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PubMed1990

National General Practice Study of Epilepsy: recurrence after a first seizure.

In the National General Practice Study of Epilepsy 564 patients classified as having definite seizures have been followed up for 2-4 years. 67% (95% confidence interval 63-71%) had a recurrence within 12 months of the first seizure, and 78% (74-81%) had a recurrence within 36 months. Seizures associated with a neurological deficit presumed present at birth had a high rate of recurrence (100% by 12 months), whereas seizures that occurred within 3 months of an acute insult to the brain, such as head injury or stroke, or in the context of an acute precipitant such as alcohol, carried a much lower risk of recurrence (40% [29-51%] by 12 months). Other factors affecting the risk of recurrence were age-the highest risk being for patients under the age of 16 (83% [77-89%] by 36 months) or over the age of 59 (83% [76-90%] by 36 months-and type of first seizure-the risk of recurrence being much higher for patients with simple partial or complex partial seizures (94% [90-99%] by 36 months) than for those with generalised tonic clonic seizures (72% [67-77%] by 36 months).

Actuarial Analysis↗
PubMedDate not supplied

[Nation-wide registration of limb deficiencies in Germany].

AIM: A detailed registration of the frequency and the aetiology of limb deficiencies has been established for the first time in Germany. METHOD: According to the ESPED model (Documentation of rare paediatric diseases in Germany) we send out at an interval of three months a questionnaire for registration of live births, still births and their limb deficiencies to 1 073 gynaecological hospitals. In case of a positive response for a limb deficiency a second questionnaire is sent for details about pregnancy, birth and family. The limb defects are registered according to the ICD-10 classification and statistically analysed. RESULTS: Current acquisition period: 48 months (April 2000-April 2004). Total number of registered births: 1 070 541. Number of live births with limb deficiencies: 1 534 (0.14 %). Number of still births with limb deficiencies: 55 (1.7 %). Minor limb deficiencies such as polydactyly (22.4 %) are more frequent than major deficiencies of the tibia (1.0 %) or of the fibula (1.6 %). A familiar disposition is found in 9.7 %. A correlation to the profession of parents or their age (mother: 29, father: 33), or nicotine abuse could not be detected. The numbers of special features during pregnancy (amniocentesis in 3.3 %, oligohydramnion in 0.5 %, polyhydramnion in 0.3 %, etc.) and during delivery (relation between normal delivery and caesarean section = 59.5 %/29 %, etc.) were similar to the frequencies in the normal population. CONCLUSIONS: Our register represents the largest study world-wide in respect to the birth rate and the most accurate record of limb deficiencies. In the current acquisition period no correlation of the registered limb deficiencies to environmental effects, individual misbehaviour, exposed professional group and peculiarities during pregnancy and parturition could be found. The continuation of our register is essential for further detection of the incidence and aetiology of limb defects.

Abnormalities, Multiple↗
PubMedDate not supplied

Infectious disease mortality in two Outer Hebridean islands: 1. measles, pertussis and influenza.

OBJECTIVES: The purpose of the study was to examine changes in mortality from measles, pertussis (whooping cough) and influenza (all epidemic diseases) in Harris and Barra, two Outer Hebridean islands, from 1855 to 1990, and to compare the findings with those from Scotland as a whole over the same period. It was also intended to relate changes in mortality to those in social and economic factors. MATERIALS AND METHODS: Ages and causes of death in Harris and Barra were ascertained from copies of death certificates held at the General Register Office, Edinburgh, and for Scotland as a whole from the Annual Reports of the Registrars General for Scotland. Data were standardized by calculating the Proportionate Mortality Ratio (PMR), the proportion of deaths due to a particular cause to all deaths over a given period. Spectral analysis was employed to examine the durations of epidemic cycles. RESULTS: Ages at death increased slightly over the period of the study. For measles and pertussis, other than for the former in Harris, there were significant relationships between numbers of deaths per decade, and numbers of new susceptibles, estimated as the numbers of births. Epidemics of measles and pertussis in the islands occurred at intervals, usually separated by years of no mortality. The highest PMRs were generally during the later decades of the 19th and first decade of the 20th centuries; this may have been related to the economic problems of agriculture and fishing, and to increasing population density. Influenza epidemics were more frequent than those of the other two diseases. For all three diseases in both islands, there were significant negative power relationships between epidemic size and frequency of occurrence; those in Harris were the stronger. The relationships between length and frequency were significant only in Harris. Generally, epidemic lengths seemed less variable than sizes, possibly because of the rather 'coarse' units of length (quarters) employed. Spectral analysis of the 'detrended' data for the period before the introduction of specific immunoprophylaxis revealed that for measles the main epidemic cycle in all three populations was between 7.3 and 7.8 years' duration. Barra and Scotland had additional 2.5- and 2-year cycles, respectively. For pertussis, Harris and Barra had main cycles of 7.4 years. Harris had an additional cycle of 3.2 years. Scotland had cycles of 4 and 2 years. For influenza, Harris had a main cycle length of 7.4 years, and a less-defined one of about 2.6 years. Barra had a main cycle of 6.9 years, and a subsidiary one of 2 years. Scotland has a single cycle of 8 years. Cubic regressions of the spectral densities on cycle frequencies showed large coefficients for Harris and Barra, but small ones for Scotland. Measles coefficients were closely similar in the two islands, but not those for pertussis. CONCLUSIONS: The findings demonstrate the episodic occurrence of epidemics of these three diseases in the two islands, as against their continual presence in the much larger population of Scotland. They reveal also the decreasing importance of these causes of death in all three populations. The data from Harris and Barra suggest that measles is a more epidemiologically 'stable' disease than pertussis. Both islands appear to obey Hamer's law of 'mass action'. The relatively long intervals between epidemics in the islands may be due partly to their isolation, and partly to the slow accumulation of sufficient numbers of susceptibles to enable an epidemic to occur.

Adolescent↗
PubMed2004

Premature death among teenage mothers.

OBJECTIVE: Some data suggest an association between teenage childbearing and premature death. Whether this possible increase in risk is associated with social circumstances before or after childbirth is not known. We studied premature death in relation to age at first birth, social background and social situation after first birth. DESIGN: Population-based cohort study. SETTING: Women born in Sweden registered in the 1985 Swedish Population Census. POPULATION: Swedish women born 1950-1964 who had their first infant before the age of 30 years (N= 460,434). METHODS: Information on the women's social background and social situation after first birth was obtained from Population Censuses. The women were followed up with regard to cause of death from December 1, 1990 to December 31, 1995. Mortality rate ratios and 95% confidence intervals (CI) were calculated. MAIN OUTCOME MEASURES: Mortality rates by cause of death. RESULTS: Independent of socio-economic background, teenage mothers faced an increased risk of premature death later in life compared with older mothers (rate ratio 1.6, 95% CI 1.4-1.9). The increased risk was most evident for deaths from cervical cancer, lung cancer, ischaemic heart disease, suicide, inflicted violence and alcohol-related diseases. Some, but not all, of these increases in risk were associated with the poorer social position of teenagers mothers. CONCLUSIONS: Teenage mothers, independent of socio-economic background, face an increased risk of premature death. Strategies to reduce teenage childbearing are likely to contribute to improved maternal and infant health.

Adolescent↗
PubMed1976

Weight gain in infancy and physical development between 7 and 10 1/2 years of age.

Heights and weights were measured in 963 10-year-old children, whose weight data from the first year of life were available. Rapid weight gain in infancy was arbitrarily defined on the basis of sex-specific percentiles of weight gain at four-month intervals and from birth to 12 months. In girls, no significant association between rapid weight gain in infancy and overweight at 10 1/2 years was found. In boys, the association was significant for severe overweight (greater than 120% of standard weight for height). An estimation of the possible benefit of an intervention programme (food restriction in all male infants with rapid weight gain) showed, however, that at the very best 12% of the boys treated in this way could be expected to gain some benefit. The result of a correlation analysis between weight gain in infancy and change in height and relative weight between 7 and 10 1/2 years suggested that the factors which determined weight gain in infancy were no longer operative at ages between 7 and 10 1/2 years.

Anthropometry↗
PubMed1993

Neonatal cardiovascular dynamics in relation to matroclinous and patroclinous history of high blood pressure.

Genetic risk is a primary contributing factor to the predisposition of a newborn child to elevated blood pressure later in life. An index of this factor is needed to assess in the neonate the success or failure of preventive interventions instituted for the pregnant women. This index could be based on characteristics of blood pressure and heart rate variability measured during the first 2 days after birth. In the search for such an index, the systolic and diastolic blood pressures and heart rates of 127 newborn babies were automatically monitored at about 30-min intervals for 48 h with a Nippon Colin device, starting early after birth. Circadian parameters (obtained by the linear least-squares fit of a 24-h cosine curve to each individual series) and descriptive statistics for the three circulatory variables were used in a multiple regression analysis to compute a linear prediction function for the cardiovascular risk score. This score was obtained for each neonate on the basis of the presence or absence of overt cardiovascular disease, elevated blood pressure, or obesity across two generations, those of the newborn's parents and grandparents. Results from regression indicate that the best model includes the circadian amplitudes of systolic and diastolic blood pressure and the circadian ranges of systolic blood pressure and heart rate. The contributions from patroclinous versus matroclinous family history were then compared. Results show that linear prediction models include the same variables for both paternal and maternal cardiovascular risk score. These results provide a neonatal index of cardiovascular risk, to be used later for the evaluation of the effects on the newborn of intervention for the pregnant women.

Blood Pressure↗
PubMed1997

Reproductive factors, oral contraceptive use, and risk of colorectal cancer.

Multiparity and use of oral contraceptives are hypothesized to reduce risk of colorectal cancer. Among 57,529 women, 31-90 years of age, who volunteered for a nationwide breast cancer screening program from 1973 to 1980, we observed 154 pathologically confirmed cases of colon cancer and 49 cases of rectal cancer in up to 10 years of follow-up (388,555 person-years). Parity was not associated with risk of colorectal cancer [age-adjusted rate ratio for > or = 4 children vs no children = 1.0; 95% confidence interval (CI) = 0.72-1.5], although decreases in proximal colon cancer and increases in distal colon cancer were observed among parous women. The effect of parity did not vary by age at diagnosis. We found no strong or consistent association for age at menarche, age at first birth, or age at natural menopause. In addition, oral contraceptive use, reflecting mainly past use, was unrelated to risk of colorectal cancer (rate ratio = 1.0; 95% CI = 0.75-1.4). These findings do not corroborate the hypothesis that reproductive events or oral contraceptives influence the development of colorectal cancer.

Adult↗
PubMed1999

Influence of parental smoking on respiratory symptoms during the first decade of life: the Tucson Children's Respiratory Study.

Compelling evidence suggests a causal relation between exposure to parental cigarette smoking and respiratory symptoms during childhood. Still, the roles of prenatal versus postnatal parental smoking need clarification. In this study, the authors assessed the effects of passive smoking on respiratory symptoms in a cohort of over 1,000 children born during 1980-1984. The children were enrolled in the Tucson Children's Respiratory Study in Tucson, Arizona, and were followed from birth to age 11 years. The population was generally middle class and consisted of two main ethnic groups, non-Hispanic Whites (75%) and Hispanics (20%), reflecting Tucson's population. Information on parental smoking and on wheeze and cough in their children was elicited from parents by using questionnaires at five different surveys. Data were analyzed both cross-sectionally and by using the generalized estimation equation approach, a longitudinal mixed-effects model. The best-fitting model indicated that maternal prenatal but not postnatal smoking was associated with current wheeze (odds ratio = 2.3, 95% confidence interval 1.4-3.8) independently of a family history of asthma, socioeconomic factors, and birth weight. This effect was time dependent and significant only below age 3 years; although independent of gender, the association was stronger for girls (odds ratio = 3.6, 95% confidence interval 1.6-8.0). Cough was not associated with parental smoking during the first decade of life. This transitory effect of maternal prenatal smoking on wheezing could be due to changes that affect the early stages of lung development.

Adult↗
PubMed2006

Children born small for gestational age (SGA) who fail to achieve catch up growth by 2-8 years of age are short from infancy to adulthood. Data from a cross-sectional study of 486 Spanish children.

AIMS AND METHODS: Postnatal growth was evaluated in a cross-sectional study of 486 Spanish children, 241 girls and 245 boys, born small for gestational age (SGA), without height catch-up growth between the ages of 2 and 8 years [height <-2SD of age- and sex-matched controls born appropriate for gestational age (AGA)]. SGA was defined as birth weight and/or length values <-2SD of those of the born AGA control population. Weight and height values were grouped in 0.5+/-0.15-year intervals from birth to adult height and compared with those of age- and sex-matched controls born AGA. A total of 1,985 height measurements were recorded in girls and 2,113 in boys. Adult or near-adult height was reached in 50 girls and 42 boys. Mean, SD and mean Z-score values at each age interval were calculated. Dysmorphic syndromes and chronic illnesses were excluded. RESULTS: Mean height Z-score values ranged from -5.56 to -3.12 during the first two years of life and remained between -5.25 and -2.42 thereafter until adult height, and mean weight Z-score values ranged from -3.66 to -2.26 from birth to two years of age and remained between -3.05 and -0.94 thereafter until adult height. Mean Z-score values of near-adult or adult height were -2.83 in girls (n=50) and -2.74 in boys (n=42). Midparental adult height corrected for sex was -1.45 +/- 0.5 in girls (n=150) and -1.60 +/-0.6 in boys (n=185). Height +2SD values of SGA children were similar to -2SD values of age- and sex-matched AGA controls (non statistically significant). CONCLUSIONS: Our data show that short children born SGA are shorter than children born AGA from the age of two years onwards and that their adult height is below that of their corresponding midparental height by more than 1 SD.

Adolescent↗
PubMed1985

Control of time of parturition in pigs.

Injection of prostaglandin (PG) F-2 alpha or its analogues has provided a technique to induce parturition after Day 110 of gestation in the sow. The mean interval from PG injection to parturition ranges from 24 to 28 h, but only 50-60% of the sows farrow during an 8-10 h working day, and as many as 20% of sows may begin parturition before the injection of PG or less than 22 h after the injection. The duration of parturition is positively associated with the incidence of stillbirths and perinatal death so that techniques to reduce the duration of parturition may save piglets. Early parturition has been prevented by feeding sows progestagens, PG synthesis inhibitors and hypothalamic function inhibitors. These compounds were detrimental to piglet survival if they delayed parturition too long after the expected time of parturition. Parturition was delayed in sows up to 1.5 days by altrenogest, 1.6 days by meclofenamic acid, 2.7 days by indomethacin, and 3 days by methallibure without increased incidence of stillborn piglets compared with control sows. Injection of PG after administration of altrenogest or meclofenamic acid was successful in experiments with sows; parturition could be confined to a 5-day working week with no increase in stillborn piglets compared with control sows. Relaxin injected at 48 and 24 h before or only 24 h before injection of PG increased the proportion of sows farrowing 22-32 h after PG to 86.2% compared with sows injected only with PG (53.3%, P less than 0.01). Oxytocin injected 20 h after injection of PG increased the proportion of sows farrowing 20-28 h after PG to 90.4% compared with sows injected only with PG (49.2%, P less than 0.005). Injection of 25-60 i.u. ACTH on Day 110 of gestation did not shorten the length of gestation, but did decrease the incidence of still born piglets by 0.2 piglets/litter (P less than 0.05). An injection of the beta-adrenergic antagonist, carazolol, during labour before the birth of the first piglet decreased the duration of parturition and the incidence of stillborn piglets particularly in primiparous sows (P less than 0.05). Carazolol injected with oxytocin 20 h after injection of PG decreased the interval from PG to parturition by 2 h compared with sows injected with only PG and oxytocin.(ABSTRACT TRUNCATED AT 400 WORDS)

Adrenergic beta-Antagonists↗
PubMed1995

Effects of age at first-pairing on the reproductive performance of Mongolian gerbils (Meriones unguiculatus).

Effects of age at first-pairing on the reproductive performance of the gerbil were studied throughout the reproductive life. Six groups of 7-30 female gerbils were paired monogamously with males at different ages. Out of 101 pairs in 6 groups, 79 (78.2%) produced 1 or more litters. The mean litter size at birth and mean weaning rate of 846 litters were 4.4 (totally 3,733 pups) and 67.4% (2,517 pups), respectively. Reproduction was compared in the 6 age groups. The littering rate (No. of females with litters/No. of female paired) was significantly lower in two groups in which mature females were paired with age-matched males (Group 4) or the oldest females with younger, sexually mature males (Group 6). The interval from pairing to the first litter was shortest in two groups in which mature females were paired with one month older, sexually mature males (Groups 3 and 5). Although the oldest pairs (Group 6) produced about 7 litters, the pairs from the other 5 groups produced about 10 or more litters throughout their reproductive life. The weaning rate was significantly higher in Group 6 (the oldest pairs) than in the younger groups. The effects of parity on reproduction were estimated from the data for the 61 pairs which produced more than 8 litters in the 6 groups. The number of pups at birth and the weaning rate were decreased in last 20-30% of the total parity in all 6 groups, although the age at the last litter in all groups was significantly different. The data suggest that any decline in reproduction may be due to not age but parity in the Mongolian gerbil.

Aging↗
PubMed2001

Induced abortion and placenta complications in the subsequent pregnancy.

BACKGROUND: To study the risk of placenta complications following an induced abortion as a function of the interpregnancy interval. METHODS: This study is based on three Danish national registries; the Medical Birth Registry, the Hospital Discharge Registry, and the Induced Abortion Registry. All primigravida women from 1980 to 1982 were identified in these three registries. A total of 15,727 women who terminated the pregnancy with a first trimester induced abortion were selected to the abortion cohort, and 46,026 women who did not terminate the pregnancy with an induced abortion constituted the control cohort. By register linkage all subsequent pregnancies were identified from 1980 to 1994. Only women who had a non-terminated pregnancy following the index pregnancy were selected to the study. Placenta complications were identified using either the Hospital Discharge Registry ICD-8 codes or the Medical Birth Registry records. RESULTS: A slightly higher risk of placenta complications following an abortion was found. Retained placenta occurred more frequently in women with one, two or more previous abortions, compared with women without any previous abortion of similar gravidity. Adjusting for maternal age and residence at time of pregnancy, the interpregnancy interval, and the number of previous miscarriages (control cohort only), the odds ratios of retained placenta in deliveries of singleton live births in women with one previous abortion was 1.17 (95%CI=1.02-1.35), and for women with two or more previous abortions it was 1.68 (95%CI=1.23-2.30), respectively, compared with the control cohort of similar gravidity. Only for women who had one abortion did the results follow the predicted pattern of a higher risk of retained placenta after a short pregnancy interval. No association with placenta previa was seen. CONCLUSIONS: The findings suggest a positive association between abortions and retained placenta in subsequent singleton live births, but the association was weak and confounding cannot be ruled out.

Abortion, Induced↗
PubMed1996

Relationship between survival status of first child and subsequent child death.

This paper examines the association between infant mortality of the first born and subsequent children using data from rural Bangladesh collected during the period 1971-82. It shows that birth spacing and age of mother at the time of the second birth are important predictors of the survival status of the first child. The findings are discussed in terms of policy implications.

Bangladesh↗
PubMed1999

Reproductive history and stage of breast cancer.

A woman's reproductive history influences her risk of breast cancer. The authors hypothesized that reproductive history also influences stage of disease at the time of diagnosis. The authors analyzed a population-based cohort of 1.5 million Danish women born between 1935 and 1978 for whom individual information on births was available. Between 1978 and 1994, 10,790 incident cases of breast cancer in women under 60 years of age were identified. Nulliparous women compared with parous women and women with a late age at first birth compared with an early age were at significantly increased risk of being diagnosed with a large tumor and with cancer that had spread to regional lymph nodes. However, such an association was not seen for women diagnosed with a small tumor and women with cancer that had not spread to regional lymph nodes. Reproductive history did not appear to influence the time interval from first symptoms to first physician visit ("patient delay") or the time interval from first physician visit to surgery ("doctor delay"). The authors conclude that reproductive history is associated both with incidence of breast cancer and with stage of the disease at diagnosis, indicating possible influences on tumor progression and growth rate. Intensified awareness is warranted to achieve earlier diagnosis among nulliparous women and women with a late age at first childbirth, with the hope of improving their prognosis.

Adult↗
PubMed2005

Fungal levels in the home and allergic rhinitis by 5 years of age.

Studies have repeatedly demonstrated that sensitization to fungi, such as Alternaria, is strongly associated with allergic rhinitis and asthma in children. However, the role of exposure to fungi in the development of childhood allergic rhinitis is poorly understood. In a prospective birth cohort of 405 children of asthmatic/allergic parents from metropolitan Boston, Massachusetts, we examined in-home high fungal concentrations (> 90th percentile) measured once within the first 3 months of life as predictors of doctor-diagnosed allergic rhinitis in the first 5 years of life. In multivariate Cox regression analyses, predictors of allergic rhinitis included high levels of dust-borne Aspergillus [hazard ratio (HR) = 3.27; 95% confidence interval (CI), 1.50-7.14], Aureobasidium (HR = 3.04; 95% CI, 1.33-6.93), and yeasts (HR = 2.67; 95% CI, 1.26-5.66). The factors controlled for in these analyses included water damage or mild or mildew in the building during the first year of the child's life, any lower respiratory tract infection in the first year, male sex, African-American race, fall date of birth, and maternal IgE to Alternaria > 0.35 U/mL. Dust-borne Alternaria and nonsporulating and total fungi were also predictors of allergic rhinitis in models excluding other fungi but adjusting for all of the potential confounders listed above. High measured fungal concentrations and reports of water damage, mold, or mildew in homes may predispose children with a family history of asthma or allergy to the development of allergic rhinitis.

Boston↗
PubMed1993

Breast cancer risk in mothers of multiple births.

Data from an international case-control study of breast cancer that was conducted in the 1960s were used to examine whether multiple births affect the risk of breast cancer in the mother. Among 2821 parous breast-cancer patients, 88 had had one or more multiple births, whereas among 8882 controls 247 had had one or more multiple births; the logistic-regression-adjusted odds ratio (OR) was 1.21, the 95% confidence interval (CI), 0.94 to 1.55. The OR was significantly elevated during the 15-year period following the latest multiple birth (1.76; CI, 1.12 to 2.75), but declined toward the null afterwards. A late first pregnancy imparted a substantially higher breast-cancer risk when it was multiple rather than singleton; the OR was 2.34 for a multiple and 1.48 for a singleton first pregnancy when the cutoff point was 30 years, and 4.58 and 1.57, respectively, when the cutoff point was 35 years. Since multiple pregnancies are characterized by higher levels of pregnancy estrogens, the results of this study would be compatible with the hypothesis that these hormones may be responsible for the transient increase in breast-cancer risk following a term pregnancy and, in particular, a multiple term pregnancy. The long-term reduction of breast-cancer risk is probably due to a different mechanism, most likely the terminal differentiation of susceptible mammary-gland cells.

Adult↗
PubMed1997

Variation in the incidence of uterine leiomyoma among premenopausal women by age and race.

OBJECTIVE: To quantify the incidence of uterine leiomyoma confirmed by hysterectomy, ultrasound, or pelvic examination according to age and race among premenopausal women. METHODS: From September 1989 through May 1993, 95,061 premenopausal nurses age 25-44 with intact uteri and no history of uterine leiomyoma were followed to determine incidence rates of uterine leiomyoma. The self-reported diagnosis was confirmed in 93% of the medical records obtained for a sample of cases. Using pooled logistic regression, we estimated relative risks (RRs) of uterine leiomyoma according to race and examined whether adjustment for other potential risk factors could explain the variation in the race-specific rates. RESULTS: During 327,065 woman-years, 4181 new cases of uterine leiomyoma were reported. The incidence rates increased with age, and the age-standardized rates of ultrasound- or hysterectomy-confirmed diagnoses per 1000 woman-years were 8.9 among white women and 30.6 among black women. After further adjustment for marital status, body mass index, age at first birth, years since last birth, history of infertility, age at first oral contraceptive use, and current alcohol consumption, the rates among black women were significantly greater for diagnoses confirmed by ultrasound or hysterectomy (RR 3.25; 95% confidence interval [CI] 2.71, 3.88) and by hysterectomy (RR 1.82; 95% CI 1.17, 2.82) compared with rates among white women. We observed similar RRs when the cohort was restricted to participants who reported undergoing a screening physical examination within the 2 years before baseline. CONCLUSION: A higher prevalence of known risk factors did not explain the excess rate of uterine leiomyoma among premenopausal black women.

Adult↗
PubMed2000

The effect of physical activity on breast cancer risk: a cohort study of 30,548 women.

BACKGROUND: In epidemiological studies abundant physical activity has been related to decreased breast cancer risk, though the results have been inconsistent. The purpose of this paper was to study the association of physical activity at leisure and commuting to work and incidence of breast cancer. METHODS: The study cohort consisted of 30,548 female participants of the Finnish adult health behaviour survey, based on annual random samples of Finns aged 15-64, collected in 1978-1993. By the end of 1995, 332 breast cancer cases had been diagnosed in the cohort. Relative risks of breast cancer were adjusted for age at survey, body mass index (BMI), education, length of follow-up, parity and age at first birth using Poisson regression models. RESULTS: Compared to women exercising less than once a week, the adjusted relative risk of breast cancer for women exercising once a week was 0.80 (95% confidence interval (CI): 0.58-1.10), for women exercising 2-3 times per week 0.92 (95% CI: 0.78-1.22) and for women exercising daily 1.01 (95% CI: 0.72-1.42). Women who reported commuting, walking or bicycling to work 30 min or more daily had slightly lower adjusted risk of breast cancer (RR: 0.87, 95% CI: 0.62-1.24) than women working at home, being unemployed or driving a car to working place. CONCLUSION: Although a small protective effect of regular physical activity for breast cancer incidence was found in physical activity when commuting to work, the role of the physical activity in breast cancer prevention is still an open question.

Adolescent↗