title: Female athlete health: The silent risks of high performance

authors: MacKay, Kelsi

abstract: Despite female athlete health becoming a growing area of interest in sport science reasearch, there are still gaps to be filled in the literature. Low energy availabilty (LEA) and iron deficiency are two prevalent issues in women (or female athletes)  that are under high loads of exercise stress from training. Thus, it is critical that measurement and identification of these parameters is accurate. The first part of this thesis reviews the literature surrounding LEA and iron deficiency with a focus on current identification techniques used in research and clinical settings. The second part of this thesis includes two original investigations. The first study, Chapter 2, had two aims; 1) to investigate the test-retest reliabilty of an indirect calorimetry analyser (Parvo Medics TrueOne), and 2) compare measured RMR with three RMR-predictive (pRMR) equations in female athletes. To address the first aim, 12 recreationally-exercising women (mean ± SD; age 27.5 ± 12.3 y) performed two RMR assessments, on separate days, utilising the Parvo Medics TrueOne analyser. To address the second aim, 25 females (mean ± SD; age 30.1 ± 10.2 y) underwent an RMR assessment using the Parvo Medics TrueOne analyser, which was compared to three calculated pRMR equations (Harris-Benedict [H-B], Mifflin-St Jeor [M], World Health Organisation [WHO]). Test-retest reliability for the TrueOne analyser was deemed acceptable (CV = 5.3%, ICC = 0.92). The validity of pRMR when compared to measured RMR showed low levels of agreement in all 3 predictive equations (M: CV = 21.4%, TEE = 269 kcal•day⁻¹, r = 0.16, WHO: CV = 21.5%, TEE = 270 kcal•day⁻¹, r = 0.13 H-B: CV = 21.6%, TEE = 270 kcal•day⁻¹, r = 0.13).  
The second study, Chapter 3, was designed to investigate specific health parameters related to iron, resting metabolic rate and energy balance in a cohort of highly-trained women. Thirteen highly-trained female endurance athletes (mean ± SD; age 32 ± 7 y, training volume 18.5 ± 4.1 hrs) provided a blood test to assess iron markers (haemoglobin [Hb], haematocrit [Hct], C-reactive protein [Crp], serum iron, serum ferritin and transferrin). Additional measures included resting metabolic rate (RMR) assessment, dual-energy x-ray absorptiometry (DXA) scans, diet and training diaries and menstrual cycle tracking to identify any additional risk factors which may be associated with relative energy deficiency in sport. Analysis revealed that 46% (6/13) of this population had iron levels below optimal. Serum iron, serum ferritin and transferrin were all significantly decreased in the iron deficient (ID) group (p < 0.05). When compared to the non-iron deficient (non-ID) group haemoglobin (Hb) and haematocrit (Hct) were significantly lower in the ID group compared with the non-ID group (p < 0.05). The relationship between Crp and serum iron revealed a large negative correlation (r = -0.66), Crp and serum ferritin a very large negative correlation (r = -0.72) and transferrin presented a large correlation with Crp (r = 0.70). In conclusion, the outcomes of these studies demonstrate the need for greater stratification of risk thresholds for this (emerging) group of highly-trained, non-professional female athletes.

text: Female athlete health: The silent risks of high performance Despite female athlete health becoming a growing area of interest in sport science reasearch, there are still gaps to be filled in the literature. Low energy availabilty (LEA) and iron deficiency are two prevalent issues in women (or female athletes)  that are under high loads of exercise stress from training. Thus, it is critical that measurement and identification of these parameters is accurate. The first part of this thesis reviews the literature surrounding LEA and iron deficiency with a focus on current identification techniques used in research and clinical settings. The second part of this thesis includes two original investigations. The first study, Chapter 2, had two aims; 1) to investigate the test-retest reliabilty of an indirect calorimetry analyser (Parvo Medics TrueOne), and 2) compare measured RMR with three RMR-predictive (pRMR) equations in female athletes. To address the first aim, 12 recreationally-exercising women (mean ± SD; age 27.5 ± 12.3 y) performed two RMR assessments, on separate days, utilising the Parvo Medics TrueOne analyser. To address the second aim, 25 females (mean ± SD; age 30.1 ± 10.2 y) underwent an RMR assessment using the Parvo Medics TrueOne analyser, which was compared to three calculated pRMR equations (Harris-Benedict [H-B], Mifflin-St Jeor [M], World Health Organisation [WHO]). Test-retest reliability for the TrueOne analyser was deemed acceptable (CV = 5.3%, ICC = 0.92). The validity of pRMR when compared to measured RMR showed low levels of agreement in all 3 predictive equations (M: CV = 21.4%, TEE = 269 kcal•day⁻¹, r = 0.16, WHO: CV = 21.5%, TEE = 270 kcal•day⁻¹, r = 0.13 H-B: CV = 21.6%, TEE = 270 kcal•day⁻¹, r = 0.13).  
The second study, Chapter 3, was designed to investigate specific health parameters related to iron, resting metabolic rate and energy balance in a cohort of highly-trained women. Thirteen highly-trained female endurance athletes (mean ± SD; age 32 ± 7 y, training volume 18.5 ± 4.1 hrs) provided a blood test to assess iron markers (haemoglobin [Hb], haematocrit [Hct], C-reactive protein [Crp], serum iron, serum ferritin and transferrin). Additional measures included resting metabolic rate (RMR) assessment, dual-energy x-ray absorptiometry (DXA) scans, diet and training diaries and menstrual cycle tracking to identify any additional risk factors which may be associated with relative energy deficiency in sport. Analysis revealed that 46% (6/13) of this population had iron levels below optimal. Serum iron, serum ferritin and transferrin were all significantly decreased in the iron deficient (ID) group (p < 0.05). When compared to the non-iron deficient (non-ID) group haemoglobin (Hb) and haematocrit (Hct) were significantly lower in the ID group compared with the non-ID group (p < 0.05). The relationship between Crp and serum iron revealed a large negative correlation (r = -0.66), Crp and serum ferritin a very large negative correlation (r = -0.72) and transferrin presented a large correlation with Crp (r = 0.70). In conclusion, the outcomes of these studies demonstrate the need for greater stratification of risk thresholds for this (emerging) group of highly-trained, non-professional female athletes.

year: 2018

title: Against epistocracy

authors: Munn, Nicholas

abstract: There has been a recent resurgence in epistocratic arguments against our democratic institutions. Jason Brennan (2009, 2011, 2016) is a popular representative of the approach. Here, I criticise Brennan’s account and offer an alternative analysis of modern democratic societies. I argue that Brennan has not shown that the currently enfranchised are relevantly incompetent such that they ought to be excluded from the franchise. Further, even had he shown this, his proposed solution suffers from the same injustices he diagnoses in democracies. I consider an alternative means of embracing a restrictive franchise.

text: Against epistocracy There has been a recent resurgence in epistocratic arguments against our democratic institutions. Jason Brennan (2009, 2011, 2016) is a popular representative of the approach. Here, I criticise Brennan’s account and offer an alternative analysis of modern democratic societies. I argue that Brennan has not shown that the currently enfranchised are relevantly incompetent such that they ought to be excluded from the franchise. Further, even had he shown this, his proposed solution suffers from the same injustices he diagnoses in democracies. I consider an alternative means of embracing a restrictive franchise.

year: 2018

title: How differing methods of ascribing ethnicity and socio-economic status affect risk estimates for hospitalisation with infectious disease

authors: Hobbs, Mark R.

subjects: Ethnicity/race

abstract: Significant ethnic and socio-economic disparities exist in infectious diseases (IDs) rates in New Zealand, so accurate measures of these characteristics are required. This study compared methods of ascribing ethnicity and socio-economic status. Children in the Growing Up in New Zealand longitudinal cohort were ascribed to self-prioritised, total response and single-combined ethnic groups. Socio-economic status was measured using household income, and both census-derived and survey-derived deprivation indices. Rates of ID hospitalisation were compared using linked administrative data. Self-prioritised ethnicity was simplest to use. Total response accounted for mixed ethnicity and allowed overlap between groups. Single combined ethnicity required aggregation of small groups to maintain power but offered greater detail. Regardless of the method used, Māori and Pacific children, and children in the most socio-economically deprived households had a greater risk of ID hospitalisation. Risk differences between self-prioritised and total response methods were not significant for Māori and Pacific children but single-combined ethnicity revealed a diversity of risk within these groups. Household income was affected by non-random missing data. The census derived deprivation index offered a high level of completeness with some risk of multicollinearity and concerns regarding the ecological fallacy. The survey-derived index required extra questions but was acceptable to participants and provided individualised data. Based on these results, the use of single-combined ethnicity and an individualised survey-derived index of deprivation are recommended where sample size and data structure allow it.

text: How differing methods of ascribing ethnicity and socio-economic status affect risk estimates for hospitalisation with infectious disease Significant ethnic and socio-economic disparities exist in infectious diseases (IDs) rates in New Zealand, so accurate measures of these characteristics are required. This study compared methods of ascribing ethnicity and socio-economic status. Children in the Growing Up in New Zealand longitudinal cohort were ascribed to self-prioritised, total response and single-combined ethnic groups. Socio-economic status was measured using household income, and both census-derived and survey-derived deprivation indices. Rates of ID hospitalisation were compared using linked administrative data. Self-prioritised ethnicity was simplest to use. Total response accounted for mixed ethnicity and allowed overlap between groups. Single combined ethnicity required aggregation of small groups to maintain power but offered greater detail. Regardless of the method used, Māori and Pacific children, and children in the most socio-economically deprived households had a greater risk of ID hospitalisation. Risk differences between self-prioritised and total response methods were not significant for Māori and Pacific children but single-combined ethnicity revealed a diversity of risk within these groups. Household income was affected by non-random missing data. The census derived deprivation index offered a high level of completeness with some risk of multicollinearity and concerns regarding the ecological fallacy. The survey-derived index required extra questions but was acceptable to participants and provided individualised data. Based on these results, the use of single-combined ethnicity and an individualised survey-derived index of deprivation are recommended where sample size and data structure allow it.

year: 2019