Katriina Kukkonen-Harjula

Does physical activity prevent weight gain--a systematic review.

This paper is a systematic review of research data on associations between physical activity and weight gain, with or without prior weight reduction. The selected studies were restricted to Caucasian (white) adults. Most studies with data on physical activity collected at follow‐up, found an inverse association between physical activity and long‐term weight gain. This finding was present in studies both with and without prior weight reduction. Prospective studies with physical activity measured at baseline, and randomized weight reduction interventions, gave inconsistent results regarding the effects of increased physical activity on weight change. The weighted mean weight regain in randomized studies with or without exercise training was 0.28 and 0.33 kg/month, respectively. Based on observational studies, it seemed that an actual increase in energy expenditure of physical activity of approximately 6300–8400 kJ/week (1500–2000 kcal/week) is associated with improved weight maintenance. This is more than was prescribed in most randomized trials, and certainly more than the participants actually achieved. Adherence to a prescribed exercise programme remains a big challenge. Before new methods to improve exercise adherence are found, the role of prescribed physical activity in prevention of weight gain remains modest.

Sleep-related disturbances and physical inactivity are independently associated with obesity in adults

Objective:To study relationships between obesity, physical inactivity and sleep-related disturbances (obstructive sleep apnea (OSA), sleep duration, sleep disturbances concomitant with daytime tiredness) in adults (⩾30 years).Design:Cross-sectional study with a random population sample.Participants:A total of 3377 men (mean age 52.3, s.d. 14.8, years) and 4264 women (56.4, s.d. 17.2, years).Main outcome measures:Dependent variables, measured: Waist circumference (WC) and body mass index (BMI). Independent variables, from a detailed interview/questionnaire: probable OSA, other sleep-related disturbances, sleep duration, type and frequency of leisure physical activity. Age, mental health, smoking and education were included in analyses as potential confounders.Results:In men, OSA and physical inactivity increased likelihood for abdominal obesity (WC ⩾102 cm). Physical inactivity also increased, but long (⩾9 h/day) sleep decreased likelihood for abdominal overweight (WC: 94–101 cm) in men. In women, abdominal obesity (WC ⩾88 cm) was associated positively with OSA, moderate sleep-related disturbances, and physical inactivity. Education modulated the influence of age on abdominal obesity in both genders. Using BMI as the dependent variable did not change the general information obtained by the model. In addition, abdominal obesity was found to be an independent risk factor also in multivariable models predicting categories of a combined sleep duration and sleep disturbances.Conclusions:Sleep duration and sleep-related disturbances are associated with obesity, even after controlling for OSA and physical inactivity. The results support the hypothesis of vicious circle between sleep and obesity.

Eating control and physical activity as determinants of short-term weight maintenance after a very-low-calorie diet among obese women.

OBJECTIVE:To test the hypothesis that eating control and physical activity help maintain weight and waist circumference after a very-low-calorie diet.DESIGN:A 12 week weight reduction (WR) phase, followed by a 40 week weight maintenance (WM) phase. For the latter, the subjects were randomised into a no-exercise group and one of two groups with a walking program.SUBJECTS:Eighty-five obese (body mass index 29–46, mean 34), clinically healthy, premenopausal women.MEASUREMENTS:Body weight, waist circumference, body composition, the measuring restrained eating, disinhibition and hunger, measured by Three Factor Eating Questionnaire (TFEQ), binge eating measured by the Bulimic Investigatory Test of Edinburgh (BITE), and number of daily steps measured by a pedometer.RESULTS:The change (Δ) in weight during WM was predicted by the following regression: Δweight (kg)=5.23+0.45 Δweight during WR+0.66 disinhibition during WM−0.00039 daily steps during WM, r 2=0.46, SEE 3.3 kg. The change in waist circumference during WM was predicted as Δwaist (cm)=0.76+0.75 Δweight during WM−0.00021 daily steps during WM, r 2=0.67, SEE 2.6 cm. Exercise group assignment did not affect the changes in weight, waist circumference, or indicators of eating control during the maintenance program.CONCLUSIONS:Control of overeating, as indicated by a lower disinhibition factor of the TFEQ, and daily physical activity, as indicated by a higher number of daily steps, were positive and independent predictors of weight maintenance after a very-low-calorie diet. The number of daily steps showed an independent association with change in waist circumference during weight maintenance, even after adjustment for weight change.

Haemodynamic and hormonal responses to heat exposure in a Finnish sauna bath

SummaryEight healthy young men were studied during three periods of heat exposure in a Finnish sauna bath: at 80° C dry bulb (80 D) and 100° C dry bulb (100 D) temperatures until subjective discomfort, and in 80° C dry heat, becoming humid (80 DH) until subjective exhaustion. Oral temperature increased 1.1° C at 80 D, 1.9° C at 100 D and 3.2° C at 80 DH. Heart rate increased about 60% at 80 D, 90% at 100 D and 130% at 80 DH. Plasma noradrenaline increased about 100% at 80 D, 160% at 100 D and 310% at 80 DH. Adrenaline did not change. Plasma prolactin increased 2-fold at 80 D, 7-fold at 100 D and 10-fold at 80 DH. Blood concentrations of the beta-endorphin immunoreactivity at 100 D, adrenocorticotropic hormone (ACTH) at 100 D and 80 DH, growth hormone at 100 D and testosterone at 80 DH also increased, but cortisol at 80 D and 100 D decreased. The plasma prostaglandin E2 and serum thromboxane B2 levels did not change. Patterns related to heat exposure were observed for heart rate, plasma noradrenaline, ACTH and prolactin in the three study periods.

Walking trials in postmenopausal women: effect of low doses of exercise and exercise fractionization on coronary risk factors

We studied the fractionization of walking training and searched for the minimum dose to affect coronary risk factors in two randomized controlled trials. Altogether 134 (Study I) and 121 (Study II) healthy, sedentary postmenopausal women started the trials, and 130 (Study I) and 116 (Study II) completed them. In Study I the exercise intensity was 65% of the maximal aerobic power (VO2max) and a total of 300 kcal was expended in one (Group W1) or two (Group W2) daily walking bouts. In Study II the exercise was continuous, and the exercise intensity (% of VO2max) and energy expenditure (kcal session−1) were 55% and 300 kcal (Group W3), 45% and 300 kcal (Group W4), 55% and 200 kcal (Group W5) and 45% and 200 kcal (Group W6). All the subjects walked 5 days a week. The outcome measures were blood pressure, serum lipoproteins and blood glucose and plasma insulin in fasting state and also during 2‐h oral glucose tolerance test in Study I. There was no change in diastolic pressure in the original study groups, but in the combined exercise group (W1+W2) in Study I, the mean diastolic pressure declined by −3.0 mmHg (95% con‐fidence interval (CI) −5.5 to −0.4) (P=0.025) in comparison with that of the controls. The mean blood glucose declined by −0.21 mmol L−1 (CI −0.33 to −0.09) in Group W1 and −0.13 mmol L−1 (CI −0.25 to −0.01) in Group W2 compared to controls (P=0.03). Also the 2‐h glucose concentration decreased in Groups W1 and W2 compared to controls. Systolic blood pressure, serum lipoproteins and insulin levels did not change in Study I or Study II. We conclude that our training program with the greatest exercise dose, exercise intensity 65% of VO2max and weekly expenditure of 1500 kcal had a minimal, positive effect on diastolic pressure and blood glucose, and the effect was similar in one or two daily exercise session groups. This exercise dose is probably close to the minimum to affect coronary risk factors in healthy postmenopausal women. To get a more pronounced and clinically relevant effect, a greater exercise dose is needed.

Hysteroscopic tubal sterilization: a systematic review of the Essure system

OBJECTIVE To update the evidence of the efficacy and safety of the Essure system. Female sterilization has undergone changes in the last decade. Besides laparoscopic tubal occlusion, the Essure system is now a viable option, with about 200,000 women sterilized using this method. DESIGN The review is based on the report of the Alberta Heritage Foundation for Medical Research and completed with systematic literature searches up to April 8, 2008. SETTING The Managed Uptake of Medical Methods program of the Finnish National Research and Development Center for Health and Welfare. PATIENT(S) Women over 30 years, who had been sterilized by the Essure method. INTERVENTION(S) Hysteroscopic tubal sterilization using Essure system. MAIN OUTCOME MEASURE(S) Efficacy/effectiveness, adverse events, costs. RESULT(S) Sterilization by Essure can be performed under local anesthesia or with oral analgesics in ambulatory settings. However, sterilization is not immediate and women must use additional contraception for 3 months until permanent tubal occlusion is verified by transvaginal ultrasound, hysterosalpingosonography, hysterosalpingography, or pelvic radiography. The evidence on efficacy and safety is mainly available from short follow-up case series but shows good efficacy and safety of the Essure system. Only a few small risks are associated with the procedure. Two economic studies, one of which implemented Essure as an in-office procedure, suggest that Essure could be more cost-effective than laparoscopic sterilization, but more information on the total cost is needed. CONCLUSION(S) The Essure system appears to be safe, permanent, irreversible, and a less invasive method of contraception compared with laparoscopic sterilization.

Physiological effects of walking and cycling to work

Sixty‐eight previously sedentary volunteers (38 men and 30 women) were randomly divided into active and control groups and subjected to a 10‐week programme of walking or cycling while commuting to and from work. The active commuters and the controls complied with the programme on 75–78% and 92% of the workdays, respectively. The mean walking distance was 3.5 km and that of cycling 10 km. Cardiorespiratory strain of approximately 50% of maximal oxygen uptake V̇O2max in walking and 60% of V̇O2max in cycling was observed. Statistically consistent improvements caused by active commuting were seen in cardiorespiratory responses to both maximal and submaximal work and in metabolic response to submaximal work. Cycling was more effective than walking. These findings indicate that low‐intensity walking and cycling to and from work improved cardiorespiratory and metabolic fitness.

Pulse wave velocity reference values in healthy adults aged 26–75 years

The stiffening of arteries is associated with various cardiovascular diseases. Arterial stiffening can be studied utilizing arterial pulse wave velocity (PWV), but the absence of reliable reference values for PWV has limited its use in clinical practice. The aim of this study was to establish a range of reference values for PWV. PWV was examined by measuring the time difference of systolic pulse waves in arteries from the aortic arch to the popliteal artery using whole‐body impedance cardiography (ICG). The study population consisted of 799 individuals (age range 25–76 years), 283 of whom had no evidence of cardiovascular disease, and a low burden of risk factors was selected to represent an apparently healthy population. In healthy study population, PWV was higher in males (8·9 ± 1·8 m s−1) than females (8·1 ± 2·0 m s−1, P<0·001). Young males had lower PWV values than old males. Correspondingly, young females also had lower PWV values than old females. PWV was clearly associated with age, and PWV was higher in young and middle‐aged males than in females. There was no statistically significant difference between old males and females in PWV. In conclusion, whole‐body ICG provides a practical method for PWV measurement. Reference values can be useful in the clinical management of patients, especially in detecting early vascular disease or an increased risk of cardiovascular complications.

Food selection and eating behaviour during weight maintenance intervention and 2-y follow-up in obese men

OBJECTIVE: The aim was to assess long-term changes in food consumption and eating behaviour during and 2 y after dietary counselling in weight-reduced obese men.DESIGN: Observational study from a randomised controlled trial.SETTING: Outpatient clinic of a research institute.SUBJECTS: A total of 36 subjects with complete data on food intake during the study. Subjects were obese (mean body mass index (BMI) 32.8 kg/m2) men aged 35–50 y, recruited by media advertising.INTERVENTIONS: Dietary counselling was included in 2 months weight reduction with very-low-energy-diet and in 6 months weight maintenance programme, which also included physical activity counselling. This was followed by a 23 months unsupervised follow-up with yearly assessments. Food intake was assessed six times during the study by 4-day food records. Eating behaviour was assessed by Three-Factor Eating Questionnaire (TFEQ).RESULTS: Increased consumption of low-fat cheese, low-fat margarine, vegetables and high-fibre bread, and decreased consumption of sugar, sausage, high-fat cheese, high-fat margarine, fat products and sweets were observed during dietary counselling. Most of these changes returned later to prestudy consumption level. The relapse in dietary changes was partly associated with scoring low in restraint and high in disinhibition and hunger.CONCLUSION: In obese men, long-term maintenance of dietary changes was difficult. New ways to ease self-monitoring and increase self-efficacy might be necessary to improve maintenance of dietary changes.

Self-guided brisk walking training with or without poles: a randomized-controlled trial in middle-aged women

Walking with poles (Nordic walking, NW) has become popular. We compared training responses of brisk walking (W) or NW on cardiorespiratory and neuromuscular fitness. We randomized 121 non‐obese sedentary women (aged 50–60) to an NW or W group (NWG, WG), to train 40 min four times weekly for 13 weeks. Intensity was based on subjective perception of exertion. Cardiorespiratory performance was assessed in four levels corresponding to 50%, 65%, 80% and 100% of peak VO2. Fifty‐four NWG and 53 WG subjects completed the study. The mean intensity was about 50% of heart rate (HR) reserve. The baseline peak VO2 was 25.8 (SD 3.9) mL/min/kg. Both groups improved peak VO2 similarly (NWG 2.5 mL/min/kg, 95% confidence interval (CI) 1.9–3.3; WG 2.6, CI 1.9–3.3). In the submaximal stages while walking with or without poles, HR and lactate decreased after training in both groups, but the changes were not statistically significantly different between the groups. Of the neuromuscular tests after training, the only significant difference between the groups was in the leg strength in the one‐leg squat, favoring WG. In conclusion, both training modes improved similarly health‐enhancing physical fitness, and they were feasible and safe.