Alkaline phosphatase is independently associated with renal function in normoalbuminuric type 1 diabetic patients

Nonalcoholic fatty liver disease (NAFLD) is associated with an increased prevalence of chronic kidney disease in patients with type 1 diabetes. The aim of this study was to explore the relationship between markers of NAFLD, namely concentrations of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALK), γ-glutamyltransferase (GGT), bilirubin, and renal function in type 1 diabetic patients. This study included 313 normoalbuminuric type 1 diabetic patients with estimated glomerular filtration rate (eGFR) >60 mL/min/1.73 m(2), without clinical evidence of cirrhosis or other causes of chronic liver disease and before any interventions with statins, angiotensin-converting enzyme (ACE) inhibitors or angiotensin II receptor blockers. ALT, GGT, and bilirubin levels were significantly higher in subjects in the highest quartile of serum creatinine compared to those in lowest quartile (21 vs. 20 U/L, 18 vs. 14 U/L, and 14 vs. 10 µmol/L, respectively, for all p < 0.05). ALK levels were significantly higher in subjects in the highest quartile of urinary albumin excretion rate compared to those in lowest quartile (71 vs. 69 U/L, p = 0.03), as well as in hyperfiltrating subjects compared to those with normal or mildly impaired eGFR (81 vs. 68 and 64 U/L, p < 0.001). In a multiple logistic regression model adjusted for age, sex, duration of diabetes, HbA1c, and body mass index (BMI), only ALK levels were significantly associated with disturbances in serum creatinine and eGFR in our subjects (p ≤ 0.007), with odds ratios of 0.98-1.02. NAFLD associated markers, particularly ALK, are associated with renal function in normoalbuminuric type 1 diabetic patients.