Association Between Estimated GFR, Health-Related Quality of Life, and Depression Among Older Adults With Diabetes: The Diabetes and Aging Study

Background: Although chronic kidney disease (CKD) is a highly prevalent condition among older adults with diabetes, the associations between health-related quality of life (HRQoL) and severity of CKD in this population are not well understood. The objective of this study was to assess HRQoL and depressive symptoms across estimated glomerular filtration rate (eGFR) stages. Study Design: Cross-sectional. Setting & Participants: 5,805 members of Kaiser Permanente Northern California, 60 years or older with diabetes, from the 2005-2006 Diabetes Study of Northern California (DISTANCE) survey. Predictor: eGFR categories were defined as >= 90 (referent category), 75-89, 60-74, 45-59, 30-44, or <= 29 mL/min/1.73 m(2). Outcomes: HRQoL was measured using the modified Short Form -8 Physical Component Summary (PCS) and Mental Component Summary (MCS) scores. Depressive symptoms were measured using the Patient Health Questionnaire -8. Results: In unadjusted linear regression analyses, physical (PCS) and mental (MCS) HRQoL scores were significantly lower with worsening eGFR level. However, after adjustment for sociodemographics, diabetes duration, obesity, and cardiovascular comorbid conditions and taking into account interactions with proteinuria, none of the eGFR categories was significantly or substantively associated with PCS or MCS score. In both unadjusted and adjusted analyses, higher risk of depressive symptoms was observed in respondents with eGFR <= 29 mL/min/1.73 m(2) (relative risk, 2.02; 95% CI, 1.10-3.71; P < 0.05) compared with the referent group. However, this eGFR-depression relationship was no longer significant after adjusting for hemoglobin level. Limitations: Participants are part of a single health care delivery system. Conclusions: Our findings suggest the need for greater attention to and potential interventions for depression in patients with reduced eGFR. (C) 2013 by the National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.