Dorthe Stensvold

Even low level of physical activity is associated with reduced mortality among people with metabolic syndrome, a population based study (the HUNT 2 study, Norway)

BackgroundLow levels of physical activity may increase the risk of developing metabolic syndrome, a cluster of metabolic factors that are associated with the risk of premature death. It has been suggested that physical activity may reduce the impact of factors associated with metabolic syndrome, but it is not known whether physical activity may reduce mortality in people with metabolic syndrome.MethodsIn a prospective study of 50,339 people, 13,449 had metabolic syndrome at baseline and were followed up for ten years to assess cause-specific mortality. The population was divided into two age groups: those younger than 65 years of age and those older than age 65. Information on their physical activity levels was collected at baseline.ResultsMetabolic syndrome was associated with higher mortality from all causes (hazard ratio (HR) 1.35, 95% confidence interval (95% CI) 1.20 to 1.52) and from cardiovascular causes (HR 1.78, 95% CI 1.39 to 2.29) in people younger than 65 years old than among other populations. In older people, there was no overall association of metabolic syndrome with mortality. People with metabolic syndrome who reported high levels of physical activity at baseline were at a reduced risk of death from all causes compared to those who reported no physical activity, both in the younger age group (HR 0.52, 95% CI 0.37 to 0.73) and in the older age group (HR 0.59, 95% CI 0.47 to 0.74).ConclusionAmong people with metabolic syndrome, physical activity was associated with reduced mortality from all causes and from cardiovascular causes. Compared to inactivity, even low levels of physical activity were associated with reduced mortality.

Effect of exercise training on inflammation status among people with metabolic syndrome.

BACKGROUND Metabolic syndrome is associated with chronic low-grade inflammation, a condition thought to play a key role in the pathogenesis of the syndrome. Among a number of proinflammatory cytokines, interleukin-18 (IL-18) seems to be the best marker for inflammation among people with metabolic syndrome. The aim of this study was to examine the effect of aerobic training versus strength training on circulating IL-18 and other proinflammatory markers in people with metabolic syndrome. METHODS Thirty-one inactive men and women with metabolic syndrome were randomized to either high-intensity aerobic interval training (AIT, n=11), strength training (ST, n=10), or a control group (n=10). Exercise training was carried out three times per week for 12 weeks. Serum insulin, high-sensitivity C-reactive protein (hsCRP), IL-18, IL-6, and tumor necrosis factor-α (TNF-α) were measured before and after the intervention. RESULTS Serum IL-18 was reduced by 43% after AIT (P<0.001). Although there was no change in TNF-α from baseline after AIT, the levels were lower compared to the ST (P=0.032) and control groups (P=0.039) after the intervention. Total body fat was reduced after AIT (from 33.9 ± 7.3% to 32.2 ± 7.9%, P<0.001) and ST (from 31.2 ± 3.9% to 29.7 ± 3.4%, P=0.025). There were no changes in serum IL-6, insulin, or hsCRP within or between the groups. CONCLUSION Both ST and AIT reduced fat mass. However, only the latter intervention was associated with a more favorable inflammatory status among people with metabolic syndrome. CLINICAL TRIAL REGISTRATION INFORMATION http://clinicaltrials.gov/show/NCT00986024/ .

Effect of moderate- and high-intensity acute exercise on appetite in obese individuals.

PURPOSE The effect of acute exercise, and exercise intensity, on appetite control in obese individuals requires further study. The aim of this study was to compare the effects of acute isocaloric bouts (250 kcal) of high-intensity intermittent cycling (HIIC) and moderate-intensity continuous cycling (MICC) or short-duration HIIC (S-HIIC) (125 kcal) and a resting control condition on the appetite hormone responses, subjective feelings of appetite, energy intake (EI), and food reward in overweight/obese individuals. METHODS This study is a randomized crossover study on 12 overweight/obese volunteers. Participants were assigned to the control, MICC, HIIC, and S-HIIC conditions, 1 wk apart, in a counterbalanced order. Exercise was performed 1 h after a standard breakfast. An ad libitum test lunch was served 3 h after breakfast. Fasting/postprandial plasma samples of insulin, acylated ghrelin, polypeptide YY3-36, and glucagon-like peptide 1 and subjective feelings of appetite were measured every 30 min for 3 h. Nutrient and taste preferences were measured at the beginning and end of each condition using the Leeds Food Preference Questionnaire. RESULTS Insulin levels were significantly reduced, and glucagon-like peptide 1 levels significantly increased during all exercise bouts compared with those during rest. Acylated ghrelin plasma levels were lower in the MICC and HIIC, but not in S-HIIC, compared with those in control. There were no significant differences for polypeptide YY3-36 plasma levels, hunger or fullness ratings, EI, or food reward. CONCLUSIONS Our findings suggest that, in overweight/obese individuals, isocaloric bouts of moderate- or high-intensity exercise lead to a similar appetite response. This strengthens previous findings in normal-weight individuals that acute exercise, even at high intensity, does not induce any known physiological adaptation that would lead to increased EI.

A randomised controlled study of the long-term effects of exercise training on mortality in elderly people: study protocol for the Generation 100 study

Introduction Epidemiological studies suggest that exercise has a tremendous preventative effect on morbidity and premature death, but these findings need to be confirmed by randomised trials. Generation 100 is a randomised, controlled study where the primary aim is to evaluate the effects of 5 years of exercise training on mortality in an elderly population. Methods and analysis All men and women born in the years 1936–1942 (n=6966), who were residents of Trondheim, Norway, were invited to participate. Between August 2012 and June 2013, a total of 1567 individuals (790 women) were included and randomised to either 5 years of two weekly sessions of high-intensity training (10 min warm-up followed by 4×4 min intervals at ∼90% of peak heart rate) or, moderate-intensity training (50 min of continuous work at ∼70% of peak heart rate), or to a control group that followed physical activity advice according to national recommendations. Clinical examinations, physical tests and questionnaires will be administered to all participants at baseline, and after 1, 3 and 5 years. Participants will also be followed up by linking to health registries until year 2035. Ethics and dissemination The study has been conducted according to the SPIRIT statement. All participants signed a written consent form, and the study has been approved by the Regional Committee for Medical Research Ethics, Norway. Projects such as this are warranted in the literature, and we expect that data from this study will result in numerous papers published in world-leading clinical journals; we will also present the results at international and national conferences. Trial registration number Clinical trial gov NCT01666340.

Fatigue May Contribute to Reduced Physical Activity Among Older People: An Observational Study

BACKGROUND Fatigue is one of the most commonly reported symptoms in primary care and perceived by older people as an overwhelming and distressing experience that restricts their activity and social participation. Self-reported fatigue is complex and multifactorial, with relatively little known about the causes and impacts among older people. This study tested the association between fatigue and objectively measured physical activity in a large cohort of older adults and identified factors that may explain this association. METHODS Using cross-sectional data from 980 community-living 70- to 77-year-olds, the associations between self-reported fatigue and four physical activity outcomes derived from an accelerometer-based activity monitor were tested. Attenuating effects on the association of age, gender, body mass index (BMI), physical condition, comorbidity, depression, and sleep quality were evaluated. RESULTS Nine percent of the sample reported being fatigued. Fatigued individuals had 1,150 fewer steps/day, 9 minutes/day less of moderate-vigorous activity, 12 minutes/day less of daily activity, and 15% fewer counts/minute, when compared with those not fatigued. BMI, physical condition, and comorbidity attenuated the association, and final regression models including these variables explained most (56%-72%) of the association between fatigue and activity. CONCLUSIONS Fatigue was associated with clinically important reductions in daily physical activity levels of older people. The findings show BMI, physical condition (in particular cardiorespiratory fitness), and comorbidity to be important factors in explaining the fatigue-physical activity association. Modification of these factors may facilitate increases in daily activity levels by lessening fatigue.

Cardiorespiratory Fitness, Sedentary Time, and Cardiovascular Risk Factor Clustering.

PURPOSE Prolonged sedentary time (ST) is associated with cardiovascular risk factors (CV-RF) independent of physical activity (PA). Whether a high level of cardiorespiratory fitness (CRF) can modify the deleterious health consequences related to high ST is not known. METHODS We performed a cross-sectional study of 12,274 men and 14,209 women (≥20 yr) without known cardiovascular disease. Self-reported ST measurements during a regular day were divided into three sex-specific equally sized groups (≤4, 5 to <7, and ≥7 h·d(-1)). CRF was estimated (eCRF) using a previously validated nonexercise model. Using logistic regression analyses, adjusted odds ratios (OR) and 95% confidence intervals (CI) were estimated for the association of ST with CV-RF clustering and for the potential modifying effect of eCRF. RESULTS Each hour increase in ST was associated with 5% and 4% greater likelihood of having CV-RF clustering independent of PA in men and women, respectively. Among the participants with higher levels of eCRF, the adjusted OR values associated with ≥7 h·d(-1) of ST were 0.92 (0.56-1.51) for men and 1.16 (0.49-2.74) for women, compared with men and women with low ST (≤4 h·d(-1)) and high eCRF levels. In combined analyses of eCRF, PA, and ST, compared with the reference group of participants meeting the recommendations, ≤4 h·d(-1) of ST and high eCRF, the OR values were 0.63 (0.27-1.44) and 0.65 (0.14-3.07) in fit men and women with ≥7 h·d(-1) of ST, which did not meet the recommendations. Men and women meeting the PA recommendations, but were unfit, had significantly increased odds of having CV-RF clustering across levels of ST. CONCLUSION High levels of eCRF abolished the increased odds of having CV-RF clustering associated with high ST, even among those individuals who did not meet the current PA recommendations.

Sedentary Time, Cardiorespiratory Fitness, and Cardiovascular Risk Factor Clustering in Older Adults--the Generation 100 Study

OBJECTIVE To determine whether meeting physical activity (PA) recommendations and/or having high age-specific cardiorespiratory fitness (CRF) attenuate the adverse effect of prolonged sedentary time on cardiovascular risk factor (CV-RF) clustering in older adults. PATIENTS AND METHODS We conducted a cross-sectional study of Norwegian women (495) and men (379) aged 70 to 77 years from August 22, 2012, through June 30, 2013. Sedentary time and PA were assessed by accelerometers and CRF by directly measured peak oxygen uptake (VO2peak). Logistic regression was used to estimate adjusted odds ratios (ORs) and CIs for the association between sedentary time and prevalence of CV-RF clustering (≥3 of the following: hypertension, high blood glucose level, high waist circumference, low high-density lipoprotein cholesterol level, or high triglyceride level) and for the modifying effect of PA and CRF. RESULTS Overall, 163 of the 495 women (32.9%) and 140 of the 379 men (36.9%) had CV-RF clustering. Each additional hour of sedentary time was associated with 22% (OR, 1.22; 95% CI, 1.02-1.45) and 27% (OR, 1.27; 95% CI, 1.04-1.55) higher likelihood of having CV-RF clustering in women and men, respectively, whereas a 1-metabolic equivalent decrement in VO2peak corresponded to 57% (OR, 1.57; 95% CI, 1.34-1.84) and 67% (OR, 1.67; 95% CI, 1.44-1.95) higher likelihood of CV-RF clustering in women and men, respectively. High CRF (VO2peak >27.5 mL/kg per minute in women and >34.4 mL/kg per minute in men) attenuated the adverse effects of high sedentary time on CV-RF clustering, even among individuals not meeting recommendations for PA. CONCLUSION High age-specific CRF fully attenuates the adverse effect of prolonged sedentary time on CV-RF clustering, independent of meeting the PA consensus recommendation in older adults.

Correlates of Objectively Measured Physical Activity Among Norwegian Older Adults: The Generation 100 Study.

The aim of this study was to identify how demographics, physical activity (PA) history, and environmental and biological correlates are associated with objectively measured PA among older adults. PA was assessed objectively in 850 older adults (70-77 years, 48% females) using the ActiGraph GT3X+ activity monitor. Hierarchical multiple regression analysis was used to identify important PA correlates. The included correlates explained 27.0% of the variance in older adults PA. Cardiorespiratory fitness (CRF), gender, and season were the most important correlates, explaining 10.1%, 3.9%, and 2.7% of the variance, respectively. PA was positively associated with CRF, females were more physically active than males, and PA increased in warmer months compared with colder months. This is, to our knowledge, the largest study of PA correlates in older adults that has combined objectively measured PA and CRF. Our findings provide new knowledge about how different correlates are associated with PA.

Cardiorespiratory Reference Data in Older Adults: The Generation 100 Study.

Purpose Cardiorespiratory fitness (CRF) is regarded a clinical vital sign, and accurate reference values for all age groups are essential. Little data exist on CRF and cardiorespiratory function in older adults. The aim of this study was to provide normative values for CRF and cardiorespiratory function in older adults, including people with history of cardiovascular diseases (CVD). Methods In total, 1537 (769 women) participants age 70 to 77 yr underwent clinical examinations and cardiopulmonary exercise tests. Peak oxygen uptake (V˙O2peak), ventilation (V˙Epeak), expiration of carbon dioxide (VV˙CO2peak), breathing frequency (BFpeak), tidal volume (VTpeak), oxygen pulse (O2 pulsepeak), ventilatory efficiency (EqV˙O2peak and EqV˙CO2peak), and 1-min HR recovery were assessed. Results Men compared with women had higher V˙O2peak (31.3 ± 6.7 vs 26.2 ± 5.0 mL·min−1·kg−1), BFpeak (41.8 ± 8.0 vs 39.7 ± 7.1 breaths per minute), VTpeak (2.3 ± 0.5 vs 1.6 ± 0.3), O2 pulsepeak (16.4 ± 3.2 vs 11.3 ± 2.0), V˙CO2peak (2.9 ± 0.2 and 1.9 ± 0.1 L·min−1), V˙Epeak (96.2 ± 21.7 vs 61.1 ± 21.6 L·min−1), EqV˙O2peak (38.0 ± 6.9 vs 35.1 ± 5.6), and EqV˙CO2peak (33.5 ± 5.7 vs 31.9 ± 4.5). Women and men with CVD had lower V˙O2peak (14% and 19%), peak HR (5% and 6%), V˙Epeak (8% and 10%), VTpeak (7% and 4%), and lower EqV˙CO2peak (4% and 6%) compared with their healthy counterparts, respectively. Compared with healthy women and men, 1-min HR recovery was 12% and 16% lower for women and men with CVD. Conclusions This study represents the largest reference material on directly measured CRF and cardiorespiratory function in older men and women, with and without CVD. This novel information will help researchers and clinicians to interpret data form cardiopulmonary testing in older adults.

Are Older Adults Physically Active Enough - A Matter of Assessment Method? The Generation 100 Study

Introduction Physical activity (PA) is beneficial for general health. As a result, adults around the world are recommended to undertake regular PA of either absolute or relative intensity. Traditionally, adherence to PA recommendation is assessed by accelerometers that record absolute intensity thresholds. Since ageing often results in a decrease in cardiorespiratory fitness (CRF), older adults (aged > 65 years) might be more susceptible to not meeting the PA recommendation when measured in absolute terms. The aim of the present study was to compare the adherence to the PA recommendation using both absolute and relative thresholds. Additionally, we aimed to report the reference values for overall PA in a large sample of Norwegian older adults. Methods PA was assessed for 7 days using the Actigraph GT3X+ accelerometer in 1219 older adults (624 females) aged 70–77 years. Overall PA was measured as counts per minute (CPM) and steps. Absolute and relative moderate-to-vigorous PA (MVPA) thresholds were applied to quantify adherence to PA recommendation. The relative MVPA thresholds were developed specifically for the Generation 100 population sample. CRF was directly measured as peak oxygen uptake (VO2peak). Results Proportions meeting PA recommendation were 29% and 71% when utilizing absolute and relative MVPA, respectively. More females met the relative PA recommendation compared to males. Overall PA was higher among the youngest age group. Older adults with medium- and high levels of CRF were more physically active, compared to those with the lowest levels of CRF. Conclusion This is the first study to compare adherence to PA recommendation, using absolute and relative intensity thresholds among older adults. The present study clearly illustrates the consequences of using different methodological approaches to surveillance of PA across age, gender and CRF in a population of older adults.