July 26th, 2020
Pre-existing diabetes mellitus
Diabetic kidney disease (DKD) is a microvascular complication of diabetes mellitus; the poorer the degree of glycemic control, the quicker the onset.
Patients with type 1 diabetes should be screened for DKD on an annual basis, starting from five years after diagnosis; patients with type 2 diabetes should also be screened annually, but from the time of diagnosis itself.
Immediate screening is recommended in the latter group, as there is often a significant time interval between the first onset of type 2 diabetes and the eventual diagnosis.
Symptoms of chronic kidney disease
Chronic kidney disease (CKD) is the end-outcome of DKD; the spectrum of associated symptoms is similar to that of CKD due to any other cause.
Symptoms of hyperglycemia
If the patient is very hyperglycemic they can suffer with polydipsia, polyuria, blurred vision and if insulin deficient, weight loss. The can also present with recurrent infections.
Symptoms of microvascular and macrovascular complications
Many of these patients have other macro- and microvascular complications of diabetes mellitus; symptoms of these conditions should be sought for.
The presence of frothy urine indicates macroalbuminuria. Albumin has a soap-like effect, reducing surface tension and thereby creating foam. Note that the presence of concomitant retinopathy is a strong sign that diabetic glomerulopathy is the underlying etiology.
Hypoglycemia may occur in patients who have developed CKD and are on insulin therapy or sulfonylureas. Suggestive symptoms include nausea, sweating, palpitations, weakness, dizziness, confusion, and altered mentation.
In the case of insulin, the underlying mechanisms include a longer circulatory half-life of insulin; a reduced capacity for renal glucose release due to the reduced kidney mass; and, a diminished counter-regulatory response to hypoglycemia due to cellular adaptation to similar episodes in the past.
In the case of sulfonylureas, the underlying mechanism is an increased circulatory half-life due to diminished renal excretion.
Presence of risk factors
Non-modifiable risk factors for DKD include a family history of the condition; Hispanic, African-American, Native American, or Pima Indian ancestry; male gender; and, advanced age.
Modifiable risk factors include poor glycemic control, poorly controlled hypertension, smoking, and obesity.