The positive correlation found in this study between fasting glucose levels and arginase activity, with no correlation with Arg-1 levels, may indirectly indicate a potential role of Arg-2, whose levels were not determined in this study but have been shown in the pathogenesis of diabetes complications such as diabetic nephropathy [51] and diabetic retinopathy [52]. Here, ARG2 is linked to diabetic retinopathy.