Bo-Egil Hustvedt

Reliability and validity of the international physical activity questionnaire in the Nord-Trondelag health study (HUNT) population of men.

BackgroundThere is no standardized method for the assessment of physical activity (PA). Therefore it is important to investigate the validity and comparability of different measures. The International Physical Activity Questionnaire (IPAQ) has been developed as an instrument for cross-national assessment of PA and has been validated in 12 countries. These instruments have acceptable measurement properties for monitoring population levels of PA among 18–65 year-old adults in diverse settings. However, there are some concerns that IPAQ may over-report PA.The purpose of this study is to evaluate the reliability and validity of IPAQ, short version, last 7-days in the Nord-Trøndelag Health Study (HUNT) population of men.MethodsThe questionnaire was administered twice to a random sample of 108 men aged 20–39 and validity by comparing results with VO2max and ActiReg, an instrument that measures PA and energy expenditure (EE). ActiReg discriminates between the body positions: stand, sit, bend forward and lie and also registers if there is motion or not in each of them or both.ResultsOur results for reliability of the IPAQ short version were good for vigorous and fair for moderate activities. Intraclass correlations ranged from a low of 0.30 for moderate activity hours, to a high of 0.80 for sitting hours. Concerning validity, our results suggest that total IPAQ vigorous PA was a moderately good measure of vigorous activity, having moderately strong, significant correlations with VO2max, r = 0.41 (p ≤ 0.01), but correlated not with metabolic equivalent (METs) values of 6 or more measured with ActiReg. Only total IPAQ walking was fair correlated with METs 1–3 and METs 3–6, respectively r = -0.27 and 0.26 (p ≤ 0.05). The index for IPAQ sitting hours per week was moderate correlated with METs values of 1–3 and negatively correlated with METs values of 3–6. Classification of PA in three levels (low, moderate and high) correlated also most strongly with VO2max (0.31 p ≤ 0.01) and METs 3–6 and METs 1–3 from ActiReg (r = 0.32 and -0.31, p ≤ 0.01). Classification of BMI in three levels (normal, overweight and obese) correlated most strongly negative with VO2max (-0.42 p ≤ 0.01) and MJ from ActiReg (r = 0.31 p ≤ 0.01).ConclusionOur results indicate that IPAQ short version for men has acceptable reliability and criterion validity for vigorous activity and sitting. Walking has moderate reliability. Only the IPAQ for walking had a fair correlation with METs 6+. The questions about moderate activity had fair reproducibility and correlated poorly with most comparison measures.

Description and validation of the ActiReg®: a novel instrument to measure physical activity and energy expenditure

The ActiReg (PreMed AS, Oslo, Norway) system is unique in using combined recordings of body position and motion alone or combined with heart rate (HR) to calculate energy expenditure (EE) and express physical activity (PA). The ActiReg has two pairs of position and motion sensors connected by cables to a battery-operated storage unit fixed to a waist belt. Each pair of sensors was attached by medical tape to the chest and to the front of the right thigh respectively. The collected data were transferred to a personal computer and processed by a dedicated program ActiCalc. Calculation models for EE with and without HR are presented. The models were based on literature values for the energy costs of different activities and therefore require no calibration experiments. The ActiReg system was validated against doubly labelled water (DLW) and indirect calorimetry. The DLW validation demonstrated that neither EE calculated from ActiReg data alone (EEAR) nor from combined ActiReg and HR data (EEAR-HR) were statistically different from DLW results. The EEAR procedure causes some underestimation of EE >11 MJ corresponding to a PA level >2.0. This underestimation is reduced by the EEAR-HR procedure. The objective recording of the time spent in different body positions and at different levels of PA may be useful in studies of PA in different groups and in studies of whether recommendations for PA are being met. The comparative ease of data collection and calculation should make ActiReg a useful instrument to measure habitual PA level and EE.

Validation of energy intake estimated from a food frequency questionnaire: a doubly labelled water study

Objective: The validation of dietary assessment methods is critical in the evaluation of the relation between dietary intake and health. The aim of this study was to assess the validity of a food frequency questionnaire by comparing energy intake with energy expenditure measured with the doubly labelled water method.Design: Total energy expenditure was measured with the doubly labelled water (DLW) method during a 10 day period. Furthermore, the subjects filled in the food frequency questionnaire about 18–35 days after the DLW phase of the study was completed.Subjects: Twenty-one healthy, non-pregnant females volunteered to participate in the study; only 17 subjects completed the study.Results: The group energy intake was on average 10% lower than the energy expenditure, but the difference was not statistically significant. However, there was a wide range in reporting accuracy: seven subjects were identified as acceptable reporters, eight as under-reporters and two were identified as over-reporters. The width of the 95% confidence limits of agreement in a Bland and Altman plot for energy intake and energy expenditure varied from −5 to 3 MJ.Conclusion: The data showed that there was substantial variability in the accuracy of the food frequency questionnaire at the individual level. Furthermore, the results showed that the questionnaire was more accurate for groups than individuals.

Validation of a pre-coded food diary used among 13-year-olds: comparison of energy intake with energy expenditure

OBJECTIVE To validate energy intake (EI) estimated from pre-coded food diaries against energy expenditure (EE) measured with a validated position-and-movement monitor (ActiReg) in groups of 13-year-old Norwegian schoolchildren. DESIGN Two studies were conducted. In study 1 the monitoring period was 4 days; participants recorded their food intake for four consecutive weekdays using food diaries and wore the ActiReg during the same period. In study 2 the monitoring period was 7 days; participants recorded their food intake for four consecutive days but wore the ActiReg for a whole week. SETTINGS Participants were recruited from grade 8 in a school in and one outside Oslo (Norway). SUBJECTS Forty-one and 31 participants from study 1 and 2, respectively, completed the study. RESULTS The group average EI was 34% lower than the measured EE in study 1 and 24% lower in study 2. The width of the 95% confidence limits of agreement in a Bland-Altman plot for EI and EE varied from -0.2 MJ to 8.2 MJ in study 1 and from -2.3 MJ to 6.9 MJ in study 2. The Pearson correlation coefficients between reported energy intake and expenditure were 0.47 (P=0.002) in study 1 and 0.74 (P<0.001) in study 2. CONCLUSION The data showed that there was substantial variability in the accuracy of the food diary at the individual level. Furthermore, the diary underestimated the average energy intake. The ability of the food diary to rank individuals according to energy intake was found to be good in one of the studies and moderate in the other.

The Effect of Ventromedial Hypothalamic Lesions on Metabolism and Insulin Secretion in Rats on a Controlled Feeding Regimen

The metabolic effect of ventromedial hypothalamic (VMH) lesions, which are known to cause hyperphagia and obesity, has been studied in rats kept on a controlled light and food regimen. The animals were sacrificed at 4 different times during the second postoperative day. A feeding-induced hypersecretion of insulin was found to the VMH-lesioned animals. It was accompanied by a marked hypoglycemia as compared to the control groups during the feeding period. The glycogen content of liver and diaphragm in the lesioned groups is increased as compared to the controls during the same period. The VMH-lesioned animals showed hypertriglyceridemia both in the fed and fasted state, whereas the postabsorptive plasma levels of free fatty acids and glycerol were decreased. An increased level of urea was observed in all lesioned groups. This is in accordance with the demonstrated protein catabolism which follows VMH lesions.

Increased hepatic triacylglycerol secretion in fasted rats with ventromedial hypothalamic lesions

Adult female rats with lesions in the ventromedial hypothalamic area and sham-operated controls were given Triton WR 1339 intravenously after 24 h without food for measurement of liver triacylglycerol secretion rate. Tritiated water was injected for measurement of lipogenesis in liver, perirenal and subcutaneous adipose tissues in vivo. The experiments were performed on unrestrained animals with a chronically implnted venous heart cannula after 24 h without food. By the use of this technique, anesthesia and handling of the animals during the experiments was avoided. The following differences in the lesioned animals compared to the sham-operated controls were found: relative hypertriglyceridemia. A significant increase of triacylglycerol accumulation in the plasma. Increased incorporation of 3H FROM 3H20 into liver fatty acids. The experiments demonstrate that hepatic lipid synthesis during fasting is greater in the lesioned than in the control animals, but not high enough to account for the increased triacylglycerol secretion. A shift in the hepatic metabolism of fatty acids, leading to greater triacylglycerol formation at the expense of other processes is therefore suggested. The possible role of insulin in these metabolic changes is discussed.

Correlation between altered acetate utilization and hyperphagia in rats with ventromedial hypothalamic lesions

Abstract Incorporation of a tracer dose of acetate-1- 14 C given by intraperitoneal injection into normal and VMH-lesioned rats 2 days after surgery has been studied in vivo. To exclude adaptive metabolic effects due to meal-feeding and hyperphagia, the food intake of the lesioned animals was kept close to normal by using an automated food dispenser. The results show decreased recovery of 14 C activity as 14 CO 2 in the lesioned rats as compared to untreated animals during the first 4 hr after the injection, whereas the 14 C incorporation into body lipids was significantly increased in the lesioned animals. The change in acetate utilization is shown to develop gradually during the first 2–3 days postoperatively. Moreover, the individual retention of 14 C activity from acetate-1- 14 C is correlated to the subsequent gain in body weight during 8 days of ad-lib. feeding. In conclusion, the results clearly demonstrate an altered metabolism in the VMH-lesioned rat, so as to promote accumulation of body fat, even when hyperphagia is prevented. Furthermore, the concept “regulatory obesity” is reexamined in view of the findings presented.

Validity of the ActiReg system and a physical activity interview in assessing total energy expenditure in long-term survivors after total gastrectomy.

BACKGROUND & AIMS Malnutrition is common after total gastrectomy. There is a need for clinically useful methods to assess energy requirements. We aimed to validate measurements of energy expenditure by an activity monitor (ActiReg) and a physical activity interview (HPAQ(modified)), in long-term survivors after gastrectomy for gastric carcinoma, using doubly labelled water as reference method. METHODS Total energy expenditure (TEE) was estimated by DLW (14 days), ActiReg (3 days) and HPAQ(modified) (7 days) in 15 patients. Measurements were repeated after 12 months. Basal metabolic rate was measured with indirect calorimetry. RESULTS ActiReg and HPAQ(modified) both underestimated TEE by 180 (+/-254 SD) and 130 (+/-326 SD)kcalday(-1), i.e. 14% vs. 12%, respectively. However, this was evident only at higher levels of physical activity (PAL(DLW)> or =1.65), whereas at lower levels (PAL<1.65) no difference was found. There were no changes in TEE over time independent of the method used. DLW and ActiReg had approximately the same width of the 95% confidence interval of this estimate, while it was 2.4 times larger by HPAQ(modified). CONCLUSION Both simple methods underestimated total energy expenditure at higher, but not at lower physical activity levels. The ActiReg method appears useful to estimate changes in TEE over time.

The hepatic secretion of lecithin: cholesterol acyltransferase in rats with increased secretion of triglycerides due to ventromedial hypothalamic lesions

Lecithin:cholesterol acyltransferase (LCAT) is postulated to take care of excess cholesterol formed during metabolism of triglyceride (TG)-rich lipoproteins. To test this hypothesis the relationship between secretion of LCAT and TG have been investigated in rats with ventromedial hypothalamic lesions which lead to increased hepatic secretion of TG. 1. The increased plasma concentration of TG in rats with ventromedial hypothalamic lesions was positively correlated to the activity of LCAT in plasma. 2. Incubation of hepatocytes isolated from such rats revealed a positive linear correlation between secretion of TG and of LCAT. 3. The secretion of unesterified cholesterol was neither correlated to the secretion of the acyltransferase nor to the TG.

Protein Depletion and Energy Retention in Rats with Ventromedial Hypothalamic Lesions

The catabolic effect of bilateral lesions in the ventromedial are of the hypothalamus (VMH) was studied in nitrogen-balance experiments and compared with the effect of a sham-operation in control animals. A transitory (24 h) increase in urine nitrogen was found in the controls, while in the lesioned animals, a persistent increase was found as long as the animals were fed. Fasting (48 h) eliminated the difference in urea excretion between the groups. Food-dependent effects of the VMH lesion are suggested. The changes in body and organ composition of VMH-lesioned animals, kept for 4 months on a food intake close to normal, were studied. The massive increase of body lipids and marked decrease of body protein and water was primarily due to increased subcutaneous-and abdominal-fat, and reduced skeletal and skin protein. An almost normal composition of the liver and close to normal amounts of protein in the viscera demonstrate that at least some tissues in VMH animals are able to maintain a normal protein content. Hyperphagia as a means to counteract the increased amino acid catabolism and to sustain the lean body mass is discussed.