Decreased urinary excretion of dopamine and sodium in diabetic children with incipient nephropathy.
It has been suggested previously that a decrease in urinary dopamine output might be related to a decrease in the urinary sodium excretion in subjects with diabetic nephropathy suffering from type 2 diabetes. To investigate the renal dopamine status in children with type 1 (insulin-dependent) diabetes mellitus, we measured the 24-hour urinary excretion of dopamine, norepinephrine and sodium in 12 patients with incipient nephropathy (group A, 24-hour albumin excretion rate 70-200 micrograms/min), in 20 age matched patients with normal microalbuminuria (group B, AER less than 20 micrograms/min) and in 8 healthy controls (group C). The mean values for urinary excretion of dopamine and norepinephrine were significantly lower in group A compared to groups B and C (25.6 +/- 14.8 vs. 65.9 +/- 25.5 and 73.3 +/- 18.0 micrograms/day, p less than 0.001 and 11.8 +/- 4.6 vs. 25.1 +/- 12.1 and 28.4 +/- 8.9 micrograms/day, p less than 0.01, respectively). The mean value for the urinary excretion of sodium was also significantly lower in group A than in groups B and C (98.4 +/- 24.1 vs. 206.2 +/- 59.5 and 198.1 +/- 42.8 mEq/day, p less than 0.01). The 24-hour urinary excretion of dopamine correlated significantly with the sodium excretion (r = 0.65, p less than 0.001). Arterial blood pressure was elevated in group A compared to group C (p less than 0.01). Our results suggest that a decrease in endogenous dopamine could play a role in the low urinary sodium excretion thereby resulting in sodium retention which may in turn lead to the development of higher blood pressure in diabetic children with incipient nephropathy.
Madácsy
L
L
II. Department of Paediatrics, Postgraduate Medical University, Miskolc, Hungary.
Sulyok
E
E
Klujber
L
L
Vámosi
I
I
Barkai
L
L
Baranyai
Z
Z
D000293:Adolescent; D000419:Albuminuria / Q000175:diagnosis / Q000652:urine; D003404:Creatinine / Q000097:blood; D003922:Diabetes Mellitus, Type 1 / Q000175:diagnosis* / Q000652:urine*; D003928:Diabetic Nephropathies / Q000175:diagnosis* / Q000652:urine*; D004298:Dopamine / Q000652:urine*; D005260:Female; D006801:Humans; D006977:Hypertension, Renal / Q000175:diagnosis / Q000652:urine; D007677:Kidney Function Tests; D008297:Male; D012964:Sodium / Q000652:urine*
D012964:Sodium; D003404:Creatinine; D004298:Dopamine