Aigbogun MS, Stellhorn R, Krasa H, Kostic D Severity of memory impairment in the elderly: Association with health care resource use and functional limitations in the United States. Alzheimers Dement (Amst). 2017 Apr 20;8:51-59. doi: 10.1016/j.dadm.2017.04.001. eCollection 2017.
Bajzer M, Seeley RJ Physiology: obesity and gut flora. Nature. 2006 Dec 21;444(7122):1009-10. doi: 10.1038/4441009a. No abstract available.
Browne RH On the use of a pilot sample for sample size determination. Stat Med. 1995 Sep 15;14(17):1933-40. doi: 10.1002/sim.4780141709.
Calero-Garcia MD, Navarro-Gonzalez E, Munoz-Manzano L Influence of level of activity on cognitive performance and cognitive plasticity in elderly persons. Arch Gerontol Geriatr. 2007 Nov-Dec;45(3):307-18. doi: 10.1016/j.archger.2007.01.061. Epub 2007 Mar 12.
Cani PD, Delzenne NM Gut microflora as a target for energy and metabolic homeostasis. Curr Opin Clin Nutr Metab Care. 2007 Nov;10(6):729-34. doi: 10.1097/MCO.0b013e3282efdebb.
Fama R, Sullivan EV Thalamic structures and associated cognitive functions: Relations with age and aging. Neurosci Biobehav Rev. 2015 Jul;54:29-37. doi: 10.1016/j.neubiorev.2015.03.008. Epub 2015 Apr 9.
Fernandez-Real JM, Manco M Effects of iron overload on chronic metabolic diseases. Lancet Diabetes Endocrinol. 2014 Jun;2(6):513-26. doi: 10.1016/S2213-8587(13)70174-8. Epub 2013 Dec 30.
Goodarzi MO, Bryer-Ash M Metformin revisited: re-evaluation of its properties and role in the pharmacopoeia of modern antidiabetic agents. Diabetes Obes Metab. 2005 Nov;7(6):654-65. doi: 10.1111/j.1463-1326.2004.00448.x.
Hundal RS, Inzucchi SE Metformin: new understandings, new uses. Drugs. 2003;63(18):1879-94. doi: 10.2165/00003495-200363180-00001.
Ikeda T, Iwata K, Murakami H Inhibitory effect of metformin on intestinal glucose absorption in the perfused rat intestine. Biochem Pharmacol. 2000 Apr 1;59(7):887-90. doi: 10.1016/s0006-2952(99)00396-2.
Kattenstroth JC, Kalisch T, Holt S, Tegenthoff M, Dinse HR Six months of dance intervention enhances postural, sensorimotor, and cognitive performance in elderly without affecting cardio-respiratory functions. Front Aging Neurosci. 2013 Feb 26;5:5. doi: 10.3389/fnagi.2013.00005. eCollection 2013.
Macpherson H, Teo WP, Schneider LA, Smith AE A Life-Long Approach to Physical Activity for Brain Health. Front Aging Neurosci. 2017 May 23;9:147. doi: 10.3389/fnagi.2017.00147. eCollection 2017.
Metformin in Longevity Study (MILES) - Full Text View - ClinicalTrials.gov [Internet]. [cited 2020 May 19]. Availablefrom: https://clinicaltrials.gov/ct2/show/NCT02432287
Muriach M, Flores-Bellver M, Romero FJ, Barcia JM Diabetes and the brain: oxidative stress, inflammation, and autophagy. Oxid Med Cell Longev. 2014;2014:102158. doi: 10.1155/2014/102158. Epub 2014 Aug 24.
Rea K, Dinan TG, Cryan JF The microbiome: A key regulator of stress and neuroinflammation. Neurobiol Stress. 2016 Mar 4;4:23-33. doi: 10.1016/j.ynstr.2016.03.001. eCollection 2016 Oct.
Rotella CM, Monami M, Mannucci E Metformin beyond diabetes: new life for an old drug. Curr Diabetes Rev. 2006 Aug;2(3):307-15. doi: 10.2174/157339906777950651.
Sherwin E, Dinan TG, Cryan JF Recent developments in understanding the role of the gut microbiota in brain health and disease. Ann N Y Acad Sci. 2018 May;1420(1):5-25. doi: 10.1111/nyas.13416. Epub 2017 Aug 2.
Sim J, Lewis M The size of a pilot study for a clinical trial should be calculated in relation to considerations of precision and efficiency. J Clin Epidemiol. 2012 Mar;65(3):301-8. doi: 10.1016/j.jclinepi.2011.07.011. Epub 2011 Dec 9.
Tan BL, Norhaizan ME Effect of High-Fat Diets on Oxidative Stress, Cellular Inflammatory Response and Cognitive Function. Nutrients. 2019 Oct 25;11(11):2579. doi: 10.3390/nu11112579.
Williams KN, Kemper S Interventions to reduce cognitive decline in aging. J Psychosoc Nurs Ment Health Serv. 2010 May;48(5):42-51. doi: 10.3928/02793695-20100331-03.
Interventional studies are often prospective and are specifically tailored to evaluate direct impacts of treatment or preventive measures on disease.
Observational studies are often retrospective and are used to assess potential causation in exposure-outcome relationships and therefore influence preventive methods.
Expanded access is a means by which manufacturers make investigational new drugs available, under certain circumstances, to treat a patient(s) with a serious disease or condition who cannot participate in a controlled clinical trial.
Clinical trials are conducted in a series of steps, called phases - each phase is designed to answer a separate research question.
Phase 1: Researchers test a new drug or treatment in a small group of people for the first time to evaluate its safety, determine a safe dosage range, and identify side effects.
Phase 2: The drug or treatment is given to a larger group of people to see if it is effective and to further evaluate its safety.
Phase 3: The drug or treatment is given to large groups of people to confirm its effectiveness, monitor side effects, compare it to commonly used treatments, and collect information that will allow the drug or treatment to be used safely.
Phase 4: Studies are done after the drug or treatment has been marketed to gather information on the drug's effect in various populations and any side effects associated with long-term use.