A Brief Review of AFP's "Diabetic Nephropathy—The Family Physician’s Role"

Diabetic Nephropathy—The Family Physician’s Role
MICHELLE A. ROETT, MD, MPH; SARAH LIEGL, MD; and YALDA JABBARPOUR, MD, Georgetown University Medical Center, Washington, District of Columbia
Am Fam Physician. 2012 May 1;85(9):883-889.
http://www.aafp.org/afp/2012/0501/p883.pdf

     Diabetes is a leading cause of renal disease. Renal disease, cardiovascular events, and all-cause mortality are associate with increased microalbuminuria levels. Microalbuminuria is defined as 30-300mg of albumin in a 24-hour sample.  Risk factors for microalbuminuria include hypertension, high glucose levels, high cholesterol, and smoking. In diabetes, microalbuminuria leads to macroalbuminuria, which leads to loss of GFR, which leads to ESRD. Patients diagnosed with IDDM (type 1) should be screened within five years of diagnosis. NIDDM (type 2) patients should be screened immediately. Yearly albumin levels can be used to track disease progression. During diagnosis, microalbuminuria should be confirmed at least two more times over the next three to six months. Microalbumin is a inflammatory marker for many diseases, so seeing it elevated over a long time period is a better determining factor than a once time lab. Patients with chronic kidney injury should have an ultrasound to rule out reversible causes.
     Besides lifestyle management, ACEIs and ARBs have been shown to improve and prevent kidney disease progression, by lowering blood pressure and glycemic level. According to the ACCORD trial , the aggressive approach of lowering AIC level, although it may reduce the risk of microalbuminuria, will increase the amount of hypoglycemic events and increase all-cause mortality.  Lowering blood pressure to below 130/80 with ACEIs or ARBs is beneficial too. Studies of aggressive pressure control have had adverse outcomes including hypotension, bradycardia, lower GFR, and elevated creatinine. Combinations of ACEIs and ARBS have no additional benefit.
    The ADVANCE trial showed that perindopril and indapamide lower nephropathy, albumin, and mortality. It did not affect the rate of ESRD.
      A low protein diet will be beneficial in these patients. Supplemental folic acid, vitamin B6 and cyanocobalamin should be avoided because they can affect GFR.