Addressing the influence of the alcohol industry in Aotearoa New Zealand.

Alcohol legislation in Aotearoa New Zealand has not been sufficient to minimise the harm and inequities caused by alcohol use, and a comprehensive review of alcohol policies has been postponed. Because of the alcohol industry's vested interests, the World Health Organization notes that industry involvement in public health policy has potential risks that should be minimised. Here we illustrate the significant extent of alcohol industry penetration in Aotearoa and how such influence undermines equity by amplifying the harms of colonisation. The government lacks policies that limit interactions with the alcohol industry, such as political donations and lobbying. We recommend what can be done to limit alcohol industry influence in policymaking, including using experiences in tobacco control to manage conflicts of interest, strengthening rules over political donations and lobbying, enhancing transparency of interactions, promoting non-collaboration with the alcohol industry and advocating for alcohol policies that give effect to Te Tiriti o Waitangi.

Effective alcohol policies are associated with reduced consumption among demographic groups who drink heavily.

BACKGROUND: Alcohol policies stand out among other noncommunicable disease-relevant policies for the lack of uptake. Composite indicators have been developed to measure the effects of alcohol control policy. We investigated whether drinking patterns among demographic groups from general population samples of drinkers from diverse countries are associated with alcohol control policy as measured by the International Alcohol Control (IAC) Policy Index. METHODS: Representative samples of adult drinkers from 10 countries (five high-income and five middle-income) were surveyed about alcohol consumption, using beverage and location-specific questions. MEASUREMENTS: The IAC Policy Index was analyzed with frequency, typical occasion quantity, and volume consumed. Analyses used mixed models that included interactions between country IAC Policy Index score and age group, gender, and education level. FINDINGS: Each increase in IAC policy index score (reflecting more effective alcohol policy) was associated with a 13.9% decrease in drinking frequency (p = 0.006) and a 16.5% decrease in volume (p = 0.001). With each increase in IAC Policy Index score, both genders decreased for all three measures, but men less so than women. Women decreased their typical occasion quantity by 1.2% (p = 0.006), frequency by 3.1% (p < 0.001), and total volume by 4.2% (p < 0.001) compared to men. Low and mid-education groups decreased their typical occasion quantity by 2.6% (p < 0.001) and 1.6% (p = 0.001), respectively, compared to high education, while for drinking frequency the low education group increased by 7.0% (p < 0.001). There was an overall effect of age (F = 19.27, p < 0.0001), with 18-19 and 20-24-year-olds showing the largest decreases in typical occasion quantity with increasing IAC policy index score. CONCLUSIONS: The IAC Policy Index, reflecting four effective policies, was associated with volume and frequency of drinking across 10 diverse countries. Each increase in the IAC Policy Index was associated with lower typical quantities consumed among groups reporting heavy drinking: young adults and less well-educated. There is value in implementing such alcohol policies and a need to accelerate their uptake globally.

Effective alcohol policies and lifetime abstinence: An analysis of the International Alcohol Control policy index.

INTRODUCTION: Alcohol abstinence remains common among adults globally, although low and middle-income countries are experiencing declines in abstention. The effect of alcohol policies on lifetime abstinence is poorly understood. The International Alcohol Control (IAC) policy index was developed to benchmark and monitor the uptake of effective alcohol policies and has shown strong associations with alcohol per capita consumption and drinking patterns. Uniquely, the index incorporates both policy 'stringency' and 'impact', reflecting policy implementation and enforcement, across effective policies. Here we assessed the association of the IAC policy index with lifetime abstinence in a diverse sample of jurisdictions. METHODS: We conducted a cross-sectional analysis of the relationship between the IAC policy index score, and its components, and lifetime abstinence among adults (15+ years) in 13 high and middle-income jurisdictions. We examined the correlations for each component of the index and stringency and impact separately. RESULTS: Overall, the total IAC policy index scores were positively correlated with lifetime abstinence (r = 0.76), as were both the stringency (r = 0.62) and impact (r = 0.82) scores. Marketing restrictions showed higher correlations with lifetime abstinence than other policy domains (r = 0.80), including restrictions on physical availability, pricing policies and drink-driving prevention. DISCUSSION AND CONCLUSION: Our findings suggest that restricting alcohol marketing could be an important policy for the protection of alcohol abstention. The IAC policy index may be a useful tool to benchmark the performance of alcohol policy in supporting alcohol abstention in high and middle-income countries.

The impact of alcohol pricing policies on public health in Hong Kong, China: A modelling study.

Background: Contrary to most developed economies, Hong Kong has reduced and eliminated taxes on beer and wine over the last 15 years and observed increasing alcohol consumption. Methods: We applied econometric epidemiological modelling to assess the impact of reverting ad valorem taxation to pre-2008 levels (20% on wine and 40% on beer) on consumption and health outcomes. We used 15 years of industry sales and pricing data (2004-2018) to derive 25 own-price and cross-price elasticity estimates. We applied risk functions from the World Health Organization 2018 Global Status Report to assess the impact on 25 alcohol-attributable conditions. Findings: An estimated 616 deaths (91.3% in men) were attributable to alcohol in 2018. Raising taxes to pre-2008 levels is estimated to reduce consumption of pure alcohol consumption by 8.0%, 15.9%, and 31.1%; and reduce alcohol-attributable deaths by 11.6%, 21.8%, and 40.2% assuming 25%, 50% and 100% pass through rates of taxes to consumers. The largest projected decreases in alcohol-attributable mortality in absolute numbers are alcohol abuse, alcohol dependence, and alcoholic psychoses (wholly alcohol-attributable disorders). The largest absolute number of new alcohol-attributable cases in 2018 were hypertension, alcohol dependence and alcohol abuse; which are estimated to be reduced by 31.3%, 34.2%, and 34.3% respectively by raising taxes to pre-2008 levels. The alcohol-attributable health burden and absolute reductions in health harms are far greater in men. Interpretation: Reversing the 2008 alcohol tax reductions is potentially effective in averting the alcohol-attributable health burden and thus mitigate against the avoidable harms of alcohol-related disease. Funding: Health and Medical Research Fund, Food and Health Bureau of the Hong Kong SAR, China [03170067].

The impact of road safety policies in a deregulated alcohol tax environment in Hong Kong: a 15-year time series analysis.

BACKGROUND AND AIMS: Hong Kong reduced beer and wine tax in 2007, eliminated taxes on beer and wine and strengthened drink-driving legislation in 2008, and increased police traffic enforcement after the 2014 social unrest. This study aimed to measure the effects of implementing road safety policies on road traffic harm in the context of deregulated alcohol control policy in Hong Kong. DESIGN: Population-based interrupted time series analysis using seasonal autoregressive integrated moving average (sARIMA) models. Multiple sensitivity analyses were conducted. SETTING: Hong Kong, China and Singapore from January 2004 to December 2019. CASES: A total of 313 728 road traffic injuries in Hong Kong and 163 773 road traffic injuries in Singapore as controls. MEASUREMENTS: Monthly rates of road traffic injuries, non-fatal injuries and serious/fatal injuries from Hong Kong and Singapore Police Force. FINDINGS: The elimination of alcohol taxes and the enactment of road safety legislation in 2008 were associated with immediate reductions in total road traffic injuries of 6.71% (95% CI, 1.99%-11.20%), serious/fatal injuries of 13.80% (95% CI, 1.85%-24.30%) and sustained declines in drink-driving and collisions involving drink-driving. The effects of the 2007 tax reduction were inconclusive. Progressively increasing traffic enforcement was associated with continuous reductions in road traffic injuries by 0.21% per month (95% CI, 0.13%-0.30%), and serious/fatal injuries by 1.10% per month (95% CI, 0.85%-1.35%). Effects at the corresponding timepoints in Singapore did not reach statistical significance; the results were inconclusive regarding confounding effects on both regions. CONCLUSIONS: Despite weakened alcohol control and increased alcohol sales over the same period, road safety policies in Hong Kong are associated with net reductions in road traffic injuries, particularly serious/fatal injuries.

Benchmarking alcohol policy based on stringency and impact: The International Alcohol Control (IAC) policy index.

This study developed a measurement tool to assess stringency and 'on-the-ground' impact of four key alcohol policy domains to create an alcohol policy index suitable for benchmarking alcohol policy and assessing change over time in middle- and high-income countries. It involved a collaboration between researchers in 12 diverse countries: New Zealand; Australia; England; Scotland; Netherlands; Vietnam; Thailand; South Africa; Turkey; Chile; Saint Kitts and Nevis and Mongolia. Data on the four most effective alcohol policy domains (availability, pricing policy, alcohol marketing, drink driving) were used to create an alcohol policy index based on their association with alcohol per capita consumption (APC) of commercial (recorded) alcohol. An innovation was the inclusion of measures of impact along with the stringency of the legislation or regulation. The resulting International Alcohol Control (IAC) Policy Index showed a very high negative correlation (-0.91) with recorded APC. Greater affordability of alcohol, an impact measure taking into account prices paid and countries' Gross Domestic Product, was predictive of higher APC (-0.80). Countries in which more modes of alcohol marketing are legally allowed and used had higher APC. Legislation on outlet density and drink driving predicted APC whereas trading hours did not. While stringency and impact measures varied between domains in terms of relationship with APC, overall, there was a strong correlation between impact and stringency (0.77). The IAC Policy Index, which includes measures of policy stringency and 'on-the-ground' impacts in relation to four key policy areas, was found to be strongly associated with commercial alcohol consumed in a number of diverse country settings. It showed a larger relationship than previous indices that include more policy dimensions. The index provides a relatively simple tool for benchmarking and communication with policy makers to encourage a strong focus on uptake of these four most effective alcohol policies.

Management of Conflicts of Interest in WHO's Consultative Processes on Global Alcohol Policy.

BACKGROUND: The World Health Organization (WHO) has engaged in consultations with the alcohol industry in global alcohol policy development, including currently a draft action plan to strengthen implementation of the Global strategy to reduce the harmful use of alcohol. WHO's Framework for Engagement with Non-State Actors (FENSA) is an organization-wide policy that aims to manage potential conflicts of interest in WHO's interactions with private sector entities, non-governmental institutions, philanthropic foundations and academic institutions. METHODS: We analysed the alignment of WHO's consultative processes with non-state actors on "the way forward" for alcohol policy and a global alcohol action plan with FENSA. We referred to publicly accessible WHO documents, including the Alcohol, Drugs and Addictive Behaviours Unit website, records of relevant meetings, and other documents relevant to FENSA. We documented submissions to two web-based consultations held in 2019 and 2020 by type of organization and links to the alcohol industry. RESULTS: WHO's processes to conduct due diligence, risk assessment and risk management as required by FENSA appeared to be inadequate. Limited information was published on non-state actors, primarily the alcohol industry, that participated in the consultations, including their potential conflicts of interest. No minutes were published for WHO's virtual meeting with the alcohol industry, suggesting a lack of transparency. Organizations with known links to the tobacco industry participated in both web-based consultations, despite FENSA's principle of non-engagement with tobacco industry actors. CONCLUSION: WHO's consultative processes have not been adequate to address conflicts of interest in relation to the alcohol industry, violating the principles of FENSA. Member states must ensure that WHO has the resources to implement and is held accountable for appropriate and consistent safeguards against industry interference in the development of global alcohol policy.

Effect of Berberine on Cardiovascular Disease Risk Factors: A Mechanistic Randomized Controlled Trial.

Cardiovascular disease (CVD) is a major contributor to the global burden of disease. Berberine, a long-standing, widely used, traditional Chinese medicine, is thought to have beneficial effects on CVD risk factors and in women with polycystic ovary syndrome. The mechanisms and effects, specifically in men, possibly via testosterone, have not been examined previously. To assess the effect of berberine on CVD risk factors and any potential pathway via testosterone in men, we conducted a randomized, double-blind, placebo-controlled, parallel trial in Hong Kong. In total, 84 eligible Chinese men with hyperlipidemia were randomized to berberine (500 mg orally, twice a day) or placebo for 12 weeks. CVD risk factors (lipids, thromboxane A2, blood pressure, body mass index and waist-hip ratio) and testosterone were assessed at baseline, and 8 and 12 weeks after intervention. We compared changes in CVD risk factors and testosterone after 12 weeks of intervention using analysis of variance, and after 8 and 12 weeks using generalized estimating equations (GEE). Of the 84 men randomized, 80 men completed the trial. Men randomized to berberine had larger reductions in total cholesterol (-0.39 mmol/L, 95% confidence interval (CI) -0.70 to -0.08) and high-density lipoprotein cholesterol (-0.07 mmol/L, 95% CI -0.13 to -0.01) after 12 weeks. Considering changes after 8 and 12 weeks together, berberine lowered total cholesterol and possibly low-density lipoprotein-cholesterol (LDL-c), and possibly increased testosterone. Changes in triglycerides, thromboxane A2, blood pressure, body mass index and waist-hip ratio after the intervention did not differ between the berberine and placebo groups. No serious adverse event was reported. Berberine is a promising treatment for lowering cholesterol. Berberine did not lower testosterone but instead may increase testosterone in men, suggesting sex-specific effects of berberine. Exploring other pathways and assessing sex differences would be worthwhile, with relevance to drug repositioning and healthcare.

The effect of liver enzymes on body composition: A Mendelian randomization study.

BACKGROUND: Higher alanine transaminase (ALT), indicating poor liver function, is positively associated with diabetes but inversely associated with body mass index (BMI) in Mendelian randomization (MR) studies, suggesting liver function affects muscle mass. To clarify, we assessed the associations of liver enzymes with muscle and fat mass observationally with two-sample MR as a validation. METHODS: In the population-representative "Children of 1997" birth cohort (n = 3,455), we used multivariable linear regression to assess the adjusted associations of ALT and alkaline phosphatase (ALP) at ~17.5 years with muscle mass and body fat percentage observationally. Genetic variants predicting ALT, ALP and gamma glutamyltransferase (GGT) were applied to fat-free and fat mass in the UK Biobank (n = ~331,000) to obtain unconfounded MR estimates. RESULTS: Observationally, ALT was positively associated with muscle mass (0.11 kg per IU/L, 95% confidence interval (CI) 0.10 to 0.12) and fat percentage (0.15% per IU/L, 95% CI 0.13 to 0.17). ALP was inversely associated with muscle mass (-0.03 kg per IU/L, 95% CI -0.04 to -0.02) and fat percentage (-0.02% per IU/L, 95% CI -0.03 to -0.01). Using MR, ALT was inversely associated with fat-free mass (-0.41 kg per 100% in concentration, 95% CI -0.64 to -0.19) and fat mass (-0.58 kg per 100% in concentration, 95% CI -0.85 to -0.30). ALP and GGT were unclearly associated with fat-free mass or fat mass. CONCLUSION: ALT reducing fat-free mass provides a possible pathway for the positive association of ALT with diabetes and suggests a potential target of intervention.

Birth weight and prematurity with lung function at ~17.5 years: "Children of 1997" birth cohort.

We aimed to determine if prematurity and lower birth weight are associated with poorer lung function in a non-western developed setting with less marked confounding by socioeconomic position. Using multivariable linear regression in Hong Kong's "Children of 1997" birth cohort, adjusted associations of prematurity and birth weight with forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), and forced expiratory flow at 25-75% of the pulmonary volume (FEF25-75%) at ~17.5 years were assessed. Associations for birth weight were stronger in boys for FEV1 (boys: 0.31 L, 95% confidence interval (CI) 0.24 to 0.38, girls: 0.18 L, 95% CI 0.12 to 0.25), FVC (boys: 0.36 L, 95% CI 0.27 to 0.44, girls: 0.22 L, 95% CI 0.15 to 0.28) and FEF25-75% (boys: 0.35 L, 95% CI 0.21 to 0.49, girls: 0.22 L, 95% CI 0.09 to 0.34) adjusted for age, socioeconomic position and infant and maternal characteristics. Similarly adjusted, preterm birth (compared to full-term birth) was associated with lower FEV1/FVC and FEF25-75%. Thus, associations of lower birth weight, especially in boys, and prematurity with poorer lung function at 17.5 years were found. Identifying underlying mechanism might contribute to the improvement of pulmonary health and the prevention of adult respiratory illness.

The effect of liver enzymes on adiposity: a Mendelian randomization study.

Poorer liver function is positively associated with diabetes in Mendelian randomization (MR) studies. Observationally, adiposity is associated with poorer liver function. To clarify the etiology, we assessed the association of liver enzymes with adiposity observationally and using two-sample MR for validation. In the "Children of 1997" birth cohort, we used multivariable linear regression to assess the associations of alanine transaminase (ALT) and alkaline phosphatase (ALP) at ~17.5 years with body mass index (BMI) (n = 3,458). Using MR, genetic predictors of ALT, ALP and gamma glutamyltransferase (GGT), were applied to genome-wide association studies of BMI (n = 681,275), waist circumference (WC) (n = 224,459) and waist-hip ratio (WHR) (n = 224,459) to obtain unconfounded estimates. Observationally, ALT was positively associated with BMI (0.10 kg/m2 per IU/L, 95% confidence interval (CI) 0.09 to 0.11). ALP was inversely associated with BMI (-0.018 kg/m2 per IU/L, 95% CI -0.024 to -0.012). Using MR, ALT was inversely associated with BMI (-0.14 standard deviation per 100% change in concentration, 95% CI -0.20 to -0.07), but not WC or WHR. ALP and GGT were unrelated to adiposity. Poorer liver function might not cause adiposity; instead higher ALT might reduce BMI, raising the question as to the role of ALT in body composition.

Associations of growth from birth to puberty with glycemic indicators at ~17.5 years: Evidence from Hong Kong's "Children of 1997" birth cohort.

BACKGROUND: From an evolutionary biology perspective, where growth and reproduction trade-off against longevity, we assessed the associations of growth from birth to puberty by phase with later glycemic indicators and any differences by sex. METHODS: In the population-representative Hong Kong Chinese "Children of 1997" birth cohort (n = 8327), the relation of initial size (weight-for-age z score (WAZ) at birth, length/height-for-age z score (LAZ) at 3 months or body-mass-index-for-age z score (BAZ) at 3 months based on the World Health Organization growth standards/references) and growth at different phases (WAZ gains from 0 to 2 and 2 to 8 years, LAZ or BAZ gains from 3 months to 3 years, 3 to 8 years and 8 to 14 years) with fasting plasma glucose (FPG) and glycated hemoglobin (HbA1c) at ~17.5 years, was assessed using adjusted partial least squares regression. Additional analyses further considered growth in late and early infancy. RESULTS: This study included 3276 of the cohort participants. Higher WAZ gain from 2 to 8 years, LAZ and BAZ gains from 3 to 8 years were consistently associated with higher FPG, adjusted for maternal and infant characteristics, family history of diabetes and household income. Also, higher BAZ gain from 3 to 8 years was associated with higher HbA1c. These associations did not differ by sex. CONCLUSIONS: Our findings suggest different mechanisms could underlie the pathogenesis of glucose intolerance. Factors that drive specific growth at different phases need to be evaluated to better inform child growth management for long-term health outcomes.

Associations of growth from birth to puberty with blood pressure and lipid profile at ~17.5 years: evidence from Hong Kong's "Children of 1997" birth cohort.

The role of early growth in later health is controversial. We examined the associations of growth at different phases from birth to puberty with blood pressure and lipid profile at ~17.5 years. In the population-representative "Children of 1997" birth cohort, growth was measured as (i) weight-for-age z score (WAZ) at birth and WAZ gains from 0 to 2 and 2 to 8 years and (ii) body-mass-index-for-age z score (BAZ) and length/height-for-age z score (LAZ) at 3 months and BAZ and LAZ gains from 3 months to 3 years, 3 to 8 years and 8 to 14 years, based on the World Health Organization growth standards/references. Adjusted partial least squares regression was used to assess simultaneously the associations of growth with height-, age- and sex-specific systolic (SBPZ) and diastolic blood pressure z scores (DBPZ), low- (LDL) and high-density lipoprotein (HDL) and triglycerides (TG) at ~17.5 years. Among 3410 children, higher WAZ, BAZ and LAZ gains from initial size to 8 years were associated with higher SBPZ. Higher gains in WAZ and BAZ from 2 to 8 years were consistently associated with higher DBPZ, LDL and TG and lower HDL. Lower LAZ at 3 months and higher LAZ gain from 3 months to 3 years were associated with lower HDL and higher TG. Greater growth in weight, body mass index and length/height had negative associations with blood pressure and lipid profile at ~17.5 years, but the differences by growth measure, phase and outcome suggest a complex underlying process.

Sleep duration and risk of diabetes: Observational and Mendelian randomization studies.

Inadequate sleep could contribute to type 2 diabetes, but observational studies are inconsistent and open to biases, particularly from confounding. We used Mendelian randomization (MR) to obtain an unconfounded estimate of the effect of sleep duration on diabetes, fasting glucose (FG) and hemoglobin A1c (HbA1c), and an observation study to assess differences by sex. Using MR, we assessed the effects of genetically instrumented sleep on diabetes, based on 68 single nucleotide polymorphisms (SNPs), applied to the DIAbetes Genetics Replication and meta-analysis case (n = 26,676)-control (n = 132,532) study and on FG and HbA1c, based on 55 SNPs, applied to the Meta-Analyses of Glucose and Insulin-related traits Consortium (MAGIC) study of FG (n = 122,743) and HbA1c (n = 123,665). In the population-representative Hong Kong Chinese "Children of 1997" birth cohort we assessed whether associations of sleep duration at ~17.5 years with FG and HbA1c differed by sex. Using inverse variance weighting with multiplicative random effects, sleep duration was not associated with diabetes (odds ratio (OR) 0.85 per hour of sleep, 95% confidence interval (CI) 0.64 to 1.13), FG (-0.032 mmol/l per hour of sleep, 95% CI -0.126 to 0.063) or HbA1c (-0.022% per hour of sleep, 95% CI -0.069 to 0.024). In "Children of 1997", the associations of sleep duration with FG differed by sex (p for interaction 0.05) but not with HbA1c. Overall sleep duration does not appear to be related to diabetes, FG or HbA1c, but the possibility of sex differences merits investigation.

Birth weight, gestational age and late adolescent liver function using twin status as instrumental variable in a Hong Kong Chinese birth cohort: "Children of 1997".

Birth weight (BW) is inversely associated with diabetes and liver function in Mendelian Randomization studies. Observationally, lower BW is usually also associated with poorer liver function. However, these studies could be confounded by socioeconomic position. Here we assessed if BW is associated with liver function in a unique population with little socio-economic patterning of BW, using both instrumental variable and an observational analysis. We used instrumental variable analysis (IVA) to assess the association of BW with liver function (alanine transaminase (ALT), alkaline phosphatase (ALP), bilirubin, and albumin) at ~17 years with twin status as an instrumental variable in the prospective population-representative "Children of 1997" birth cohort (n = 8327). We also conducted an observational analysis adjusted for sex, maternal age, maternal migrant status, smoking and parental socio-economic position. A generalized linear model with gamma family was used for ALT, ALP, and bilirubin because they are not normally distributed. Using IVA, BW was not associated with ALT, ALP or bilirubin, but was possibly negatively associated with albumin (-1.12 g/L, 95% confidence interval (CI) -2.08 to -0.16). Observationally, BW was negatively associated with ALT (-1.23 IU/L, 95% CI -2.16 to -0.30), ALP (-1.72 IU/L, 95% CI -3.43 to -0.01) and higher albumin (-0.23 g/L, 95% CI -0.40 to -0.06). Poor liver function may be a pathway by which the risks of lower BW are actuated. This insight might help identify post-natal targets of intervention to mitigate the adverse health effects of lower birth weight.

Socioeconomic disparities in preterm birth and birth weight in a non-Western developed setting: evidence from Hong Kong's 'Children of 1997' birth cohort.

BACKGROUND: Preterm birth (PTB), low birth weight and small-for-gestational age (SGA) are associated with lower socioeconomic position (SEP) in developed Western settings, but it is unclear if such disparities persist to the same extent elsewhere, and whether associations differ by measure of SEP used. Here, we assessed the association of SEP with PTB, birth weight and SGA in the recently developed non-Western setting of Hong Kong where few women smoke or use alcohol. METHODS: We used multivariable logistic and linear regression to assess the associations of parental and neighbourhood SEP with PTB, birth weight and SGA among 8173 singleton births from the Hong Kong population-representative 'Children of 1997' birth cohort. RESULTS: The only measure of SEP associated with PTB was type of housing adjusted for maternal age (p for trend 0.046). Highest paternal education had a small positive association with birth weight adjusted for gestational age (21 g, 95% CI 0.2 to 43 g for ≥grade 12 compared with ≤grade 9), as did residing in private compared with public housing (21 g, 95% CI 3 to 39 g). However, these associations did not persist after adjusting for mother's age. Lower neighbourhood Gini coefficient adjusted for mother's age was associated with a lower risk of SGA (OR 0.78, 95% CI 0.63 to 0.98). None of these associations remained after adjusting for multiple comparisons. CONCLUSIONS: PTB, birth weight and SGA may be less clearly socially patterned in Hong Kong than other developed settings, highlighting the need for setting-specific interventions to prevent adverse birth outcomes.

Gestational Age, Birthweight for Gestational Age, and Childhood Hospitalisations for Asthma and Other Wheezing Disorders.

BACKGROUND: Preterm birth, early term birth, and low birthweight are associated with childhood wheezing disorders in developed Western settings, but observed associations could be confounded by socio-economic position. This study aims to clarify such associations in a developed non-Western setting with a different confounding structure. METHODS: Using Cox regression, we examined the adjusted associations of gestational age and birthweight for gestational age with time to first public hospital admission for asthma, bronchitis, and bronchiolitis (International Classification of Diseases, Ninth Version Clinical Modification 466, 490, and 493) from 9 days to 12 years in a population-representative birth cohort of 8327 Chinese children in Hong Kong, a developed setting with less clear social patterning of prematurity or birthweight. Analyses were adjusted for infant and parental characteristics and socio-economic position. RESULTS: Children born late preterm (34 to <37 weeks) had higher risk of hospitalisation for asthma and other wheezing disorders [hazard ratio (HR) 1.99, 95% confidence interval (CI) 1.48, 2.67] than children born full term (39 to <41 weeks). Early term births (37 to <39 weeks) had HR 1.01 (95% CI 0.84, 1.22), late term births (41 to <42 weeks) had HR 0.77 (95% 0.59, 1.01), and post-term births (≥42 weeks) had HR 0.56 (95% CI 0.32, 0.98). Large for gestational age was associated with lower risk of hospitalisation (HR 0.76, 95% CI 0.57, 0.99). CONCLUSION: The association of preterm birth with childhood wheezing could be biologically mediated. We cannot rule out an association for early term births.