Influence of age on gender-related differences in acute kidney injury after minimally invasive radical or partial nephrectomy.

BACKGROUND: Female gender is known to be protective against acute kidney injury (AKI) after radical or partial nephrectomy and estrogen is considered a protective factor. If estrogen is a major contributor to the protective effects of female gender against renal injury, these protective effects may be diminished in postmenopausal women. Therefore, this retrospective study investigated the influence of female age on gender-related differences in AKI after minimally invasive radical or partial nephrectomy. METHODS: Patients who underwent minimally invasive radical (n = 765) or partial (n = 1161) nephrectomy were selected. These patients were stratified by gender and divided into three age categories considered to be pre, peri, and postmenopausal periods in women: ≤ 40 years, 41-59 years, and ≥ 60 years, respectively. Adjusted logistic regression analyses were conducted to identify the risk of AKI according to gender and age. RESULTS: The incidence of AKI after radical or partial nephrectomy was significantly higher in men as compared to women in all age categories. Women aged ≥ 60 years had a significantly increased risk of AKI as compared to women aged < 60 years in radical nephrectomy, but not in partial nephrectomy. When compared with women aged ≥ 60 years, men aged > 40 years accompanied significantly higher risk of AKI following both radical and partial nephrectomy, even after adjusting confounders. However, men aged ≤ 40 years had a similar risk of AKI after radical nephrectomy, but a significantly higher risk after partial nephrectomy as compared to women aged ≥ 60 years. CONCLUSION: Male gender was associated with a higher risk of AKI after radical and partial nephrectomy as compared to postmenopausal women. This calls for more thorough preoperative counseling and renal protective strategies in male patients when undergoing radical and partial nephrectomy.