Self-monitoring of blood glucose versus self-monitoring of urine glucose in adults with newly diagnosed Type 2 diabetes receiving structured education: a cluster randomized controlled trial.

AIMS: To compare the effectiveness and acceptability of self-monitoring of blood glucose with self-monitoring of urine glucose in adults with newly diagnosed Type 2 diabetes. METHODS: We conducted a multi-site cluster randomized controlled trial with practice-level randomization. Participants attended a structured group education programme, which included a module on self-monitoring using blood glucose or urine glucose monitoring. HbA1c and other biomedical measures as well as psychosocial data were collected at 6, 12 and 18 months. A total of 292 participants with Type 2 diabetes were recruited from 75 practices. RESULTS: HbA1c levels were significantly lower at 18 months than at baseline in both the blood monitoring group [mean (se) -12 (2) mmol/mol; -1.1 (0.2) %] and the urine monitoring group [mean (se) -13 (2) mmol/mol; -1.2 (0.2)%], with no difference between groups [mean difference adjusted for cluster effect and baseline value = -1 mmol/mol (95% CI -3, 2); -0.1% (95% CI -0.3, 0.2)]. Similar improvements were observed for the other biomedical outcomes, with no differences between groups. Both groups showed improvements in total treatment satisfaction, generic well-being, and diabetes-specific well-being, and had a less threatening view of diabetes, with no differences between groups at 18 months. Approximately one in five participants in the urine monitoring arm switched to blood monitoring, while those in the blood monitoring arm rarely switched (18 vs 1% at 18 months; P < 0.001). CONCLUSIONS: Participants with newly diagnosed Type 2 diabetes who attended structured education showed similar improvements in HbA1c levels at 18 months, regardless of whether they were assigned to blood or urine self-monitoring.

Comparison of illness representations dimensions and illness representation clusters in predicting outcomes in the first year following diagnosis of type 2 diabetes: results from the DESMOND trial.

This article explores the utility of cluster analysis of illness representations, in comparison to analysing each dimension of the individual's illness representation, to predict an individual's response to diagnosis of type 2 diabetes. Participants in a large multi-centre randomised controlled trial of a self-management education intervention for people with type 2 diabetes, completed measures of illness beliefs (coherence, timeline, impact, seriousness, personal responsibility) and depression along with HbA1c and body mass index (BMI), at baseline 4, 8 and 12 months. The results of the cluster analysis were compared with an independent qualitative study of participants' responses to diagnosis and participation in the study. The quantitative analysis of 564 participants for whom complete data were available, identified four clusters of illness representations as the most parsimonious description of the data. The mean profiles of these clusters were comparable with groups identified by the independent qualitative analysis, and predicted the trajectory of illness outcomes over the 1-year follow-up. Combining illness beliefs into discrete clusters may be more useful in understanding patterns of responding to illness than using analysis of illness beliefs dimensions independently.

Delivering the diabetes education and self management for ongoing and newly diagnosed (DESMOND) programme for people with newly diagnosed type 2 diabetes: cost effectiveness analysis.

OBJECTIVES: To assess the long term clinical and cost effectiveness of the diabetes education and self management for ongoing and newly diagnosed (DESMOND) intervention compared with usual care in people with newly diagnosed type 2 diabetes. DESIGN: We undertook a cost-utility analysis that used data from a 12 month, multicentre, cluster randomised controlled trial and, using the Sheffield type 2 diabetes model, modelled long term outcomes in terms of use of therapies, incidence of complications, mortality, and associated effect on costs and health related quality of life. A further cost-utility analysis was also conducted using current "real world" costs of delivering the intervention estimated for a hypothetical primary care trust. SETTING: Primary care trusts in the United Kingdom. PARTICIPANTS: Patients with newly diagnosed type 2 diabetes. INTERVENTION: A six hour structured group education programme delivered in the community by two professional healthcare educators. MAIN OUTCOME MEASURES: Incremental costs and quality adjusted life years (QALYs) gained. RESULTS: On the basis of the data in the trial, the estimated mean incremental lifetime cost per person receiving the DESMOND intervention is pound209 (95% confidence interval - pound704 to pound1137; euro251, -euro844 to euro1363; $326, -$1098 to $1773), the incremental gain in QALYs per person is 0.0392 (-0.0813 to 0.1786), and the mean incremental cost per QALY is pound5387. Using "real world" intervention costs, the lifetime incremental cost of the DESMOND intervention is pound82 (- pound831 to pound1010) and the mean incremental cost per QALY gained is pound2092. A probabilistic sensitivity analysis indicated that the likelihood that the DESMOND programme is cost effective at a threshold of pound20 000 per QALY is 66% using trial based intervention costs and 70% using "real world" costs. Results from a one way sensitivity analysis suggest that the DESMOND intervention is cost effective even under more modest assumptions that include the effects of the intervention being lost after one year. CONCLUSION: Our results suggest that the DESMOND intervention is likely to be cost effective compared with usual care, especially with respect to the real world cost of the intervention to primary care trusts, with reductions in weight and smoking being the main benefits delivered.

Depressive symptoms in the first year from diagnosis of Type 2 diabetes: results from the DESMOND trial.

AIMS: To describe the course of depressive symptoms during the first year after diagnosis of Type 2 diabetes. METHODS: Post hoc analysis of data from a randomized controlled trial of self-management education for 824 individuals newly diagnosed with Type 2 diabetes. Participants completed the Depression scale of the Hospital Anxiety and Depression Scale after diagnosis and at 4, 8 and 12 months follow-up. Participants also completed the Problem Areas in Diabetes scale at 8 and 12 months follow-up. We present descriptive statistics on prevalence and persistence of depressive symptoms. Logistic regression is used to predict possible depression cases, and multiple regression to predict depressive symptomatology. RESULTS: The prevalence of depressive symptoms in individuals recently diagnosed with diabetes (18-22% over the year) was not significantly different from normative data for the general population (12%) in the UK. Over 20% of participants indicated some degrees of depressive symptoms over the first year of living with Type 2 diabetes; these were mostly transient episodes, with 5% (1% severe) reporting having depressive symptoms throughout the year. At 12 months post diagnosis, after controlling for baseline depressive symptoms, diabetes-specific emotional distress was predictive of depressive symptomatology. CONCLUSIONS: The increased prevalence of depressive symptoms in diabetes is not manifest until at least 1 year post diagnosis in this cohort. However, there are a significant number of people with persistent depressive symptoms in the early stages of diabetes, and diabetes-specific distress may be contributing to subsequent development of depressive symptoms in people with Type 2 diabetes.

Biomedical, lifestyle and psychosocial characteristics of people newly diagnosed with Type 2 diabetes: baseline data from the DESMOND randomized controlled trial.

AIMS: To describe the characteristics of newly diagnosed people with Type 2 diabetes (T2DM) and compare these with published studies. METHODS: Baseline data of participants recruited to the DESMOND randomized controlled trial conducted in 13 sites across England and Scotland were used. Biomedical measures and questionnaires on psychological characteristics were collected within 4 weeks of diagnosis. RESULTS: Of 1109 participants referred, 824 consented to participate (74.3%). Mean (+/- sd) age was 59.5 +/- 12 years and 54.9% were male. Mean HbA(1c) was 8.1 +/- 2.1% and did not differ by gender. Mean body mass index (BMI) was significantly higher in women (33.7 vs. 31.3 kg/m2; P < 0.001); 69% of women and 54% of men were obese (BMI > 30 kg/m2). Total cholesterol was significantly higher in women (5.6 vs. 5.2 mmol/l; P < 0.001). Overall, 14.7% reported smoking. Percentages reporting recommended levels of vigorous activity (> or = 3 times/week) and moderate activity (> or = 5 times/week) were 10.6 and 16.0%, respectively, and were lower in women. Specific illness beliefs included 73% being unclear about symptoms and only 54% believing diabetes is a serious condition. Symptoms indicative of depression were reported by significantly more women than men (16.1% vs. 8.2%; P = 0.001). CONCLUSION: Data from this large and representative cohort of newly diagnosed people with T2DM show that many have modifiable cardiovascular risk factors. Comparison with the literature suggests that the profile of the newly diagnosed may be changing, with lower HbA1c and higher prevalence of obesity. Many expressed beliefs about and poor understanding of their diabetes that need to be addressed in order for them to engage in effective self-management.

Effectiveness of the diabetes education and self management for ongoing and newly diagnosed (DESMOND) programme for people with newly diagnosed type 2 diabetes: cluster randomised controlled trial.

OBJECTIVE: To evaluate the effectiveness of a structured group education programme on biomedical, psychosocial, and lifestyle measures in people with newly diagnosed type 2 diabetes. DESIGN: Multicentre cluster randomised controlled trial in primary care with randomisation at practice level. SETTING: 207 general practices in 13 primary care sites in the United Kingdom. PARTICIPANTS: 824 adults (55% men, mean age 59.5 years). INTERVENTION: A structured group education programme for six hours delivered in the community by two trained healthcare professional educators compared with usual care. MAIN OUTCOME MEASURES: Haemoglobin A(1c) levels, blood pressure, weight, blood lipid levels, smoking status, physical activity, quality of life, beliefs about illness, depression, and emotional impact of diabetes at baseline and up to 12 months. MAIN RESULTS: Haemoglobin A(1c) levels at 12 months had decreased by 1.49% in the intervention group compared with 1.21% in the control group. After adjusting for baseline and cluster, the difference was not significant: 0.05% (95% confidence interval -0.10% to 0.20%). The intervention group showed a greater weight loss: -2.98 kg (95% confidence interval -3.54 to -2.41) compared with 1.86 kg (-2.44 to -1.28), P=0.027 at 12 months. The odds of not smoking were 3.56 (95% confidence interval 1.11 to 11.45), P=0.033 higher in the intervention group at 12 months. The intervention group showed significantly greater changes in illness belief scores (P=0.001); directions of change were positive indicating greater understanding of diabetes. The intervention group had a lower depression score at 12 months: mean difference was -0.50 (95% confidence interval -0.96 to -0.04); P=0.032. A positive association was found between change in perceived personal responsibility and weight loss at 12 months (beta=0.12; P=0.008). CONCLUSION: A structured group education programme for patients with newly diagnosed type 2 diabetes resulted in greater improvements in weight loss and smoking cessation and positive improvements in beliefs about illness but no difference in haemoglobin A(1c) levels up to 12 months after diagnosis. TRIAL REGISTRATION: Current Controlled Trials ISRCTN17844016 [controlled-trials.com].

'Educator talk' and patient change: some insights from the DESMOND (Diabetes Education and Self Management for Ongoing and Newly Diagnosed) randomized controlled trial.

AIMS: To determine whether differences in the amount of time educators talk during a self-management education programme relate to the degree of change in participants' reported beliefs about diabetes. METHOD: Educators trained to be facilitative and non-didactic in their approach were observed delivering the DESMOND self-management programme for individuals newly diagnosed with Type 2 diabetes. Observers used 10-s event coding to estimate the amount of time educators spoke during different sessions in the programme. Facilitative as opposed to didactic delivery was indicated by targets for levels of educator talk set for each session. Targets were based on earlier pilot work. Using the revised Illness Perceptions Questionnaire (IPQ-R) and the Diabetes Illness Representations Questionnaire (DIRQ), participants completed measures of: perceived duration of diabetes (timeline IPQ-R), understanding of diabetes (coherence IPQ-R), personal responsibility for influencing diabetes (personal responsibility IPQ-R), seriousness of diabetes (seriousness DIRQ) and impact on daily life (impact DIRQ), before and after the education programme. RESULTS: Where data from the event coding indicated educators were talking less and meeting targets for being less didactic, a greater change in reported illness beliefs of participants was seen. However, educators struggled to meet targets for most sessions of the programme. CONCLUSION: The amount of time educators talk in a self-management programme may provide a practical marker for the effectiveness of the education process, with less educator talk denoting a more facilitative/less didactic approach. This finding has informed subsequent improvements to a comprehensive quality development framework, acknowledging that educators need ongoing support to facilitate change to their normal educational style.

The natural history of overactive bladder and stress urinary incontinence in older women in the community: a 3-year prospective cohort study.

AIMS: This is the first study designed to describe the natural history of stress urinary incontinence (SUI) and overactive bladder (OAB), using validated symptom syndrome severity scores developed for the purpose. METHODS: Two separate but related studies were involved, (i) a clinic sample (N = 2,052) from a randomised controlled trial (RCT) and (ii) a prospective cohort study (N = 12,750) with 3-year follow-up. Subjects in both studies were women aged 40 or more living in the community, approached using similar postal questionnaires. Severity scores using standardised urinary symptoms were derived for SUI and OAB from weightings obtained from logistic regression models of symptoms in relation to urodynamic diagnosis. Symptom severity scores were plotted for baseline and 3 years of follow-up to demonstrate the natural history of the main categories of SUI and OAB. RESULTS: Overactive bladder and SUI syndrome severity scores showed good criterion validity in relation to relevant clinical measures and good test-retest reliability. OAB severity increased progressively with age including a period of accelerated increase in the 60s. In contrast, SUI severity showed two age-related peaks around age 60 and again at age 80. SUI severity also showed a more fluctuating pattern from year to year compared to OAB. CONCLUSIONS: Contrasting patterns of natural history for OAB and SUI syndromes were identified consistent with differences in the patterns of related co-morbidities. Further studies are needed to confirm these findings.

The cost of clinically significant urinary storage symptoms for community dwelling adults in the UK.

OBJECTIVES: To estimate the cost of clinically significant urinary storage symptoms (CSUSS), including costs borne by the National Health Service (NHS) and individuals, in terms of the use of goods and services in community-dwelling adults. SUBJECTS AND METHODS: The subjects were community-dwelling adults aged >/= 40 years and living in Leicestershire. The prevalence of CSUSS was estimated using a postal questionnaire with a randomly selected sample of 23 182 respondents. The costs associated with CSUSS were estimated using home interviews with 613 cases with and 523 subjects without CSUSS. Cases were defined on the basis of urinary symptoms of leakage, urgency, frequency and nocturia. Willingness-to-pay was used to measure intangible costs as an indicator of the value of alleviating symptoms. RESULTS: The estimated total annual cost to the NHS for treating CSUSS cases in community-dwelling adults was pound 536 million at 1999/2000 prices ( pound 303 million and pound 233 million for men and women, respectively). The total value of costs borne by individuals was estimated to be pound 207 million ( pound 29 million and pound 178 million for men and women, respectively). This gives total annual costs related to the use of services of pound 743 million. There were large intangible costs borne by individuals estimated to be pound 669 million ( pound 301 and pound 368 million for men and women) for the UK in terms of willingness-to-pay. CONCLUSIONS: The costs of CSUSS in the community amounted to approximately 1.1% of overall NHS spending for 1999/2000. Personally borne and intangible costs are also large and important components of the costs of CSUSS. There are large gender differences in the proportion of costs borne by the NHS, i.e. 91% of male and 57% of female costs.

Storage symptoms of the bladder: prevalence, incidence and need for services in the UK.

OBJECTIVE: To establish valid and reliable prevalence and incidence rates for urinary incontinence and storage disorder, and estimate the extent of healthcare need and requirement for the UK. SUBJECTS AND METHODS: This was a cross-sectional and longitudinal population-based study involving registrants with 108 general practices in Leicestershire and Rutland counties (UK). In all, 162 533 (prevalence study) and 39 602 (incidence study) people aged > or = 40 years were approached by postal questionnaire, with response rates of 60% and 63%, respectively; 1050 non-responders were followed up. The main measures were incontinence (involuntary leakage) storage disorder (including incontinence or urgency or frequency or nocturia above clinically defined thresholds), storage symptoms (as for storage disorder, above epidemiologically defined thresholds), professionally defined healthcare need (storage disorder, or storage symptoms with an impact on quality of life, QoL), and healthcare requirement (using services or wanting help among those with a healthcare need), all within the last year. RESULTS: The period prevalence was: moderate or greater incontinence, 16.1%; storage disorder, 28.5%; storage symptoms with impact on QoL, 30.4%; healthcare need, 37.1% and requirement 20.4%. Among those with storage disorders 81% reported effects on QoL. Annual incidence rates were: incontinence, 6.3%; storage disorder, 14.1%; healthcare need, 15.6% and requirement 8.4%. The remission rates were substantially greater in men than women. The problem becomes increasingly established and less likely to remit with age. CONCLUSIONS: In the UK over a 1-year period, over a third of people aged > or = 40 years are estimated to have a healthcare need for urinary storage symptoms (i.e. 9 million) and a fifth (i.e. 5 million) are estimated to require healthcare, with unmet requirement affecting 3 million. This represents a major public health problem. Apparent inconsistencies between prevalence, impact and uptake of services are explained.

The association of diet and other lifestyle factors with overactive bladder and stress incontinence: a longitudinal study in women.

OBJECTIVES: To investigate the role of diet and other lifestyle factors in the incidence of overactive bladder and stress incontinence in women. Studies have suggested relationships between different aspects of lifestyle and symptoms of urinary incontinence, but there is a lack of firm evidence about their role in its cause. SUBJECTS AND METHODS: A random sample of women aged >or= 40 years living at home took part in a prospective cohort study. Baseline data on urinary symptoms, diet and lifestyle were collected from 7046 women using a postal survey and food-frequency questionnaire. Follow-up data on urinary symptoms were collected from 6424 of the women in a postal survey 1 year later. Logistic regression was used to investigate the association of food and drink consumption and other lifestyle factors with the incidence of overactive bladder and stress incontinence. RESULTS: In the multivariate model for the onset of an overactive bladder, there were significantly increased risks associated with obesity, smoking and consumption of carbonated drinks, and reduced risks with higher consumption of vegetables, bread and chicken. Obesity and carbonated drinks were also significant risk factors for the onset of stress incontinence, while consumption of bread was associated with a reduced risk. CONCLUSIONS: Causal associations with obesity, smoking and carbonated drinks are confirmed for bladder disorders associated with incontinence, and additional associations with diet are suggested. Behavioural modification of lifestyle may be important for preventing and treating these disorders.

An investigation into nonresponse bias in a postal survey on urinary symptoms.

OBJECTIVE: To investigate nonresponse bias in a postal survey on urinary symptoms in people aged >or= 40 years. SUBJECTS AND METHODS: Nonresponders to a postal survey on incontinence and other urinary symptoms were studied. A random sample of 1050 nonresponders (stratified for age and sex) was traced by a team of interviewers. Eligible nonresponders were asked several questions from the postal questionnaire, and their reason for not participating in the postal survey. RESULTS: Only 1% of those not responding were not traced in person or accounted for, and 12% were identified as not eligible to be in the survey sample (moved from address, deceased, residential home). Half of the eligible nonresponders (51%) did not answer the interviewer's questions, the main reason being general unwillingness or disinterest. The number in whom poor health was the reason increased with age. Comparing nonresponders who answered the interviewer's questions with a random sample of responders from the postal survey showed little difference in the reporting of urinary symptoms, although there were differences in general health and long-term health problems. Separate analyses by age showed greater reporting of some urinary symptoms and of poorer general health in the older nonresponders (>or= 70 years). CONCLUSION: Overall, for people aged >or= 40 years there was no evidence of a nonresponse bias in the reporting of urinary symptoms, providing confidence in such prevalence rates. However, poorer general health and greater reporting of some urinary symptoms by the older nonresponders (>or= 70 years) suggests prevalence rates in this age group may be underestimated.

Normal values for weight, skeletal size and body mass indices in 890 men and women aged over 65 years.

Measurements of body weight and skeletal size have been made, as part of a demographically representative survey, in 532 women and 358 men aged over 65 years living in their own homes. Body weight was assessed using calibrated portable scales. Skeletal size was measured as half body span (demispan) using a steel tape stretched from the sternal notch to the finger roots. Age had a weak but significant negative association with both body weight and demispan. After controlling for demispan, age still accounted for a significant decline in weight (in kg per decade) of 2.5 in men and 3.5 in women. Weight, demispan and indices of weight-for-skeletal-size have been presented as percentiles for men and women separately.

Normal values for range of shoulder abduction in men and women aged over 65 years.

The range of movement of the shoulder in abduction at 45 degrees of flexion was objectively measured using a standard technique in a demographically representative survey of 1000 men and women living in their own homes. Sampling was stratified to obtain approximately equal numbers of those aged 65-74 years and those aged 75 and over. The response rate was 80%. Normal values for shoulder abduction grouped by age and sex are presented as frequency distributions, means and deciles. Information about health problems was also recorded in the survey; the prevalences of these problems and their associations with shoulder abduction have been investigated. Women had significantly lower values for shoulder abduction than men. For both sexes values were on average about 30 degrees lower than those found in younger adults, and about half of the elderly group had values below 120 degrees. The prevalence of specified health problems was high with only 3% of the older group and 6% of the younger group being free from all the specified health problems. There was a significant independent negative association between shoulder abduction and both age and reported health. The associations were more marked in women than in men. This was so for both a cumulated 14-item health index and selected individual health items which included arthritis, lack of mobility and incontinence. The decile values for shoulder abduction for women without these health problems are presented. This provides more appropriate normal data for them; it is more normally distributed and reduces the percentage with a shoulder abduction less than 120 degrees to 30%.(ABSTRACT TRUNCATED AT 250 WORDS)

Flexibility of the shoulder joint measured as range of abduction in a large representative sample of men and women over 65 years of age.

In a representative survey of 1000 elderly men and women aged over 65 years living in their own homes, assessments have been made of flexibility measured as range of shoulder abduction in addition to health status, psychological well-being and reported customary activity. The results for shoulder abduction were approximately normally distributed and the mean values (+/- 1 standard deviation) were as follows: - in men aged 65-74 years, 129 (+/- 14) degrees and aged over 74 years, 121 (+/- 19) degrees; in women aged 65-74 years, 124 (+/- 19) degrees and aged over 74 years, 114 (+/- 22) degrees. These mean values are about 30 degrees less than those accepted for younger subjects. Nearly half the distribution falls below the accepted threshold level of 120 degrees for adequate function. There were significant effects of sex and age (P less than 0.001); women had poorer flexibility and the reduction with age amounted to 10 degrees per decade. Multiple regression analysis showed that the effect of age was accounted for in part by health, strength and customary use. The effects of use were most marked in those with some disability. This suggests that maintained or increased use could offset some of the age-related loss of the range of shoulder movement.

Levels of customary physical activity among the old and the very old living at home.

With an activity inventory designed specifically for use among elderly people, detailed profiles of customary physical activity were obtained from 507 old (aged 65-74 years) and 535 very old (aged 75 years and over) individuals randomly sampled from the community. Participation in four categories of activity was assessed: outdoor productive activities; indoor productive activities; leisure activities; and walking. Customary engagement in many activities was found to be low, age (old versus very old) and sex being among the most important determinants of participation. The method of assessment is described, and activity profiles normative for older age groups are presented.

Mental health and psychological well-being among the old and the very old living at home.

Using four brief assessment scales, profiles of mental health and psychological well-being were obtained from 507 old (aged 65-74 years) and 535 very old (aged 75+) individuals randomly sampled from the community. Assessments of dementia and depression were subsequently validated against diagnostic ratings made by experienced psychogeriatricians. Levels of agreement between psychometric and clinical ratings of dementia (kappa = 0.83) and depression (kappa = 0.66) were satisfactory. The old and very old groups reported similar levels of anxiety and personal disturbance, and showed a similar prevalence of depression. However, those aged 75+ showed higher levels of dementia and significantly lower levels of social involvement and morale.

Validation of a simple mechanical accelerometer (pedometer) for the estimation of walking activity.

A small (28 g) mechanical accelerometer has been tested by subjecting it to controlled bench tests consisting of repetitive vertical oscillations on two designs of test rig. The accelerometer's 3-digit display provided a cumulated score with a maximum of 99.9 units. This score was compared with an independent count of the imposed oscillations and found to be linear with time (r = 0.996) and reproducible on retest (coefficient of variation = +/- 1.5%). The sensitivity ranged from 6.2 to 7.4 units/10,000 oscillations. The response was related to the maximal applied acceleration (calculated from the amplitude and frequency of the oscillations on the assumption that they were sinusoidal) and independent of the amplitude and frequency used. The threshold maximal acceleration was less than 2 m s-2 and the response had reached a plateau at 4 m s-2. During field studies the accelerometer was firmly attached over the hip in a waistband where it responded to the vertical accelerations produced by walking. When compared with an independent count of footsteps from a heel-mounted resistance pad the accelerometer score (after calibration) was not significantly different. The mean difference was (0.29 +/- 0.67, S.D.) 10(3) "steps" in a younger group (n = 8, mean age 39 years) and (0.46 +/- 1.08, S.D.) 10(3) "steps" in an older group of women (n = 6, mean age 65 years). Scores of around 10 X 10(3) "steps" can be expected in a day in moderately active young subjects and 40 X 10(3) "steps" in a week in the elderly. Simultaneously recorded scores from both right and left hips wee not significantly different.(ABSTRACT TRUNCATED AT 250 WORDS)

Whole-body calorimetry studies in adult men. 1. The effect of fat over-feeding on 24 h energy expenditure.

Eight young men of normal weight were maintained for 1 week on a weight-maintenance diet followed by a 1-week period of over-feeding with extra fat designed to increase energy intake by 50%. Two 36 h calorimetry sessions with low and high physical activities were included in each feeding period. Faecal and urine collections permitted checks on energy malabsorption and nitrogen excretion. Over-feeding led to increases in body-weight, faecal energy and N excretion and in estimated N retention. Faecal energy outputs on the maintenance and over-feeding diets were 5 and 4.4% of the respective gross energy intakes. Energy expenditure on fat over-feeding increased by 5.6% on the low-activity regimen and 6.4% on the high-activity regimen. This amounted, in terms of the extra energy intake, to 9 and 11% on the inactive and active schedules respectively. The increase affected day- and night-time rates of energy expenditure plus the basal metabolic rate. Individuals with a low percentage body fat showed the greatest response to over-feeding. Nutrient-balance studies derived from calorimetry suggested that fat over-feeding led to substantial fat deposition with no evidence of sparing of carbohydrate oxidation. The theoretical cost of depositing dietary fat was exceeded, suggesting that regulatory thermogenic mechanisms may have been stimulated to a small extent.

Whole-body calorimetry studies in adult men. 2. The interaction of exercise and over-feeding on the thermic effect of a meal.

Studies have claimed that an enhancement of the thermic effect of a meal (TEM) is an important adaptive mechanism to account for energy wastage during over-feeding. Eight healthy normal-weight young men were studied during 1 week on a weight-maintenance diet and again during 1 week when they were over-fed by 50% with fat. During each experimental week, the subject occupied a whole-body indirect calorimeter at 26 degrees for two separate periods of 36 h. The periods differed in the amount of exercise they contained. The thermic responses to the identical meals were measured during rest on one occasion and during exercise on a bicycle ergometer on the other. On the maintenance diet the absolute TEM (kJ/min) was 1.51 (SD 0.42) at rest and 1.31 (SD 0.75) during exercise (no significant difference). The equivalent values (kJ/min) on the over-feeding diet were 2.2 (SD 0.48) and 1.97 (SD 0.64) (no significant difference). The absence of a significant interaction between TEM and exercise was also demonstrated by the fact that the effect of over-feeding on total 24 h energy expenditure was unaffected by the subject's level of physical activity while in the calorimeter. In conclusion, the present study has provided no evidence to support the hypothesis that TEM is enhanced during exercise.