Impact of COVID-19 restrictions on preschool children's eating, activity and sleep behaviours: a qualitative study.

OBJECTIVES: In spring 2020, the first COVID-19 national lockdown placed unprecedented restrictions on the behaviour and movements of the UK population. Citizens were ordered to 'stay at home', only allowed to leave their houses to buy essential supplies, attend medical appointments or exercise once a day. We explored how lockdown and its subsequent easing changed young children's everyday activities, eating and sleep habits to gain insight into the impact for health and well-being. DESIGN: In-depth qualitative interviews; data analysed using thematic analysis. SETTING: South West and West Midlands of England. PARTICIPANTS: Twenty parents (16 mothers; 4 fathers) of preschool-age children (3-5 years) due to start school in September 2020. Forty per cent of the sample were from Black, Asian or minority ethnic backgrounds and half lived in the most deprived areas. RESULTS: Children's activity, screen time, eating and sleep routines had been disrupted. Parents reported children ate more snacks, but families also spent more time preparing meals and eating together. Most parents reported a reduction in their children's physical activity and an increase in screen time, which some linked to difficulties in getting their child to sleep. Parents sometimes expressed guilt about changes in activity, screen time and snacking over lockdown. Most felt these changes would be temporary, though others worried about re-establishing healthy routines. CONCLUSIONS: Parents reported that lockdown negatively impacted on preschool children's eating, activity and sleep routines. While some positive changes were identified, many participants described lack of routines, habits and boundaries which may have been detrimental for child health and development. Guidance and support for families during COVID-19 restrictions could be valuable to help maintain healthy activity, eating, screen time and sleeping routines to protect child health and ensure unhealthy habits are not adopted.

Day-to-day physical activity producing low gravitational impacts is associated with faster visual processing speed at age 69: cross-sectional study.

BACKGROUND: Little is known about how different physical activity (PA) parameters relate to cognitive function in older adults. Using accelerometers calibrated to detect vertical impacts from ground reaction forces we examined the associations of low, medium and higher impact PA with processing speed, verbal memory and cognitive state in older adults. METHODS: Participants were 69-year old British men and women from the Medical Research Council National Survey of Health and Development included in a vertical impacts and bone sub-study (n = 558; 48.2% female). Counts of low (0.5 < g < 1.0 g), medium (1 < g < 1.5 g), or higher (≥1.5 g) magnitude impacts were derived from vertical acceleration peaks recorded over 7 days by hip-worn accelerometers. Processing speed was assessed by a timed visual letter search task, verbal memory by a 15-word list learning test and cognitive state by the Addenbrooke's Cognitive Examination (ACE-III). Potential confounders were childhood cognitive ability, adult socioeconomic position, body mass index and depression. RESULTS: In initial sex-adjusted models, low magnitude impacts were associated with better performance in all three cognitive function tests; standard deviation differences in test scores per doubling in number of low impacts: letter search speed = 0.10 (95% confidence intervals (CI): 0.03 to 0.16), word learning test = 0.05 (95% CI: 0.00 to 0.11), ACE-III scale = 0.09 (95% CI: 0.03 to 0.14). After adjustment for confounders, differences persisted for letter search speed (0.09; 95% CI: 0.02 to 0.16) but were closer to the null for the word learning test (0.02; 95% CI: - 0.04 to 0.07) and ACE-III scores (0.04; 95% CI: - 0.01 to 0.09). Low impacts remained associated with letter search speed after sensitivity analyses excluding those with functional and musculoskeletal problems, and after adjustment for impacts in higher bands. Modest positive associations between higher magnitude impacts and cognitive test scores were most likely due to chance. CONCLUSION: Accelerometer-derived low impact physical activity was associated with better visual processing speed in 69-year old men and women independently of childhood cognitive ability and other measured confounders. Day-to-day low impact physical activity may therefore have the potential to benefit cognitive health in older adults.

Correlates of high-impact physical activity measured objectively in older British adults.

Background: Exposure to higher magnitude vertical impacts is thought to benefit bone health. The correlates of this high-impact physical activity (PA) in later life are unknown. Methods: Participants were from the Cohort for Skeletal Health in Bristol and Avon, Hertfordshire Cohort Study and MRC National Survey of Health and Development. Associations of demographic, behavioural, physiological and psychological factors with vertical acceleration peaks ≥1.5 g (i.e. high-impact PA) from 7-day hip-worn accelerometer recordings were examined using linear regression. Results: A total of 1187 participants (mean age = 72.7 years, 66.6% females) were included. Age, sex, education, active transport, self-reported higher impact PA, walking speed and self-rated health were independently associated with high-impact PA whereas BMI and sleep quality showed borderline independent associations. For example, differences in log-high-impact counts were 0.50 (P < 0.001) for men versus women and -0.56 (P < 0.001) for worst versus best self-rated health. Our final model explained 23% of between-participant variance in high impacts. Other correlates were not associated with high-impact activity after adjustment. Conclusions: Besides age and sex, several factors were associated with higher impact PA in later life. Our findings help identify characteristics of older people that might benefit from interventions designed to promote osteogenic PA.

Physical Activity Producing Low, but Not Medium or Higher, Vertical Impacts Is Inversely Related to BMI in Older Adults: Findings From a Multicohort Study.

Background: High impact physical activity (PA) is thought to improve skeletal health, but its relation to other health outcomes are unclear. We investigated associations between PA impact magnitude and body mass index (BMI) in older adults. Methods: Data were taken from the Cohort for Skeletal Health in Bristol and Avon (COSHIBA), Hertfordshire Cohort Study, and MRC National Survey of Health and Development. Vertical acceleration peaks from 7-day hip-worn accelerometer recordings were used to classify PA as low (0.5 < g < 1.0g), medium (1 < g < 1.5g), or higher (≥1.5g) impact. Cohort-specific associations of low, medium, and higher impact PA with BMI were examined using linear regressions and estimates combined using random-effects meta-analysis. Results: A total of 1182 participants (mean age = 72.7 years, 68% female) were included. Low, medium, and higher impact PA were inversely related to BMI in initial models. After adjustment for confounders and other impacts, low, but not medium or higher, impacts were inversely related to BMI (-0.31, p < .001: overall combined standard deviation change in BMI per doubling in the number of low impacts). In adjusted analyses of body composition measured by dual-energy X-ray absorptiometry in COSHIBA, low, but not medium or higher, impacts were inversely related to total body fat mass (-0.19, p < .001) and android:gynoid fat mass ratio (-0.16, p = .01), whereas high impact PA was weakly and positively associated with lean mass (0.05, p = .06). Conclusions: Greater exposure to PA producing low magnitude vertical impacts was associated with lower BMI and fat mass at older age. Low impact PA may help reduce obesity risk in older adults.

Sarcopenia Is Negatively Related to High Gravitational Impacts Achieved From Day-to-day Physical Activity.

Background: Sarcopenia has been associated with reduced physical activity (PA). We aimed to determine if sarcopenia, and specific components of muscle size, function, and physical performance, are associated with high impacts achieved during habitual PA, as these are related to bone strength in community-dwelling older women. Methods: Participants were older women from the Cohort of Skeletal Health in Bristol and Avon. We defined sarcopenia using the EWGSOP criteria. Lower limb peak muscle power and force were assessed using Jumping Mechanography (JM). High vertical impacts were assessed by tri-axial accelerometry (at least 1.5g above gravity). Cross-sectional associations were analyzed by linear regression, adjusting for age, height and weight (or fat mass for models including appendicular lean mass index), comorbidities, smoking, alcohol, and Index of Multiple Deprivation. Results: Our analyses included 380 participants, with mean age 76.7 (SD 3.0) years; 242 (64%) also completed JM. In age-adjusted analysis, a negative relationship was observed between severity of sarcopenia and high, but not medium or low, impacts (p = .03 for trend). Regarding components of sarcopenia underlying this relationship, multivariable analyses revealed that gait speed (ß 1.47 [95% CI 1.14, 1.89], [ß-1] reflects the proportionate increase in high impacts per SD increase in exposure) and peak force (1.40 [1.07, 1.84]) were independently associated with high impacts. Conclusions: Older women with sarcopenia experienced fewer bone-strengthening high impacts than those with presarcopenia or without sarcopenia. To increase bone strengthening activity in older women, interventions need to improve both lower limb muscle force and walking speed.

Associations of lifetime walking and weight bearing exercise with accelerometer-measured high impact physical activity in later life.

High impact physical activity (PA) is thought to benefit bone. We examined associations of lifetime walking and weight bearing exercise with accelerometer-measured high impact and overall PA in later life. Data were from 848 participants (66.2% female, mean age = 72.4 years) from the Cohort for Skeletal Health in Bristol and Avon, Hertfordshire Cohort Study and MRC National Survey of Health and Development. Acceleration peaks from seven-day hip-worn accelerometer recordings were used to derive counts of high impact and overall PA. Walking and weight bearing exercise up to age 18, between 18-29, 30-49 and since age 50 were recalled using questionnaires. Responses in each age category were dichotomised and cumulative scores derived. Linear regression was used for analysis. Greater lifetime walking was related to higher overall, but not high impact PA, whereas greater lifetime weight bearing exercise was related to higher overall and high impact PA. For example, fully-adjusted differences in log-overall and log-high impact PA respectively for highest versus lowest lifetime scores were: walking [0.224 (0.087, 0.362) and 0.239 (- 0.058, 0.536)], and weight bearing exercise [0.754 (0.432, 1.076) and 0.587 (0.270, 0.904)]. For both walking and weight bearing exercise, associations were strongest in the 'since age 50' category. Those reporting the most walking and weight bearing exercise since age 50 had highest overall and high impact PA, e.g. fully-adjusted difference in log-high impact PA versus least walking and weight bearing exercise = 0.588 (0.226, 0.951). Promoting walking and weight bearing exercise from midlife may help increase potentially osteogenic PA levels in later life.

Quantifying Habitual Levels of Physical Activity According to Impact in Older People: Accelerometry Protocol for the VIBE Study.

Physical activity (PA) may need to produce high impacts to be osteogenic. The aim of this study was to identify threshold(s) for defining high impact PA for future analyses in the VIBE (Vertical Impact and Bone in the Elderly) study, based on home recordings with triaxial accelerometers. Recordings were obtained from 19 Master Athlete Cohort (MAC; mean 67.6 years) and 15 Hertfordshire Cohort Study (HCS; mean 77.7 years) participants. Data cleaning protocols were developed to exclude artifacts. Accelerations expressed in g units were categorized into three bands selected from the distribution of positive Y-axis peak accelerations. Data were available for 6.6 and 4.4 days from MAC and HCS participants respectively, with approximately 14 hr recording daily. Three-fold more 0.5-1.0g impacts were observed in MAC versus HCS, 20-fold more 1.0-1.5g impacts, and 140-fold more impacts ≥ 1.5g. Our analysis protocol successfully distinguishes PA levels in active and sedentary older individuals.

Characterization of Vertical Accelerations Experienced by Older People Attending an Aerobics Class Designed to Produce High Impacts.

The purpose of this study was to establish the feasibility of using an aerobics class to produce potentially bone protective vertical impacts of ≥ 4g in older adults and to determine whether impacts can be predicted by physical function. Participants recruited from older adult exercise classes completed an SF-12 questionnaire, short physical performance battery, and an aerobics class with seven different components, performed at low and high intensity. Maximum g and jerk values were identified for each activity. Forty-one participants (mean 69 years) were included. Mean maximal values approached or exceeded the 4g threshold for four of the seven exercises. In multivariate analyses, age (-0.53; -0.77, -0.28) (standardized beta coefficient; 95% CI) and 4-m walk time (-0.39; -0.63, -0.16) were inversely related to maximum g. Aerobics classes can be used to produce relatively high vertical accelerations in older individuals, although the outcome is strongly dependent on age and physical function.

Maternal Preeclampsia Is Associated With Reduced Adolescent Offspring Hip BMD in a UK Population-Based Birth Cohort.

A suboptimal intrauterine environment has been postulated to have adverse long-term health effects, including an increased risk of osteoporosis. Because preeclampsia (PE) and to a lesser extent gestational hypertension (GH) are associated with impaired placental function, we postulated that these represent hitherto unrecognized risk factors for reduced bone mineral density (BMD) of the offspring. The objective of this study was to investigate if exposure to PE or GH in utero is associated with BMD of the offspring as measured in late adolescence. Mother-offspring pairs from the UK population-based cohort study, Avon Longitudinal Study of Parents and Children (ALSPAC), were investigated (n = 3088 with relevant data). Multivariable linear regression was used to examine associations between PE/GH and total body, spine, and total hip BMD at age 17 years. Of the 3088 mother-offspring pairs, 2% (n = 60) of the mothers fulfilled criteria for PE and 14% (n = 416) for GH. In confounder-adjusted analyses (ie, age of scan, gender, maternal factors, including BMI, offspring height, fat mass, and lean mass), PE was negatively associated with BMD at the hip (SD difference -0.30; 95%CI, -0.50 to -0.10). This association was not attenuated by further adjustment for gestational age and birth weight, which were hypothesized to be on the causal pathway. There was also weak evidence for a negative association between PE and total body BMD (SD difference -0.17; 95% CI, -0.36 to 0.02), whereas no relationship was evident at the spine (SD difference -0.11; 95% CI, -0.30 to 0.09). In contrast, a positive association of GH with offspring total body, hip, and spine BMD attenuated to the null with adjustment for confounders, in particular confounding via the maternal and offspring adiposity/size and the link between the two. Modest negative associations from exposure to PE, but not GH may represent a hitherto unrecognized risk factor for low BMD. Further exploration of the causal relationship of the in utero environment on subsequent offspring bone health is required.

Air pollution exposure and adverse pregnancy outcomes in a large UK birth cohort: use of a novel spatio-temporal modelling technique.

OBJECTIVES: Previous work suggests an association between air pollution exposure and adverse pregnancy outcomes, even at relatively low concentrations. Our aim was to quantify the effect of air pollution having an adverse effect on preterm birth (PTB) and fetal growth in a large UK cohort using a novel exposure estimation technique [spatio-temporal (S-T) model] alongside a traditional nearest stationary monitor technique (NSTAT). METHODS: All available postcodes from a Northwest England birth outcome dataset during 2004-2008 were geocoded (N=203 562 deliveries). Pollution estimates were linked to corresponding pregnancy periods using temporally adjusted background modelled concentrations as well as NSTAT. Associations with PTB, small for gestational age (SGA), and birth weight were investigated using regression models adjusting for maternal age, ethnicity, parity, birth season, socioeconomic status (SES), body mass index (BMI), and smoking. RESULTS: Based on the novel S-T model, a small statistically significant association was observed for particulate matter (PM10) and SGA, particularly with exposure in the first and third trimesters. Similar effects on SGA were also found for nitrogen dioxide (NO 2), particulate matter (PM 2,5), and carbon monoxide (CO) in later pregnancy, but no overall increased risk was observed. No associations were found with NO xor the outcomes PTB and reduction in birth weight. CONCLUSION: Our findings suggest an association between air pollution exposure and birth of a SGA infant, particularly in the later stages of pregnancy but not with PTB or mean birth weight change.

Maternal residential proximity to sources of extremely low frequency electromagnetic fields and adverse birth outcomes in a UK cohort.

Studies have suggested that exposure to extremely low frequency electromagnetic fields (ELF-EMF) may be associated with increased risk of adverse birth outcomes. This study tested the hypothesis that close proximity to residential ELF-EMF sources is associated with a reduction in birth weight and increased the risk of low birthweight (LBW), small for gestational age (SGA) and spontaneous preterm birth (SPTB). Closest residential proximity to high voltage cables, overhead power lines, substations or towers during pregnancy was calculated for 140356 singleton live births between 2004 and 2008 in Northwest England. Associations between proximity and risk for LBW, SGA and SPTB were calculated, as well as associations with birth weight directly. Associations were adjusted for maternal age, ethnicity, parity and for part of the population additionally for maternal smoking during pregnancy. Reduced average birth weight of 212 g (95% confidence interval (CI): -395 to -29 g) was found for close proximity to a source, and was largest for female births (-251 g (95% CI: -487 to -15 g)). No statistically significant increased risks for any clinical birth outcomes with residential proximity of 50 m or less were observed. Living close (50 m or less) to a residential ELF-EMF source during pregnancy is associated with suboptimal growth in utero, with stronger effects in female than in males. However, only a few pregnant women live this close to high voltage cables, overhead power lines, substations or towers, likely limiting its public health impact.

Maternal residential proximity to major roads in north west England and adverse pregnancy outcomes.

OBJECTIVE: To investigate the effects of maternal residential proximity to major roads on adverse pregnancy outcomes. METHODS: Major road networks in North West England were linked to the maternal residence of 190,909 births (2004 to 2008). Distance between the residence and the nearest major road was calculated and dichotomized at 200 m. Logistic regression analyses were performed to investigate the association between distance to the major road with small for gestational age, low birth weight, and preterm birth. Analyses were adjusted for maternal age, ethnicity, socioeconomic status, parity, birth season, smoking, and body mass index. RESULTS: No significant associations were observed between preterm birth (odds ratio [OR] = 1.04; 95% confidence interval [CI] = 0.98 to 1.11), low birth weight (OR = 0.99; 95% CI = 0.93 to 1.05) and small for gestational age (OR = 1.00; 95% CI = 0.95 to 1.06) and living less than 200 m from a major road. CONCLUSIONS: These results, from a study with high statistical power, suggest that living less than 200 m from a major road per se does not pose any great risk of an adverse perinatal outcome. Nevertheless, it may be limited to this geographic location. Further work is needed to quantify individual pollutant effects in pregnancy.

A comparison of population air pollution exposure estimation techniques with personal exposure estimates in a pregnant cohort.

There is increasing evidence of the harmful effects for mother and fetus of maternal exposure to air pollutants. Most studies use large retrospective birth outcome datasets and make a best estimate of personal exposure (PE) during pregnancy periods. We compared estimates of personal NOx and NO2 exposure of pregnant women in the North West of England with exposure estimates derived using different modelling techniques. A cohort of 85 pregnant women was recruited from Manchester and Blackpool. Participants completed a time-activity log and questionnaire at 13-22 weeks gestation and were provided with personal Ogawa samplers to measure their NOx/NO2 exposure. PE was compared to monthly averages, the nearest stationary monitor to the participants' home, weighted average of the closest monitor to home and work location, proximity to major roads, as well as to background modelled concentrations (DEFRA), inverse distance weighting (IDW), ordinary kriging (OK), and a land use regression model with and without temporal adjustment. PE was most strongly correlated with monthly adjusted DEFRA (NO2r = 0.61, NOxr = 0.60), OK and IDW (NO2r = 0.60; NOxr = 0.62) concentrations. Correlations were stronger in Blackpool than in Manchester. Where there is evidence for high temporal variability in exposure, methods of exposure estimation which focus solely on spatial methods should be adjusted temporally, with an improvement in estimation expected to be better with increased temporal variability.

Environmental risk factors for cancers of the brain and nervous system: the use of ecological data to generate hypotheses.

BACKGROUND: There is a public health need to balance timely generation of hypotheses with cautious causal inference. For rare cancers this is particularly challenging because standard epidemiological study designs may not be able to elucidate causal factors in an early period of newly emerging risks. Alternative methodologies need to be considered for generating and shaping hypotheses prior to definitive investigation. OBJECTIVES: To evaluate whether open-access databases can be used to explore links between potential risk factors and cancers at an ecological level, using the case study of brain and nervous system cancers as an example. METHODS: National age-adjusted cancer incidence rates were obtained from the GLOBOCAN 2008 resource and combined with data from the United Nations Development Report and the World Bank list of development indicators. Data were analysed using multivariate regression models. RESULTS: Cancer rates, potential confounders and environmental risk factors were available for 165 of 208 countries. 2008 national incidences of brain and nervous system cancers were associated with continent, gross national income in 2008 and Human Development Index Score. The only exogenous risk factor consistently associated with higher incidence was the penetration rate of mobile/cellular telecommunications subscriptions, although other factors were highlighted. According to these ecological results the latency period is at least 11-12 years, but probably more than 20 years. Missing data on cancer incidence and for other potential risk factors prohibit more detailed investigation of exposure-response associations and/or explore other hypotheses. CONCLUSIONS: Readily available ecological data may be underused, particularly for the study of risk factors for rare diseases and those with long latencies. The results of ecological analyses in general should not be overinterpreted in causal inference, but equally they should not be ignored where alternative signals of aetiology are lacking.