Hypovitaminosis D in geriatric inpatients: a marker of severity of chronic diseases.

BACKGROUND AND AIMS Hypovitaminosis D is associated with adverse health outcomes including several bone and non-bone chronic diseases. It remains unclear whether hypovitaminosis D leads to more numerous or more severe chronic diseases. Our aim was to determine whether there was an association between serum 25-hydroxyvitamin D deficiency (i.e., 25OHD ≤25 nmol/L) and, respectively, the number and severity of chronic diseases assessed with the Kaplan- Feinstein index (KFI) among geriatric inpatients. METHODS Two hundred and forty older Caucasian adults admitted between December 2008 and September 2009 to the geriatric acute care unit of Angers University Hospital, France (mean 84.6±0.4 years; 68.8% women) were included in this cross-sectional study. Serum 25OHD, KFI score and number of chronic diseases (i.e., diseases lasting at least 3 months or running a course with minimal change, whatever their nature or site) were assessed. Subjects were divided into 2 groups according to 25OHD concentration (either deficient for 25OHD ≤25 nmol/L, or non-deficient for 25OHD >25 nmol/L). Age, gender, use of vitamin D supplements, number of chronic diseases, serum parathyroid hormone and season tested were used as potential confounders. RESULTS Mean serum 25OHD concentration was 35.2 ± 1.7 nmol/L. The 102 (42.5%) subjects with 25OHD deficiency had higher KFI compared with their counterparts (p=0.008). Vitamin D deficiency was not significantly associated with the number of chronic diseases (adjusted β=-0.37 with p=0.216), but with KFI (unadjusted β=1.33 with p=0.008; adjusted β=1.37 with p=0.010). CONCLUSIONS Irrespective of the number of chronic diseases, 25OHD deficiency was associated with the severity of chronic diseases.