The association of folate or vitamin B12 intake with physical performance in elderly people

B-PROOF subproject Cross-sectional study about the association of folate or vitamin B12 intake with physical performance in elderly people with an elevated homocysteine level

By Jalien Broersen and Daniëlle Dull Thesis number: 2011112 January 2011

Wageningen University Division of Human Nutrition

Hogeschool van Amsterdam Bacheloropleiding Voeding en Diëtetiek

Title The association of folate or vitamin B12 intake with physical performance in elderly people.

Authors Jalien Broersen Regthuisstraat 60 1724 SN Oudkarspel

Daniëlle Dull Lisweg 395 1511 XS Oostzaan

Thesis number 2011112

In order of Wageningen University Division of Human Nutrition PO Box 8129 6700 EV Wageningen

External supervisors Ir. Janneke van Wijngaarden Dr. Ir. Rosalie Dhonukshe-Rutten Karin Borgonjen

Internal supervisors Ir. Halime Ozturk Dr. Ir. Willem Gerritsen

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Words of gratitude This thesis is written as final assignment for our bachelor study Voeding & Diëtetiek at the Hogeschool van Amsterdam. From September 2010 until January 2011 we investigated the association of folate or vitamin B12 intake with physical performance in elderly people. This was an assignment of the B-PROOF study, located at the Wageningen University and Research centre, division of Human Nutrition. During our time at the B-PROOF study, we did not only write this thesis, but we were also part of the B-PROOF team. The past five months we learned a lot and gained a lot of experience. We are very thankful for having the opportunity to be a part of such a large study as the B-PROOF study. We learned a lot about writing a thesis, literature research, statistical analysis and participating in a large intervention study. At first we would like to thank our supervisor from the B-PROOF study, Janneke van Wijngaarden, for supporting us. You were always ready to help and support us, even when you were very busy. We appreciate your enthusiasm and we learned a lot from you. The feedback you gave was always very clear and you motivated us to improve our thesis every time. We could not wish a better supervisor! We want to thank Rosalie Dhonukshe-Rutten and Karin Borgonjen. Rosalie, for your clear feedback and bright ideas. Karin for supporting us with the Food Frequency Questionnaires. We also want to say thanks to our teacher Halime Ozturk of the Hogeschool van Amsterdam for all her feedback and advices during writing this thesis. Willem Gerritsen, our second teacher of the Hogeschool van Amsterdam, gave us good feedback for which we want to thank him as well. We want to thank the whole B-PROOF team for the good cooperation and the nice time in the B-PROOF room and in Wageningen. We have enjoyed working with all of you. Finally we would like to thank our friends and family, for the supporting moments when we needed that. Hopefully you will enjoy reading this thesis.

Jalien Broersen and Daniëlle Dull

Wageningen, January 2011

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Abstract Background: The percentage of elderly people (65 years and older) in the Netherlands has increased from 7.7% in 1950 to 15% in 2010. The expectation is that this percentage will be doubled to 26% in 2040. About one fifth of the elderly people have limitations in daily activities and it is important to examine how quality of life can be kept as high as possible, which might result into lowering healthcare costs. A diminished physical performance is associated with an elevated risk of mortality. Multiple studies showed that the homocysteine level is an indicator for the level of physical performance. Vitamin B12 and folate are necessary to convert homocysteine into methionine, a higher intake thus resulting in lowering the homocysteine level. Literature research had not resulted into finding studies which investigated the association of folate or vitamin B12 intake with physical performance, which makes this topic interesting. The aim of this research is to investigate the association of folate or vitamin B12 intake with physical performance in elderly people with an elevated homocysteine level in the Netherlands. Methods: In this study, 158 participants of the B-PROOF study with an age above 65 years and an elevated homocysteine level were included. Folate and vitamin B12 intake were measured with a validated 190-item Food Frequency Questionnaire. Physical performance was measured with the Short Physical Performance Battery (SPPB), consisting of walking test, chair stand test, balance test and a sum score. Multiple regression analysis was used to assess the association of the single parts of physical performance and sum score with folate intake, vitamin B12 intake or homocysteine level. Results: After adjustment for covariates, there was an association observed of folate intake with the sum score of physical performance in men (p=0.045) and homocysteine level with walking test in men (p=0.02), but not in women. No associations were observed between folate intake and the single physical tests. No associations of vitamin B12 with the sum score and the single parts of physical performance were observed. There were also no associations observed of homocysteine level with chair stand test, balance test and sum score. Conclusion: Folate intake is positively associated with physical performance, based on a sum score of the walking test, chair stand test and balance test, in men but not in women. An increase of 400 µg folate should theoretically result in an increase of 3.2 points on the SPPB score in comparison to elderly with a mean intake of folate. The homocysteine level is positively associated with walking test in men, but this is not relevant. To walk one second faster over six meters, the homocysteine level should decrease with 9 µmol. There are no associations of vitamin B12 intake with the sum score and the single parts of physical performance, of folate intake with the single parts of physical performance and homocysteine level with chair stand test, balance test and sum score. Key words: folate, vitamin B12, physical performance, Food Frequency Questionnaire, elderly.

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Abbreviations ADL B-PROOF cm EAR FFQ kcal kg L LAPAQ m µg MC ml mmHg mmol mol MMSE MNA n ng OESO p RDA s SE SNAQ SPPB VUMC WUR

= Activities of Daily Living = B-vitamins for the prevention of osteoporotic fractures = centimetre = Estimated Average Requirements = Food Frequency Questionnaire = kilocalorie = kilogram = Litre = LASA Physical Activity Questionnaire = meter = microgram = Medisch Centrum = millilitre = millimeters of mercury = millimole = micromole = Mini-Mental State Examination = Mini Nutritional Assessment = number = nanogram = Organisatie van Economische Samenwerking en Ontwikkeling = probability = Recommended Dietary Allowance = seconds = Standard Error = Short Nutritional Assessment Questionnaire = Short Physical Performance Battery = Vrije Universiteit Medisch Centrum = Wageningen University & Research centre

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Table of contents

Words of gratitude .....................................................................................................................3 Abstract ......................................................................................................................................4 Abbreviations .............................................................................................................................5 Table of contents ........................................................................................................................6 1. Introduction ............................................................................................................................7 2. Methods .................................................................................................................................9 2.1 B-PROOF ..................................................................................................................9 2.2 Study population .....................................................................................................9 2.3 FFQ...........................................................................................................................9 2.4 Short Physical Performance Battery (SPPB) ......................................................... 11 2.5 Statistical Analysis ................................................................................................ 12 3. Results ................................................................................................................................. 13 3.1 Baseline characteristics ........................................................................................ 13 3.2 Folate and vitamin B12 intake .............................................................................. 13 3.3 Association of folate intake, vitamin B12 intake and homocysteine level with physical performance ................................................................................................ 14 4. Discussion ............................................................................................................................ 17 5. Conclusion ........................................................................................................................... 20 6. References ........................................................................................................................... 21 Appendix I. Tables outcomes multiple regression analysis ..................................................... 24

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1. Introduction The percentage of elderly people (65 years and older) in The Netherlands has increased from 7.7% in 1950 to 15% in 2010 according to numbers of the Centraal Bureau voor de Statistiek. The expectation is that this percentage will be almost doubled to 26% in 2040.1,2 It is important to examine how the quality of life of elderly can be held as high as possible. Elderly have in comparison to younger people high healthcare costs. In 2005, the average healthcare costs of a person aged 25-44 was €2883 versus €29.172 for an elderly aged 85+ in the Netherlands.3 An improved quality of life might lower the healthcare costs. Eighteen percent of the elderly has a limitation in activities such as eating, drinking, sitting down and getting up from a chair and moving outdoors. These activities are part of the Activities of Daily Living (ADL). 4 Furthermore, 22% of the elderly has a limitation in agility, measured by the OESO-indicator.4 The OESO-indicator includes hearing, seeing and motion. Motion is measured by activities such as carrying an object of 5 kg during 10 meters, stooping, taking something off the ground, and a 400 meters walk without stopping.5 Several studies investigated the effect of a diminished physical performance in elderly people on mortality.6,7 Abellan van Kan et al. reported through a systematic review that there is enough evidence to state that the walking speed of community-dwelling elderly is useful to determine the risk of adverse consequences (such as cognitive impairment, disablement, institutionalization, falling and mortality).6 Also Roland et al. showed that there is an association between a diminished physical performance and an elevated risk of mortality. However it is not yet known if improvement of physical performance may actually lower the risk of mortality.7 Kuo et al. showed that the homocysteine level might be an important indicator for the level of physical performance.8 In addition to this, Kuo et al. showed that per standard deviation increase of the homocysteine level there is a 50% higher risk for being in the lowest quartile of physical performance.9,10 Samouré et al. showed that a higher homocysteine level is associated with a higher risk for being in the lowest quartile of the walking speed and balance tests.11 Among others an adequate intake of folate and vitamin B12 are necessary to maintain a normal homocysteine level (