Table 1. Characteristics of studies included in meta-analysis.
| Study | Country | Case/Total [age(y)] | Gender M/F | Definition of Hypertension | Follow-up (years) | Comparison (Highest vs Lowest, U/L) | Adjusted RR(95%CI) | Adjustment for covariates |
| Yamada [11]; 1991 | Japan | 29/1393 (35–54) | 1393/0 | ≧160/95 | 5 | ≧50 vs <50 | 4.52(2.17–9.40) | None |
| Miura [20], 1994 | Japan | 36/77 (30–69) | 77/0 | ≧140/90, meds | 10 | ≧20 vs <10 | 5.82(1.83–18.56) | Age, SBP, DBP, alcohol consumption. |
| Per 1 SD logGGT increment | 1.41(1.09–1.83) | |||||||
| Lee [14], 2002 | Korea | 169/8170 (25–50) | 8170/0 | ≧160/95, meds | 4 | ≧50 vs ≦9 | 1.5(0.8–2.8) | Age, BMI, smoking, drinking, exercise, family history of hypertension, SBP or DBP, the change of BMI, drinking during four years. |
| Lee [13], 2003 | USA | 708/4704 (18–30) | NA | ≧140/90, meds | 15 | >36 vs ≦12 | 1.5(1.0–2.2) | Age, sex, race, study center, BMI, alcohol consumption, cigarette smoking, physical activity, systolic blood pressure, insulin. |
| Stranges [15], 2005 | USA | 195/897 (39–79) | 587/310 | ≧140/90, meds | 6 | (39–55) vs ≦14 | 2.1(1.1–4.0) | Age, gender, race, average of alcohol, smoking status, BMI, physical activity, systolic blood pressure. |
| Ander [10], 2007 | France | 492/2273 (NA) | 1129/1144 | ≧130/85, meds | 3 | M: ≧49.4 vs <19.7; F: ≧23 vs <12.6 | M:1.76(1.06–2.92); F:1.38(0.87–2.20) | Age |
| Jo [9], 2009 | Korea | 2170/17281 (NA) | 11659/5622 | ≧130/85, meds | 4 | M:>38 vs <19; F:>15 vs <9 | M:2.44(2.07–2.88); F:1.49(1.14–1.94) | Age |
| Jimba [18], 2009 | Japan | 288/1027 (49±8) | NA | ≧130/85, meds | 3 | ≧42 vs ≦24 | 1.15(0.76–1.73) | Age, sex, alcohol habit, BMI |
| Hwang [19], 2010 | Korea | 83/293 (54.1±8.9) | 115/176 | ≧140/90, meds | 5 | M: >46 vs <17; F: >19 vs <9 | M:0.5(0.1–2.8); F:7.8((2.4–25.0) | Age, education, BMI, alcohol intake, cigarette smoking, exercise, salt intake, family history of hypertension, ALT |
| Cheung [16], 2011 | China | 126/708 (47.3±9.7) | 428/280 | ≧140/90, meds | 5.3 | M: ≧31 vs ≦20; F: ≧20 vs ≦13 | 2.68(1.36–5.26) | Age, sex, systolic blood pressure at baseline, follow-up duration, BMI, triglycerides, HDL cholesterol, HOMA-IR, CRP, fibrinogen, current smoking, change in BMI |
| Per 1 SD logGGT increment | 1.38(1.05–1.81) | |||||||
| Xu [8], 2011 | China | 119/285 (NA) | NA | ≧130/85, meds | 3.5 | (41–68) vs <16 | 1.55(0.72–3.31) | Age, sex |
| Onat [12], 2012 | Turkey | 476/1423 (33–84) | 735/678 | ≧140/90, meds | 4 | Per 1 SD logGGT increment | 1.20(1.10–1.31) | Age, sex, menopause, BMI, alcohol usage |
| Kim [17], 2012 | Korea | 389/4783 (44±5.8) | 3246/1537 | ≧140/90, meds | 3 | (29–51) vs ≦12.9 | 2.638(1.259–5.528) | Age, sex, alcohol amount, smoking status, physical activity, BMI, baseline glucose, uric acid, HDL, LDL, TG, Hs-CRP, baseline systolic blood pressure |
Abbreviations: NA: not applicable; M, Man; F, Female; BMI, body mass index; ALT, alanine aminotransferase; HOMA-IR, homeostasis model assessment index of insulin resistance; CRP, C-reactive protein; HDL, high-density lipoprotein cholesterol; LDL, low-density lipoprotein cholesterol; TG, triglyceride.