Physical activity, sex steroid, and growth factor concentrations in pre- and post-menopausal women: a cross-sectional study within the EPIC cohort.

PURPOSE: Increased physical activity (PA) is associated with a reduced risk of several cancers. PA may reduce cancer risk by changing endogenous hormones levels, but relatively little research has focused on this topic. The purpose of this study was to elucidate the relation between PA and endogenous hormone concentrations. METHODS: A cross-sectional analysis of 798 pre- and 1,360 post-menopausal women included as controls in case-control studies on endogenous hormones (steroids, progesterone, sex-hormone-binding globulin (SHBG), and growth factors) levels, and cancer risk nested within European Prospective Investigation into Cancer and Nutrition cohort was performed. Multivariate regression analyses were performed to compare geometric mean levels of hormones and SHBG by categories of PA. RESULTS: In pre-menopausal women, active women had 19 % significantly lower concentrations of androstenedione, 14 % lower testosterone, and 20 % lower free testosterone than inactive women, while no differences were observed for estrogens, progesterone, SHBG, and growth factors. In post-menopausal women, active women had 18 % significantly lower estradiol and 20 % lower free estradiol concentrations than inactive women, while no differences were observed for the other hormones and SHBG. More vigorous forms of physical activity were associated with higher insulin-like growth factor-I concentrations. Adjustment for body mass index did not alter the associations. Overall, the percentage of variance in hormone concentrations explained by PA levels was <2 %. CONCLUSIONS: Our results support the hypothesis of an influence, although small in magnitude, of PA on sex hormone levels in blood, independent of body size.

Combined effects of weight loss and physical activity on all-cause mortality of overweight men and women.

OBJECTIVE: To estimate the excess deaths associated with weight loss in combination with leisure time physical activity among overweight or obese people. DESIGN: Prospective cohort study. SUBJECTS: In two consecutive examinations in 1976-1978 and 1981-1983, 11 135 people participated in the Copenhagen City Heart Study. Of these, 3078 overweight or obese participants lost weight or remained weight stable from 1976-1978 to 1981-1983, and were without pre-existing diagnosis of diabetes, stroke, ischaemic heart disease or cancer in 1981-1983. They were followed up until 2007 in the Danish Civil Registration System, with a <0.2% loss to follow-up only. MEASUREMENTS: The following measurements were taken: body mass index (BMI) and physical activity in 1976-1978 and 1981-1983 and hazard ratio (HR) of mortality during 53 976 person-years of follow-up. RESULTS: Of the initially overweight or obese subjects who either lost weight or remained weight stable, 2060 died. Overall, weight loss was associated with excess mortality when compared with weight stability. Weight loss was associated with a higher mortality among those who became physically inactive, compared with those who remained active while losing weight (men: HR 2.25, 95% confidence interval 1.31-3.84; women: 1.43, 1.07-1.91). However, losing weight while remaining physically active was still associated with excess mortality when compared with those who were weight stable and initially active (men: 1.72, 1.27-2.34; women: 1.57, 1.06-2.31). Among those who remained physically inactive, weight loss seemed associated with excess mortality when compared with weight loss among those who became active, although not statistically significant (men: 2.00, 0.94-4.29; women: 1.40, 0.82-2.39). Finally, weight loss among those who became physically active was not associated with excess mortality when compared with those who were weight stable and initially inactive (men: 1.12, 0.61-2.07; women: 1.19, 0.58-2.43). CONCLUSION: Weight loss among the overweight or obese seemed hazardous to survival. However, weight loss seemed less hazardous to survival among those who remained physically active or those who became active.

Combined influence of leisure-time physical activity and hip circumference on all-cause mortality.

UNLABELLED: Hip circumference has been shown to be inversely associated with mortality. Muscle atrophy in the gluteofemoral region may be a possible explanation and thus physical activity is likely to play an important role. OBJECTIVE: To estimate the combined effects of hip circumference and physical activity on mortality. DESIGN AND METHODS: From the Copenhagen City Heart Study, 3,358 men and 4,350 women aged 21 to 93 years without pre-existing diagnosis of diabetes, stroke, ischemic heart disease, or cancer in 1991-1994 and with complete information on the variables of interest were included in the analyses. The participants were followed to 2009 in the Danish Civil Registration System, with 1.3% loss to follow-up and 2,513 deaths. Hazard ratios (HR) were estimated for combinations of physical activity and hip circumference. RESULTS: Hip circumference was inversely associated with mortality irrespective of being physically active or not. However, being physically active seemed to counterbalance some of the adverse health effects of a small hip circumference; when comparing inactive to active, the excess mortality at the 25th percentile of hip circumference is 40% in men (HR = 1.40, 95% CI: 1.14-1.72) and 33% in women (HR = 1.33, CI: 1.10-1.62). These associations were observed after adjustment for waist circumference and weight change in the 6 months before the examination. CONCLUSION: Less effects of physical activity were found in individuals with greater hip circumferences. A small hip circumference appears hazardous to survival. However, being physically active may counterbalance some of the hazardous effects of a small hip circumference.