Vitamin D Status and Health-care Outcomes in an Ambulatory Population of Patients with Diabetes and Chronic Kidney disease: A Five-year Follow-up.

Abstract

Vitamin D (VitD) deficiency is a prevalent condition in Canada, especially in northern latitudes where sunlight exposure is limited. Elderly patients especially those with chronic conditions such as Diabetes Mellitus (DM) and Chronic Kidney Disease (CKD) have a higher risk of developing vitD deficiency. Elderly patients with CKD also have a higher risk of developing other conditions like decreased bone health, decreased health related quality of life (HRQoL), depression and frailty. The exact relationship between vitD status and the development of these other conditions is still not clear, but associations have been reported in the literature. Two studies will be described. The first is a cross sectional study (n=41) on the relationship between vitD and frailty and the second study examines the longitudinal associations of vitamin D with HRQoL, mental health, cognitive status and body composition (n=50) in an ambulatory adult population with DM and CKD over five years. The findings of these studies indicate that these patients have a high rate of vitD supplementation (1000-2000 IU/D of vitD3) with the majority of participants having sufficient vitD status defined as 25(OH)D levels above 75 nmol/l. Participants with frailty (predominantly pre-frail) had an increased number of health events, increased depression and decreased HRQoL. While most participants had lower HRQoL than Canadian norms, participants with frailty were markedly lower than those without frailty. Over five years, body composition (total or segmental, lean mass or fat mass), HRQoL, cognition or mental health remained stable with no significant changes. VitD sufficiency was associated with lower major depression inventory scores (less depression) as well as increased HRQoL scores in the vitality and mental health domains. Both frailty and vitD deficiency remain public health concerns, especially in populations with DM and CKD. A better understanding of the underlying mechanisms for the development of frailty, as well as the role of vitD in these mechanisms is required.