The association between physical activity and forearm bone mineral density in healthy premenopausal women

A 15-year follow-up study of hip bone mineral density and associations with leisure time physical activity. The Tromsø Study 2001–2016

Aims

The aim was to investigate the long-term association between leisure time physical activity and hip areal bone mineral density (aBMD), in addition to change in hip aBMD over time, in 32–86 years old women and men.

Methods

Data were retrieved from the 2001, 2007–2008, and 2015–2016 surveys of the Tromsø Study, a longitudinal population study in Norway. Leisure time physical activity was assessed by the four-level Saltin-Grimby Physical Activity Level Scale which refers to physical exertion in the past twelve months. Hip aBMD was assessed by Dual-Energy X-ray Absorptiometry. Linear Mixed Model analysis was used to examine long-term associations between physical activity and hip aBMD (n = 6324). In addition, the annual change in hip aBMD was analyzed in a subsample of 3199 participants.

Results

Physical activity was significantly and positively associated with total hip aBMD in the overall cohort (p<0.005). Participants who reported vigorous activity had 28.20 mg/cm2 higher aBMD than those who were inactive (95% CI 14.71; 41.69, controlled for confounders), and even light physical activity was associated with higher aBMD than inactivity (8.32 mg/cm2, 95% CI 4.89; 11.76). Associations between physical activity and femoral neck aBMD yielded similar results. Hip aBMD decreased with age in both sexes, although more prominently in women. From 2001 to 2007–2008, aBMD changed by –5.76 mg/cm2 per year (95% CI –6.08; –5.44) in women, and –2.31 mg/cm2 (95% CI –2.69; –1.93), in men. From 2007–2008 to 2015–2016, the change was –4.45 mg/cm2 per year (95% CI –4.84; –4.06) in women, and –1.45 mg/cm2 (95% CI –1.92; –0.98) in men.

Conclusions

In this cohort of adult men and women, physical activity levels were positively associated with hip aBMD in a dose-response relationship. Hip aBMD decreased with age, although more pronounced in women than men.

Bone mineral density and risk of cardiovascular disease in men and women: the HUNT study

The association between bone mineral density (BMD) and cardiovascular disease (CVD) is not fully understood. We evaluated BMD as a risk factor for cardiovascular disease and specifically atrial fibrillation (AF), acute myocardial infarction (AMI), ischemic (IS) and hemorrhagic stroke (HS) and heart failure (HF) in men and women. This prospective population cohort utilized data on 22 857 adults from the second and third surveys of the HUNT Study in Norway free from CVD at baseline. BMD was measured using single and dual-energy X-ray absorptiometry in the non-dominant distal forearm and T-score was calculated. Hazard ratios (HR) and 95% confidence intervals (CI) were calculated from adjusted cox proportional hazards models. The analyses were sex-stratified, and models were adjusted for age, age-squared, BMI, physical activity, smoking status, alcohol use, and education level. Additionally, in women, we adjusted for estrogen use and postmenopause. During a mean follow-up of 13.6 ± 5.7 years, 2 928 individuals (12.8%) developed fatal or non-fatal CVD, 1 020 AF (4.5%), 1 172 AMI (5.1%), 1 389 IS (6.1%), 264 HS (1.1%), and 464 HF (2.0%). For every 1 unit decrease in BMD T-score the HR for any CVD was 1.01 (95% CI 0.98 to 1.04) in women and 0.99 (95% CI 0.94 to 1.03) in men. Point estimates for the four cardiovascular outcomes ranged from slightly protective (HR 0.95 for AF in men) to slightly deleterious (HR 1.12 for HS in men). We found no evidence of association of lower distal forearm BMD with CVD, AF, AMI, IS, HS, and HF.

Gender-specific associations between leisure-time physical activity and symptoms of anxiety: the HUNT study

PURPOSE

The underlying goal of the study was to examine gender-specific effects of leisure-time physical activity on the development of symptoms of anxiety.

METHODS

The second wave of a prospective cohort survey (HUNT 2) was conducted during 1995-1997 in the county of Nord-Trøndelag, Norway, with a follow-up in 2006-2008 (HUNT 3). The sample consisted of 12,796 women and 11,195 men with an age range of 19-85 years. A binomial model with a log-link function and generalized linear model analysis with gamma distribution was used to assess the association between physical activity and anxiety symptoms (Hospital Anxiety and Depression Scale anxiety subscale, HADS-A).

RESULTS

A total of 1,211 (9.5 %) women and 650 (5.8 %) men developed HADS-defined anxiety (≥8 on the HADS-A scale). Men who scored in the middle tertile of the calculated physical activity index developed significantly fewer cases of HADS-defined anxiety compared with men in the lowest tertile (p < 0.05). In the gamma regression analysis for women, having higher scores on the moderate-high physical activity was associated with fewer symptoms of anxiety (p < 0.01).

CONCLUSIONS

Women developed almost twice as many cases of HADS-defined anxiety compared to men. Significant associations were found between general leisure-time physical activity and anxiety symptoms among women and men, but the true effect is likely to be different from the observed associations due to several threats to the internal validity in the study.

Physical activity, body mass index and bone mineral density-associations in a prospective population-based cohort of women and men: the Canadian Multicentre Osteoporosis Study (CaMos)

BACKGROUND

Physical activity (PA) is an important modifiable risk factor for both bone mineral density (BMD) and body mass index (BMI). However, BMI is itself strongly predictive of BMD. Our aim was to determine the association between PA and BMD, with consideration of BMI as a potential mediating factor.

METHODS

The Canadian Multicentre Osteoporosis Study (CaMos) is a population-based prospective cohort study of Canadian women and men. PA was determined from interviewer-administered questionnaires at baseline and Year 5 and summarized as daily energy expenditure in total metabolic equivalents of the task multiplied by minutes/day (MET*m/d). Height, weight, and total hip and lumbar spine BMD were measured at baseline and Year 5. General linear models assessed relationships between PA and BMD, both cross-sectionally (baseline PA with baseline BMD) and longitudinally (average PA and change in PA with change in BMD). BMI was considered as a mediating factor. Potential confounders included age, center, education, caffeine intake, alcohol exposure, smoking history, history of weight-cycling, age at menarche, past use of oral contraceptives, history of >3 months missed menstruation, menopausal status, and antiresorptive use, as relevant.

RESULTS

The study included 2855 men and 6442 women. PA was inversely associated with BMI at baseline, and an increase in PA between baseline and Year 5 was associated with a decrease in BMI, with 0.41 (95% CI: 0.22, 0.60) kg/m(2) loss per 1000 MET*m/d increase (in men) and 0.40 (95% CI: 0.23, 0.57) kg/m(2) loss per 1000 MET*m/d increase (in women). BMI was strongly associated with BMD, both cross-sectionally and longitudinally. However, increased PA was associated with a small increase in total hip BMD, 0.004 (95% CI: 0.000-0.008) g/cm(2) per 1000 MET*m/d (in men) and 0.003 (95% CI: 0.000-0.007) g/cm(2) per 1000 MET*m/d (in women). Average PA was associated with an increase in lumbar spine BMD in women, but not in men; it was not associated with change in total hip BMD in either sex.

CONCLUSION

Increased PA is associated with an increase in BMD and a concomitant decrease in BMI. These findings suggest that population-level interventions to increase PA would favorably impact bone and other health outcomes.

Physical activity and fertility in women: the North-Trøndelag Health Study

BACKGROUND

Changes in the state of energy balance owing to changes in physical activity may affect the reproductive system. We evaluated the association between physical activity (PA) and fertility and parity in healthy women.

METHODS

A population-based health survey (HUNT 1) was conducted during 1984-1986 in Nord-Trøndelag county, Norway, with follow-up from 1995 to 1997 (HUNT 2). The study included 3887 women, <45 years old in HUNT 2. PA was assessed by baseline questionnaire, and fertility and parity by questionnaire at follow-up. Data focused on overall occurrence of infertility in the population (without biological confirmation).

RESULTS

Increased frequency, duration and intensity of PA were associated with increased subfertility, and frequency of PA was associated with voluntary childlessness (P < 0.01). After adjusting for age, parity, smoking, and marital status, women who were active on most days were 3.2 times more likely to have fertility problems than inactive women. Exercising to exhaustion was associated with 2.3 times the odds of fertility problems versus low intensity. Women with highest intensity of PA at baseline had the lowest frequency of continuing nulliparity and highest frequency of having three or more children during follow-up (P < 0.05). Sensitivity analysis including body mass index as confounder did not alter the results. No associations were found between lower activity levels and fertility or parity.

CONCLUSION

Increased risk of infertility was only found for the small group of women reporting the highest levels of intensity and frequency of PA. Awareness of the possible risks of infertility should be highlighted among non-athletic women who exercise vigorously.

[The relationship between lifetime sports activity measured with MET and peak strain score and bone measurement in college-aged women]

PURPOSE

The aim of this study was to compare the relation between differently measured sports activities (metabolic equivalent [MET] and peak strain score) and distal radius bone mineral density in college-aged women.

METHODS

Lifetime sports activity was scored in two different ways: 1) a sports activity score by multiplying the intensity (METs) and duration and 2) a sports activity score by adding up physical strain scores based on the ground reaction force of each sports activities. Bone mineral density was measured using dual energy x-ray densitometry (DTX-200) in the distal radius site.

RESULTS

In stepwise multiple regression analysis, body weight and sports activities during the college period were significant positive predictors for distal radius bone mineral density. The explained variance of sports activity measured with a peak strain score (8.8%) for distal radius bone mineral density was higher than one measured with the MET score (3.3%).

CONCLUSION

It can be concluded that sports activity scores based on MET and peak strain scores during college are very important for determining the bone mineral density in the distal radius site in women under 30.

Health, Medical Risk Factors, and Bicycle Use in Everyday Life in the Over-50 Population

Few middle-aged and elderly people get enough exercise from sports or leisure-time physical activity. Therefore, the impact of everyday physical activity on health is a matter of interest. The main objective of this study was to establish whether bicycle use in everyday life is positively associated with health. A sample of 982 randomly selected men and 1,020 women age 50–70 were asked in a computer-assisted telephone interview to provide information including a self-assessment of their health and physical activity. Self-assessed health correlates positively with bicycle use in everyday life (OR = 1.257; 95% CI: 1.031–1.532). Likewise, people who regularly cycle for transport are less likely to have medical risk factors (OR = 0.794; 95% CI: 0.652–0.967). This negative correlation is not diminished when sporting activity is controlled for. This indicates that positive effects of physical activity on risk factors can be also achieved solely by integrating more physical activity into routine everyday life.