Risk factors for hip fracture and a possible effect modification by hormone replacement therapy. The Danish nurse cohort study.

OBJECTIVE: To identify risk factors for hip fracture and to examine whether hormone replacement therapy (HRT) modifies the effect of these risk factors. DESIGN: Prospective cohort study. SETTING: The Danish Nurse Cohort Study. PARTICIPANTS: 14,015 female nurses aged 50 years and above who in 1993 completed a questionnaire on general health and lifestyle issues, reproductive history including information on HRT, and family history of osteoporosis and personal history of a wrist fracture. OUTCOME MEASURES: End-point was the first-ever hip fracture registered in the Danish National Hospital Register during the period from 1993 to 1999. RESULTS: During the follow-up period 245 hip fractures were identified. Ever users of HRT had a lower risk of hip fracture (hazard ratio 0.69; 0.50-0.94). Women reporting a poor health (hazard ratio 2.01; 1.30-3.11), restrictions in daily activities (hazard ratio 1.52; 1.05-2.21), low body mass index (hazard ratio 1.65; 0.98-2.77), and leisure time sedentary physical activity (hazard ratio 1.88; 1.30-2.70) were main identified risk factors for hip fracture. HRT did not modify the effect of risk factors on the risk of hip fracture. CONCLUSION: This study confirms that women with a frail health are at increased hip fracture risk and that ever use of HRT decreases the risk of hip fracture. HRT did not modify the effect of these risk factors, indicating that the preventive effect of this therapy is independent of risk factors.

Alcohol intake, type of beverage, and risk of breast cancer in pre- and postmenopausal women.

BACKGROUND: Most studies of the relation between alcohol consumption and breast cancer have shown a modestly increased risk, although the results are still conflicting. METHODS: The aim of this prospective population-based cohort study was to assess the influence of alcohol intake and type of beverage (beer, wine, or spirits) on breast cancer risk in relation to menopausal status. Among 13,074 women aged 20 to 91 years, we examined the relationship between breast cancer risk, total alcohol intake, and type of alcohol in relation to menopausal status. The women were classified as premenopausal or as postmenopausal at younger than 70 years or 70 years or more. RESULTS: During follow-up, 76 premenopausal and 397 postmenopausal women developed breast cancer. Premenopausal women who had an intake of more than 27 drinks per week had a relative risk of breast cancer of 3.49 (95% confidence limits, 1.36-8.99) compared with light drinkers (p = 0.011), whereas there were no differences in risk in the lower-intake categories. The increased risk of breast cancer among premenopausal women was independent of the type of alcohol. Postmenopausal women older than 70 years of age who had an intake of more than six drinks per week of spirits had a relative risk of breast cancer of 2.43 (95% confidence limits, 1.41-4.20) compared with women who consumed less than one drink of spirits per week (p = 0.0014). CONCLUSIONS: Total alcohol intake of more than 27 drinks per week increases breast cancer risk in premenopausal women independently of the type of alcohol. Among postmenopausal women, an intake of spirits of more than six drinks per week increases breast cancer risk.

The validity of self-reported fractures among Danish female nurses: comparison with fractures registered in the Danish National Hospital Register.

BACKGROUND: The authors compared self-reported non-spine fractures obtained from a cohort of Danish female nurses with fracture diagnoses registered in the Danish National Hospital Register (DNHR). METHOD: The self-reported fracture history was obtained from a questionnaire and was related to fracture information registered with the DNHR by means of the unique person identification code of Danish citizens. A total of 166 self-reported hip fractures, 391 self-reported wrist fractures, and 121 self-reported upper arm fractures were available for the comparison. The self-reported fractures were initially compared with the anatomic specific fracture diagnoses registered in the DNHR. Second, the comparison also included fracture diagnoses of adjacent skeletal sites (unspecific fracture diagnoses). RESULTS: The positive predictive value of a positive report of hip fracture was 89%. Inclusion of unspecific registered hip fractures increased the positive predictive value to 94%. The same figures for wrist fractures were 75% and 84%, respectively, and for upper arm fractures 54% and 83%, respectively. The predictive value of a negative report of hip fracture was 99.5%. The fracture year was correctly reported in 76% of the hip fracture cases, 81% of the wrist fracture cases, and 82% of the upper arm fracture cases. Predictors of false-positive report of fractures were young age ( < 60 years), report of indoor falls in the previous year, and use of hormone replacement therapy (HRT). CONCLUSION: The authors conclude that self-report of hip, wrist, or upper arm fractures among Danish nurses is relatively accurate but varies by the site of fracture. False positive reports of fracture introduce only modest bias fracture risk estimates and tend to dilute the association between exposures and fracture.

Risk of low-energy hip, wrist, and upper arm fractures among current and previous users of hormone replacement therapy: The Danish Nurse Cohort Study.

OBJECTIVE: To examine the effect of oestrogen alone and in combination with progestin on the risk of low-energy, hip, wrist, and upper arm fractures. Additionally, to examine to what extent previous use, duration of use as well as recency of discontinuation of hormone replacement therapy (HRT) influences the fracture risk. DESIGN: Prospective cohort study. SETTING: The Danish Nurse Cohort Study PARTICIPANTS: 7082 female nurses aged 50-69, who completed a questionnaire on lifestyle and use of HRT in 1993. OUTCOME MEASURES: Self-reported low-energy, hip, wrist, and upper arm fractures between 1993--1999 obtained at a re-examination in 1999. RESULTS: Compared to never users, current users of HRT, either oestrogen alone or combined with progestin, had a lower risk of low-energy, hip, wrist, and upper arm fractures (hazard ratio 0.60, 0.39-0.93 and hazard ratio 0.44, 0.30-0.66, respectively). The protective effect of HRT appeared to be significantly restricted to users who used the therapy for 10 years or more (hazard ratio 0.27, 0.14-0.51). Women who previously used hormones experienced no protective effect on fracture risk regardless of duration of therapy and recency of discontinuation. CONCLUSION: Only long-term HRT (10 years or more) offers a protective effect against low energy, hip, wrist, and upper arm fractures. In women with risk factors or established osteoporosis, benefits and risks of this therapy should be balanced when considering its use as a first line treatment for prevention of these fractures.

No inverse association between fish consumption and risk of death from all-causes, and incidence of coronary heart disease in middle-aged, Danish adults.

This study investigate the relation between fish consumption, all-cause mortality, and incidence of coronary heart disease (CHD). A total of 4,513 men and 3,984 women aged 30-70 years, sampled randomly from the population in Copenhagen County, Denmark, with initially examination in 1982-1992 was followed until 2000 for all-cause mortality and until 1997 for first admission to hospital or death from CHD. Information on fish consumption was obtained from a self-administered food-frequency questionnaire. Cox proportional hazard analysis gave no evidence for an inverse association between fish consumption and all-cause mortality or incident CHD after adjustment for confounders. Among subjects with a priory-defined high risk of CHD there was a nonsignificant inverse relation between fish intake and CHD morbidity (Hazard Ratio 1.28 (0.92-1.80) for a consumption of fish of less than two times per month or less compared with once a week), but there was relatively few cases in this subgroup. These data provides no evidence for a protective effect of fish consumption on all-cause mortality or incident CHD in the population as a whole, but it cannot be excluded that frequent consumption of fish benefits those at high risk for CHD.

Incidence and characteristics of falls leading to hospital treatment: a one-year population surveillance study of the Danish population aged 45 years and over.

AIMS: The aim was to quantify and characterize the incidence of fall injury events among middle-aged and older adults who require acute medical attention at Danish hospitals. METHODS: A one-year population surveillance study was carried out, based on the Danish National Hospital Register (DNHR), which covers all somatic hospital discharges and accident and emergency (A&E) services at hospitals in Denmark. RESULTS: During 1996 a total of 81,121 fall injury events were treated at A&E departments or resulted in admission to a somatic hospital department among Danes aged 45 years and over. Up to age 50 years the incidence rates of injurious fall events requiring medical attention were similar in men and women. At age 50 years, the incidence rates in women exceeded the rates in men and remained 1.2-1.8 times higher thereafter. After age 70 years, the rates increased exponentially in both sexes: from 27.4 and 49.3 per 1,000 person-years in men and women, respectively, to peaks of 112.8 and 170.8 per 1,000 person-years, respectively, at age 85 years and over. The proportion of falls occurring indoors and in institutional settings increased with advancing age. Compared with men, women had higher rates of fall-related contusions, distortions and fractures at all ages. CONCLUSIONS: Fall-prevention programmes should be directed towards the population aged 70 years and over, in particular towards women and hazards in residential environments. Our finding of an increasing incidence of injurious fall events among women around the time of the menopause raises the hypothesis that loss of oestrogen production plays a role in the aetiology of falls in women.