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In a Norwegian, prospective study we investigated breast cancer risk in relation to age at, and time since, childbirth, and whether the timing of births modified the risk pattern after delivery. A total of 23,890 women of parity 5 or less were diagnosed with breast cancer during follow-up of 1.7 million women at ages 20-74 years. Results, based on Poisson regression analyses of person-years at risk, showed long-term protective effects of the first, as well as subsequent, pregnancies and that these were preceded by a short-term increase in risk. The magnitude and timing of this adverse effect differed somewhat by birth order, maternal age at delivery and birth spacing. No transient increase in risk was seen shortly after a first birth below age 25 years, but an early first birth did not prevent a transient increase in risk after subsequent births. In general, the magnitude of the adverse effect was strongest after pregnancies at age 30 years or older. A wide birth interval was also related to a more pronounced adverse effect. Increasing maternal age at the first and second childbirth was associated with an increase in risk in the long run, whereas no such long-term effect was seen with age at higher order births. [ABSTRACT FROM AUTHOR]

A cohort of 63 090 Norwegian women born 1886–1928 was followed more than 38 years, and relations between reproductive factors and risk of pancreatic cancer were explored; 449 cases were recorded at ages 50–89 years. Age at menopause showed a moderately positive association with risk (rate ratio (RR)=1.08 per 2 years delay in menopause; 95% confidence interval (CI)=1.00–1.17). Neither parity nor duration of breastfeeding showed significant associations with risk after adjusting only for demographic factors. With mutual adjustment, however, parity became positively associated (RR=1.13 per delivery; 95% CI=1.05–1.22) while duration of breastfeeding was inversely associated (RR=0.87 per 12 months; 95% CI=0.78–0.97). These associations lessened in magnitude with increasing age, and were essentially absent above age 80 years. Risk was raised among women reporting at least one abortion, but no trend was seen with number of abortions. Together with previous studies, the findings raise questions about the role of chance, but do not exclude hormonal factors related to breastfeeding and pregnancy from affecting pancreatic cancer risk.British Journal of Cancer (2008) 98, 189–193. doi:10.1038/sj.bjc.6604095 www.bjcancer.com Published online 13 November 2007 [ABSTRACT FROM AUTHOR]

Background: Anemia in pregnancy is common in Tanzania, but many areas have not been investigated. This study describes prevalence and determinants of anemia among rural pregnant women living at 1300-2200 meters above sea level in Northern Tanzania.Methods: Three thousand eight hundred and thirty-six pregnant women from two rural divisions of Mbulu and Hanang districts attending antenatal clinic between January 1995 and March 1996 were assessed in a cross-sectional study. Blood samples were examined for hemoglobin concentration (Hb) and thick blood slide (BS) for malaria. Information on date of examination, village, age, ethnic and religious affiliation, gestational age, and parity was recorded. Altitude was derived from official maps. Main outcome measures were mean Hb level and risk of anemia defined as a Hb of less than 9.0 g/dl.Results: Hb levels ranged from 4.5 to 18.1 g/dl, and mean was 12.1 g/dl. Twenty-three per cent had a Hb of less than 11 g/dl, 4.6% less than 9 g/dl and 0.5% less than 7 g/dl; standardized to sea level 36.1%, 8.8%, and 1.1%, respectively. The mean Hb increased by 0.3 g/dl per 200 m increased altitude, and the risk of anemia decreased with a factor of 0.6 per 200 m increased altitude. We found higher risk of anemia at higher maternal age (1.2 times increased risk per 5 years). Furthermore, the Datoga tribe had twice the risk of anemia compared with the Iraqw. The risk of anemia was only half at 3-4 months of gestation compared to at 7-8 months. The risk increased six-fold in the rainy season of 1995, and the risk was almost double among those with malaria parasitemia.Conclusions: Anemia in pregnancy was common in this area of high altitude in rural Tanzania, but less prevalent than indicated by studies from most other parts of the country. The study confirms that preventing anemia is a challenge in preventive antenatal care in the highlands of Tanzania. Studies focussing on the specific etiologic agents are needed. [ABSTRACT FROM AUTHOR]

We examined the effects from subjects, technicians and spirometers on within-session variability in successful recordings of forced expiratory volume in 1 second (FEV1 ) and forced vital capacity (FVC) in 4989 asymptomatic never-smoking men. All eligible men aged 30–46 years living in western Norway (n = 45 380) were invited to a cross-sectional community survey. Information on respiratory symptoms, smoking habits and occupational exposures was obtained from a self-administered questionnaire. Three successful FEV1 and FVC recordings were obtained in 26 368 attendants using three dry-wedge bellow spirometers operated by 10 different technicians. Within-subject standard deviation (SD) from three recordings of FEV1 and FVC was on average 102 and 106 ml, respectively, and increased with height (14 and 17 ml, respectively, per 10 cm) and body mass index (BMI) (11 and 14 ml, respectively, per 5 kg m-2 ). Between-subject SD of the mean of three FEV1 and FVC recordings was 591 and 754 ml, respectively, and increased in groups of increasing height (43 and 40 ml, respectively, per 10 cm). Small, but significant, differences were observed between technicians in within-subject SD and in levels of FEV1 and FVC. Homogeneity of between-subject variability, necessary for linear regression analysis, was obtained using FEV1 and FVC divided by height squared. In conclusion, within-subject variability in three successful spirometric recordings was small, but dependent on height and BMI of the subjects as well as technician performance. The observed heterogeneity in between-subject variation in FEV1 and FVC levels disappeared when each variable was divided by height squared. Novel multiple linear regression equations for FEV1 /height2 and FVC/height2 were developed to be used in evaluating the effects from occupational airborne exposures in... [ABSTRACT FROM AUTHOR]

Determinants of multiple sexual partners and condom use among adults were assessed through a population-based survey in one urban, one semi-urban and one rural community in the Arusha region, northern Tanzania. The study samples were obtained by randomly selecting clusters of 10 households from the 3 communities. Informed verbal consent was sought from each respondent for participation in the study. High-risk sexual behaviours and condom use were assessed using a structured questionnaire. It was observed that significantly more men than women reported having multiple sexual partners (49% vs 25.2%; OR = 1.69; 95% CI = 1.51-1.90) and urban men were significantly more likely to report having multiple sexual partners than men in rural areas. In both men and women, early sexual debut was associated with having multiple sexual partners while travel, alcohol use, and sex under the influence of alcohol were significantly associated with multiple sexual partners in men only. AIDS-related discussion was significantly associated with having fewer sexual partners in both men and women. Of the 1551 respondents, 320 (20.6%) reported having ever used a condom and of the 320 respondents who had ever used a condom, 34 (10.6%) reported having used it at the last sexual intercourse. Significantly more men than women reported having ever used a condom (34.1% vs 14.1%; OR = 1.77; 95% CI = 1.56-2.01). In both men and women, early sexual debut and being young, unmarried, travelling out of the Arusha region and having multiple sexual partners were associated with increased condom use. For both men and women, frequent discussion of AIDS with family members or friends was associated with increased condom use. These data suggest that interventions targeting adolescents and young adults may be effective for control of HIV transmission in Tanzania. In particular, creation of opportunities for people to come together and discuss AIDS might be an important strategy. [ABSTRACT FROM AUTHOR]

Objective: To estimate the relations between established cardiovascular risk factors and total homocysteine (tHcy) in plasma.Design: Health examination survey by the Norwegian Health Screening Service in 1992 and 1993.Setting: General community, Hordaland County of Western Norway.Participants: A total of 7591 men and 8585 women, 40 to 67 years of age, with no history of hypertension, diabetes, coronary heart disease, or cerebrovascular disease were included.Main Outcome Measure: Plasma tHcy level.Results: The level of plasma tHcy was higher in men than in women and increased with age. In subjects 40 to 42 years old, geometric means were 10.8 mumol/L for 5918 men and 9.1 mumol/L for 6348 women. At age 65 to 67 years, the corresponding tHcy values were 12.3 mumol/L (1386 men) and 11.0 mumol/L (1932 women). Plasma tHcy level increased markedly with the daily number of cigarettes smoked in all age groups. Its relation to smoking was particularly strong in women. The combined effect of age, sex, and smoking was striking. Heavy-smoking men aged 65 to 67 years had a mean tHcy level 4.8 mumol/L higher than never-smoking women aged 40 to 42 years. Plasma tHcy level also was positively related to total cholesterol level, blood pressure, and heart rate and inversely related to physical activity. The relations were not substantially changed by multivariate adjustment, including intake of vitamin supplements, fruits, and vegetables.Conclusions: Elevated plasma tHcy level was associated with major components of the cardiovascular risk profile, ie, male sex, old age, smoking, high blood pressure, elevated cholesterol level, and lack of exercise. These findings should influence future studies on the etiology and pathogenesis of cardiovascular disease. [ABSTRACT FROM AUTHOR]

The aim of the study was to investigate the impact of reproductive variables (age at menarche, menopause, first and last birth as well as parity, lactation, and abortions) on hip fracture mortality. A prospective study in Norway with more than 60,000 women followed up for 29 years. A total of 465 deaths as a result of hip fracture were recorded. Statistically significant linear relations (p < or = 0.02) were found between both age at menarche and length of reproductive period (defined as age at menopause to age at menarche) and the mortality of hip fractures in women aged less than 80. The death rate for women with a late menarche (> or = 17 years) was twice that of the women with relatively early menarche (< or = 13 years). Compared with women with less than 30 years between menopause and menarche, the mortality rate ratio in women with more than 38 reproductive years was 0.5. We also found an inverse relation with age at first birth. This study supports by hypothesis that an early menarche and a long reproductive period protect against hip fracture mortality. High age at first birth may also be protective. [ABSTRACT FROM AUTHOR]

The evidence regarding reproductive events as risk factors for rheumatoid arthritis (RA) is not conclusive. In the present study a population-based cohort consisting of 63 090 women were followed from 1961 to 1989. Detailed data on reproductive factors were collected through personal interviews in the period 1956–9. The endpoint used was mention of RA on the death certificate. Mortality rate ratios were estimated by Poisson regression, controlling for various demographic variables. During 1 485 400 person-yr of observation, a total of 355 cases with RA mentioned on the death certificate were identified. Total time of lactation was associated with a decreased mortality of RA, with an approximate dose–response relationship. The results did not support a role of parity, age at first and last birth, or age at menarche’and menopause in the development of RA. This protective effect of lactation on the development of RA has not previously been described, and since a definite biological explanation is lacking, the association should be confinned in other populations. [ABSTRACT FROM PUBLISHER]

Background: Few prospective studies relating childbearing to total and cause-specific mortality and cancer incidence have been published. The purpose of this paper was to examine these relations in a large cohort of Norwegian women.Methods: Information on reproductive factors was obtained through interviews with 63,090 women. All deaths and cancer cases during follow-up, 1961-1980, were obtained by linkage to the files at the Central Bureau of Statistics and the Cancer Registry of Norway, respectively. Associations with parity were assessed by stratified logistic regression.Results: For cerebrovascular and ischaemic heart disease, moderate but highly significant positive trends of increasing mortality with increasing parity were observed in the older part of the cohort. Deaths from diseases of the respiratory system and suicide were most common among nulliparous women. Inverse associations with parity were observed for cancers of the breast, corpus uteri and ovaries as well as for melanoma and non-melanoma skin cancers. Positive associations were observed for cancer of the cervix uteri in all age groups, for cancer of the respiratory system among older women and for pancreatic cancer and multiple myelomas in the younger part of the cohort. The results gave no support to previous reports of positive associations with cancer of the liver or gallbladder.Conclusions: The study supports evidence of an increased risk of ischaemic heart disease in multiparous women, which had been observed previously in three smaller prospective studies. It confirms earlier observations of low risks of cancer of the breast, corpus uteri and ovaries in women with high parity. [ABSTRACT FROM AUTHOR]

A cross-sectional study was conducted to evaluate the effect of a community-based health education intervention programme and to study the determinants of night blindness in Bangladesh. The intervention programme was implemented to reduce the morbidity of nutritional blindness (night blindness) in the northern part of Bangladesh (Ranjpure district) during 1986–1989. A baseline study in 1986 covered 2010 households with a total population of 11 600, and the evaluation study in 1989 covered 2011 households with a total population of 10 456. Prevalence of night blindness was studied among children aged <9 years in these households. The prevalence of night blindness per 1000 children was reduced significantly during the intervention period from 50.7 in 1986 to 26.7 in 1989. However, the post-intervention prevalence varied significantly between areas. Multivariate analyses showed that consumption of fish, meat, milk or eggs, dark green leaf vegetables, yellow fruits and vitamin A capsules were significant predictors of night blindness. In addition, family income, mother's literacy, family size and area of residence exhibited strong and statistically significant associations with night blindness in the 1989 cross-sectional study. The prevalence of night blindness was highest among 4–6 year old girls and 7–8 year old boys. The sex difference was, however, not statistically significant. [ABSTRACT FROM PUBLISHER]

Relations between previous lactation experience and risks of cancer of the breast and other sites were investigated after follow-up of 50,274 parous women from 1961 through 1980. Among women with complete information on lactation, 5102 developed cancer and, of these, 1136 were diagnosed with breast cancer. Analyses of associations with mean duration of lactation per birth and duration for each of the three first births suggested a nonlinear relation to breast cancer. The highest risk was observed for those with intermediate duration of breast feeding, whereas lower risks were found among those with very short or very long duration. For all nongenital cancers combined, decreased risks were observed among those with the longest duration of breast feeding. However, among cancers of specific sites, a significant inverse association was found for pancreatic cancer only. The overall impression given by our data is that breast feeding is not strongly related to risks of breast cancer or any other common cancer. [ABSTRACT FROM AUTHOR]