Table 3.
Trials testing the effect of sodium reduction in feeding studies among people with diabetes
| Study | Design | Comparison | N | Age (yrs) | Males (%) | Race | Population | Study Dur (wks) | BP Δ in lower sodium group | BP Δ in higher sodium group | Between-group Difference in BP Δ (lower sodium-higher sodium) | Contrast in 24-hour urine sodium |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| De’Oliveira, 1997 (51) | Parallel study | Low sodium (10mmol NaCl or 228mg sodium)* vs high sodium (200mmol NaCl or 4563mg sodium)* | 19 | 56 | 84 | White 90%, African American, 10% | Type 2 diabetes | 1 | NR | NR | †MAP higher in high vs. low sodium group, between-group diff −9.0mmHg, p-value NR | UNa excretion similar in low vs. high sodium group, 14±2 mmol/day and 195±7 mmol/day respectively, between-group diff NR, NS |
| Imanishi, 2001 (46) | Crossover study | Low sodium (80mmol or 1840mg)* vs. normal sodium (200 mmol or 4600mg)*; stratified by albuminuria: normal, micro or macro | 32 | 59–62 | 59 | NR | Type 2 diabetes, inpatients, simple diabetic retinopathy, excluded those on BP meds | 1 | NR | NR | Normoalbuminuria and normotension: SBP lower in low vs. normal sodium diet; †between-group diff −7.0mmHg, p<0.001 No between-group difference in DBP Microalbuminuria and normotension: †between-group diff in SBP −11.0 mmHg, p<0.001; DBP −6.0mmHg, p=0.0021 |
NR |
| Miller, 1995 (50) | Crossover study | Low sodium (10–20mmol or 230–460mg) vs. high sodium (250mmol or 5750mg)*; control (no diabetes) vs. diabetes | 9 | 26 | 100 | NR | Type 1 diabetes, within 5 years of diagnosis, normotensive, nonobese, no microalbuminuria | 1 | NR | NR | †MAP was similar in both groups, between-group diff −1.0mmHg, p-value NR | UNa excretion higher in high vs. low sodium group, 247±22 mmol/day and 15±2 mmol/day respectively, between-group diff NR, p≤0.05 |
| Miller, 1997 (49) | Crossover study | Low sodium (20mmol or 460mg)* vs. high sodium (200mmol or 4600mg)*; control (no diabetes) vs. diabetes | 12 | 23 | 100 | NR | Type 1 diabetes, within 5 years of diagnosis, normotensive, no proteinuria | 1 | NR | NR | †MAP was similar in both groups, between-group diff −1.0mmHg, p-value NR | UNa excretion higher in high vs. low sodium group, 201±10 mmol/day and 19±2mmol/day respectively, between-group diff NR, p≤0.05 |
| Trevisan, 1998 (48) | Crossover study | Low sodium (25mmol sodium chloride or 570mg sodium)* vs. high sodium (250mmol sodium chloride or 5700mg sodium)*; normal vs. micro-albuminuria | 16 | 38–42 | 75 | NR | Type 1 diabetes, BMI<27kg/m2; with microalbuminuria and untreated HTN vs. control without HTN and normal albumin excretion | 1 | NR | NR | With microalbuminuria: †Between-group diff in MAP −9.0mmHg, p<0.001 Without microalbuminuria: †Between-group diff in MAP 3.0mmHg, NS |
UNa excretion higher in high vs. low sodium diet within groups (p<0.0001) but not between groups |
| Vedovato, 2004 (45) | Crossover study | Low (25mmol sodium chloride or 570mg sodium)* vs. High (250mmol sodium chloride or 5700mg sodium)*; control (diabetes w/o micro- albuminuria) vs. diabetes w/ micro-albuminuria | 41 | 57–60 | 76 | NR | Type 2 diabetes, with and without microalbuminuria, normotensive | 1 | No change | NR | With microalbuminuria: †Between-group diff in MAP −8.0mmHg p<0.0001 Without microalbuminuria: †Between-group diff in MAP, −1.0 mmHg, NS |
No between-group difference in mean UNa excretion for those with or without microalbuminuria |
| Yoshioka, 1998 (47) | Crossover study | Low sodium (85mEq or 1960mg)* vs. high sodium (225mEq or 5192 mg)*; Stratified by albuminuria: normal vs micro vs. advanced albuminuria | 19 | 60 | 58 | NR | Type 2 diabetes, excluded those on prior or current BP treatment or elevated BP >160/95 mmHg | 1 | NR | NR | MAP similar between low and high salt diet when stratified by albuminuria status Microalbuminuria: †Between-group diff 3.0mmHg, p-value NR Normoalbuminuria: †Between-group diff 2.0mmHg, p-value NR |
UNa excretion higher in high vs. low sodium diet among 3 groups stratified by albuminuria status, p<0.01 |
Abbreviations: DBP, diastolic blood pressure; MAP, mean arterial pressure; NR, not reported; NS, non-significant; SBP, systolic blood pressure; UNa, urine sodium
*
Sodium content converted from mmol or mEq of sodium or sodium chloride to mg of sodium based on guidance from CDC: https://www.cdc.gov/salt/sodium_toolkit.htm
†
Calculated between-group difference