Retrospective study of factors associated with progression and remission/regression of diabetic kidney disease-hypomagnesemia was associated with progression and elevated serum alanine aminotransferase levels were associated with remission or regression.

AIM: This study was aimed at retrospectively investigating some common clinical factors, including the serum level of magnesium (Mg), associated with progression and remission/regression of diabetic kidney disease (DKD).
METHODS: The subjects were 690 Japanese patients with type 2 diabetes mellitus who were receiving treatment with oral antidiabetic drugs other than SGLT2 inhibitors. Routine clinical data were collected on the first and last day of the observation period. The prognosis of DKD is categorized into four stages according to the Kidney Disease Improving Global Outcomes classification. Progression was defined as transition from any of the lower three risk categories (LR, MIR, HR) at the start of the observation period, to the VHR stage/category at the end of the observation period. Remission/regression was defined as improvement of the risk category by at least one stage from the start to the end of the observation period. Factors associated with progression and regression/remission were investigated using Cox proportional hazards analysis. Furthermore, the factors associated with the annual decrease in eGFR of 5 ml/min/1.73 m2 or more were examined by logistic regression analysis. Factors associated with transition of urinary protein negative to trace or positive, or transition of negative or trace to positive, were investigated by Cox proportional hazard analysis.
RESULTS: The observation period was 2251 ± 1614 days. Age (Exp [B] = 1.10, 95% CI; 1.06-1.14; P < 0.01; 1 year old), serum Mg (Exp [B] = 0.82, 95% CI; 0.71-0.95; P < 0.01); 0.1 mg/dl), and serum HbA1c (Exp [B] = 1.03, 95% CI; 1.01-1.05; P < 0.01: 0.1%) were associated with progression of DKD; on the other hand, serum ALT was associated with the likelihood of remission/regression of DKD (Exp [B] = 1.01, 95% CI; 1.002-1.018; P < 0.05; 1 IU/L). The decline in eGFR was associated with higher HbA1c levels, hypomagnesemia, and lower ALT. The new appearance of trace or overt proteinuria was correlated with higher HbA1c levels, advancing age, hypomagnesemia and hypertriglycemia.
CONCLUSION: Our findings confirmed previous reports that advancing age and serum HbA1c levels were associated with an increased risk of progression of DKD. Lower serum Mg concentrations were also found to be associated with a high risk of progression of DKD, and interventional studies are needed to confirm a causal relationship. Elevated HbA1c levels and hypomagnesemia were common factors in the decline in eGFR and the appearance of trace or overt proteinuria. Lower serum ALT levels were associated with the decline in eGFR. Since serum ALT is known to decrease as the renal function deteriorates, serum ALT is considered to be a marker of renal function. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13340-020-00483-1. © The Japan Diabetes Society 2021.