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.     

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。     

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.     

Lifetime total physical activity and prostate cancer risk: a population-based case–control study in Sweden

The etiologic role of physical activity in prostate cancer development is unclear. We assessed the association between lifetime total physical activity and prostate cancer risk in a Swedish population-based case–control study comprising 1,449 incident prostate cancer cases and 1,118 unaffected population controls. Information regarding physical activity was obtained via a self-administered questionnaire assessing occupational, household, and recreational activity separately at various ages throughout an individual’s lifetime. Clinical data (TNM-classification, Gleason sum and PSA) was obtained from linkage to the National Prostate Cancer Registry. Overall, we observed no association between lifetime total physical activity and prostate cancer risk (odds ratio [OR] = 1.04, 95% confidence interval [CI] = 0.77–1.41 for ≥49.7 vs. <41.9 metabolic equivalent-hours per day). There was a significantly increased risk of prostate cancer in the most active men compared with the least active men in household (OR = 1.44, 95% CI = 1.08–1.92) and recreational physical activity (OR = 1.56, 95% CI = 1.16–2.10). Comparing the most active with the least active men, total physical activity was not associated with either localized disease (OR = 0.95, 95% CI = 0.67–1.34) or advanced disease (OR = 1.19, 95% CI = 0.83–1.71). These findings do not support the hypothesis that physical activity uniformly protects against prostate cancer development.     

Physical activity on the job and cancer in Missouri.

We conducted a series of case-control studies to investigate the risks of 16 cancer types in relation to occupational physical activity. These studies were based on Missouri Cancer Registry data for 17,147 White male cancer patients registered between 1984 and 1989. Colon cancer risk was increased for both the moderate (odds ratio (OR) = 1.1; 95% confidence interval (CI) = 1.0, 1.3) and low (OR = 1.2; 95% CI = 1.0, 1.5) activity levels. Similar elevations were observed for prostate cancer at the moderate (OR = 1.1; 95% CI = 1.0, 1.3) and low (OR = 1.5; 95% CI = 1.2, 1.8) levels of activity, and for cancer of the testis at the low activity level (OR = 2.2; 95% CI = 1.3, 3.7). An opposite trend (p less than 0.01) was noted for lung cancer, which showed decreased risk at the moderate (OR = 0.9; 95% CI = 0.8, 1.0) and low (OR = 0.8; 95% CI = 0.6, 0.9) activity levels. These associations suggest that further study of the relationship between physical activity and site-specific cancer risk is warranted.     

Adulthood lifetime physical activity and breast cancer

BACKGROUND: Epidemiologic studies have shown that breast cancer risk is reduced 30% to 40% in highly physically active compared with inactive women. However, the effects of moderate activities, timing of activities, and intervening effects of other risk factors remain less clear. METHODS: We analyzed data on physical activity patterns in 2176 incident breast cancer cases and 2326 controls in a population-based breast cancer case-control study in Poland conducted in 2000-2003. Using unconditional logistic regression analyses, we calculated odds ratios (ORs) and 95% confidence intervals (CIs) associated with physical activity levels (measured by average metabolic equivalents of energy expenditure hours per week), controlling for potential confounders. RESULTS: Total adult lifetime activity reduced risk of breast cancer, with individuals in the highest quartile having an OR of 0.80 (CI = 0.67-0.96) compared with the lowest quartile. Reduced risks were most consistent for the highest quartiles of moderate-to-vigorous activities: moderate/vigorous recreational activities (OR = 0.74; CI = 0.62-0.89), outdoor activities (0.81; 0.68-0.97), heavy physical work (0.60; 0.42-0.87), and combined high intensity (metabolic equivalent >6.0) activities (0.75; 0.63-0.90). These relations were not modified by body mass index, menopausal status, or family history of breast cancer. Reductions in risk with moderate/vigorous recreational activities were stronger for larger tumors and those with nodal involvement. Women who increased their recreational activity in their 50s had significantly reduced risk, with those in the highest tertile of change being at a 27% lower risk. CONCLUSIONS: Leisure-time moderate-to-vigorous activities reduce breast cancer risk irrespective of underlying host characteristics.     

Physical activity patterns in a diverse population of women

BACKGROUND: Demographic and psychosocial correlates of activity in domains other than recreational activity have not been well characterized and may be particularly relevant for health promotion efforts aimed at women. METHODS: Cross-sectional relationships between recreational, occupational, and household/caregiving physical activity and demographic and psychosocial factors were assessed with a mail survey in a random sample of 2,636 ethnically diverse women members of a large health maintenance organization, ages 20-65. Activity was assessed with a modified Baecke questionnaire that uses categorical responses regarding frequency of domain-specific activities to create four semicontinuous activity indices (sports/exercise, active living, occupational, household/caregiving). RESULTS: Multivariable logistic regression analysis showed that the likelihood of being in the highest quartile of the sports/exercise and active-living indices, compared with the other three quartiles, was decreased among older, nonwhite, less well educated, heavier women who had young children at home, lacked motivation to exercise, and perceived external obstacles to exercise behavior. The odds ratios (ORs) ranged from 0.38, 95% confidence interval (CI) 0.33-0.45, associated with low motivation, to 0.95, 95% CI 0.93-0.98, associated with increasing body mass index. Social support and confidence in one's ability to continue to exercise, even when faced with other pressures and demands (termed self-efficacy), were associated with increased likelihood of high levels of sports/exercise and active living (OR = 2.34, 95% CI 1. 83-2.98 and OR = 3.96, 95% CI 2.92-5.38, respectively). In contrast, the highest quartile of household/caregiving activity was positively associated with increasing age (OR = 1.28, 95% CI 1.16-1.42), Hispanic ethnicity (OR = 1.58, 95% CI 0.55-1.01), being married (OR = 1.70, 95% CI 1.33-2.18), having young children at home (OR = 6.99, 95% CI 4.33-11), and greater time constraints as a barrier to exercise (OR = 1.55, 95% CI 1.38-1.74) and was negatively associated with employment (OR = 0.38, 95% CI 0.30-0.47). Increased likelihood of the highest quartile of occupational activity was associated with high school education or less (OR = 2.26, 95% CI 1.74-2.94) and current smoking (OR = 1.66, 95% CI 1.23-2.23), while self-efficacy regarding exercise was associated with decreased likelihood (OR = 0. 77, 95% CI 0.61-0.96). CONCLUSIONS: These findings suggest that demographic and psychosocial correlates of physical activity vary by domain and that initiatives to promote physical activity in the population need to take these differences into account.     

Occupational risk factors for prostate cancer

BACKGROUND: Occupational risk factors for prostate cancer have been investigated with inconsistent findings. METHODS: This was a population-based case-control study of men in Northeastern Ontario, Canada. Cases (n = 760) were from the Ontario Cancer Registry, 50 to 84 years old, and diagnosed with prostate cancer between 1995 and 1998. Age-frequency matched controls (n = 1,632) were obtained from telephone listings. A questionnaire yielded information on occupational history and self-reported exposures to a list of occupational hazards. Exposures to these hazards were assessed by an occupational hygienist. RESULTS: An odds ratio estimate (OR) of 1.21 (95 percent confidence interval (% CI) 1.01, 1.46) was found for employment in trades, transport and equipment operators and related occupations, possibly related to exposure to whole-body vibration (OR = 1.38, 95% CI 1.07, 1.78). For the highest quartile of lifetime cumulative workplace physical activity an OR of 1.33 (95% CI 1.02, 1.74) was found. No statistically significant associations were found for any other occupational category or exposure. CONCLUSIONS: This study does not provide strong evidence for significant occupational risk factors for prostate cancer. However, whole-body vibration exposures, as well as physical activity, may be worth pursuing in future occupational studies.     

Physical activity and colorectal cancer

Physical activity has been inconsistently associated with rectal cancer despite the consistent association between physical activity and colon cancer. In this study, the authors evaluated the association between physical activity and rectal cancer using the same questionnaire used to evaluate the previously reported association with colon cancer. A population-based study of 952 incident cases of cancer in the rectum and rectosigmoid junction and 1,205 age- and sex-matched controls was conducted in Utah and northern California at the Kaiser Permanente Medical Care Program between 1997 and 2002. Vigorous physical activity was associated with reduced risk of rectal cancer in both men and women (odds ratio (OR) = 0.60, 95% confidence interval (CI): 0.44, 0.81 for men; OR = 0.59, 95% CI: 0.40, 0.86 for women). Among men, moderate levels of physical activity also were associated with reduced risk of rectal cancer (OR = 0.70, 95% CI: 0.51, 0.97). Participation in vigorous activity over the past 20 years conferred the greatest protection for both men and women (OR = 0.55, 95% CI: 0.39, 0.78 for men; OR = 0.44, 95% CI: 0.30, 0.67 for women). In summary, physical activity was associated with reduced risk of rectal cancer in these data. The reduced risk was similar to that previously observed for colon cancer.     

Physical activity and breast cancer risk among women in the southwestern United States

Physical activity may influence breast cancer risk through multiple mechanisms and at different periods in life. In this study we evaluate breast cancer risk associated with total and vigorous physical activity at ages 15, 30, and 50 years and the referent year prior to diagnosis/selection. Participants were non-Hispanic white (NHW) (1527 cases and 1601 control subjects) and Hispanic/American Indian (HAI) (798 cases and 924 controls) women. Both total and vigorous activity reduced risk of breast cancer in a dose-response manner. Among premenopausal women, only high total metabolic equivalent of the task (MET) hours of activity during the referent year was associated with reduced breast cancer risk in NHW women (odds ratio [OR] 0.62; 95% confidence interval [CI] 0.43, 0.91). Among postmenopausal women, physical activity had the greatest influence among women not recently exposed to hormones. Among these women, high total lifetime activity reduced risk of breast cancer for both NHW (OR 0.60; 95% CI 0.36, 1.02; p trend 0.01) and HAI women (OR 0.52; 95% CI 0.23, 1.16; p trend 0.07). Additionally, high total MET hours of activity at age 30 years (OR 0.56; 95% CI 0.37, 0.85) and at age 15 years (OR 0.57; 95% CI 0.38, 0.88) reduced breast cancer risk among postmenopausal NHW women not recently exposed to hormones. Among HAI women, more recent activity performed during the referent year and at age 50 appeared to have the greatest influence on breast cancer risk. Among postmenopausal NHW women. there was a significant interaction between physical activity and hormone replacement therapy (p value, 0.01), while among postmenopausal HAI women, physical activity interacted with body mass index (p value, 0.04). These data suggest that physical activity is important in reducing risk of breast cancer in both NHW and HAI women.     

Prostate cancer, benign prostatic hyperplasia and physical activity in Shanghai, China

BACKGROUND: Studies suggest that increased levels of physical activity might decrease the risk of prostate cancer. We ascertained lifetime measures of activity in a population-based case-control study of prostate cancer in Shanghai, China to investigate physical activity in a population where the incidence of prostate cancer is low but rising. METHODS: In all, 238 men with prostate cancer, diagnosed 1993-1995, were identified through a rapid reporting system. A second group of 206 men with benign prostatic hyperplasia (BPH) was matched to prostate cancer cases, and 471 age-matched and population-based controls were identified from urban Shanghai. Through personal interviews, we ascertained all daily, occupational, and recreational activities at ages 20-29, ages 40-49, and in 1988 to generate hours spent sleeping, sitting, in moderate activity, and in vigorous activity. Time spent per week in different activities was converted to metabolic equivalents (MET-h) and energy expended. RESULTS: Time spent in, MET-h of, and energy expended in physical activities were not consistently related to either prostate cancer or BPH when compared to controls. Few men reported regular vigorous activity. Occupational activity, based on an energy expenditure index using job titles, was suggestively associated with a decreased risk of BPH, but not associated with prostate cancer. Associations did not vary according to age or stage of prostate cancer at diagnosis. CONCLUSIONS: Our results, based on regular physical activity, occupational activity, hours in activities, MET-h, and energy expended, did not support a protective role of physical activity in prostate cancer or BPH for men in a low-risk population.     

Impact of consumption of vegetable, fruit, grain, and high glycemic index foods on aggressive prostate cancer risk

Prostate cancer is a common but complex disease, and distinguishing modifiable risk factors such as diet for more aggressive disease is extremely important. Previous work has detected intriguing associations between vegetable, fruit, and grains and more aggressive prostate cancer, although these remain somewhat unclear. Here we further investigate such potential relationships with a case-control study of 982 men (470 more aggressive prostate cancer cases and 512 control subjects). Comparing the highest to lowest quartiles of intake, we found that increasing intakes of leafy vegetables were inversely associated with risk of aggressive prostate cancer [adjusted odds ratio (OR) = 0.66, 95% CI: 0.46, 0.96; P trend = 0.02], as was higher consumption of high carotenoid vegetables (OR = 0.71, 95% CI: 0.48, 1.04; P trend = 0.04). Conversely, increased consumption of high glycemic index foods were positively associated with risk of aggressive disease (OR = 1.64, 95% CI: 1.05, 2.57; P trend = 0.02). These results were driven by a number of specific foods within the food groups. Our findings support the hypothesis that diets high in vegetables and low in high glycemic index foods decrease risk of aggressive prostate cancer.     

Daily total physical activity level and total cancer risk in men and women: results from a large-scale population-based cohort study in Japan

The impact of total physical activity level on cancer risk has not been fully clarified, particularly in non-Western, relatively lean populations. The authors prospectively examined the association between daily total physical activity (using a metabolic equivalents/day score) and subsequent cancer risk in the Japan Public Health Center-based Prospective Study. A total of 79,771 general-population Japanese men and women aged 45-74 years who responded to a questionnaire in 1995-1999 were followed for total cancer incidence (4,334 cases) through 2004. Compared with subjects in the lowest quartile, increased daily physical activity was associated with a significantly decreased risk of cancer in both sexes. In men, hazard ratios for the second, third, and highest quartiles were 1.00 (95% confidence interval (CI): 0.90, 1.11), 0.96 (95% CI: 0.86, 1.07), and 0.87 (95% CI: 0.78, 0.96), respectively (p for trend = 0.005); in women, hazard ratios were 0.93 (95% CI: 0.82, 1.05), 0.84 (95% CI: 0.73, 0.96), and 0.84 (95% CI: 0.73, 0.97), respectively (p for trend = 0.007). The decreased risk was more clearly observed in women than in men, especially among the elderly and those who regularly engaged in leisure-time sports or physical exercise. By site, decreased risks were observed for cancers of the colon, liver, and pancreas in men and for cancer of the stomach in women. Increased daily physical activity may be beneficial in preventing cancer in a relatively lean population.     

Commuting physical activity and risk of colon cancer in Shanghai, China

Colon cancer incidence rates have been rapidly increasing in Shanghai, China, for reasons still unclear. Low physical activity is a known risk factor for colon cancer. The authors examined the effects of physical activity, particularly commuting physical activity, and its joint effects with body mass index on colon cancer risk in a population-based, case-control study. The study included 931 incident colon cancer patients and 1,552 randomly selected controls in Shanghai between 1990 and 1993. Colon cancer risk was significantly reduced among subjects with high commuting physical activity (odds ratio (OR) = 0.52, 95% confidence interval (CI): 0.27, 0.87 for men; OR = 0.56, 95% CI: 0.21, 0.91 for women), particularly among those who had high commuting physical activity for at least 35 years (OR = 0.34, 95% CI: 0.09, 0.76 for men; OR = 0.31, 95% CI: 0.07, 0.72 for women). Commuting physical activity significantly modified the risk conferred by high body mass index, with the highest risk observed among those at the highest quintile of body mass index and the lowest activity level (OR = 6.43, 95% CI: 1.82, 8.54 for men; OR = 7.42, 95% CI: 2.84, 10.01 for women). Our results suggest that regular and frequent physical activity over a long period of time protects from colon cancer and significantly modifies the body mass index-associated risk.     

Impact of Consumption of Vegetable,Fruit, Grain,and High Glycemic Index Foods on Aggressive Prostate Cancer Risk

Prostate cancer is a common but complex disease, and distinguishing modifiable risk factors such as diet for more aggressive disease is extremely important. Previous work has detected intriguing associations between vegetable, fruit, and grains and more aggressive prostate cancer, although these remain somewhat unclear. Here we further investigate such potential relationships with a case-control study of 982 men (470 more aggressive prostate cancer cases and 512 control subjects). Comparing the highest to lowest quartiles of intake, we found that increasing intakes of leafy vegetables were inversely associated with risk of aggressive prostate cancer [adjusted odds ratio (OR) = 0.66, 95% CI: 0.46, 0.96; P trend = 0.02], as was higher consumption of high carotenoid vegetables (OR = 0.71, 95% CI: 0.48, 1.04; P trend = 0.04). Conversely, increased consumption of high glycemic index foods were positively associated with risk of aggressive disease (OR = 1.64, 95% CI: 1.05, 2.57; P trend = 0.02). These results were driven by a number of specific foods within the food groups. Our findings support the hypothesis that diets high in vegetables and low in high glycemic index foods decrease risk of aggressive prostate cancer.     

Habitual physical activity and menopausal symptoms: a case-control study

A case-control study design was used to examine whether habitual physical activity prior to the final menstrual period (FMP) was associated with reduced risk of vasomotor and other symptoms during the perimenopausal period. Both cases and controls were identified through a screening interview with randomly selected women members, ages 48-52, of a large health maintenance organization. Cases (n = 82) were defined as women 3-12 months past their FMP who reported regularly having hot flashes or night sweats at least once a day or night during the 3 months following their FMP. Controls (n = 89) were of the same biologic age with respect to the FMP but reported vasomotor symptoms less than once a week during the reference time period. Neither cases nor controls had a history of hormone replacement therapy (HRT), hysterectomy, or bilateral oophorectomy. Case-control status, habitual physical activity (including recreational, housework, child care, and occupational activity), and psychological and somatic symptoms were assessed by self-report. Participation in vigorous recreational activity during the year prior to the FMP was not associated with reduced risk of frequent vasomotor symptoms after the FMP (odds ratio [OR] = 1.03 for a 50-unit increase in activity score, 95% confidence interval [CI] = 0.97-1.1). This lack of relationship was observed in all domains of activity. Factors that were associated with decreased risk included higher body mass index (BMI) (weight in kg/(height in meters)2) (OR = 0.95 per 1 unit increase in BMI, 95% CI = 0.90-1.00) and higher education (having a college degree relative to less education) (OR = 0.56, 95% CI = 0.40-0.80). Physical activity was also unassociated with reduced risk of psychologic distress, depressive feelings, or somatic symptoms, but, relative to controls, having vasomotor symptoms (being a case) was strongly associated with increased risk of experiencing those symptoms (OR ranging from 1.83 for psychologic distress to 2.84 for depressive feelings). These findings suggest that regular physical activity before the FMP may not reduce the likelihood of experiencing symptoms during the perimenopause, although the small sample size may limit the inferences that can be drawn.     

武汉市前列腺癌的流行病学研究

前列腺癌是欧美国家男性的主要死亡原因，我国还没有全面的发病率和死亡统计资料。为了解我国前列腺癌的流行情况，在武汉市１９９０～１９９２年前列腺癌的发病及死亡报告的基础上，收集了１９９０～１９９５年住院治疗的１０２例前列腺癌现患病例进行了１１配比的病例对照研究。结果显示：武汉市前列腺癌的发病率和死亡率分别为１．３７／１０万和０．７５／１０万，世界人口年平均标化发病率和死亡率分别为１．１０／１０万和０．６６／１０万。泌尿系统病史〔ＯＲ＝５．４２，９５％可信区间（ＣＩ）＝１．５６～１８．８３〕、子女数超过３个（ＯＲ＝２．４３，９５％ＣＩ＝１．１７～５．０２）、青壮年期每周性交超过３次（ＯＲ＝３．３８，９５％ＣＩ＝１．５１～７．５８）、滥用药物（ＯＲ＝４．１１，９５％ＣＩ＝１．６５～１０．２５）、体质指数高（ＯＲ＝２．５８，９５％ＣＩ＝１．３０～５．１１）等是前列腺癌的危险因素，而体力劳动（ＯＲ＝０．３５，９５％ＣＩ＝０．１７～０．７１）、初次遗精年龄晚于１８岁（ＯＲ＝０．２０，９５％ＣＩ＝０．０８～０．５２）等是其保护性因素。     

Education,income, occupational status and health risk behaviour

Aim Socio-economic status is associated with a variety of health-related behaviours. In our study, we determined the independent effects of income, educational attainment and occupational status on overweight, smoking and physical activity in the German population. Subjects and methods The German National Health Interview and Examination Survey is a representative sample of the German adult population and includes 7,124 men and women. Prevalences of obesity, smoking and physical inactivity stratified for education, income and occupational status were calculated. Multiple logistic regression models were used to estimate the odds ratios (OR) and 95% confidence intervals (CI) for education, income, occupational status and health-related behaviour, adjusted for age and gender. Results Health risk behaviours were more prevalent in subjects with lower education, income or occupational status. After mutual adjustment, education, income and occupation were independently associated with physical inactivity. Low education was strongly associated with both obesity (OR: 2.58, 95% CI: 1.99–3.34) and smoking (OR: 2.09, 95% CI: 1.71–2.54). Low income was associated with smoking (OR: 1.40, 95% CI: 1.07–1.83), but not with obesity, and low occupational status was associated with obesity (OR: 1.42, 95% CI: 1.05–1.92), but not with smoking. High income or occupation could not compensate for the impact of low education on obesity and smoking. Conclusion Low socio-economic status is associated with health risk behaviours. Concerning obesity and smoking, education was more important than income or occupational status. Public health programmes to reduce these risk factors should focus on early-life health education.     

Medical history, sexual, and maturational factors and prostate cancer risk

PURPOSE: Sexual, physical, and medical factors were investigated in a case-control study of prostate cancer. METHODS: This population-based study, conducted from 1995 to 1999 in northeastern Ontario, used cancer registry-identified cases (n=760), aged 45 to 84 years, diagnosed between 1995 and 1998. Age-frequency matched controls (n=1632) were obtained from telephone listings. Two separate logistic regression analyses considered: 1) sexual and physical; and 2) medical factors. RESULTS: For the sexual-physical model, marital status, family income, maximum height, number of marriages, having children, age at first marriage, birth, and needing to shave, and acne were not significantly related to risk. In the medical model, a family history of prostate cancer (OR, 2.99; 95% CI, 2.21-4.04) and history of venereal disease (OR, 2.12; 95% CI, 1.27-3.53) were associated with significantly increased risk. A history of allergies (OR, 0.78; 95% CI, 0.60-1.00), benign prostatic hyperplasia (OR, 0.63; 95% CI, 0.49-0.81), and an annual physical exam (OR, 0.43; 95% CI, 0.21-0.85) were associated with reduced risk. Other factors considered in the medical conditions model, body mass index, smoking non-filter cigarettes, and family income were not associated with prostate cancer. CONCLUSIONS: This study is consistent with other studies that suggest that infectious agents may be involved in prostate cancer development.     

Predictors of change in physical activity during and after pregnancy: Project Viva

BACKGROUND: Few studies document longitudinal changes in physical activity from prepregnancy to the postpartum period. METHODS: This study estimated change in self-reported leisure-time physical activity in 1442 women before pregnancy, during the second trimester, and at 6 months postpartum. In addition, it also examined predictors of becoming insufficiently active during or after pregnancy. RESULTS: The mean (SD) age was 32.5 (4.5) years, 34% of the women were overweight or obese prepregnancy (body mass index equal to or greater than 25 kg/m(2)), and 76% were white. Before pregnancy, the mean total leisure physical activity was 9.6 hours per week. The reported decrease in total activity between prepregnancy and 6 months postpartum was -1.4 (95% CI=-1.0 to -1.9) hours per week, accounted for by decreases in moderate and vigorous physical activity but not walking. Prevalence of insufficiently active lifestyle (less than 150 minutes per week of total activity) increased from 12.6% before pregnancy to 21.7% during the postpartum period. The OR for becoming insufficiently active during pregnancy was 1.58 (95% CI=1.07-2.32) in women with at least one child compared with no children. Predictors of becoming insufficiently active postpartum included postpartum weight retention (OR=1.31; 95% CI=1.05-1.58 for each 5-kg increment); working longer hours in the first trimester (e.g., OR=5.12; 95% CI=1.96-13.4 for 45+ vs 0 hours); and reporting that lack of child care was a barrier to physical activity (OR=1.73; 95% CI=0.99-3.02). CONCLUSIONS: Women reported decreases in moderate and vigorous physical activity during pregnancy that persisted at 6 months postpartum. Levels of walking did not decline. Children in the home, longer work hours, and lack of child care were predictors of becoming insufficiently active during or after pregnancy.