Development of dementia in mild cognitive impairment (MCI) patients with focus on B-vitamins

This thesis focused on the importance of low B-vitamins, hyperhomocysteinemia and the development of dementia and Alzheimer´s disease (AD) in patients with mild cognitive impairment (MCI). The relation between vitamin B12 /folate and dementia has been extensively investigated, but the results are inconsistent. The connection of thyroid stimulating hormone (TSH) and dementia is also explored in a lot of studies but neither here is a consensus found. The active fraction of vitamin B12, holo-Transcobalamin (holo-TC), is less studied. The first three studies this thesis were using data from the Geriatric Department of Karolinska University Hospital, Huddinge, Stockholm; the first study also from the Geriatric Department of Falun Hospital. In the fourth study survey data was used from the Kungsholmen Project, a longitudinal population-based study on aging and degenerative disorders in Stockholm. In paper I, we compared the serum levels of vitamin B12, folate and homocysteine in 120 persons with MCI, living either single or in a family setting. We found a higher level of serum homocysteine in men living single compared to men living in a family. In paper II, we investigated the association of homocysteine levels and the development of AD in 136 MCI patients over a three-year period. The percentage of persons who converted to AD was 31%. For the women we found that 45% with Hcy levels >16mumol/L converted to AD compared to 21% with Hcy levels 20mumol/L, 50% with Hcy levels 20-17mumol/L and none of those with levels