Geriatric assessment and chronic kidney disease in the oldest old: the Octabaix study.

Background: The prevalence of chronic kidney disease (CKD) in older people is increasing. We determine the proportion of CKD in a sample of 321, 85-year-old community-dwelling subjects, and assess the association of socio-demographic data, global geriatric assessment data and comorbidity with CKD according to the estimated glomerular filtration rate (eGFR) of subjects.

Methods: Serum creatinine, eGFR (derived in ml/min/1.73 m(2) using the Modification of Diet in Renal Disease formula), socio-demographic variables, the Barthel Index (BI), the Spanish version of the Mini-Mental State Examination (MEC), the Mini Nutritional Assessment (MNA), the Charlson Index, the Gait Rating Scale, social risk, quality of life and prevalent chronic diseases were collected.

Results: CKD prevalence was 56.7% for eGFR < 60 ml/min/1.73 m(2), 19.9% for eGFR < 45 ml/min/1.73 m(2) and 6.6% for GFR < 30 ml/min/1.73 m(2). Multiple logistic regression analysis showed that a prior diagnosis of hypertension was associated with an eGFR < 60 ml/min/1.73 m(2) (p<0.008, OR 2.134, 95% CI 1.216-3.744). A diagnosis of heart failure (p<0.001, OR 3.610, 95% CI 1.677-7.771) and a poor score on the quality of life measure (p<0.008, OR 0.9660, 95% CI 0.966-0.995) were associated with an eGFR < 45 ml/min/1.73 m(2).

Conclusions: More than half of the oldest old in this study had an eGFR < 60 ml/min/1.73 m(2). A history of hypertension was associated with CKD. The group of patients with an eGFR < 45 ml/min/1.73 m(2) was associated with a diagnosis of heart failure and a worse quality of life.