1. Department of Medicine, National University Hospital , 119228 , Singapore
2. Division of Infectious Diseases , Department of Medicine, , 119228 , Singapore
3. National University Hospital , Department of Medicine, , 119228 , Singapore
4. Fast and Chronic Programme, Alexandra Hospital , 159964 , Singapore
5. Division of Advanced Internal Medicine , Department of Medicine, , 119228 , Singapore
6. Yong Loo Lin School of Medicine, National University of Singapore , 117597 , Singapore
7. Healthy Ageing Programme, Alexandra Hospital , 159964, Singapore
8. Department of Biochemistry , Yong Loo Lin School of Medicine, , 117596 , Singapore
9. National University of Singapore , Yong Loo Lin School of Medicine, , 117596 , Singapore