Physical activity and the risk of hip fracture in the elderly: a prospective cohort study

Physical activity has been inversely associated with the risk of hip fracture, however, few studies have been conducted on the contributions from different domains of physical activity. This study was performed to investigate the association between daily household activities, leisure time physical activity, work-related physical activity and total physical activity during a 24-h period, and the risk of hip fracture. In the Swedish National March Cohort we followed 23,881 men and women aged of 50 and over from 1997 until 2010. Information on domain-specific physical activity was collected at baseline using a questionnaire. We fitted separate multivariable adjusted Cox proportional hazard models to each domain to obtain hazard ratios (HRs) with 95% confidence intervals (CIs). Each model was mutually adjusted for the other domains of physical activity. During a mean follow-up period of 12.2 years we identified 824 incidents of hip fracture. Subjects who spent less than 1 h per week engaged in daily household activities had an 85% higher risk of hip fracture than subjects spending ≥6 h per week carrying out daily household activities (HR 1.85; 95% CI 1.01–3.38). Subjects engaged in leisure time physical activities for >3.1 MET-h/day had a 24% lower risk of hip fracture (HR 0.76; 95% CI 0.59–0.98) than subjects spending <1.1 MET-h/day performing such activities. No association was found between hip fracture and work-related or total physical activity. We conclude that daily household activities and leisure time physical activity may independently decrease the risk of hip fracture in those aged 50 and over.     

Leisure-time physical activity levels and changes in relation to risk of hip fracture in men and women.

The authors prospectively studied the effect of leisure-time physical activity level on hip fracture risk along with the influence of within-subject changes in activity levels, while taking possible confounding by other health behaviors and poor health into account. Analyses were based on pooled data from three population studies conducted in Copenhagen, Denmark. Among 13,183 women and 17,045 men, 1,121 first hip fractures were identified during follow-up. In comparison with being sedentary, the relative risk (RR) of hip fracture associated with being moderately physically active 2-4 hours per week was 0.72 (95% confidence interval (CI): 0.59, 0.89) in women and 0.75 (95% CI: 0.55, 1.03) in men after adjustment for confounders. Being in the most active leisure activity category did not decrease the risk of hip fracture further. Adjustment for poor health affected the risk estimates only modestly. Subjects who, during follow-up, reduced their physical activity level from the highest or the intermediate activity level to a sedentary level had a higher risk of hip fracture than did those who remained moderately physically active at the intermediate level (multivariate adjusted RR = 2.19, 95% CI: 1.00, 4.84 and RR = 1.89, 95% CI: 1.21, 2.95, for reduction from the highest and intermediate levels, respectively). There was no evidence of a fracture-protective effect from increasing physical activity. In conclusion, moderate levels of physical activity appear to provide protection against later hip fracture. Decline in the physical activity level over time is an important risk factor for hip fracture.     

Occupational and leisure time physical activity and the risk of nonfatal acute myocardial infarction in Italy

PURPOSE: Physical activity has long been related to a reduced risk of coronary heart disease (CHD), including acute myocardial infarction (AMI). However, the quantitative estimates of the possible protective role of physical activity appear to vary across studies and populations. METHODS: A case-control study conducted in Italy between 1995 and 1999, including 507 incident cases below 79 years (378 men, 129 women) with a first episode of AMI, and 478 controls (297 men, 181 women) admitted to hospitals for acute conditions. RESULTS: Compared with the lowest level of occupational physical activity, the multivariate odds ratios (OR) of AMI for the highest level were 0.61 (95% confidence interval [CI], 0.38-0.97) at age 15 to 19 years, 0.57 (95% CI, 0.34-0.95) at age 30 to 39 years, and 0.51 (95% CI, 0.29-0.90) at age 50 to 59 years. The corresponding values for leisure time activity were 0.54 (95% CI, 0.38-0.77), 0.86 (95% CI, 0.57-1.30), and 1.00 (95% CI, 0.57-1.74), respectively. The association was consistent across strata of age, sex, education, smoking, and other selected covariates. CONCLUSIONS: The attributable risk for low occupational exercise at age 30 to 39 years was over 10%, indicating the scope for further intervention on this modifiable risk factor in this Italian population, particularly in consideration of the public health importance of CHD.     

Leisure time physical activity and risk of non-vertebral fracture in men and women aged 55?years and older: the Troms? Study

Our aim was to examine associations between leisure time physical activity and risk of non-vertebral fractures in men and women aged ≥55 years, with focus on the anatomical fracture location. Self-reported physical activity was registered in 3,450 men and 4,072 women aged 55-97 years at baseline in the Troms? Study, Norway, in 1994-1995. Non-vertebral fractures were registered through December 31, 2009. During 75,546 person-years at risk, 1,693 non-vertebral fractures were identified. Risk of any non-vertebral fracture decreased with increasing physical activity level in men (P (trend) = 0.006) and non-significantly in women (P (trend) = 0.15), after adjustment for age, body mass index, height, smoking, and previous fracture. The reduced fracture risk was due to a reduced risk in the weight-bearing skeleton, particular at the hip, whereas risk of fracture in the non-weight-bearing skeleton was not related to physical activity. At weight-bearing sites, an inverse relationship between physical activity and fracture risk was present in both sexes (P (trend) ≤ 0.013). Compared with sedentary subjects, the most active men and women had respectively 37% (HR = 0.63, 95% CI: 0.45, 0.88) and 23% (HR = 0.77, 95% CI: 0.62, 0.95) reduced fracture risk in the weight-bearing skeleton. Physical activity is associated with reduced fracture risk at weight-bearing sites, with no associations at non-weight-bearing sites, in both sexes. Habitual physical activity is an important amendable approach to prevent hip fracture.     

Reduced risk of hip fracture in women with endometrial cancer.

The effect of excessive endogenous oestrogens on the risk of hip fracture was investigated in a population-based cohort of 2111 women with endometrial carcinoma who were followed up from age 50 years regarding the occurrence of a first hip fracture. Overall, 77 cases of hip fracture were observed, as against 120.8 expected, which meant a significantly reduced relative risk, standardized incidence ratio (SIR) = 0.6, 95% confidence interval (CI): 0.5-0.8. This possible protective effect was significant for cervical fractures, SIR = 0.6 (95% CI: 0.4-0.8), but not for trochanteric, SIR = 0.8 (95% CI: 0.5-1.1). Age at endometrial cancer diagnosis was not a determinant of the risk of hip fracture. A lowered relative risk was present regardless of age at diagnosis and persisted during the entire follow-up period and into advanced ages. A case-control analysis within the cohort, and based on medical record data, indicated that a higher weight might be associated with a greater protective effect, as compared with a lower weight. Exposure to exogenous oestrogens was infrequent and could not have explained the present results. We conclude that persistent influence of oestrogens, notably of endogenous origin, can reduce the risk of hip fractures, and that this protective effect may be long-lasting and extend to advanced ages.     

Body size and hip fracture risk. Swedish Hip Fracture Study Group

The objective of this population-based case-control study was to determine the independent association between height, weight at different ages and adult weight change on hip fracture risk, and the joint effects of these factors. The study base comprised postmenopausal women 50-81 years of age who resided in six counties in Sweden during the period October 1993 to February 1995. The study included 1,327 cases with an incident hip fracture and 3,262 randomly selected controls. We obtained information on body measures and other factors possibly related to hip fracture through mailed questionnaires and telephone interviews. Height and weight change were dominant risk factors. Tall women (> or = 169 cm) had an odds ratio of 3.16 (95% confidence interval = 2.47-4.05) compared with women shorter than 159 cm. Weight gain during adult life was strongly protective: compared with those with moderate weight change (-3 to 3 kg), those with substantial weight gain (> or =12 kg) had a markedly decreased risk of hip fracture (odds ratio = 0.35; 95% confidence interval = 0.27-0.45), whereas weight loss was associated with an increased risk. Weight change retained important effects among all subjects, even after controlling for current weight and weight at age 18. In contrast, among women who gained weight, the separate effects of current weight and weight at age 18 were small or absent. Among women who lost weight, both current weight and weight at age 18 had effects that remained after controlling for weight change. Adult weight change and height are dominant body size risk factors for hip fracture. Weight loss vs weight changes demarcates different patterns of hip fracture risk.     

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.     

Physical activity and self-reported, physician-diagnosed osteoarthritis: is physical activity a risk factor?

This prospective study evaluated regular physical activity and self-reported physician-diagnosed osteoarthritis of the knee and/or hip joints among 16,961 people, ages 20-87, examined at the Cooper Clinic between 1970 and 1995. Among those aged 50 years and older, osteoarthritis incidence was higher among women (7.0 per 1000 person-years) than among men (4.9 per 1000 person-years, P = 0.001), while among those under 50 years of age, osteoarthritis incidence was similar between men (2.6) and women (2.7). High levels of physical activity (running 20 or more miles per week) were associated with osteoarthritis among men under age 50 after controlling for body mass index, smoking, and use of alcohol or caffeine (hazard ratio = 2.4, 95% CI: 1.5, 3.9), while no relationship was suggested among women or older men. These findings support the conclusion that high levels of physical activity may be a risk factor for symptomatic osteoarthritis among men under age 50.     

Low Physical Activity Is a Predictor of Thinness and Low Self-rated Health: Gender Differences in a Swedish Cohort

PurposeTo examine the relationship between leisure time physical activity in 15-year-old students, and weight status and self-rated health 3 years later.MethodsData were used from two follow-up waves, one in 2002 (grade 9, age 15 years) and one in 2005 (grade 12, age 18 years) of a cohort of approximately 2,500 adolescents. Adolescents reported height and weight, health behaviors, and self-rated health by a questionnaire at both occasions. Age and gender-specific body mass index cut-off points for thinness, overweight, and obesity were used to assess weight status. Logistic regression analyses were performed with weight status and self-rated health as the outcomes and level of leisure time physical activity as the independent variable. Adjustments were made for parental years of education, student's current smoking habits, and baseline body mass index.ResultsAs compared with students who were active for more than 4 hours per week during leisure time, being active 2–4 hours (odds ratio [OR]: 4.15, confidence interval [CI]: 1.62–10.60) and <2 hours (OR: 3.92, CI: 1.30–11.78) predicted thinness in boys. In girls, the risk was smaller and became significant at <2 hours per week (OR: 2.57, CI: 1.38–4.77). Overweight or obesity was not significantly predicted by physical activity. A significant risk of low self-rated health was found at follow-up in boys active for <4 hours per week compared with those active for >4 hours per week.ConclusionPhysical activity is important to maintain a healthy body weight and for future self-rated health in boys.     

Physical activity and stroke. A meta-analysis of observational data

BACKGROUND: Based on studies published so far, the protective effect of physical activity on stroke remains controversial. Specifically, there is a lack of insight into the sources of heterogeneity between studies. METHODS: Meta-analysis of observational studies was used to quantify the relationship between physical activity and stroke and to explore sources of heterogeneity. In total, 31 relevant publications were included. Risk estimates and study characteristics were extracted from original studies and converted to a standard format for use in a central database. RESULTS: Moderately intense physical activity compared with inactivity, showed a protective effect on total stroke for both occupational (RR = 0.64, 95% CI: 0.48-0.87) and leisure time physical activity (RR = 0.85, 95% CI: 0.78-0.93). High level occupational physical activity protected against ischaemic stroke compared with both moderate (RR = 0.77, 95% CI: 0.60-0.98) and inactive occupational levels (RR = 0.57, 95% CI: 0.43-0.77). High level compared with low level leisure time physical activity protected against total stroke (RR = 0.78, 95% CI: 0.71-0.85), haemorrhagic stroke (RR = 0.74, 95% CI: 0.57-0.96) as well as ischaemic stroke (RR = 0.79, 95% CI: 0.69-0.91). Studies conducted in Europe showed a stronger protective effect (RR = 0.47, 95% CI: 0.33-0.66) than studies conducted in the US (RR = 0.82, 95% CI: 0.75-0.90). CONCLUSIONS: Lack of physical activity is a modifiable risk factor for both total stroke and stroke subtypes. Moderately intense physical activity is sufficient to achieve risk reduction.     

Leisure-time physical activity among pregnant women in the US

Few population-based data exist that describe leisure-time physical activity among pregnant women. The purpose of this study was to characterise the prevalence of leisure activity and to examine characteristics associated with participation in leisure activity during pregnancy. Using data collected from the year 2000 Behavioral Risk Factor Surveillance System, information on leisure activity was collected during telephone interviews from 1979 pregnant women and 44,657 non-pregnant women 18-44 years of age, representative of the US population. The prevalence of any leisure activity in the past month was 65.6%, 95% confidence interval [95% CI] 62.0, 69.1, among pregnant women and 73.1% [95% CI 72.4, 73.9] among non-pregnant women. The prevalence of recommended activity was also lower among pregnant women than non-pregnant women (15.8% vs. 26.1%). The most common leisure activity for pregnant women was walking, followed by activities such as swimming laps, weight lifting, gardening, and aerobics. Among pregnant women, any leisure activity was significantly higher for those with higher education, younger age, and excellent or very good health than for those with fair or poor health. Pregnant women reported less leisure activity than non-pregnant women of the same age. Studies to understand the enablers and barriers to participating in leisure activity during pregnancy are needed.     

Physical activity and bone mineral density in Italian middle-aged women

Osteoporosis is a major health issue in postmenopausal women on account of the association between low bone mineral density and fractures. A role of physical activity in the prevention and treatment of low bone mineral density is possible but still unclear. The relationship between low spine bone mineral density measured by means of dual photon absorptiometry at lumbar spines, and levels of past and recent physical activity has been assessed by means of a population-based screening study carried out on 1373 women (age 40–64 years) in the North-East of Italy. Physical activity at work and in leisure time was investigated for three specific periods of life: at age 12, between 15 and 19 years (during bone formative years), and in the recent years prior to the interview (30–39 or 50–59 years). Data were analysed comparing low versus high bone mineral density tertile (i.e., 458 and 461 women, respectively), after controlling for other known contributory factors in the development of osteoporosis. A positive association emerged with leisure time physical activity, with significant trends at age 15–19 (odds ratio (OR) for low versus high tertile of leisure time activity: 1.4, 95% confidence interval (CI): 0.8–2.4) and at most recent age (OR: 1.7, 95% CI: 1.1–2.6). Risk trends with occupational physical activity were less clear and non-statistically significant. The present Southern European cross-sectional study lends further support to the possibility that past and recent physical activity helps increasing bone mineral density in middle-aged women. Although the most beneficial type and intensity level of exercise has yet to be determined, the present results provide further evidence that participation in even moderate exercise programs should be encouraged.     

The association between leisure time physical activity and coronary heart disease among men with different physical work demands: a prospective cohort study

The interplay of occupational and leisure time physical activity (LTPA) in affecting cardiovascular health is subject to debate. This study aimed to examine the independent and interacting associations of leisure time and occupational physical activity (OPA) with the incidence of coronary events within the BELSTRESS cohort. The study included 14,337 middle-aged men free from coronary heart disease at baseline. Standardized questionnaires and clinical examinations were used to assess socio-demographic factors, level of physical activity, job strain and classical coronary risk factors. The incidence of clinical coronary events was monitored during a mean follow-up time of 3.15 years. Results demonstrated overall a beneficial relation of LTPA and an adverse relation of physical work demands with cardiovascular health. However, an interaction effect between both physical activity types was observed, showing that men with high physical job demands who also engaged in physical activity during leisure time had an almost four times increased incidence of coronary events after adjusting for socio-demographic and classical coronary risk factors (HR 3.82; 95 % CI 1.41–10.36). Stratified analyses revealed that moderate to high physical activity during leisure time was associated with a 60 % reduced incidence rate of coronary events in men with low OPA (age adjusted HR 0.40; 95 % CI 0.21–0.76), while this protective association was not observed in workers being exposed to high physical work demands (age adjusted HR 1.67; 95 % CI 0.63–4.48). These findings suggest that recommendations regarding LTPA should be tailored according to the level of occupational physical activity.     

Peer Reviewed: Smoking Status as a Predictor of Hip Fracture Risk in Postmenopausal Women of Northwest Texas

Introduction

The purpose of this study was to determine the effect of cigarette smoking on the risk of hip fracture for postmenopausal women living in rural and urban areas of Northwest Texas.

Methods

Using an unmatched case-control design, we compared postmenopausal women who had recently experienced osteoporotic hip fracture with women who had not. Both study groups completed a questionnaire on demographic, clinical, and behavioral risk factors for osteoporotic hip fracture. We categorized smoking status as never smoked, former smoker, and current smoker. Covariates included age, weight, age at menopause, physical activity, estrogen replacement, calcium supplementation, and rurality. We used univariate and multivariate logistic regressions to test the associations between hip fracture and the independent variables of interest.

Results

We found an increased risk of hip fracture for former smokers (adjusted odds ratio [OR], 2.27; 95% confidence interval [CI], 1.22–4.21) and current smokers (adjusted OR, 3.72; 95% CI, 1.59–8.70). Residence in a rural county (population <100,000) also was associated with increased risk (adjusted OR, 2.71; 95% CI, 1.48–4.95).

Conclusion

Former and current smoking increased the risk of hip fracture in this population of postmenopausal women.     

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.     

Leisure time and occupational physical activity: risk of death from ischemic heart disease

The relation of leisure time and occupational physical activity to the risk of death from ischemic heart disease was investigated in a cohort of 15,088 persons aged 30-59 years who had no history of cardiovascular disease or other condition which hindered physical activity. Two population samples were randomly chosen from eastern Finland. During a six-year follow-up, persons who were sedentary in leisure time (relative risk = 1.3, 95% confidence interval (CI) = 1.1-1.6) or at work (relative risk = 1.3, 95% CI = 1.1-1.6) had an excess risk of ischemic heart disease death when adjusted for age, health status, family history, and body mass index in multivariate logistic models. Adjustment for years of education, social network participation, cigarette consumption, serum cholesterol level, and blood pressure level weakened the residual association of low leisure time physical activity with the risk of ischemic heart disease death (relative risk = 1.2, 95% CI = 1.0-1.5), whereas the association for low occupational physical activity remained unchanged. The lack of leisure time physical activity and a sedentary occupation are associated with an increased risk of ischemic heart disease death, and the excess risk due to lack of leisure time physical activity is, in part, accounted for by other ischemic heart disease risk factors.     

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.     

Preference for wine is associated with lower hip fracture incidence in post-menopausal women

Background

Past studies of relationships between alcohol and hip fracture have generally focused on total alcohol consumed and not type of alcohol. Different types of alcohol consist of varying components which may affect risk of hip fracture differentially. This study seeks to examine the relationship between alcohol consumption, with a focus on type of alcohol consumed (e.g. beer, wine, or hard liquor) and hip fracture risk in post-menopausal women.

Methods

The longitudinal cohort consisted of U.S. post-menopausal women aged 50–79 years enrolled between 1993–1998 in the Women’s Health Initiative Clinical Trials and Observational Study (N=115,655).

Results

Women were categorized as non-drinkers, past drinkers, infrequent drinkers and drinkers by preference of alcohol type (i.e. those who preferred wine, beer, hard liquor, or who had no strong preference). Mean alcohol consumption among current drinkers was 3.3 servings per week; this was similar among those who preferred wine, beer and liquor. After adjustment for potential confounders, alcohol preference was strongly correlated with hip fracture risk (p = 0.0167); in particular, women who preferred wine were at lower risk than non-drinkers (OR=0.78; 95% CI 0.64-0.95), past drinkers (OR=0.85; 95% CI 0.72-1.00), infrequent drinkers (OR=0.73; 95% CI 0.61-0.88), hard liquor drinkers (OR=0.87; 95% CI 0.71-1.06), beer drinkers (OR=0.72; 95% CI 0.55-0.95) and those with no strong preference (OR=0.89; 95% CI 0.89; 95% CI 0.73-1.10).

Conclusions

Preference of alcohol type was associated with hip fracture; women who preferentially consumed wine had a lower risk of hip fracture compared to non-drinkers, past drinkers, and those with other alcohol preferences.

     

Hormone replacement therapy and hip fracture risk: effect modification by tobacco smoking, alcohol intake, physical activity, and body mass index

The authors prospectively studied the overall effect of hormone replacement therapy (HRT) on hip fracture risk and the effect modification by behavioral habits and body mass index. A total of 6,159 postmenopausal women from the Copenhagen Center for Prospective Population Studies, Copenhagen, Denmark, with initial examination in 1976-1978 were followed until 1993. During follow-up 363 hip fractures were identified. Women who reported current use of HRT had a lower risk of hip fracture as compared with women who were nonusers (relative risk (RR) = 0.71; 95 percent confidence interval (CI): 0.50, 1.01). Use of HRT was associated with a lower risk of hip fracture in former (RR = 0.55; 95 percent CI: 0.22, 1.37) and current (RR = 0.61; 95 percent CI: 0.38, 0.99) smokers but not in never smokers (RR = 1.10; 95 percent CI: 0.60, 2.03). HRT was also associated with lower risk of hip fracture among alcohol drinkers (RR = 0.36; 95 percent CI: 0.14, 0.90) and among sedentary women (RR = 0.42; 95 percent CI: 0.18, 0.98) but not among nondrinkers (RR = 0.99; 95 percent CI: 0.61, 1.61) and physically active women (RR = 0.92; 95 percent CI: 0.42, 2.04). There was no evidence of interaction between use of HRT and body mass index. In conclusion, the protective effect of HRT on hip fracture appears to be strongest in women who ever smoked, in women who drink alcohol, and in women who are sedentary. The results suggest that history of behavioral habits offers important information concerning the probable degree of protection against hip fracture afforded by HRT.     

Early childhood television viewing predicts explosive leg strength and waist circumference by middle childhood

Background

The aim of this study was to explore long-term predictors of leisure time physical activity in the general population.

Methods

This study comprised 718 men and women who participated in the national Mini-Finland Health Survey from 1978?C1980 and were re-examined in 2001. Participants were aged 30?C80 at baseline. Measurements included interviews, health examinations, and self-administered questionnaires, with information on socioeconomic position, occupational and leisure time physical activity, physical fitness, body mass index, smoking, alcohol consumption, and physical functional capacity. Analyses included persons who were working and had no limitations in functional capacity at baseline.

Results

The strongest predictor of being physically active at the follow-up was participation in physical activity at baseline, with an OR 13.82 (95%CI 5.50-34.70) for 3 or more types of regular activity, OR 2.33 (95%CI 1.22-4.47) for 1?C2 types of regular activity, and OR 3.26 (95%CI 2.07-5.15) for irregular activity, as compared to no activity. Other determinants for being physically active were moving upwards in occupational status, a high level of baseline occupational physical activity and remaining healthy weight during the follow-up.

Conclusions

To prevent physical inactivity among older adults, it is important to promote physical activity already in young adulthood and in middle age and to emphasize the importance of participating in many types of physical activity.