Table 3.
The relationship between dietary vitamin C consumption and Klotho concentrations, stratified by age, BMI, and sex.
| Participants | Dietary Vitamin C Consumption (mg/day) | Percent Changes (%) and 95% CI | p Value | * p for Interaction |
|---|---|---|---|---|
| Age subgroup | 0.457 | |||
| Age < 60 years | Per SD increases | 0.69 (−0.23, 1.62) | 0.147 | |
| Quintile 1 | Ref. | |||
| Quintile 2 | 2.03 (−1.15, 5.31) | 0.219 | ||
| Quintile 3 | 0.14 (−3.09, 3.49) | 0.933 | ||
| Quintile 4 | −0.10 (−3.11, 3.00) | 0.948 | ||
| Quintile 5 | 3.51 (0.10, 7.03) | 0.048 | ||
| p for trend | 0.087 | |||
| Age ≥ 60 years | Per SD increases | 1.90 (0.37, 3.43) | 0.017 | |
| Quintile 1 | Ref. | |||
| Quintile 2 | −1.53 (−5.20, 2.28) | 0.43 | ||
| Quintile 3 | 0.94 (−2.82, 4.84) | 0.63 | ||
| Quintile 4 | 0.87 (−2.68, 4.54) | 0.64 | ||
| Quintile 5 | 3.38 (−1.08, 8.05) | 0.14 | ||
| p for trend | 0.0720 | |||
| BMI subgroup | 0.009 | |||
| BMI < 25 kg/m2 | Per SD increases | 2.38 (1.17, 3.61) | <0.001 | |
| Quintile 1 | Ref. | |||
| Quintile 2 | 4.10 (−1.85, 10.22) | 0.189 | ||
| Quintile 3 | −0.93 (−6.39,4.86) | 0.749 | ||
| Quintile 4 | 4.12 (−0.81, 9.30) | 0.108 | ||
| Quintile 5 | 8.27 (2.98, 13.84) | 0.003 | ||
| p for trend | 0.002 | |||
| BMI ≥ 25 kg/m2 | Per SD increases | 0.62 (−0.38, 1.63) | 0.231 | |
| Quintile 1 | Ref. | |||
| Quintile 2 | −0.13 (−2.86, 2.69) | 0.939 | ||
| Quintile 3 | 0.98 (−1.70, 3.73) | 0.481 | ||
| Quintile 4 | −0.93 (−3.62, 1.73) | 0.490 | ||
| Quintile 5 | 2.13 (−1.05, 5.40) | 0.196 | ||
| p for trend | 0.239 | |||
| Sex subgroup | 0.146 | |||
| Male | Per SD increases | 1.80 (0.73, 2.89) | 0.002 | |
| Quintile 1 | Ref. | |||
| Quintile 2 | 1.85 (−1.31, 5.10) | 0.259 | ||
| Quintile 3 | 1.85 (−1.47, 5.28) | 0.283 | ||
| Quintile 4 | 0.34 (−2.84, 3.62) | 0.838 | ||
| Quintile 5 | 5.68 (1.97, 9.51) | 0.004 | ||
| p for trend | 0.009 | |||
| Female | Per SD increases | 0.42 (−0.73, 1.59) | 0.480 | |
| Quintile 1 | Ref. | |||
| Quintile 2 | −0.09 (−3.52, 3.47) | 0.962 | ||
| Quintile 3 | −0.83 (−3.73, 2.17) | 0.587 | ||
| Quintile 4 | 0.37 (−2.75, 3.60) | 0.817 | ||
| Quintile 5 | 1.66 (−1.82, 5.26) | 0.358 | ||
| p for trend | 0.260 |
Note: CI: confidence interval; SD: standard deviation; BMI: body mass index. The quintile of dietary vitamin C consumption ranges: Quintile 1: 0 to 17.10 mg/day; Quintile 2: 17.11 to 36.80 mg/day; Quintile 3: 36.81 to 70.60 mg/day; Quintile 4: 70.61 to 129.78 mg/day; and Quintile 5: 129.79 to 1617.80 mg/day. * p value for the interaction of vitamin C intake with age, BMI, or sex. Bold indicates significance with p < 0.05.