The association between urinary and dietary potassium and diabetic microvascular complications: insights from UK...

Potassium plays an important role in glucose metabolism and blood vessel. However, there is a lack of systematic research on the intake of potassium and diabetic microvascular complications. The aim of this study was to explore whether inadequate potassium intake increases the risk of developing diabetic microvascular complications, diabetic nephropathy, diabetic retinopathy, and diabetic neuropathy using the UK Biobank database.

This study included 22,395 subjects with type 2 diabetes mellitus at baseline. Urinary potassium and creatinine were measured by potentiometry and photometric assay respectively. Dietary potassium intake was measured using the 24-hour dietary recall method. The occurrence of microvascular complications was determined using ICD-10 codes from cumulative hospitalization records and death records in the national death registry. Cox proportional hazards models were used to explore the relationship between urinary potassium-to-creatinine ratio, dietary potassium, and overall and individual microvascular complications, generating hazard ratios (HRs) and 95% confidence intervals (CIs).

Compared with the minimum potassium-to-creatinine ratio group, the highest potassium-to-creatinine ratio group had a significantly lower risk of diabetic microvascular complications (HR, 0.70 [95% CI 0.63-0.78]; P for trend < 0.001) and diabetic nephropathy (HR, 0.54 [95% CI 0.47-0.61]; P for trend < 0.001). The group with the highest dietary potassium had a significantly lower risk of diabetic nephropathy (HR, 0.48 [95% CI 0.29-0.80], P for trend = 0.005) than the minimum dietary potassium group. The restricted cubic spline results showed a non-linear relationship between urinary potassium-to-creatinine ratio and overall microvascular complications and diabetic nephropathy, with nonlinear P values of 0.009 and < 0.001, respectively, and a generally declining trend.

The urinary potassium-to-creatinine ratio was significantly negatively associated with overall diabetic microvascular complications and diabetic nephropathy.