Vitamin D analogue therapy, cardiovascular risk and kidney function in people with Type 1 diabetes mellitus and diabetic nephropathy: a randomized trial

AimTo evaluate the effects of therapy with the vitamin D analogue paricalcitol on markers of cardiovascular risk and kidney function in people with Type 1 diabetes mellitus and diabetic nephropathy. MethodsIn a double-blind, randomized placebo-controlled, crossover trial, 48 participants on stable renin angiotensin aldosterone system blockade and diuretics were assigned, in random order, to 12weeks of paricalcitol and 12weeks of placebo therapy, separated by a 4-week washout period. Primary and secondary endpoints were changes in plasma N-terminal probrain natriuretic peptide and urinary albumin excretion rate obtained before and after each intervention. Glomerular filtration rates were estimated and measured (Cr-51-EDTA plasma clearance glomerular filtration rate) after each intervention. ResultsThe mean (sd) age of the participants was 57 (9) years, the baseline geometric mean (95% CI) urinary albumin excretion rate was 148 (85-259) mg/24h, the mean (sd) HbA(1c) was 70 (9) mmol/mol [8.6 (3)%], the mean (sd) estimated glomerular filtration rate was 47 (15) ml/min/1.73m(2) and the mean (sd) 24-h blood pressure was 135 (17)/74 (10) mmHg. Compared with placebo therapy, vitamin D analogue therapy had no significant effect on plasma N-terminal probrain natriuretic peptide concentration (P=0.6), urinary albumin excretion rate was reduced by 18% (P=0.03 for comparison), estimated glomerular filtration rate was reduced by 5ml/min/1.73m(2) (P<0.001) and measured glomerular filtration rate was reduced by 1.5ml/min/1.73m(2) (P=0.2). ConclusionsParicalcitol therapy did not affect plasma N-terminal probrain natriuretic peptide concentration in people with Type 1 diabetes and diabetic nephropathy; however, the urinary albumin excretion rate was significantly lowered. What's new?