There were mistakes in Tables 1–3 as published. We identified some errors in the calculation of derived ratio indices (PLP/PL, PLP/PA, PAr) reported in the manuscript. The corrected Tables 1–3 appears below.
Table 1.
Baseline characteristics by sex in the healthy population.
| Variable | Total (n = 367) | Male (n = 197) | Female (n = 170) | P value |
|---|---|---|---|---|
| Age (years) | 49.0 (33.0, 60.0) | 49.0 (32.0, 60.0) | 48.0 (35.0, 61.0) | 0.617 |
| Height (cm) | 167.2 (162.0, 174.8) | 174.0 (170.0, 178.3) | 161.8 (157.5, 165.2) | < 0.001 |
| Weight (kg) | 63.3 (55.6, 72.0) | 70.3 (64.2, 76.2) | 56.0 (51.2, 60.8) | < 0.001 |
| BMI (kg/m2) | 22.5 (20.6, 24.5) | 23.5 (21.7, 25.4) | 21.6 (19.7, 23.5) | < 0.001 |
| SBP (mmHg) | 123.0 (111.0, 136.0) | 126.0 (116.0, 136.0) | 117.0 (106.0, 134.0) | 0.001 |
| DBP (mmHg) | 75.0 (69.0, 83.0) | 78.0 (72.0, 85.0) | 72.0 (65.0, 78.0) | < 0.001 |
| Cholesterol (mmol/L) | 4.9 (4.4, 5.5) | 4.8 (4.2, 5.3) | 5.0 (4.6, 5.7) | < 0.001 |
| Triglyceride (mmol/L) | 1.1 (0.8, 1.6) | 1.1 (0.8, 1.6) | 1.0 (0.8, 1.6) | 0.034 |
| CRP (mg/L) | 0.5 (0.2, 0.9) | 0.5 (0.2, 1.0) | 0.5 (0.2, 0.9) | 0.745 |
| HGB (g/L) | 144.5 ± 14.8 | 154.4 ± 10.6 | 132.8 ± 9.5 | < 0.001 |
| Albumin (g/L) | 45.9 ± 2.4 | 46.3 ± 2.5 | 45.3 ± 2.3 | < 0.001 |
| ALT (U/L) | 18.0 (13.0, 25.0) | 20.0 (15.0, 28.0) | 15.5 (12.0, 21.2) | < 0.001 |
| HbA1c (%) | 5.50 (5.20, 5.80) | 5.50 (5.20, 5.80) | 5.40 (5.20, 5.70) | 0.542 |
| eGFR (mL/min/1.732) | 94.7 (85.0, 104.4) | 92.9 (85.0, 101.0) | 97.6 (85.8, 107.0) | < 0.001 |
| Uric acid (μmol/L) | 341.0 (285.5, 396.5) | 387.0 (336.5, 426.0) | 291.5 (252.8, 338.2) | < 0.001 |
| Calcium (mmol/L) | 2.37 (2.30, 2.43) | 2.4 (2.3, 2.4) | 2.37 (2.32, 2.43) | 0.489 |
| Phosphorus (mmol/L) | 1.08 ± 0.14 | 1.03 ± 0.14 | 1.14 ± 0.11 | < 0.001 |
| ALP (U/L) | 69.0 (59.0, 82.0) | 71.0 (63.0, 82.0) | 66.0 (55.8, 82.0) | 0.006 |
| PLP (nmol/L) | 35.48 (26.07, 49.24) | 32.47 (24.86, 46.11) | 39.24 (28.65, 50.36) | 0.004 |
| PL (nmol/L) | 14.91 (11.63, 18.05) | 14.12 (11.15, 16.73) | 15.67 (12.49, 18.96) | 0.003 |
| PA (nmol/L) | 15.79 (12.81, 20.26) | 16.18 (13.16, 19.80) | 15.29 (12.50, 20.81) | 0.959 |
| PLP/PL | 2.42 (2.01, 2.87) | 2.37 (1.97, 2.89) | 2.51 (2.10, 2.84) | 0.216 |
| PLP/PA | 2.18 (1.67, 3.05) | 1.99 (1.61, 2.87) | 2.37 (1.75, 3.23) | 0.003 |
| PAr | 0.32 (0.24, 0.41) | 0.34 (0.25, 0.43) | 0.30 (0.23, 0.39) | 0.003 |
Normally distributed variables were compared using independent t-tests and reported as mean ± standard deviation, while non-normally distributed variables were analyzed with Mann–Whitney U-tests and summarized as median (Q1, Q3). Categorical variables were presented as frequency (percentage) and analyzed using Pearson's chi-square. Statistical significance was defined as two-tailed P < 0.05, with significant results bold. PAr = PA/(PLP + PL). Normal reference ranges for indices: Cholesterol: 2.80–5.90 mmol/L; Triglyceride: 0.45–1.81 mmol/L; CRP: 0–5 mg/L; HGB: 115–150 g/L; Albumin: 35.0–55.0 g/L; ALT: 0–65 U/L; HbA1c: 4.3%−6.5%; eGFR ≥ 60 mL/min/1.732; Uric acid: 210–430 μmol/L; serum calcium: 2.08–2.60 mmol/L; serum phosphorus: 0.80–1.60 mmol/L; ALP: 45–125 U/L (male), 35–100 U/L (female).
BMI, body mass index; SBP, systolic blood pressure; DBP, diastolic blood pressure; CRP, C-reactive protein; HGB, hemoglobin; ALT, alanine aminotransferase; HbA1c, glycated hemoglobin; ALP, alkaline phosphatase; PLP, pyridoxal 5′-phosphate; PL, pyridoxal; PA, 4-pyridoxic acid.
Table 3.
Reference intervals of vitamin B6 metabolites stratified by age and sex.
| Variable | Age group | Sex | n | Median (Q1, Q3) | P2.5 (95% CI) | P97.5 (95% CI) |
|---|---|---|---|---|---|---|
| PLP (nmol/L) | < 50 years | Male | 103 | 38.44 (26.22, 50.54) | 10.36 (7.49–16.91) | 145.87 (84.12–150.60) |
| Female | 87 | 39.65 (27.43, 56.85) | 13.03 (7.08–17.03) | 103.46 (71.05–115.04) | ||
| ≥50 years | Male | 94 | 31.68 (23.91, 40.54) | 9.27 (8.21–14.16) | 142.96 (79.11–166.95) | |
| Female | 83 | 41.38 (31.08, 50.17) | 16.83 (15.58–20.11) | 173.06 (122.80–189.85) | ||
| PL (nmol/L) | < 50 years | Male | 103 | 14.66 (11.25, 17.65) | 7.18 (6.10–8.61) | 49.95 (26.74–66.34) |
| Female | 87 | 14.78 (11.61, 17.95) | 7.48 (7.12–9.33) | 37.87 (24.65–52.11) | ||
| ≥50 years | Male | 94 | 14.00 (11.01, 16.27) | 6.58 (5.08–8.14) | 54.62 (30.87–65.87) | |
| Female | 83 | 16.99 (14.24, 19.92) | 7.78 (6.34–9.99) | 71.43 (37.75–72.74) | ||
| PA (nmol/L) | < 50 years | Male | 103 | 15.67 (12.94, 18.07) | 8.19 (6.39–10.21) | 47.66 (32.32–67.21) |
| Female | 87 | 15.23 (11.68, 18.84) | 8.03 (5.84–8.68) | 35.60 (27.52–44.61) | ||
| ≥50 years | Male | 94 | 17.25 (13.76, 21.35) | 9.23 (7.53–10.26) | 46.35 (31.34–66.11) | |
| Female | 83 | 18.45 (14.14, 22.87) | 9.34 (7.32–11.25) | 52.90 (34.72–54.43) | ||
| PLP/PL | < 50 years | Male | 103 | 2.57 (1.99, 3.17) | 1.16 (0.93–1.48) | 4.23 (3.88–4.66) |
| Female | 87 | 2.55 (2.18, 2.88) | 1.47 (0.97–1.77) | 4.06 (3.42–4.18) | ||
| ≥50 years | Male | 94 | 2.28 (1.90, 2.68) | 1.27 (1.17–1.39) | 3.34 (3.18–4.09) | |
| Female | 83 | 2.41 (1.96, 2.78) | 1.39 (1.35–1.59) | 3.56 (3.37–3.60) | ||
| PLP/PA | < 50 years | Male | 103 | 2.42 (1.68, 3.12) | 0.76 (0.59–1.14) | 5.15 (4.35–5.45) |
| Female | 87 | 2.60 (1.74, 3.33) | 1.27 (0.88–1.41) | 5.73 (4.51–7.62) | ||
| ≥50 years | Male | 94 | 1.96 (1.38, 2.49) | 0.57 (0.43–1.00) | 3.99 (3.46–6.12) | |
| Female | 83 | 2.41 (1.72, 3.13) | 1.08 (0.95–1.37) | 4.76 (3.79–5.73) | ||
| PAr | < 50 years | Male | 103 | 0.32 (0.24, 0.40) | 0.15 (0.15–0.18) | 0.69 (0.58–0.86) |
| Female | 87 | 0.30 (0.22, 0.37) | 0.14 (0.10–0.17) | 0.54 (0.48–0.56) | ||
| ≥50 years | Male | 94 | 0.38 (0.28, 0.47) | 0.19 (0.13–0.21) | 1.03 (0.66–1.37) | |
| Female | 83 | 0.32 (0.24, 0.39) | 0.16 (0.13–0.19) | 0.57 (0.47–0.61) |
The robust method based on Horn's algorithm was used to calculate 95% reference intervals (P2.5–P97.5), and their stability was validated via nonparametric bootstrap resampling.
PLP, pyridoxal 5′-phosphate; PL, pyridoxal; PA, 4-pyridoxic acid.
Table 2.
Sex-stratified comparisons of vitamin B6 biomarkers between participants aged < 50 and ≥50 years.
| Variable | Males | Females | ||||
|---|---|---|---|---|---|---|
| < 50 years | ≥50 years | P value | < 50 years | ≥50 years | P value | |
| PLP (nmol/L) | 38.44 (26.22, 50.54) | 31.68 (23.91, 40.54) | 0.039 | 39.65 (27.43, 56.85) | 41.38 (31.08, 50.17) | 0.185 |
| PL (nmol/L) | 14.66 (11.25, 17.65) | 14.00 (11.01, 16.27) | 0.457 | 14.78 (11.61, 17.95) | 16.99 (14.24, 19.92) | 0.002 |
| PA (nmol/L) | 15.67 (12.94, 18.07) | 17.25 (13.76, 21.35) | 0.080 | 15.23 (11.68, 18.84) | 18.45 (14.14, 22.87) | 0.001 |
| PLP/PL | 2.59 ± 0.76 | 2.29 ± 0.56 | 0.002 | 2.57 ± 0.57 | 2.42 ± 0.56 | 0.097 |
| PLP/PA | 2.33 (1.69, 3.11) | 1.91 (1.40, 2.47) | 0.001 | 2.45 (1.79, 3.30) | 2.30 (1.74, 3.11) | 0.271 |
| PAr | 0.31 (0.24, 0.40) | 0.37 (0.29, 0.46) | 0.002 | 0.30 (0.22, 0.37) | 0.31 (0.24, 0.39) | 0.373 |
Statistical significance was defined as two-tailed P < 0.05, with significant results bold. PAr = PA/(PLP + PL).
PLP, pyridoxal 5′-phosphate; PL, pyridoxal; PA, 4-pyridoxic acid.
File Supplementary Figure 1 was erroneously published with the original version of this paper. The file has now been replaced.
The original version of this article has been updated.
Footnotes
Edited and reviewed by: Yanhui Ma, Shanghai Jiao Tong University, China
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