Table 1.
General characteristics of studies included in the present systematic review and meta-analysis of prospective studies on the association of dietary sodium intake with all-cause and cardiovascular mortality
| Study | Country | Age (years), range or mean | Mean Na intake (mg/d) | Sex | Sample size | No. of all-cause deaths | No. of CVD deaths | Duration follow-up (years) | Exposure assessment | Na intake categories | Outcome | OR or RR | 95 % CI | Adjustments* | Study quality |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Saulnier et al. (2017)( 38 ) | France | 65·3 | 2047 | F/M | 1439 | 429 | 254 | 5·7 | 24 h urinary Na excretion | –† | All-cause/CVD mortality | All-cause: 0·73 CVD: 0·66 | 0·63, 0·85 0·54, 0·81 | 1, 2, 3, 4, 5 | 7 |
| Cook et al. (2016)( 26 ) | USA | 44·6 | 4046 | F/M | 3011 | 272 | – | 10 | 24 h urinary Na excretion | <2300, 2300–3600, 3600–4800, ≥4800 mg/d | All-cause mortality | All-cause: 1·42 | 1·22, 1·66 | 1, 2, 3, 6, 7, 8, 9, 10, 11, 12, 13 | 5 |
| Singer et al. (2015)( 33 ) | USA | 52 | 2990 | F/M | 3505 | 3052 | 1120 | 20 | 24 h urinary Na excretion | Q1, Q2, Q3, Q4‡ | All-cause/CVD mortality | All-cause: 1·23 CVD: 1·00 | 1·00, 1·51 0·70, 1·41 | 1, 2, 3, 14, 15, 16, 17, 18, 19, 20, 21, 22 | 9 |
| Kalogeropoulos et al. (2015)( 31 ) | USA | 73·6 | 2550 | F/M | 2642 | 881 | – | 10 | Dietary intake (FFQ) | <1500, 1500–2300, >2300 mg/d | All-cause mortality | All-cause: 1·02 | 0·95, 1·11 | 1, 2, 4, 9, 14, 15, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34 | 7 |
| Horikawa et al. (2014)( 29 ) | Japan | 58·7 | 4250 | F/M | 1588 | 75 | – | 8 | Dietary intake (FFQ) | Q1, Q2, Q3, Q4‡ | All-cause mortality | All-cause: 0·81 | 0·38, 1·73 | 1, 2, 8, 9, 15, 16, 24, 35, 36, 37, 38, 39, 40, 41, 42, 43 | 5 |
| Ikehara et al. (2012)( 30 ) | Japan | 57·2 | 1994 | F/M | 35 515 | – | 4417 | 16·4 | Dietary intake (FFQ) | Low, moderate, high | CVD mortality | CVD: 1·05 | 0·96, 1·15 | 1, 6, 8, 9, 15, 23, 27, 44, 45, 46,47 | 5 |
| Gardener et al. (2012)( 44 ) | USA | 69 | ~3314 | F/M | 2657 | – | 371 | 10 | Dietary intake (FFQ) | ≤1500, 1501–2300, 2301–3999, 4000–10 000 mg/d | CVD mortality | CVD: 1·49 | 0·81, 2·72 | 1, 2, 6, 8, 9, 11, 15, 23, 24, 27, 42, 48, 49, 50, 51, 52, 53 | 8 |
| Costa et al. (2012)( 43 ) | Brazil | 58·7 | 1855 | F/M | 372 | – | 61 | 1·02 | Dietary intake (FFQ) | –† | CVD mortality | CVD: 2·76 | 1·18, 6·47 | 1, 2, 54, 55, 56, 57 | 6 |
| Yang et al. (2011)( 34 ) | USA | 25–74 | 3594 | F/M | 12 267 | 2270 | NR | 14·8 | Dietary intake (24 h recall) | Q1, Q2, Q3, Q4‡ | All-cause/CVD mortality | All-cause: 1·73 CVD: 0·83 | 1·54, 2·63 0·31, 2·28 | 2, 6, 8, 9, 11, 12, 15, 24, 34, 38, 42 | 5 |
| O’Donnell et al. (2011)( 32 ) | Canada | 66·5 | 4770 | F/M | 28880 | 3430 | 2057 | 4·67 | 24 h urinary Na excretion | <2, 2–2·99, 3–3·99, 4–5·99, 6–6·99, 7–8, >8 g/d | All-cause/CVD mortality | All-cause: 1·31 CVD: 1·21 | 1·30, 1·31 1·20, 1·21 | 1, 2, 3, 4, 7, 11, 15, 58, 59, 60, 61, 62 | 6 |
| Stolarz-Skrzypek et al. (2011)( 40 ) | Belgium | 39·7 | 4094 | F/M | 3681 | 219 | 84 | 7·9 | 24 h urinary Na excretion | Low, moderate, high | All-cause/CVD mortality | All-cause: 0·92 CVD: 0·60 | 0·88, 0·96 0·58, 0·60 | 1, 2, 3, 6, 8, 9, 15, 16, 27, 34, 43, 63 | 7 |
| Ekinci et al. (2011)( 42 ) | Australia | 64 | 4232 | F/M | 638 | 175 | 75 | 9·9 | 24 h urinary Na excretion | –† | All-cause/CVD mortality | All-cause: 0·72 CVD: 0·65 | 0·55, 0·94 0·44, 0·95 | – | 4 |
| Dong et al. (2010)( 37 ) | China | 59·4 | 1897 | F/M | 305 | 74 | 32 | 2·62 | Dietary intake (3 d food record) | –† | All-cause/CVD mortality | All-cause: 0·44 CVD: 0·11 | 0·20, 0·95 0·03, 0·48 | 2, 4, 15, 25, 27, 33, 37, 64, 65, 66, 67, 68 | 5 |
| Cohen et al. (2008)( 11 ) | USA | 48 | 3231 | F/M | 8699 | 1150 | 436 | 8·7 | Dietary intake (24 h recall) | Q1=<2060, Q2=2060–2921, Q3=2922–4·047, Q4=4048–9946 mg/d‡ | All-cause/CVD mortality | All-cause: 0·80 CVD: 0·55 | 0·59, 1·10 0·32, 0·95 | 1, 2, 6, 7, 8, 9, 10, 14, 16, 27, 34, 42, 43, 69, 70, 71 | 5 |
| Umesawa et al. (2008)( 25 ) | Japan | 56·2 | 2103 | F/M | 58 730 | – | 2087 | 12·7 | Dietary intake (FFQ) | Q1, Q2, Q3, Q4, Q5§ | CVD mortality | CVD: 1·42 | 1·20, 1·69 | 1, 2, 6, 8, 9, 15, 23, 27, 44, 45, 46, 67, 71, 72, 73 | 6 |
| Geleijnse et al. (2007)( 27 ) | Netherlands | 69·2 | 2691 | F/M | 1448 | 420 | – | 5 | 24 h urinary Na excretion | Q1, Q2, Q3, Q4‡ | All-cause mortality | All-cause: 0·98 | 0·54, 1·78 | 1, 2, 3, 4, 6, 8, 9, 15, 27, 42, 49, 67, 74 | 5 |
| Cohen et al. (2006)( 36 ) | USA | 48 | 2718 | F/M | 7154 | 1343 | 541 | 13·7 | Dietary intake (24 h recall) | <2300, ≥2300 mg/d | All-cause/CVD mortality | All-cause: 0·83 CVD: 0·71 | 0·73, 0·94 0·57, 0·88 | 1, 2 | 5 |
| Nagata et al. (2004)( 41 ) | Japan | 54 | 5659 | M | 13 355 | – | 137 | 7 | 24 h urinary Na excretion | Low, moderate, high | CVD mortality | CVD: 2·33 | 1·23, 4·45 | 1, 6, 7, 8, 9, 15, 23, 27, 42, 48, 71, 75, 76 | 5 |
| Nagata et al. (2004)( 41 ) | Japan | 55·2 | 5210 | F | 15 724 | – | 132 | 7 | 24 h urinary Na excretion | Low, moderate, high | CVD mortality | CVD: 1·7 | 0·96, 3·02 | 1, 6, 7, 8, 9, 15, 23, 27, 42, 48, 71, 75, 76 | 5 |
| Tuomilehto et al. (2001)( 39 ) | Finland | 45·5 | 4140 | F/M | 2436 | 180 | 87 | NR | 24 h urinary Na excretion | –† | All-cause/CVD mortality | All-cause: 1·22 CVD: 1·36 | 1·02, 1·47 1·05, 1·76 | 1, 2, 9, 15, 16, 34, 38, 77 | 8 |
| He et al. (1999)( 28 ) | USA | 48·2 | 1952 | F/M | 6797 | 1676 | 566 | 19 | Dietary intake (24 h recall) | Q1, Q2, Q3, Q4‡ | All-cause/CVD mortality | All-cause: 1·02 CVD: 1·18 | 0·88, 1·19 0·92, 1·51 | 1, 2, 6, 8, 9, 14, 15, 16, 24, 27, 34, 42, 74 | 5 |
| Alderman et al. (1998)( 35 ) | USA | 49·2 | 2023 | F/M | 11 346 | 3923 | 1970 | 20 | Dietary intake (24 h recall) | –† | All-cause/CVD mortality | All-cause: 0·88 CVD: 0·89 | 0·80, 0·96 0·77, 1·02 | NR | 3 |
F, female; M, male; NR, not reported.
Adjustments: 1, age; 2, sex; 3, urinary potassium; 4, creatinine; 5, estimated 24 h Na excretion; 6, education; 7, exercise; 8, alcohol use; 9, current smoking; 10, weight; 11, race/ethnicity; 12, family history of CVD; 13, clinic and treatment assignment; 14, race; 15, BMI; 16, systolic blood pressure; 17, estimated glomerular filtration rate, 18, haematocrit; 19, plasma renin activity; 20, history of diabetes mellitus; 21, history of smoking; 22, history of baseline left ventricular hypertrophy; 23, history of hypertension; 24, physical activity; 25, prevalent CVD; 26, pulmonary disease; 27, history of diabetes; 28, depression; 29, blood pressure; 30, heart rate; 31, electrocardiogram abnormalities; 32, serum glucose; 33, serum albumin; 34, cholesterol; 35, glycosylated Hb (HbA1c); 36, diabetes duration; 37, LDL-cholesterol; 38, HDL-cholesterol; 39, log-transformed TAG; 40, treatment by insulin; 41, treatment by lipid-lowering agents; 42, energy intake; 43, treatment for hypertension; 44, time spent on sports activity; 45, walking time; 46, perceived mental stress; 47, fresh fish intake; 48, protein intake; 49, saturated fat intake; 50, carbohydrate intake; 51, hypercholesterolaemia; 52, previous cardiac disease; 53, total fat intake; 54, myocardial infarction; 55, left ventricular end-diastolic volume; 56, C-reactive protein; 57, brain natriuretic peptide; 58, prior history of stroke or myocardial infarction; 59, co-morbid vascular risk factors; 60, treatment allocation; 61, fruit and vegetable consumption; 62, baseline blood pressure and change in systolic blood pressure from baseline to last follow-up; 63, study population; 64, average mean arterial pressure; 65, Hb; 66, phosphate intake; 67, calcium intake; 68, Kt/V; 69, added table salt; 70, history of cancer; 71, dietary potassium; 72, menopause; 73, hormone replacement therapy; 74, diuretic use; 75, marital status; 76, intake of vitamin E; 77, study year.
Reported risk of mortality for continuous intake of Na.
Quartiles.
Quintiles.