Iron deficiency is the most prevalent nutritional deficiency worldwide with one in four estimated to be affected by iron deficiency anaemia. Women of reproductive age are at greatest risk for iron deficiency and anaemia due to iron losses during menstruation and childbirth as well as the increased need for iron throughout pregnancy. However, iron deficiency without anaemia is at least twice as common as iron deficiency anaemia with females aged 11-49 at the biggest risk of all. Despite this, it is commonly left undiagnosed. Those who are iron deficient non-anaemic can still suffer from the same common consequences of iron deficiency anaemia; these include unexplained fatigue, mood changes and decreased cognitive performance. Previous studies have found a significant relationship between iron status and cognitive performance in anaemic women. However, studies assessing cognition, mood and fatigue in women of varying iron status including those who are iron deficient nonanaemic are lacking. The most recent observational study of this kind found that better iron status was associated with better sustained attention but worse working memory. However, iron deficient anaemic females were not included in this observation. This study will extend upon this in order to determine any differences between non-anaemic iron deficiency and iron deficiency anaemia. The aims of this study are to improve knowledge concerning women's health and to determine whether there is a relationship between iron status, cognitive performance, subjective mood and fatigue in women of reproductive age (18-49 years).
Each participant will be required to attend the laboratory on two occasions. The first is comprised of a screening/training visit, which will take place in the afternoon for approximately 2.5 hours. This will also be between days 21-28/the week before onset of their menstrual cycle. If they do not have menstrual bleeds then this appointment can be any afternoon. This will comprise: briefing of requirements of the study; obtaining of informed consent; confirmation of eligibility to take part, including collection of demographic data and health screening, and training on the cognitive and mood measures. The training session will follow standard operating procedures to decrease the chance of learning effects during main trials. Extra training will be given where necessary. Participants will be required to complete questionnaires based upon food frequency, caffeine consumption and to estimate the number of hours of exercise completed on a weekly basis. A menstrual cycle questionnaire will also be completed to estimate menstrual blood loss and so that participants attend their testing visit during days 7-14 of their cycle. If participants do not have a menstrual cycle due to contraceptive methods, then appointments will be approximately two weeks apart. A finger-prick and venous blood sample will be collected from participants, which will be analysed for iron status. Those whose haemoglobin levels are \<120g/L will be advised to seek advice from their GP. For the testing visit, participants will be asked to fast for 12 hours prior to the visit, avoiding intake of all food and drink with the exception of water. They will also be asked to avoid alcohol and refrain from intake of 'over the counter' medication for 24 hours. Participants will arrive at the laboratory at a designated time in the morning. The following procedures will take place prior to cognitive and mood testing: * Review of continued conformity to eligibility criteria * Adverse event and concomitant medication assessment * Ensure that participant is in good health Participants will then complete the baseline cognitive and mood assessments.
Study Type
OBSERVATIONAL
Enrollment
379
Brain, Performance & Nutrition Research Centre, Northumbria University
Newcastle upon Tyne, United Kingdom
Speed of attention
An overall score for Speed of attention will be derived by calculating the average score from 3 separate standardised task outcomes (ZChoice reaction time correct reaction time + ZRapid visual information processing correct reaction time + ZDigit vigilance correct reaction time) /3
Time frame: Baseline measure
Subjective fatigue
Subjective fatigue will be derived from the total score of the Piper Fatigue Scale. Scores range from 1 to 10. Higher scores are indicative of greater fatigue.
Time frame: Baseline measure
Episodic memory
An overall score for episodic memory will be derived by calculating the average score from 4 separate standardised task outcomes (Zimmediate word recall accuracy + Zdelayed word recall accuracy + Zword recognition accuracy + Zpicture recognition accuracy)/4
Time frame: Baseline measure
Speed of memory
An overall score for speed of memory will be derived by calculating the average score from 2 separate standardised task outcomes (Zpicture recognition correct reaction time + Zword recognition correct reaction time)/2
Time frame: Baseline measure
Accuracy of attention
An overall score for accuracy of attention will be derived by calculating the average score from 3 separate standardised task outcomes (ZChoice reaction time accuracy + ZZRapid visual information processing accuracy + ZZDigit Vigilance accuracy)/3
Time frame: Baseline measure
Executive function
An overall score for executive function will be derived by calculating the average score from 5 separate standardised task outcomes (Znumeric working memory accuracy + ZZserial 3 subtractions accuracy + ZZserial 7 subtractions accuracy + ZStroop accuracy - ZPeg and Ball errors)/5
Time frame: Baseline measure
Speed of executive function
An overall score for speed of executive function will be derived by calculating the average score from 3 separate standardised task outcomes (Znumeric working memory correct reaction time + Zstroop correct reaction time + ZPeg and Ball overall reaction time)/3
Time frame: Baseline measure
Computerised Location learning Task
An overall score is calculated utilising the total displacement over the 5 learning trials to create a total learning index score. Scores range from 0 to 1.
Time frame: Baseline measure
Subjective overall mood disturbance
Subjective mood disturbance is derived from the overall score of the Profile of Mood States questionnaire. Higher scores indicate a greater degree of overall mood disturbance.
Time frame: Baseline measure
Subjective sleep quality
Subjective sleep quality is derived from the overall score of the Sleep Condition Indicator. Total scores ranged from 0 to 32. Higher scores are indicative of greater subjective sleep quality.
Time frame: Baseline measure
Subjective stress
Subjective stress is derived from the overall score of the Perceived Stress Scale. Higher scores are indicative of greater subjective stress
Time frame: Baseline measure
Health Outcomes
Subjective health outcomes are derived from the SF-12. Scores range from 0 to 100. Higher scores are indicative of better self-reported health.
Time frame: Baseline measure
Subjective alertness
Subjective alertness will be derived from an Alertness visual analogue scale presented following cognitive task performance. Scores range from 0 to 100. Higher scores are indicative of greater feelings of alertness.
Time frame: Baseline measure
Subjective mental fatigue
Subjective mental fatigue will be derived from a Mental Fatigue visual analogue scale presented following cognitive task performance. Scores range from 0 to 100. Higher scores are indicative of greater feelings of mental fatigue.
Time frame: Baseline measure
Global Accuracy
An overall score for global accuracy will be derived by calculating the average score from 13 separate standardised outcomes (ZChoice reaction time accuracy + ZZRapid visual information processing accuracy + ZNumeric working memory accuracy + ZZDigit Vigilance accuracy + ZStroop accuracy - ZPeg and Ball Errors + ZZSerial 3 subtractions accuracy + ZZSSerial 7 subtractions accuracy + ZPicture recognition accuracy + ZWord recognition accuracy + ZImmediate word recall accuracy + ZDelayed word recall accuracy + ZZComputerised location learning accuracy)/13
Time frame: Baseline measure
Global Speed
An overall score for global speed will be derived by calculating the average score from 8 separate standardised outcomes (ZChoice reaction time correct reaction time + ZNumeric working memory correct reaction time + ZDigit vigilance correct reaction time + ZZPeg and Ball overall reaction time + ZStroop correct reaction time + ZPicture recognition correct reaction time + ZWord recognition correct reaction time + ZRapid visual information correct reaction time) /8
Time frame: Baseline measure
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