Table 1. Characteristics of studies included in the meta-analysis.
| First author (ref), year, Country | No. of cases/cohort (controls), age, follow-up | Cholesterol categories(Dietary assessment) | Risk estimates (95% CI) | Matched/adjusted factors |
|---|---|---|---|---|
| Prospective study | ||||
| Merritt et al [17], 2015, Europe | 1303/301,107 (25–70y), 11y | Quartile 1 Quartile 2 Quartile 3 Quartile 4 (Validated FFQ) |
1.00 (Ref) 0.97 (0.82–1.16) 1.00 (0.83–1.20) 1.00 (0.83–1.20) Hazard ratio |
BMI, total energy intake, smoking status, age at menarche, OC use, parity, and a combined variable for menopausal status and postmenopausal hormone use and were stratified by age and study center |
| Case-control study | ||||
| Biel et al [14], 2011, Canada, PC-CS | 506/981 (mean, 58.7/58.3y) | Quartile 1 Quartile 2 Quartile 3 Quartile 4 (Validated FFQ) |
1.00 (Ref) 1.22 (0.87–1.72) 1.29 (0.92–1.82) 1.51 (1.08–2.11) Odds Ratio |
Age, total energy intake, age at menarche, BMI, parity, educational level, hypertension history, OC use, hormone therapy use combined with menopausal status, and alcohol consumption |
| Yeh et al [18], 2009, USA, HC-CS | 541/541 (mean, 63.3/63.2y) | Quartile 1 Quartile 2 Quartile 3 Quartile 4 (FFQ) |
1.00 (Ref) 0.90 (0.61–1.31) 1.34 (0.89–2.00) 1.09 (0.65–1.85) Odds Ratio |
Age, BMI, exogenous estrogen use, smoking, total menstrual months, total energy, total protein and carbohydrates intake |
| Lucenteforte et al [15], 2008, Italy, HC-CS | 454/908 (median, 60/61y) | Quintile 1 Quintile 2 Quintile 3 Quintile 4 Quintile 5 (Validated FFQ) |
1.00 (Ref) 1.10 (0.70–1.70) 1.20 (0.80–1.80) 1.60 (1.00–2.40) 2.10 (1.40–3.20) Odds Ratio |
Age, study centre, year of interview, education, PA, BMI, history of diabetes, age at menarche, age at menopause, parity, OC use, hormone replacement therapy use, total energy intake, according to the residual models |
| Salazar-Martinez et al [19], 2005, Mexico, HC-CS | 85/629 (mean, 51.7/57.1y) | Tertile 1 Tertile 2 Tertile 3 (Validated FFQ) |
1.00 (Ref) 0.76 (0.41–1.45) 0.81 (0.37–1.76) Odds Ratio |
Age, total energy intake, number of live births, BMI, PA, and diabetes |
| Littman et al [20], 2001, USA, PC-CS | 679/944 (45–74y) | Quintile 1 Quintile 2 Quintile 3 Quintile 4 Quintile 5 (FFQ) |
1.00 (Ref) 1.10 (0.75–1.50) 1.40 (0.94–2.00) 1.30 (0.86–1.90) 1.30 (0.85–2.10) Odds Ratio |
Age, county of residence, total energy intake, unopposed estrogen use, cigarette smoking, and BMI |
| McCann et al [21], 2000, USA, PC-CS | 232/639 (mean, 63.5/55.9y) | Quartile 1 Quartile 2 Quartile 3 Quartile 4 (Validated FFQ) |
1.00 (Ref) 0.80 (0.50–1.20) 0.50 (0.30–0.90) 0.70 (0.40–1.40) Odds Ratio |
Age, education, BMI, diabetes, hypertension, pack-years cigarette smoking, age at menarche, parity, OC use, menopause status, postmenopausal estrogen use, and total energy intake |
| Tzonou et al [22],* 1996, Greece, HC-CS | 145/298 (N/A) | Quartile 1 Quartile 2 Quartile 3 Quartile 4 (FFQ) |
1.00 (Ref) 1.03 (0.58–1.82) 1.03 (0.58–1.82) 1.31 (0.75–2.29) Odds Ratio |
Age |
| Potischman et al [16], 1993, USA, PC-CS | 399/296 (mean, 59.1/58y) | Quartile 1 Quartile 2 Quartile 3 Quartile 4 (FFQ) |
1.00 (Ref) 1.50 (0.90–2.40) 0.80 (0.50–1.50) 2.00 (1.20–3.30) Odds Ratio |
Age, BMI, current smoking, years of education, number of births, ever OC use, ever menopausal estrogen use, and total calories intake |
| Barbone et al [23], 1993, USA, HC-CS | 168/334 (mean, 64/63y) | Tertile 1 Tertile 2 Tertile 3 (FFQ) |
1.00 (Ref) 1.10 (0.60–2.20) 1.60 (0.80–2.90) Odds Ratio |
Age, race, years of schooling, total calories, use of unopposed estrogens, obesity, shape of obesity, smoking, age at menarche, age at menopause, number of pregnancies, diabetes, and hypertension |
BMI, body mass index; CI, confidence interval; HC-CS, hospital-based case-control study; PA, physical activity; PC-CS, population-based case-control study; N/A, not available; OC, oral contraceptive; FFQ, food frequency questionnaire.
*
Risk estimates were calculated from published data with EpiCalc 2000 software (version 1.02; Brixton Health).