Table 3.
The associations of caffeine metabolite indices with serum phosphorus and with serum bicarbonate and with estimated glomerular filtration rate (eGFR), adjusting for glucose, gender, ethnicity, age, BMI, blood pressure, physical activity categories, lifetime smoking intensity, and excess of alcohol intake *.
| Overall (n = 1381) | HSI < 30 (n = 197) | 30 ≤ HSI < 36 (n = 393) |
36 ≤ HSI < 42 (n = 432) |
HSI ≥ 42 (n = 359) | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Paraxanthine | 1-MUA | Paraxanthine | 1-MUA | Paraxanthine | 1-MUA | Paraxanthine | 1-MUA | Paraxanthine | 1-MUA | |
| β (p-Value) |
β (p-Value) |
β (p-Value) |
β (p-Value) |
β (p-Value) |
β (p-Value) |
β (p-Value) |
β (p-Value) |
β (p-Value) |
β (p-Value) |
|
| Phosphorus, mmol/L | ||||||||||
| Quartile 1 (0.55–1.10) |
Ref | Ref | Ref | Ref | Ref | Ref | Ref | Ref | Ref | Ref |
| Quartile 2 (1.13–1.20) |
−0.01 (0.94) | −0.02 (0.69) | 0.07 (0.80) | −0.09 (0.65) | 0.01 (0.96) | −0.02 (0.90) | −0.19 (0.26) | −0.15 (0.25) | 0.13 (0.58) | 0.11 (0.47) |
| Quartile 3 (1.22–1.36) |
−0.04 (0.58) | 0.03 (0.61) | −0.19 (0.51) | 0.07 (0.69) | 0.04 (0.75) | −0.01 (0.94) | −0.03 (0.87) | 0.08 (0.46) | −0.11 (0.48) | 0.07 (0.54) |
| Quartile 4 (1.38–2.62) |
0.13 (0.15) | 0.11 (0.22) | 0.05 (0.90) | 0.01 (0.96) | 0.29 (0.10) | 0.25 (0.04) | 0.05 (0.82) | 0.11 (0.51) | 0.14 (0.43) | 0.03 (0.87) |
| Bicarbonate, mmol/L | ||||||||||
| Quartile 1 (15–24) |
Ref | Ref | Ref | Ref | Ref | Ref | Ref | Ref | Ref | Ref |
| Quartile 2 (25–25) |
0.15 (0.21) | 0.01 (0.88) | 0.29 (0.24) | 0.06 (0.72) | 0.03 (0.92) | −0.05 (0.74) | 0.24 (0.20) | 0.20 (0.14) | 0.13 (0.58) | −0.12 (0.43) |
| Quartile 3 (26–26) |
0.12 (0.24) | 0.12 (0.10) | 0.33 (0.25) | 0.12 (0.65) | 0.16 (0.31) | 0.15 (0.20) | −0.01 (0.96) | 0.08 (0.59) | 0.19 (0.36) | 0.17 (0.24) |
| Quartile 4 (27–38) |
0.16 (0.06) | 0.13 (0.12) | 0.47 (0.19) | 0.12 (0.67) | 0.19 (0.28) | 0.23 (0.19) | 0.04 (0.82) | 0.14 (0.33) | 0.37 (0.09) | 0.15 (0.34) |
| eGFR | ||||||||||
| >90 | Ref | Ref | Ref | Ref | Ref | Ref | Ref | Ref | Ref | Ref |
| 60 to 90 | −0.23 (0.0031) | −0.11 (0.08) | −0.64 (0.06) | −0.52 (0.03) | −0.36 (0.10) | −0.16 (0.24) | −0.34 (0.04) | −0.19 (0.28) | 0.14 (0.32) | 0.04 (0.78) |
| <60 | −0.39 (0.0010) | 0.25 (0.02) | −1.38 (0.04) | −0.62 (0.21) | −0.61 (0.03) | 0.15 (0.49) | −0.79 (0.0018) | 0.27 (0.14) | 0.68 (0.11) | 0.52 (0.23) |
* Caffeine metabolites indices were the ratios of caffeine metabolites to caffeine intake, including creatine adjusted paraxanthine/caffeine intake and creatinine adjusted 1-methyluric acid/caffeine intake; indices were log transformed. List of abbreviations: 1-MUA: 1-methyluric acid. Bolded p for trend values indicate significance using a significance level of 0.05.