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CHRONIC KIDNEY DISEASE CAUSES
Causes of
Chronic Kidney Disease
Diabetes
This is now the commonest
cause of end-stage kidney failure in the United States (40 per
cent of new patients) but is still behind that for
glomerulonephritis in the United Kingdom and Australia (21 per
cent).
The diagnosis of diabetic
nephropathy is usually assumed because of proteinuria, usually
with retinopathy, in patients with a history of diabetes for 10
or more years. About half of the patients have type 2 diabetes.
By 40 years from the onset
of diabetes, some 30 to 40 per cent of patients with type 1
diabetes have developed nephropathy and some, but not all.
Between 5 and 10 per cent of type 2 diabetics already have
nephropathy at the time their diabetes is diagnosed, and by 20
years from diagnosis 25 per cent of these will have overt
nephropathy.
It is not possible to
predict with certainty which diabetics will develop nephropathy,
but it is more likely in Blacks, Asians, and males, and in those
with a family history of hypertension.
There is now persuasive
evidence that good glycaemic control reduces the risk of
diabetic nephropathy, and that improving control will reduce the
risk of progression of patients with microalbuminuria to overt
nephropathy. Once overt nephropathy (proteinuria above 0.5
g/day) develops, the median time to end-stage kidney failure is
about 7 years for those with type 1 diabetes but it is more
variable in type 2.
Young people with type 1
diabetes present the greatest challenges, they often have many
additional complications such as blindness from retinopathy and
vitreous haemorrhage, peripheral and autonomic neuropathy,
precocious cardiovascular disease. The older diabetics are
usually obese and often have severe peripheral vascular and
coronary disease. Both these groups need a multidisciplinary
team to care for them, such as nephrologists, diabetologists,
ophthalmologists, vascular surgeons, and podiatrists.
Patient with nephropathy
diabetic can be exacerbated by papillary necrosis, usually
associated with pyelonephritis. They are more susceptible to
kidney tuberculosis and fungal infections, especially if
autonomic neuropathy has affected bladder function.
There is a general and
probably appropriate tendency to start dialysis earlier in those
with diabetes. In the younger patient one aims for kidney
transplantation, ideally with whole pancreas transplantation, as
early as possible. Islet-cell transplantation may, in the
future, prove to be the best option.
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