Prospective study of gestational diabetes mellitus risk in relation to maternal recreational physical activity before and during pregnancy

Physical activity has been associated with a reduced risk of gestational diabetes mellitus, but inferences have been hampered by recall and selection bias. The authors examined the relation between recreational physical activity before and during pregnancy and risk of gestational diabetes mellitus in a prospective cohort study. In 1996-2000, 909 normotensive, nondiabetic women in Seattle and Tacoma, Washington, were questioned during early gestation about physical activity performed during the year before and 7 days prior to the interview during pregnancy. Compared with inactive women, women who participated in any physical activity during the year before experienced a 56% risk reduction (relative risk (RR) = 0.44, 95% confidence interval (CI): 0.21, 0.91). Women spending >/=4.2 hours/week engaged in physical activity experienced a 76% reduction in gestational diabetes mellitus risk (RR = 0.24, 95% CI: 0.10, 0.64), and those expending >/=21.1 metabolic equivalent-hours/week experienced a 74% reduction (RR = 0.26, 95% CI: 0.10, 0.65) compared with inactive women. Physical activity during pregnancy was also associated with reductions in gestational diabetes mellitus risk. Women who engaged in physical activity during both time periods experienced a 69% reduced risk (RR = 0.31, 95% CI: 0.12, 0.79). Findings suggest that efforts to increase maternal physical activity may contribute to substantial reductions in gestational diabetes mellitus risk.     

Perceived physical exertion during healthcare work and risk of chronic pain in different body regions: prospective cohort study

Purpose

To estimate the risk of developing chronic musculoskeletal pain in different body regions from varying degrees of perceived physical exertion during healthcare work.

Methods

Prospective cohort study among 4,977 Danish female healthcare workers responding to a baseline and follow-up questionnaire in 2005 and 2006, respectively. Using multi-adjusted logistic regression analysis, the risk of developing chronic pain (>30 days last year) at follow-up in the low back, neck/shoulder, and knees—among those without pain (0 days last year) in these respective body regions at baseline—from moderate and strenuous (reference: light) perceived physical exertion during healthcare work was modeled.

Results

Adjusted for age, BMI, tenure, smoking status, and leisure physical activity, strenuous perceived physical exertion during healthcare work increased the risk of chronic low back pain (OR 3.16, 95 % CI 1.79–5.57) and chronic knee pain (OR 1.87, 95 % CI 1.19–2.94) at follow-up among those without pain in these respective body regions at baseline. With additional adjustment for psychosocial work conditions, only the risk of developing chronic low back pain from strenuous physical exertion remained significant (OR 1.99, 95 % CI 1.02–3.88). Strenuous physical exertion was not a risk factor for chronic neck pain, and moderate physical exertion was not a risk factor for chronic pain in any of the body regions.

Conclusion

Strenuous perceived physical exertion during healthcare work is a risk factor especially for developing chronic pain in the low back. The possible preventive effect of reducing strenuous physical exertion should be tested in randomized controlled trials.     

Physical Activity and Health-Related Quality of Life During Pregnancy: A Secondary Analysis of a Cluster-Randomised Trial

The aim of the study was to evaluate the role of physical activity before and during pregnancy on health-related quality of life (HRQoL). Data from the cluster-randomised gestational diabetes mellitus primary prevention trial conducted in maternity clinics were utilised in a secondary analysis. The cases considered were pregnant women who reported engaging in at least 150 min of moderate-intensity leisure-time physical activity per week (active women) (N = 80), and the controls were women below these recommendations (less active) (N = 258). All participants had at least one risk factor for gestational diabetes mellitus. Their HRQoL was evaluated via the validated generic instrument 15D, with HRQoL at the end of pregnancy examined in relation to changes in physical activity during pregnancy. Logistic regression models addressed age, parity, education, and pre-pregnancy body mass index. At the end of pregnancy, the expected HRQoL was higher (tobit regression coefficient 0.022, 95 % CI 0.003–0.042) among active women than less active women. Active women also had greater mobility (OR 1.98, 95 % CI 1.04–3.78), ability to handle their usual activities (OR 2.22, 95 % CI 1.29–3.81), and vitality (OR 2.08, 95 % CI 1.22–3.54) than did less active women. Active women reported higher-quality sleep (OR 2.11, 95 % CI 1.03–4.30) throughout pregnancy as compared to less active women. Meeting of the physical activity guidelines before pregnancy was associated with better overall HRQoL and components thereof related to physical activity.     

The Association Between Physical Activity and Maternal and Neonatal Outcomes: A Prospective Cohort

Some evidence, but not enough to be conclusive, suggests that physical activity in pregnancy reduces the risk of perinatal complications. Our objective was to examine if physical activity in the year before pregnancy and in the first half of pregnancy is associated with maternal and neonatal outcomes. Associations between physical activity and maternal and neonatal outcomes were examined in a prospective cohort (n = 1,749) in Halifax, Canada. The Kaiser Physical Activity Survey, completed at approximately 20 weeks’ gestation, requested information regarding physical activity during the year before the pregnancy and the first 20 weeks of pregnancy. Outcomes were assessed by medical chart review. Multiple logistic regression was used to estimate odds ratios (OR) with 95 % confidence intervals (CI). Women with prepregnancy physical activity levels in the middle and highest tertiles were more likely to have high gestational weight gain relative to women in the lowest tertile [OR (CI): 1.40 (1.06–1.85) and 1.57 (1.18–2.09), respectively]. Higher physical activity in the first half of pregnancy decreased the odds of delivering a macrosomic infant (p trend = 0.005). Associations were not observed between total physical activity and gestational diabetes, gestational hypertension, pre-eclampsia, preterm birth, and low birth weight. Physical activity before, but not in the first half of pregnancy, is associated with high gestational weight gain. Physical activity in the first half of pregnancy may reduce the occurrence of macrosomia without affecting preterm birth or low birth weight.     

A Prospective Study of the Association Between Vigorous Physical Activity During Pregnancy and Length of Gestation and Birthweight

Current US pregnancy-related physical activity recommendations do not provide specific guidance for vigorous intensity activity. We examined the associations between vigorous physical activity during pregnancy and length of gestation and birthweight. Methods: Women were recruited before 10?weeks gestation. At 13?C16?weeks gestation, participants reported the type, frequency, and duration of their typical weekly vigorous physical activities. Activity domains included recreational, occupational, household, and child/adult care. Infant birth date was obtained from medical or vital records; if unavailable, self-report was used. Birthweight (from vital records) was studied among term births. We analyzed gestational age among 1,647 births using discrete-time survival analysis. We used logistic and linear regression to analyze preterm birth (birth at <37?weeks) and birthweight, respectively. Vigorous recreational activity was associated with longer gestation (any vs. none, hazard ratio (HR) [95% CI]: 0.85 [0.70, 1.05]) and we did not detect any dose?Cresponse association. Higher frequency of vigorous recreational activity sessions (adjusted for total volume of activity) was associated with a decreased odds of preterm birth (??4 sessions/week vs. 0 or 1, OR [95% CI]: 0.08 (0.006, 1.0). Birthweight was not associated with physical activity measures. In summary, vigorous physical activity does not appear to be detrimental to the timing of birth or birthweight. Our data support a reduced risk of preterm birth with vigorous recreational activity, particularly with increased frequency of recreational activity sessions. Future studies should investigate the components of physical activity (i.e., intensity, duration, and frequency) in relation to birth outcomes.     

The Association Between Gestational Diabetes Mellitus and Recreational Physical Activity

We aimed to investigate the association of recreational physical activity before pregnancy with gestational diabetes mellitus (GDM). A cross-sectional study was performed using self-reported data from the Pregnancy Risk Assessment and Monitoring System. The study population included 1,052 self-reported GDM cases and 10,351 non-GDM controls. Recreational physical activity in the 3 months before pregnancy was recalled in postpartum structured interviews. Compared to women exercising less than 1 day per week, women who exercised >5 days per week in the 3 months before pregnancy had a 31% lower odds of GDM (adjusted odds ratio [aOR]: 0.69; 95% confidence interval [CI]: 0.46, 1.03). Women who exercised 1–4 days per week had a 7% lower odds of GDM (aOR: 0.93; 95%CI: 0.72, 1.19). We did not observe statistically significant associations between pre-pregnancy physical activity and GDM risk. However, the magnitude and direction of association are consistent with previous observational studies. These studies collectively suggest a role of physical activity in GDM prevention.     

Psychosocial and physical work environment, and risk of pelvic pain in pregnancy. A study within the Danish national birth cohort

OBJECTIVE: The sparse knowledge of the aetiology of pelvic pain in pregnancy makes evidence based prevention a limited option. The aim of this study was to examine the relation between pelvic pain in pregnancy and physical and psychosocial working conditions. METHODS: This study used self reported data on working conditions for 1219 cases and 1539 controls, sampled as a nested case-control study within the Danish national birth cohort. Cases and controls were selected on the basis of self reported pelvic pain intensity, pain localisation, and pain impact on daily living activities. Exposure data were collected prospectively; early in pregnancy and before the onset of pelvic pain. Main outcome measures were odds ratios for pelvic pain in pregnancy as a function of physical and psychosocial working conditions. RESULTS: Pregnant women with fixed evening work and with rotating shifts (without night shift) had odds ratios for pelvic pain in pregnancy of 1.76 (95% confidence intervals 1.04 to 2.96) and 1.65 (1.22 to 2.24), respectively, compared with women with day work. Physically strenuous work was associated with an almost 50% increased risk of pelvic pain in pregnancy (1.47; 1.17 to 1.84). In women who were under high psychosocial strain at work odds ratio was 1.39 (1.12 to 1.74) compared with women with low job strain. CONCLUSION: Both physically and psychosocially demanding working conditions, measured by physically strenuous work, rotating shifts, and high job strain, are associated with an increased reporting of pelvic pain in pregnancy.     

Case-control study of lifetime physical activity and breast cancer risk

A population-based case-control study of 1,233 incident breast cancer cases and 1,237 controls was conducted in Alberta, Canada, in 1995-1997 to examine the effect of lifetime physical activity patterns on breast cancer risk. No associations between physical activity and breast cancer were found for premenopausal women. For postmenopausal women in the highest quartile (> or =161 metabolic equivalent (MET)-hours/week per year) versus the lowest quartile (<104.8 MET-hours/week per year) of lifetime total physical activity, the adjusted odds ratio was 0.70 (95% confidence interval (CI): 0.52, 0.94). When the risks associated with each type of activity were examined for postmenopausal women, household and occupational activity conferred the largest risk reductions (odds ratio (OR) = 0.57, 95% CI: 0.41, 0.79 and OR = 0.59, 95% CI: 0.44, 0.81, respectively, for highest vs. lowest quartiles of activity), while recreational activity was not associated with any risk reductions. For postmenopausal women, the authors found stronger risk reductions for those who were also nonsmokers (OR = 0.64, 95% CI: 0.46, 0.88), non-alcohol-drinkers (OR = 0.39, 95% CI: 0.11, 0.77), or nulliparous (OR = 0.22, 95% CI: 0.07, 0.70) when they compared the highest with the lowest quartile of lifetime total physical activity. This study provides evidence that lifetime total activity reduces risk of postmenopausal breast cancer.     

Previous physical activity decreases the risk of low back pain and pelvic pain during pregnancy

AIMS: The aim of the study was to investigate physical activity prior to pregnancy, occupation, and treatment in women with low back pain and pelvic pain (LBPP) during pregnancy. METHODS: All women who gave birth at two hospitals in northern Sweden from 1 January 2002 to 30 April 2002 were invited to complete a questionnaire on their obstetric and gynaecological history, actual pregnancy, and delivery. The sample was analysed with calculation of odds ratios (OR) and their 95% confidence intervals (CI). Cox regression analyses were performed. Women with LBPP reporting a pain maximum of 7 or more on a visual analogue scale (0-10 cm) were considered to have "high pain score LBPP" (hps-LBPP). RESULTS: The response rate was 83% (n = 891). A higher number of years of regular leisure physical activity (RLPA) decreased the risk of LBPP during pregnancy. The risk of hps-LBPP was increased for women who characterized their occupation as "mainly active" (OR = 2.0, 95% CI: 1.1-3.5) and "physically demanding" (OR = 1.9, 95% CI: 1.1-3.2). Visiting a physician as a result of LBPP was reported by 46.2%, and the mean number of visits was 2.0. One-third of women with LBPP had received treatment, as had half of women with hps-LBPP. CONCLUSIONS: A higher number of years of previous RLPA decreases the risk of LBPP during pregnancy. Occupations described as "mainly active" and "physically demanding" are associated with increased risk of hps-LBPP during pregnancy.     

妊娠期糖尿病影响因素的病例对照研究

目的:探讨妊娠期糖尿病(GDM)发病的影响因素,为预防和治疗GDM的发生和发展提供理论依据。方法:采用回顾性分析的方法,将2007年9月～2008年9月在沈阳市盛京医院住院的129例GDM孕产妇与129例正常孕产妇(均为初产妇、单胎妊娠、汉族)按1∶1的比例进行病例对照研究。结果:单因素分析结果显示,孕产妇怀孕年龄、孕前体重指数(BMI)、孕后期体重、文化程度、早起时间、晚睡时间、孕前口味、孕前常饮饮料、怀孕胎次、糖尿病(DM)家族史、高血压家族史、孕前高脂血症、孕前运动、流产史在两组间的差异均有统计学意义。经过Logistic回归分析,有5项因素进入回归模型即怀孕年龄、孕前BMI、DM家族史和孕前口味为危险因素(P=0.000,OR=1.861,95%C.I为1.795～1.932,P=0.000,OR=2.750,95%C.I为1.660～2.852,P=0.000,OR=8.690,95%C.I为3.588～21.046,P=0.000,OR=1.615,95%C.I为1.503～3.750);文化程度为保护因素(P=0.002,OR=0.910,95%C.I为0.259～0.898)。结论:孕产妇怀孕年龄、孕前BMI、DM家族史、孕前高盐和高热量的饮食习惯可能是GDM的危险因素,文化程度是GDM的保护因素。     

妊娠期糖代谢异常的危险因素研究

目的探讨妊娠期糖代谢异常的危险因素。方法采用病例-对照研究方法,以2005年1-9月在某医院确诊的妊娠期糖代谢异常的100例孕产妇为病例组,以该院产前保健和分娩的糖代谢正常、孕周相同的200例孕产妇为对照组。对其一般情况、妊娠情况和相关健康行为等情况进行调查。采用多因素logistic回归分析方法分析与妊娠期糖代谢异常相关的因素。结果多因素logistic回归分析显示:孕妇年龄为26～30岁(OR=2.69,95%CI为1.29～5.56)和高于30岁(OR=4.58,95%CI为1.92～10.92)、经济收入超过3 000元(OR=7.17,95%CI为2.49～20.64)、容易激动(OR=1.88,95%CI为1.00～3.51)、食肉多(OR=4.91,95%CI为1.94～12.43)、参加体育锻炼每周1～3次(OR=0.35,95%CI为0.16～0.76)和4次以上(OR=0.32,95%CI为0.10～0.98)等因素与妊娠期糖代谢异常的关系密切。结论妊娠期糖代谢异常的主要危险因素为年龄大、经济收入高、容易激动和食大量肉,而适度体育锻炼为保护性因素。     

Case-control study of lifetime total physical activity and prostate cancer risk

A population-based case-control study of physical activity and prostate cancer risk was conducted in Alberta, Canada, between 1997 and 2000. A total of 988 incident, histologically confirmed cases of stage T2 or greater prostate cancer were frequency matched to 1,063 population controls. The Lifetime Total Physical Activity Questionnaire was used to measure occupational, household, and recreational activity levels from childhood until diagnosis. Multivariable logistic regression analyses were conducted. No association for total lifetime physical activity and prostate cancer risk was found (odds ratio (OR) for > or =203 vs. <115 metabolic equivalent-hours/week/year=0.87, 95% confidence interval (CI): 0.65, 1.17). By type of activity, the risks were decreased for occupational (OR=0.90, 95% CI: 0.66, 1.22) and recreational (OR=0.80, 95% CI: 0.61, 1.05) activity but were increased for household (OR=1.36, 95% CI: 1.05, 1.76) activity when comparing the highest and lowest quartiles. For activity performed at different age periods throughout life, activity done during the first 18 years of life (OR=0.78, 95% CI: 0.59, 1.04) decreased risk. When activity was examined by intensity of activity (i.e., low, <3; moderate, 3-6; and vigorous, >6 metabolic equivalents), vigorous activity decreased prostate cancer risk (OR=0.70, 95% CI: 0.54, 0.92). This study provides inconsistent evidence for the association between physical activity and prostate cancer risk.     

Perceived risk of chlamydial and gonococcal infection among sexually experienced young adults in the United States

CONTEXT: Understanding young adults' perceived risk of chlamydial and gonococcal infection can inform interventions to reduce the prevalence of these sexually transmitted diseases. METHODS: Bivariate and multivariate analyses, using data from Wave 3 of the National Longitudinal Study of Adolescent Health (2001-2002), were conducted to examine relationships between perceived risk and selected characteristics in two groups: a nationally representative sample of sexually experienced 18-26-year-olds and a subsample of those who tested positive for chlamydia or gonorrhea. The relationship between current infection and perceived risk was also evaluated. RESULTS: Only 14% of all respondents and 33% of infected participants reported some perceived risk of chlamydial or gonococcal infection. In the overall sample, the odds of perceiving risk were significantly elevated among blacks, Hispanics, unmarried respondents, inconsistent condom users and nonusers, respondents who reported multiple partners in the past year, those who had received a diagnosis of chlamydia or gonorrhea in the past year, and those reporting current symptoms (odds ratios, 1.5-3.3). Currently infected participants were significantly more likely than those who were not infected to perceive some risk of infection (2.4). Among infected respondents, the factors positively associated with perceived risk were being black or Hispanic, using condoms inconsistently or not using them, having exchanged money for sex, having been tested in the past year but with no diagnosis, having received a diagnosis, and reporting current symptoms (2.5-5.2). CONCLUSIONS: Interventions to increase the accuracy of young adults' risk perceptions may influence sexual and health care-seeking behaviors in a way that will reduce rates of chlamydia and gonorrhea.     

Association between gestational diabetes and pregnancy-induced hypertension

Gestational diabetes and pregnancy-induced hypertension are common, and their relation is not well understood. The authors conducted a population-based case-control study using 1992-1998 Washington State birth certificate and hospital discharge records to investigate this relation. Consecutive cases of pregnancy-induced hypertension were divided into four groups based on International Classification of Diseases, Ninth Revision codes: eclampsia (n=154), severe preeclampsia (n=1,180), mild preeclampsia (n=5,468), and gestational hypertension (n=8,943). Cases were compared with controls who did not have pregnancy-induced hypertension (n=47,237). Gestational diabetes was more common in each case group (3.9% in eclamptics, 4.5% in severe preeclamptics, and 4.4% in both mild preeclamptics and those with gestational hypertension) than in controls (2.7%). After adjustment for body mass index, age, ethnicity, parity, and prenatal care, gestational diabetes was associated with increased risk of severe preeclampsia (odds ratio (OR)=1.5, 95% confidence interval (CI): 1.1, 2.1), mild preeclampsia (OR=1.5, 95% CI: 1.3, 1.8), and gestational hypertension (OR=1.4, 95% CI: 1.2, 1.6). Gestational diabetes was more strongly associated with pregnancy-induced hypertension among women who received less prenatal care (OR=4.2 for eclampsia and OR=3.1 for severe preeclampsia, p<0.05 for both) and among Black women (OR for eclampsia and preeclampsia together=3.9, p<0.05).     

The effect of leisure time physical activity on the risk of pre-eclampsia and gestational hypertension.

STUDY OBJECTIVE: To assess the relation between leisure time physical activity (LTPA) during the first 20 weeks of pregnancy and the risk of developing pre-eclampsia and gestational hypertension. DESIGN: Case-control study carried out over a 28 month period with retrospective data collection. SETTING: Six hospitals in Quebec City and four hospitals in Montreal. PARTICIPANTS: 172 women with pre-eclampsia, 254 with gestational diabetes, 505 controls. All were primiparous, with no history of high blood pressure before pregnancy (unless due to oral contraceptive use), or during the first 20 weeks of gestation. Cases were defined using recognised criteria, and 97% of those eligible agreed to be interviewed. Controls delivered in same hospital immediately after cases and had no more than one reading of elevated blood pressure during pregnancy; 96% of those eligible agreed to be interviewed. MEASUREMENTS AND MAIN RESULTS: Participants were interviewed in hospital a few days after delivery using a questionnaire. Information was collected on type, frequency and average duration of any LTPA performed regularly during the first 20 weeks of pregnancy, together with medical, obstetric and sociodemographic details. It was found that women who performed regular LTPA had a reduced risk of pre-eclampsia (adjusted RR 0.67, 95% CI 0.46-0.96) and gestational hypertension (aRR 0.75, 95% CI 0.54-1.05), and the relative risks decreased as the average time spent in LTPA increased (aRR for pre-eclampsia among women with low, moderate and high energy expenditure: 1.00, 0.77 and 0.57, p = 0.01). The same trend was present for gestational hypertension (1.00, 0.80 and 0.71, respectively, p = 0.08). CONCLUSIONS: Leisure time physical activity during the first half of pregnancy is likely to reduce the risk of pre-eclampsia and gestational hypertension.     

Physical activity and hip fracture: a population-based case-control study. Swedish Hip Fracture Study Group

BACKGROUND: A growing body of literature suggests that physical activity may be a protective factor against hip fracture. METHODS: To study the association between hip fracture risk and recreational physical activity at various ages, changes in activity during adult life, occupational physical activity and how risks vary by adult weight change, we performed a population-based case-control study among postmenopausal women aged 50-81 years residing in six counties in Sweden in 1993-1995. The analysis consisted of 1327 women with hip fracture and 3262 randomly selected controls. Information on leisure physical activity before age 18, at 18-30 years and during recent years was based on a questionnaire. Data on occupational physical activity were collected through an independent classification of job titles obtained from record linkage with census data from 1960, 1970 and 1980. RESULTS: There was a protective effect of recent leisure physical activity. Compared to women who reported no leisure activity, the odds ratios (OR) were 0.79 (95% CI: 0.62-1.00), 0.67 (95% CI: 0.54-0.84) and 0.48 (95% CI: 0.39-0.60) for women who exercised <1 h per week, 1-2 h per week, and 3+ h per week, respectively. These decreased OR were more pronounced in women who had lost weight after 18 years of age than in those who had gained weight. Women with high physical activity at both 18-30 years and during recent years did not have a stronger protection than those with isolated high activity late in life, after accounting for recent activity. Occupational physical activity was not associated with hip fracture risk in this study. CONCLUSIONS: Recent physical activity is protective against hip fracture. The protective effect is most pronounced in women who had lost weight after age 18.     

Recreational physical activity and the risk of preeclampsia: a prospective cohort of Norwegian women

Previous case-control studies suggest that recreational physical activity protects against preeclampsia. Using a prospective design, the authors estimated the risk of preeclampsia for pregnant women according to level of physical activity, taking other variables that influence risk into consideration. The data set comprised 59,573 pregnancies from the Norwegian Mother and Child Cohort Study (1999-2006). Information on physical activity and other exposures was extracted from questionnaire responses given in pregnancy weeks 14-22, whereas diagnosis of preeclampsia was retrieved from the Medical Birth Registry of Norway. Estimation and confounder control was performed with multiple logistic regression. About 24% of pregnant women reported no physical activity, and 7% reported more than 25 such activities per month. The adjusted odds ratio was 0.79 (95% confidence interval: 0.65, 0.96) for preeclampsia when comparing women who exercised 25 times or more per month with inactive women. The association appeared strongest among women whose body mass index was less than 25 kg/m(2) and was absent among women whose body mass index was higher than 30 kg/m(2). These results suggest that the preventive effect of recreational physical activity during pregnancy may be more limited than has been shown in case-control studies and may apply to nonobese women only.     

新冠肺炎疫情期间广东省小学生视屏行为现状及影响因素

  目的  了解新型冠状肺炎疫情期间广东省小学生网课及视屏行为现状及其影响因素,为儿童视屏行为干预和健康促进提供依据。  方法  采用方便抽样的方法抽取广东省广州市、湛江市、中山市共5 266名6~12岁小学生家长进行线上问卷调查。采用方差分析或χ2检验比较各年级学生网课和视屏行为现状的差异,采用多因素Logistic回归分析娱乐型视屏时间过长的影响因素。  结果  小学生学习日和周末娱乐型视屏时间过长检出率分别为42.2%和55.2%;与非疫情的学期相比,娱乐型视屏时间在学习日和周末分别增长了40.31和33.07 min/d。各年级小学生平均单节网课时长为(26.07±9.62)min,单日网课时长为(110.41±51.98)min。性别、年级、是否独生子女、父母文化程度等人口学因素是娱乐型视屏时间过长的影响因素; 与父母陪伴运动锻炼频率较高的儿童相比,父母陪伴运动锻炼频率中等(学习日: OR=1.27,周末: OR=1.40)和较低(学习日: OR=1.86,周末: OR=1.84)儿童娱乐型视屏时间过长的风险较高(P值均 < 0.05);相较于父母限制视屏行为频率较高的儿童,父母限制视屏行为频率中等和较低儿童学习日娱乐型视屏时间过长的风险较高(OR值分别为1.61,1.32,P值均 < 0.05);父母娱乐型视屏时间≥2 h/d较 < 2 h/d易使儿童娱乐型视屏时间过长的风险增加(学习日: OR=3.09,周末: OR=2.81,P值均 < 0.05);儿童中高强度体力活动 < 1 h/d(学习日: OR=1.31)相较于≥1 h/d,用电子设备学习时间1~2 h/d(学习日: OR=2.65,周末: OR=2.65)、≥2 h/d(学习日: OR=4.05,周末: OR=5.24)相较于 < 1 h/d也增加了娱乐型视屏时间过长的风险(P值均 < 0.05)。  结论  疫情期间,广东省儿童视屏时间水平较高,需加强恢复学校教学秩序后儿童的行为监测以及实施有针对性的干预措施。     

体力活动与女性乳腺癌发病关系的病例对照研究

目的 探讨体力活动与乳腺癌发病的关系。方法 采用以医院为基础的病例对照研究,调查某大学2所附属医院2012年4月~2014年12月间确诊的25～70岁549例乳腺癌患者和同期同医院就诊的549例非肿瘤患者的体力活动情况和相关危险因素。采用非条件Logistic回归模型分析体力活动与乳腺癌发病的关系。结果 校正各种混杂因素后,非职业性体力活动与乳腺癌发病风险降低有关（OR=0.69,95% CI:0.48～1.00）;与不参加体育活动者相比,参加体育活动对乳腺癌发病有保护作用（OR=0.61,95% CI:0.43～0.87）;与久坐不动的职业相比,轻度职业活动对乳腺癌发病有保护作用（OR=0.67,95% CI:0.47～0.97）,而家务活动与乳腺癌发病风险无关。不同雌激素受体（estrogen receptor,ER）和孕激素受体（progesterone receptor,PR）状态的亚组分析中,非职业性体力活动与ER+/PR+乳腺癌的发病风险降低有关。结论 非职业性体力活动、体育活动和轻度职业活动对女性乳腺癌有保护作用。     

Population-based study on occupational risk factors for preeclampsia and gestational hypertension

OBJECTIVES: Preeclampsia is a leading cause of maternal and perinatal morbidity. Work-related factors may influence the occurrence of this disorder. This case-control study estimated the associations between work-related physical and psychosocial factors and the risk of preeclampsia and gestational hypertension. METHODS: The eligible women consisted of a random sample of the women who delivered a singleton live birth in 1997-1999 in six regions of Quebec and worked during pregnancy. Cases of preeclampsia (N=102) and gestational hypertension (N=99) were compared with normotensive controls (N=4381). Information on occupational exposures at the onset of pregnancy was collected during phone interviews a few weeks after delivery. Detailed information was obtained on work schedule, postures, physical exertion, work organization, noise, vibration, and extreme temperature. Adjusted odds ratios (aOR) were estimated through polytomous logistic regression. RESULTS: Women standing daily at least 1 hour consecutively without walking experienced a higher risk of preeclampsia [aOR 2.5, 95% confidence interval (95% CI) 1.4-4.6], as well as women climbing stairs frequently (aOR 2.3, 95% CI 1.2-4.1) and women working more than 5 consecutive days without a day-off (aOR 3.0, 95% CI 1.0-9.5). Squatting or kneeling, pushing or pulling objects, whole-body vibration, forced pace, job strain, and no control on breaks were positively, but nonsignificantly, associated with preeclampsia. The associations were weaker for gestational hypertension. CONCLUSIONS: These findings suggest that being exposed to physically demanding and stressful occupational conditions at the onset of pregnancy increases the risk of preeclampsia.