Microalbuminuria is an early predictor of clinically significant diabetic nephropathy in people with non-insulin-dependent diabetes mellitus(NIDDM) or insulin-dependent diabetes mellitus(IDDM). In addition, microalbuminuria is associated with
increased
cardiovascular mortality in NIDDM and diabetic proliferative retinopathy.
Despite of considerable research, we still do not have a comprehensive explanation for the pathogenesis of diabetic neuropathy. Although chronic hyperglycemia is almost certainly involved, it is not known whether the primary pathology is
metabolic
and
microvascular, or an interaction between the two.
The aim of the present study is to measure the peripheral nerve and autonomic nerve function in NIDDM patients in relation to degree of albuminuria, and assess the hypothesis that microalbuminuria could also be a marker of diabetic neuropathy.
One hundred fifty-five subjects, 132 NIDDM subjects who attended Diabetic Clinic of Wonkwang University Hospital and 23 nondiabetic controls, were included in this study. Patients were divided into 3 groups according to their urinary albumin
excretion,
based on three kinds of samples during an observation period of at least 6 months such as <20 ㎍/min(normoalbuminuria), ≥20 but ≤200㎍/min(microalbuminuria), and >200㎍/min (macroalbuminuria).
The Quantum model "Q84" was utilized for peripheral somatic neurologic test such as measured sural and peroneal nerve conduction velocities. Determination of autonomic nerve dysfunction was based on standardized battery of bedside
tests(AUTOCAFT).
Infrared portable pupillometry was used for measuring the pupil diameter. Urinary albumin excretion(UAE) was measured by radioimmunoassay. Hb A1c was determined by high performance liquid chromatography(HPLC). Retinopathy was assessed by
fundoscopy.
@ES The results obtained are summerized as follows:
@EN 1) In The peripheral nerve examination, significant slowing of sural and peroneal nerve conduction velocity was observed in macro and microalbuminuria group compaired to control group. These results shows that peripheral neuropathy in the
microalbuminuric group was considerably higher than that of control group.
2) In the examination of autonomic function, there was a significant decrease in respiratory sinus arrhythmia, lying and standing blood pressure respond to heart rate change. Valalva ratio. autonomic score, and pupil diameter in microalbuminuria
group
compaired to control group. And these results shows that autonomic neuropathy in the microalbuminuric group was considerably higher than that of control group.
3) There is an association between the aggravation of microalbuminuria and the advancement of somatic, and autonomic neuropathy in diabetic patients.
Our data indicated that at the microalbuminuria stage, a significant peripheral somatic and autonomic dysfunction were already present.
In conclusion, we have shown that diabetic neuropathy is associated with microalbuminuria. This association lends support to theory of a vascular etiology for the peipheral and autonomic neuropathy of diabetes mellitus, and microalbuinuria could
also be
a marker of diabetic neuropathy.
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