Influence of sex on hyperfiltration in patients with uncomplicated type 1 diabetes

The aim of this analysis was to examine sex-based differences in renal segmental resistances in healthy controls (HCs) and patients with type 1 diabetes (T1D). We hypothesized that hyperfiltration-an early hemodynamic abnormality associated with diabetic nephropathy-would disproportionately affect women with T1D, thereby attenuating protection against the development of renal complications. Glomerular hemodynamic parameters were evaluated in HC (n = 30) and in normotensive, normoalbuminuric patients with T1D and either baseline normo-filtration [ n = 36, T1D-N, glomerular filtration rate (GFR) 90 - 134 ml.min(-1).1.73m(2)] or hyperfiltration (n = 32, T1D-H, GFR >= 135 ml.min(-1).1.73m(2)) during euglycemic conditions (4 - 6 mmol/l). Gomez's equations were used to derive efferent (RE) and afferent (RA) arteriolar resistances, glomerular hydrostatic pressure (P-GLO) from inulin (GFR) and paraaminohippurate [effective renal plasma flow (ERPF)] clearances, plasma protein and estimated ultrafiltration coefficients (K-FG). Female patients with T1D with hyperfiltration (T1D-H) had higher RE (1,985 +/- 487 vs. 1,381 +/- 296 dyne.sec(-1).cm(-5), P < 0.001) and filtration fraction (FF, 0.20 +/- 0.047 vs. 0.16 +/- 0.03 P < 0.05) and lower ERPF (876 +/- 245 vs. 1,111 +/- 298 134 ml.min(-1).1.73 m(2) P < 0.05) compared with male T1D-H patients. Overall, T1D-H patients had higher PGLO and lower RA vs. HC subjects, although there were no sex-based differences. In conclusion, female T1D-H patients had higher RE and FF and lower ERPF than their male counterparts with no associated sex differences in RA. Prospective intervention studies should consider sex as a modifier of renal hemodynamic responses to renal protective therapies.