Table 4.
Cross-sectional studies: mixed-effect meta-analysis 25OHD and hypertension stratification
| Stratification | Sample size | Risk of hypertension associated with high 25OHD | Heterogeneity (I2) |
|---|---|---|---|
| Total | 90,535 | 0.79 (0.73–0.87)* | 45.37* |
| Journal quality | |||
| High (score =6) | 23,521 | 0.79 (0.73–0.87)* | 0.00 |
| Middle (score =5) | 23,676 | 0.71 (0.61–0.83)* | 39.43 |
| Low (score =4) | 43,338 | 0.87 (0.75–1.01) | 46.13 |
| Demographic | |||
| Age | |||
| Older (≧55 years old) | 18,736 | 0.79 (0.70–0.89)* | 0.00 |
| Younger (<55 years old) | 71,799 | 0.79 (0.70–0.88)* | 63.83* |
| Gender | |||
| Both (female and male) | 42,881 | 0.81 (0.71–0.93)* | 57.76* |
| Female | 33,540 | 0.72 (0.59–0.87)* | 45.96 |
| Male | 14,114 | 0.86 (0.75–0.99)* | 6.68 |
| Country region | |||
| Asia Pacific | 10,370 | 0.78 (0.59–1.04) | 70.21* |
| Europe | 14,724 | 0.79 (0.65–0.95)* | 17.93 |
| US | 35,384 | 0.79 (0.68–0.91)* | 3.39 |
| Others | 30,057 | 0.85 (0.78–0.93)* | 44.10 |
| Ethnicity | |||
| Asian | 9,509 | 0.85 (0.65–1.12) | 66.10* |
| Caucasian | 20,604 | 0.79 (0.55–0.95)* | 42.63 |
| Multi-ethnic groups (US) | 17,810 | 0.58 (0.28–1.18) | 78.86* |
| Others | 42,612 | 0.83 (0.78–0.89)* | 0.00 |
| Vitamin D | |||
| Vitamin D level | |||
| High (≧50 nmol/L) | 76,408 | 0.78 (0.71–0.86)* | 46.98* |
| Low (<50 nmol/L) | 14,127 | 0.85 (0.70, 1.05) | 49.38 |
| High age, low 25OHD | |||
| No | 78,166 | 0.79 (0.71–0.88)* | 57.63* |
| Yes | 12,369 | 0.81 (0.70–0.94)* | 0.00 |
| Season | |||
| No season | 55,107 | 0.80 (0.71–0.91)* | 56.60* |
| Season | 35,428 | 0.77 (0.69–0.86)* | 23.45 |
| Assay method | |||
| CLIA | 9,563 | 0.84 (0.68–1.05) | 0.00 |
| ELISA | 6,293 | 0.72 (0.61–0.85)* | 0.00 |
| HPLC | 830 | 0.31 (0.09–1.09) | 0.00 |
| Nichols Advantage | 2,722 | 0.37 (0.19–0.71)* | 0.00 |
| RIA | 70,836 | 0.82 (0.78–0.87)* | 53.90* |
| Roche | 291 | 0.54 (0.31–0.95)* | 0.00 |
| Hypertension | |||
| Hypertension self-report | |||
| No | 86,586 | 0.79 (0.73–0.87)* | 45.61* |
| Yes | 3,949 | 0.78 (0.48–1.29) | 71.50* |
| Antihypertensive treatment | |||
| No | 6,785 | 0.88 (0.61–1.28) | 71.95* |
| Yes | 83,750 | 0.79 (0.73–0.85)* | 31.37 |
| Confounders | |||
| BMI | |||
| No | 37,596 | 0.81 (0.66–0.99)* | 70.32* |
| Yes | 52,939 | 0.79 (0.71–0.87)* | 39.00* |
| PA | |||
| No | 56,600 | 0.79 (0.67–0.94)* | 67.71* |
| Yes | 33,935 | 0.78 (0.72–0.84)* | 1.63 |
| Diabetes status | |||
| No | 74,462 | 0.80 (0.70–0.90)* | 55.87* |
| Yes | 16,073 | 0.79 (0.72–0.86)* | 0.00 |
Note:
*
Significance P<0.05.
Abbreviations: 25OHD, 25-hydroxyvitamin D; US, United States; CLIA, chemiluminescence immunoassay; ELISA, enzyme-linked immunosorbent assay; HPLC, high-pressure liquid chromatography; RIA, radioimmunoassay; BMI, body mass index; PA, physical activity.