[Various biochemical parameters of renal tubular function in patients with type I diabetes in the third trimester of pregnancy].

The studied group comprised 47 women in the 3rd trimester of pregnancy (29-40 weeks), including 17 with type I diabetes (study group) and 30 healthy women (control group). In the study group in one case diabetes was diagnosed during pregnancy and treated with diet only, in the remaining 16 pregnant women the mean diabetes duration was 6.2 years and the mean daily insulin dose was 70 u. According to White's classification one patient was in class A, 10 in class B and 6 in class C. In all cases renal function was normal, with normal blood values of creatinine, urea, electrolytes, uric acid, protein and acid-base equilibrium. Endogenous creatinine clearance was also normal. The studied biochemical parameters of renal tubular function included: 1) deamination of amino acids--with measurement of ammonium ion (NH4+) excretion with urine, 2) carbonic acid metabolism--with determination of urinary excretion of hydrogen ions (H+), 3) urinary excretion of sodium (Na+) and potassium (K+) ions. Besides that 24-hour urine was always measured. The studied women were similarly hydrated (standard diet, fluid balance control). The results were subjected to statistical analysis. In women with type I diabetes the volume of 24-hour urine was increased, although it fell within the normal range, urinary excretion of Na+ and K+ was raised. No change was found in amino-acid deamination an carbonic acid metabolism since the excretion of NH4+ and H+ was normal.