Fatigue and vitamin D status in frail elderly with and without cancer, and healthy controls of different ages – results from the IMAGE study

Vitamin D deficiency has previously been shown to be associated with cancer-related fatigue. If vitamin D affects fatigue in frail elderly has not been studied before. The aim of this study was to investigate associations between vitamin D, fatigue, frailty and sarcopenia in frail elderly with and without cancer in comparison with healthy controls. Baseline data from the IMAGE study ('IMmunity and AGE') was used. IMAGE is an observational, prospective study originally designed to study immunity in frail elderly. In this study, data on self-assessed fatigue (0-10), vitamin D, and muscle-strength at baseline were used. Four groups were included: 1) healthy elderly ≥65 years old (HE) with a score of 1-3 on Clinical Frailty Scale (CFS); 2) frail elderly ≥65 years old (CFS 4--9) without cancer (FE); 3) with advanced cancer (FEC) and 4) healthy controls 18-64 years old (HY). 273 participants were included. HE had significantly higher vitamin D levels compared to FE and FEC, median 82 nmol/L compared to 54 and 47 nmol/L (p<0.001 for both). FE and FEC were more fatigued, median 5 (IQR 4-8) and 7 (IQR 5-8), compared to HE, median 2 (IQR 0-4) (p<0.001 for both). Regression models showed that low vitamin D were associated with increased fatigue (p<0.001), frailty (p<0.001), and reduced muscle-strength (p<0.05). Fatigue was common in frail elderly, with or without cancer, and was associated with low vitamin D. Vitamin D deficiency was associated with increasing frailty and reduced muscle-strength.