Diabetic Kidney Disease

India is the country with most of the people having diabetes, with a current figure of 50.8 million (data from International diabetic federation). Diabetes mellitus accounts for 31% of total kidney failure patients in India. Of these patients, around 60 to 70 % of them are in their earlier stages, were in another 30% in the terminal stage of renal failure, who usually come for treatment (what physicians see is the tip of the Iceberg). Kidney function measured in terms of GFR (glomerular filtration rate) normally is 125 ml/min. Symptoms of kidney failure usually manifest only when GFR falls by less than 10 ml/min. Those patients in the initial phase of kidney failure, if identified earlier and treated properly, can be prevented from progression to severe kidney disease.

Who are all prone to develop Diabetic kidney disease?

The risk of development of kidney failure is 30 to 40 percent in diabetic patients. If a relative (especially first degree) of a diabetic patient affected by kidney failure, the risk of developing kidney failure in this patient is 83 %. Urine excretion of protein (precursor of kidney failure) is very much increased in children of diabetic patients with kidney failure. Other risk factors include children born to diabetic mother and low birth weight children when they grow up. Dietary factors include intake of foods rich in added sugars.

The usual progression of Diabetic kidney disease:

Diabetic kidney disease usually starts with protein loss in urine, initially with a smaller amount (microalbuminuria), later with a larger amount of protein loss (macroalbuminuria), further leading to a gradual decrease in kidney function culminating in an increase in renal parameters like urea and creatinine. These processes usually take about 15 to 20 years from the time of onset of diabetes mellitus. Recent studies have shown that there are about 30% of people who progress to renal failure without having the phase of protein leak in urine.

Precipitating factors for progression of Diabetic kidney disease:

  • Hypertension is an important risk factor in the progression of diabetic kidney disease. Usually, blood pressure decreases during the night in a normal person, which doesn‘t happen in diabetic kidney disease patients and usually the first marker of disease progression.
  • Diabetic patients with persistent protein loss in urine are at greatly increased risk for progression of overt Kidney failure. Severe protein loss occurs after 10 years of onset of diabetes.

Who are all to be screened for the presence of kidney disease, in a diabetic person?

  • Persons with diabetes developing swelling of legs.
  • Patients having frequent urination at night, especially with a well-controlled blood sugar levels.
  • A gradual decrease in urine output.
  • Passing frothy urine, red colored urine.
  • The family history of kidney disease.
  • Those who have burning or pins and needle sensation in the foot.
  • Patients who have a diminution of vision and advised to undergo laser therapy.

High Blood Pressure and Diabetic Kidney Disease

Factors that can prevent progression of Diabetic kidney disease:

  • Achieve and maintain healthy body weight.
  • Avoiding high protein intake, normally protein rich foods will be more acidic, most them will be handled by the kidneys. In kidney failure, this acid will accumulate and precipitate progression of kidney failure. Especially animal protein must be restricted to prevent the progression, which not only provides more acid to the body but also produces more uric acid, which is a product of metabolism, causing hypertension and renal failure.
  • Decreasing table salt (sodium chloride) intake, as increased sodium content, leads to hypertension and perpetuating progression of kidney disease. As normal excretion of sodium occurs by kidneys, decreasing kidney function causes sodium to accumulate causing swelling of legs and face, later causing shortness of breath.
  • Avoid smoking/tobacco use.
  • Avoid unscrupulous use of analgesics, especially over the counter drugs and consumption of heavy metals as part of other modalities of treatment which can precipitate, or cause progression of renal failure.

Medicines that prevent progression of Diabetic kidney disease:

Medicines that are available which not only decrease blood pressures but also reducing pressures within the kidneys (intraglomerular hypertension) have been found to retard the progression of diabetic kidney disease. When these medicines are started early, further progression of kidney disease and worsening of renal parameters (urea, creatinine) can be halted, so the progression to dialysis can be prevented or at least prolonged.

Primary prevention of Diabetic kidney disease:

Adequate blood sugar control, blood pressure control may help in preventing diabetic kidney disease. Early screening for kidney disease may help in the institution of specific medications that may help in preventing further worsening of the disease.