9±0.3 | 25.5±9.6 | [C, PH3] | 4.4±0.5 | 3.0±0.3 | 0.01 | |||
| Plasma Hyp, μM | 10.1±0.5 | 8.3±0.6 | 9.0±1.1 | 9.5±0.4 | 0.14 | ||||
| Urine oxalate, mg/g creat | 10.4±1.4 | [PH1,3] | 65.2±20.4 | 57.0±8.8 | 49.0±4.0 | 0.004 | |||
| Urine glycolate, mg/g creat | 30.4±7.3 | 54.1±13.6 | [PH3] | 16.7±2.8 | 13.4±2.6 | 0.01 | |||
| Urine glycerate, mg/g creat | 4.6±1.3 | 2.1±0.4 | 248±84.8 | [C, PH1,3] | 1.6±0.2 | <0.001 | |||
| Urine HOG, mg/g creat | <3 | <3 | <3 | 8.5±2.5 | 0.10 | ||||
| Urine DHG, mg/g creat | 0.4±0.1 | 0.4±0.1 | 1.1±0.2 | 11.6±2.3 | [C, PH1,2] | <0.001 | |||
| Urine 13C2-oxalate, mg/g creat | 0.3±0.1 | [PH1,2,3] | 3.3±1.1 | 10.6±1.5 | [PH1,3] | 4.4±0.6 | <0.001 | ||
| Urine 13C2-glycolate, mg/g creat | 2.4±0.5 | 5.2±1.0 | [C, PH2,3] | 0.3±0.1 | 0.7±0.3 | <0.001 | |||
| Urine 13C2-HOG, mg/g creat | <0.8 | <0.8 | <0.8 | 2.3±1.0 | 0.04 | ||||
| Urine 13C2-DHG, mg/g creat | <0.2 | <0.2 | <0.2 | 0.4±0.1 | [C, PH1,2] | <0.001 | |||
| Average excretion during infusion | |||||||||
| Urine oxalate, mg/g creat | 10.6±0.6 | [PH1] | 73.1±27.9 | 70.8±18.8 | 47.0±4.0 | 0.02 | |||
| Urine glycolate, mg/g creat | 23.3±4.0 | [PH1] | 59.6±16.7 | [PH3] | 25.4±1.6 | 12.8±3.1 | 0.01 |
Each subject provided two 24-h urine collections of which the mean was used for the 24-h urine profile determinations. Urine values before the start of the infusion (also called T0, “before infusion”) and after the infusion of [15N, 13C5]-Hyp infusion (also called T360, “end of infusion”) were determined in hourly collections, started the hour before that time. The “average excretion during infusion” was calculated as the mean of all seven hourly values during the infusion and was used as total urine excretions for the calculation of contributions. Urine excretions are expressed as a ratio to creatinine excretion. Results expressed as mean±SEM, P values shown for comparisons between groups. Statistical analyses were done to compare data between groups and to compare data before and after infusion (see Methods). Significant differences between subject groups according to Tukey’s post hoc test are specified as [different from subject group] directly to the right of the means columns analyzed, [C]: different from the control group. M/F, male/female; BMI, body mass index; creat, creatinine.
Significant difference between T0 and T360 infusion time points P<0.05.