CKD Progression and Mortality Among Men and Women: A Nationwide Study in Sweden

Rationale & ObjectiveChronic kidney disease (CKD) is a global health problem with increasing prevalence. Several sex-specific differences have been reported for disease progression and mortality. Selection and survival bias might have influenced the results of previous cohort studies. The objective of this study was to investigate sex-specific differences of CKD progression and mortality among patients with CKD not receiving maintenance dialysis.Study DesignObservational cohort study.Setting & ParticipantsAdult patients with incident CKD glomerular filtration rate categories 3b to 5 (G3b-G5) identified between 2010 and 2018 within the nationwide Swedish Renal Registry-CKD (SRR-CKD).ExposureSex.OutcomesTime to CKD progression (defined as a change of at least 1 CKD stage or initiation of kidney replacement therapy [KRT]) or death. Repeated assessments of estimated glomerular filtration rate (eGFR).Analytical ApproachCKD progression and mortality before KRT were assessed by the cumulative incidence function methods and Fine and Gray models, with death handled as a competing event. Sex differences in eGFR slope were estimated using mixed effects linear regression models.Results7,388 patients with incident CKD G3b, 18,282 with incident CKD G4, and 9,410 with incident CKD G5 were identified. Overall, 19.6 (95% CI, 19.2-20.0) patients per 100 patient-years progressed, and 10.1 (95% CI, 9.9-10.3) patients per 100 person-years died. Women had a lower risk of CKD progression (subhazard ratio [SHR], 0.88 [95% CI, 0.85-0.92]), and a lower all-cause (SHR, 0.90 [95% CI, 0.85-0.94]) and cardiovascular (SHR, 0.83 [95% CI, 0.76-0.90]) mortality risk. Risk factors related to a steeper decline in eGFR included age, sex, albuminuria, and type of primary kidney disease.LimitationsIncomplete data for outpatient visits and laboratory measurements and regional differences in reporting.ConclusionsCompared to women, men had a higher rate of all-cause and cardiovascular mortality, an increased risk of CKD progression, and a steeper decline in eGFR. Chronic kidney disease (CKD) is a global health problem with increasing prevalence. Several sex-specific differences have been reported for disease progression and mortality. Selection and survival bias might have influenced the results of previous cohort studies. The objective of this study was to investigate sex-specific differences of CKD progression and mortality among patients with CKD not receiving maintenance dialysis. Observational cohort study. Adult patients with incident CKD glomerular filtration rate categories 3b to 5 (G3b-G5) identified between 2010 and 2018 within the nationwide Swedish Renal Registry-CKD (SRR-CKD). Sex. Time to CKD progression (defined as a change of at least 1 CKD stage or initiation of kidney replacement therapy [KRT]) or death. Repeated assessments of estimated glomerular filtration rate (eGFR). CKD progression and mortality before KRT were assessed by the cumulative incidence function methods and Fine and Gray models, with death handled as a competing event. Sex differences in eGFR slope were estimated using mixed effects linear regression models. 7,388 patients with incident CKD G3b, 18,282 with incident CKD G4, and 9,410 with incident CKD G5 were identified. Overall, 19.6 (95% CI, 19.2-20.0) patients per 100 patient-years progressed, and 10.1 (95% CI, 9.9-10.3) patients per 100 person-years died. Women had a lower risk of CKD progression (subhazard ratio [SHR], 0.88 [95% CI, 0.85-0.92]), and a lower all-cause (SHR, 0.90 [95% CI, 0.85-0.94]) and cardiovascular (SHR, 0.83 [95% CI, 0.76-0.90]) mortality risk. Risk factors related to a steeper decline in eGFR included age, sex, albuminuria, and type of primary kidney disease. Incomplete data for outpatient visits and laboratory measurements and regional differences in reporting. Compared to women, men had a higher rate of all-cause and cardiovascular mortality, an increased risk of CKD progression, and a steeper decline in eGFR.