Occupational exposure to extremely low-frequency magnetic fields and follicular lymphoma risk: a family case-control study.

OBJECTIVES: We aimed to examine the relationship between occupational exposure to extremely low-frequency magnetic fields (ELF-MFs) and follicular lymphoma (FL) risk. METHODS: We conducted a family case-control study between 2011 and 2016 in Australia and included 681 cases. Controls were either a family member of cases (related (n=294), unrelated (n=179)) or were unrelated recruited for a similarly designed Australian multiple myeloma study (n=711). We obtained detailed job histories using lifetime work calendars. We assigned exposure to ELF-MFs using an enhanced job exposure matrix, with a lag period of 10 years. We examined associations with FL risk using logistic regression accounting for relatedness between cases and controls. We performed sensitivity analyses including by control type, by sex, complete case analyses, ELF-MF exposure percentiles in addition to quartiles, ELF-MF exposure in the maximum exposed job, a shorter lag period (1 year) and the cumulative exposure in the most recent time period (1-9 years). RESULTS: We observed no association with the average intensity, duration or lifetime cumulative exposure to occupational ELF-MF exposure in the primary or sensitivity analyses. CONCLUSIONS: Our findings do not support an association between occupational ELF-MF exposure and FL risk. Although the inclusion of family members as part of the larger control group may have biased our risk estimates towards the null, findings were similar in sensitivity analyses restricted to cases and unrelated controls. Further research incorporating enhanced exposure assessment to ELF-MF is warranted to inform occupational safety regulations and any potential role in lymphomagenesis.

Physical activity and glioma: a case-control study with follow-up for survival.

PURPOSE: High-grade disease accounts for ~ 70% of all glioma, and has a high mortality rate. Few modifiable exposures are known to be related to glioma risk or mortality. METHODS: We examined associations between lifetime physical activity and physical activity at different ages (15-18 years, 19-29 years, 30-39 years, last 10 years) with the risk of glioma diagnosis, using data from a hospital-based family case-control study (495 cases; 371 controls). We followed up cases over a median of 25 months to examine whether physical activity was associated with all-cause mortality. Physical activity and potential confounders were assessed by self-administered questionnaire. We examined associations between physical activity (metabolic equivalent [MET]-h/wk) and glioma risk using unconditional logistic regression and with all-cause mortality in cases using Cox regression. RESULTS: We noted a reduced risk of glioma for the highest (≥ 47 MET-h/wk) versus lowest (< 24 METh/wk) category of physical activity for lifetime activity (OR = 0.58, 95% CI: 0.38-0.89) and at 15-18 years (OR = 0.57, 95% CI: 0.39-0.83). We did not observe any association between physical activity and all-cause mortality (HR for lifetime physical activity = 0.91, 95% CI: 0.64-1.29). CONCLUSION: Our findings are consistent with previous research that suggested physical activity during adolescence might be protective against glioma. Engaging in physical activity during adolescence has many health benefits; this health behavior may also offer protection against glioma.

Long term all-cause and cardiovascular disease mortality among women who undergo fertility treatment.

OBJECTIVES: To compare age-adjusted all-cause and CVD mortality, relative to the general female population, for women registered for fertility treatment who received it and those who did not. DESIGN: Prospective cohort study; analysis of Monash IVF clinical registries data, 1975-2018, linked with National Death Index mortality data. PARTICIPANTS: All women who registered for fertility treatment at Monash IVF (Melbourne, Victoria), 1 January 1975 - 1 January 2014, followed until 31 December 2018. MAIN OUTCOME MEASURES: Standardised mortality ratios (SMRs) for all-cause and CVD mortality, for women who did or did not undergo fertility treatment; SMRs stratified by area-level socio-economic disadvantage (SEIFA Index of Relative Socioeconomic Disadvantage [IRSD]) and (for women who underwent treatment), by stimulated cycle number and mean oocytes/cycle categories. RESULTS: Of 44 149 women registered for fertility treatment, 33 520 underwent treatment (66.4%), 10 629 did not. After adjustment for age, both all-cause (SMR, 0.58; 95% CI, 0.54-0.62) and CVD mortality (SMR, 0.41; 95% CI, 0.32-0.53) were lower than for the general female population. All-cause mortality was similar for women registered with Monash IVF who did (SMR, 0.55; 95% CI, 0.50-0.60) or did not undergo fertility treatment (SMR, 0.63; 95% CI, 0.56-0.70). The SMR was lowest for both treated and untreated women in the fifth IRSD quintile (least disadvantage), but the difference was statistically significant only for untreated women. CVD mortality was lower for registered women who underwent fertility treatment (SMR, 0.29; 95% CI, 0.19-0.43) than for those who did not (SMR, 0.58; 95% CI, 0.42-0.81). CONCLUSION: Fertility treatment does not increase long term all-cause or CVD mortality risk. Lower mortality among women registered for fertility treatment probably reflected their lower socio-economic disadvantage.

Modifiable lifestyle risk factors and survival after diagnosis with multiple myeloma.

BACKGROUND: While remaining incurable, median overall survival for MM now exceeds 5 years. Yet few studies have investigated how modifiable lifestyle factors influence survival. We investigate whether adiposity, diet, alcohol, or smoking are associated with MM-related fatality. RESEARCH DESIGN AND METHODS: We recruited 760 incident cases of MM via cancer registries in two Australian states during 2010-2016. Participants returned questionnaires on health and lifestyle. Follow-up ended in 2020. Flexible parametric survival models were used to estimate hazard ratios (HR) and 95% confidence intervals (CI) for lifestyle exposures and risk of all-cause and MM-specific fatality. RESULTS: Higher pre-diagnosis Alternative Healthy Eating Index (AHEI) scores were associated with reduced MM-specific fatality (per 10-unit score, HR = 0.84, 95%CI = 0.70-0.99). Pre-diagnosis alcohol consumption was inversely associated with MM-specific fatality, compared with nondrinkers (0.1-20 g per day, HR = 0.59, 95%CI = 0.39-0.90; >20 g per day, HR = 0.67, 95%CI = 0.40-1.13). Tobacco smoking was associated with increased all-cause fatality compared with never smoking (former smokers: HR = 1.44, 95%CI = 1.10-1.88; current smokers: HR = 1.30, 95%CI = 0.80-2.10). There was no association between pre-enrollment body mass index (BMI) and MM-specific or all-cause fatality. CONCLUSIONS: Our findings support established recommendations for healthy diets and against smoking. Higher quality diet, as measured by the AHEI, may improve survival post diagnosis with MM.

Alcohol and tobacco use and risk of multiple myeloma: A case-control study.

Multiple myeloma (MM) is the second most common hematological cancer and causes significant mortality and morbidity. Knowledge regarding modifiable risk factors for MM remains limited. This analysis of an Australian population-based case-control family study investigates whether smoking or alcohol consumption is associated with risk of MM and related diseases. Incident cases (n = 789) of MM were recruited via cancer registries in Victoria and New South Wales. Controls (n = 1,113) were either family members of cases (n = 696) or controls recruited for a similarly designed study of renal cancers (n = 417). Adjusted odds ratios (OR) and 95% confidence intervals (CI) were estimated using unconditional multivariable logistic regression. Heavy intake (>20 g ethanol/day) of alcohol had a lower risk of MM compared with nondrinkers (OR = 0.68, 95% CI: 0.50-0.93), and there was an inverse dose-response relationship for average daily alcohol intake (OR per 10 g ethanol per day = 0.92, 95% CI: 0.86-0.99); there was no evidence of an interaction with sex. There was no evidence of an association with MM risk for smoking-related exposures (p > 0.18). The associations between smoking and alcohol with MM are similar to those with non-Hodgkin lymphoma. Further research into potential underlying mechanisms is warranted.

Looking back in time: conducting a cohort study of the long-term effects of treatment of adolescent tall girls with synthetic hormones.

OBJECTIVE: Public health research is an endeavour that often involves multiple relationships, far-reaching collaborations, divergent expectations and various outcomes. Using the Tall Girls Study as a case study, this paper will present and discuss a number of methodological, ethical and legal challenges that have implications for other public health research. APPROACH: The Tall Girls Study was the first study to examine the long-term health and psychosocial effects of oestrogen treatment for tall stature. RESULTS: In undertaking this study the research team overcame many hurdles: in maintaining collaboration with treating clinicians and with the women they had treated as girls - groups with opposing points of view and different expectations; using private practice medical records to trace women who had been patients up to forty years earlier; and exploring potential legal issues arising from the collection of data related to treatment. CONCLUSION: While faced with complex challenges, the Tall Girls Study demonstrated that forward planning, ongoing dialogue between all stakeholders, transparency of processes, and the strict adherence to group-developed protocols were keys to maintaining rigour while undertaking pragmatic research. IMPLICATIONS: Public health research often occurs within political and social contexts that need to be considered in the planning and conduct of studies. The quality and acceptability of research findings is enhanced when stakeholders are engaged in all aspects of the research process.

Domain-Specific Physical Activity, Pain Interference, and Muscle Pain after Activity.

PURPOSE: Using the Melbourne Collaborative Cohort Study, we examined the associations of occupation, household, transport, and leisure physical activity with pain interference with normal work and muscle pain after activity. METHODS: This cross-sectional analysis included 7655 working and 11,766 nonworking participants. Physical activity was assessed using the long-form International Physical Activity Questionnaire. Pain interference was assessed with the Short-Form 12-Item Health Survey version 2.0, and muscle pain after activity was assessed using the 12-item Somatic and Psychological Health Report. Ordered logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (CI), and restricted cubic splines were used to graphically represent the shape of associations. RESULTS: All physical activity domain-pain outcome associations were nonlinear. Compared with participants who reported the lowest level of activity, participants who reported the median level of transport physical activity (10 MET·h·wk) reported less pain interference (workers: OR, 0.86 [95% CI, 0.77-0.97]; nonworkers: OR, 0.88 [95% CI, 0.79-0.97]) and muscle pain after activity (workers: OR, 0.81 [95% CI, 0.70-0.95]; nonworkers: OR, 0.86 [95% CI, 0.77-0.95]). Higher levels of leisure time activity (20 MET·h·wk) were associated with less pain interference in nonworkers (OR, 0.87; 95% CI, 0.77-0.98) and muscle pain after activity in workers (OR, 0.67; 95% CI, 0.56-0.80). Workers who reported the median level of household activity (16 MET·h·wk) had increased pain interference (OR, 1.19; 95% CI, 1.07-1.32) and muscle pain after activity (OR, 1.23; 95% CI, 1.06-1.42) than did those who reported the least household activity. CONCLUSIONS: Associations between domain-specific physical activity and pain outcomes were not uniform. Within the transport and leisure domains, physical activity was inversely associated with pain-related outcomes, whereas household physical activity was positively associated with pain scores within the working sample.

A quantitative bias analysis to estimate measurement error-related attenuation of the association between self-reported physical activity and colorectal cancer risk.

BACKGROUND: Self-reported physical activity is inaccurate, yet few investigators attempt to adjust for measurement error when estimating risks for health outcomes. We estimated what the association between self-reported physical activity and colorectal cancer risk would be if physical activity had been assessed using accelerometry instead. METHODS: We conducted a validation study in which 235 Australian adults completed a telephone-administered International Physical Activity Questionnaire (IPAQ), and wore an accelerometer (Actigraph GT3X+) for 7 days. Using accelerometer-assessed physical activity as the criterion measure, we calculated validity coefficients and attenuation factors using a structural equation model adjusted for age, sex, education and body mass index. We then used a regression calibration approach to apply the attenuation factors to data from the Melbourne Collaborative Cohort Study (MCCS) to compute bias-adjusted hazard ratios (HR) and 95% confidence intervals (CI). RESULTS: Average daily minutes of physical activity from the short form of the International Physical Activity Questionnaire (IPAQ-short) were substantially higher than accelerometer-measured duration (55 versus 32 min). The validity coefficient (0.32; 95% CI: 0.20, 0.43) and attenuation factor (0.20; 95% CI: 0.12, 0.28) were low. The HRs for colorectal cancer risk for high (75th percentile; 411 min/week) versus low (25th percentile; 62 min/week) levels of self-reported physical activity were 0.95 (95% CI: 0.87, 1.05) before and 0.78 (95% CI: 0.47, 1.28) after bias adjustment. CONCLUSIONS: Over-estimation of physical activity by the IPAQ-short substantially attenuates the association between physical activity and colorectal cancer risk, suggesting that the protective effect of physical activity has been previously underestimated.

The utility of DNA extracted from saliva for genome-wide molecular research platforms.

OBJECTIVE: The study aimed to investigate the suitability of DNA extracted from saliva for high throughput molecular genotyping and DNA methylation platforms by comparing its performance with that of DNA extracted from blood. The genome-wide methylation profile, using the Infinium HumanMethylation450 Beadchip array® (Illumina, San Diego, CA), was measured for 20 DNA samples. Common genetic variation was measured, using the Infinium HumanCore Beadchip® (Illumina, San Diego, CA) for 4 samples (matching samples from 2 people). RESULTS: DNA from blood and saliva returned genotyping call rates and reproducibility frequencies of > 99%. High-quality DNA methylation data was obtained from both saliva and blood DNA, with average detection p-values for each sample ranging from 0.001 to 0.006. Slightly higher global DNA methylation levels were observed in whole blood DNA than saliva DNA. Correlations between individuals for each sample type were generally greater than correlations between two sample types from the same individual (Pearson's correlation, r = 0.9696 in 10 pairs of matched blood and saliva derived DNA, r = 0.9702 between saliva samples, and r = 0.9769 between blood derived DNA). Saliva yields DNA of sufficient quantity and quality to compare favourably with blood as a source of DNA for genetic and epigenetic research purposes.

Adolescent exposure to high-dose estrogen and subsequent effects on lactation.

Treatment with high-dose estrogens has been used to reduce the adult height of tall girls for many years. Short-term side effects on the breast have been reported but there have been no studies to investigate whether there are long-term effects on lactation. This retrospective cohort study of 371 treated and 409 untreated women asked about breastfeeding history. After adjusting for maternal age at first live-birth, treated women (4.4%) were no more likely than untreated women (4.1%) to not commence breastfeeding (RR 1.13, 95% CI 0.50-2.52). After adjusting for age, there was no significant difference in the average duration of breastfeeding between treated (median 41.1 weeks) and untreated women (median 43.3 weeks) (p=0.77) for all live-births. Treated women were not significantly more likely to report physiological reasons for stopping breastfeeding than untreated women. Women treated with high-dose estrogens during adolescence appeared to be no different to untreated women in their ability to lactate.

Concern about tall stature during adolescence and depression in later life.

OBJECTIVE: This retrospective cohort study aimed to examine the long-term psychosocial outcomes for women assessed or treated during adolescence for tall stature. METHOD: Women assessed or treated for tall stature identified from the records of Australian paediatricians were eligible to participate. Psychosocial outcomes were measured using the depression, mania and eating disorders modules of the Composite International Diagnostic Interview (CIDI), the SF-36, and an index of social support. RESULTS: There was no significant difference between treated and untreated women in the prevalence of 12 month or lifetime major depression, eating disorders, scores on the SF-36 mental health summary scale, or the index of social support. However, compared with the findings of population-based studies, the prevalence of major depression in both treated and untreated tall girls was high (12 month prevalence: untreated 10.7%, treated 11.2%; lifetime prevalence: untreated 29.4%, treated 26.6%). Factors significantly associated with lifetime major depression in this study were self-reported difficulties during adolescence being the reason for seeking a medical assessment of height (OR 2.25, 95% CI 1.4-3.6) and a negative experience of the assessment or treatment procedures (OR 2.04, 95% CI 1.4-3.0). CONCLUSION: Long-term follow-up of a large cohort of tall girls showed that psychological outcomes among both treated and untreated women were poor and that the intended psychosocial benefit of treatment may not have been realized. The findings highlight the importance of attending to the mental health of adolescents presenting for management of conditions where self-concept and body image are a primary focus.

Women's views and experiences of postnatal hospital care in the Victorian Survey of Recent Mothers 2000.

OBJECTIVE: To investigate the views and experiences of postnatal hospital care of a representative sample of Victorian women who gave birth in Victoria, Australia, in 1999. DESIGN: Postal survey sent to women 5-6 months after giving birth. SETTING: Victoria, Australia. PARTICIPANTS: 1616 women who gave birth in Victoria in a 2-week period in September 1999. FINDINGS: 50.8% of women described their postnatal care in hospital as 'very good'. After adjusting for parity, method of birth, length of stay, model of care and socio-demographic characteristics, specific aspects of care with the greatest negative impact on the overall rating of postnatal care were as follows: midwives perceived as rushed and too busy (adjusted OR = 4.59 [95% CI 3.4-6.1]), doctors and midwives perceived as not 'always' sensitive and understanding (adjusted OR = 3.88 [2.8-5.5]), support and advice about going home not 'very helpful' (adjusted OR = 3.18 [2.3-4.5]), help and advice about baby feeding not 'extremely helpful' (adjusted OR = 3.27 [2.1-5.1]), not being given advice about baby feeding (adjusted OR = 2.84 [1.2-6.9]). Staying in hospital only 1-2 days (adjusted OR=2.00 [1.2-3.4]), and not knowing any of the midwives in the postnatal ward (adjusted OR = 1.80 [1.3-2.4]) were also associated with less positive ratings of postnatal hospital care. KEY CONCLUSIONS AND IMPLICATIONS FOR PRACTICE: The 2000 Survey shows that women rate early postnatal care in hospital far less favourably than care in pregnancy, labour and birth. The findings indicate that interactions with caregivers are a major influence on women's overall rating of postnatal hospital care. Acting on these findings requires a greater focus on communication and listening skills, attention to staffing levels, and leadership promoting more women-centred care in postnatal wards.