Dietary sodium and potassium intake in people with diabetes: are guidelines being met?

Despite public health bodies advocating for lowering dietary sodium and increasing potassium intake to improve cardiovascular outcomes, people with diabetes are not meeting these targets. We hypothesize that (i) both at an individual level and within the cohort, there will be a low adherence to the guidelines and (ii) sodium and potassium intake will remain stable over time.

We conducted this prospective study in a cohort of 904 participants with diabetes who provided 24-h urine collections from 2009 to 2015. Dietary sodium and potassium intake were estimated from 24-h urinary sodium (uNa) and potassium (uK) measurements. Additional data were collected for: 24-h urinary volume (uVol), creatinine (uCr),; serum creatinine, urea, estimated glomerular filtration rate (eGFR), glycated haemoglobin (HbA1c), fasting glucose, lipids); clinical characteristics (age, blood pressure (BP), body mass index (BMI) and duration of diabetes). Adherence to recommended dietary sodium (uNa < 2300 mg/24 h (100mmol/24 h)) and potassium (uK > 4680 mg/24 h(120 mmol/24)) intake were the main outcome measures.

Participants (n = 904) completed 3689 urine collections (average four collections/participant). The mean ± SD (mmol/24 h) for uNa was 181 ± 73 and uK was 76 ± 25. After correcting uNa for uCr, 7% and 5% of participants met dietary sodium and potassium guidelines respectively. Males were less likely to meet sodium guidelines (OR 0.40, p < 0.001) but were more likely to meet potassium guidelines (OR 6.13, p < 0.001). Longer duration of diabetes was associated with higher adherence to sodium and potassium guidelines (OR 1.04, p < 0.001 and OR 0.96, p = 0.006 respectively). Increasing age was significantly associated with adherence to potassium guidelines (OR 0.97, p = 0.007).

People with diabetes do not follow current dietary sodium and potassium guidelines and are less likely to change their dietary intake of sodium and potassium over time.