Lowering salt intake benefits people with diabetes

The available data from this systematic review of randomised controlled trials, assessing salt restriction, indicate that lowering sodium intake may reduce blood pressure in participants with type 1 and type 2 diabetes, with and without hypertension, and with normal or slightly abnormal kidney function.

In 7 long-term studies (treatment duration 4 to 12 weeks), the median net reduction in 24-hour urine sodium excretion was 76mmol, ranging from 51mmol to 124mmol. In 10 short-term studies (treatment duration 5 to 7 days), the median net reduction was 187mmol, with a range of 86mmol to 337mmol.

Sodium restriction may reduce systolic blood pressure by 7.36mmHg, diastolic blood pressure by 3.17mmHg and mean arterial pressure by 3.01mmHg in all participants. Only one study identified orthostatic hypotension more frequently in participants receiving a reduced sodium diet.

Lowering dietary salt intake to the recommended level of 5g per day or less would benefit people with diabetes, with or without hypertension or evidence of kidney disease, by lowering blood pressure by similar amounts as a single blood pressure medication.